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Comparison of amorphous selenium and mercuric iodide film for diagnostic x-ray imaging

IUMRS International Conference in Asia

作者： Park, Ji-Koon Kang, Sang-Sik Cho, Sung-Ho Kim, So-Yeong Son, Dae-Woong Shin, Jung-Wook Choi, Jang-Yong Chun, Byung-Kyu Nam, Sang-Hee Inje Univ Med Imaging Res Ctr Gimhae South Korea Inje Univ Radiat Image Lab Gimhae South Korea Inje Univ Dept Biomed Engn Gimhae South Korea Korean Food & Drug Adm Seoul South Korea Dept Radiol Sorabol Coll Gyongju South Korea

ISBN: (纸本)3908451310

In this paper, we present the imaging parameters and compare both mercuric iodide (HgI2) and amorphous selenium (a-Se) films. Using MCNPx code, we designed the film structure and its thickness for the optimized detector in the diagnostic x-ray range. The mercuric iodide film was formed by a wet binder process, while the amorphous selenium film was deposited by physical vapor deposition (PVD). These deposition methods are capable of being scaled up to sizes required in diagnostic imaging applications. The electronic properties are investigated using dark current, x-ray sensitivity and signal to noise ratio (SNR). From our results, the developed HgI2 film as an alternative to a-Se photoconductor, which is in practical use in flat panel x-ray imaging detector, will prove its usefulness in the future design and the optimization for various diagnostic modalities.

关键词： amorphous selenium mercuric iodide x-ray wet binder process

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Analysis of SATIR test for the qualification of high heat flux components: defect detection and classification by signal-to-noise ratio maximization

Analysis of SATIR test for the qualification of high heat fl...

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11th International Workshop on Plasma-Facing Materials and Components for Fusion applications

作者： Cismondi, F. xerri, B. Jauffret, C. Schlosser, J. Vignal, N. Durocher, A. CEA Cadarache EURATOM Assoc CEA CEA DSM DRFC F-13108 St Paul Les Durance France Univ Toulon & Var F-83957 La Garde France

Plasma facing components (PFC) in Tore Supra and W7x adopt the flat tile concept using carbon fibre composite (CFC) material for the plasma facing material. As the cooling structure is made of a copper alloy material (CuCrZr), the bonding technique between CFC tiles and CuCrZr is critical. Currently, a soft metallic compliant layer is interposed between the two;in such a way the significant thermal expansion mismatch between carbon and copper can be accomodated. The development of a reliable non-destructive inspection technique (NDT) for the bond, to be performed during the manufacturing process, is obviously of great importance. The SATIR ( infrared thermography) test bed operating at Commisariat a l'Energie Atomique (CEA) Cadarache performs this function using transient infrared thermography: the thermal excitation is realized in the cooling channel and the presence of a faulty tile is detected in the form of a delayed thermal response. With this technique, the evolution of the surface temperature of an inspected element was compared to that of a defined free-defect element, using the so-called DTref criterion ( maximum of the transient temperature difference). The defect detection capability of the SATIR test bed can be improved using signal processing methods. A first treatment based on spatial image autocorrelation allows a better localization of the bond defect. Moreover, the problem of detection and classification of random signals ( like the thin defect signature) can be solved maximizing the signal-to-noise ratio (SNR). Two filters maximizing this ratio were optimized: the stochastic matched filter (SMF) aims at defect detection, while the constrained SMF aims at defect classification. These methods assume that the second-order properties of the process at play are known, through covariance matrices. All these methods process the SATIR signal utilizing any free-defect element as reference signal. The tile temperature signal is either processed by itself or

关键词： Materials testing

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A bio-inspired vision front-end chip with spatio-temporal processing and adaptive image capture

A bio-inspired vision front-end chip with spatio-temporal pr...

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IEEE 18th International Conference Application-specific Systems, Architectures and Processors, ASAP07

作者： Domínguez-Matas, C.M. Carmona-Galán, R. Sánchez-Fernández, F.J. Cuadri, J. Rodríguez-Vázquez, A. Instituto de Microelectrónica de Sevilla-CNM-CSIC Avda. Reina Mercedes s/n 41012 Sevilla Spain AnaFocus Ltd. Seville Spain

ISBN: (纸本)1424410274

This paper presents an advanced CMOS imager with concurrent parallel processing for early-vision tasks. The network is arranged in two layers of 32×32 programmable mixed-signal elementary processors with programmable linear feedback and control masks and inter-layer connections for continuous-time cellular neural network dynamics. The ratio of the time constants of these layers is user selectable. There are also feedforward connections to a faster third layer, intended to combine of the outputs of the other two in parallel. We have employed a restricted set of weights, trading flexibility for robustness. It results in a more linear multiplier block and, consequently, a significant reduction of irregularities in the propagation of analog waves ought to asymmetric synapses. Also global and local adaptation to illumination conditions, both throughout the scene and from frame to frame, are implemented on-chip, making use of the available focal-plane processing capabilities. The predicted computing power per area and power consumption is amongst the largest reported, what renders this kind of devices as an efficient front-end for portable applications of artificial vision. © 2006 IEEE.

