Pub Date : 1993-10-31DOI: 10.1109/NSSMIC.1993.701850
Z. Mu, A. Wexler
The reasons for the low resolution of the Electrical Impedance Computed Tomography(E1CT) algorithms have not been fully explored. Previous investigations focused on the dis- cussions of numerical features of an algorithm. This paper dis- cussed such problems by implementing Point-Accumulative Point-Iterative algorithms to multi-port resistive networks ac- cording to the similarities of the Finite Element method and lin- ear network analysis. The results indicate that improper mea- surement pattems in EICT can cause an EICT algorithm's failure although the number of independent measurements are still higher than the number of unknowns. With the help of graph theory, it is shown that the image quality of EICT is not only dependent on the numerical features of an EICT system, but also on its topological structure. An optimal excitationl measurement pattem algorithm in topological sense is then pro- posed. Successful simulations in the twociimensional field problems are performed. Suggestions to the three-dimensional applications of EICT are made based on the results from the multi-port resistive network recovery.
{"title":"Electrical Impedance Computed Tomography -algorithms And Applications","authors":"Z. Mu, A. Wexler","doi":"10.1109/NSSMIC.1993.701850","DOIUrl":"https://doi.org/10.1109/NSSMIC.1993.701850","url":null,"abstract":"The reasons for the low resolution of the Electrical Impedance Computed Tomography(E1CT) algorithms have not been fully explored. Previous investigations focused on the dis- cussions of numerical features of an algorithm. This paper dis- cussed such problems by implementing Point-Accumulative Point-Iterative algorithms to multi-port resistive networks ac- cording to the similarities of the Finite Element method and lin- ear network analysis. The results indicate that improper mea- surement pattems in EICT can cause an EICT algorithm's failure although the number of independent measurements are still higher than the number of unknowns. With the help of graph theory, it is shown that the image quality of EICT is not only dependent on the numerical features of an EICT system, but also on its topological structure. An optimal excitationl measurement pattem algorithm in topological sense is then pro- posed. Successful simulations in the twociimensional field problems are performed. Suggestions to the three-dimensional applications of EICT are made based on the results from the multi-port resistive network recovery.","PeriodicalId":287813,"journal":{"name":"1993 IEEE Conference Record Nuclear Science Symposium and Medical Imaging Conference","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124528139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1993-10-31DOI: 10.1109/NSSMIC.1993.701662
M. Bosetti, C. Furetta, C. Leroy, S. Pensotti, P. Rancoita, M. Rattaggi, M. Redaelli, M. Rizzatti, A. Seidman, G. Terzi
Float-Zone (FZ) and Magnetic-Czochralski (MCZ) silicon detectors were irradiated with fast neutron fluences larger than 1013n/cm2). The charge collection efficiency I ef f ) dependence on reverse bias voltage (VB) and on fluence (a) were investigated for both types of detectors. The (eff) dependence on VB, for FZ and MCZ detectors, shows that the relation between charge carrier concentration and full depletion voltage does not obey the standard equation for an unsymmetrical step junction. eff is found to have a logarithmic dependence on 0 for both types of detectors.
{"title":"Systematic Investigation Of The Neutron Irradiation Effects On The Performances Of FZ And MCZ Silicon Detectors","authors":"M. Bosetti, C. Furetta, C. Leroy, S. Pensotti, P. Rancoita, M. Rattaggi, M. Redaelli, M. Rizzatti, A. Seidman, G. Terzi","doi":"10.1109/NSSMIC.1993.701662","DOIUrl":"https://doi.org/10.1109/NSSMIC.1993.701662","url":null,"abstract":"Float-Zone (FZ) and Magnetic-Czochralski (MCZ) silicon detectors were irradiated with fast neutron fluences larger than 1013n/cm2). The charge collection efficiency I ef f ) dependence on reverse bias voltage (VB) and on fluence (a) were investigated for both types of detectors. The (eff) dependence on VB, for FZ and MCZ detectors, shows that the relation between charge carrier concentration and full depletion voltage does not obey the standard equation for an unsymmetrical step junction. eff is found to have a logarithmic dependence on 0 for both types of detectors.","PeriodicalId":287813,"journal":{"name":"1993 IEEE Conference Record Nuclear Science Symposium and Medical Imaging Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127673932","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1993-10-31DOI: 10.1109/NSSMIC.1993.701692
K. Endo, Y. Ohsawa, W. Zhou, T. Yamagishi
