References.bib

@article{dorn_generalizations_1962,
	title = {Generalizations of {Horner}'s {Rule} for {Polynomial} {Evaluation}},
	volume = {6},
	issn = {0018-8646},
	doi = {10.1147/rd.62.0239},
	abstract = {Polynomials are generally evaluated by use of Horner's rule, sometimes referred to as the nesting rule. This rule is sequential and affords no opportunity for parallel computation, i.e., completion of several of the arithmetic operations simultaneously. Two generalizations of Horner's rule which allow for parallel computation are presented here. Schedules and, in some cases, machine codes for evaluating a polynomial on a computer with several parallel arithmetic units are developed. Some advantages of the generalized rules in sequential computations on a computer with a single arithmetic unit are presented.},
	number = {2},
	journal = {IBM Journal of Research and Development},
	author = {Dorn, W.S.},
	month = apr,
	year = {1962},
	pages = {239--245}
}

@book{brekhovskikh_waves_1980,
	title = {Waves in layered media},
	isbn = {978-0-12-130560-4},
	language = {en},
	publisher = {Academic Press},
	author = {Brekhovskikh, Leonid Maksimovich},
	year = {1980},
	keywords = {Science / General, Science / Waves \& Wave Mechanics, Waves}
}

@article{seo_sidelobe_2008,
	title = {Sidelobe suppression in ultrasound imaging using dual apodization with cross-correlation},
	volume = {55},
	issn = {0885-3010},
	doi = {10.1109/TUFFC.919},
	abstract = {This paper introduces a novel sidelobe and clutter suppression method in ultrasound imaging called dual apodization with cross-correlation or DAX. DAX dramatically improves the contrast-to-noise ratio (CNR) allowing for easier visualization of anechoic cysts and blood vessels. This technique uses dual apodization or weighting strategies that are effective in removing or minimizing clutter and efficient in terms of computational load and hardware/software needs. This dual apodization allows us to determine the amount of mainlobe versus clutter contribution in a signal by cross-correlating RF data acquired from 2 apodization functions. Simulation results using a 128 element 5 MHz linear array show an improvement in CNR of 139\% compared with standard beamformed data with uniform apodization in a 3 mm diameter anechoic cylindrical cyst. Experimental CNR using a tissue-mimicking phantom with the same sized cyst shows an improvement of 123\% in a DAX processed image.},
	number = {10},
	journal = {IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control},
	author = {Seo, Chi Hyung and Yen, J.T.},
	month = oct,
	year = {2008},
	keywords = {Algorithms, anechoic cylindrical cyst, Artifacts, Biomedical engineering, biomedical ultrasonics, blood vessels, Computational modeling, contrast-to-noise ratio, Cysts, dual apodization, Frequency, Gratings, Humans, Image Enhancement, Image Interpretation, Computer-Assisted, Linearity, phantoms, Phantoms, Imaging, Reproducibility of Results, Scattering, Sensitivity and Specificity, sidelobe suppression, Signal design, Signal resolution, Speckle, Statistics as Topic, tissue-mimicking phantom, ultrasonic imaging, Ultrasonography, ultrasound imaging, visualization, weighting strategies},
	pages = {2198--2210},
	file = {IEEE Xplore Abstract Record:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\JWPP6RJB\\articleDetails.html:text/html;IEEE Xplore Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\V77ET2B2\\Seo and Yen - 2008 - Sidelobe suppression in ultrasound imaging using d.pdf:application/pdf}
}

@article{choe_gpu-based_2013,
	title = {{GPU}-{Based} {Real}-{Time} {Volumetric} {Ultrasound} {Image} {Reconstruction} for a {Ring} {Array}},
	volume = {32},
	issn = {0278-0062},
	url = {http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4019434/},
	doi = {10.1109/TMI.2013.2253117},
	abstract = {Synthetic phased array (SPA) beamforming with Hadamard coding and aperture weighting is an optimal option for real-time volumetric imaging with a ring array, a particularly attractive geometry in intracardiac and intravascular applications. However, the imaging frame rate of this method is limited by the immense computational load required in synthetic beamforming. For fast imaging with a ring array, we developed graphics processing unit (GPU)-based, real-time image reconstruction software that exploits massive data-level parallelism in beamforming operations., The GPU-based software reconstructs and displays three cross-sectional images at 45 frames per second (fps). This frame rate is 4.5 times higher than that for our previously-developed multi-core CPU-based software. In an alternative imaging mode, it shows one B-mode image rotating about the axis and its maximum intensity projection (MIP), processed at a rate of 104 fps. This paper describes the image reconstruction procedure on the GPU platform and presents the experimental images obtained using this software.},
	number = {7},
	urldate = {2015-06-27},
	journal = {IEEE Transactions on Medical Imaging},
	author = {Choe, Jung Woo and Nikoozadeh, Amin and Oralkan, Ömer and Khuri-Yakub, Butrus T.},
	month = jul,
	year = {2013},
	pages = {1258--1264}
}

@article{phuong_design_2015,
	title = {Design space exploration of {SW} beamformer on {GPU}},
	volume = {27},
	copyright = {Copyright © 2014 John Wiley \& Sons, Ltd.},
	issn = {1532-0634},
	url = {http://onlinelibrary.wiley.com/doi/10.1002/cpe.3326/abstract},
	doi = {10.1002/cpe.3326},
	abstract = {Ultrasound imaging has become one of the most widely used modalities in medical diagnosis today. However, real-time ultrasound imaging requires large amount of data transfer and massive computation and therefore mainly relies on a complex dedicated hardware system. A recent trend of a graphics processing unit (GPU) based software-based approach offers the advantages of flexibility and quick implementation. The GPUs have been reported as excellent accelerators across a wide range of applications. For best exploiting outstanding computational power and high memory bandwidth of a GPU, the paper explores the design space of implementing an ultrasound beamformer on a GPU platform. The design spaces are expanded by applying different optimization strategies to the beamformer on a GPU platform, and we also discuss the performance evaluation results on the various GPUs whose architectural characteristics are different to each others. The performance analysis shows that by optimizing CUDA code, our real-time-GPU-based beamformer can be successfully implemented with 181 frames per second (fps) and speedup of 230.6X compared with the single-threaded implementation on a high-performance CPU platform. Copyright © 2014 John Wiley \& Sons, Ltd.},
	language = {en},
	number = {7},
	urldate = {2015-06-27},
	journal = {Concurrency and Computation: Practice and Experience},
	author = {Phuong, Thi Yen and Lee, Jeong-Gun},
	month = may,
	year = {2015},
	keywords = {beamforming, B-mode imaging, CUDA, GPU, parallel processing, ultrasound imaging},
	pages = {1718--1733}
}

@inproceedings{gjerald_real-time_2011,
	title = {Real-time ultrasound simulation using the {GPU}},
	doi = {10.1109/ULTSYM.2011.0063},
	abstract = {In many ultrasound simulators for training purposes, synthetic ultrasound images have to be generated in real time. Patient specific anatomy can be modeled by using computed tomography (CT) data, and shadows can be calculated by using reflection coefficients and depth dependent, exponential attenuation. In order to include speckle, a pre-calculated texture map is typically added and blurred laterally to include an anisotropic point spread function (PSF). We propose to increase the speckle realism and allow for dynamic objects by using a physical model of the underlying scattering process. The scattering process is simulated as a convolution of the PSF of the ultrasound scanner with a scatterer distribution. The challenge is that the typical field-of-view (FOV) contains millions of scatterers which have to be selected by a virtual probe from an even larger body of scatterers. The main idea of this paper is to select and sample scatterers in parallel on the graphic processing unit (GPU). Ultrasound images of homogeneous tissue were produced in real time on a standard GPU (more than 10 frames per second). The ultrasound images were visually similar to images calculated by a reference method.},
	booktitle = {Ultrasonics {Symposium} ({IUS}), 2011 {IEEE} {International}},
	author = {Gjerald, Sjur Urdson and Brekken, Reidar and Hergum, Torbjorn and D'hooge, Jan},
	month = oct,
	year = {2011},
	keywords = {Graphics processing unit, Instruction sets, phantoms, Real time systems, Solid modeling, ultrasonic imaging},
	pages = {258--261}
}

@article{degraaf_sidelobe_1994,
	title = {Sidelobe reduction via adaptive {FIR} filtering in {SAR} imagery},
	volume = {3},
	issn = {1057-7149},
	doi = {10.1109/83.287022},
	abstract = {The paper describes a class of adaptive weighting functions that greatly reduce sidelobes, interference, and noise in Fourier transform data. By restricting the class of adaptive weighting functions, the adaptively weighted Fourier transform data can be represented as the convolution of the unweighted Fourier transform with a data adaptive FIR filter where one selects the FIR filter coefficients to maximize signal-to-interference ratio. This adaptive sidelobe reduction (ASR) procedure is analogous to Capon's (1969) minimum variance method (MVM) of adaptive spectral estimation. Unlike MVM, which provides a statistical estimate of the real-valued power spectral density, thereby estimating noise level and improving resolution, ASR provides a single-realization complex-valued estimate of the Fourier transform that suppresses sidelobes and noise. Further, the computational complexity of ASR is dramatically lower than that of MVM, which is critical for large multidimensional problems such as synthetic aperture radar (SAR) image formation. ASR performance characteristics can be varied through the choice of filter order, l(1)- or l(2)-norm filter vector constraints and a separable or nonseparable multidimensional implementation. The author compares simulated point scattering SAR imagery produced by the ASR, MVM, and MUSIC algorithms and illustrates ASR performance on three sets of collected SAR imagery.},
	language = {eng},
	number = {3},
	journal = {IEEE Transactions on Image Processing},
	author = {Degraaf, S R},
	year = {1994},
	pages = {292--301}
}

@inproceedings{zhang_ray-based_2006,
	title = {Ray-based {Simulations} of {Received} {Signals} from {Ground} {Penetrating} {Radar}},
	doi = {10.1109/ICR.2006.343513},
	abstract = {Numerical simulation of ground penetrating radar (GPR) signals is potentially valuable in both survey design and data interpretation. We develop a method for numerically synthesizing GPR received signals using geometrical ray theory. The GPR reflected ray tracing scheme is implemented using wave front expanding method, based on Fermat's principle, reciprocity principle, and Dijkstra's shortest path algorithm. This method is good for complex layered models with inhomogeneous material and undulate interfaces, and can trace all reflected ray paths from one non-planar interface at one time, for a pair of source and receiver. Simulation experiments show it is effective},
	booktitle = {International {Conference} on {Radar}, 2006. {CIE} '06},
	author = {Zhang, Jianzhong and Li, Feng and Yang, Guohui},
	month = oct,
	year = {2006},
	keywords = {complex layered models, data interpretation, Dijkstra's shortest path algorithm, electromagnetic wave reflection, Fermat's principle, geometrical ray theory, GPR, ground penetrating radar, inhomogeneous material, numerical analysis, numerical simulation, radar receivers, radar signal processing, ray-based simulations, ray tracing, ray tracing scheme, receiver, reciprocity principle, wave front expanding method},
	pages = {1 --4},
	file = {IEEE Xplore Abstract Record:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\TG985UG6\\articleDetails.html:text/html;IEEE Xplore Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\T7M7VV6S\\Zhang et al. - 2006 - Ray-based Simulations of Received Signals from Gro.pdf:application/pdf}
}

@article{sakhaei_optimum_2012,
	title = {Optimum beamforming for sidelobe reduction in ultrasound imaging},
	volume = {59},
	issn = {1525-8955},
	doi = {10.1109/TUFFC.2012.2257},
	abstract = {A constrained adaptive beamforming in a deterministic sense is considered for side lobe reduction, leading to an adaptive weighting of the uniform delay-and-sum beamformer; based upon this, the coherence factor and other similar methods are interpreted as beamforming methods. A generalized form of the weighting factor for the side lobe reduction is also established. It is shown through simulations that restricting the apodization vector to a parametric representation through a discrete Fourier transform or discrete cosine transform can result in higher quality images with fewer artifacts and enhanced contrast properties compared with images obtained through the coherence factor-like methods.},
	language = {eng},
	number = {4},
	journal = {IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control},
	author = {Sakhaei, Sayed Mahmoud},
	month = apr,
	year = {2012},
	pmid = {22547290},
	keywords = {Computer Simulation, Fourier Analysis, Image Processing, Computer-Assisted, Models, Biological, Phantoms, Imaging, Ultrasonography},
	pages = {799--805}
}

@article{vignon_capon_2008,
	title = {Capon beamforming in medical ultrasound imaging with focused beams},
	volume = {55},
	issn = {0885-3010},
	doi = {10.1109/TUFFC.2008.686},
	abstract = {Medical ultrasound imaging is conventionally done by insonifying the imaged medium with focused beams. The backscattered echoes are beamformed using delay-and-sum operations that cannot completely eliminate the contribution of signals backscattered by structures off the imaging beam to the beamsum. It leads to images with limited resolution and contrast. This paper presents an adaptation of the Capon beamformer algorithm to ultrasound medical imaging with focused beams. The strategy is to apply data-dependent weight functions to the imaging aperture. These weights act as lateral spatial filters that filter out off-axis signals. The weights are computed for each point in the imaged medium, from the statistical analysis of the signals backscattered by that point to the different elements of the imaging probe when insonifying it with different focused beams. Phantom and in vivo images are presented to illustrate the benefits of the Capon algorithm over the conventional delay and-sum approach. On heart sector images, the clutter in the heart chambers is decreased. The endocardium border is better defined. On abdominal linear array images, significant contrast and resolution enhancement are observed.},
	language = {eng},
	number = {3},
	journal = {IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control},
	author = {Vignon, Francois and Burcher, Michael R},
	month = mar,
	year = {2008},
	pmid = {18407851},
	keywords = {Algorithms, Image Enhancement, Image Interpretation, Computer-Assisted, Reproducibility of Results, Sensitivity and Specificity, Signal Processing, Computer-Assisted, Ultrasonography},
	pages = {619--628}
}

@article{asl_minimum_2009,
	title = {Minimum variance beamforming combined with adaptive coherence weighting applied to medical ultrasound imaging},
	volume = {56},
	issn = {1525-8955},
	doi = {10.1109/TUFFC.2009.1268},
	abstract = {Currently, the nonadaptive delay-and-sum (DAS) beamformer is used in medical ultrasound imaging. However, due to its data-independent nature, DAS leads to images with limited resolution and contrast. In this paper, an adaptive minimum variance (MV)-based beamformer that combines the MV and coherence factor (CF) weighting is introduced and adapted to medical ultrasound imaging. MV-adaptive beamformers can improve the image quality in terms of resolution and sidelobes by suppressing off-axis signals, while keeping onaxis ones. In addition, CF weighting can improve contrast and sidelobes by emphasizing the in-phase signals and reducing the out-of-phase ones. Combining MV and CF weighting results in simultaneous improvement of imaging resolution and contrast, outperforming both DAS and MV beamformers. In addition, because of the power of CF in reducing the focusing errors, the proposed method presents satisfactory robustness against sound velocity inhomogeneities, outperforming the regularized MV beamformer. The excellent performance of the proposed beamforming approach is demonstrated by several simulated examples.},
	language = {eng},
	number = {9},
	journal = {IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control},
	author = {Asl, Babak Mohammadzadeh and Mahloojifar, Ali},
	month = sep,
	year = {2009},
	pmid = {19811995},
	keywords = {Algorithms, Computer Simulation, Image Processing, Computer-Assisted, Phantoms, Imaging, Signal Processing, Computer-Assisted, Ultrasonography},
	pages = {1923--1931}
}

@article{holmes_post-processing_2005,
	title = {Post-processing of the full matrix of ultrasonic transmit–receive array data for non-destructive evaluation},
	volume = {38},
	issn = {09638695},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0963869505000721},
	doi = {10.1016/j.ndteint.2005.04.002},
	number = {8},
	journal = {NDT \& E International},
	author = {Holmes, C and Drinkwater, B and Wilcox, P},
	month = dec,
	year = {2005},
	keywords = {arrays, post-processing, ultrasonics},
	pages = {701--711}
}

@article{nilsen_beamspace_2009,
	title = {Beamspace adaptive beamforming for ultrasound imaging},
	volume = {56},
	issn = {1525-8955},
	doi = {10.1109/TUFFC.2009.1301},
	abstract = {Applying the Capon adaptive beamformer in medical ultrasound imaging results in enhanced resolution by improving the interference-suppressing capabilities of the array. This improvement comes at the expense of an increased computational complexity. We have investigated the application of a beamspace adaptive beamformer for medical ultrasound imaging, which can be used to achieve reduced computational complexity with performance comparable to that of the Capon beamformer. The idea behind beamspace beamforming is that, instead of using the spatial statistics of the elements in the array to differentiate between signals and interference, we use the spatial statistics of a set of orthogonal beams, which are formed in different directions. This represents a shift from element space to beamspace. Because the majority of interference in medical ultrasound imaging is constrained to a limited spatial interval due to the focused transmit beam, this latter space can be reduced to a dimension that is lower than that of element space. We show, using simulations and experimental data, that this dimension can be selected as low as 3 while still achieving performance comparable to its element space counterpart.},
	language = {eng},
	number = {10},
	journal = {IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control},
	author = {Nilsen, Carl-Inge Colombo and Hafizovic, Ines},
	month = oct,
	year = {2009},
	pmid = {19942506},
	keywords = {Algorithms, Phantoms, Imaging, Signal Processing, Computer-Assisted, Ultrasonography},
	pages = {2187--2197}
}

@inproceedings{cassereau_theoretical_1994,
	title = {Theoretical and experimental analysis of focusing techniques through liquid-solid interfaces},
	volume = {2},
	doi = {10.1109/ULTSYM.1994.401720},
	abstract = {Different approaches have been extensively studied in order to obtain optimal focused beams through liquid-solid interfaces. In this paper, we compare two different focusing techniques: the standard Fermat's surface (FS) method and the time reversal (TR) approach. A FS transducer is designed such that the propagation times between the points on its surface and the desired focal point are equal. This method suffers from limitations, it needs the a priori knowledge of the geometry of the interface as well as the feature of the propagating medium. The TR method is based on the concept of time reversal of ultrasonic fields and takes into account the whole information coming from the sample. This technique is self adaptive and only requires the presence of a target in the solid sample, In this paper, we are interested in focusing an acoustic pressure field through a plane interface separating a liquid and a solid. Numerical and experimental results obtained with a 2D array are presented to compare the performances of the two techniques. These results demonstrate the ability of the TR technique to compensate automatically for the distortions induced by the interface},
	booktitle = {, 1994 {IEEE} {Ultrasonics} {Symposium}, 1994. {Proceedings}},
	author = {Cassereau, D. and Chakroun, N. and Fink, M. and Wu, F.},
	month = nov,
	year = {1994},
	keywords = {2D array, acoustic focusing, acoustic pressure field, acoustic transducers, compensation, distortions compensation, Fermat surface method, focusing techniques, liquid-solid interfaces, NDT, nondestructive testing, optimal focused beams, plane interface, time reversal method, ultrasonic fields, ultrasonic focusing, ultrasonic materials testing, ultrasonic transducer arrays, US transducers},
	pages = {1075 --1080 vol.2},
	file = {IEEE Xplore Abstract Record:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\VVS297BR\\articleDetails.html:text/html;IEEE Xplore Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\GTIXNUJB\\Cassereau et al. - 1994 - Theoretical and experimental analysis of focusing .pdf:application/pdf}
}

@article{li_adaptive_2003,
	title = {Adaptive imaging using the generalized coherence factor},
	volume = {50},
	issn = {0885-3010},
	abstract = {Sound-velocity inhomogeneities degrade both spatial and contrast resolutions. This paper proposes a new adaptive imaging technique that uses the generalized coherence factor (GCF) to reduce the focusing errors resulting from the sound-velocity inhomogeneities. The GCF is derived from the spatial spectrum of the received aperture data after proper receive delays have been applied. It is defined as the ratio of the spectral energy within a prespecified low-frequency range to the total energy. It is demonstrated that the low-frequency component of the spectrum corresponds to the coherent portion of the received data, and that the high-frequency component corresponds to the incoherent portion. Hence, the GCF reduces to the coherence factor defined in the literature if the prespecified low-frequency range is restricted to dc only. In addition, the GCF is also an index of the focusing quality and can be used as a weighting factor for the reconstructed image. The efficacy of the GCF technique is demonstrated for focusing errors resulting from the sound-velocity inhomogeneities. Simulations and real ultrasound data are used to evaluate the efficacy of the proposed GCF technique. The characteristics of the GCF, including the effects of the signal-to-noise ratio and the number of channels, are also discussed. The GCF technique also is compared with the correlation-based technique and the parallel adaptive receive compensation algorithm; the improvement in image quality obtained with the proposed technique rivals that of the latter technique. In the presence of a displaced phase screen, this proposed technique also outperforms the correlation-based technique. Computational complexity and implementation issues also are addressed.},
	language = {eng},
	number = {2},
	journal = {IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control},
	author = {Li, Pai Chi and Li, Meng Lin},
	month = feb,
	year = {2003},
	pmid = {12625586},
	keywords = {Algorithms, Artifacts, Computer Simulation, Cysts, Feedback, Humans, Image Enhancement, Models, Biological, Phantoms, Imaging, Quality Control, Scattering, Radiation, Sensitivity and Specificity, Stochastic Processes, Transducers, Ultrasonography},
	pages = {128--141}
}

@article{jeong_fourier_2000,
	title = {A {Fourier} transform-based sidelobe reduction method in ultrasound imaging},
	volume = {47},
	issn = {0885-3010},
	doi = {10.1109/58.842066},
	abstract = {Focusing is widely used to increase the resolution in medical ultrasound imaging systems. Focusing increases signal levels returning from the mainlobe direction and decreases those from sidelobe directions. The sidelobes, when not completely cancelled, deteriorate the resulting image resolution. This paper proposes a method of improving the resolution by scaling the received signal according to the ratio between the mainlobe and the sidelobe levels computed in the frequency domain by the use of Fourier transform. The proposed method is verified by computer simulation and experiment and is shown to be highly effective in narrowing the mainlobe width and decreasing the sidelobe levels at the same time.},
	language = {eng},
	number = {3},
	journal = {IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control},
	author = {Jeong, M K},
	year = {2000},
	pmid = {18238606},
	pages = {759--763}
}

@article{nilsen_wiener_2010,
	title = {Wiener beamforming and the coherence factor in ultrasound imaging},
	volume = {57},
	issn = {1525-8955},
	doi = {10.1109/TUFFC.2010.1553},
	abstract = {The coherence factor (CF) is used for aberration correction and sidelobe suppression in ultrasound imaging. Unfortunately, it suffers from artifacts when the SNR is low. We show how the CF can be interpreted as an implementation of the Wiener postfilter for a delay-and-sum beamformer. In addition, we show that a minimum-variance, distortionless-response beamformer followed by CF weighting can be interpreted as an implementation of the Wiener beamformer. These interpretations provide us with a theoretical framework for analyzing and improving CF-based methods. We use this theory to develop more robust implementations for both the Wiener postfilter and beamformer. The performance of these implementations is shown on simulated and real data.},
	language = {eng},
	number = {6},
	journal = {IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control},
	author = {Nilsen, Carl-Inge and Holm, Sverre},
	month = jun,
	year = {2010},
	pmid = {20529709},
	keywords = {Algorithms, Computer Simulation, Cysts, Databases, Factual, Humans, Image Processing, Computer-Assisted, Models, Theoretical, Ultrasonography},
	pages = {1329--1346}
}

@article{camacho_phase_2009,
	title = {Phase coherence imaging},
	volume = {56},
	issn = {1525-8955},
	doi = {10.1109/TUFFC.2009.1128},
	abstract = {A new method for grating and side lobes suppression in ultrasound images is presented. It is based on an analysis of the phase diversity at the aperture data. Two coherence factors, namely the phase coherence factor (PCF) and the sign coherence factor (SCF), are proposed to weight the coherent sum output. Different from other approaches, phase rather than amplitude information is used to perform the correction action. Besides achieving the main goal, the method obtains improvements in lateral resolution and SNR. Implementation of the SCF technique is quite straightforward, operating in realtime, and can be added to any virtually existing beamformer to improve the resolution, contrast, SNR, and dynamic range of the images. A programmable parameter allows adjusting the sensitivity of the method to out-of-phase signals, from zero to a strict coherence criterion. The theoretical basis for the 2 methods are given and their performances evaluated by simulation. Then, experiments are conducted to provide results that are in good agreement with those expected from theory and simulation.},
	number = {5},
	journal = {IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control},
	author = {Camacho, Jorge and Parrilla, Montserrat and Fritsch, Carlos},
	month = may,
	year = {2009},
	pmid = {19473914},
	keywords = {Algorithms, Computer Simulation, Phantoms, Imaging, Signal Processing, Computer-Assisted, Ultrasonography},
	pages = {958--974}
}

@article{camacho_phase_2011,
	title = {Phase coherence imaging of grained materials},
	volume = {58},
	issn = {0885-3010},
	doi = {10.1109/TUFFC.2011.1901},
	abstract = {Ultrasound detection and evaluation of flaws in materials showing structural noise (austenitic steels, titanium alloys, composites, etc.) is difficult because of the low flaw-to-grain noise ratio. Much research has been performed looking for methods to improve flaw detection in grained materials. Many approaches require a cumbersome tuning process to select the correct parameter values or to use iterative techniques. In this work, the technique of phase coherence imaging is proposed to improve the flaw-to-grain noise ratio. The technique weights the output of a conventional beamformer with a coherence factor obtained from the aperture data phase dispersion. It can be simply implemented in real-time and it operates automatically, without needing any parameter adjustment. This paper presents the theoretical basis of phase coherence imaging to reduce grain noise, as well as experimental results that confirm the expected performance.},
	number = {5},
	journal = {IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control},
	author = {Camacho, J. and Fritsch, C.},
	month = may,
	year = {2011},
	keywords = {aperture data phase dispersion, Apertures, Arrays, Coherence, coherence factor, flaw detection, flaw-to-grain noise ratio, Focusing, grained materials, grain noise, Materials, noise, phase coherence imaging, ultrasonic detection, ultrasonic imaging, ultrasonic materials testing},
	pages = {1006--1015},
	file = {IEEE Xplore Abstract Record:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\6SJKQT9J\\abs_all.html:text/html;IEEE Xplore Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\W96DVCFS\\Camacho and Fritsch - 2011 - Phase coherence imaging of grained materials.pdf:application/pdf}
}

