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Development of correction methods for variable pinhole single-photon emission computed tomography

JOURNAL OF INSTRUMENTATION 2016年第2期11卷 C02060-C02060页

作者： Bae, S. Bae, J. Lee, H. Lee, K. Korea Univ Dept Bioconvergence Engn 145 Anam Ro Seoul South Korea Korea Univ Res Inst Global Hlth Technol 145 Anam Ro Seoul South Korea Korea Univ Sch Biomed Engn 145 Anam Ro Seoul South Korea

We propose a novel pinhole collimator in which the pinhole shape can be changed in real-time, and a new single-photon emission computed tomography (SPECT) system that utilizes this variable pinhole (VP) collimator. The acceptance angle and distance between the collimator and the object of VP SPECT are varied so that the optimum value of the region-of-interest (ROI) can be obtained for each rotation angle. Because of these geometrical variations, new correction methods are required for image reconstruction. In this study, we developed two correction methods. The first is the sensitivity-correction algorithm, which minimizes the variation of a system matrix caused by varying the acceptance angle for each rotation angle. The second is the acquisition-time-correction method, which reduces the variation of uniformity caused by varying the distance between the collimator and the object for each rotation angle. A 3D maximum likelihood expectation maximization (MLEM) algorithm was applied to image reconstruction, and two digital phantoms were studied to evaluate the resolution and sensitivity of the images obtained using the proposed methods. The images obtained by using the proposed correction methods show higher uniformity and resolution than those obtained without using these methods. In particular, the results of the resolution phantom study show that hot rods (0.8-mm-diameter) can be clearly distinguished using the proposed correction methods. A quantitative analysis of the ROI phantom revealed that the mean square error (MSE) was 0.42 without the acquisition-time-correction method, and 0.04 with the acquisition-time-correction method. The MSEs of the resolution phantom without and with the acquisition-time-correction method were calculated as 55.14 and 14.69, respectively.

关键词： data processing methods Gamma camera, SPECT, PET PET/CT, coronary CT angiography (CTA) Medical-image reconstruction methods and algorithms, computer-aided software

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Estimation of reliable range of electron temperature measurements with sets of given optical bandpass filters for KSTAR Thomson scattering system based on synthetic Thomson data

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JOURNAL OF INSTRUMENTATION 2017年第11期12卷

作者： Kim, K. -H. Oh, T. -S. Park, K. -R. Lee, J. H. Ghim, Y. -C. Korea Adv Inst Sci & Technol Dept Nucl & Quantum Engn Daejeon South Korea Natl Fus Res Inst Daejeon South Korea

One factor determining the reliability of measurements of electron temperature using a Thomson scattering (TS) system is transmittance of the optical bandpass filters in polychromators. We investigate the system performance as a function of electron temperature to determine reliable range of measurements for a given set of the optical bandpass filters. We show that such a reliability, i.e., both bias and random errors, can be obtained by building a forward model of the KSTAR TS system to generate synthetic TS data with the prescribed electron temperature and density profiles. The prescribed profiles are compared with the estimated ones to quantify both bias and random errors.

关键词： Analysis and statistical methods data processing methods Plasma diagnostics interferometry spectroscopy and imaging

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Feasibility study of direct spectra measurements for Thomson scattered signals for KSTAR fusion-grade plasmas

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JOURNAL OF INSTRUMENTATION 2017年第11期12卷

作者： Park, K. -R. Kim, K. -H. Kwak, S. Svensson, J. Lee, J. Ghim, Y. -C. Korea Adv Inst Sci & Technol Dept Nucl & Quantum Engn Daejeon South Korea Max Planck Inst Plasma Phys Teilinst Greifswald Greifswald Germany Natl Fus Res Inst Daejeon South Korea

Feasibility study of direct spectra measurements of Thomson scattered photons for fusion-grade plasmas is performed based on a forward model of the KSTAR Thomson scattering system. Expected spectra in the forward model are calculated based on Selden function including the relativistic polarization correction. Noise in the signal is modeled with photon noise and Gaussian electrical noise. Electron temperature and density are inferred using Bayesian probability theory. Based on bias error, full width at half maximum and entropy of posterior distributions, spectral measurements are found to be feasible. Comparisons between spectrometer-based and polychromator-based Thomson scattering systems are performed with varying quantum efficiency and electrical noise levels.

