Parallel Branch-and-Bound Algorithms
نویسندگان
چکیده
1.1. INTRODUCTION In the beginning of the twenty-first century, large unsolved combinatorial optimization problems have been solved exactly. Two impressive cases should be mentioned. First are two instances of the Monde, Transfert) newspapers. This impressive media frenzy reflected the impact of the achievement, which was deemed of the same order of magnitude as the victory of IBMs parallel computer DeepBlue over the chess world champion Kasparov. Several factors combined to bring on these achievements. A first reason is the scientific progress in Operations Research, in particular regarding the quality of the lower bounds for these problems (cutting plane techniques for the TSP and convex quadratic programming for the QAP). The computation of these new bounds is very time consuming, however. Moreover, the bounds are computed at each node of a tree whose size is huge (several billions of nodes). The progress in processor computing power certainly contributed.
منابع مشابه
A Comparative Study of Exact Algorithms for the Two Dimensional Strip Packing Problem
In this paper we consider a two dimensional strip packing problem. The problem consists of packing a set of rectangular items in one strip of width W and infinite height. They must be packed without overlapping, parallel to the edge of the strip and we assume that the items are oriented, i.e. they cannot be rotated. To solve this problem, we use three exact methods: a branch and bound method, a...
متن کاملFast Priority Queues for Parallel Branch-and-Bound
Currently used parallel best rst branch-and-bound algorithms either suuer from contention at a centralized priority queue or can only approximate the best rst strategy. Bottleneck free algorithms for parallel priority queues are known but they cannot be implemented very eeciently on contemporary machines. We present quite simple randomized algorithms for parallel priority queues on distributed ...
متن کاملAn Interface Design for General Parallel Branch-and-Bound Algorithms
Branch-and-Bound algorithms are general methods applicable to various combinatorial optimization problems. There are two hopeful methods to improve the algorithms. One is development of the algorithms which exploit the structure of each problem. The other is parallelization of the algorithms. These two methods have been studied by di erent research communities independently. If a well-designed ...
متن کاملPerformance of Parallel Branch and Bound Algorithms on the KSR1 Multiprocessor
In this paper we consider the parallelization of the branch and bound (BB) algorithm with best-rst search strategy on the KSR1 shared-memory mul-tiprocessor. Two shared-memory parallel BB algorithms are implemented on a 56-processor system. Measurements indicate that the scalability of the two algorithms is limited by the cost of interprocessor communications and by the cost of synchronization....
متن کاملA generalized utility for parallel branch and bound algorithms
Branch and bound algorithms are general methods applied to various combinatorial optimization problems. Recently, parallelizations of these algorithms have been proposed. In spite of the generality of these methods, many of the parallelizations have been set up for a speciic problem and a speciic parallel computer. In this paper, a generalized utility PUBB (Parallel-ization Utility for Branch a...
متن کاملTowards a Taxonomy of Parallel Branch and Bound Algorithms
In this paper we present a classification of parallel branch and bound algorithms, and elaborate on the consequences of particular parameter settings. The taxonomy is based upon how the algorithms handle the knowledge about the problem instance to be solved, generated during execution. The starting point of the taxonomy is the generally accepted description of the sequential branch and bound al...
متن کامل