@article{weston_time_2012,
	title = {Time efficient auto-focussing algorithms for ultrasonic inspection of dual-layered media using {Full} {Matrix} {Capture}},
	volume = {47},
	issn = {0963-8695},
	url = {http://www.sciencedirect.com/science/article/pii/S0963869511001526},
	doi = {10.1016/j.ndteint.2011.10.006},
	abstract = {This paper describesa number ofmethods for calculating the point of incidence at a planarrefractive interface between dual-layered media for ultrasonic applications in the field of non-destructive testing. It is shown how Snell's law may be expressed as a quartic polynomial, and solved using analytical or numerical techniques to find the point of incidence at the refractive interface. An array transducer mounted onto a Perspex wedge is used to generate ultrasonic imagery of a double ‘v’ butt weld in a low carbon steel plate, using the Full Matrix Capture technique. Curve-fitting algorithms are also presented that allowautomated focussingthrough the wedge-plate interface. Finally, a description is given on how algorithms may be adapted to allow auto-focussing through dual media with a non-planar interface.},
	urldate = {2012-11-27},
	journal = {NDT \& E International},
	author = {Weston, Miles and Mudge, Peter and Davis, Claire and Peyton, Anthony},
	month = apr,
	year = {2012},
	keywords = {Full Matrix Capture, non-destructive evaluation, Signal processing, Snell's law, ultrasonic imaging},
	pages = {43--50},
	file = {ScienceDirect Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\RT97BTI3\\Weston et al. - 2012 - Time efficient auto-focussing algorithms for ultra.pdf:application/pdf;ScienceDirect Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\JS7ICPXS\\S0963869511001526.html:text/html}
}

@article{oralkan_capacitive_2002,
	title = {Capacitive micromachined ultrasonic transducers: next-generation arrays for acoustic imaging?},
	volume = {49},
	issn = {0885-3010},
	shorttitle = {Capacitive micromachined ultrasonic transducers},
	doi = {10.1109/TUFFC.2002.1049742},
	abstract = {Piezoelectric materials have dominated the ultrasonic transducer technology. Recently, capacitive micromachined ultrasonic transducers (CMUTs) have emerged as an alternative technology offering advantages such as wide bandwidth, ease of fabricating large arrays, and potential for integration with electronics. The aim of this paper is to demonstrate the viability of CMUTs for ultrasound imaging. We present the first pulse-echo phased array B-scan sector images using a 128-element, one-dimensional (1-D) linear CMUT array. We fabricated 64- and 128-element 1-D CMUT arrays with 100\% yield and uniform element response across the arrays. These arrays have been operated in immersion with no failure or degradation in performance over the time. For imaging experiments, we built a resolution test phantom roughly mimicking the attenuation properties of soft tissue. We used a PC-based experimental system, including custom-designed electronic circuits to acquire the complete set of 128/spl times/128 RF A-scans from all transmit-receive element combinations. We obtained the pulse-echo frequency response by analyzing the echo signals from wire targets. These echo signals presented an 80\% fractional bandwidth around 3 MHz, including the effect of attenuation in the propagating medium. We reconstructed the B-scan images with a sector angle of 90 degrees and an image depth of 210 mm through offline processing by using RF beamforming and synthetic phased array approaches. The measured 6-dB lateral and axial resolutions at 135 mm depth were 0.0144 radians and 0.3 mm, respectively. The electronic noise floor of the image was more than 50 dB below the maximum mainlobe magnitude. We also performed preliminary investigations on the effects of crosstalk among array elements on the image quality. In the near field, some artifacts were observable extending out from the array to a depth of 2 cm. A tail also was observed in the point spread function (PSF) in the axial direction, indicating the - - existence of crosstalk. The relative amplitude of this tail with respect to the mainlobe was less than -20 dB.},
	number = {11},
	journal = {IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control},
	author = {Oralkan, O. and Ergun, A.S. and Johnson, J.A. and Karaman, Mustafa and Demirci, U. and Kaviani, K. and Lee, T.H. and Khuri-Yakub, B.T.},
	month = nov,
	year = {2002},
	keywords = {Acoustic arrays, acoustic imaging, Adipose Tissue, Algorithms, Artifacts, A-scan image, Attenuation, attenuation properties, Bandwidth, biological tissues, biomedical transducers, biomedical ultrasonics, B-scan image, capacitive micromachined ultrasonic transducer, capacitive sensors, Computer Simulation, crosstalk, Electric Capacitance, Electrodes, electronic noise, Equipment Design, Image Enhancement, image reconstruction, Liver, micromachining, Miniaturization, one-dimensional linear array, phantom, phantoms, Phantoms, Imaging, Phased arrays, point spread function, pulse-echo frequency response, Quality Control, Radio frequency, RF beamforming, Sensitivity and Specificity, Signal Processing, Computer-Assisted, soft tissue, Stochastic Processes, synthetic phased array, Transducers, ultrasonic imaging, ultrasonic transducer arrays, Ultrasonic transducers, Ultrasonography},
	pages = {1596--1610},
	file = {IEEE Xplore Abstract Record:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\6F7ITRQA\\articleDetails.html:text/html;IEEE Xplore Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\JMADVU4T\\Oralkan et al. - 2002 - Capacitive micromachined ultrasonic transducers n.pdf:application/pdf}
}

@book{schuster_introduction_1904,
	title = {An introduction to the theory of optics},
	url = {http://archive.org/details/theoryoptics00schurich},
	language = {eng},
	urldate = {2012-11-27},
	publisher = {London, E. Arnold},
	author = {Schuster, Arthur},
	collaborator = {{University of California Libraries}},
	year = {1904},
	keywords = {Physical optics}
}

@article{humeida_simulation_2013,
	title = {Simulation of ultrasonic array imaging of composite materials with defects},
	volume = {60},
	issn = {0885-3010},
	doi = {10.1109/TUFFC.2013.2778},
	abstract = {Ultrasonic transducer arrays are extensively used for the nondestructive evaluation of materials for aerospace and other applications. However, their use with composites requires some technique development because of reflections at the layer boundaries and the effects of attenuation. When used in full matrix capture mode, algorithms such as the total focusing method (TFM) must be applied to obtain the image. In composite materials, improvement to the algorithm is required to include the effects of material anisotropy (affecting wave speed) and optimum aperture limits to optimize the signal-to-noise ratio and location detection for a defect in the material. This paper presents simulations of the ultrasonic array signals in multilayer anisotropic materials with and without a simulated defect. A kernel model for plane wave propagation in the material is combined with an angular spectrum decomposition (for finite transducer elements) and transducer frequency response, to model the full array signals. Inclusion of the defect is through its far-field scattering response. The model facilitates the study of imaging algorithm development by identification of the effects of anisotropy, signal-to-noise ratio, and aperture limit. An analytical method for the calculation of the effective group velocity in the composite at low frequency is demonstrated, permitting rapid calculation of time delay laws in practice.},
	number = {9},
	journal = {IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control},
	author = {Humeida, Y. and Pinfield, V.J. and Challis, R.E. and Wilcox, P.D. and Li, Chuan},
	month = sep,
	year = {2013},
	keywords = {Acoustics, acoustic signal processing, aerospace applications, angular spectrum decomposition, Arrays, Attenuation, composite materials, defect detection, defective composite materials, delays, effective group velocity, far-field scattering, Finite element analysis, finite transducer elements, frequency response, full array signals, full matrix capture mode, kernel model, layer boundaries, location detection, Mathematical model, multilayer anisotropic materials, multilayers, nondestructive evaluation, Nonhomogeneous media, optimization, optimum aperture limits, plane wave propagation, reflections, signal-to-noise ratio, simulated defect, Stress, TFM, time delay laws, total focusing method, transducer frequency response, Transducers, ultrasonic array imaging, ultrasonic array signals, ultrasonic focusing, ultrasonic imaging, ultrasonic materials testing, ultrasonic propagation, ultrasonic reflection, ultrasonic scattering, ultrasonic transducer arrays, ultrasonic velocity, wave speed},
	pages = {1935--1948},
	file = {IEEE Xplore Abstract Record:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\9UQEA9JC\\articleDetails.html:text/html;IEEE Xplore Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\NR5VB25D\\Humeida et al. - 2013 - Simulation of ultrasonic array imaging of composit.pdf:application/pdf}
}

@article{sakhaei_optimization_2006,
	title = {Optimization of point spread function in ultrasound arrays},
	volume = {44},
	issn = {0041-624X},
	doi = {10.1016/j.ultras.2005.10.002},
	abstract = {The design of aperture weightings in ultrasound arrays is a multi-objective optimization problem, involving parameters such as delays, aperture size, focal depth, operating frequency and beam properties. Besides, apodization causes the SNR in array output to be decreased. We introduce an analytic expression of the lateral point spread function and a model for SNR as nonlinear functions of weights, based on which, a new aperture design method is established, resulting in an optimal set of weights. These weights provide a point spread function having the predetermined peak sidelobe level, while the SNR in array output is optimized. Optimization results from a linear array with M=128 elements equally spaced at one wavelength, center frequency f0=3.5 MHz and 50\% relative bandwidth, have shown that decreasing the peak sidelobe level, decreases the SNR. Therefore, an array designer can select a proper set of weights according to its application, using a SNR curve versus to the peak sidelobe level. In addition, the method can maintain the same beam properties over a long range with low variations in the SNR. Simulation results have shown only 1 dB variations in the SNR for depths from 20 mm to 120 mm, which is a longer range and better SNR performance than the conventional methods.},
	language = {eng},
	number = {2},
	journal = {Ultrasonics},
	author = {Sakhaei, M and Mahloojifar, A and Malek, A},
	month = feb,
	year = {2006},
	pmid = {16321415},
	pages = {159--165}
}

@book{halmshaw_non-destructive_1991,
	address = {London},
	title = {Non-destructive testing},
	isbn = {0-340-54521-6 978-0-340-54521-8},
	language = {English},
	publisher = {E. Arnold},
	author = {Halmshaw, R},
	year = {1991}
}

@article{wang_mvdr-based_2009,
	title = {{MVDR}-based coherence weighting for high-frame-rate adaptive imaging},
	volume = {56},
	issn = {0885-3010},
	doi = {10.1109/TUFFC.2009.1293},
	abstract = {Some success has been demonstrated in the extensive studies of adaptive imaging, but these approaches are generally not suitable for high-frame-rate (HFR) imaging where broad transmit beams are required. In this study, we propose an effective adaptive imaging method suitable for HFR imaging based on coherence-factor (CF) weighting and the minimum-variance-distortionless-response (MVDR) method. The CF is an index of focusing quality estimated from receive-channel data in which the amplitude of each image pixel is weighted by the corresponding CF so as to reduce the unwanted sidelobes. Direct implementation of CF weighting in HFR imaging does not provide satisfactory results because the broad transmit beams required for HFR imaging reduce the accuracy of CF calculations. In this study, we alleviated this problem by applying the MVDR method. We test the proposed method with the synthetic transmit aperture method where only 8 firings are required to form an image. Both simulations and clinical breast imaging data were used, and the proposed method enhanced the mean contrast by around 4.6 dB and the mean contrast-to-noise ratio by around 20\%. The results demonstrate that the proposed method is effective at improving the image quality.},
	number = {10},
	journal = {IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control},
	author = {Wang, Shun-Li and Li, Pai-Chi},
	month = oct,
	year = {2009},
	keywords = {Accuracy, adaptive signal processing, Adult, Aged, Algorithms, Amplitude estimation, biological organs, biomedical ultrasonics, Breast, Breast Neoplasms, clinical breast imaging data, Computer Simulation, Focusing, gynaecology, high-frame-rate adaptive imaging, Humans, image quality, index-of-focusing quality, medical image processing, Middle Aged, minimum variance distortionless response, MVDR-based coherence weighting, Phantoms, Imaging, Pixel, receive-channel data, Signal Processing, Computer-Assisted, synthetic transmit aperture method, Testing, Transducers, ultrasonic focusing, Ultrasonography, Mammary},
	pages = {2097--2110},
	file = {IEEE Xplore Abstract Record:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\7CRNKATM\\abs_all.html:text/html;IEEE Xplore Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\TJDKG7PM\\Wang and Li - 2009 - MVDR-based coherence weighting for high-frame-rate.pdf:application/pdf}
}

@article{lane_inspection_2010,
	title = {The inspection of anisotropic single-crystal components using a 2-{D} ultrasonic array},
	volume = {57},
	issn = {0885-3010},
	doi = {10.1109/TUFFC.2010.1748},
	abstract = {Single-crystal metal alloys are used extensively in the manufacture of jet engine components for their excellent mechanical properties at elevated temperatures. The inspection of these components using 2-D ultrasonic arrays potentially allows the detection of subsurface defects in three-dimensions from one inspection location. Such methods are not currently suitable for the inspection of single-crystal components because the high elastic anisotropy of single-crystal materials causes directional variation in ultrasonic waves. In this paper, a model of wave propagation in anisotropic material is used to correct an ultrasonic imaging algorithm and is applied to a single-crystal test specimen. For this corrected-algorithm, the orientation of the crystal in a specimen must be known before the inspection. Using the same ultrasonic array to measure the orientation and perform the defect inspection offers the most practical solution. Therefore, potential crystallographic orientation methods using 2-D ultrasonic arrays are also developed and evaluated.},
	number = {12},
	journal = {IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control},
	author = {Lane, C.J.L. and Dunhill, A. K. and Drinkwater, B.W. and Wilcox, P.D.},
	month = dec,
	year = {2010},
	keywords = {2-D ultrasonic array, Anisotropic magnetoresistance, anisotropic single-crystal components, Arrays, crystallographic orientation method, crystal orientation, Crystals, inspection, Mathematical model, Two dimensional displays, ultrasonic imaging, ultrasonic imaging algorithm, ultrasonic materials testing, ultrasonic propagation, wave propagation},
	pages = {2742--2752},
	file = {IEEE Xplore Abstract Record:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\UIXGNFSW\\articleDetails.html:text/html;IEEE Xplore Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\CXBVZ4RP\\Lane et al. - 2010 - The inspection of anisotropic single-crystal compo.pdf:application/pdf}
}

@article{flax_phase-aberration_1988,
	title = {Phase-aberration correction using signals from point reflectors and diffuse scatterers: basic principles},
	volume = {35},
	issn = {0885-3010},
	shorttitle = {Phase-aberration correction using signals from point reflectors and diffuse scatterers},
	doi = {10.1109/58.9333},
	abstract = {Methods for correction of phase aberrations induced by near-field variations in the index of refraction are explored. Using signals obtained from a sampled aperture (i.e. transducer array), phase aberrations can be accurately measured with a correlation approach similar to methods used in adaptive optics and radar. However, the method presented here has no need for a beacon or an ideal point reflector to act as a source for estimating phase errors. It uses signals from random collections of scatterers to determine phase aberrations accurately. Because there is no longer a need for a beacon signal, the method is directly applicable not only to medical ultrasound imaging but also to any coherent imaging system with a sampled aperture, such as radar and sonar.{\textless}{\textgreater}},
	number = {6},
	journal = {IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control},
	author = {Flax, S.W. and O'Donnell, M.},
	month = nov,
	year = {1988},
	keywords = {acoustic imaging, acoustic signal processing, Adaptive arrays, adaptive optics, correlation, diffuse scatterers, index of refraction, Medical ultrasound imaging, near-field variations, Optical arrays, Optical imaging, Optical refraction, phase aberrations, Phased arrays, Phase measurement, point reflectors, radar, Radar measurements, sampled aperture, transducer array, Transducers, ultrasonic imaging},
	pages = {758--767},
	file = {IEEE Xplore Abstract Record:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\SAJEGXAE\\abs_all.html:text/html;IEEE Xplore Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\MKWBXEE4\\Flax and O'Donnell - 1988 - Phase-aberration correction using signals from poi.pdf:application/pdf}
}

@inproceedings{kitze_saft-reconstruction_2012,
	title = {Saft-reconstruction in ultrasonic immersion technique using phased array transducers},
	volume = {1430},
	isbn = {0094-243X},
	url = {http://adsabs.harvard.edu/abs/2012AIPC.1430..825K},
	doi = {10.1063/1.4716310},
	abstract = {The two main preconditions for the application of the Synthetic Aperture 
Focusing Technique (SAFT) are: (i) a large divergence of the sound beam
of the transducer and (ii) an exact knowledge about the sound
propagation path. These requirements are easily fulfilled for point
sources directly mounted on the surface of the specimen. In many cases,
however, the transducer is wedge mounted and/or coupled using a water
delay line, e.g. in immersion technique. These delay lines change the
beam index and the propagation path has to be evaluated for each pixel
separately considering Fermat's principle. Using phased array
transducers, a sector scan can improve the divergence of the sound beam.
The introduced method combines the advantages of using a phased array
transducer in immersion technique to improve SAFT reconstruction. An
algorithm is presented accounting the influence of the delay line on the
reconstruction method. The applicability of the algorithm is shown by
validation with simulated echo responses and with experimental results
collected from a specimen with artificial flaws.},
	urldate = {2014-10-02},
	booktitle = {Review of {Progress} in {Quantitative} {Nondestructive} {Evaluation}},
	author = {Kitze, J. and Prager, J. and Boehm, R. and Völz, U. and Montag, H.-J.},
	month = may,
	year = {2012},
	keywords = {acoustical devices for the generation and reproduction of sound, acoustic signal processing, acoustic wave propagation, Signal processing instrumentation integrated systems smart transducers devices and architectures displays and interfaces for acoustic systems, Transduction, Ultrasonics, Ultrasonics quantum acoustics and physical effects of sound, Ultrasonic transducers},
	pages = {825--832}
}

@inproceedings{synnevag_minimum_2005,
	title = {Minimum variance adaptive beamforming applied to medical ultrasound imaging},
	volume = {2},
	doi = {10.1109/ULTSYM.2005.1603066},
	booktitle = {2005 {IEEE} {Ultrasonics} {Symposium}},
	author = {Synnevåg, J.-F. and Austeng, A. and Holm, S.},
	month = sep,
	year = {2005},
	keywords = {array signal processing, Biomedical imaging, Covariance matrix, Delay, Focusing, Medical simulation, Narrowband, Radio frequency, ultrasonic imaging, Wire},
	pages = {1199--1202},
	file = {IEEE Xplore Abstract Record:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\FKTQZZZZ\\abs_all.html:text/html;IEEE Xplore Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\IMCIUHRT\\Synnevåg et al. - 2005 - Minimum variance adaptive beamforming applied to m.pdf:application/pdf}
}

@inproceedings{fritsch_new_2012,
	title = {A new technique for fast dynamic focusing law computing},
	volume = {1433},
	url = {http://scitation.aip.org/content/aip/proceeding/aipcp/10.1063/1.3703162},
	doi = {10.1063/1.3703162},
	abstract = {Dynamic focusing requires computing the individual delays for every element and every focus in the image. This is an easy and relatively fast task if the inspected medium is homogeneous. Nevertheless, some difficulties arise in presence of interfaces (i.e, wedges, immersion, etc.): refraction effects require computing the Snell\'s law for every focus and element to find the fastest ray entry point in the interface. The process is easy but takes a long time. This work presents a new technique to compute the focusing delays for an equivalent virtual array that operates in the second medium only, thus avoiding any interface. It is nearly as fast as computing the focal laws in the homogeneous case and an order of magnitude faster than Snell\'s or Fermat\'s principle based methods. Furthermore, the technique is completely general and can be applied to any equipment having dynamic focusing capabilities. In fact, the technique is especially well suited for real-time focal law computing hardware.},
	urldate = {2014-10-02},
	booktitle = {{AIP} {Conference} {Proceedings}},
	publisher = {AIP Publishing},
	author = {Fritsch, C. and Cruza, J. F. and Brizuela, J. and Camacho, J. and Moreno, J. M.},
	month = may,
	year = {2012},
	keywords = {Acoustic wave refraction, Computer hardware, Optical refraction},
	pages = {165--168},
	file = {Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\MTMWUKXD\\1.html:text/html}
}

@inproceedings{tweedie_total_2007,
	title = {Total {Focussing} {Method} for {Volumetric} {Imaging} in {Immersion} {Non} {Destructive} {Evaluation}},
	doi = {10.1109/ULTSYM.2007.259},
	abstract = {This paper describes the use of a 550 (25times22) element 2 MHz 2D piezoelectric composite array in immersion mode to image an aluminum test block containing a collection of artificial defects. The defects included a 1 mm diameter side-drilled hole, a collection of 1 mm slot defects with varying degrees of skew to the normal and a flat bottomed hole. The data collection was carried out using the full matrix capture; a scanning procedure was developed to allow the operation of the large element count array through a conventional 64-channel phased array controller. A 3D TFM algorithm capable of imaging in a dual media environment was implemented in MATLAB for the offline processing the raw scan data. This algorithm facilitates the creation of 3D images of defects while accounting for refraction effects at material boundaries. In each of the test samples interrogated the defects, and their spatial position, are readily identified using TFM. Defect directional information has been characterized using VTFM for defect exhibiting angles up to and including 45deg of skew.},
	booktitle = {{IEEE} {Ultrasonics} {Symposium}, 2007},
	author = {Tweedie, A and O'Leary, R.L. and Harvey, G. and Gachagan, A and Holmes, C. and Wilcox, P.D. and Drinkwater, B.W.},
	month = oct,
	year = {2007},
	keywords = {2D piezoelectric composite array, 3D image creation, 3D TFM algorithm, acoustic signal processing, Al, aluminium, Aluminum, aluminum test block imaging, array signal processing, artificial defects imaging, Biomedical signal processing, composite materials, conventional 64-channel phased array controller, defect information characterization, dual media environment, flaw detection, Focusing, frequency 2 MHz, full matrix capture scanning procedure, image processing, immersion non destructive evaluation, large element count array, mathematics computing, MATLAB, Mechanical engineering, Phased arrays, piezoelectric materials, raw scan data offline processing, refraction effects, side-drilled holes, Signal processing algorithms, size 1 mm, slot defects, Testing, total focussing method, ultrasonic imaging, ultrasonic materials testing, vectors, vectorTFM, volumetric imaging},
	pages = {1017--1020},
	file = {IEEE Xplore Abstract Record:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\PWIK5C7Z\\articleDetails.html:text/html;IEEE Xplore Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\MBXTNKDW\\Tweedie et al. - 2007 - 11D-2 Total Focussing Method for Volumetric Imagin.pdf:application/pdf}
}

@article{zhang_defect_2010,
	title = {Defect detection using ultrasonic arrays: {The} multi-mode total focusing method},
	volume = {43},
	issn = {0963-8695},
	shorttitle = {Defect detection using ultrasonic arrays},
	url = {http://www.sciencedirect.com/science/article/pii/S0963869509001480},
	doi = {10.1016/j.ndteint.2009.10.001},
	abstract = {Ultrasonic arrays allow a given scatterer to be illuminated from a wide range of angles and hence are capable of extracting significant information about the scatterer. In this paper a general imaging methodology, termed multi-mode total focusing method, is proposed in which any combination of modes and reflections can be used to produce an image of the test structure. Like the total focusing method, this approach is implemented by post-processing the full matrix of array data to achieve a synthetic focus at every pixel in the image. A hybrid model is used to predict the array data and demonstrate the performance of the multi-mode imaging concept. This hybrid model combines far field scattering coefficient matrices with a ray-based wave propagation model. This allows the inclusion of longitudinal waves, shear waves and wave mode conversions. It is shown that, with prior knowledge of likely scatterer location and orientation, the mode combination and array location can be optimised to maximise the performance of array inspections. A practically relevant weld inspection application is then described and its optimisation is discussed.},
	number = {2},
	urldate = {2014-10-02},
	journal = {NDT \& E International},
	author = {Zhang, Jie and Drinkwater, Bruce W. and Wilcox, Paul D. and Hunter, Alan J.},
	month = mar,
	year = {2010},
	keywords = {Non-destructive testing, Scattering coefficient matrix, Ultrasonic arrays},
	pages = {123--133},
	file = {ScienceDirect Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\FP2SVWCV\\Zhang et al. - 2010 - Defect detection using ultrasonic arrays The mult.pdf:application/pdf;ScienceDirect Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\8GVIA7GF\\S0963869509001480.html:text/html}
}

@inproceedings{matuda_imaging_2012,
	title = {Imaging through a convex interface with unknown position and shape using an ultrasonic linear array},
	volume = {1433},
	url = {http://scitation.aip.org/content/aip/proceeding/aipcp/10.1063/1.3703165},
	doi = {10.1063/1.3703165},
	abstract = {This paper presents a technique for improving the internal imaging of a solid object immersed in water using an ultrasonic array. This technique consists in determining the position and shape of a convex object surface using a combination of synthetic transmit aperture (STA) and sign coherence factor (SCF) methods. The SCF attenuates the grating lobe noise. The technique is applied to a cylindrical aluminium object with internal holes simulating defects. The first step is the acquisition of a sequence of STA images with SCF, using a distinct group of adjacent array elements for each image. In the second step, a circle is fitted to the positions of the peak values in each image. Finally, using the Fermat\'s principle and this circle as the interface between the water and the metallic object, the propagation delays from the array elements to the image grid points may be calculated and used in another STA image. In this final image, the small holes in the cylindrical object can clearly be identified. The effects of the SCF for a large diameter circular reflector are simulated and compared with experimental data.},
	urldate = {2014-10-02},
	booktitle = {{AIP} {Conference} {Proceedings}},
	publisher = {AIP Publishing},
	author = {Matuda, Marcelo Y. and Buiochi, Flávio and Adamowski, Julio C.},
	month = may,
	year = {2012},
	keywords = {aluminium, Coherence, Diffraction gratings, Ultrasonics, Ultrasonography},
	pages = {177--180},
	file = {Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\UGWFX265\\1.html:text/html}
}