关键词： Continuous time systems

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Morphological enhancement of medical images in a logarithmic image environment toolbox

Morphological enhancement of medical images in a logarithmic...

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European signal processing Conference (EUSIPCO)

作者： Eugen Zaharescu Mathematics and Informatics Faculty “Ovidius” University of Constanta Constanta Romania

The logarithmic image processing (LIP) theory is a mathematical framework that provides a set of specific algebraic and functional operations and structures that are well adapted to the representation and processing of non-linear images, and more generally of non-linear signals, valued in a bounded intensity range. This very well structured theory determined us to use the logarithmic image representation in our approach for defining a new set of mathematical morphology operators based upon structuring elements with a variable geometrical shape or adaptative structuring elements. The purpose of this paper is to define and to analyze the new multiplicative logarithmic morphological operators used in medical image enhancement. Finally, the experimental results reveal that this method has wide potential areas of impact which may include: Digital x-ray, Digital Mammography, Computer Tomography Scans, Nuclear Magnetic Resonance imagery and Telemedicine applications.

关键词： Transforms Shape image processing Morphology Medical diagnostic imaging signal processing

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Interconnect Customization for a Coarse-grained Reconfigurable Fabric

Interconnect Customization for a Coarse-grained Reconfigurab...

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International Symposium on Parallel and Distributed processing (IPDPS)

作者： Gayatri Mehta Justin Stander Mustafa Baz Brady Hunsaker Alex K. Jones Electrical and Computer Engineering University of Pittsburgh USA Industrial Engineering University of Pittsburgh USA

This paper describes several system-level interconnection strategies for a coarse-grained reconfigurable fabric designed for low-energy hardware acceleration. A small, representative sub-graph for signal and image processing applications is used to predict the success of mapping larger applications onto the fabric device with these different interconnection strategies, which include 32:1, 8:1, 5:1, 4:1, 3553:1 (3:1, 5:1, 5:1, 3:1) and 355:1 (3:1, 5:1, 5:1) cardinalities. Three mapping techniques are presented and used to complete mappings onto several of these fabric instances including a mixed integer linear programming technique, a constraint programming approach, and a greedy heuristic. We present results for area (in number of required rows), power, delay, and energy as well as run times for mapping a set of signal and image processing benchmarks onto each of these interconnects. Our results indicate that the 5:1 interconnect provides the best overall results and does not require any additional hardware resources than the baseline 4:1 technique. When compared with other implementation strategies, the reconfigurable fabric energy consumption, using 5:1-based interconnect, is within 5-10x of a direct ASIC implementation, is 10x better than an Virtex II Pro FPGA and is 100x better than an Intel xScale processor.

关键词： Fabrics Hardware signal processing image processing signal mapping Integer linear programming Acceleration Mixed integer linear programming Delay Energy consumption

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3D-brain model software: A new interactive real-time graphics visualization for rat brain

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Workshops Bildverarbeitung fur die Medizin: Algorithmen - Systeme - Anwendungen, BVM 2007 - Workshop on image processing for Medicine: Algorithms - Systems - applications, BVM 2007

作者： Ovtscharoff Jr., W. Riedel, A. Kubisch, C. Stoyanov, S. Helmeke, C. Herzog, A. Michaelis, B. Braun, K. Department of Zoology/Developmental Neurobiology Otto-von-Guericke-University Magdeburg 39016 Magdeburg Germany Institute for Electronics Signal Processing and Communications Otto-von-Guericke-University Magdeburg 39016 Magdeburg Germany Department of Internal Medicine 1 University Hospital Heidelberg Germany

ISBN: (纸本)3540710906

The project's main goal is the development of an interactive 3D atlas, that allows detailed exploration of the rat brain as well as illustration of interactions and information flows between various brain structures. Compared to other software on the market, this tool will focus more on the specific needs of scientists and students. Simplicity of use is one of its keys features. Students and scientists should be able to easily manipulate and view data that the system provides. Especially scientists should be able to import or add results and compare or illustrate them within a unified framework. The software will run on normal consumer hardware and not require expensive workstations, so that students can use it for learning purposes at home, as well as scientists being able to add data from their regular work PCs. Despite not having high hardware requirements, it will make use of various visualization effects.

