We present several new steepest-edge simplex algorithms for solving linearprogramming problems, including variants of both the primal and the dual simplex method. These algorithms differ depending upon the space in w...
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We present several new steepest-edge simplex algorithms for solving linearprogramming problems, including variants of both the primal and the dual simplex method. These algorithms differ depending upon the space in which the problem is viewed as residing, and include variants in which this space varies dynamically. We present computational results comparing steepest-edge simplex algorithms and approximate versions of them against simplex algorithms that use standard pivoting rules on truly large-scale real-world linear programs with as many as tens of thousands of rows and columns. These results demonstrate unambiguously the superiority of steepest-edge pivot selection criteria to other pivot selection criteria in the simplex method.
The paper is devoted to a scalability study of the NSLP algorithm for solving non-stationary high-dimension linearprogramming problem on the cluster computing systems. The analysis is based on the BSF model of parall...
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ISBN:
(纸本)9783319712543;9783319712550
The paper is devoted to a scalability study of the NSLP algorithm for solving non-stationary high-dimension linearprogramming problem on the cluster computing systems. The analysis is based on the BSF model of parallel computations. The BSF model is a new parallel computation model designed on the basis of BSP and SPMD models. The brief descriptions of the NSLP algorithm and the BSF model are given. The NSLP algorithm implementation in the form of a BSF program is considered. On the basis of the BSF cost metric, the upper bound of the NSLP algorithm scalability is derived and its parallel efficiency is estimated. NSLP algorithm implementation using BSF skeleton is described. A comparison of scalability estimations obtained analytically and experimentally is provided.
The Big Data phenomenon has spawned large-scale linear programming problems. In many cases, these problems are nonstationary. In this paper, we describe a new scalable algorithm called NSLP for solving high-dimensiona...
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ISBN:
(纸本)9783319670355;9783319670348
The Big Data phenomenon has spawned large-scale linear programming problems. In many cases, these problems are nonstationary. In this paper, we describe a new scalable algorithm called NSLP for solving high-dimensional, non-stationary linearprogramming problems on modern cluster computing systems. The algorithm consists of two phases: Quest and Targeting. The Quest phase calculates a solution of the system of inequalities defining the constraint system of the linearprogramming problem under the condition of dynamic changes in input data. To this end, the apparatus of Fejer mappings is used. The Targeting phase forms a special system of points having the shape of an n-dimensional axisymmetric cross. The cross moves in the n-dimensional space in such a way that the solution of the linearprogramming problem is located all the time in an e-vicinity of the central point of the cross.
The paper describes a new scalable algorithm called NSLP for high-dimension, non-stationary linearprogramming problem solving on the modern cluster computing systems. The algorithm consists of two phases: Quest and T...
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ISBN:
(纸本)9781538605219
The paper describes a new scalable algorithm called NSLP for high-dimension, non-stationary linearprogramming problem solving on the modern cluster computing systems. The algorithm consists of two phases: Quest and Targeting. The Quest phase calculates a solution for the system of inequalities defining the constraint system of the linearprogramming problem under the condition of the input data dynamic changes. To do this, it uses the apparatus of Fejer maps. The Targeting phase forms a special system of points having the shape of the n-dimensional axisymmetric cross. The cross moves in the n-dimensional space in such a way that the solution of the linearprogramming problem is permanently in the epsilon-vicinity of the cross central point.
We study a class of linearprogramming (LP) problems motivated by large-scale machine learning applications. After reformulating the LP as a convex nonsmooth problem, we apply Nesterov's primal-dual excessive-gap ...
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We study a class of linearprogramming (LP) problems motivated by large-scale machine learning applications. After reformulating the LP as a convex nonsmooth problem, we apply Nesterov's primal-dual excessive-gap technique. The iteration complexity of the excessive-gap technique depends on a parameter theta that arises because we must bound the primal feasible set, which is originally unbounded. We also dynamically update theta to speed up the convergence. The application of our algorithm to two machine learning problems demonstrates several advantages of the excessive-gap technique over existing methods.
Which equipment should be bought for a given sum to increase the profit of an industrial enterprize with a known specification of production within given limits? This problem is described as a large-scalelinear progr...