@article{dziewierz_computationally_2013,
	title = {Computationally efficient solution of snell's law of refraction},
	volume = {60},
	issn = {0885-3010},
	shorttitle = {Correspondence},
	doi = {10.1109/TUFFC.2013.2689},
	abstract = {An algorithm for an efficient parallel implementation of Snell's law of refraction, applicable to planar interfaces, is found by algebraic manipulation. The algorithm is tailored for general-purpose graphics processing unit (GP-GPU)-type processors. Numerical singularity in the solution is addressed. Performance is compared against other implementations. Application areas include real-time total focusing method implementation, phased-array probe computer-aided design (CAD), and data fusion.},
	number = {6},
	journal = {IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control},
	author = {Dziewierz, J. and Gachagan, A},
	month = jun,
	year = {2013},
	keywords = {algebraic manipulation, computationally efficient solution, data fusion, general-purpose graphics processing unit, graphics processing units, parallel implementation, planar interfaces, real-time total focusing method implementation, sensor fusion, Snell law of refraction, ultrasonic devices},
	pages = {1256--1259},
	file = {IEEE Xplore Abstract Record:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\H2EEK9ZI\\articleDetails.html:text/html;IEEE Xplore Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\4U9P8TK8\\Dziewierz and Gachagan - 2013 - Correspondence Computationally efficient solution.pdf:application/pdf}
}

@book{jones_acoustical_2012,
	title = {Acoustical {Imaging}},
	isbn = {978-1-4615-1943-0},
	abstract = {This volume represents the proceedings of the 21 st International Symposium on Acoustical Imaging, which was held at the Surf and Sand Hotel in Laguna Beach, California, March 28-30, 1994. These unique and highly interdisciplinary series of symposiums have met at intervals of roughly 18 months over the past 30 some years. In general these meetings are devoted to all aspects and all fields of imaging that use acoustics. The meetings are usually small, with 100 to 200 participants, and stimulate useful interchanges across disciplines. These are the only regular meetings where the major researchers in all areas of acoustical imaging can come together to interchange ideas and new concepts. The Acoustical Imaging Symposiums have long been regarded as the premier meeting of this type in the general field of acoustics. The highly regarded and carefully edited proceedings have been published regularly by Plenum Press. I am proud and honored to serve as editor of the 21st volume in this series. The 21st Symposium was attended by well over 100 participants from some 18 countries. During the three day symposium, 94 scientific presentations were given, 66 as formal lectures and 28 in a poster format. Sufficient time was available during the conference, both following the presentations and informally during meals and breaks, for active discussions among all participants. Over 80 of the presentations have been selected for inclusion in these proceedings.},
	language = {en},
	publisher = {Springer Science \& Business Media},
	author = {Jones, J. P.},
	month = dec,
	year = {2012},
	keywords = {Science / Acoustics \& Sound, Science / Waves \& Wave Mechanics, Technology \& Engineering / Electrical, Technology \& Engineering / Optics}
}

@article{wagdy_errors_1985,
	title = {Errors in {Sampled} {Data} {Phase} {Measurement}},
	volume = {34},
	issn = {0018-9456},
	doi = {10.1109/TIM.1985.4315392},
	abstract = {Synchronous real-time sampling can be used to measure the phase angle ?? between two sine waves in a relatively low-frequency range. The data samples are acquired by a microcomputer-based system, then manipulated to determine ??. The system uses less hardware than a traditional phase meter, however there will be an error in ?? due to mislocating the zero-crossings of the two sine waves. An error analysis is given, which indicates that errors mainly depend on signal amplitudes, number of quantization bits, and number of samples per cycle. Also, numerical results are illustrated.},
	number = {4},
	journal = {IEEE Transactions on Instrumentation and Measurement},
	author = {Wagdy, Mahmoud Fawzy and Lucas, Michael S.P.},
	month = dec,
	year = {1985},
	keywords = {Distortion measurement, Frequency, Goniometers, Hardware, Instruments, Linear approximation, Phase measurement, Quantization, Sampling methods, Software measurement},
	pages = {507--509},
	file = {IEEE Xplore Abstract Record:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\HMKDUWKV\\abs_all.html:text/html;IEEE Xplore Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\MDG6BDSQ\\Wagdy and Lucas - 1985 - Errors in Sampled Data Phase Measurement.pdf:application/pdf}
}

@article{dallosso_computer_2006,
	title = {Computer algebra systems as mathematical optimizing compilers},
	volume = {59},
	issn = {0167-6423},
	url = {http://www.sciencedirect.com/science/article/pii/S0167642305000808},
	doi = {10.1016/j.scico.2005.06.003},
	abstract = {The role of computer algebra systems (CASs) is not limited to analyzing and solving mathematical and physical problems. They have also been used as tools in the development process of computer programs, starting from the specification and ending with the coding and testing phases. In this way one can exploit their powerful mathematical capacity during the development phases and, by the other way, take advantage of the speed performance of languages such as FORTRAN or C in the implementation. Among the mathematical features of CASs there are transformations allowing one to optimize the final code instructions. In this paper we show some kind of optimizations that can be done on new or existing algorithms, by extending some techniques that compilers apply currently to optimize the machine code. The results show that the CPU time taken by the optimized code is reduced by a factor that can reach 5. The optimizations are performed with a package built on a well known CAS: Mathematica.},
	number = {3},
	urldate = {2014-10-02},
	journal = {Science of Computer Programming},
	author = {Dall’Osso, Aldo},
	month = feb,
	year = {2006},
	keywords = {Code synthesis, Computer algebra systems, Optimizing compilers, Problem-solving environments, Scientific software development},
	pages = {250--273},
	file = {ScienceDirect Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\MISUK7CW\\Dall’Osso - 2006 - Computer algebra systems as mathematical optimizin.pdf:application/pdf;ScienceDirect Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\I9DVGDK2\\S0167642305000808.html:text/html}
}

@article{lines_rapid_2006,
	title = {Rapid distributed data collection with arrays – the next step beyond full waveform capture},
	volume = {48},
	doi = {10.1784/insi.2006.48.2.84},
	abstract = {Ultrasonic C-scanning is widely used for large-area flaw detection but acquiring the full RF waveform for each surface point – Full Waveform Capture (FWC) – offers many advantages. A system that used phased arrays to achieve this without loss of area coverage rate has been reported(1). FWC allows many signal processing operations, previously only possible at acquisition, to be performed off-line. Multiple or time-consuming algorithms can be performed on the same data set without compromising inspection speed but some, such as steering and focusing, must still be performed at acquisition.Although ultrasonic arrays are now widely accepted in imaging systems, their full capability will only be realised when viewed as distributed data collection devices(2). The modular array hardware of DSL’s ‘FlawInspecta’ can now achieve this at real-time rates, significantly extending the post-processing operations that can be performed. These include steering and focusing adjustments, data-dependent adaptive focusing, and multi-array data collection and processing. A flexible data formatting has been devised to provide an interface for end-users to develop customised algorithms.The paper reports on the distributed data acquisition architecture and the data storage format. Specific post processing operations are covered elsewhere(3) but some typical options will be outlined.},
	number = {2},
	journal = {Insight - Non-Destructive Testing and Condition Monitoring},
	author = {Lines, D I A},
	month = feb,
	year = {2006},
	pages = {84--88}
}

@article{zhang_efficient_2014,
	title = {Efficient immersion imaging of components with nonplanar surfaces},
	volume = {61},
	issn = {0885-3010},
	doi = {10.1109/TUFFC.2014.3035},
	abstract = {Ultrasonic array inspection of a component with a nonplanar surface can be achieved in immersion using a liquid layer to couple ultrasonic waves from an array probe into a solid structure. This paper presents an efficient way to compute the appropriate element time delays in immersion without compromising the measurement accuracy. In the proposed imaging process, the surface geometry is first measured ultrasonically by forming an image of the component surface in the couplant. This leads to a set of discrete points that define the surface profile of the component. The propagation time from an array element to a point in the component is then determined by a grid search of candidate ray-paths through each surface point to identify the one that yields the shortest traveling time. Propagation times in the component are first generated on a coarse mesh of points and then these values are linearly interpolated to find the propagation time to each image pixel. The computed propagation times are finally used to reconstruct an image of the component interior. An analytical model is developed to determine a relationship between estimated propagation time errors and their effect on the array inspection in terms of signal amplitude from a reflector. For nominally normal incidence inspection of a metallic component with a minimum surface radius of 30 wavelengths immersed in water, it is found that the surface of the component can be adequately described by points spaced by one wavelength and that delays can be computed on a coarse grid of points spaced at 3 wavelengths. With these parameters, the reduction in amplitude of a point target in the component is shown to be less than 1 dB.},
	number = {8},
	journal = {IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control},
	author = {Zhang, Jie and Drinkwater, B.W. and Wilcox, P.D.},
	month = aug,
	year = {2014},
	keywords = {Acoustics, analytical model, array probe, Arrays, coarse grid of points, coarse mesh, component interior, computed propagation, Delay effects, efficient immersion imaging, element time delays, estimated propagation time errors, image pixel, image reconstruction, Imaging, inspection, interpolation, linear interpolation, liquid layer, metallic component, minimum surface radius, nominal normal incidence inspection, nonplanar surfaces, short traveling time, solid structure, surface geometry, surface point, Surface treatment, Surface waves, ultrasonic array inspection, Ultrasonic arrays, ultrasonic imaging, ultrasonic materials testing, ultrasonic propagation, Ultrasonic waves},
	pages = {1284--1295},
	file = {IEEE Xplore Abstract Record:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\V2E6INXH\\abs_all.html:text/html;IEEE Xplore Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\2DAX96T4\\Zhang et al. - 2014 - Efficient immersion imaging of components with non.pdf:application/pdf}
}

@article{st_clair_electromagnetic_1941,
	title = {An {Electromagnetic} {Sound} {Generator} for {Producing} {Intense} {High} {Frequency} {Sound}},
	volume = {12},
	issn = {0034-6748, 1089-7623},
	url = {http://scitation.aip.org/content/aip/journal/rsi/12/5/10.1063/1.1769874},
	doi = {10.1063/1.1769874},
	number = {5},
	urldate = {2014-10-09},
	journal = {Review of Scientific Instruments},
	author = {St Clair, Hillary W.},
	month = may,
	year = {1941},
	keywords = {Sound generation},
	pages = {250--256},
	file = {Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\A3JJSZ52\\Clair - 1941 - An Electromagnetic Sound Generator for Producing I.pdf:application/pdf;Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\EB82FESI\\1.html:text/html}
}

@book{gooberman_ultrasonics:_1969,
	title = {Ultrasonics: {Theory} and {Application}},
	shorttitle = {Ultrasonics},
	language = {en},
	publisher = {Hart Publishing Company},
	author = {Gooberman, George L.},
	year = {1969},
	keywords = {Ultrasonic waves}
}

@book{transducer_concise_2006,
	address = {Oxford},
	edition = {11th Revised edition edition},
	title = {Concise {Oxford} {English} {Dictionary}: {Eleventh} edition},
	isbn = {978-0-19-929634-7},
	shorttitle = {Concise {Oxford} {English} {Dictionary}},
	abstract = {Based on the authority of the Oxford English Corpus and the ongoing research of Oxford Dictionaries, this revised edition of the Concise Oxford English Dictionary, 11th edition contains over 240,000 words, phrases, and definitions, and provides the most authoritative description of the English language. It offers rich vocabulary coverage, with full treatment of World English, rare, historical, and archaic terms, as well as scientific and technical vocabulary. This revised edition includes hundreds of new and up-to-date words, such as sudoku,  agroterrorism, and bird flu, with a special focus on words and phrases used in business English eg. helicopter view, knowledge economy, and vulture fund. This edition retains such popular features as Word Histories, the Guide to Good English, and appendices on countries of the world, alphabets, and more. New to this edition is a compelling 'English Uncovered' supplement, which presents new findings from the Oxford English Corpus. Find out the most common words in our language, discover which words have the most meanings, and learn about the working of words beneath the surface. For UK only, there is a special promotion which will allow users to use a new SMS service to receive dictionary definitions direct to their mobile phone*. *Terms and conditions apply},
	language = {English},
	publisher = {OUP Oxford},
	author = {Transducer},
	month = jun,
	year = {2006}
}

@book{rosen_signals_2010,
	address = {United Kingdom},
	edition = {2 edition},
	title = {Signals and {Systems} for {Speech} and {Hearing} 2nd edition},
	isbn = {978-1-84855-226-5},
	abstract = {This novel book introduces speech and hearing sciences students to the principles of "signal" and "system" analysis. Beginning with an examination of what signals and systems are, the book develops a thorough background from which many of the most important issues in speech and hearing can be tackled. Numerous illustrationKey Features* The first dedicated text on this subject* Presents techniques for speech and hearing analysis and experiments* Contains minimal mathematics in describing a highly technical field* An introductory text for students in speech, hearing and psychology},
	language = {English},
	publisher = {Emerald Group Publishing Limited},
	author = {Rosen, Stuart and Howell, Peter},
	month = dec,
	year = {2010}
}

@article{ryu_magnetoelectric_2001,
	title = {Magnetoelectric {Properties} in {Piezoelectric} and {Magnetostrictive} {Laminate} {Composites}},
	volume = {40},
	issn = {1347-4065},
	url = {http://iopscience.iop.org/1347-4065/40/8R/4948},
	doi = {10.1143/JJAP.40.4948},
	abstract = {Magnetoelectric laminate composites of piezoelectric-magnetostrictive materials were investigated. The composites were prepared by stacking and bonding Pb(Zr, Ti)O3 (PZT) and Terfenol-D disks. Experimental results indicated that the magnetoelectric voltage coefficient, dE/dH, increased with decreasing thickness and increasing piezoelectric voltage constant (g31) of the PZT layer. We obtained the highest magnetoelectric voltage coefficient of 4.68 V/cm·Oe at room temperature for the sample with high g33 PZT of 0.5 mm in thickness. This value is about 36 times higher than the best reported value.},
	language = {en},
	number = {8R},
	urldate = {2014-10-09},
	journal = {Japanese Journal of Applied Physics},
	author = {Ryu, Jungho and Carazo, Alfredo Vázquez and Uchino, Kenji and Kim, Hyoun-Ee},
	month = aug,
	year = {2001},
	pages = {4948},
	file = {Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\SP5KTC4Q\\Ryu et al. - 2001 - Magnetoelectric Properties in Piezoelectric and Ma.pdf:application/pdf;Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\2USNHC4E\\4948.html:text/html}
}

@article{heydt_acoustical_2000,
	title = {Acoustical performance of an electrostrictive polymer film loudspeaker},
	volume = {107},
	issn = {0001-4966},
	url = {http://scitation.aip.org/content/asa/journal/jasa/107/2/10.1121/1.428266},
	doi = {10.1121/1.428266},
	abstract = {A new type of loudspeaker that generatessound by means of the electrostrictive response of a thin polymer film is described. Electrostrictive polymer film (EPF) loudspeakers are constructed with inexpensive, lightweight materials and have a very low profile. The films are typically silicone and are coated with compliant electrodes to allow large film deformations. Acoustical frequency response measurements from 5×5 cm (planar dimensions) prototype EPF loudspeakers are presented. Measurements of harmonic distortion are also shown, along with results demonstrating reduced harmonic distortion achieved with square-root wave shaping. Applications of EPF loudspeakers include active noise control and general-purpose flat-panel loudspeakers.},
	number = {2},
	urldate = {2014-10-09},
	journal = {The Journal of the Acoustical Society of America},
	author = {Heydt, Richard and Pelrine, Ron and Joseph, Jose and Eckerle, Joseph and Kornbluh, Roy},
	month = feb,
	year = {2000},
	keywords = {Acoustical measurements, Acoustics, Acoustic waves, Loudspeakers, Polymer films},
	pages = {833--839},
	file = {Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\H2CXXCPW\\Heydt et al. - 2000 - Acoustical performance of an electrostrictive poly.pdf:application/pdf;Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\78SZ5T52\\1.html:text/html}
}

@article{wright_studies_1994,
	title = {Studies of laser‐generated ultrasound using a micromachined silicon electrostatic transducer in air},
	volume = {95},
	issn = {0001-4966},
	url = {http://scitation.aip.org/content/asa/journal/jasa/95/5/10.1121/1.409826},
	doi = {10.1121/1.409826},
	abstract = {An air‐coupled micromachined siliconelectrostatic transducer has been used to detect ultrasound generated by a pulsed laser in metals and polymers. Bulk longitudinal and shear wave modes have been observed, as have Rayleigh waves in thick samples and Lamb waves in thinner plates. The results are in good agreement with surface displacement waveforms obtained using a contact capacitance device as a reference. The result is a flexible noncontact ultrasonic system with potential uses in materials characterization.},
	number = {5},
	urldate = {2014-10-09},
	journal = {The Journal of the Acoustical Society of America},
	author = {Wright, William M. D. and Schindel, David W. and Hutchins, David A.},
	month = may,
	year = {1994},
	keywords = {Capacitance, Electrostatic transducers, Silicon, Surface acoustic waves, Ultrasonics},
	pages = {2567--2575},
	file = {Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\TRV8NFB2\\Wright et al. - 1994 - Studies of laser‐generated ultrasound using a micr.pdf:application/pdf;Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\KIMJK7IG\\1.html:text/html}
}

@article{thurstone_ultrasonic_1965,
	title = {Ultrasonic {Scanning} of {Biologic} {Tissue} by a {New} {Technique}},
	volume = {149},
	issn = {0036-8075},
	doi = {10.1126/science.149.3681.302},
	abstract = {The size of the ultrasonic beam and beam dispersion severely limit resolution by two-dimensional scanning systems. Resoluti and tissue penetration are improved by using a highly focused, ultrasonic transducer array in conjunction with an electronic timing system for the selection of particular echo information.},
	language = {eng},
	number = {3681},
	journal = {Science (New York, N.Y.)},
	author = {Thurstone, F. L. and Kjosnes, N. I. and McKinney, W. M.},
	month = jul,
	year = {1965},
	pmid = {17838102},
	pages = {302--303}
}

@article{buddemeyer_physics_1975,
	title = {Physics of {Diagnostic} {Ultrasound}},
	volume = {13},
	issn = {0033-8389},
	language = {English},
	number = {3},
	journal = {Radiologic Clinics of North America},
	author = {Buddemeyer, Eu},
	year = {1975},
	pages = {391--402}
}

@article{lazaro_influence_2002,
	title = {Influence of thresholding procedures in ultrasonic grain noise reduction using wavelets},
	volume = {40},
	issn = {0041-624X},
	doi = {10.1016/S0041-624X(02)00149-X},
	abstract = {Wavelet transform based techniques are used for signal-to-noise ratio (SNR) enhancement in ultrasonic non-destructive testing and evaluation of strong sound scattering materials. The overall denoising performance of a wavelet signal processor is conditioned by several processing parameters, including the type of wavelet, thresholding method, and threshold selection rules. Different thresholding procedures and threshold selection rules are analysed in this paper using the discrete wavelet transform and decomposition level dependent thresholds. Global performance is evaluated by means of the SNR enhancement using synthetic grain noise registers with an incrusted flaw signal, with different values of the input SNR, and experimental ultrasonic traces acquired from a carbon fibre reinforced plastic composite block. (C) 2002 Elsevier Science B.V. All rights reserved.},
	language = {English},
	number = {1-8},
	journal = {Ultrasonics},
	author = {Lazaro, J. C. and San Emeterio, J. L. and Ramos, A. and Fernandez-Marron, J. L.},
	month = may,
	year = {2002},
	keywords = {flaw detection, grain noise reduction, NDT, shrinkage, ultrasound, wavelet transform},
	pages = {263--267}
}

@article{alleyne_optimization_1992,
	title = {Optimization of lamb wave inspection techniques},
	volume = {25},
	issn = {0963-8695},
	url = {http://www.sciencedirect.com/science/article/pii/096386959290003Y},
	doi = {10.1016/0963-8695(92)90003-Y},
	abstract = {Lamb waves can propagate over long distances which means that they are attractive for the quick, long range inspection of large structures, and they can also be useful for localized inspection, particularly in thin structures. This paper discusses the selection of the appropriate mode and frequency range for different inspection requirements and reviews the possible methods of excitation, response measurement and signal processing. It is usually desirable to transmit a single, non-dispersive mode, and excitation methods to achieve this are discussed. A variety of signal processing techniques from simple time domain to relatively complex two-dimensional Fourier analysis are available. Time domain processing can often be applied satisfactorily in low frequency-thickness regions where only two modes can propagate, but tends to be unreliable above the cut-off frequency of the a1 mode. As an example of the design of a Lamb wave testing regime, a set of tests on a butt-welded steel plate with simulated weld defects of different depths is described. It is shown that by operating below the a1 cut-off frequency with judicious selection of testing technique, the presence of defects can be detected reliably from changes in the shape of the received waveform.},
	number = {1},
	urldate = {2014-10-09},
	journal = {NDT \& E International},
	author = {Alleyne, David N. and Cawley, Peter},
	year = {1992},
	keywords = {Lamb waves, Signal processing, ultrasonic testing},
	pages = {11--22},
	file = {ScienceDirect Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\MKZIIFIA\\Alleyne and Cawley - 1992 - Optimization of lamb wave inspection techniques.pdf:application/pdf;ScienceDirect Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\3SDVIKKM\\096386959290003Y.html:text/html}
}

@article{santodomingo-rubido_new_2002,
	title = {A new non-contact optical device for ocular biometry},
	volume = {86},
	issn = {, 1468-2079},
	url = {http://bjo.bmj.com/content/86/4/458},
	doi = {10.1136/bjo.86.4.458},
	abstract = {Background: A new commercially available device (IOLMaster, Zeiss Instruments) provides high resolution non-contact measurements of axial length (using partial coherent interferometry), anterior chamber depth, and corneal radius (using image analysis). The study evaluates the validity and repeatability of these measurements and compares the findings with those obtained from instrumentation currently used in clinical practice.
Method: Measurements were taken on 52 subjects (104 eyes) aged 18–40 years with a range of mean spherical refractive error from +7.0 D to −9.50 D. IOLMaster measurements of anterior chamber depth and axial length were compared with A-scan applanation ultrasonography (Storz Omega) and those for corneal radius with a Javal-Schiötz keratometer (Topcon) and an EyeSys corneal videokeratoscope.
Results: Axial length: the difference between IOLMaster and ultrasound measures was insignificant (0.02 (SD 0.32) mm, p = 0.47) with no bias across the range sampled (22.40–27.99 mm). Anterior chamber depth: significantly shorter depths than ultrasound were found with the IOLMaster (−0.06 (0.25) mm, p {\textless}0.02) with no bias across the range sampled (2.85–4.40 mm). Corneal radius: IOLMaster measurements matched more closely those of the keratometer than those of the videokeratoscope (mean difference −0.03 v −0.06 mm respectively), but were more variable (95\% confidence 0.13 v 0.07 mm). The repeatability of all the above IOLMaster biometric measures was found to be of a high order with no significant bias across the measurement ranges sampled.
Conclusions: The validity and repeatability of measurements provided by the IOLMaster will augment future studies in ocular biometry.},
	language = {en},
	number = {4},
	urldate = {2014-10-09},
	journal = {British Journal of Ophthalmology},
	author = {Santodomingo-Rubido, J. and Mallen, E. a. H. and Gilmartin, B. and Wolffsohn, J. S.},
	month = apr,
	year = {2002},
	pmid = {11914218},
	keywords = {anterior chamber depth, axial length, corneal curvature, partial coherence interferometry},
	pages = {458--462},
	file = {Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\T846CKCM\\Santodomingo-Rubido et al. - 2002 - A new non-contact optical device for ocular biomet.pdf:application/pdf;Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\5CHQF2EH\\458.html:text/html}
}

@article{van_pamel_methodology_2014,
	title = {A methodology for evaluating detection performance of ultrasonic array imaging algorithms for coarse-grained materials},
	volume = {61},
	issn = {0885-3010},
	doi = {10.1109/TUFFC.2014.006429},
	abstract = {Improving the ultrasound inspection capability for coarse-grained metals remains of longstanding interest and is expected to become increasingly important for next-generation electricity power plants. Conventional ultrasonic A-, B-, and C-scans have been found to suffer from strong background noise caused by grain scattering, which can severely limit the detection of defects. However, in recent years, array probes and full matrix capture (FMC) imaging algorithms have unlocked exciting possibilities for improvements. To improve and compare these algorithms, we must rely on robust methodologies to quantify their performance. This article proposes such a methodology to evaluate the detection performance of imaging algorithms. For illustration, the methodology is applied to some example data using three FMC imaging algorithms; total focusing method (TFM), phase-coherent imaging (PCI), and decomposition of the time-reversal operator with multiple scattering filter (DORT MSF). However, it is important to note that this is solely to illustrate the methodology; this article does not attempt the broader investigation of different cases that would be needed to compare the performance of these algorithms in general. The methodology considers the statistics of detection, presenting the detection performance as probability of detection (POD) and probability of false alarm (PFA). A test sample of coarse-grained nickel super alloy, manufactured to represent materials used for future power plant components and containing some simple artificial defects, is used to illustrate the method on the candidate algorithms. The data are captured in pulse-echo mode using 64-element array probes at center frequencies of 1 and 5 MHz. In this particular case, it turns out that all three algorithms are shown to perform very similarly when comparing their flaw detection capabilities.},
	number = {12},
	journal = {IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control},
	author = {Van Pamel, A. and Brett, C.R. and Lowe, M.J.S.},
	month = dec,
	year = {2014},
	keywords = {64-element array probes, Acoustics, Arrays, coarse-grained materials, detection performance, detection probability, detection statistics, false alarm probability, flaw detection, FMC imaging algorithms, frequency 1 MHz, frequency 5 MHz, full matrix capture imaging algorithms, granular materials, Imaging, inspection, Materials, multiple scattering filter, nickel alloys, nickel superalloy, noise, phase-coherent imaging, pulse-echo mode, Scattering, superalloys, time-reversal operator decomposition, total focusing method, ultrasonic array imaging algorithms, ultrasonic materials testing, ultrasound inspection capability},
	pages = {2042--2053},
	file = {IEEE Xplore Abstract Record:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\J8I6CI72\\abs_all.html:text/html;IEEE Xplore Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\E3SUJ2B3\\Van Pamel et al. - 2014 - A methodology for evaluating detection performance.pdf:application/pdf}
}

@article{lee_cuda_2012,
	title = {{CUDA} optimization strategies for compute- and memory-bound neuroimaging algorithms},
	volume = {106},
	issn = {0169-2607},
	url = {http://www.sciencedirect.com/science/article/pii/S0169260710002750},
	doi = {10.1016/j.cmpb.2010.10.013},
	abstract = {As neuroimaging algorithms and technology continue to grow faster than CPU performance in complexity and image resolution, data-parallel computing methods will be increasingly important. The high performance, data-parallel architecture of modern graphical processing units (GPUs) can reduce computational times by orders of magnitude. However, its massively threaded architecture introduces challenges when GPU resources are exceeded. This paper presents optimization strategies for compute- and memory-bound algorithms for the CUDA architecture. For compute-bound algorithms, the registers are reduced through variable reuse via shared memory and the data throughput is increased through heavier thread workloads and maximizing the thread configuration for a single thread block per multiprocessor. For memory-bound algorithms, fitting the data into the fast but limited GPU resources is achieved through reorganizing the data into self-contained structures and employing a multi-pass approach. Memory latencies are reduced by selecting memory resources whose cache performance are optimized for the algorithm's access patterns. We demonstrate the strategies on two computationally expensive algorithms and achieve optimized GPU implementations that perform up to 6× faster than unoptimized ones. Compared to CPU implementations, we achieve peak GPU speedups of 129× for the 3D unbiased nonlinear image registration technique and 93× for the non-local means surface denoising algorithm.},
	number = {3},
	urldate = {2016-02-03},
	journal = {Computer Methods and Programs in Biomedicine},
	author = {Lee, Daren and Dinov, Ivo and Dong, Bin and Gutman, Boris and Yanovsky, Igor and Toga, Arthur W.},
	month = jun,
	year = {2012},
	keywords = {Compute-bound, CUDA, Graphics Processing Unit (GPU), Memory-bound, Neuroimaging, Performance Optimization},
	pages = {175--187},
	file = {ScienceDirect Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\IK6WIRC3\\Lee et al. - 2012 - CUDA optimization strategies for compute- and memo.pdf:application/pdf;ScienceDirect Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\6WR5WAPT\\S0169260710002750.html:text/html}
}

@article{wilcox_advanced_2007,
	title = {Advanced reflector characterization with ultrasonic phased arrays in {NDE} applications},
	volume = {54},
	issn = {0885-3010},
	abstract = {Ultrasonic arrays are increasingly widely used in nondestructive evaluation (NDE) due to their greater flexibility and potentially superior performance compared to conventional monolithic probes. The characterization of small defects remains a challenge for NDE and is of great importance for determining the impact of a defect on the integrity of a structure. In this paper, a technique for characterizing reflectors with subwavelength dimensions is described. This is achieved by post-processing the complete data set of time traces obtained from an ultrasonic array using two algorithms. The first algorithm is used to obtain information about reflector orientation and the second algorithm is used to distinguish between point-like reflectors that reflect uniformly in all directions and specular reflectors that have distinct orientations. Experimental results are presented using a commercial 64-element, 5-MHZ array on two aluminum test specimens that contain a number of machined slots and side-drilled holes. The results show that the orientation of 1-mm-long slots can be determined to within a few degrees and that the signals from 1-mm-long slots can be distinguished from that from a 1-mm-diameter circular hole. Techniques for quantifying both the orientation and the specularity of measured signals are presented and the effect of processing parameters on the accuracy of results is discussed.},
	language = {eng},
	number = {8},
	journal = {IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control},
	author = {Wilcox, Paul D. and Holmes, Caroline and Drinkwater, Bruce W.},
	month = aug,
	year = {2007},
	pmid = {17703657},
	pages = {1541--1550}
}

@article{de_witte_power_1989,
	title = {Power plant life estimation and extension: {The} {Belgian} experience from the users' point of view},
	volume = {39},
	issn = {0308-0161},
	shorttitle = {Power plant life estimation and extension},
	url = {http://www.sciencedirect.com/science/article/pii/0308016189900379},
	doi = {10.1016/0308-0161(89)90037-9},
	abstract = {An overview of the Belgian power generation highlights the concern about life estimation and extension. A life assessment includes three main aspects: calculation, nondestructive examination and destructive testing or at least information on the actual material behaviour.

