The Experts below are selected from a list of 249 Experts worldwide ranked by ideXlab platform
F. Kahl - One of the best experts on this subject based on the ideXlab platform.
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A Critical Configuration for reconstruction from rectilinear motion
2003 IEEE Computer Society Conference on Computer Vision and Pattern Recognition 2003. Proceedings., 2003Co-Authors: R. Hartley, F. KahlAbstract:This paper investigates Critical Configurations for projective reconstruction from multiple images taken by a camera moving in a straight line. Projective reconstruction refers to a determination of the 3D (three-dimensional) geometrical Configuration of a set of 3D points and cameras, given only correspondences between points in the images. A Configuration of points and cameras is Critical if it cannot be determined uniquely (up to a projective transform) from the image coordinates of the points. It is shown that a Configuration consisting of any number of cameras lying on a straight line, and any number of points lying on a twisted cubic constitutes a Critical Configuration. An alternative Configuration consisting of a set of points and cameras all lying on a rational quartic curve exists.
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CVPR (1) - A Critical Configuration for reconstruction from rectilinear motion
2003 IEEE Computer Society Conference on Computer Vision and Pattern Recognition 2003. Proceedings., 2003Co-Authors: R. Hartley, F. KahlAbstract:This paper investigates Critical Configurations for projective reconstruction from multiple images taken by a camera moving in a straight line. Projective reconstruction refers to a determination of the 3D (three-dimensional) geometrical Configuration of a set of 3D points and cameras, given only correspondences between points in the images. A Configuration of points and cameras is Critical if it cannot be determined uniquely (up to a projective transform) from the image coordinates of the points. It is shown that a Configuration consisting of any number of cameras lying on a straight line, and any number of points lying on a twisted cubic constitutes a Critical Configuration. An alternative Configuration consisting of a set of points and cameras all lying on a rational quartic curve exists.
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CVPR (2) - Critical Configurations for n-view projective reconstruction
Proceedings of the 2001 IEEE Computer Society Conference on Computer Vision and Pattern Recognition. CVPR 2001, 2001Co-Authors: F. Kahl, R. Hartley, K. AstromAbstract:In this paper we give a characterization of Critical Configurations for projective reconstruction with any number of points and views. A set of cameras and points is said to be Critical if the projected image points are insufficient to determine the placement of the points and the cameras uniquely, up to a projective transformation. For two views, the Critical Configurations are well-known. In this paper it is shown that a Configuration of n 3 cameras and in points all lying on the intersection of two distinct ruled quadrics is Critical. In distinction to the two-view case, which in general allows two alternative solutions, there is a family of ambiguous reconstructions for the n-view case. As a partial converse, it Is shown that for any Critical Configuration, all the points lie on the intersection of two ruled quadrics.
S M Bowman - One of the best experts on this subject based on the ideXlab platform.
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scale 4 analysis of pressurized water reactor Critical Configurations volume 5 north anna unit 1 cycle 5
Other Information: PBD: 1 Jan 1993, 1993Co-Authors: S M Bowman, T SutoAbstract:ANSI/ANS 8.1 requires that calculational methods for away-from- reactor (AFR) Criticality safety analyses be validated against experiment. This report summarizes part of the ongoing effort to benchmark AFR Criticality analysis methods using selected Critical Configurations from commercial PWRs. Codes and data in the SCALE-4 code system were used. This volume documents the SCALE system analysis of one reactor Critical Configuration for North Anna Unit 1 Cycle 5. The KENO V.a Criticality calculations for the North Anna 1 Cycle 5 beginning-of-cycle model yielded a value for k{sub eff} of 1. 0040{+-}0.0005.
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Scale-4 Analysis of Pressurized Water Reactor Critical Configurations: Volume 5 - North Anna Unit 1 Cycle 5
1993Co-Authors: S M BowmanAbstract:The requirements of ANSI/ANS 8.1 specify that calculational methods for away-from-reactor (AFR) Criticality safety analyses be validated against experimental measurements. If credit for the negative reactivity of the depleted (or spent) fuel isotopics is desired, it is necessary to benchmark computational methods against spent fuel Critical Configurations. This report summarizes a portion of the ongoing effort to benchmark AFR Criticality analysis methods using selected Critical Configurations from commercial pressurized-water reactors (PWR). The analysis methodology selected for all calculations reported herein was the codes and data provided in the SCALE-4 code system. The isotopic densities for the spent fuel assemblies in the Critical Configurations were calculated using the SAS2H analytical sequence of the SCALE-4 system. The sources of data and the procedures for deriving SAS2H input parameters are described in detail. The SNIKR code module was used to extract the necessary isotopic densities from the SAS2H results and to provide the data in the format required by the SCALE Criticality analysis modules. The CSASN analytical sequence in SCALE-4 was used to perform resonance processing of the cross sections. The KENO V.a module of SCALE-4 was used to calculate the effective multiplication factor (k{sub eff}) of each case. The SCALE-4 27-group burnup library containing ENDF/B-IV (actinides) and ENDF/B-V (fission products) data was used for all the calculations. This volume of the report documents the SCALE system analysis of one reactor Critical Configuration for North Anna Unit 1 Cycle 5. This unit and cycle were chosen for a previous analysis using a different methodology because detailed isotopics from multidimensional reactor calculations were available from the Virginia Power Company. These data permitted comparison of Criticality calculations directly using the utility-calculated isotopics to those using the isotopics generated by the SCALE-4 SAS2H sequence. This reactor Critical benchmark has been reanalyzed using the methodology described above. The benchmark Critical calculation was the beginning-of-cycle (BOC) startup at hot, zero power (HZP). The k{sub eff} result was 1.0040, with a standard deviation of 0.0005
M D Dehart - One of the best experts on this subject based on the ideXlab platform.
