Multiregion


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Electromagnetic Scattering using the Iterative Multi-Region Technique


Book Description

In this work, an iterative approach using the finite difference frequency domain method is presented to solve the problem of scattering from large-scale electromagnetic structures. The idea of the proposed iterative approach is to divide one computational domain into smaller subregions and solve each subregion separately. Then the subregion solutions are combined iteratively to obtain a solution for the complete domain. As a result, a considerable reduction in the computation time and memory is achieved. This procedure is referred to as the iterative multiregion (IMR) technique. Different enhancement procedures are investigated and introduced toward the construction of this technique. These procedures are the following: 1) a hybrid technique combining the IMR technique and a method of moment technique is found to be efficient in producing accurate results with a remarkable computer memory saving; 2) the IMR technique is implemented on a parallel platform that led to a tremendous computational time saving; 3) together, the multigrid technique and the incomplete lower and upper preconditioner are used with the IMR technique to speed up the convergence rate of the final solution, which reduces the total computational time. Thus, the proposed iterative technique, in conjunction with the enhancement procedures, introduces a novel approach to solving large open-boundary electromagnetic problems including unconnected objects in an efficient and robust way. Contents: Basics of the FDFD Method / IMR Technique for Large-Scale Electromagnetic Scattering Problems: 3D Case / IMR Technique for Large-Scale Electromagnetic Scattering Problems: 2D Case / The IMR Algorithm Using a Hybrid FDFD and Method of Moments Technique / Parallelization of the Iterative Multiregion Technique / Combined Multigrid Technique and IMR Algorithm / Concluding Remarks / Appendices







Medial/Skeletal Linking Structures for Multi-Region Configurations


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The authors consider a generic configuration of regions, consisting of a collection of distinct compact regions in which may be either regions with smooth boundaries disjoint from the others or regions which meet on their piecewise smooth boundaries in a generic way. They introduce a skeletal linking structure for the collection of regions which simultaneously captures the regions' individual shapes and geometric properties as well as the “positional geometry” of the collection. The linking structure extends in a minimal way the individual “skeletal structures” on each of the regions. This allows the authors to significantly extend the mathematical methods introduced for single regions to the configuration of regions.







Microscopic Lattice Parameters in Single-and Multi-region Cores


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Light water critical experiments have been performed in order to measure microscopic parameters and conversion ratios in single region and multi-region cores containing slightly enriched, stainless steel clad, UO2 fuel rods. The experimental results were analyzed with multi-group codes which were supplemented for the resonance energy by a Monte Carlo code. Experimental and analytical results are presented along with a description of experimental and analystical investigations performed in order to account for discrepancies between theory and experiment.







Multiregional Clinical Trials for Simultaneous Global New Drug Development


Book Description

In a global clinical development strategy, multiregional clinical trials (MRCTs) are vital in the development of innovative medicines. Multiregional Clinical Trials for Simultaneous Global New Drug Development presents a comprehensive overview on the current status of conducting MRCTs in clinical development. International experts from academia, in




Applied Multiregional Demography Through Problems


Book Description

Written by the 2018 Mindel C. Sheps Award winner, this textbook offers a unique method for teaching how to model spatial (multiregional) population dynamics through models of increasing complexity. Each chapter in this programmed workbook starts with a descriptive text, followed by a sequence of exercises focused on particular multiregional models, of increasing complexity, and then ends with the solutions. It extends the current developments in the spatial analysis of social data towards improving our understanding of dynamics and interacting change across multiple populations in space. Frameworks for analyzing such dynamics were first proposed in multiregional demography, over 40 years ago. This book revisits these methods and then illustrates how they may be used to analyze spatial data and study spatial population dynamics. Topics covered include spatial population dynamics, population projections and estimations, spatial and age structure of migration flows and much more. As such this innovative textbook is a great teaching and learning tool for teachers, students as well as individuals who want to study demographic processes across space.




NRIES


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