A number of examples illustrate the life assessment approaches and related experiences for various critical components in power plants. Improved reliability for long-term estimations in future should be based on experience, a more intensive service condition monitoring and ongoing research on the material behaviour.},
	number = {1–2},
	urldate = {2015-05-18},
	journal = {International Journal of Pressure Vessels and Piping},
	author = {de Witte, M.},
	year = {1989},
	pages = {41--55},
	file = {ScienceDirect Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\I8XERTPQ\\de Witte - 1989 - Power plant life estimation and extension The bel.pdf:application/pdf;ScienceDirect Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\AGS7ETCM\\0308016189900379.html:text/html}
}

@article{zhao_active_2007,
	title = {Active health monitoring of an aircraft wing with embedded piezoelectric sensor/actuator network: {I}. {Defect} detection, localization and growth monitoring},
	volume = {16},
	issn = {0964-1726},
	shorttitle = {Active health monitoring of an aircraft wing with embedded piezoelectric sensor/actuator network},
	url = {http://iopscience.iop.org/0964-1726/16/4/032},
	doi = {10.1088/0964-1726/16/4/032},
	abstract = {This work focuses on an ultrasonic guided wave structural health monitoring (SHM) system development for aircraft wing inspection. In part I of the study, a detailed description of a real aluminum wing specimen and some preliminary wave propagation tests on the wing panel are presented. Unfortunately, strong attenuation and scattering impede guided waves for large-area inspection. Nevertheless, small, low-cost and light-weight piezoelectric (PZT) discs were bonded to various parts of the aircraft wing, in a form of relatively sparse arrays, for simulated cracks and corrosion monitoring. The PZT discs take turns generating and receiving ultrasonic guided waves. Pair-wise through-transmission waveforms collected at normal conditions served as baselines, and subsequent signals collected at defected conditions such as rivet cracks or corrosion detected the presence of a defect and its location with a novel correlation analysis based technique called RAPID (reconstruction algorithm for probabilistic inspection of defects). The effectiveness of the algorithm was tested with several case studies in a laboratory environment. It showed good performance for defect detection, size estimation and localization in complex aircraft wing structures.},
	language = {en},
	number = {4},
	urldate = {2015-05-18},
	journal = {Smart Materials and Structures},
	author = {Zhao, Xiaoliang and Gao, Huidong and Zhang, Guangfan and Ayhan, Bulent and Yan, Fei and Kwan, Chiman and Rose, Joseph L.},
	month = aug,
	year = {2007},
	pages = {1208},
	file = {Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\AIEMUA5Q\\Zhao et al. - 2007 - Active health monitoring of an aircraft wing with .pdf:application/pdf;Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\ZXZJNWAV\\032.html:text/html}
}

@inproceedings{sasso_medical_2005,
	title = {Medical ultrasound imaging using the fully adaptive beamformer},
	volume = {2},
	doi = {10.1109/ICASSP.2005.1415448},
	abstract = {Not Available},
	booktitle = {{IEEE} {International} {Conference} on {Acoustics}, {Speech}, and {Signal} {Processing}, 2005. {Proceedings}. ({ICASSP} '05)},
	author = {Sasso, M. and Cohen-Bacrie, C.},
	month = mar,
	year = {2005},
	keywords = {adaptive array processing, adaptive beamforming, adaptive signal processing, array signal processing, beamformed radiofrequency signal, Biomedical imaging, biomedical ultrasonics, coherent signals, consecutive transmission lines, correlated signals, Covariance matrix, Delay, delay-and-sum operation, fully adaptive beamformer, medical signal processing, medical ultrasonic medium, medical ultrasound beamforming, Medical ultrasound imaging, off-axis energies, phased array imaging, Phased arrays, Power generation, Power transmission lines, Sensor arrays, spatial smoothing preprocessing, Transmission line matrix methods, ultrasonic imaging},
	pages = {489--492},
	file = {IEEE Xplore Abstract Record:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\T6ZPIPNJ\\icp.html:text/html}
}

@article{ellerman_note_1998,
	title = {Note on the seemingly indefinite extension of power plant lives, a panel contribution},
	volume = {19},
	copyright = {Copyright © 1998 International Association for Energy Economics},
	issn = {0195-6574},
	url = {http://www.jstor.org/stable/41322782},
	number = {2},
	urldate = {2015-05-18},
	journal = {The Energy Journal},
	author = {Ellerman, Denny},
	month = jan,
	year = {1998},
	pages = {129--132}
}

@article{ennis_recent_2003,
	title = {Recent advances in creep-resistant steels for power plant applications},
	volume = {28},
	issn = {0256-2499, 0973-7677},
	url = {http://link.springer.com/article/10.1007/BF02706455},
	doi = {10.1007/BF02706455},
	abstract = {The higher steam temperatures and pressures required to achieve increase in thermal efficiency of fossil fuel-fired power-generation plants necessitate the use of steels with improved creep rupture strength. The 9\% chromium steels developed during the last three decades are of great interest in such applications. In this report, the development of steels P91, P92 and E911 is described. It is shown that the martensitic transformation in these three steels produces high dislocation density that confers significant transient hardening. However, the dislocation density decreases during exposure at service temperatures due to recovery effects and for long-term creep strength the sub-grain structure produced under different conditions is most important. The changes in the microstructure mean that great care is needed in the extrapolation of experimental data to obtain design values. Only data from tests with rupture times above 3,000 h provide reasonable extrapolated values. It is further shown that for the 9\% chromium steels, oxidation resistance in steam is not sufficiently high for their use as thin-walled components at temperatures of 600°C and above. The potential for the development of steels of higher chromium contents (above 11\%) to give an improvement in steam oxidation resistance whilst maintaining creep resistance to the 9\% chromium steels is discussed.},
	language = {en},
	number = {3-4},
	urldate = {2015-05-18},
	journal = {Sadhana},
	author = {Ennis, P. J. and Czyrska-Filemonowicz, A.},
	month = jun,
	year = {2003},
	keywords = {Chromium steels, creep rupture strength, Engineering, general, power/plant components, steam oxidation},
	pages = {709--730},
	file = {Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\82X49AMQ\\Ennis and Czyrska-Filemonowicz - 2003 - Recent advances in creep-resistant steels for powe.pdf:application/pdf;Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\GT74FJ6W\\BF02706455.html:text/html}
}

@book{rice_mechanics_1976,
	title = {Mechanics of {Crack} {Growth}},
	language = {en},
	publisher = {ASTM International},
	author = {Rice, J. R.},
	month = jan,
	year = {1976}
}

@book{morse_methods_1953,
	address = {Boston, Mass},
	title = {Methods of {Theoretical} {Physics}, {Part} {I}},
	isbn = {978-0-07-043316-8},
	abstract = {THE classic text for applied mathematics. This is truly a work of art - with its clear explanations and its fantastic stereoscopic illustrations. Yes, it may be a little dated; and yes, it is definitely not an easy read; but its clarity of content and its sheer mathematical elegance make it more than worthwhile for any serious student of physics or engineering. And one thing is certain: anybody able to successfully complete and really understand the material presented in this book will have become VERY well versed in applied mathematics.
- From a review on Goodreads},
	language = {English},
	publisher = {McGraw-Hill Science/Engineering/Math},
	author = {Morse, Philip McCord and Feshbach, Herman},
	month = jun,
	year = {1953}
}

@article{nowicki_influence_2007,
	title = {Influence of the ultrasound transducer bandwidth on selection of the complementary {Golay} bit code length},
	volume = {47},
	issn = {1874-9968},
	doi = {10.1016/j.ultras.2007.07.003},
	abstract = {In contrast to previously published papers [A. Nowicki, Z. Klimonda, M. Lewandowski, J. Litniewski, P.A. Lewin, I. Trots, Comparison of sound fields generated by different coded excitations - Experimental results, Ultrasonics 44 (1) (2006) 121-129; J. Litniewski, A. Nowicki, Z. Klimonda, M. Lewandowski, Sound fields for coded excitations in water and tissue: experimental approach, Ultrasound Med. Biol. 33 (4) (2007) 601-607], which examined the factors influencing the spatial resolution of coded complementary Golay sequences (CGS), this paper investigates the effect of ultrasound imaging transducer's fractional bandwidth on the gain of the compressed echo signal for different spectral widths of the CGS. Two different bit lengths were considered, specifically one and two cycles. Three transducers having fractional bandwidth of 25\%, 58\% and 80\% and operating at frequencies 6, 4.4 and 6 MHz, respectively were examined (one of the 6 MHz sources was focused and made of composite material). The experimental results have shown that by increasing the code length, i.e. decreasing the bandwidth, the compressed echo amplitude could be enhanced. The smaller the bandwidth was the larger was the gain; the pulse-echo sensitivity of the echo amplitude increased by 1.88, 1.62 and 1.47, for 25\%, 58\% and 80\% bandwidths, respectively. These results indicate that two cycles bit length excitation is more suitable for use with bandwidth limited commercially available imaging transducers. Further, the time resolution is retained for transducers with two cycles excitation providing the fractional bandwidth is lower than approximately 90\%. The results of this work also show that adjusting the code length allows signal-to-noise-ratio (SNR) to be enhanced while using limited (less that 80\%) bandwidth imaging transducers. Also, for such bandwidth limited transducers two cycles excitation would not decrease the time resolution, obtained with "conventional" spike excitation. Hence, CGS excitation could be successfully implemented with the existing, relatively narrow band imaging transducers without the need to use usually more expensive wideband, composite ones.},
	language = {eng},
	number = {1-4},
	journal = {Ultrasonics},
	author = {Nowicki, A. and Trots, I. and Lewin, P. A. and Secomski, W. and Tymkiewicz, R.},
	month = dec,
	year = {2007},
	pmid = {17825338},
	keywords = {Data Compression, Equipment Design, Equipment Failure Analysis, Reproducibility of Results, Sensitivity and Specificity, Signal Processing, Computer-Assisted, Transducers, Ultrasonography},
	pages = {64--73}
}

@inproceedings{saniie_life_1990,
	title = {Life assessment of creep degraded super alloy materials using ultrasound},
	doi = {10.1109/ULTSYM.1990.171510},
	abstract = {The potential of ultrasound for characterizing creep damage in superalloy materials was evaluated. Several samples of IN-738, a superalloy used in many gas turbines, were heat treated at a temperature of 1520°F under 40-kpsi stress for times ranging from 500 to 900 h. Both ultrasonic attenuation and velocity measurements using a 20-MHz transducer were employed for characterizing the samples. It is shown that velocity measurements lack quantitative value since significant variability exists in the samples prior to creep damage. However, attenuation measurements clearly distinguish between fresh specimens and samples with creep damage},
	booktitle = {Ultrasonics {Symposium}, 1990. {Proceedings}., {IEEE} 1990},
	author = {Saniie, J. and Panda, B. and Wang, T. and Nagle, D.T.},
	month = dec,
	year = {1990},
	keywords = {1520 degF, Aging, Attenuation, Blades, chromium alloys, cobalt alloys, creep, creep damage, creep degraded super alloy materials, creep fracture, Degradation, fresh specimens, gas turbines, life assessment, Mechanical factors, Microstructure, nickel alloys, Ni-Cr-Co, superalloys, transducer, Turbines, ultrasonic attenuation, ultrasonic imaging, ultrasonic materials testing, ultrasonic velocity measurements, Velocity measurement},
	pages = {987--990 vol.2},
	file = {IEEE Xplore Abstract Record:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\MU3NG3C6\\abs_all.html:text/html;IEEE Xplore Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\8NWDHZH9\\Saniie et al. - 1990 - Life assessment of creep degraded super alloy mate.pdf:application/pdf}
}

@article{descamps_efficiency_2008,
	series = {{PRES} 2006. 9th {Conference} of {Process} {Integration}, {Modelling} and {Optimisation} for {Energy} {Saving} and {Pollution} {Reduction} - {PRES} 2006 {PRES} 2006},
	title = {Efficiency of an {Integrated} {Gasification} {Combined} {Cycle} ({IGCC}) power plant including {CO}2 removal},
	volume = {33},
	issn = {0360-5442},
	url = {http://www.sciencedirect.com/science/article/pii/S0360544207001260},
	doi = {10.1016/j.energy.2007.07.013},
	abstract = {This study is devoted to technical evaluation of a carbon dioxide removal in an existing Integrated Gasification Combined Cycle (IGCC) plant. This IGCC case is based on an oxygen blown entrained flow gasifier operating at 27 bar, the removal of acid gas (H2S) is performed with MDEA unit, the efficiency of this IGCC is 43\% based on the low heating value (LHV) of coal. A carbon dioxide separation unit conveniently integrated in a pre-combustion separation process is chosen, in order to take advantage of the high pressure of the gas. The methanol process for carbon dioxide removal is integrated downstream the existing desulfuration unit, and after a CO shift conversion unit. In this study, the integration of the CO2 capture process to the IGCC is simulated as realistically as possible. The design parameters of both the gas turbine (the turbine inlet temperature, compressor pressure ratio, reduced flow rate) and the steam turbine (Stodola parameter) are taken into account. Maintenance of low NO x production in the combustion chamber is also considered. The production of NO x is supposed to be influenced by the low heating value of the gas which is maintained as low as for case of the synthesis gas without CO2 capture. Thus the choice is made to feed the gas turbine of the combined cycle with a diluted synthesis gas, having similar low heating value than the one produced without the CO2 capture. Plant performances for different conversion and capture rates are compared. A final optimized integration is given for 92 mol\% CO conversion rate and 95 mol\% CO2 absorption rates, a comparison with former studies is proposed.},
	number = {6},
	urldate = {2015-05-18},
	journal = {Energy},
	author = {Descamps, C. and Bouallou, C. and Kanniche, M.},
	month = jun,
	year = {2008},
	keywords = {Capture, CO2 removal, IGCC, Physical absorption, Pre-combustion},
	pages = {874--881},
	file = {ScienceDirect Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\M3NJE237\\Descamps et al. - 2008 - Efficiency of an Integrated Gasification Combined .pdf:application/pdf;ScienceDirect Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\WAXXPMU4\\S0360544207001260.html:text/html}
}

@article{kummer_ultra-low_1963,
	title = {Ultra-low sidelobes from time-modulated arrays},
	volume = {11},
	issn = {0018-926X},
	doi = {10.1109/TAP.1963.1138102},
	abstract = {Antenna patterns with ultra-low sidelobes have been obtained for an experimental receiving array designed with time-modulated slot radiators. The technique utilizes on-off RF switches which are programmed in a predetermined sequence to produce the desired pattern. The results of tests on an experimental eight-element slot array designed for sidelobe reduction are presented. Two examples are considered: 1) an initial static pattern with 30-db sidelobes which are reduced to about 40 db by sequential switching and 2) an initial static pattern with 13-db sidelobes which are reduced directly to about 40 db by a different sequence of switching. Measured patterns illustrating the sidelobe reduction are included. The applicability of the sidelobe reduction technique to large electronically steerable phased arrays is considered briefly and it is concluded that it is compatible with such systems.},
	number = {6},
	journal = {IEEE Transactions on Antennas and Propagation},
	author = {Kummer, W.H. and Villeneuve, A.T. and Fong, T. and Terrio, F.},
	month = nov,
	year = {1963},
	keywords = {Aerospace electronics, Aircraft, Antenna arrays, Antenna measurements, Antenna transient analysis, Apertures, Helium, Phased arrays, Pulse modulation, Radio frequency, Receiving antennas, Slot arrays, Switches, Testing},
	pages = {633--639},
	file = {01138102.pdf:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\4A5MN8B6\\01138102.pdf:application/pdf;IEEE Xplore Abstract Record:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\SNCAF4AQ\\Kummer et al. - 1963 - Ultra-low sidelobes from time-modulated arrays.html:text/html}
}

@article{sposito_review_2010,
	title = {A review of non-destructive techniques for the detection of creep damage in power plant steels},
	volume = {43},
	issn = {0963-8695},
	url = {http://www.sciencedirect.com/science/article/pii/S0963869510000654},
	doi = {10.1016/j.ndteint.2010.05.012},
	abstract = {The assessment of creep damage in steels employed in the power generation industry is usually carried out by means of replica metallography, but the several shortcomings of this method have prompted a search for alternative or complementary non-destructive techniques, ranging from ultrasonic to electromagnetic methods, hardness measurements and nuclear techniques. A critical review of the main results obtained to date in the secondary and tertiary stages of creep is presented in this paper, and the advantages and disadvantages of each method are discussed. Ultrasonic and potential drop techniques appear to be the most promising, but further research is needed before they are fully mature for deployment in the field.},
	number = {7},
	urldate = {2015-05-18},
	journal = {NDT \& E International},
	author = {Sposito, G. and Ward, C. and Cawley, P. and Nagy, P. B. and Scruby, C.},
	month = oct,
	year = {2010},
	keywords = {creep damage, Power plant steels},
	pages = {555--567},
	file = {ScienceDirect Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\PIIVHHFN\\Sposito et al. - 2010 - A review of non-destructive techniques for the det.pdf:application/pdf;ScienceDirect Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\TEH5FNS7\\S0963869510000654.html:text/html}
}

@article{ray_residual_2000,
	title = {Residual life prediction of service exposed main steam pipe of boilers in a thermal power plant},
	volume = {7},
	issn = {1350-6307},
	url = {http://www.sciencedirect.com/science/article/pii/S1350630799000242},
	doi = {10.1016/S1350-6307(99)00024-2},
	abstract = {This paper deals with residual life prediction methodology for more than 12.5 years service exposed main steam pipes of various boilers in a thermal power plant. Health assessment was made using destructive accelerated stress rupture and tensile tests at different temperatures, and some nondestructive tests. There was no evidence of localised damage in the form of surface cracks, cavitation or dents in the service exposed main steam pipes of all the boilers. So far as the remaining life at 550°C is concerned, it is possible to obtain a life of greater than 100,000 h at the hoop stress level of the service exposed pipes, provided no localised damage in the form of cracks or dents have been developed. It is recommended that a health check may be carried out after 50,000 h of service exposure at 550°C.},
	number = {5},
	urldate = {2015-05-18},
	journal = {Engineering Failure Analysis},
	author = {Ray, A. K. and Tiwari, Y. N. and Sinha, R. K. and Chaudhuri, S. and Singh, R.},
	month = oct,
	year = {2000},
	keywords = {Boiler failures, Remaining life, Service exposed, Stress rupture test, Tensile properties},
	pages = {359--376},
	file = {ScienceDirect Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\I2MF9FS5\\Ray et al. - 2000 - Residual life prediction of service exposed main s.pdf:application/pdf;ScienceDirect Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\CVMXIQ5D\\S1350630799000242.html:text/html}
}

@article{jiang_grain_1998,
	title = {Grain growth behavior of nanocrystalline {Inconel} 718 and {Ni} powders and coatings},
	volume = {10},
	issn = {0965-9773},
	url = {http://www.sciencedirect.com/science/article/pii/S0965977398000580},
	doi = {10.1016/S0965-9773(98)00058-0},
	abstract = {Nanocrystalline Inconel 718 and Ni powders were prepared using two approaches: methanol and cryogenic attritor milling. High velocity oxy-fuel (HVOF) spraying of milled Inconel 718 powders was then utilized to produce coatings with a nanocrystalline grain size. Isothermal heat treatments were carried out to study the thermal stability of the methanol milled and cryomilled powders, as well as the HVOF-derived coatings. All nanocrystalline Inconel 718 powders and coatings studied herein exhibited significant thermal stability against grain growth by maintaining a grain size around 100 nm following annealing at 1273 K for 60 min. In the case of the cryomilled nanocrystalline Ni powders, isothermal grain growth behavior was studied, from which the parameters required for the prediction of the microstructural evolution during a non-isothermal annealing were acquired. The theoretical simulation of grain growth behavior of nanocrystalline Ni during non-isothermal annealing conditions yields results that are in good agreement with the experimental results.},
	number = {2},
	urldate = {2015-05-18},
	journal = {Nanostructured Materials},
	author = {Jiang, H. G. and Lau, M. L. and Lavernia, E. J.},
	month = feb,
	year = {1998},
	pages = {169--178},
	file = {ScienceDirect Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\U7XZ9CW8\\Jiang et al. - 1998 - Grain growth behavior of nanocrystalline Inconel 7.pdf:application/pdf;ScienceDirect Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\98FNCGBZ\\S0965977398000580.html:text/html}
}

@article{fan_comparison_2014,
	title = {A comparison between ultrasonic array beamforming and super resolution imaging algorithms for non-destructive evaluation},
	volume = {54},
	issn = {0041-624X},
	url = {http://www.sciencedirect.com/science/article/pii/S0041624X13003661},
	doi = {10.1016/j.ultras.2013.12.012},
	abstract = {In this paper the total focusing method, the so called gold standard in classical beamforming, is compared with the widely used time-reversal MUSIC super resolution technique in terms of its ability to resolve closely spaced scatterers in a solid. The algorithms are tested with simulated and experimental array data, each containing different noise levels. The performance of the algorithms is evaluated in terms of lateral resolution and sensitivity to noise. It is shown that for the weak noise situation (SNR \> 20 dB), time-reversal MUSIC provides significantly enhanced lateral resolution when compared to the total focusing method, breaking the diffraction limit. However, for higher noise levels, the total focusing method is shown to be robust, whilst the performance of time-reversal MUSIC is degraded. The influence of multiple scattering on the imaging algorithms is also investigated and shown to be small.},
	number = {7},
	urldate = {2015-02-15},
	journal = {Ultrasonics},
	author = {Fan, Chengguang and Caleap, Mihai and Pan, Mengchun and Drinkwater, Bruce W.},
	month = sep,
	year = {2014},
	keywords = {lateral resolution, Modelling, noise, Post processing, Ultrasonic array},
	pages = {1842--1850},
	file = {ScienceDirect Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\5V5TPG8K\\Fan et al. - 2014 - A comparison between ultrasonic array beamforming .pdf:application/pdf;ScienceDirect Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\D2ZH6NJP\\S0041624X13003661.html:text/html}
}