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scale 4 analysis of pressurized water reactor Critical Configurations volume 1 summary
Other Information: PBD: 1 Jan 1995, 1995Co-Authors: M D DehartAbstract:The requirements of ANSI/ANS 8.1 specify that calculational methods for away-from-reactor Criticality safety analyses be validated against experimental measurements. If credit is to be taken for the reduced reactivity of burned or spent fuel relative to its original ''fresh'' composition, it is necessary to benchmark computational methods used in determining such reactivity worth against spent fuel reactivity measurements. This report summarizes a portion of the ongoing effort to benchmark away-from-reactor Criticality analysis methods using Critical Configurations from commercial pressurized- water reactors (PWR). The analysis methodology utilized for all calculations in this report is based on the modules and data associated with the SCALE-4 code system. Isotopic densities for spent fuel assemblies in the core were calculated using the SAS2H analytical sequence in SCALE-4. The sources of data and the procedures for deriving SAS2H input parameters are described in detail. The SNIKR code sequence was used to extract the necessary isotopic densities from SAS2H results and to provide the data in the format required for SCALE-4 Criticality analysis modules. The CSASN analytical sequence in SCALE-4 was used to perform resonance processing of cross sections. The KENO V.a module of SCALE-4 was used to calculate the effective multiplication factor (k{sub eff}) formore » the Critical Configuration. The SCALE-4 27-group burnup library containing ENDF/B-IV (actinides) and ENDF/B-V (fission products) data was used for analysis of each Critical Configuration. Each of the five volumes comprising this report provides an overview of the methodology applied. Subsequent volumes also describe in detail the approach taken in performing Criticality calculations for these PWR Configurations: Volume 2 describes Criticality calculations for the Tennessee Valley Authority's Sequoyah Unit 2 reactor for Cycle 3; Volume 3 documents the analysis of Virginia Power's Surry Unit 1 reactor for the Cycle 2 core; Volume 4 documents the calculations performed based on GPU Nuclear Corporation's Three Mile Island Unit 1 Cycle 5 core; and, lastly, Volume 5 describes the analysis of Virginia Power's North Anna Unit 1 Cycle 5 core. Each of the reactor-specific volumes provides the details of calculations performed to determine the effective multiplication factor for each reactor core for one or more Critical Configurations using the SCALE-4 system; these results are summarized in this volume. Differences between the core designs and their possible impact on the Criticality calculations are also discussed. Finally, results are presented for additional analyses performed to verify that solutions were sufficiently converged. All calculations show the ability to predict a k{sub eff} value very close to 1.0 for various conditions and cooling times. Thus, the methodology applied is shown to be a valid approach for calculating the value of k{sub eff} for systems with spent PWR fuel.« less
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Scale-4 Analysis of Pressurized Water Reactor Critical Configurations: Volume 4-Three Mile Island Unit 1 Cycle 5
1995Co-Authors: M D DehartAbstract:The requirements of ANSI/ANS-8.1 specify that calculational methods for away-from-reactor Criticality safety analyses be validated against experimental measurements. If credit is to be taken for the reduced reactivity of burned or spent fuel relative to its original ''fresh'' composition, it is necessary to benchmark computational methods used in determining such reactivity worth against spent fuel reactivity measurements. This report summarizes a portion of the ongoing effort to benchmark away-from-reactor Criticality analysis methods using relevant and well-documented Critical Configurations from commercial pressurized water reactors. The analysis methodology utilized for all calculations in this report is based on the modules and data associated with the SCALE-4 code system. Isotopic densities for spent fuel assemblies in the core were calculated using the SCALE-4 SAS2H analytical sequence. The sources of data and the procedures for deriving SAS2H input parameters are described in detail. The SNIKR code family was used to extract the necessary isotopic densities from SAS2H results and to provide the data in the format required for SCALE Criticality analysis modules. The CSASN analytical sequence in SCALE-4 was used to perform resonance processing of cross sections. The KENO V.a module of SCALE-4 was used to calculate the effective multiplication factor (k{sub eff}) for more » the Critical Configuration. The SCALE-4 27-group burnup library containing ENDF/B-IV (actinides) and ENDF/B-V (fission products) data was used for all calculations. This volume of the report documents a reactor Critical calculation for GPU Nuclear Corporation's Three Mile Island Unit 1 (TMI-1) during hot, zero-power startup testing for the beginning of cycle 5. This unit and cycle were selected because of their relevance in spent fuel benchmark applications: (1) cycle 5 startup occurred after an especially long downtime of 6.6 years; and (2) the core consisted primarily (75%) of burned fuel, with all fresh fuel loaded on the core outer periphery. A k{sub eff} value of 0.9978 {+-} 0.0004 was obtained using two million neutron histories in the KENO V.a model. This result is close to the known Critical k{sub eff} of 1.0 for the actual core and is consistent with other mixed-oxide Criticality benchmarks. Thus this method is shown to be valid for spent fuel applications in burnup credit analyses. « less