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Which equipment should be bought for a given sum to increase the profit of an industrial enterprize with a known specification of production within given limits? This problem is described as a large-scalelinear program (LP) of a specific structure. An effective preliminary analysis for this structure was proposed in Ioslovich and Makarenkov [On methods of dimensionality reduction in linearprogramming, Econ. Math. Methods Moscow (in Russian) 11(3) (1975) 316-324] which aimed to reduce the size of the problem by detection of the redundant and active constraints. In this paper a robust system is considered, dealing with box-constrained uncertainties in the input coefficients. The analysis is based on robust evaluations of bounds for primal and dual constraints. A robust evaluation of uncertain duals presented in [I. Ioslovich, P.-O. Gutman, Robust redundancy determination and evaluation of the dual variables of linearprogramming problems in the presence of uncertainty, 1, in, V. Kucera, M. Sebek (Eds.), Proceedings of 3rd IFAC Symposium on Robust Control Design (ROCOND 2000), IFAC, Prague, Czech Republic, Elsevier Science, Amsterdam, 2000, paper 115] is essentially used. (C) 2007 The Franklin Institute. Published by Elsevier Ltd. All rights reserved.
This paper deals with an algorithm incorporating the interior-point method into the Dantzig-Wolfe decomposition technique for solving large-scale linear programming problems, The algorithm decomposes a linear program ...
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This paper deals with an algorithm incorporating the interior-point method into the Dantzig-Wolfe decomposition technique for solving large-scale linear programming problems, The algorithm decomposes a linear program into a main problem and a subproblem. The subproblem is solved approximately. Hence, inexact Newton directions are used in solving the main problem. We show that the algorithm is globally linearly convergent and has polynomial-time complexity.
We propose a new pivot rule for the simplex algorithm, which is demonstrative in the dual space intuitively. Although it is based on normalized reduced costs, like the steepest-edge rule and its variants, the rule is ...
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We propose a new pivot rule for the simplex algorithm, which is demonstrative in the dual space intuitively. Although it is based on normalized reduced costs, like the steepest-edge rule and its variants, the rule is much simpler and cheaper than the latter. We report computational results obtained with the 47 largest Netlib problems in terms of the number of rows and columns, all of the 16 Kennington problems, and the 17 largest BPMPD problems. Over the total 80 problems, a variant of the rule outperformed the Devex rule with iterations and time ratio 1.43 and 3.24, respectively. (c) 2007 Elsevier B.V. All rights reserved.
The integrated refinery-planning (IRP), an instrumental problem in the petroleum industry, is made of several subsystems, each of them involving a large number of decisions. Despite the complexity of the overall plann...
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The integrated refinery-planning (IRP), an instrumental problem in the petroleum industry, is made of several subsystems, each of them involving a large number of decisions. Despite the complexity of the overall planning problem, this work presents a mathematical model of the refinery operations characterized by complete horizontal integration of subsystems from crude oil purchase through to product distribution. This is the main contribution from a modelling point of view. The IRP, with a planning horizon ranging from 2 to 300 days. results in a large-scale linear programming (LP) problem of up to one million constraints, 2.5 million variables and 59 millions of nonzeroes in the constraint matrix. large instances become computationally challenging for generic state-of-the-art LP solvers, such as CPLEX. To avoid this drawback, after the identification of the nonzero structure of the constraints matrix, structure-exploiting techniques such as Dantzig-Wolfe and block coordinate-descent decomposition were applied to IRP. It was also observed that interior-point methods are far more efficient than simplex ones in large IRP instances. These were the main contributions from the optimization viewpoint. A set of realistic instances were dealt with generic algorithms and these two decomposition methods. In particular the block coordinate-descent heuristic, with a reverse order of the subsystems, appeared as a promising approach for very large integrated refinery problems, obtaining either the optimal or an approximate feasible solution in all the instances tested. (c) 2008 Elsevier Ltd. All rights reserved.
In this paper, by considering the experts' imprecise or fuzzy understanding of the nature of the parameters in the problem-formulation process, large-scale multiobjective block-angular linearprogramming problems ...
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In this paper, by considering the experts' imprecise or fuzzy understanding of the nature of the parameters in the problem-formulation process, large-scale multiobjective block-angular linearprogramming problems involving fuzzy numbers are formulated. Through the use of the alpha-level sets of fuzzy numbers, an extended Pareto optimality concept, called the alpha-Pareto optimality is introduced. To generate a candidate for the satisficing solution which is also alpha-Pareto optimal, decision maker is asked to specify the degree alpha and the reference objective values. It is shown that the corresponding alpha-Pareto optimal solution can be easily obtained by solving the minimax problems for which the Dantzig-Wolfe decomposition method is applicable. Then a linearprogramming-based interactive decision-making method for deriving a satisficing solution for the decision maker efficiently from an alpha-Pareto optimal solution set is presented. (C) 1997 Elsevier Science B.V.
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