@article{viswanathan_u.s._2005,
	title = {U.{S}. program on materials technology for ultra-supercritical coal power plants},
	volume = {14},
	issn = {1059-9495, 1544-1024},
	url = {http://link.springer.com/article/10.1361/10599490524039},
	doi = {10.1361/10599490524039},
	abstract = {The efficiency of conventional fossil power plants is a strong function of the steam temperature and pressure. Research to increase both has been pursued worldwide, since the energy crisis in the 1970s. The need to reduce CO2 emissions has recently provided an additional incentive to increase efficiency. More recently, interest has been evinced in advanced combustion technologies utilizing oxygen instead of air for combustion. The main enabling technology in achieving the above goals is the development of stronger high temperature materials. Extensive research-and-development programs have resulted in numerous high-strength alloys for heavy section piping and for tubing needed to build boilers. The study reported on here is aimed at identifying, evaluating, and qualifying the materials needed for the construction of the critical components of coal-fired boilers that are capable of operating with steam at temperatures of 760 °C (1400 °F) and pressures of 35 MPa (5000 psi). The economic viability of such a plant has been explored. Candidate alloys applicable to various ranges of temperatures have been identified. Stress rupture tests have been completed on the base metal and on welds to a number of alloys. Steamside oxidation tests in an autoclave at 650 °C (1200 °F) and 800 °C (1475 °F) have been completed. Fireside corrosion tests have been conducted under conditions simulating those of waterwalls and superheater/reheater tubes. The weldability and fabricability of the alloys have been investigated. The capabilities of various overlay coatings and diffusion coatings have been examined. This article provides a status report on the progress achieved to date on this project.},
	language = {en},
	number = {3},
	urldate = {2015-05-18},
	journal = {Journal of Materials Engineering and Performance},
	author = {Viswanathan, R. and Henry, J. F. and Tanzosh, J. and Stanko, G. and Shingledecker, J. and Vitalis, B. and Purgert, R.},
	month = jun,
	year = {2005},
	keywords = {Characterization and Evaluation of Materials, Corrosion, creep, efficiency, emissions, Engineering Design, fabrication, Materials Science, power plants, Quality Control, Reliability, Safety and Risk, Stress, Tribology, Corrosion and Coatings, welding},
	pages = {281--292},
	file = {Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\GQVPVD68\\Viswanathan et al. - 2005 - U.S. program on materials technology for ultra-sup.pdf:application/pdf;Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\ARF2RVXU\\10599490524039.html:text/html}
}

@inproceedings{kuhnicke_limitations_1999,
	title = {The limitations of {Snell}'s law in the design of ultrasound transducers},
	volume = {2},
	doi = {10.1109/ULTSYM.1999.849184},
	abstract = {Because the refracted sound field of a finite beam extremely depends on the size and on the frequency of the generating element, Snell's law is not applicable to calculate the refraction angle of a finite beam. Approaches using plane reflection and transmission coefficient in connection with a discretization of the source into elementary point sources are more exact. This paper demonstrates that the application of plane reflection and transmission coefficients requires a point to point distance smaller than a half wavelength, in order to obtain an accurate sound field of the refracted beam},
	booktitle = {1999 {IEEE} {Ultrasonics} {Symposium}, 1999. {Proceedings}},
	author = {Kuhnicke, E.},
	year = {1999},
	keywords = {Acoustic beams, Acoustic refraction, acoustic transducers, finite beam, Optical reflection, plane reflection, Probes, refracted sound field, refraction angle, Snell's law, Solid modeling, Stress, Testing, transmission coefficient, ultrasonic imaging, ultrasonic refraction, Ultrasonic transducers, ultrasound transducers},
	pages = {1067--1070 vol.2},
	file = {IEEE Xplore Abstract Record:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\VXXQJB6I\\login.html:text/html}
}

@book{szilard_ultrasonic_1982,
	address = {Chichester Eng. ; New York},
	title = {Ultrasonic {Testing}: {Non}-conventional {Testing} {Techniques}},
	isbn = {978-0-471-27938-9},
	shorttitle = {Ultrasonic {Testing}},
	language = {English},
	publisher = {Wiley-Blackwell},
	author = {Szilard, J.},
	month = apr,
	year = {1982}
}

@misc{weisstein_quintic_????,
	type = {Text},
	title = {Quintic {Equation}},
	copyright = {Copyright 1999-2015 Wolfram Research, Inc.  See http://mathworld.wolfram.com/about/terms.html for a full terms of use statement.},
	url = {http://mathworld.wolfram.com/QuinticEquation.html},
	abstract = {Unlike quadratic, cubic, and quartic polynomials, the general quintic cannot be solved algebraically in terms of a finite number of additions, subtractions, multiplications, divisions, and root extractions, as rigorously demonstrated by Abel (Abel's impossibility theorem) and Galois. However, certain classes of quintic equations can be solved in this manner. Irreducible quintic equations can be associated with a Galois group, which may be a symmetric group S\_n, metacyclic group M\_n, dihedral...},
	language = {en},
	urldate = {2015-03-15},
	author = {Weisstein, Eric W.},
	file = {Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\M5SSQNRN\\QuinticEquation.html:text/html}
}

@article{drinkwater_ultrasonic_2006,
	title = {Ultrasonic arrays for non-destructive evaluation: {A} review},
	volume = {39},
	issn = {0963-8695},
	shorttitle = {Ultrasonic arrays for non-destructive evaluation},
	url = {http://www.sciencedirect.com/science/article/pii/S0963869506000272},
	doi = {10.1016/j.ndteint.2006.03.006},
	abstract = {An ultrasonic array is a single transducer that contains a number of individually connected elements. Recent years have seen a dramatic increase in the use of ultrasonic arrays for non-destructive evaluation. Arrays offer great potential to increase inspection quality and reduce inspection time. Their main advantages are their increased flexibility over traditional single element transducer methods, meaning that one array can be used to perform a number of different inspections, and their ability to produce immediate images of the test structure. These advantages have led to the rapid uptake of arrays by the engineering industry. These industrial applications are underpinned by a wide range of published research which describes new piezoelectric materials, array geometries, modelling methods and inspection modalities. The aim of this paper is to bring together the most relevant published work on arrays for non-destructive evaluation applications, comment on the state-of the art and discuss future directions. There is also a significant body of published literature referring to use of arrays in the medical and sonar fields and the most relevant papers from these related areas are also reviewed. However, although there is much common ground, the use of arrays in non-destructive evaluation offers some distinctly different challenges to these other disciplines.},
	number = {7},
	urldate = {2015-05-18},
	journal = {NDT \& E International},
	author = {Drinkwater, Bruce W. and Wilcox, Paul D.},
	month = oct,
	year = {2006},
	keywords = {Arrays, Modelling, Signal processing, Ultrasonic},
	pages = {525--541},
	file = {ScienceDirect Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\NHPXZUWD\\Drinkwater and Wilcox - 2006 - Ultrasonic arrays for non-destructive evaluation .pdf:application/pdf;ScienceDirect Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\QVZP3GJA\\S0963869506000272.html:text/html}
}

@article{tong_creep_2001,
	title = {Creep, fatigue and oxidation in crack growth in advanced nickel base superalloys},
	volume = {23},
	issn = {0142-1123},
	url = {http://www.sciencedirect.com/science/article/pii/S0142112301000494},
	doi = {10.1016/S0142-1123(01)00049-4},
	abstract = {This paper presents some of our recent results from an ongoing collaborative research programme on creep-fatigue behaviour of two advanced nickel base superalloys for turbine disc applications. The role of creep, fatigue and oxidation in crack growth has been investigated at 650°C under typical loading waveforms at selected loading frequencies. Load-line deflections were monitored in selected tests under static and long dwell loading conditions. Scanning electron microscopy was adopted to identify the fracture mode and to facilitate the evaluation of oxidation.

The results show that mixed time and cycle dependent crack growth seems to be the predominant crack growth mode in the two PM nickel alloys studied. Whilst limited creep may be present at the crack tip, particularly under static and long dwell loading conditions, oxidation appears to be the predominant mechanism for crack growth under the test conditions examined.},
	number = {10},
	urldate = {2015-05-18},
	journal = {International Journal of Fatigue},
	author = {Tong, J. and Dalby, S. and Byrne, J. and Henderson, M. B. and Hardy, M. C.},
	month = nov,
	year = {2001},
	keywords = {creep, Fatigue crack growth, Load-line deflection, Nickel base superalloys, oxidation, Waveform},
	pages = {897--902},
	file = {ScienceDirect Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\H87QNV6B\\Tong et al. - 2001 - Creep, fatigue and oxidation in crack growth in ad.pdf:application/pdf;ScienceDirect Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\68GHRISE\\S0142112301000494.html:text/html}
}

@article{viswanathan_materials_2001,
	title = {Materials for ultrasupercritical coal power plants—{Boiler} materials: {Part} 1},
	volume = {10},
	issn = {1059-9495, 1544-1024},
	shorttitle = {Materials for ultrasupercritical coal power plants—{Boiler} materials},
	url = {http://link.springer.com/article/10.1361/105994901770345394},
	doi = {10.1361/105994901770345394},
	abstract = {The efficiency of conventional boiler/steam turbine fossil power plants is a strong function of the steam temperature and pressure. Research to increase both has been pursued worldwide, since the energy crisis in the 1970s. The need to reduce CO2 emission has recently provided an additional incentive to increase efficiency. Thus, steam temperatures of the most efficient fossil power plants are now in the 600 °C (1112 °F) range, which represents an increase of about 60 °C (108 °F) in 30 years. It is expected that steam temperatures will rise another 50 to 100 °C (90 to 180 °F) in the next 30 years. The main enabling technology is the development of stronger high-temperature materials, capable of operating under high stresses at ever-increasing temperatures. Recently, the EPRI performed a state-of-the-art review of materials technology for advanced boiler/steam turbine power plants (ultrasupercritical power plants). The results of the review show that with respect to boilers, high-strength ferritic 9–12Cr steels for use in thick section components are now commercially available for temperatures up to 620 °C (1150 °F). Initial data on two experimental 12Cr ferritic steels indicate that they may be capable of long-term service up to 650 °C (1112 °F), but more data are required to confirm this. For higher temperatures, austenitic steels and Ni-based alloys are needed. Advanced austenitic stainless steels for use as super and reheater tubing are available for service temperatures up to 650 °C (1112 °F) and possibly 700 °C (1292 °F). Ni-based superalloys would be needed for higher temperatures. None of these steels have been approved by the ASME Boiler Code Group so far. Higher-strength materials are needed for upper water walls of boilers with steam pressure above 24 MPa (3400 psi). A high-strength 2-1/2\%Cr steel recently ASME code approved as T-23 is the preferred candidate material for this application. Field trials are in progress. This paper will present the results of the EPRI review in detail, relating to boiler material. Results relating to turbine materials are presented in a companion paper as Part 2.},
	language = {en},
	number = {1},
	urldate = {2015-05-18},
	journal = {Journal of Materials Engineering and Performance},
	author = {Viswanathan, R. and Bakker, W.},
	month = feb,
	year = {2001},
	keywords = {boilers, Characterization and Evaluation of Materials, creep, Engineering Design, fatigue, material, Materials Science, oxidation, Quality Control, Reliability, Safety and Risk, supercritical, Tribology, Corrosion and Coatings},
	pages = {81--95},
	file = {Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\KR23CMRH\\Viswanathan and Bakker - 2001 - Materials for ultrasupercritical coal power plants.pdf:application/pdf;Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\TUXTSWSU\\105994901770345394.html:text/html}
}

@article{thomas_power-plant_1988,
	title = {Power-plant life extension},
	volume = {13},
	issn = {0360-5442},
	url = {http://www.sciencedirect.com/science/article/pii/0360544288900606},
	doi = {10.1016/0360-5442(88)90060-6},
	abstract = {In this paper we examine the rationale for increased interest in extending the life of a power-plant well beyond its design lifetime. In particular, we examine the technical, economic and regulatory factors that have radically altered the attractiveness of retaining old plant compared to building new plant. The experience of refurbishment in the U.S.A. and U.K. is reviewed and the major markets for the 1990s are identified. It is concluded that for utilities, refurbishment represents a useful increase in the range of generating options open to them. The impact on the heavy electrical industry is likely to be less favourable, leading to a need for reductions in capacity and a continuation of the trend towards mergers and international collaborations that has been a feature of the past 20 yr.},
	number = {10},
	urldate = {2015-05-18},
	journal = {Energy},
	author = {Thomas, Steve},
	month = oct,
	year = {1988},
	pages = {767--786},
	file = {ScienceDirect Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\SQD2AF93\\Thomas - 1988 - Power-plant life extension.pdf:application/pdf;ScienceDirect Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\UISRAIMT\\0360544288900606.html:text/html}
}

@inproceedings{ford_development_1988,
	title = {Development and use of a predictive model of crack propagation in 304/316L, {A}533B/{A}508 and {Inconel} 600/182 alloys in 288$^{\textrm{0}}${C} water},
	url = {http://inis.iaea.org/Search/search.aspx?orig_q=RN:20057187},
	urldate = {2015-05-18},
	booktitle = {Proceedings of the third international symposium on environmental degradation of materials in nuclear power systems},
	author = {Ford, F. P. and Andresen, P. L.},
	year = {1988},
	pages = {789--800},
	file = {Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\79VPWDFJ\\search.html:text/html}
}

@inproceedings{roscoe_cost-effective_1995,
	address = {Kyoto},
	title = {Cost-{Effective} {Inspection} {Qualification}},
	url = {http://www.osti.gov/scitech/biblio/86127},
	language = {English},
	urldate = {2015-05-18},
	booktitle = {Proceedings of the 13. international conference on {NDE} in the nuclear and pressure vessel industries},
	publisher = {ASM International},
	author = {Roscoe, P. and Waites, C. and Whittle, M. J.},
	month = aug,
	year = {1995},
	keywords = {comparative evaluations, equipment, inspection, nondestructive testing, nuclear power plants, nuclear power reactors and associated plants, performance, reactor components, sizewell-b reactor, standards},
	file = {Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\2EFX69MW\\86127.html:text/html}
}

@article{smith_high-speed_1991,
	title = {High-speed ultrasound volumetric imaging system. {I}. {Transducer} design and beam steering},
	volume = {38},
	url = {http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=68466},
	number = {2},
	urldate = {2015-03-14},
	journal = {IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control},
	author = {Smith, Stephen W. and Pavy Jr, Henry G. and von Ramm, Olaf T.},
	year = {1991},
	pages = {100--108},
	file = {Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\N5CTZ9Q2\\login.html:text/html}
}

@inproceedings{lambert_performance_2012,
	title = {Performance evaluation of total focusing method on {GPP} and {GPU}},
	url = {http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=6385392},
	urldate = {2013-05-25},
	booktitle = {Design and {Architectures} for {Signal} and {Image} {Processing} ({DASIP}), 2012 {Conference} on},
	author = {Lambert, Jason and Pedron, Antoine and Gens, Guillaume and Bimbard, Franck and Lacassagne, Lionel and Iakovleva, Ekaterina},
	year = {2012},
	pages = {1--8},
	file = {06385392.pdf:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\FUCE2BWQ\\06385392.pdf:application/pdf}
}

@article{was_influence_1981,
	title = {The influence of thermal treatment on the chemistry and structure of grain boundaries in inconel 600},
	volume = {12},
	issn = {0360-2133, 1543-1940},
	url = {http://link.springer.com/article/10.1007/BF02643684},
	doi = {10.1007/BF02643684},
	abstract = {Although it is widely accepted that certain heat treatments result in carbide precipitation accompanied by chromium depletion at the grain boundaries, no direct evidence of this phenomenon exists for Inconel 600. Using the Scanning Transmission Electron Microscope (STEM), the extent of grain boundary chromium depletion is quantitatively determined as a function of thermal treatment time at 700 °C following a 30 min solution anneal at 1100 °C. Results confirm the presence of grain boundary chromium depletion that varies in extent with time at temperature, the chromium concentration falling to values as low as 3 wt pct. The chromium depletion volume is characterized by a depletion parameter which is correlated with intergranular corrosion test results to determine a self-healing (desensitization) chromium concentration of 9 wt pct. Trace element segregation at grain boundaries is measured by Auger Electron Spectroscopy (AES) as a function of aging treatment. Results show that after thermally treating samples for various times at 700 °C, phosphorus is always present at the grain boundaries. Intergranular corrosion behavior as a function of thermal treatment appears to be governed more strongly by chromium depletion than trace element segregation.},
	language = {en},
	number = {8},
	urldate = {2015-05-18},
	journal = {Metallurgical Transactions A},
	author = {Was, G. S. and Tischner, H. H. and Latanision, R. M.},
	month = aug,
	year = {1981},
	keywords = {Ceramics, Glass, Composites, Natural Methods, Materials Science, Metallic Materials, Physical Chemistry, Structural Materials},
	pages = {1397--1408},
	file = {Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\UAJF6P7U\\BF02643684.html:text/html}
}

@article{dominelli_life_2006,
	title = {Life extension and condition assessment: techniques for an aging utility infrastructure},
	volume = {4},
	issn = {1540-7977},
	shorttitle = {Life extension and condition assessment},
	doi = {10.1109/MPAE.2006.1632451},
	abstract = {Many utilities are focusing their efforts on developing methods to assess the condition of equipment to extend the life of existing infrastructure. In many cases, these utilities focus their efforts on extending the life of power transformers and paper-insulated lead-covered (PILC) cables because these components offer the greatest payback. Extending the life of aging infrastructure requires the use of noninvasive condition assessment and online preventive techniques that can easily be implemented in the field. Such condition monitoring, assessment, and life extension techniques will help utilities decide whether an aging transformer or underground PILC distribution cable can be operated reliably beyond its design life},
	number = {3},
	journal = {IEEE Power and Energy Magazine},
	author = {Dominelli, N. and Rao, A. and Kundur, P.},
	month = may,
	year = {2006},
	keywords = {arc light emissions, Cables, condition assessment, condition monitoring, condition monitoring techniques, Current measurement, custom software, Europe, innovative inspection techniques, inspection, Investments, lead sheath, life extension, life testing, load tap changer, maintenance engineering, Medium voltage, nondestructive inspection techniques, North America, oil tests, paper insulated lead cover cables, power cable testing, Power supplies, Power transformers, power transformers aging, power transformer testing, Substations, underground PILC distribution cables},
	pages = {24--35},
	file = {IEEE Xplore Abstract Record:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\DW9AWAT2\\articleDetails.html:text/html;IEEE Xplore Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\2JA5PJ2S\\Dominelli et al. - 2006 - Life extension and condition assessment technique.pdf:application/pdf}
}

@misc{feldman_derivation_2000,
	address = {The University of British Columbia},
	title = {Derivation of the {Wave} {Equation}},
	urldate = {2015-07-03},
	author = {Feldman, Joel},
	year = {2000}
}

@article{viswanathan_materials_2006,
	series = {International {Conference} {WELDS} 2005},
	title = {Materials for ultra-supercritical coal-fired power plant boilers},
	volume = {83},
	issn = {0308-0161},
	url = {http://www.sciencedirect.com/science/article/pii/S0308016106001475},
	doi = {10.1016/j.ijpvp.2006.08.006},
	abstract = {The efficiency of conventional fossil power plants is a strong function of the steam temperature and pressure. Research to increase both has been pursued worldwide, since the energy crisis in the 1970s. The need to reduce CO2 emission has recently provided an additional incentive to increase efficiency. The main enabling technology in achieving the above goals has been the development of stronger high-temperature materials. Extensive R\&D programs have resulted in numerous high strength alloys for heavy section piping, and tubing needed to build boilers. The study reported here is aimed at identifying, evaluating and qualifying the materials needed for the construction of the critical components of coal-fired boilers capable of operating with 760 °C (1400 °F)/35 MPa (5000 psi) steam. The economic viability of such a plant has been explored. Candidate alloys applicable to various ranges of temperature have been identified. Stress rupture tests have been completed on the base metal and on welds to a number of alloys. Steamside oxidation tests in an autoclave at 650 (1200 °F) and 800 °C (1475 °F) have been completed. Fireside corrosion tests have been conducted under conditions simulating those of waterwalls and superheater/reheater tubes. Weldability and fabricability of the alloys have been investigated. The capability of various overlay coatings and diffusion coatings have been examined. This paper provides a status report on the progress achieved to date on this project.},
	number = {11–12},
	urldate = {2015-05-18},
	journal = {International Journal of Pressure Vessels and Piping},
	author = {Viswanathan, R. and Coleman, K. and Rao, U.},
	month = nov,
	year = {2006},
	pages = {778--783},
	file = {ScienceDirect Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\C3KCSB79\\Viswanathan et al. - 2006 - Materials for ultra-supercritical coal-fired power.pdf:application/pdf;ScienceDirect Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\2XRTAMVT\\S0308016106001475.html:text/html}
}

@book{bush_nondestructive_1989,
	title = {Nondestructive {Testing} of {Pavements} and {Backcalculation} of {Moduli}},
	isbn = {978-0-8031-1260-5},
	language = {en},
	publisher = {ASTM International},
	author = {Bush, Albert Jasper and Baladi, Gilbert Y.},
	year = {1989},
	keywords = {Technology \& Engineering / General}
}

@book{achenbach_wave_2012,
	title = {Wave {Propagation} in {Elastic} {Solids}},
	isbn = {978-0-08-093471-6},
	abstract = {The propagation of mechanical disturbances in solids is of interest in many branches of the physical scienses and engineering. This book aims to present an account of the theory of wave propagation in elastic solids. The material is arranged to present an exposition of the basic concepts of mechanical wave propagation within a one-dimensional setting and a discussion of formal aspects of elastodynamic theory in three dimensions, followed by chapters expounding on typical wave propagation phenomena, such as radiation, reflection, refraction, propagation in waveguides, and diffraction. The treatment necessarily involves considerable mathematical analysis. The pertinent mathematical techniques are, however, discussed at some length.},
	language = {en},
	publisher = {Elsevier},
	author = {Achenbach, Jan},
	month = dec,
	year = {2012},
	keywords = {Science / Mechanics / Dynamics, Science / Mechanics / General, Science / Mechanics / Solids, Science / Physics / General, Technology \& Engineering / Mechanical}
}

@book{rose_basic_1979,
	address = {New York},
	title = {Basic {Physics} in {Diagnostic} {Ultrasound}},
	isbn = {978-0-471-05735-2},
	language = {English},
	publisher = {John Wiley \& Sons Inc},
	author = {Rose, Joseph L. and Goldberg, Barry B.},
	month = nov,
	year = {1979}
}

@article{ennis_microstructural_1997,
	title = {Microstructural stability and creep rupture strength of the martensitic steel {P}92 for advanced power plant},
	volume = {45},
	issn = {1359-6454},
	url = {http://www.sciencedirect.com/science/article/pii/S1359645497001766},
	doi = {10.1016/S1359-6454(97)00176-6},
	abstract = {Japanese 9\% Cr steel containing 0.5\% Mo and 1.8\% W (P92) has been investigated. Quantitative microstructural analyses using TEM of thin foils and extraction double replicas have been carried out after different austenitization and tempering treatments and after creep deformation at 600 and 650°C. Statistical quantitative analyses were undertaken to determine the dislocation density within the martensite laths, the width of the martensite laths/subgrains and the size and distribution of the carbide and carbonitride precipitates. Correlation of the results of the microstructural investigation with the creep rupture properties allowed the stability of the microstructure during the high temperature exposure to be assessed. The consequences of microstructural changes for the extrapolation of creep rupture data to design lifetimes are considered. Taking into account the strengthening mechanisms which remain effective in long term testing, the 100000 h stress rupture strength of P92 at 600°C is estimated at 115 MPa.},
	number = {12},
	urldate = {2015-05-18},
	journal = {Acta Materialia},
	author = {Ennis, P. J. and Zielinska-Lipiec, A. and Wachter, O. and Czyrska-Filemonowicz, A.},
	month = dec,
	year = {1997},
	pages = {4901--4907},
	file = {ScienceDirect Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\F57HIU2I\\Ennis et al. - 1997 - Microstructural stability and creep rupture streng.pdf:application/pdf;ScienceDirect Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\ATPRIE7T\\S1359645497001766.html:text/html}
}

@article{klueh_ferritic/martensitic_2007,
	series = {Nuclear {Fuels} and {Structural} {Materials} 1 {Proceedings} of the {First} {Symposium} on {Nuclear} {Fuels} and {Structural} {Materials} for {Next} {Generation} {Nuclear} {Reactors}},
	title = {Ferritic/martensitic steels for next-generation reactors},
	volume = {371},
	issn = {0022-3115},
	url = {http://www.sciencedirect.com/science/article/pii/S0022311507007398},
	doi = {10.1016/j.jnucmat.2007.05.005},
	abstract = {Concepts for the next generation of nuclear power reactors designed to meet increasing world-wide demand for energy include water-cooled, gas-cooled, and liquid-metal-cooled reactors. Reactor conditions for several designs offer challenges for engineers and designers concerning which structural and cladding materials to use. Depending on operating conditions, some of the designs favor the use of elevated-temperature ferritic/martensitic steels for in-core and out-of core applications. This class of commercial steels has been investigated in previous work on international fast reactor and fusion reactor research programs. More recently, international fusion reactor research programs have developed and tested elevated-temperature reduced-activation steels. Steels from these fission and fusion programs will provide reference materials for future fission applications. In addition, new elevated-temperature steels have been developed in recent years for conventional power systems that also need to be considered for the next generation of nuclear reactors.},
	number = {1–3},
	urldate = {2015-05-18},
	journal = {Journal of Nuclear Materials},
	author = {Klueh, R. L. and Nelson, A. T.},
	month = sep,
	year = {2007},
	pages = {37--52},
	file = {ScienceDirect Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\BJ2HS9MK\\Klueh and Nelson - 2007 - Ferriticmartensitic steels for next-generation re.pdf:application/pdf;ScienceDirect Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\4R9F8A2S\\S0022311507007398.html:text/html}
}

@book{boresi_advanced_1993,
	title = {Advanced mechanics of materials},
	volume = {5},
	publisher = {Wiley New York},
	author = {Boresi, Arthur Peter and Schmidt, Richard Joseph and Sidebottom, Omar M},
	year = {1993}
}

@book{graff_wave_2012,
	title = {Wave {Motion} in {Elastic} {Solids}},
	isbn = {978-0-486-13957-9},
	abstract = {Comprehensive, self-contained coverage of a variety of topics ranges from the elementary theory of waves and vibrations in strings to three-dimensional theory of waves in thick plates. Emphasis on analytical and experimental results, in addition to theoretical development. Appendices contain introductory material on elasticity, transforms, experimental techniques. Over 100 problems.},
	language = {en},
	publisher = {Courier Corporation},
	author = {Graff, Karl F.},
	month = apr,
	year = {2012},
	keywords = {Science / Physics / General, Technology \& Engineering / Civil / General}
}

@inproceedings{cunningham_ultrasonic_2012,
	title = {Ultrasonic wave propagation in heterogenous media},
	url = {https://pure.strath.ac.uk/portal/en/publications/ultrasonic-wave-propagation-in-heterogenous-media(a491f2b4-cb53-4eee-b627-e6380a4c6d1b).html},
	language = {English},
	urldate = {2015-03-14},
	booktitle = {Proceedings of {Acoustics}},
	author = {Cunningham, Laura and Mulholland, Anthony and Harvey, G. and Bird, C.},
	year = {2012},
	file = {Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\7BKJW3J4\\Cunningham et al. - 2012 - Ultrasonic wave propagation in heterogenous media.pdf:application/pdf;Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\QRAN4DMA\\ultrasonic-wave-propagation-in-heterogenous-media(a491f2b4-cb53-4eee-b627-e6380a4c6d1b).html:text/html}
}

