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Showing 1 to 20 of 92 for “"Multigroup"”.
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Adaptive multigroup radiation diffusion
… increasing the accuracy and reliability of multigroup radiation diffusion simulations at low group counts. This is achieved by allowing the energy group boundaries to move in energy space as the simulation evolves. This adaption in energy space effectively removes the sensitivity of …
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Discrete generalized multigroup theory and applications
… a fundamentally new discrete generalized multigroup energy expansion theory for the linear Boltzmann transport equation. Discrete orthogonal polynomials are used, in conjunction with the traditional multigroup representation, to expand the energy dependence of the angular flux into a set …
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Green's Dyadic Solutions of the Multigroup Diffusion Equations
Made available in DSpace on 2017-07-06T18:55:32Z (GMT). No. of bitstreams: 3 Nanko_Laura_J_MS.pdf: 41554738 bytes, checksum: c55e8f034214ba6de4ec649d2ae00b66 (MD5) Nanko_Laura_J_MS_ABS.pdf: 658223 bytes, checksum: 8cab0e76fe0d4f99e812bca5b950d987 (MD5) license.txt: 4813 bytes, checksum: …
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Multigroup cross section generation via Monte Carlo methods
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1997.
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Resonance treatment using the Discrete Generalized Multigroup method
… are desired. Continuous energy or ultrafine multigroup nuclear data allows this high fidelity to be achieved but is associated with a high computational expense. This thesis proposes that the Discrete Generalized Multigroup (DGM) method is a possible means of approximating the high fidelity …
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A functional analytic approach to multigroup transport theory
… case in 1973 is applied to full and half-space multigroup problems in one dimension with a constant and invertible transfer matrix. The Case-type eigenfunction expansion formulas for the solutions of these problems are explicitly obtained. For the half-space case, the formulas are expressed in …
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Multigroup transport equations with nondiagonal cross section matrices
It is shown that multigroup transport equations with nondiagonal cross section matrices arise when the modal approximation is applied to energy dependent transport equations. This work is a study of such equations for the case that the cross section matrix is nondiagonalizable. For the special case …
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A transient nodal method accounting for multigroup transport effects
Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1994.
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On multigroup transport theory with a degenerate transfer kernel
The multigroup transport operator is studied in plane geometry assuming that the transfer kernel can be represented in a degenerate form. The eigenvalue spectrum is analyzed constructing the pertinent dispersion matrix in a block matrix form. The associated eigensolutions are obtained in terms of …
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A Coarse-Mesh Nodal Method for Multigroup Multidimensional Neutron Diffusion Computations
Made available in DSpace on 2017-07-06T18:55:44Z (GMT). No. of bitstreams: 3 Ougouag_Abderrafi_Mohammed-El-Amine_MS.pdf: 56136085 bytes, checksum: 179625ed39e2fdbc18ddbea719f128f8 (MD5) Ougouag_Abderrafi_Mohammed-El-Amine_MS_ABS.pdf: 634997 bytes, checksum: 89b895aa2f221ef9a70021aabe1778eb (MD5) …
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Multigroup, Spatially Dependent Studies of Mild Excursions in Large Fast Reactors
Made available in DSpace on 2014-12-11T17:26:05Z (GMT). No. of bitstreams: 1 7121211.pdf: 4419876 bytes, checksum: 0f7b829cc1bb034c93001e952ce2ebfa (MD5) Previous issue date: 1971
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The Phase Space Time Evolution method applied to multigroup neutron transport
… the one speed case to a more general multigroup code. Also the complications which arose in this transformation are discussed. The multigroup formulation of the PSTE method calculates the energy dependent scalar and angular neutron density at very small time increments. In a reactor …
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Advanced application of the discrete generalized multigroup method and recondensation to reactor analysis
… Recondensation using the Discrete Generalized Multigroup (DGM) method, though, offers a relatively cheap alternative to solving the fine group transport problem. DGM, however, suffered from inconsistencies when applied to high-order spatial methods. Many different approaches were taken to …
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The Green's dyadic method for the analytic solution of multigroup neutron transport boundary value problems
… is developed for the exact solution of the multigroup neutron transport equation. The method is based on the treatment of the steady-state, plane geometry multigroup equations for general anisotropic scattering in a homogenous medium. The problem of a system of N coupled integrodifferential …
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Moral Outrage Moderates the Relationships Between System Perception, System Justification, and Intergroup Helping Behavior: A Multigroup Approach
… under the same procedure and assessed a multigroup structural model of the relationships between the same variables. The main hypothesized model assessed if moral outrage moderated the relationships between perceptions of system legitimacy and system justification beliefs as well as the …
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A Multigroup One-Dimensional Tokamak Fusion Plasma Simulation for Non-Maxwellian Ions Slowing Down in a Thermal Background
Made available in DSpace on 2017-07-06T18:55:22Z (GMT). No. of bitstreams: 3 Metzger_John_D_MS.pdf: 41206592 bytes, checksum: a0be3867681c02996506c2473d60f688 (MD5) Metzger_John_D_MS_ABS.pdf: 545248 bytes, checksum: 9c976cf6a227887c97014849b6ac438a (MD5) license.txt: 4813 bytes, checksum: …
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A Numerical Solution of Low-Energy Neutron Boltzmann Equation
<p>A multigroup method using a straight ahead approximation is created to calculate low energy neutron fluence due to the elastic scattering of evaporation neutrons produced in interactions of high energy particles with target nuclei. This multigroup method is added to NASA Langley Research …
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Assessing Measurement Equivalence of the English and Spanish Versions on an Employee Attitude Survey Using Multigroup Analysis in Structural Equation Modeling.
… covariance structure comparison methodology - Multigroup Analysis in Structural Equation Modeling - evaluating measurement equivalence of English and Spanish versions of an employee opinion survey. The concept of measurement equivalence was defined as consisting of four components: sample …
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A Multigroup Analysis of the Psychological Factors that Contribute to Persisting Working Attention Problems in Mild Traumatic Brain Injury and Chronic Pain
<p>A significant subset of mild traumatic brain injury (mild TBI) and chronic pain (CP) patients report, and sometimes show objective evidence of, persisting cognitive problems. Despite differences in injury mechanisms, there is considerable overlap in the types of persisting cognitive symptoms …
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Mathematics Attitudes and Mathematics Performance: Novel Approaches towards Noncognitive Educational Measurement, Applications to Large-scale Assessment Data, and Examinations of Multigroup Invariance
<p>Academic performance is predicted by a multitude of demographic, contextual, cognitive, and noncognitive constructs. The noncognitive factors of achievement in mathematics that have previously been explored in depth are study skills, collaborative problem-solving, confidence, self-efficacy, and …
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