Aggregation in Large-Scale Optimization

Aggregation in Large-Scale Optimization

Author: I. Litvinchev

Publisher: Springer Science & Business Media

Published: 2013-12-01

Total Pages: 301

ISBN-13: 1441991549

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When analyzing systems with a large number of parameters, the dimen sion of the original system may present insurmountable difficulties for the analysis. It may then be convenient to reformulate the original system in terms of substantially fewer aggregated variables, or macrovariables. In other words, an original system with an n-dimensional vector of states is reformulated as a system with a vector of dimension much less than n. The aggregated variables are either readily defined and processed, or the aggregated system may be considered as an approximate model for the orig inal system. In the latter case, the operation of the original system can be exhaustively analyzed within the framework of the aggregated model, and one faces the problems of defining the rules for introducing macrovariables, specifying loss of information and accuracy, recovering original variables from aggregates, etc. We consider also in detail the so-called iterative aggregation approach. It constructs an iterative process, at· every step of which a macroproblem is solved that is simpler than the original problem because of its lower dimension. Aggregation weights are then updated, and the procedure passes to the next step. Macrovariables are commonly used in coordinating problems of hierarchical optimization.


Large-scale Optimization

Large-scale Optimization

Author: Vladimir Tsurkov

Publisher: Springer Science & Business Media

Published: 2013-03-09

Total Pages: 322

ISBN-13: 1475732430

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Decomposition methods aim to reduce large-scale problems to simpler problems. This monograph presents selected aspects of the dimension-reduction problem. Exact and approximate aggregations of multidimensional systems are developed and from a known model of input-output balance, aggregation methods are categorized. The issues of loss of accuracy, recovery of original variables (disaggregation), and compatibility conditions are analyzed in detail. The method of iterative aggregation in large-scale problems is studied. For fixed weights, successively simpler aggregated problems are solved and the convergence of their solution to that of the original problem is analyzed. An introduction to block integer programming is considered. Duality theory, which is widely used in continuous block programming, does not work for the integer problem. A survey of alternative methods is presented and special attention is given to combined methods of decomposition. Block problems in which the coupling variables do not enter the binding constraints are studied. These models are worthwhile because they permit a decomposition with respect to primal and dual variables by two-level algorithms instead of three-level algorithms. Audience: This book is addressed to specialists in operations research, optimization, and optimal control.


Environmental Software Systems. Infrastructures, Services and Applications

Environmental Software Systems. Infrastructures, Services and Applications

Author: Ralf Denzer

Publisher: Springer

Published: 2015-02-09

Total Pages: 629

ISBN-13: 3319159941

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This book constitutes the refereed proceedings of the 11th IFIP WG 5.11 International Symposium on Environmental Software Systems, ISESS 2015, held in Melbourne, Australia, in March 2015. The 62 revised full papers presented were carefully reviewed and selected from 104 submissions. The papers are organized in the following topical sections: information systems, information modeling and semantics; decision support tools and systems; modelling and simulation systems; architectures, infrastructures, platforms and services; requirements, software engineering and software tools; analytics and visualization; and high-performance computing and big data.


Column Generation

Column Generation

Author: Guy Desaulniers

Publisher: Springer Science & Business Media

Published: 2006-03-20

Total Pages: 369

ISBN-13: 0387254862

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Column Generation is an insightful overview of the state of the art in integer programming column generation and its many applications. The volume begins with "A Primer in Column Generation" which outlines the theory and ideas necessary to solve large-scale practical problems, illustrated with a variety of examples. Other chapters follow this introduction on "Shortest Path Problems with Resource Constraints," "Vehicle Routing Problem with Time Window," "Branch-and-Price Heuristics," "Cutting Stock Problems," each dealing with methodological aspects of the field. Three chapters deal with transportation applications: "Large-scale Models in the Airline Industry," "Robust Inventory Ship Routing by Column Generation," and "Ship Scheduling with Recurring Visits and Visit Separation Requirements." Production is the focus of another three chapters: "Combining Column Generation and Lagrangian Relaxation," "Dantzig-Wolfe Decomposition for Job Shop Scheduling," and "Applying Column Generation to Machine Scheduling." The final chapter by François Vanderbeck, "Implementing Mixed Integer Column Generation," reviews how to set-up the Dantzig-Wolfe reformulation, adapt standard MIP techniques to the column generation context (branching, preprocessing, primal heuristics), and deal with specific column generation issues (initialization, stabilization, column management strategies).