@article{diboine_creep_1987,
	title = {Creep {Crack} {Initiation} and {Growth} in {Inconel} 718 {Alloy} at 650°c},
	volume = {10},
	issn = {1460-2695},
	url = {http://onlinelibrary.wiley.com/doi/10.1111/j.1460-2695.1987.tb01156.x/abstract},
	doi = {10.1111/j.1460-2695.1987.tb01156.x},
	abstract = {Creep cracking tests were performed on a nickel base superalloy, Inconel 718, using CT type specimens at 650°C in an air environment. Both time to initiate creep crack propagation (T1) and creep crack growth rate (ȧ) were measured as a function of the stress-intensity factor, K. It is shown that crack initiation behaviour and early crack growth (stage I) are strongly dependent on test procedures. Furthermore there is no unique correlation between ȧ and K, except in the regime corresponding to relatively high crack growth rates (stage II). This conclusion was reached by conducting tests both under increasing and under decreasing K. The reasons for this behaviour are briefly discussed in relation to environmental effects. A simple model (based upon a theoretical stress-strain field for creeping cracked solids and the ductility exhaustion concept) is used in an attempt to explain the results. The limitations for the application of this model are discussed. It is shown that this approach can explain a number of experimental results provided that it is accepted that creep ductility is time-dependent because of environmental effects. Finally, the results of these crack propagation tests are used in conjunction with the theoretical results derived from the Riedel and Rice analysis to model both crack initiation and crack growth behaviour of Inconel 718 under sustained load.},
	language = {en},
	number = {2},
	urldate = {2015-05-18},
	journal = {Fatigue \& Fracture of Engineering Materials \& Structures},
	author = {Diboine, A. and Pineau, A.},
	month = feb,
	year = {1987},
	pages = {141--151},
	file = {Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\PISP9ZV6\\Diboine and Pineau - 1987 - Creep Crack Initiation and Growth in Inconel 718 A.pdf:application/pdf;Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\GCPE73RZ\\abstract.html:text/html}
}

@misc{hayner_next_2004,
	title = {Next {Generation} {Nuclear} {Plant} {Materials} {Research} and {Development} {Program} {Plan}},
	url = {http://www5vip.inl.gov/technicalpublications/documents/3484392.pdf},
	urldate = {2015-05-18},
	publisher = {Idaho National Engineering and Environmental Laboratory},
	author = {Hayner, GO and Windes, WE},
	month = sep,
	year = {2004}
}

@inproceedings{sutcliffe_real-time_2012,
	title = {Real-time full matrix capture with auto-focusing of known geometry through dual layered media},
	url = {http://www.bindt.org/downloads/ndt2012_3a1.pdf},
	urldate = {2015-03-14},
	booktitle = {51st {Annual} {Conference} of {The} {British} {Institute} of {Non}-{Destructive} {Testing}},
	author = {Sutcliffe, Mark and Weston, Miles and Dutton, Ben and Cooper, Ian and Donne, Kelvin},
	year = {2012},
	file = {[PDF] from bindt.org:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\4ICK53J7\\Sutcliffe et al. - 2012 - Real-time full matrix capture with auto-focusing o.pdf:application/pdf}
}

@book{royer_elastic_2000,
	title = {Elastic {Waves} in {Solids} {II}: {Generation}, {Acousto}-optic {Interaction}, {Applications}},
	isbn = {978-3-540-65931-0},
	shorttitle = {Elastic {Waves} in {Solids} {II}},
	abstract = {Elastic waves possess some remarkable properties and it is these that explain their important role in the processing of electronic signals and the sensing of physical quantities. For example, they can be generated by localized or distributed sources, can propagate in the core or on the surface of optically transparent or opaque solids, have velocities one hundred thousand times less than those of electromagnetic waves, and they can modify the characteristics of a light beam. The purpose of this second volume is to illustrate the functions fulfilled by the free and guided waves described in Vol. I. It deals with the generation of bulk waves using piezoelectric resonators, generation of surface waves by interdigital transducers, interaction between elastic waves and light waves, acousto-electronic filters, acousto-optic components, sensors and instruments.},
	language = {en},
	publisher = {Springer Science \& Business Media},
	author = {Royer, Daniel and Dieulesaint, Eugene},
	month = jan,
	year = {2000},
	keywords = {Science / Acoustics \& Sound, Science / Physics / Condensed Matter, Science / Physics / General, Science / Physics / Mathematical \& Computational, Science / Physics / Optics \& Light, Science / Waves \& Wave Mechanics}
}

@article{rychlewski_hookes_1984,
	title = {On {Hooke}'s law},
	volume = {48},
	issn = {0021-8928},
	url = {http://www.sciencedirect.com/science/article/pii/0021892884901370},
	doi = {10.1016/0021-8928(84)90137-0},
	abstract = {A novel method of describing elastic anisotropy based on the concept of an elastic eigen state is proposed. The structure of the rigidity tensor is determined. In particular, it is shown that the set of 21 constants describing continuously the manifold of elastic solids is composed of three different subsystems: 6 true rigidity moduli, 12 dimensionless rigidity distributors, and 3 invariant parameters defining the orientation of the body in question relative to the laboratory system of coordinates. It is shown that Hooke's Law can be written uniquely for an arbitrary anisotropic body in the form of several laws describing the direct proportionality of the corresponding parts of the stress and deformation tensors. The construction of these parts is illustrated using an example of a transversally isotropic solid.},
	number = {3},
	urldate = {2015-05-18},
	journal = {Journal of Applied Mathematics and Mechanics},
	author = {Rychlewski, J.},
	year = {1984},
	pages = {303--314},
	file = {ScienceDirect Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\AT8EA7XK\\Rychlewski - 1984 - On Hooke's law.pdf:application/pdf;ScienceDirect Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\BBUN7PAR\\0021892884901370.html:text/html}
}

@article{masuyama_history_2001,
	title = {History of {Power} {Plants} and {Progress} in {Heat} {Resistant} {Steels}},
	volume = {41},
	doi = {10.2355/isijinternational.41.612},
	abstract = {During the last fifty years steam pressure and temperature in fossil-fired power plants have been continuously raised to improve thermal efficiency. Recent efforts for raising steam conditions are in response to the social demand for environmental protection as well as energy conservation concerns. Today the steam temperature of 600°C for modern power plants equipped with swing load or sliding pressure demand functions has already been realized, and a goal for the future is the 630°C to 650°C class with ferritic steels.However the 600°C to 630°C class is possible for current construction, based on already developed materials that include ferritic steels for pipework and rotors. Numerous studies on heat resistant steels actively conducted since the early 1970s have allowed great progress in both 9–12\% Cr steels and austenitic steels. This paper presents a historical view of developments in steam pressure and temperature of fossil-fired power plants and alloy design for heat resistant steels in the 20th century, particularly over the last severaldecades, as well as a survey of the current status of steel development for power plants, mainly with regard to creep strengthening and enhancement of corrosion resistance.},
	number = {6},
	journal = {ISIJ International},
	author = {Masuyama, Fujimitsu},
	year = {2001},
	keywords = {alloy design, austenite, boiler, creep strength, ferrite, heat resistant steel, power plant, turbine},
	pages = {612--625},
	file = {Jstage - Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\4QT8C6JU\\Masuyama - 2001 - History of Power Plants and Progress in Heat Resis.pdf:application/pdf}
}

@article{novikov_efficiency_1958,
	title = {The efficiency of atomic power stations (a review)},
	volume = {7},
	issn = {0891-3919},
	url = {http://www.sciencedirect.com/science/article/pii/0891391958902444},
	doi = {10.1016/0891-3919(58)90244-4},
	number = {1–2},
	urldate = {2015-05-18},
	journal = {Journal of Nuclear Energy},
	author = {Novikov, I. I.},
	month = aug,
	year = {1958},
	pages = {125--128},
	file = {ScienceDirect Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\RJN3WAJC\\Novikov - 1958 - The efficiency of atomic power stations (a review).pdf:application/pdf;ScienceDirect Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\Z6PRIIAZ\\0891391958902444.html:text/html}
}

@article{fjortoft_optimal_1998,
	title = {An optimal multiedge detector for {SAR} image segmentation},
	volume = {36},
	issn = {0196-2892},
	doi = {10.1109/36.673672},
	abstract = {Edge detection is a fundamental issue in image analysis. Due to the presence of speckle, which can be modeled as a strong, multiplicative noise, edge detection in synthetic aperture radar (SAR) images is extremely difficult, and edge detectors developed for optical images are inefficient. Several robust operators have been developed for the detection of isolated step edges in speckled images. The authors propose a new step-edge detector for SAR images, which is optimal in the minimum mean square error (MSSE) sense under a stochastic multiedge model. It computes a normalized ratio of exponentially weighted averages (ROEWA) on opposite sides of the central pixel. This is done in the horizontal and vertical direction, and the magnitude of the two components yields an edge strength map. Thresholding of the edge strength map by a modified version of the watershed algorithm and region merging to eliminate false edges complete an efficient segmentation scheme. Experimental results obtained from simulated SAR images as well as ERS-1 data are presented},
	number = {3},
	journal = {IEEE Transactions on Geoscience and Remote Sensing},
	author = {Fjortoft, R. and Lopes, A. and Marthon, P. and Cubero-Castan, E.},
	month = may,
	year = {1998},
	keywords = {adaptive optics, edge detection, edge detector, exponentially weighted average, geophysical measurement technique, geophysical signal processing, geophysical techniques, image analysis, Image edge detection, image segmentation, land surface, Laser radar, multiplicative noise, Optical detectors, Optical noise, optimal multiedge detector, Radar detection, radar imaging, radar remote sensing, remote sensing by radar, SAR, Speckle, step-edge detector, stochastic multiedge model, synthetic aperture radar, terrain mapping, Ultraviolet sources, watershed algorithm},
	pages = {793--802},
	file = {IEEE Xplore Abstract Record:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\ND8UIKTD\\abs_all.html:text/html;IEEE Xplore Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\DDGJPSFU\\Fjortoft et al. - 1998 - An optimal multiedge detector for SAR image segmen.pdf:application/pdf}
}

@article{simonetti_multiple_2006,
	title = {Multiple scattering: {The} key to unravel the subwavelength world from the far-field pattern of a scattered wave},
	volume = {73},
	shorttitle = {Multiple scattering},
	url = {http://link.aps.org/doi/10.1103/PhysRevE.73.036619},
	doi = {10.1103/PhysRevE.73.036619},
	abstract = {For more than a century the possibility of imaging the structure of a medium with diffracting wave fields has been limited by the tradeoff between resolution and imaging depth. While long wavelengths can penetrate deep into a medium, the resolution limit precludes the possibility of observing subwavelength structures. Near-field microscopy has recently demonstrated that the resolution limit can be overcome by bringing a probing sensor within one wavelength distance from the surface to be imaged. This paper extends the scope of near-field microscopy to the reconstruction of subwavelength structures from measurements performed in the far-field. It is shown that the distortion undergone by a wave field as it travels through an inhomogeneous medium and the subsequent generation of local evanescent fields encode subwavelength information in the far-field due to multiple scattering within the medium. This argument is proved theoretically and supported by a limited view experiment performed with elastic waves in which an image with a resolution better than a third of the wavelength is achieved.},
	number = {3},
	urldate = {2016-02-12},
	journal = {Physical Review E},
	author = {Simonetti, F.},
	month = mar,
	year = {2006},
	pages = {036619},
	file = {APS Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\4GVEJPF8\\PhysRevE.73.html:text/html;Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\IH78JXI2\\Simonetti - 2006 - Multiple scattering The key to unravel the subwav.pdf:application/pdf}
}

@incollection{sehgal_diffraction_1984,
	title = {Diffraction of {Ultrasound} by {Soft} {Tissues}:{The} {Inhomogeneous} {Continuous} {Model}},
	copyright = {©1984 Springer-Verlag US},
	isbn = {978-1-4612-9715-4 978-1-4613-2779-0},
	shorttitle = {Diffraction of {Ultrasound} by {Soft} {Tissues}},
	url = {http://link.springer.com/chapter/10.1007/978-1-4613-2779-0_19},
	abstract = {In this paper the theory of wave propagation in continuous- inhomogeneous media is utilized to explain scattering of ultrasound by soft tissues. When a number of scattering volume elements are present, as opposed to one, the scattered energy from a given volume element subsequently encounters other scattering volume elements. As a result of this, the sound energy is diffused instead of being propagated as well-defined waves. This means that the phase relationships are lost and the radiation becomes incoherent somewhat in the fashion described by Foldy15. If one were to freeze the ensemble to one instant and observe all the volume elements, each of them would appear as a secondary source emitting radiation in a different phase. Using this concept and assuming that soft tissues do not possess any sharp discontinuities, an equation for attenuation due to scattering is obtained which predicts a near linear frequency dependence for scattering-attenuation. The velocity fluctuations and correlation length for a variety of tissues are estimated from the values of scattering-attenuation using the postulated model. On the basis of these values, ray, Born, and Rytov approximations used to describe sound propagation through soft tissues, are evaluated.},
	language = {en},
	urldate = {2015-05-20},
	booktitle = {Acoustical {Imaging}},
	publisher = {Springer US},
	author = {Sehgal, C. M. and Greenleaf, J. F.},
	editor = {Kaveh, M. and Mueller, R. K. and Greenleaf, J. F.},
	year = {1984},
	keywords = {Physics, general},
	pages = {217--231},
	file = {Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\INUQPRWW\\10.html:text/html}
}

@misc{university_of_bristol_frequency_2011,
	title = {The {Frequency} {Domain}},
	author = {{University of Bristol}},
	month = nov,
	year = {2011}
}

@book{bracewell_fourier_2000,
	title = {The {Fourier} {Transform} and {Its} {Applications}},
	isbn = {978-0-07-303938-1},
	abstract = {This text is designed for use in a senior undergraduate or graduate level course in Fourier Transforms. This text differs from many other fourier transform books in its emphasis on applications. Bracewell applies mathematical concepts to the physical world throughout this text, equipping students to think about the world and physics in terms of transforms.The pedagogy in this classic text is excellent. The author has included such tools as the pictorial dictionary of transforms and bibliographic references. In addition, there are many excellent problems throughout this book, which are more than mathematical exercises, often requiring students to think in terms of specific situations or asking for educated opinions. To aid students further, discussions of many of the problems can be found at the end of the book.},
	language = {en},
	publisher = {McGraw Hill},
	author = {Bracewell, Ronald Newbold},
	year = {2000},
	keywords = {Mathematics / Mathematical Analysis}
}

@book{freegarde_introduction_2012,
	address = {Paris, France : Amsterdam},
	edition = {Pap/Psc edition},
	title = {Introduction to the {Physics} of {Waves}},
	isbn = {978-90-78677-10-9},
	abstract = {Balancing concise mathematical analysis with the real-world examples and practical applications that inspire students, this textbook provides a clear and approachable introduction to the physics of waves. The author shows through a broad approach how wave phenomena can be observed in a variety of physical situations and explains how their characteristics are linked to specific physical rules, from Maxwell's equations to Newton's laws of motion. Building on the logic and simple physics behind each phenomenon, the book draws on everyday, practical applications of wave phenomena, ranging from electromagnetism to oceanography, helping to engage students and connect core theory with practice. Mathematical derivations are kept brief and textual commentary provides a non-mathematical perspective. Optional sections provide more examples along with higher-level analyses and discussion. This textbook introduces the physics of wave phenomena in a refreshingly approachable way, making it ideal for first- and second-year undergraduate students in the physical sciences.},
	language = {English},
	publisher = {Cambridge University Press},
	author = {Freegarde, Tim},
	month = nov,
	year = {2012}
}

@book{baker_mathematical_2003,
	title = {The {Mathematical} {Theory} of {Huygens}' {Principle}},
	isbn = {978-0-8218-3478-7},
	abstract = {Baker and Copson originally set themselves the task of writing  a 
definitive text on partial differential equations in  mathematical 
physics. However, at the time, the subject was  changing rapidly and 
greatly, particularly via the developments  coming from quantum 
mechanics. Instead, the authors chose to  focus on a particular area of 
the broad theory, producing a  monograph complete in itself. The 
resulting book deals with  Huygens' principle in optics and its 
application to the theory  of diffraction. Baker and Copson concern 
themselves with the  general theory of the solution of the PDEs 
governing the  propagation of light. Extensive use is made of Green's 
method. A  chapter is dedicated to Sommerfeld's theory of diffraction,  
including diffraction of polarized light by a perfectly  reflecting 
half-plane and by a black half-plane. New material  was added for 
subsequent editions, notably Rayleigh's method of  integral equations to
 the problem of diffraction by a planar  screen. Some of the simpler 
diffraction problems are discussed  as examples. Baker and Copson's book
 quickly became the standard  reference on the subject of Huygens' 
principle. It remains so  today.},
	language = {en},
	publisher = {American Mathematical Soc.},
	author = {Baker, Bevan B. and Copson, E. T.},
	year = {2003},
	keywords = {Mathematics / Applied, Science / Waves \& Wave Mechanics}
}

@article{fukumoto_design_1981,
	title = {Design of {Ultrasound} {Transducers} {Using} {New} {Piezoelectric} {Ceramic} {Materials}},
	volume = {7},
	issn = {0301-5629},
	doi = {10.1016/0301-5629(81)90038-7},
	language = {English},
	number = {3},
	journal = {Ultrasound in Medicine and Biology},
	author = {Fukumoto, A. and Kawabuchi, M. and Sato, J.},
	year = {1981},
	pages = {275--281}
}

@article{harrington_sidelobe_1961,
	title = {Sidelobe reduction by nonuniform element spacing},
	volume = {9},
	issn = {0096-1973},
	doi = {10.1109/TAP.1961.1144961},
	abstract = {A perturbational procedure for reducing the sidelobe level of discrete linear arrays with uniform amplitude excitation by using nonuniform element spacing is presented. The calculation of the required element spacings is quite simple. The method can reduce the sidelobe level to about times the field intensity of the main lobe, where is the total number of elements, without increasing the beamwidth of the main lobe. Several examples are given.},
	number = {2},
	journal = {IRE Transactions on Antennas and Propagation},
	author = {Harrington, R.F.},
	month = mar,
	year = {1961},
	keywords = {Antenna arrays, Current distribution, Directive antennas, Feeds, Geometry, Gratings, Helium, Linear antenna arrays, Nonuniformly spaced arrays, Phased arrays, Radar applications},
	pages = {187--192},
	file = {IEEE Xplore Abstract Record:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\S36MHSMB\\articleDetails.html:text/html;IEEE Xplore Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\U8HNM7RR\\Harrington - 1961 - Sidelobe reduction by nonuniform element spacing.pdf:application/pdf}
}

@article{long_ultrasonic_2012,
	title = {Ultrasonic phased array inspection using full matrix capture},
	volume = {54},
	doi = {10.1784/insi.2012.54.7.380},
	abstract = {Work is being conducted to develop ultrasonic phased array inspection of stainless steel welded pipes with a completely undressed weld cap. The benefit of phased array inspection over single-crystal inspections is the ability to fire the array elements in a particular sequence (often termed a delay law) to steer and focus the beam, which allows multiple inspections to be conducted with a single transducer. Using a collection of different delay laws, conventional phased array controller software can generate a number of different types of image, such as plane and focused B-scan images as well as sector-scan images. When conducting an inspection we have chosen to collect the full matrix capture (FMC) of data, which involves the collection of the transmit-receive time domain signals from all element combinations, and post-process the data to form an image. The advantage of FMC is that it allows multiple inspections to be obtained from a single dataset, removes the dependence on phased array controller software for the processing of data and display of results, and allows more advanced processing algorithms that could not be applied to conventional data capture. This can improve the detection and characterisation of defects and hence improve safety; it also future-proofs inspection data, which can be archived and processed at a later date. This paper explains the FMC principle and describes the signal processing algorithms. The inspections were modelled using the CEA CIVA software and compared to experimental results.},
	number = {7},
	journal = {Insight - Non-Destructive Testing and Condition Monitoring},
	author = {Long, R and Russell, J and Cawley, P},
	month = jul,
	year = {2012},
	pages = {380--385}
}

@inproceedings{chatillon_simulation_2009,
	address = {Melville},
	title = {Simulation of {Advanced} {Ut} {Phased} {Array} {Techniques} with {Matrix} {Probes} and {Dynamic} {Settings} for {Complex} {Component} {Inspections}},
	volume = {1096},
	isbn = {978-0-7354-0629-2},
	abstract = {UT Phased arrays are now widely used in various industrial fields thanks to their inherent versatility compared to inspections carried out with standard probes. In addition to the adaptability to various inspection configurations (beam focusing and deflecting through arbitrary interfaces using modeled delay laws), the ever increasing number of channels in industrial acquisition systems and optimized 2D probes (matrix, sectorial patterns) allow designing new applications using the combination of electronic commutation (use of successive groups at transmission and reception scanned over the aperture of the array), multiple shots and multiple receptions (application of dynamic depth focusing laws). This paper presents new tools dedicated to matrix settings in terms of trajectories, multiple delay laws settings which have been recently gathered in the CIVA platform software. Those skills are illustrated with experimental and simulated configurations for complex inspection cases.},
	language = {English},
	booktitle = {Review of {Progress} in {Quantitative} {Nondestructive} {Evaluation}},
	publisher = {Amer Inst Physics},
	author = {Chatillon, S. and Mahaut, S. and Dubois, P.},
	editor = {Thompson, D. O. and Chimenti, D. E.},
	year = {2009},
	keywords = {model, Phased arrays, Reconstruction, Scattering, UT Simulation},
	pages = {864--871}
}

@article{banerjee_elastic_2006,
	title = {Elastic wave propagation in sinusoidally corrugated waveguides},
	volume = {119},
	issn = {0001-4966},
	doi = {10.1121/1.2172170},
	abstract = {The ultrasonic wave propagation in sinusoidally corrugated waveguides is studied in this paper. Periodically corrugated waveguides are gaining popularity in the field of vibration control and for designing structures with desired acoustic band gaps. Currently only numerical method (Boundary Element Method or Finite Element Method) based packages (e.g., PZFlex) are in principle capable of modeling ultrasonic fields in complex structures with rapid change of curvatures at the interfaces and boundaries but no analyses have been reported. However, the packages are very CPU intensive; it requires a huge amount of computation memory and time for its execution. In this paper a new semi-analytical technique called Distributed Point Source Method (DPSM) is used to model the ultrasonic field in sinusoidally corrugated waveguides immersed in water where the interface curvature changes rapidly. DPSM results are compared with analytical solutions. It is found that when a narrow ultrasonic beam hits the corrugation peaks at an angle, the wave propagates in the backward direction in waveguides with high corrugation depth. However, in waveguides with small corrugation the wave propagates in the forward direction. The forward and backward propagation phenomenon is found to be independent of the signal frequency and depends on the degree of corrugation. (c) 2006 Acoustical Society of America.},
	language = {English},
	number = {4},
	journal = {Journal of the Acoustical Society of America},
	author = {Banerjee, S. and Kundu, T.},
	month = apr,
	year = {2006},
	keywords = {acoustic pressure, anisotropic media, computation, diffraction, interface, piston, superposition, surfaces, transducer   field, ultrasonic sensors},
	pages = {2006--2017}
}

@article{ali_signal_2008,
	title = {Signal processing overview of ultrasound systems for medical imaging},
	url = {http://cdn.medicexchange.com/images/whitepaper/signal-processing-overview-of-ultrasound-systems.pdf},
	urldate = {2016-02-25},
	journal = {SPRAB12, Texas Instruments, Texas},
	author = {Ali, Murtaza and Magee, Dave and Dasgupta, Udayan},
	year = {2008},
	file = {[PDF] from medicexchange.com:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\CFUM7ZQ8\\Ali et al. - 2008 - Signal processing overview of ultrasound systems f.pdf:application/pdf}
}

@inproceedings{dobson_finite_2016,
	title = {Finite element analysis simulations for ultrasonic array {NDE} inspections},
	volume = {1706},
	url = {http://scitation.aip.org/content/aip/proceeding/aipcp/10.1063/1.4940499},
	doi = {10.1063/1.4940499},
	abstract = {Advances in manufacturing techniques and materials have led to an increase in the demand for reliable and robust inspection techniques to maintain safety critical features. The application of modelling methods to develop and evaluate inspections is becoming an essential tool for the NDE community. Current analytical methods are inadequate for simulation of arbitrary components and heterogeneous materials, such as anisotropic welds or composite structures. Finite element analysis software (FEA), such as PZFlex, can provide the ability to simulate the inspection of these arrangements, providing the ability to economically prototype and evaluate improved NDE methods. FEA is often seen as computationally expensive for ultrasound problems however, advances in computing power have made it a more viable tool. This paper aims to illustrate the capability of appropriate FEA to produce accurate simulations of ultrasonic array inspections – minimizing the requirement for expensive test-piece fabrication. Validation is afforded via corroboration of the FE derived and experimentally generated data sets for a test-block comprising 1D and 2D defects. The modelling approach is extended to consider the more troublesome aspects of heterogeneous materials where defect dimensions can be of the same length scale as the grain structure. The model is used to facilitate the implementation of new ultrasonic array inspection methods for such materials. This is exemplified by considering the simulation of ultrasonic NDE in a weld structure in order to assess new approaches to imaging such structures.},
	urldate = {2016-02-25},
	booktitle = {{AIP} {Conference} {Proceedings}},
	publisher = {AIP Publishing},
	author = {Dobson, Jeff and Tweedie, Andrew and Harvey, Gerald and O’Leary, Richard and Mulholland, Anthony and Tant, Katherine and Gachagan, Anthony},
	month = feb,
	year = {2016},
	keywords = {composite materials, Field emitters, Finite element methods, ultrasonic testing, Ultrasonography},
	pages = {040005},
	file = {Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\RI9FMBH5\\Dobson et al. - 2016 - Finite element analysis simulations for ultrasonic.pdf:application/pdf;Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\RGJPEKXZ\\1.html:text/html}
}