关键词： Students

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Toeplitz-Structured Compressed Sensing Matrices

Toeplitz-Structured Compressed Sensing Matrices

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IEEE/SP Workshop on Statistical signal processing (SSP)

作者： Waheed U. Bajwa Jarvis D. Haupt Gil M. Raz Stephen J. Wright Robert D. Nowak Department of Electrical and Computer Engineering University of Wisconsin Madison USA GMR Research and Technology Concord MA USA Mühendislik-Mimarlik Fakültesi Elektrik-Elektronik Müh.Böl. University of Wisconsin Madison USA

The problem of recovering a sparse signal x Rn from a relatively small number of its observations of the form y = Ax Rk, where A is a known matrix and k « n, has recently received a lot of attention under the rubric of compressed sensing (CS) and has applications in many areas of signal processing such as data cmpression, image processing, dimensionality reduction, etc. Recent work has established that if A is a random matrix with entries drawn independently from certain probability distributions then exact recovery of x from these observations can be guaranteed with high probability. In this paper, we show that Toeplitz-structured matrices with entries drawn independently from the same distributions are also sufficient to recover x from y with high probability, and we compare the performance of such matrices with that of fully independent and identically distributed ones. The use of Toeplitz matrices in CS applications has several potential advantages: (i) they require the generation of only O(n) independent random variables; (ii) multiplication with Toeplitz matrices can be efficiently implemented using fast Fourier transform, resulting in faster acquisition and reconstruction algorithms; and (iii) Toeplitz-structured matrices arise naturally in certain application areas such as system identification.

关键词： Compressed sensing signal processing Probability distribution Sparse matrices Data compression image processing System identification Gas insulated transmission lines Optical computing Random variables

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SAFT Applied to Anisotropic and Attenuative Materials Using Sparse Array Data and signal processing

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AIP Conference Proceedings 2007年第1期894卷 806-813页

作者： Martin Spies Hans Rieder Fraunhofer‐Institute for Nondestructive Testing (IZFP) University of Saarland Bldg. E 3.1 66123 Saarbrücken Germany

Improved SAFT imaging methodologies are discussed for the inspection of composite materials and coarse‐grained polycrystalline materials. The problem of unfavourable beam fields of conventional transducers, which occurs for specific elastic material properties, is solved by using a two‐dimensional array for beam focusing and steering. Additionally, redundant sets of rf‐data are acquired and used for image reconstruction by exciting the transmit and receive elements, respectively, in variable subsets, revealing the promising potential of sparse array applications.

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Architecture Design and VLSI Implementation of the Re-conf1gurable 2-D CAT/ICAT Chip for the applications of image Compression

Architecture Design and VLSI Implementation of the Re-conf1g...

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IEEE International Symposium on Consumer Electronics (ISCE)

作者： Rong-Jian Chen Wen-Kai Lu Jui-Lin Lai Department of Electronics Engineering National United University Miaoli Taiwan

Architecture design and VLSI implementation of the re-configurable 2-D CAT/ICAT chip for developing the CAT wavelets-based image coding system is presented in this paper. To facilitate the development of this CAT/ICAT chip, we firstly develop the evolution of CA to produce orthogonal 1-D CA bases; then we use the canonical product circuit to produce 2-D CA bases; finally, it utilizes input data and 2-D CA bases to produce 2-D CAT/ICAT coefficients. In order to enhance the flexibility of applications, we developed the re-configurable 2-D CAT/ICAT circuit to make the proposed chip to produce 2-D 4 x 4, 8 x 8, and 16 x 16 CAT/ICAT coefficients. Throughputs of the 2-D 8 x 8, and 16 x 16 CAT/ICAT coefficients are same as that of 2-D 4 x 4 CAT/ICAT coefficients due to the proposed re-configurable 2-D CAT/ICAT chip has highly parallel processing property. We have accomplished the circuit synthesis using the SYNOPSYS tolls with the UMC 0.18 um Cell-library. The chip size was 12.888 mm , and the maximum operation frequency was 111MHz with 851mW total dynamic power. It shows that the architecture of the proposed re-configurable 2-D CAT/ICAT chip is suitable for VLSI realization .

关键词： Very large scale integration image coding image storage Streaming media Fourier transforms Discrete cosine transforms image communication Propagation losses Network servers Web server

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Morphological Enhancement of Medical images in a Logarithmic image Environment

Morphological Enhancement of Medical Images in a Logarithmic...

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International Symposium on signals, Circuits and Systems (ISSCS)

作者： Eugen Zaharescu Mathematics and Informatics Faculty Ovidius University of Constanta Romania

关键词： Biomedical imaging image processing signal processing image representation Morphology Shape image analysis Magnetic analysis image enhancement x-ray imaging

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