关键词： Analysis and statistical methods data processing methods Plasma diagnostics charged-particle spectroscopy Spectrometers

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Development of correction methods for variable pinhole single-photon emission computed tomography

Development of correction methods for variable pinhole singl...

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17th International Workshop on Radiation Imaging Detectors

关键词： data processing methods Gamma camera, SPECT, PET PET/CT, coronary CT angiography (CTA) Medical-image reconstruction methods and algorithms, computer-aided software

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On determining the prediction limits of mathematical models for time series

On determining the prediction limits of mathematical models ...

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4th International Conference on Frontiers in Diagnostics Technologies

作者： Peluso, E. Murari, A. Gelfusa, M. Lungaroni, M. Talebzadeh, S. Gaudio, P. Abhangi, M. Abreu, P. Aftanas, M. Afzal, M. Aggarwal, K. M. Aho-Mantila, L. Ahonen, E. Aints, M. Airila, M. Albanese, R. Alegre, D. Alessi, E. Aleynikov, P. Alfier, A. Alkseev, A. Allan, P. Almaviva, S. Alonso, A. Alper, B. Alsworth, I. Alves, D. Ambrosino, G. Ambrosino, R. Amosov, V. Andersson, F. Andersson Sunden, E. Angelone, M. Anghel, A. Anghel, M. Angioni, C. Appel, L. Apruzzese, G. Arena, P. Ariola, M. Arnichand, H. Arnoux, G. Arshad, S. Ash, A. Asp, E. Asunta, O. Atanasiu, C. V. Austin, Y. Avotina, L. Axton, M. D. Ayres, C. Bachmann, C. Baciero, A. Baiao, D. Bailescu, V. Baiocchi, B. Baker, A. Baker, R. A. Balboa, I. Balden, M. Balshaw, N. Bament, R. Banks, J. W. Baranov, Y. F. Barlow, I. L. Barnard, M. A. Barnes, D. Barnsley, R. Baron Wiechec, A. Baruzzo, M. Basiuk, V. Bassan, M. Bastow, R. Batista, A. Batistoni, P. Bauer, R. Bauvir, B. Bazylev, B. Beal, J. Beaumont, P. S. Becoulet, A. Bednarczyk, P. Bekris, N. Beldishevski, M. Bell, K. Belli, F. Bellinger, M. Belo, J. K. Belo, P. Belonohy, E. Benterman, N. A. Bergsaker, H. Bernardo, J. Bernert, M. Berry, M. Bertalot, L. Beurskens, M. N. A. Bieg, B. Bielecki, J. Biewer, T. Bigi, M. Bilkova, P. Binda, F. Bizarro, J. P. S. Bjorkas, C. Blackman, K. Blackman, T. R. Blanchard, P. Blanco, E. Blatchford, P. Bobkov, V. Boboc, A. Bodnar, G. Bogar, O. Bolzonella, T. Boncagni, L. Bonham, R. Bonheure, G. Boom, J. Booth, J. Borba, D. Borodin, D. Botrugno, A. Boulbe, C. Boulting, P. Bovert, K. V. Bowden, M. Bower, C. Boyce, T. Boyer, H. J. Bradshaw, J. M. A. Braic, V. Breizman, B. Bremond, S. Brennan, P. D. Brett, A. Brezinsek, S. Bright, M. D. J. Brix, M. Broeckx, W. Brombin, M. Brown, B. C. Brown, D. P. D. Brown, M. Bruno, E. Bucalossi, J. Buch, J. Buckley, M. A. Bucko, K. Budny, R. Bufferand, H. Bulman, M. Bulmer, N. Bunting, P. Buratti, P. Burcea, G. Burckhart, A. Buscarino, A. Butcher, P. R. Butler, N. K. Bykov, I. Byrne, J. Byszuk, A. Cackett, A. Cahyna, P. Cain, G. Calabro, G. Callaghan, Univ Roma Tor Vergata Dept Ind Engn Via Politecn 1 I-00133 Rome Italy Univ Padua Ist Nazl Fis Nucl Consorzio RFX CNRENEAAcciaierie Venete SpA Corso Stati Uniti 4 I-35127 Padua Italy EUROfus Consortium JET Culham Sci Ctr Abingdon OX14 3DB Oxon England Aalto Univ FIN-00076 Aalto Finland BCS Barcelona Spain Culham Sci Ctr CCFE Abingdon OX14 3DB Oxon England IRFM CEA F-13108 St Paul Les Durance France Ctr Brasileiro Pesquisas Fis BR-22290180 Rio De Janeiro Brazil Consorzio CREATE I-80125 Naples Italy Consorzio RFX I-35127 Padua Italy Daegu Univ Gyongsan 712174 Gyeongbuk South Korea Univ Carlos III Madrid Dept Fis Madrid 28911 Spain Univ Ghent Dept Appl Phys B-9000 Ghent Belgium Chalmers Univ Technol Dept Earth & Space Sci SE-41296 Gothenburg Sweden Univ Cagliari Dept Elect & Elect Engn I-09123 Cagliari Italy Comenius Univ Fac Math Phys & Informat Dept Expt Phys Bratislava 84248 Slovakia Univ Strathclyde Dept Phys & Appl Phys Glasgow G4 ONG Lanark Scotland Uppsala Univ Dept Phys & Astron SE-75120 Uppsala Sweden Lund Univ Dept Phys SE-22100 Lund Sweden KTH SCI Dept Phys SE-10691 Stockholm Sweden Univ Oxford Dept Phys Oxford OX1 2JD England Univ Warwick Dept Phys Coventry CV4 7AL W Midlands England Queens Univ Dept Pure & Appl Phys Belfast BT7 1NN Antrim North Ireland Univ Catania Dipartimento Ingn Elettr Elettr & Sistemi I-95125 Catania Italy Dublin City Univ Dublin Ireland CRPP EPFL CH-1015 Lausanne Switzerland CNRS UMR 7648 Ecole Polytech F-91128 Palaiseau France EUROfus Programme Management Unit D-85748 Garching Germany Culham Sci Ctr EUROfus Programme Management Unit Abingdon OX14 3DB Oxon England European Commiss B-1049 Brussels Belgium FOM Inst DIFFER NL-3430 BE Nieuwegein Netherlands Forsch Zentrum Julich GmbH Inst Energie & Klimaforsch Plasmaphys D-52425 Julich Germany Fus Energy Joint Undertaking Barcelona 08019 Spain KTH EES Fus Plasma Phys SE-10044 Stockholm Sweden Gen Atom San Diego CA 85608 USA IF