@inproceedings{russell_development_2010,
	title = {Development of a {Membrane} {Coupled} {Conformable} {Phased} {Array} {Inspection} {Capability}},
	volume = {1211},
	isbn = {0094-243X},
	url = {http://adsabs.harvard.edu/abs/2010AIPC.1211..831R},
	doi = {10.1063/1.3362497},
	abstract = {A membrane coupled conformable phased array device is under development 
to improve the inspection of components with irregular surface geometry.
This device uses a conventional linear phased array, which is coupled to
the surface of the component under test via a water path encapsulated by
a low loss rubber membrane. The membrane coupled device has recently
been updated to provide improved beam forming, reduced internal noise
and an integrated irrigation system. An enhanced inspection system is
under development that allows the rapid acquisition and processing of
scanned full matrix capture (FMC) inspection data. Results from a
challenging inspection of an austenitic component are provided
demonstrating how the membrane coupled phased array device can be used
to detect defects where other techniques cannot be used.},
	urldate = {2016-02-25},
	booktitle = {Review of {Progress} in {Quantitative} {Nondestructive} {Evaluation}: {Volume} 29},
	author = {Russell, J. and Long, R. and Cawley, P.},
	month = feb,
	year = {2010},
	keywords = {acoustical devices for the generation and reproduction of sound, Joining, Nondestructive testing: ultrasonic testing photoacoustic testing, Transduction, ultrasonic effects, Ultrasonic transducers, welding},
	pages = {831--838}
}

@book{vives_piezoelectric_2013,
	title = {Piezoelectric {Transducers} and {Applications}},
	isbn = {978-3-662-05361-4},
	abstract = {Piezoelectric Transducers and Applications provides a guide for graduate students and researchers to the current state of the art of this complex and multidisciplinary area. The book fills an urgent need for a unified source of information on piezoelectric devices and their astounding variety of existing and emerging applications. Some of the chapters focus more on the basic concepts of the different disciplines involved and are presented in a didactic manner. Others go deeper into the complex aspects of specific fields of research, thus reaching the technical level of a scientific paper. Among other topics resonant sensors, especially bulk acoustic wave thickness shear mode resonators, chemical and bio-sensors, as well as broadband ultrasonic systems are treated in-depth.},
	language = {en},
	publisher = {Springer Science \& Business Media},
	author = {Vives, Antonio Arnau},
	month = mar,
	year = {2013},
	keywords = {Technology \& Engineering / Automation, Technology \& Engineering / Electrical, Technology \& Engineering / Electronics / General, Technology \& Engineering / Materials Science, Technology \& Engineering / Nanotechnology \& MEMS}
}

@article{yiu_gpu-based_2011,
	title = {{GPU}-based beamformer: {Fast} realization of plane wave compounding and synthetic aperture imaging},
	volume = {58},
	issn = {0885-3010},
	shorttitle = {{GPU}-based beamformer},
	doi = {10.1109/TUFFC.2011.1999},
	abstract = {Although they show potential to improve ultrasound image quality, plane wave (PW) compounding and synthetic aperture (SA) imaging are computationally demanding and are known to be challenging to implement in real-time. In this work, we have developed a novel beamformer architecture with the real-time parallel processing capacity needed to enable fast realization of PW compounding and SA imaging. The beamformer hardware comprises an array of graphics processing units (GPUs) that are hosted within the same computer workstation. Their parallel computational resources are controlled by a pixel-based software processor that includes the operations of analytic signal conversion, delay-and-sum beamforming, and recursive compounding as required to generate images from the channel-domain data samples acquired using PW compounding and SA imaging principles. When using two GTX-480 GPUs for beamforming and one GTX-470 GPU for recursive compounding, the beamformer can compute compounded 512 × 255 pixel PW and SA images at throughputs of over 4700 fps and 3000 fps, respectively, for imaging depths of 5 cm and 15 cm (32 receive channels, 40 MHz sampling rate). Its processing capacity can be further increased if additional GPUs or more advanced models of GPU are used.},
	number = {8},
	journal = {IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control},
	author = {Yiu, B. Y. S. and Tsang, I. K. H. and Yu, A. C. H.},
	month = aug,
	year = {2011},
	keywords = {analytic signal conversion, Apertures, Arrays, array signal processing, beamformer architecture, beamformer hardware, biomedical transducers, biomedical ultrasonics, channel domain data samples, coprocessors, Delay, delay and sum beamforming, Firing, GPU array, GPU based beamformer, graphics processing units, GTX-470 GPU, GTX-480 GPU, Imaging, Instruction sets, medical image processing, parallel processing, pixel based software processor, plane wave compounding, real time parallel processing, Real time systems, recursive compounding, synthetic aperture imaging, ultrasonic transducer arrays, ultrasound image quality improvement},
	pages = {1698--1705},
	file = {IEEE Xplore Abstract Record:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\3V4VNNCU\\abs_all.html:text/html;IEEE Xplore Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\W384H9E5\\Yiu et al. - 2011 - GPU-based beamformer Fast realization of plane wa.pdf:application/pdf}
}

@misc{ nvidia_cuda_guide,
   author = {{ NVIDIA Corporation}},
   title = {{CUDA C Programming Guide}},
   year = "2015",
   url = "http://docs.nvidia.com/cuda/cuda-c-programming-guide",
   note = "[http://docs.nvidia.com/cuda/cuda-c-programming-guide; accessed 20-May-2015]"
 }

@misc{ wolfram_quintic,
   author = "Eric Weisstein",
   title = "Quintic Equation",
   year = "2004",
   url = "http://docs.nvidia.com/cuda/cuda-c-programming-guide",
   note = "[http://docs.nvidia.com/cuda/cuda-c-programming-guide; accessed 20-May-2015]"
 }
 
@misc{ rexolite_web,
   author = {{San Diego Plastics Inc.}},
   title = "Rexolite",
   year = "1996",
   url = "http://www.sdplastics.com/rexolite.html",
   note = "[http://www.sdplastics.com/rexolite.html; accessed 27-June-2015]"
 }
 
 @misc{ flex_web,
   author = {{Weidlinger Associates Inc.}},
   title = {{PZFlex}},
   year = "2014",
   url = "http://www.pzflex.com/",
   note = "[http://www.pzflex.com/; accessed 27-June-2015]"
 }
 
  @misc{ ultravision_web,
   author = {{Zetec Inc.}},
   title = {{UltraVision}},
   year = "2015",
   url = "http://ultravision.zetec.com/",
   note = "[http://ultravision.zetec.com/; accessed 27-June-2015]"
 }
 
  @misc{ civa_web,
   author = {{Commissariat \`a l'\'energie atomique et aux \'energies alternatives}},
   title = {{CIVA: solutions for NDT}},
   year = "2015",
   url = "http://www-civa.cea.fr/en/",
   note = "[http://www-civa.cea.fr/en/; accessed 27-June-2015]"
 }


@inproceedings{dillenz_progress_2001,
	title = {Progress in ultrasound phase thermography},
	volume = {4360},
	url = {http://dx.doi.org/10.1117/12.421042},
	doi = {10.1117/12.421042},
	abstract = {Ultrasound Phase Thermography (UPT) is a non-destructive technique derived from Ultrasound Lock-In Thermography (ULT) which was established a few years ago. UPT provides defect selective imaging using thermal waves generated by elastic waves. The use of short ultrasound bursts instead of sinusoidal signals for excitation allows for faster measurements and better reproducibility as compared to ULT. However, the advantages of phase images are the same: recognition of defect depth and suppression of temperature gradients. Application of UPT to typical defects of aircraft materials and components provide specific information on their nature.},
	urldate = {2015-05-18},
	author = {Dillenz, Alexander and Zweschper, Thomas and Busse, Gerhard},
	year = {2001},
	pages = {574--579}
}

@article{chen_enhancements_2008,
	title = {Enhancements of eddy current testing techniques for quantitative nondestructive testing of key structural components of nuclear power plants},
	volume = {238},
	issn = {0029-5493},
	url = {http://www.sciencedirect.com/science/article/pii/S0029549308000113},
	doi = {10.1016/j.nucengdes.2007.12.015},
	abstract = {In this paper, studies on upgrade of eddy current testing (ECT) techniques for inspection of stress corrosion cracks (SCC) in key structural components of a nuclear power plant are reported. Access and scanning vehicle (robot), advanced probes for steam generator (SG) tube inspection, developments and evaluations of new ECT probes for welding joint, and ECT-based crack sizing technique are described, respectively. Based on these techniques, it is demonstrated that ECT can play as a supplement of ultrasonic testing (UT) for the quantitative inspection of welding zone. It is also proved in this work that new ECT sensors are efficient even for inspection of a stainless steel plate as thick as 15 mm.},
	number = {7},
	urldate = {2015-05-18},
	journal = {Nuclear Engineering and Design},
	author = {Chen, Zhenmao and Yusa, Noritaka and Miya, Kenzo},
	month = jul,
	year = {2008},
	pages = {1651--1656},
	file = {ScienceDirect Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\GSN8KK54\\Chen et al. - 2008 - Enhancements of eddy current testing techniques fo.pdf:application/pdf;ScienceDirect Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\UCJDIJGZ\\S0029549308000113.html:text/html}
}

@article{avdelidis_aircraft_2004,
	title = {Aircraft composites assessment by means of transient thermal {NDT}},
	volume = {40},
	issn = {0376-0421},
	url = {http://www.sciencedirect.com/science/article/pii/S0376042104000193},
	doi = {10.1016/j.paerosci.2004.03.001},
	abstract = {The prerequisite for more competent and cost-effective aircraft has led to the evolution of innovative testing and evaluation procedures. Smart methods for assessing the integrity of an aircraft structure are essential to both reduce manufacturing costs and out-of-service time of aircraft due to maintenance. Nowadays, thermal non-destructive testing (NDT) is commonly used for assessing aircraft composites. In this work, certain applications of transient thermal NDT relating to the assessment of aircraft composites are presented. In particular, the following features were studied:

(a) Notches under multi-ply composite patching (bonded with FM73 adhesive film to the surface of Al 2024-T3) and a simulated delamination between two plies on a multi-ply composite repair.

(b) Drilling induced defects on multi-ply laminates of HEXCEL AS4/8552 carbon fibre composites.

(c) Impact damage on carbon fibre reinforced plastic (CFRP) panels and honeycomb sandwich structures (bonded with AF-163-2U.03 adhesive film).

(d) Through skin sensing assessment of CFRP.

Real-time monitoring of all features was obtained using pulsed thermography. However, in the composite repairs cases thermal modelling and pulsed-phase thermography were also used with the intention of providing supplementary results, whilst in the case of through skin imaging thermal modelling was also used in order to demonstrate the importance of thermal contact resistance between two surfaces (skin and strut). The thermal NDT approaches used in this work gave satisfactory results in all instances.},
	number = {3},
	urldate = {2015-05-18},
	journal = {Progress in Aerospace Sciences},
	author = {Avdelidis, N. P. and Almond, D. P. and Dobbinson, A. and Hawtin, B. C. and Ibarra-Castanedo, C. and Maldague, X.},
	month = apr,
	year = {2004},
	pages = {143--162},
	file = {ScienceDirect Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\MXI8SSH9\\Avdelidis et al. - 2004 - Aircraft composites assessment by means of transie.pdf:application/pdf;ScienceDirect Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\ABUGGCFR\\S0376042104000193.html:text/html}
}

@article{ciang_structural_2008,
	title = {Structural health monitoring for a wind turbine system: a review of damage detection methods},
	volume = {19},
	issn = {0957-0233},
	shorttitle = {Structural health monitoring for a wind turbine system},
	url = {http://iopscience.iop.org/0957-0233/19/12/122001},
	doi = {10.1088/0957-0233/19/12/122001},
	abstract = {Renewable energy sources have gained much attention due to the recent energy crisis and the urge to get clean energy. Among the main options being studied, wind energy is a strong contender because of its reliability due to the maturity of the technology, good infrastructure and relative cost competitiveness. In order to harvest wind energy more efficiently, the size of wind turbines has become physically larger, making maintenance and repair works difficult. In order to improve safety considerations, to minimize down time, to lower the frequency of sudden breakdowns and associated huge maintenance and logistic costs and to provide reliable power generation, the wind turbines must be monitored from time to time to ensure that they are in good condition. Among all the monitoring systems, the structural health monitoring (SHM) system is of primary importance because it is the structure that provides the integrity of the system. SHM systems and the related non-destructive test and evaluation methods are discussed in this review. As many of the methods function on local damage, the types of damage that occur commonly in relation to wind turbines, as well as the damage hot spots, are also included in this review.},
	language = {en},
	number = {12},
	urldate = {2015-05-18},
	journal = {Measurement Science and Technology},
	author = {Ciang, Chia Chen and Lee, Jung-Ryul and Bang, Hyung-Joon},
	month = dec,
	year = {2008},
	pages = {122001},
	file = {Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\ZDWQ35JH\\Ciang et al. - 2008 - Structural health monitoring for a wind turbine sy.pdf:application/pdf;Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\TGBFH2KN\\122001.html:text/html}
}

@article{siqueira_use_2004,
	title = {The use of ultrasonic guided waves and wavelets analysis in pipe inspection},
	volume = {41},
	issn = {0041-624X},
	url = {http://www.sciencedirect.com/science/article/pii/S0041624X04001246},
	doi = {10.1016/j.ultras.2004.02.013},
	abstract = {One of the main applications of guided waves is for pipe inspection, since its one-dimensional geometry allows inspecting long distances in a short time. As with most configurations (frequency, thickness) ultrasonic waves with many modes of propagation are generated, recent research focuses mostly on the generation and reception of specific modes, mainly by means of sophisticated arrays of transducers. In this paper this problem is addressed with a different approach, by processing ultrasonic signals with a low signal/noise ratio acquired with a single transducer in an pulse–echo configuration. In order to improve the evaluation of results, frequency bandpass filters and wavelet analysis were tested. Results showed that even when very noisy signals are utilized, signal processing improve the signal/noise (S/N) ratio up to 12 dB approximately and enhance the analysis of the results, thus demonstrating its usefulness.},
	number = {10},
	urldate = {2015-05-18},
	journal = {Ultrasonics},
	author = {Siqueira, M. H. S. and Gatts, C. E. N. and da Silva, R. R. and Rebello, J. M. A.},
	month = may,
	year = {2004},
	keywords = {Guided waves, Signal processing, Wavelets},
	pages = {785--797},
	file = {ScienceDirect Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\SZ6N6IQJ\\Siqueira et al. - 2004 - The use of ultrasonic guided waves and wavelets an.pdf:application/pdf;ScienceDirect Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\5HARXMRQ\\S0041624X04001246.html:text/html}
}

@article{goldberg_eddy_1998,
	title = {Eddy {Current} {Testing}, an {Emerging} {Ndt} {Method} for {Ferritic} {Weld} {Inspection}},
	volume = {56},
	url = {http://www.osti.gov/scitech/biblio/616171},
	language = {English},
	number = {2},
	urldate = {2015-05-18},
	journal = {Materials Evaluation},
	author = {Goldberg, L. O.},
	month = feb,
	year = {1998},
	keywords = {eddy current testing, in-service inspection, magnetic testing, natural gas, natural gas industry, offshore platforms, petroleum, petroleum industry, welded joints},
	file = {Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\BDACVX2U\\616171.html:text/html}
}

@techreport{naus_concrete_1986,
	title = {Concrete {Component} {Aging} and {Its} {Significance} {Relative} to {Life} {Extension} of {Nuclear} {Power} {Plants}},
	url = {http://www.osti.gov/scitech/biblio/5124169},
	language = {English},
	number = {NUREG/CR-4652; ORNL/TM-10059},
	urldate = {2015-05-18},
	institution = {Oak Ridge National Lab., TN (USA). Engineering Technology Div.},
	author = {Naus, D. J.},
	month = sep,
	year = {1986},
	keywords = {-- materials-- properties, -- materials-- radiation effects, -- power reactors, Aging, boiling water cooled, building materials, bwr type reactors, concretes, containment, containment systems, crack propagation, cracks, engineered safety systems, lifetime, light-water moderated, Materials, Materials Science, mechanical structures, nonboiling water cooled, nonbreeding, nuclear facilities, nuclear power plants, physical radiation effects, power plants, pwr type reactors, radiation effects, reactor components, reactor materials, reactors, specific nuclear reactors and associated plants, thermal power plants, water cooled reactors, water moderated reactors 210100*  -- power reactors},
	file = {Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\NMI5IDWQ\\5124169.html:text/html}
}

@article{lee_application_2010,
	series = {4th {International} {Topical} {Meeting} on {High} {Temperature} {Reactor} {Technology} ({HTR} 2008), with {Regular} {Papers}},
	title = {Application of ultrasonic wave propagation imaging method to automatic damage visualization of nuclear power plant pipeline},
	volume = {240},
	issn = {0029-5493},
	url = {http://www.sciencedirect.com/science/article/pii/S0029549310004309},
	doi = {10.1016/j.nucengdes.2010.06.011},
	abstract = {Hundreds of kilometers of pipeline, especially the elbows and welded joints in nuclear power plants (NPPs), are susceptible to aging and other types of damage. Therefore, the condition of a piping system requires regular inspection. We propose an automatic damage visualization technique using a laser ultrasonic scanning system and an ultrasonic wave propagation imaging (UWPI) method for the regular inspection process. Ultrasonic wave propagation movies (UWPMs) in thick and complex NPP pipes could be successfully visualized in a straight pipe with a crack, a welded pipe with multiple open and inner cracks at the welds, and an elbow pipe with wall thinning. A UWPM with ultrasonic time information could enable the discrimination of damage-induced wavefields from the wavefield not related to damage by providing the appearance time, source location, wavefront curvature, and propagation direction of the damage-induced wavefield. For the specimens tested, a 1 mm long crack in a 9 mm thick pipe could be localized regardless of the relative orientation of a sensor to the crack direction; 4 mm long 1.5 mm deep inner crack in a 4 mm thick welding bead could be detected despite the presence of the welding bead; wall thinning with gradual property variations could also be detected. In addition, since this method did not require laser focusing or reference data from the undamaged condition, and allows a large laser beam incident angle, it was very advantageous for the automatic scanning of the curved pipe surfaces. This study demonstrated that the proposed laser ultrasonic system equipped with the UWPI method is a useful inspection tool for NPP piping system management.},
	number = {10},
	urldate = {2015-05-18},
	journal = {Nuclear Engineering and Design},
	author = {Lee, Jung-Ryul and Jeong, Hyomi and Ciang, Chia Chen and Yoon, Dong-Jin and Lee, Seung-Suk},
	month = oct,
	year = {2010},
	pages = {3513--3520},
	file = {ScienceDirect Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\2UXN28RE\\Lee et al. - 2010 - Application of ultrasonic wave propagation imaging.pdf:application/pdf;ScienceDirect Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\D7WJKXRE\\S0029549310004309.html:text/html}
}

@techreport{mcnaughton_generic_1986,
	title = {Generic {Guidelines} for the {Life} {Extension} of {Fossil} {Fuel} {Power} {Plants}: {Final} {Report}},
	shorttitle = {Generic {Guidelines} for the {Life} {Extension} of {Fossil} {Fuel} {Power} {Plants}},
	url = {http://www.osti.gov/scitech/biblio/7174138},
	language = {English},
	number = {EPRI-CS-4778},
	urldate = {2015-05-18},
	institution = {Daedalus Associates, Inc., Mountain View, CA (USA); Delian Corp., Monroeville, PA (USA); Electric Power Research Inst., Palo Alto, CA (USA)},
	author = {McNaughton, W. P. and Richman, R. H. and Pillar, C. S. and Perry, L. W.},
	month = nov,
	year = {1986},
	keywords = {availability, electric generators, electric utilities, fossil-fueled power plants, fossil-fuel power plants, machinery, planning, power plants, public utilities, recommendations, risk assessment, service life, steam turbines, superheaters, thermal power plants, Turbines, turbomachinery 200100*  -- fossil-fueled power plants-- power plants \& power generation},
	file = {Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\89MAE68X\\7174138.html:text/html}
}

@article{su_guided_2006,
	title = {Guided {Lamb} waves for identification of damage in composite structures: {A} review},
	volume = {295},
	issn = {0022-460X},
	shorttitle = {Guided {Lamb} waves for identification of damage in composite structures},
	url = {http://www.sciencedirect.com/science/article/pii/S0022460X0600109X},
	doi = {10.1016/j.jsv.2006.01.020},
	abstract = {The guided Lamb wave is widely acknowledged as one of the most encouraging tools for quantitative identification of damage in composite structures, and relevant research has been conducted intensively since the 1980s. The main aim of this paper is to provide a comprehensive review on the state of the art of Lamb wave-based damage identification approaches for composite structures, addressing the advances and achievements in these techniques in the past decades. Major emphasis is placed on the unique characteristics and mechanisms of Lamb waves in laminated composites; approaches in wave mode selection, generation and collection; modelling and numerical simulation techniques; signal processing and identification algorithms; and sensor network technology for practical utility. Representative case studies are also briefly described in terms of various experimental validations and applications.},
	number = {3–5},
	urldate = {2015-05-18},
	journal = {Journal of Sound and Vibration},
	author = {Su, Zhongqing and Ye, Lin and Lu, Ye},
	month = aug,
	year = {2006},
	pages = {753--780},
	file = {ScienceDirect Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\WRG33JID\\Su et al. - 2006 - Guided Lamb waves for identification of damage in .pdf:application/pdf;ScienceDirect Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\6TZHPRBZ\\S0022460X0600109X.html:text/html}
}

@article{lavender_economic_1974,
	title = {The economic advantages of substituting ultrasonic for radiographic techniques},
	volume = {7},
	issn = {0029-1021},
	url = {http://www.sciencedirect.com/science/article/pii/0029102174900206},
	doi = {10.1016/0029-1021(74)90020-6},
	abstract = {The author argues that the replacement of radiography by ultrasonics does save cost and time with no loss of effectiveness. These savings, however, depend on thorough ndt techniques and proper support by a management conversant with the capabilities of ultrasonics. The author illustrates his argument with radiographic and ultrasonic examinations of a valve casting and concludes that the results have a general validity. From the general argument and this example he derives the conditions under which ultrasonics can safely replace radiography.},
	number = {1},
	urldate = {2015-05-18},
	journal = {Non-Destructive Testing},
	author = {Lavender, J. D.},
	month = feb,
	year = {1974},
	pages = {14--18},
	file = {ScienceDirect Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\WUWBBVNX\\Lavender - 1974 - The economic advantages of substituting ultrasonic.pdf:application/pdf;ScienceDirect Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\3MX4N3HG\\0029102174900206.html:text/html}
}


@article{murnaghan_compressibility_1944,
	title = {The {Compressibility} of {Media} under {Extreme} {Pressures}},
	volume = {30},
	issn = {0027-8424},
	url = {http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1078704/},
	number = {9},
	urldate = {2015-05-18},
	journal = {Proceedings of the National Academy of Sciences of the United States of America},
	author = {Murnaghan, F. D.},
	month = sep,
	year = {1944},
	pmid = {16588651},
	pmcid = {PMC1078704},
	pages = {244--247}
}

@inproceedings{grandia_nde_1995,
	title = {{NDE} applications of air-coupled ultrasonic transducers},
	volume = {1},
	doi = {10.1109/ULTSYM.1995.495667},
	abstract = {In recent years, several new NDE applications of air-coupled, as opposed to liquid-coupled, ultrasonics have been seriously pursued. The applications range from through transmission testing of aerospace laminates and various honeycomb or foam filled materials, and solar cells, to pulse-echo flaw detection in plastic electronic packaging materials and in-line inspection of large-diameter gas pipelines. Most of the new applications have been made possible by major advances in component technologies: transducers, preamplifiers, pulsers, signal-conditioning, and impedance matching and noise-matching circuits. In this paper, we describe the transducer types and circuit topologies that are especially suitable for applications in the 20 kHz to 20 MHz frequency region. We also address the important key differences between air-coupled and liquid-coupled inspection configurations. In particular, we focus on the practical advantages and limitations that arise from the fact that gases and liquids exhibit substantially different specific densities and sound speeds},
	booktitle = {, 1995 {IEEE} {Ultrasonics} {Symposium}, 1995. {Proceedings}},
	author = {Grandia, W.A. and Fortunko, C.M.},
	month = nov,
	year = {1995},
	keywords = {20 kHz to 20 MHz, Aerospace electronics, Aerospace materials, Aerospace testing, air-coupled ultrasonic transducers, circuit topologies, electro-acoustic air transducer types, Electronic equipment testing, electrostatic devices, electrostatic transducer, electrostrictive transducer, flaw detection, impedance matching circuits, in-line inspection, inspection, Laminates, large-diameter gas pipelines, liquid-coupled inspection configurations, magnetostrictive devices, magnetostrictive transducer, Materials testing, moving coil transducer, NDE applications, noise-matching circuits, Photovoltaic cells, piezoelectric transducer, piezoelectric transducers, plastic electronic packaging materials, Plastics, preamplifiers, pulse-echo flaw detection, pulsers, signal-conditioning, sound speeds, specific densities, ultrasonic materials testing, Ultrasonic transducers, variable reluctance},
	pages = {697--709 vol.1}
}

@article{wu_reflection_1990,
	title = {Reflection and transmission of elastic waves from a fluid‐saturated porous solid boundary},
	volume = {87},
	issn = {0001-4966},
	url = {http://scitation.aip.org/content/asa/journal/jasa/87/6/10.1121/1.399081},
	doi = {10.1121/1.399081},
	abstract = {Based on the classical work of Biot [J. Acoust. Soc. Am. 2 8, 168 (1956)] which predicts that three different kinds of bulk waves may propagate in the fluid‐saturated porous solid, the wave equation is solved to determine the energy reflection and transmission coefficients of plane elastic waves at oblique incidence on an interface between a fluid and a fluid‐saturated porous solid. For this purpose, the necessary formalism of the energy equation, the Poynting energy flux vector, and the sound intensity of elastic waves in fluid‐saturated porous media are presented. Two general cases of mode conversion have been investigated: (1) The initial wave is incident from the fluid to the interface and generates three transmitted bulk waves in the fluid‐saturated porous solid, and (2) the initial wave is incident from the fluid‐saturated porous solid to the interface and generates three reflected bulk waves in the same medium. Furthermore, the transmission of sound through a fluid‐saturated porous solid plate immersed in fluid is calculated. Measurement of sound transmission through a porous plate was carried out using experimental techniques suggested by Plona [Appl. Phys. Lett. 3 6, 259 (1980)]. Good correlation between measured and calculated values of the angular behavior of the transmission coefficients for fast, shear, and slow waves was obtained after adjusting the theory for experimentally obtained attenuation.},
	number = {6},
	urldate = {2015-05-18},
	journal = {The Journal of the Acoustical Society of America},
	author = {Wu, Kunyu and Xue, Qiang and Adler, Laszlo},
	month = jun,
	year = {1990},
	keywords = {Acoustic transmission, Acoustic waves, Elastic waves, Solid media, transmission coefficient},
	pages = {2349--2358}
}