R. Hartley - One of the best experts on this subject based on the ideXlab platform.
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A Critical Configuration for reconstruction from rectilinear motion
2003 IEEE Computer Society Conference on Computer Vision and Pattern Recognition 2003. Proceedings., 2003Co-Authors: R. Hartley, F. KahlAbstract:This paper investigates Critical Configurations for projective reconstruction from multiple images taken by a camera moving in a straight line. Projective reconstruction refers to a determination of the 3D (three-dimensional) geometrical Configuration of a set of 3D points and cameras, given only correspondences between points in the images. A Configuration of points and cameras is Critical if it cannot be determined uniquely (up to a projective transform) from the image coordinates of the points. It is shown that a Configuration consisting of any number of cameras lying on a straight line, and any number of points lying on a twisted cubic constitutes a Critical Configuration. An alternative Configuration consisting of a set of points and cameras all lying on a rational quartic curve exists.
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CVPR (1) - A Critical Configuration for reconstruction from rectilinear motion
2003 IEEE Computer Society Conference on Computer Vision and Pattern Recognition 2003. Proceedings., 2003Co-Authors: R. Hartley, F. KahlAbstract:This paper investigates Critical Configurations for projective reconstruction from multiple images taken by a camera moving in a straight line. Projective reconstruction refers to a determination of the 3D (three-dimensional) geometrical Configuration of a set of 3D points and cameras, given only correspondences between points in the images. A Configuration of points and cameras is Critical if it cannot be determined uniquely (up to a projective transform) from the image coordinates of the points. It is shown that a Configuration consisting of any number of cameras lying on a straight line, and any number of points lying on a twisted cubic constitutes a Critical Configuration. An alternative Configuration consisting of a set of points and cameras all lying on a rational quartic curve exists.
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CVPR (2) - Critical Configurations for n-view projective reconstruction
Proceedings of the 2001 IEEE Computer Society Conference on Computer Vision and Pattern Recognition. CVPR 2001, 2001Co-Authors: F. Kahl, R. Hartley, K. AstromAbstract:In this paper we give a characterization of Critical Configurations for projective reconstruction with any number of points and views. A set of cameras and points is said to be Critical if the projected image points are insufficient to determine the placement of the points and the cameras uniquely, up to a projective transformation. For two views, the Critical Configurations are well-known. In this paper it is shown that a Configuration of n 3 cameras and in points all lying on the intersection of two distinct ruled quadrics is Critical. In distinction to the two-view case, which in general allows two alternative solutions, there is a family of ambiguous reconstructions for the n-view case. As a partial converse, it Is shown that for any Critical Configuration, all the points lie on the intersection of two ruled quadrics.
T Suto - One of the best experts on this subject based on the ideXlab platform.
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scale 4 analysis of pressurized water reactor Critical Configurations volume 5 north anna unit 1 cycle 5
Other Information: PBD: 1 Jan 1993, 1993Co-Authors: S M Bowman, T SutoAbstract:ANSI/ANS 8.1 requires that calculational methods for away-from- reactor (AFR) Criticality safety analyses be validated against experiment. This report summarizes part of the ongoing effort to benchmark AFR Criticality analysis methods using selected Critical Configurations from commercial PWRs. Codes and data in the SCALE-4 code system were used. This volume documents the SCALE system analysis of one reactor Critical Configuration for North Anna Unit 1 Cycle 5. The KENO V.a Criticality calculations for the North Anna 1 Cycle 5 beginning-of-cycle model yielded a value for k{sub eff} of 1. 0040{+-}0.0005.
