Finite element meshes and node-numberings suitable for parallel solution with equally loaded processors are presented for linear orthotropic elliptic partial differential equations. These problems are of great importance, for instance in the oil and airfoil industries. The linear systems of equation
Fast and Scalable Parallel Algorithms for Knapsack-like Problems
β Scribed by Afonso Ferreira; John Michael Robson
- Publisher
- Elsevier Science
- Year
- 1996
- Tongue
- English
- Weight
- 403 KB
- Volume
- 39
- Category
- Article
- ISSN
- 0743-7315
No coin nor oath required. For personal study only.
β¦ Synopsis
We present two new algorithms for searching in sorted X Ψ Y Ψ R Ψ S, one based on heaps and the other on sampling. Each of the algorithms runs in time O(n 2 log n) (n being the size of the sorted arrays X, Y, R, and S). Hence in each case, by constructing arrays of size n β«Ψβ¬ O(2 s/4 ), we obtain a new algorithm for solving certain NP-complete problems such as knapsack on s data items in time equal (up to a constant factor) to the best algorithm currently known. Each of the algorithms is capable of being efficiently implemented in parallel and so solving large instances of these NP-complete problems fast on coarse-grained distributed memory parallel computers. The parallel version of the heap based algorithm is communicationefficient and exhibits optimal speedup for a number of processors less than n using O(n) space in each one; the sampling based algorithm exhibits optimal speedup for any number of processors up to n using O(n) space in total provided that the architecture is capable of logarithmic time sorting.
π SIMILAR VOLUMES
## Abstract Along with the development of graphics processing Units (GPUS) in floating point operations and programmability, GPU has increasingly become an attractive alternative to the central processing unit (CPU) for some of computeβintensive and parallel tasks.In this article, the multilevel fa
This paper gives output-sensitive parallel algorithms whose performance depends on the output size and are significantly more efficient tan previous algorithms for problems with sufficiently small output size. Inputs are n\_n matrices over a fixed ground field. Let P(n) and M(n) be the PRAM processo
In fact, Vizing's proof implies an O(nm) time algorithm with β¬ Ο© 1 colors for the edge-coloring problem. However, Holyer has shown that deciding whether a graph requires β¬ or β¬ Ο© 1 colors is NP-complete [10]. For a multigraph G, Shannon showed that Π(G) Υ 3β¬/2 [16]. A number of parallel algorithms