@book{ricardo_modern_2009,
	title = {A {Modern} {Introduction} to {Differential} {Equations}},
	isbn = {9780123859136},
	abstract = {A Modern Introduction to Differential Equations presents a solid yet highly accessible introduction to differential equations, developing the concepts from a dynamical systems perspective and employing technology to treat topics graphically, numerically and analytically. This text is designed to be appropriate for a wide variety of students and exists as a natural successor to any modern calculus sequence.  Ancillary list: * Online ISM- http://textbooks.elsevier.com/web/product\_details.aspx?isbn=9780123747464 * Online SSM- http://www.elsevierdirect.com/product.jsp?isbn=9780123747464 * Algorithmic Testing by Maple- http://www.elsevierdirect.com/product.jsp?isbn=9780123747464 * Sample content, Ebook- http://www.elsevierdirect.com/product.jsp?isbn=9780123747464 * Image collection- http://www.elsevierdirect.com/companion.jsp?ISBN=9780123747464- student friendly readability- assessible to the average student- early introduction of qualitative and numerical methods- large number of exercises taken from biology, chemistry, economics, physics and engineering - Exercises are labeled depending on difficulty/sophistication- Full ancillary package including; Instructors guide, student solutions manual and course management system- end of chapter summaries- group projects},
	language = {en},
	publisher = {Academic Press},
	author = {Ricardo, Henry J.},
	month = feb,
	year = {2009},
	keywords = {Mathematics / Differential Equations / General}
}

@book{sokolnikoff_mathematical_1956,
	title = {Mathematical theory of elasticity},
	volume = {83},
	publisher = {McGraw-Hill New York},
	author = {Sokolnikoff, Ivan Stephen and Specht, Robert Dickerson},
	year = {1956}
}

@article{krause_comparison_1997,
	series = {Non-{Destructive} {Testing} in {Civil} {Engineering}},
	title = {Comparison of pulse-echo methods for testing concrete},
	volume = {30},
	issn = {0963-8695},
	url = {http://www.sciencedirect.com/science/article/pii/S0963869596000564},
	doi = {10.1016/S0963-8695(96)00056-4},
	abstract = {Pulse-echo methods (radar, impact-echo, ultrasonic impulse-echo) and simulation of wave propagation are applied for testing concrete speciments with metal ducts. The results of nondestructive testing of the same specimens by nine workgroups are described and compared. The research aims for the experiments are thickness measurement, location of a metal duct and of voided regions inside the duct. The results show the remarkable progress achieved in the past few years: the thickness and location of a duct could be measured for one specimen with great precision. In some cases voided regions in the duct could be located.},
	number = {4},
	urldate = {2015-05-18},
	journal = {NDT \& E International},
	author = {Krause, M. and Bärmann, M. and Frielinghaus, R. and Kretzschmar, F. and Kroggel, O. and Langenberg, K. J. and Maierhofer, C. and Müller, W. and Neisecke, J. and Schickert, M. and Schmitz, V. and Wiggenhauser, H. and Wollbold, F.},
	month = aug,
	year = {1997},
	keywords = {impact-echo, radar, ultrasonic echo},
	pages = {195--204}
}

@article{hughes_second-order_1953,
	title = {Second-{Order} {Elastic} {Deformation} of {Solids}},
	volume = {92},
	url = {http://link.aps.org/doi/10.1103/PhysRev.92.1145},
	doi = {10.1103/PhysRev.92.1145},
	abstract = {Expressions for the velocities of elastic waves in stressed solids are derived using Murnaghan's theory of finite deformations and third-order terms in the energy. For isotropic materials, in addition to the Lamé constants λ and μ, three additional constants, l, m, and n, are required to describe the material.},
	number = {5},
	urldate = {2015-05-18},
	journal = {Physical Review},
	author = {Hughes, D. S. and Kelly, J. L.},
	month = dec,
	year = {1953},
	pages = {1145--1149}
}

@article{alvarez-arenas_acoustic_2004,
	title = {Acoustic impedance matching of piezoelectric transducers to the air},
	volume = {51},
	issn = {0885-3010},
	doi = {10.1109/TUFFC.2004.1320834},
	abstract = {The purpose of this work is threefold: to investigate material requirements to produce impedance matching layers for air-coupled piezoelectric transducers, to identify materials that meet these requirements, and to propose the best solution to produce air-coupled piezoelectric transducers for the low megahertz frequency range. Toward this end, design criteria for the matching layers and possible configurations are reviewed. Among the several factors that affect the efficiency of the matching layer, the importance of attenuation is pointed out. A standard characterization procedure is applied to a wide collection of candidate materials to produce matching layers. In particular, some types of filtration membranes are studied. From these results, the best materials are identified, and the better matching configuration is proposed. Four pairs of air-coupled piezoelectric transducers also are produced to illustrate the performance of the proposed solution. The lowest two-way insertion loss figure is -24 dB obtained at 0.45 MHz. This increases for higher frequency transducers up to -42 dB at 1.8 MHz and -50 at 2.25 MHz. Typical bandwidth is about 15-20\%.},
	number = {5},
	journal = {IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control},
	author = {Alvarez-Arenas, T.E.G.},
	month = may,
	year = {2004},
	keywords = {acoustic impedance, acoustic transducers, air-coupled piezoelectric transducers, Attenuation, Bandwidth, Biomembranes, design criteria, Filtration, filtration membranes, Frequency, Impedance matching, impedance matching layers, Insertion loss, piezoelectric materials, piezoelectric transducers, two-way insertion loss},
	pages = {624--633}
}

@article{huang_wave_2009,
	title = {Wave attenuation mechanism in an acoustic metamaterial with negative effective mass density},
	volume = {11},
	issn = {1367-2630},
	url = {http://iopscience.iop.org/1367-2630/11/1/013003},
	doi = {10.1088/1367-2630/11/1/013003},
	abstract = {The wave attenuation and energy transfer mechanisms of a metamaterial having a negative effective mass density are studied. The metamaterial considered is represented by a lattice system consisting of mass-in-mass units. The attenuation of wave amplitude for frequencies in the stop band is studied from the energy transfer point of view. It is found that most of the work done by the external force on the lattice system is stored by the internal mass if the forcing frequency is close to the local resonance frequency. However, the energy stored in the internal mass is only temporary; it is taken out by the external force in the form of negative work in a cyclic manner. This behavior is utilized to design metamaterials for preventing stress waves from passing them.},
	language = {en},
	number = {1},
	urldate = {2015-05-18},
	journal = {New Journal of Physics},
	author = {Huang, H. H. and Sun, C. T.},
	month = jan,
	year = {2009},
	pages = {013003}
}

@article{connolly_application_2009,
	title = {The application of {Fermat}'s principle for imaging anisotropic and inhomogeneous media with application to austenitic steel weld inspection},
	volume = {465},
	copyright = {© 2009 The Royal Society},
	issn = {1364-5021, 1471-2946},
	url = {http://rspa.royalsocietypublishing.org/content/465/2111/3401},
	doi = {10.1098/rspa.2009.0272},
	abstract = {Ultrasonic inspection in anisotropic and inhomogeneous media has long presented a challenge because of the complex steering of ultrasonic paths. An approach is presented in which the true geometry of a previously used austenitic steel weld model is distorted so that, from one viewing location, all ultrasound travels in straight lines with a constant isotropic velocity. The mapping from the real space to this distorted space is accomplished using Fermat’s theorem of least travel time applied through ray tracing. Applications specific to inspection design and data interpretation for manual ultrasonic inspection of welds in austenitic steel plates are given. Validation of some intermediate results is provided using finite element analysis.},
	language = {en},
	number = {2111},
	urldate = {2015-06-27},
	journal = {Proceedings of the Royal Society of London A: Mathematical, Physical and Engineering Sciences},
	author = {Connolly, George D. and Lowe, Michael J. S. and Temple, J. Andrew G. and Rokhlin, Stanislav I.},
	month = nov,
	year = {2009},
	pages = {3401--3423},
	file = {Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\ov0azdtq.default\\zotero\\storage\\KMHS85DT\\Connolly et al. - 2009 - The application of Fermat's principle for imaging .pdf:application/pdf;Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\ov0azdtq.default\\zotero\\storage\\CSAT6CZ5\\3401.html:text/html}
}


@inproceedings{lardner_new_2013,
	title = {A new speckle noise suppression technique using cross-correlation of array sub-apertures in ultrasonic {NDE} of coarse grain materials},
	volume = {1511},
	isbn = {0094-243X},
	url = {http://adsabs.harvard.edu/abs/2013AIPC.1511..865L},
	doi = {10.1063/1.4789135},
	abstract = {In ultrasonic NDE, materials with coarse grains are difficult to inspect 
because a significant portion of energy will be reflected by the grains
which cause speckle noise when imaging. Coarse grain materials are
widely used in industry therefore a suitable inspection technique must
be developed. This paper presents Spatially Averaged Sub-Array
Correlation Imaging (SASACI), an advanced method that reduces speckle
noise. SASACI was validated through comparison with the Total Focusing
Method. A mean noise reduction of over 20dB SNR was observed when
inspecting a highly scattering nickel alloy at 5MHz with a 128 element
array.},
	urldate = {2014-02-11},
	booktitle = {Review of Progress in Quantitative Non-Destructive Evaluation},
	author = {Lardner, T. and Li, M. and Gongzhang, R. and Gachagan, A.},
	month = jan,
	year = {2013},
	keywords = {acoustic noise, nickel alloys, Nondestructive testing: ultrasonic testing photoacoustic testing, Speckle, ultrasonic materials testing},
	pages = {865--871}
}

@inproceedings{gongzhang_robust_2012,
	title = {Robust defect detection in ultrasonic nondestructive evaluation ({NDE}) of difficult materials},
	doi = {10.1109/ULTSYM.2012.0116},
	abstract = {In this paper, we present a novel and flexible method for reliable and robust defect detection in difficult materials. It is well known in the literature that the interaction between ultrasonic beams and the insonified medium is a highly nonlinear process, which potentially exhibits distinctive frequency-dependent properties for defects and random reflectors with a degree of randomness. Instead of investigating the structure and pattern of the spectrum of an individual echo, the proposed method focuses on the distinction between the ensembles of defect signals and clutter noise. A training process is used to establish the statistical analysis, based on which a hypothesis test is then applied to received echoes to detect defects. The approach is expected to be adaptive to the material microstructure and characteristics due to the statistical training. Experiments with a 5MHz transducer on austenitic steel samples from a coal fired power station are conducted. Austenitic steel is highly scattering and attenuating, and the method demonstrates accurate and reliable defect detection. When applied to A-scan waveforms, the grain noise is significantly reduced while defect signals are enhanced, and the signal-to-noise ratio (SNR) is improved by about 20dB. As a result, the defect is more visible and can be readily identified in B-scan images. Initial results indicate that this method is robust and delivers good performance without additional calibration and compensation.},
	booktitle = {Ultrasonics {Symposium} ({IUS}), 2012 {IEEE} {International}},
	author = {Gongzhang, Rui and Li, Minghui and Lardner, T. and Gachagan, A.},
	month = oct,
	year = {2012},
	keywords = {Acoustics, A-scan waveforms, austenitic steel, austenitic steel samples, B-scan images, clutter noise, coal fired power station, defect detection, defects, defect signals, difficult materials, echo, Feature extraction, frequency 5 MHz, frequency-dependent properties, grain noise, hypothesis test, individual echo, insonified medium, material characteristics, material microstructure, Materials, NDE, noise, non-destructive evaluation, nonlinear process, random reflectors, Signal processing algorithms, Signal to noise ratio, signal-to-noise ratio, SNR, Speckle, spectrum pattern, spectrum structure, statistical analysis, statistical training, training process, ultrasonic beams, ultrasonic materials testing, ultrasonic measurement, ultrasonic nondestructive evaluation, ultrasound},
	pages = {467--470},
	file = {IEEE Xplore Abstract Record:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\FHVC3C9T\\Gongzhang et al. - 2012 - Robust defect detection in ultrasonic nondestructi.html:text/html;IEEE Xplore Full Text PDF:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\WC4BCHHH\\Gongzhang et al. - 2012 - Robust defect detection in ultrasonic nondestructi.pdf:application/pdf}
}

@inproceedings{dziewierz_design_2013,
	title = {A design methodology for 2{D} sparse {NDE} arrays using an efficient implementation of refracted-ray {TFM}},
	isbn = {978-1-4673-5686-2, 978-1-4673-5684-8},
	url = {http://www.ieeeexplore.net/xpl/articleDetails.jsp?tp=&arnumber=6725215&searchWithin%3DSearch_Index_Terms%3A.QT.acoustic+wave+transmission.QT.%26searchWithin%3Dlardner},
	doi = {10.1109/ULTSYM.2013.0035},
	urldate = {2014-04-17},
	booktitle = {Ultrasonics {Symposium} ({IUS}), 2013 {IEEE} {International}},
	publisher = {IEEE},
	author = {Dziewierz, Jerzy and Lardner, Timothy and Gachagan, Anthony},
	month = jul,
	year = {2013},
	pages = {136--138},
	file = {Untitled Attachment:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\DW9GURG9\\Dziewierz et al. - 2013 - A design methodology for 2D sparse NDE arrays usin.html:text/html}
}

@inproceedings{lardner_using_2014,
	title = {Using phase information to enhance speckle noise reduction in the ultrasonic {NDE} of coarse grain materials},
	volume = {1581},
	url = {http://scitation.aip.org/content/aip/proceeding/aipcp/10.1063/1.4864938},
	doi = {10.1063/1.4864938},
	abstract = {Materials with a coarse grain structure are becoming increasingly prevalent in industry due to their resilience to stress and corrosion. These materials are difficult to inspect with ultrasound because reflections from the grains lead to high noise levels which hinder the echoes of interest. Spatially Averaged Sub-Aperture Correlation Imaging (SASACI) is an advanced array beamforming technique that uses the cross-correlation between images from array sub-apertures to generate an image weighting matrix, in order to reduce noise levels. This paper presents a method inspired by SASACI to further improve imaging using phase information to refine focusing and reduce noise. A-scans from adjacent array elements are cross-correlated using both signal amplitude and phase to refine delay laws and minimize phase aberration. The phase-based and amplitude-based corrected images are used as inputs to a two-dimensional cross-correlation algorithm that will output a weighting matrix that can be applied to any conventional image. This approach was validated experimentally using a 5MHz array a coarse grained Inconel 625 step wedge, and compared to the Total Focusing Method (TFM). Initial results have seen SNR improvements of over 20dB compared to TFM, and a resolution that is much higher.},
	urldate = {2014-10-21},
	booktitle = {{AIP} {Conference} {Proceedings}},
	publisher = {AIP Publishing},
	author = {Lardner, Timothy and Li, Minghui and Gachagan, Anthony},
	month = feb,
	year = {2014},
	keywords = {Acoustic beamforming, Corrosion, Industrial inspection, Medical image noise, Optical aberrations},
	pages = {1061--1068},
	file = {Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\ZN9FSU4U\\1.html:text/html}
}

@inproceedings{mcgilp_inspection_2014,
	title = {Inspection design using 2{D} phased array, {TFM} and {cueMAP} software},
	volume = {1581},
	url = {http://scitation.aip.org/content/aip/proceeding/aipcp/10.1063/1.4864803},
	doi = {10.1063/1.4864803},
	abstract = {A simulation suite, cueMAP, has been developed to facilitate the design of inspection processes and sparse 2D array configurations. At the core of cueMAP is a Total Focusing Method (TFM) imaging algorithm that enables computer assisted design of ultrasonic inspection scenarios, including the design of bespoke array configurations to match the inspection criteria. This in-house developed TFM code allows for interactive evaluation of image quality indicators of ultrasonic imaging performance when utilizing a 2D phased array working in FMC/TFM mode. The cueMAP software uses a series of TFM images to build a map of resolution, contrast and sensitivity of imaging performance of a simulated reflector, swept across the inspection volume. The software takes into account probe properties, wedge or water standoff, and effects of specimen curvature. In the validation process of this new software package, two 2D arrays have been evaluated on 304n stainless steel samples, typical of the primary circuit in nuclear plants. Thick section samples have been inspected using a 1MHz 2D matrix array. Due to the processing efficiency of the software, the data collected from these array configurations has been used to investigate the influence sub-aperture operation on inspection performance.},
	urldate = {2014-10-21},
	booktitle = {{AIP} {Conference} {Proceedings}},
	publisher = {AIP Publishing},
	author = {McGilp, Ailidh and Dziewierz, Jerzy and Lardner, Tim and Mackersie, John and Gachagan, Anthony},
	month = feb,
	year = {2014},
	keywords = {Antenna arrays, Computer Simulation, Computer software, Testing procedures, Ultrasonography},
	pages = {65--71},
	file = {Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\W9I5E3PM\\1.html:text/html}
}

@inproceedings{gongzhang_robust_2014,
	title = {Robust frequency diversity based algorithm for clutter noise reduction of ultrasonic signals using multiple sub-spectrum phase coherence},
	url = {http://scitation.aip.org/content/aip/proceeding/aipcp/10.1063/1.4865062},
	doi = {10.1063/1.4865062},
	urldate = {2015-05-21},
	booktitle = {Proceedings of the 40th {Annual} {Review} of {Progress} in {Quantitative} {Nondestructive} {Evaluation}: {Incorporating} the 10th {International} {Conference} on {Barkhausen} {Noise} and {Micromagnetic} {Testing}},
	author = {Gongzhang, R. and Li, M. and Xiao, B. and Lardner, T. and Gachagan, A.},
	year = {2014},
	pages = {1948--1955}
}

@inproceedings{mcgilp_inspection_2015,
	address = {Manchester, UK},
	title = {Inspection of complex components using 2{D} arrays and {TFM}},
	booktitle = {53rd {Annual} {Conference} of the {British} {Institute} of {Non}-{Destructive} {Testing} ({NDT} 2014)},
	publisher = {Curran Associates, Inc.},
	author = {McGilp, Ailidh and Lardner, Timothy and Dziewierz, Jerzy and Gachagan, Anthony and Mackersie, John and Bird, Colin},
	month = jan,
	year = {2015}
}

@inproceedings{brown_automated_2015,
	title = {Automated full matrix capture for industrial processes},
	volume = {1650},
	url = {http://scitation.aip.org/content/aip/proceeding/aipcp/10.1063/1.4914824},
	doi = {10.1063/1.4914824},
	abstract = {Full matrix capture (FMC) ultrasound can be used to generate a permanent re-focusable record of data describing the geometry of a part; a valuable asset for an inspection process. FMC is a desirable acquisition mode for automated scanning of complex geometries, as it allows compensation for surface shape in post processing and application of the total focusing method. However, automating the delivery of such FMC inspection remains a significant challenge for real industrial processes due to the high data overhead associated with the ultrasonic acquisition. The benefits of NDE delivery using six-axis industrial robots are well versed when considering complex inspection geometries, but such an approach brings additional challenges to scanning speed and positional accuracy when combined with FMC inspection. This study outlines steps taken to optimize the scanning speed and data management of a process to scan the diffusion bonded membrane of a titanium test plate. A system combining a KUKA robotic arm and a reconfigurable FMC phased array controller is presented. The speed and data implications of different scanning methods are compared, and the impacts on data visualization quality are discussed with reference to this study. For the 0.5 m2 sample considered, typical acquisitions of 18 TB/m2 were measured for a triple back wall FMC acquisition, illustrating the challenge of combining high data throughput with acceptable scanning speeds.},
	urldate = {2015-05-21},
	booktitle = {{AIP} {Conference} {Proceedings}},
	publisher = {AIP Publishing},
	author = {Brown, Roy H. and Pierce, S. Gareth and Collison, Ian and Dutton, Ben and Dziewierz, Jerzy and Jackson, Joseph and Lardner, Timothy and MacLeod, Charles and Morozov, Maxim},
	month = mar,
	year = {2015},
	keywords = {Antenna arrays, Data management, Industrial inspection, Industrial processes, Robotics},
	pages = {1967--1976},
	file = {Snapshot:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\A8NJE47G\\1.html:text/html}
}


@inproceedings{jurado_fast_1998,
	title = {Fast 3{D} two-point ray tracing for travel-time tomography},
	volume = {3453},
	url = {http://dx.doi.org/10.1117/12.323296},
	doi = {10.1117/12.323296},
	abstract = {The determination of a correct subsurface velocity model is of strategic importance for seismic imaging of complex geologies by use of 3D prestack depth migration. To accomplish this task we have developed a 3D reflection tomography software (called jerry) that is designed to handle methods of realistic complexity and that is fast enough to allow practical 3D applications. We use a blocky representation of the subsurface with a B-Spline parametrization for interface geometries and for velocity distributions within layers. The forward problem of reflection tomography is formulated as a two-point ray tracing problem and is solved by a bending method based on Fermat's principle with an approximation of the actual ray geometry within a layer by a straight line. The C2 property of the model parametrization allows to calculate exact derivatives of the traveltime function with respect to the model and thus to calculate rays (trajectories that satisfy Fermat's principle) from initial trial trajectories. The trajectory initialization is based on Snell's law for transmission/reflection at interfaces and uses an iterative method to calculate the intersection point between straight rays and interfaces. The introduction of non-physical ghost interfaces allows to improve the ray path approximation and thus the accuracy of the calculated traveltimes.},
	urldate = {2014-10-02},
	booktitle = {Mathematical {Methods} in {Geophysical} {Imaging} {V}},
	author = {Jurado, Fabrice and Lailly, Patrick and Ehinger, Andreas},
	year = {1998},
	pages = {70--81}
}

@inproceedings{reverdy_advanced_2012,
	address = {Durban, South Africa},
	title = {Advanced {Ultrasonic} 2D {Phased}-{Array} {Probes}},
	booktitle = {18th {World} {Conference} on {Non}-{Destructive} {Testing}},
	author = {Reverdy, Frédéric and Ithurralde, G},
	year = {2012},
	file = {Advanced Ultrasonic 2D Phased-Array Probes - ResearchGate:C\:\\Users\\Tim\\AppData\\Roaming\\Zotero\\Zotero\\Profiles\\g3v9a55z.default\\zotero\\storage\\EWGQXZD3\\267202310_Advanced_Ultrasonic_2D_Phased-Array_Probes.html:text/html}
}

@engdthesis{mcgilp_adaptation_2016,
	title = {Adaptation of {TFM} for {Inspection} of {Complex} {Components}},
	school = {University of Strathclyde},
	author = {McGilp, Ailidh},
	month = jan,
	year = {2016}
}


@phdthesis{dziewierz_2d_2015,
	title = {2D ultrasonic phased arrays for quantitative characterisation of complex defects},
	abstract = {Ultrasonic inspection can be consideredas one of many ways the technical system - installation or vehicle - can be made economical and safe. Contemporary ultrasonic systems are capable of detecting a wide variety of mechanical defects and flaws that may or may not affect the operation of a given product. Ultrasonic testing techniques are widely accepted for quality control and material testing. Moreover, the technology is proven, well-understood and widely used. Upon detecting a flaw, a decision has to be made to ensure the component is fit for the purpose: is the flaw acceptable or is repair of the given part or its replacement? Here, 2D ultrasonic phased arrays hold promise to quickly deliver detailed, 3D resolved information about the extent and nature of the flaw. This information can then be used to develop and justify the technical and economic decision concerning the existing state of the product. In effect, an opportunity exists for significant cost savings by using ultrasonic 2D phased array systems for defect characterisation. The interest of the work is to establish a process of designing and manufacturing of piezoelectric, 2D phased array ultrasound probes for application in non-destructive evaluation of materials. Furthermore, implementation of practical signal processing method is investigated. In the first part of the work the sensor mechanical and electrical design is addressed. The properties of piezoelectric ceramic composite materials are studied. Detailed numerical models have been used to analyse conditions required for crafting materials of desirable properties. A novel technique has been demonstrated that allows design of well-behaved triangular cut piezoelectric composite., Built into a single array element (of hexagonal shape by taking 6 triangular pillars) this new composite exhibits properties comparable to a reference rectangular composite (sensitivity of 0.60nm/V for hexagonal, 0.62nm/V for square; and inter-element crosstalk of -21.2dB for hexagonal and -21.9dB for square element). This composite then allows building of compact, dense-layout 2D phased array transducers with hexagonal or sparse element layout. The benefits of hexagonal element layout over classic, rectangular layout have been analysed theoretically and showed to be beneficial. Importantly, using hexagonal elements enables increasing the aperture of individual array elements by approximately 10\% without the corresponding drop in acceptance angle. This in turn allows a commensurable rise in the sensitivity of the sensor or alternatively, reduction in array element count for a given overall array aperture by over 20\% without the corresponding drop in the image quality measurements/levels. In the second part of the work, the problem of high output impedance of the miniature ultrasonic sensor is addressed by means of an in-probe miniature signal conditioning circuit. This improved the response amplitude of the element by 36dB and shortened its impulse response by a factor of 1.6. The novelty and practical benefit in this case lies in the fact that no high power components are needed in the probe body. In the third part of this work, an emerging General-Purpose Graphics Processing Unit (GPGPU) computer architecture is considered for the opportunities it offers to rethink the implementation of algorithms typically used in ultrasonic signal processing. Single-way beamforming, and two-way TFM and PCF beamforming have been developed for execution on the new platform, and show increase in performance of over 930 times compared to CPU processor., This software platform has been further enhanced by a new approach to solving the refracted ray Time of Flight problem in a way that is particularly well suited for this architecture. This resulted in a further increase of performance, i.e. 56x over the best published result found in the literature. The unprecedented performance and low cost of this new approach enables industrial deployment of advanced beamforming methods, as well as building of practical CAD tools for engineering and education.},
	language = {eng},
	urldate = {2016-05-19},
	school = {University of Strathclyde},
	author = {Dziewierz, Jerzy},
	collaborator = {{University of Strathclyde. Dept. of Electronic and Electrical Engineering}},
	year = {2015}
}