{"title":"50 Hz Power Supply For B-factory Booster Synchrotron","authors":"K. Endo, Y. Ohsawa, W. Zhou, T. Yamagishi","doi":"10.1109/NSSMIC.1993.701692","DOIUrl":"https://doi.org/10.1109/NSSMIC.1993.701692","url":null,"abstract":"","PeriodicalId":287813,"journal":{"name":"1993 IEEE Conference Record Nuclear Science Symposium and Medical Imaging Conference","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128158991","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1993-10-31DOI: 10.1109/NSSMIC.1993.373589
F. Pedersen, M. Bergstrom, E. Bengtsson, E. Maripuu
Principal component analysis (PCA) is a data-driven technique used to explain the variance-covariance structure of a data set. PCA of noisy image data can be expected to be hard to perform properly, since PCA has no way to discriminate between variance due to signals and variance due to noise. Further, PCA call not discriminate between pixels belonging to the background and pixels belonging to the object(s). The authors show that PCA of gamma camera and positron emission tomography (PET) images can be significantly improved by taking the noise and spatial background into consideration. The two applications represent two fundamentally different noise problems, namely large background noise and signal dependent noise. The problems are illustrated using a synthetic image and a methodology for exploring the feature space called multivariate image analysis (MIA). After defining the problems, a methodology for handling the noise is proposed. The preprocessing which is proposed is equivalent to expressing pixels according to their significance levels.<>
{"title":"Principal component analysis of dynamic PET and gamma camera images: a methodology to visualize the signals in the presence of large noise","authors":"F. Pedersen, M. Bergstrom, E. Bengtsson, E. Maripuu","doi":"10.1109/NSSMIC.1993.373589","DOIUrl":"https://doi.org/10.1109/NSSMIC.1993.373589","url":null,"abstract":"Principal component analysis (PCA) is a data-driven technique used to explain the variance-covariance structure of a data set. PCA of noisy image data can be expected to be hard to perform properly, since PCA has no way to discriminate between variance due to signals and variance due to noise. Further, PCA call not discriminate between pixels belonging to the background and pixels belonging to the object(s). The authors show that PCA of gamma camera and positron emission tomography (PET) images can be significantly improved by taking the noise and spatial background into consideration. The two applications represent two fundamentally different noise problems, namely large background noise and signal dependent noise. The problems are illustrated using a synthetic image and a methodology for exploring the feature space called multivariate image analysis (MIA). After defining the problems, a methodology for handling the noise is proposed. The preprocessing which is proposed is equivalent to expressing pixels according to their significance levels.<<ETX>>","PeriodicalId":287813,"journal":{"name":"1993 IEEE Conference Record Nuclear Science Symposium and Medical Imaging Conference","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132525812","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1993-10-31DOI: 10.1109/NSSMIC.1993.701739
B. Grinev
INTRODUCTION At the first sight a detector is not a complicated optical system: a scintillator optically coupled with glass, enveloped in a light reflecting coating and as a rule hermetically packed in a housing. But in practice several different optical and constructional materials are combined in a detector. Depending on operational requirements when selecting the materials there arise technical contradictions due to the difference in the physical properties. Elimination of these contradictions leads to the appearance of new solutions in other fields of science and engineering, obtaining new materials. The application of the scintillation detectors in geophysical research (radioactive logging of deep wells, aerial survey etc.) defines the demands to their ability to operate in a wide temperature range, high sensitivity and efficiency of the registration of the ionizing radiation, resistance to mechanical loadings 111. The increase of sensitivity and efficiency of y-radiation registration is complicated by the limitations in diameter of the detector and can be achieved only by increasing the height of the scintillator or using the scintillation materials with a higher atomic number. Utilization of conventional scintillators (A B , complex oxides etc.) for this purpose is at present problematic due to the difficulties in obtaining crystals of necessary size, high light output, good transparency to the intrinsic radiation, high thermal resistance. I1 VI
