摘要摘要由於批量之決定影響生產系統之效率甚大，故在MRP架構中一直扮演著很重要的角色。雖然目前已有不少這方面之研究，大部份的最佳批量演算法卻受限於龐大之計算量而較不受實務界重視。隨著平行處理機的性能價格比日漸提昇，如何運用平行演算法以求解如動態批量這樣計算繁雜的問題便是一値得重視的研究方向。本文提出了二個動態批量平行演算法，在問題大小爲n時，前者複雜度爲O(n{su2})（如果有n個處理器），後者則爲O(n{su3}/p+np{su2})（如果有P個處理器，且P<algorithms is hindered by the huge amount of computer resources required to solve the models, even for a modest problem. Since the powerful parallel computers are becoming cost-effective nowadays, it is necessary to explore paraIlel algorithms that can be used to solve these laborious computational problems. This paper presents two parallel algorithms for solving dynamic lot sizing problem using the cost path concept. Given n is the size of the problem. it is shown that the first proposed parallel algorithm is O(n2) with n processors and the second proposed parallel algorithm iswith p processors (p<parallel algorithms and some future research directions are also provided.
This letter presents the modelling of a morphological thinning algorithm suggested by Jang and Chin [1] on the four models of shared memory SIMD computers. The time and cost complexity analyses for the models have bee...
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This letter presents the modelling of a morphological thinning algorithm suggested by Jang and Chin [1] on the four models of shared memory SIMD computers. The time and cost complexity analyses for the models have been given. The performance of this algorithm on SIMD computers has been compared with the performance of a conventional thinning algorithm [2] proposed recently.
The usual QR algorithm for finding the eigenvalues of a Hessenberg matrix H is based on vector-vector operations, e.g. adding a multiple of one row to another. The opportunities for parallelism in such an algorithm ar...
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The usual QR algorithm for finding the eigenvalues of a Hessenberg matrix H is based on vector-vector operations, e.g. adding a multiple of one row to another. The opportunities for parallelism in such an algorithm are limited. In this paper, we describe a reorganization of the QR algorithm to permit either matrix-vector or matrix-matrix operations to be performed, both of which yield more efficient implementations on vector and parallel machines. The idea is to chase a k by k bulge rather than a 1 by 1 or 2 by 2 bulge as in the standard QR algorithm. We report our preliminary numerical experiments on the CONVEX C-1 and CYBER 205 vector machines.
We present efficient algorithms for the nearest neighbor problem defined in an n × n binary image. We show that using a linear array with a reconfigurable pipelined bus system (LARPBS) of n2processors, the ne...
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We present efficient algorithms for the nearest neighbor problem defined in an n × n binary image. We show that using a linear array with a reconfigurable pipelined bus system (LARPBS) of n2processors, the nearest neighbor problem can be solved in O(loglogn) time, and using an LARPBS of n2+εprocessors, for any fixed constant ε>0. the nearest neighbor problem can be solved in O(l) time. We also show that the nearest neighbor problem can be solved on an LARPBS of n2processors in O(1) time with high probability.
In this paper we present two advanced methods for evolutionary optimisation. One method is based on parallel Genetic algorithms. It is called Cooperating Populations with Different Evolution Behaviours (CoPDEB), and a...
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In this paper we present two advanced methods for evolutionary optimisation. One method is based on parallel Genetic algorithms. It is called Cooperating Populations with Different Evolution Behaviours (CoPDEB), and allows each population to exhibit a different evolution behaviour. Results from two problems show the advantage of using different evolution behaviour on each population. The other method concerns application of GAs on constrained optimisation problems. It is called the Varying Fitness Function (VFF) method and implements a fitness function with varying penalty tenns, added to the objective function for penalising infeasible solutions, in order to assist the GA to easily locate the area of the global optimum. Simulation results on two real world problems show that the VFF method outperfonns the classic static fitness function implementations.
On the basis of the geological background of Tarim foreland basin, this paper realizes parallel three-dimensional forward modeling in Kuqa area by using three-dimensional arbitrary difference precise integration algor...