Prediction is one of the main objectives of scientific analysis and it refers to both modelling and forecasting. The determination of the limits of predictability is an important issue of both theoretical and practical relevance. In the case of modelling time series, reached a certain level in performance in either modelling or prediction, it is often important to assess whether all the information available in the data has been exploited or whether there are still margins for improvement of the tools being developed. In this paper, an information theoretic approach is proposed to address this issue and quantify the quality of the models and/or predictions. The excellent properties of the proposed indicator have been proved with the help of a systematic series of numerical tests and a concrete example of extreme relevance for nuclear fusion.

关键词： Analysis and statistical methods data processing methods Pattern recognition, cluster finding, calibration and fitting methods

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Waste processing: new near infrared technologies for material identification and selection

Waste processing: new near infrared technologies for materia...

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4th International Conference on Frontiers in Diagnostics Technologies

作者： Cesetti, M. Nicolosi, P. Univ Padua Dept Informat Engn Via G Gradenigo 6-b I-35131 Padua Italy PAL Srl Via Ind 6-B I-31047 Ponte Di Piave Italy

The awareness of environmental issues on a global scale increases the opportunities for waste handling companies. Recovery is set to become all the more important in areas such as waste selection, minerals processing, electronic scrap, metal and plastic recycling, refuse and the food industry. Effective recycling relies on effective sorting. Sorting is a fundamental step of the waste disposal/recovery process. The big players in the sorting market are pushing for the development of new technologies to cope with literally any type of waste. The purpose of this tutorial is to gain an understanding of waste management, frameworks, strategies, and components that are current and emerging in the field. A particular focus is given to spectroscopic techniques that pertains the material selection process with a greater emphasis placed on the NIR technology for material identification. Three different studies that make use of NIR technology are shown, they are an example of some of the possible applications and the excellent results that can be achieved with this technique.