Solving Network Design Problems via Decomposition, Aggregation and Approximation

Solving Network Design Problems via Decomposition, Aggregation and Approximation

Author: Andreas Bärmann

Publisher: Springer

Published: 2016-06-02

Total Pages: 206

ISBN-13: 3658139137

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Andreas Bärmann develops novel approaches for the solution of network design problems as they arise in various contexts of applied optimization. At the example of an optimal expansion of the German railway network until 2030, the author derives a tailor-made decomposition technique for multi-period network design problems. Next, he develops a general framework for the solution of network design problems via aggregation of the underlying graph structure. This approach is shown to save much computation time as compared to standard techniques. Finally, the author devises a modelling framework for the approximation of the robust counterpart under ellipsoidal uncertainty, an often-studied case in the literature. Each of these three approaches opens up a fascinating branch of research which promises a better theoretical understanding of the problem and an increasing range of solvable application settings at the same time.


Computer Aided Design of Control Systems

Computer Aided Design of Control Systems

Author: M. A. Cuenod

Publisher: Elsevier

Published: 2014-05-19

Total Pages: 703

ISBN-13: 148314691X

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Computer Aided Design of Control Systems focuses on the use of computers to analyze and design the control of various processes, as well as the development of program packages with different algorithms for digital computers. The selection first takes a look at the computer aided design of minimal order controllers, including design of interacting and noninteracting dynamic controllers of minimal order and basic algorithm. The book then discusses an accelerated Newton process to solve Riccati equation through matrix sign function; suboptimal direct digital control of a trickle-bed absorption column; and structural design of large systems employing a geometric approach. The text underscores the computer as an aid for the implementation of advanced control algorithms on physical processes and analysis of direct control algorithms and their parallel realization. Topics include hardware influences on the control, process influence, and interactive structure design of direct control systems. The book also takes a look at the optimal control of randomly sampled linear stochastic systems; computer aided design of suboptimal test signals for system identification; and computer aided design of multi-level systems with prescribed structure and control constraints. The selection is a dependable source of data for readers interested in the uses of computers.


Business Optimization Using Mathematical Programming

Business Optimization Using Mathematical Programming

Author: Josef Kallrath

Publisher: Springer Nature

Published: 2021-08-31

Total Pages: 653

ISBN-13: 3030732371

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This book presents a structured approach to formulate, model, and solve mathematical optimization problems for a wide range of real world situations. Among the problems covered are production, distribution and supply chain planning, scheduling, vehicle routing, as well as cutting stock, packing, and nesting. The optimization techniques used to solve the problems are primarily linear, mixed-integer linear, nonlinear, and mixed integer nonlinear programming. The book also covers important considerations for solving real-world optimization problems, such as dealing with valid inequalities and symmetry during the modeling phase, but also data interfacing and visualization of results in a more and more digitized world. The broad range of ideas and approaches presented helps the reader to learn how to model a variety of problems from process industry, paper and metals industry, the energy sector, and logistics using mathematical optimization techniques.


Software for Computer Control

Software for Computer Control

Author: M. Novak

Publisher: Elsevier

Published: 2014-05-19

Total Pages: 437

ISBN-13: 1483146383

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Software for Computer Control is a collection of papers and lectures presented at the Second IFAC/IFIP Symposium on Software for Computer Control, held in Prague, Czechoslovakia in June 1979. The symposium is organized with the hope of making vital contributions to the development of the computer sciences. The text focuses on the design and programming of process control systems used in various industrial processes and experiments. Topics covered include communication control in computer networks; program generators for process control applications; methods for the design of control software; presentations on software for microprocessors; real-time languages; algorithms for computer control; and applications of computer control in sciences. Computer scientists, systems analysts, programmers, and students of computer science will benefit from this book.


Advances of Artificial Intelligence in a Green Energy Environment

Advances of Artificial Intelligence in a Green Energy Environment

Author: Pandian Vasant

Publisher: Academic Press

Published: 2022-05-20

Total Pages: 416

ISBN-13: 0323885748

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Advances of Artificial Intelligence in a Green Energy Environment reviews the new technologies in intelligent computing and AI that are reducing the dimension of data coverage worldwide. This handbook describes intelligent optimization algorithms that can be applied in various branches of energy engineering where uncertainty is a major concern. Including AI methodologies and applying advanced evolutionary algorithms to real-world application problems for everyday life applications, this book considers distributed energy systems, hybrid renewable energy systems using AI methods, and new opportunities in blockchain technology in smart energy. Covering state-of-the-art developments in a fast-moving technology, this reference is useful for engineering students and researchers interested and working in the AI industry. - Looks at new techniques in artificial intelligence (AI) reducing the dimension of data coverage worldwide - Chapters include AI methodologies using enhanced hybrid swarm-based optimization algorithms - Includes flowchart diagrams for exampling optimizing techniques