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On the basis of the geological background of Tarim foreland basin, this paper realizes parallel three-dimensional forward modeling in Kuqa area by using three-dimensional arbitrary difference precise integration algorithm. Compared with the conventional differential method, the three-dimensional arbitrary difference precise integration algorithm has greatly improved the precision by using local integral semi-analytical method in time domain to obtain the recursion operator of wave equations. In this paper, according to the actual examples analysis, the stability of calculation gets better owing to the stable factor constraints; by using an improved adaptive absorbing boundary and the parallelization of serial program, the time consuming of three-dimensional forward modeling is greatly reduced and a large amount of three-dimensional forward modeling is finished.
In imperative programming languages, the more complicated a problem is, the more difficult extracting parallelism becomes. On the other hand, it can be said that declarative programming languages are suited to paralle...
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In imperative programming languages, the more complicated a problem is, the more difficult extracting parallelism becomes. On the other hand, it can be said that declarative programming languages are suited to parallelism extraction. The equivalent transformation (ET) programming language used in this study is a type of declarative programming language and is based on the ET computation model. The ET programming language is superior to other declarative programming languages in terms of guaranteeing independence, correctness and granularity of the rules that a program consists of as well as the correctness of its computing results (including parallel computing). To demonstrate the effectiveness of parallelism based on the ET computation model, it is essential to introduce the traditional concepts of And-parallelism and Or-parallelism in this study. Through the introduction of these concepts, this paper proposes And-parallelism, Or-parallelism and And Or-parallelism based on the ET computation model. Then, using these parallel algorithms, a number-place problem, a type of constraint satisfaction problem (CSP), is solved and, by comparing the computation results, the characteristics of each algorithm are analyzed.
Malware analysis is a major challenge in cybersecurity due to the regular appearance of new malware and its effect in cyberspace. The existing tools for malware analysis enable reverse engineering to understand the or...
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Malware analysis is a major challenge in cybersecurity due to the regular appearance of new malware and its effect in cyberspace. The existing tools for malware analysis enable reverse engineering to understand the origin, purpose, attributes, and potential consequences of malicious software. An entropy method is one of the techniques used to analyze and detect malware, which is defined as a measure of information encoded in a series of values based upon the probability of those values appearing. The window entropy algorithm is one of the methods that can be applied to calculate entropy values in an effective manner. However, it requires a significant amount of time when the size of the file is large. In this paper, we solve this problem in two ways. The first way of improvement is determining the best window size that leads to minimizing the running time of the window entropy algorithm. The second way of improvement is by parallelizing the window entropy algorithm on a multicore system. The experimental studies using artificial data show that the improved sequential algorithm can reduce the window entropy method's running time by 79% on an average. Also, the proposed parallel algorithm outperforms the modified sequential algorithm by 77% and has super-linear speed up.
An efficient parallel global router using random optimization that is independent of net ordering is *** approaches are described and strategies guaranteeing the routing quality are *** wire length model is implemente...
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An efficient parallel global router using random optimization that is independent of net ordering is *** approaches are described and strategies guaranteeing the routing quality are *** wire length model is implemented on multiprocessor,which enables the algorithm to approach feasibility of large scale *** driven model on multiprocessor and wire length model on distributed processors are also *** parallel algorithm greatly reduces the run time of *** experimental results show good speedups with no degradation of the routing quality.
We present a simple systolic algorithm for implementing dictionary machine based on the VLSI technology. Our design makes use of a dynamic. global tree rebalancing scheme to attain high system throughput. Our scheme i...
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We present a simple systolic algorithm for implementing dictionary machine based on the VLSI technology. Our design makes use of a dynamic. global tree rebalancing scheme to attain high system throughput. Our scheme is simple to implement and requires low sophistication in the design of processing nodes. Results from analysis and simulation show that our algorithm has optimal response time and achieves an average latency close to 1. This represents a significant improvement over many of the previous designs. Unlike most parallel dictionary machines reported in the literature, our approach requires no compression operations.
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