关键词： data processing methods Imaging spectroscopy Pattern recognition cluster finding calibration and fitting methods

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Short- and long-range energy strategies for Japan and the world after the Fukushima nuclear accident

Short- and long-range energy strategies for Japan and the wo...

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17th International Symposium on Laser-Aided Plasma Diagnostics

作者： Muraoka, K. Wagner, F. Yamagata, Y. Donne, A. J. H. Plazwire Co Ltd 2-3-54 Higashi Naka Fukuoka 8120892 Japan Max Planck Inst Plasma Phys Wendelsteinstr 1 D-17491 Greifswald Germany Kyushu Univ 6-1 Kasuga Koen Kasuga Fukuoka 8168580 Japan EUROfusion Boltzmannstr 2 D-85748 Garching Germany

on energy policies in Japan and worldwide. This is particularly because it occurred at the time of the growing awareness of global warming forcing measures towards decarbonised energy production, namely the use of fossil fuels has to be drastically reduced from the present level of more than 80% by 2050. A dilemma has now emerged because nuclear power, a CO2-free technology with proven large-scale energy production capability, lost confidence in many societies, especially in Japan and Germany. As a consequence, there is a world-wide effort now to expand renewable energies (REs), specifically photo-voltaic (PV) and wind power. However, the authors conjecture that PV and wind power can provide only up to a 40% share of the electricity production as long as sufficient storage is not available. Beyond this level, the technological (high grid power) and economic problems (large surplus production) grow. This is the result of the analysis of the growing use of REs in the electricity systems for Germany and Japan. The key element to overcome this situation is to develop suitable energy storage technologies. This is particularly necessary when electricity will become the main energy source because also transportation, process heat and heating, will be supplied by it. Facing the difficulty in replacing all fossil fuels in all countries with different technology standards, a rapid development of carbon capture and storage (CCS) might also be necessary. Therefore, for the short-range strategy up to 2050, all meaningful options have to be developed. For the long-range strategy beyond 2050, new energy sources (such as thermonuclear fusion, solar fuels and nuclear power-if inherently safe concepts will gain credibility of societies again), and large-scale energy storage systems based on novel concepts (such as large-capacity batteries and hydrogen) is required. It is acknowledged that the prediction of the future is difficult;therefore, the only insurance in this situation is by

关键词： data processing methods Simulation methods and programs Analysis and statistical methods

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Determination of Total Volatile Basic Nitrogen (TVB-N) Content in Beef by Hyperspectral Imaging Technique

Determination of Total Volatile Basic Nitrogen (TVB-N) Conte...

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International Seminar on Applied Physics, Optoelectronics and Photonics (APOP)

作者： Liu, Shanmei Gan, Lu Huazhong Agr Univ Coll Informat Wuhan 430070 Peoples R China Wuhan Polytech Univ Sch Elect & Elect Engn Wuhan 430023 Peoples R China

Non-destructive determination of TVB-N content in beef using hyperspectral imaging (HSI) technique was evaluated. In order to create a robust model to predict the TVB-N content in beef, partition of sample set, spectral pretreatment, and the optimum wavelength selection were discussed. After the beef sample set was parted by concentration gradient (CG) algortithm, and the spectra of beef samples were preprocessed by standard normalized variate (SNV) combined with auto scale(AS), the partial least square regression (PLSR) model was established using the full spectral range, which had the best prediction abilities with R-cv(2) of 0.9124, R-p(2) of 0.8816, RMSECV of 1.5889, and RMSEP of 1.7719, respectively. After the optimum wavelengths which is closely related to the TVB-N content of beef samples was obtained using the competitive adaptive re weighted (CARS) algorithm, a new PLSR model was established using the optimum wavelengths, which had outstanding prediction abilities with R-cv(2) of 0.9235, Rp2 of 0.9241, RMSECV of 1.4881, and RMSEP of 1.4882, *** study showed that HSI is a powerful technique to predict the TVB-N content in beef by a nondestructive way.