{"title":"Principles Of The Creation Of Scintillation Detectors For Severe Operation Conditions","authors":"B. Grinev","doi":"10.1109/NSSMIC.1993.701739","DOIUrl":"https://doi.org/10.1109/NSSMIC.1993.701739","url":null,"abstract":"INTRODUCTION At the first sight a detector is not a complicated optical system: a scintillator optically coupled with glass, enveloped in a light reflecting coating and as a rule hermetically packed in a housing. But in practice several different optical and constructional materials are combined in a detector. Depending on operational requirements when selecting the materials there arise technical contradictions due to the difference in the physical properties. Elimination of these contradictions leads to the appearance of new solutions in other fields of science and engineering, obtaining new materials. The application of the scintillation detectors in geophysical research (radioactive logging of deep wells, aerial survey etc.) defines the demands to their ability to operate in a wide temperature range, high sensitivity and efficiency of the registration of the ionizing radiation, resistance to mechanical loadings 111. The increase of sensitivity and efficiency of y-radiation registration is complicated by the limitations in diameter of the detector and can be achieved only by increasing the height of the scintillator or using the scintillation materials with a higher atomic number. Utilization of conventional scintillators (A B , complex oxides etc.) for this purpose is at present problematic due to the difficulties in obtaining crystals of necessary size, high light output, good transparency to the intrinsic radiation, high thermal resistance. I1 VI","PeriodicalId":287813,"journal":{"name":"1993 IEEE Conference Record Nuclear Science Symposium and Medical Imaging Conference","volume":"148 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133912080","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1993-10-31DOI: 10.1109/NSSMIC.1993.701821
Min-Jen Tsai, B. Ho, J.D. Vidlasenor
A b e t Angiogram video sequence compression based on the wavelet repmeatation and fast motion estimation is presented in this paper. The characteristic motion of andograms is investigated, leading to a statistical result that is analyzed for fast motion estimation in order to get good inkrframe prediction. Wavelet transform decomposes the video frame into a set of subframes in different resolutions corresponding to different frequency scales. Weighted scale and uniform scalar quantization are applied to the subband co,.ffizients acccdng to their perceptual importance to the “stmcted k.age. Arithmetic coding is also used to achieve high codiqg efficiency for either base frame or error frame. The proposed dgol“lt!m not only achieves low bit-rate coding but also mainL?ir: hi&! fidslity which is essential for medical images.
{"title":"Motion Estimation And Wavelet Transform In Angiogram Video Coding","authors":"Min-Jen Tsai, B. Ho, J.D. Vidlasenor","doi":"10.1109/NSSMIC.1993.701821","DOIUrl":"https://doi.org/10.1109/NSSMIC.1993.701821","url":null,"abstract":"A b e t Angiogram video sequence compression based on the wavelet repmeatation and fast motion estimation is presented in this paper. The characteristic motion of andograms is investigated, leading to a statistical result that is analyzed for fast motion estimation in order to get good inkrframe prediction. Wavelet transform decomposes the video frame into a set of subframes in different resolutions corresponding to different frequency scales. Weighted scale and uniform scalar quantization are applied to the subband co,.ffizients acccdng to their perceptual importance to the “stmcted k.age. Arithmetic coding is also used to achieve high codiqg efficiency for either base frame or error frame. The proposed dgol“lt!m not only achieves low bit-rate coding but also mainL?ir: hi&! fidslity which is essential for medical images.","PeriodicalId":287813,"journal":{"name":"1993 IEEE Conference Record Nuclear Science Symposium and Medical Imaging Conference","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134181759","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1993-10-31DOI: 10.1109/NSSMIC.1993.701764
C. Fordham, I. Ali, B. Behrens, C. Foudas, A. Goussiou, M. Jaworski, S. Silverstein, W. Smith, U. Wisconsin, J. Dawson, D. Krakauer, R. Talaga
{"title":"High Speed Pipelined Pattern Recognition","authors":"C. Fordham, I. Ali, B. Behrens, C. Foudas, A. Goussiou, M. Jaworski, S. Silverstein, W. Smith, U. Wisconsin, J. Dawson, D. Krakauer, R. Talaga","doi":"10.1109/NSSMIC.1993.701764","DOIUrl":"https://doi.org/10.1109/NSSMIC.1993.701764","url":null,"abstract":"","PeriodicalId":287813,"journal":{"name":"1993 IEEE Conference Record Nuclear Science Symposium and Medical Imaging Conference","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133083248","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1993-10-31DOI: 10.1109/NSSMIC.1993.701775
R.H. Buchert, C. Beck
This paper is the result of a recent NRC concern with the impact of transient inrush current on motor operated valve (MOV) starting. It provides the background for this issue, discusses the accuracy of measured current traces, presents the theory behind transient inrush, analyzes a set of VOTES test data, and discusses its impact on motor starting to determine whether the concern had a valid, technical basis.