关键词： beef TVB-N content hyperspectral imaging data processing methods

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Evaluation of spatial resolution in image acquisition by optical flatbed scanners for radiochromic film dosimetry

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JOURNAL OF INSTRUMENTATION 2016年第3期11卷 P03024-P03024页

作者： Asero, G. Greco, C. Gueli, A. M. Raffaele, L. Spampinato, S. Univ Catania Dipartimento Fis & Astron PH3DRA Labs PHys Dating Diagnost Dosimetry Res & Via Santa Sofia 64 I-95123 Catania Italy Ist Nazl Fis Nucl Via Santa Sofia 64 I-95123 Catania Italy Azienda Osped Univ Policlin Vittorio Emanuele Via Santa Sofia 78 I-95123 Catania Italy Univ Catania Scuola Fac Med Dipartimento Sci Med Chirurg & Tecnol Avanzate GF Scuola Specializzaz Fis Med Via Santa Sofia 78 I-95123 Catania Italy

Introduction: Radiochromic films are two-dimensional dosimeters that do not require developing and give values of absorbed dose with accuracy and precision. Since this dosimeter colours directly after irradiation, it can be digitized with commercial optical flatbed scanners to obtain a calibration curve that links blackening of the film with dose. Although the film has an intrinsic high spatial resolution, the scanner determines the actual resolution of this dosimeter, in particular the "dot per inch" (dpi) parameter. The present study investigates the effective spatial resolution of a scanner used for Gafchromic (R) XR-QA2 film (designed for radiology Quality Assurance) analysis. Material and methods: The quantitative evaluation of the resolution was performed with the Modulation Transfer Function (MTF) method, comparing the nominal resolution with the experimental one. The analysis was performed with two procedures. First, the 1951 USAF resolution test chart, a tool that tests the performance of optical devices, was used. Secondly, a combined system of mammography X-ray tube, XR-QA2 film and a bar pattern object was used. In both cases the MTF method has been applied and the results were compared. Results: The USAF and the film images have been acquired with increasing dpi and a standard protocol for radiochromic analysis, to evaluate horizontal and vertical and resolution. The effective resolution corresponds to the value of the MTF at 50%. In both cases and for both procedures, it was verified that, starting from a dpi value, the effective resolution saturates. Conclusion: The study found that, for dosimetric applications, the dpi of the scanner have to be adjusted to a reasonable value because, if too high, it requires high scanning and computational time without providing additional information.

关键词： Image reconstruction in medical imaging data processing methods Dosimetry concepts and apparatus X-ray radiography and digital radiography (DR)

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A resource-efficient adaptive Fourier analyzer

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JOURNAL OF INSTRUMENTATION 2016年第10期11卷 10014-10014页

作者： Hajdu, C. F. Zamantzas, C. Daboczi, T. European Org Nucl Res CERN Beams Dept 385 Route Meyrin CH-1217 Meyrin Switzerland Budapest Univ Technol & Econ Dept Measurement & Informat Syst Muegyet Rkp 3 H-1111 Budapest Hungary

We present a resource-efficient frequency adaptation method to complement the Fourier analyzer proposed by Peceli. The novel frequency adaptation scheme is based on the adaptive Fourier analyzer suggested by Nagy. The frequency adaptation method was elaborated with a view to realizing a detector connectivity check on an FPGA in a new beam loss monitoring (BLM) system, currently being developed for beam setup and machine protection of the particle accelerators at the European Organisation for Nuclear Research (CERN). The paper summarizes the Fourier analyzer to the extent relevant to this work and the basic principle of the related frequency adaptation methods. It then outlines the suggested new scheme, presents practical considerations for implementing it and underpins it with an example and the corresponding operational experience.

关键词： Control and monitor systems online data processing methods Detector control systems (detector and experiment monitoring and slow-control systems, architecture, hardware, algorithms, databases) Digital signal processing (DSP)

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