{"title":"Impact Of Transient Inrush On MOV Starting","authors":"R.H. Buchert, C. Beck","doi":"10.1109/NSSMIC.1993.701775","DOIUrl":"https://doi.org/10.1109/NSSMIC.1993.701775","url":null,"abstract":"This paper is the result of a recent NRC concern with the impact of transient inrush current on motor operated valve (MOV) starting. It provides the background for this issue, discusses the accuracy of measured current traces, presents the theory behind transient inrush, analyzes a set of VOTES test data, and discusses its impact on motor starting to determine whether the concern had a valid, technical basis.","PeriodicalId":287813,"journal":{"name":"1993 IEEE Conference Record Nuclear Science Symposium and Medical Imaging Conference","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132644844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1993-10-31DOI: 10.1109/NSSMIC.1993.373611
J. Rogers, R. Nutt, M. Andreaco, C. Williams
New block detectors have been fabricated incorporating large numbers of small crystals. The authors evaluate and compare the performance of the new detectors with a standard 64-crystal block detector from Siemens-CTI. The new detectors demonstrate greatly improved imaging capability for 511 keV gamma rays. Future PET tomographs incorporating such detectors should produce substantially better volume images with little increase in tomograph manufacturing costs. The detectors will require a new type of automatic calibration procedure. Various such procedures have been tested and are discussed. A technique using higher energy gamma rays has shown special promise.<>
{"title":"Testing 144- and 256-crystal BGO block detectors","authors":"J. Rogers, R. Nutt, M. Andreaco, C. Williams","doi":"10.1109/NSSMIC.1993.373611","DOIUrl":"https://doi.org/10.1109/NSSMIC.1993.373611","url":null,"abstract":"New block detectors have been fabricated incorporating large numbers of small crystals. The authors evaluate and compare the performance of the new detectors with a standard 64-crystal block detector from Siemens-CTI. The new detectors demonstrate greatly improved imaging capability for 511 keV gamma rays. Future PET tomographs incorporating such detectors should produce substantially better volume images with little increase in tomograph manufacturing costs. The detectors will require a new type of automatic calibration procedure. Various such procedures have been tested and are discussed. A technique using higher energy gamma rays has shown special promise.<<ETX>>","PeriodicalId":287813,"journal":{"name":"1993 IEEE Conference Record Nuclear Science Symposium and Medical Imaging Conference","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132713272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1993-10-31DOI: 10.1109/NSSMIC.1993.701661
M. Bosetti, C. Furetta, C. Leroy, S. Pensotti, A. Penzo, P. Rancoita, M. Rattaggi, M. Redaelli, G. Salvato, G. Terzi
The energy resolution of electromagnetic sampling calorimeters using silicon mosaics as active medium, has been measured for Pb and Fe absorbers at incoming electron energies E of 2, 4, and 6 GeV. The energy resolution, found for the Si/Pb sented by a(E)/E = pling frequency. The energy resolution can be rewritten as a function of the dead area energy losses (D): a(E)/E = (KO + all))% ,/- with KO = (17.6 f 0.3)%, (24.1&0.8)%, for Si/Pb, Si/Fe, respectively; a1 = 1.2f0.3 for both absorbers.
以硅镶嵌片为有效介质的电磁取样量热计，测量了Pb和Fe吸收剂在入射电子能E为2、4和6 GeV时的能量分辨率。通过a(E)/E =频率发送的Si/Pb的能量分辨率。能量分辨率可以改写为死区能量损失(D)的函数:对于Si/Pb, Si/Fe, a(E)/E = (KO + all))%，/- KO = (17.6 f 0.3)%， (24.1&0.8)%;两个吸收体A1 = 1.2f0.3。
{"title":"Energy Resolution Of Si/Fe And Si/Pb Electromagnetic Calorimeters","authors":"M. Bosetti, C. Furetta, C. Leroy, S. Pensotti, A. Penzo, P. Rancoita, M. Rattaggi, M. Redaelli, G. Salvato, G. Terzi","doi":"10.1109/NSSMIC.1993.701661","DOIUrl":"https://doi.org/10.1109/NSSMIC.1993.701661","url":null,"abstract":"The energy resolution of electromagnetic sampling calorimeters using silicon mosaics as active medium, has been measured for Pb and Fe absorbers at incoming electron energies E of 2, 4, and 6 GeV. The energy resolution, found for the Si/Pb sented by a(E)/E = pling frequency. The energy resolution can be rewritten as a function of the dead area energy losses (D): a(E)/E = (KO + all))% ,/- with KO = (17.6 f 0.3)%, (24.1&0.8)%, for Si/Pb, Si/Fe, respectively; a1 = 1.2f0.3 for both absorbers.","PeriodicalId":287813,"journal":{"name":"1993 IEEE Conference Record Nuclear Science Symposium and Medical Imaging Conference","volume":"307 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124246834","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：