• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.12
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• pp.1-10
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• 1994

In this paper, we propose a processor allocation algorithm using the PGG(Packed Gray code Group) for the MIMD hypercube. The number of k-D subcubes in an n-cube is C(n.k) en-k. When the PGG is employed in the processor allocation, C(n, k) PGG's are required to recognize all the k-D subcubes in an n-cube. from the simulation we find that the capability of processor allocation using only 40% of C(n, k) PGG's is about the same as that of the allocation using all the PGG's.

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.430-433
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• 1999

Woo[8]proposed dual-token based fault-tolerant scheduling algorithm in multiprocessor environment for resolving the problem of old systems that have a central dispatcher processor. However, this algorithm does not present token allocation algorithm in detail when central dispatcher processor has failed. In this paper, we propose a fault detection algorithm and processor selection algorithm for token allocation when central dispatcher processor has failed.

• Journal of Electrical Engineering and information Science
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• v.1 no.1
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• pp.129-139
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• 1996

The processor allocation problem in mesh multicamputers is to recognize and locate a free submesh that can accommodate a request for a submesh of a specified size. An efficient submesh allocation strategy is required for achieving high performance on mesh multicomputers. In this paper, we propose a new best-fit submesh allocation strategy for mesh multicomputers. The proposed strategy maintains and uses a free submesh list to get global information for free submeshes. For an allocation request the proposed strategy tries to allocate a best-fit submesh which causes the least amount of potential processor fragmentation so as to preserve the large free submeshes as many as possible for later requests. For this purpose, we introduce a novel function for quantifying the degree of potential fragmentation of submeshes. The proposed strategy has the complete submesh recognition capability. Extensive simulation is carried out t compare the proposed strategy with the previous strategies and experimental results indicate that the proposed strategy exhibits the best performance along with about 10% to 30% average improvement over the best previous strategy.

• IE interfaces
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• v.17 no.4
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• pp.466-471
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• 2004

In this paper, I develop a simple dynamic resource allocation algorithm that reduces the call blocking rate by improving the resource utilization of the WCDMA (Wideband Code Division Multiple Access) systems under multimedia service environment. Simulation results show that the proposed algorithm significantly reduces the blocking rate of high speed multimedia calls. The algorithm developed in this paper is currently working in the commercial WCDMA IMT-2000 system.

• The KIPS Transactions:PartA
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• v.12A no.4 s.94
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• pp.281-288
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• 2005

Efficient utilization of processing resources in a large multicomputer system with the possibility of fault occurrence depends on the reliable processor management scheme. This paper presents a dynamic and reliable processor allocation strategy to increase the performance of mesh-connected parallel systems with faulty processors The basic idea is to reconfigure a faulty mesh system into a maximum convex system using the fault-free upper or lower boundary nodes to compensate for the non-boundary faulty nodes. To utilize the non-rectangular shaped system parts, our strategy tries to allocate L-shaped submeshes instead of signaling the allocation failure. Extensive simulations show that the strategy performs more efficiently than other strategies in terms of the job response time md the system utilization.

• Journal of Internet Computing and Services
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• v.12 no.6
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• pp.1-17
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• 2011

The performance of DHCS depends on the algorithm which schedules input DAG. However, as the task scheduling problem in DHCS is an NP-complete problem, heuristic approach has to be made. Task scheduling algorithm consists of task prioritizing phase and processor allocation phase, and most of studies are considering both phases together. In this paper, we focus on task prioritizing phase and propose a WPD algorithm which is optimized for task duplication based processor allocation method. For an evaluation of the proposed WPD algorithm, we combined WPD algorithm with processor allocation phase of HMPID, HCPFD, HCT algorithms, which are using task duplication based processor allocation method. The results show that WPD algorithm makes a better use of task duplication than conventional task prioritizing methods and provides 9.58% better performance than HCPFD algorithm, 1.31% than HCT algorithm.

• Journal of the Korea Society for Simulation
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• v.3 no.1
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• pp.43-53
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• 1994

With remarkable progress of hardware technologies, multiprocessor systems equipped with thousands of processors will be available in near future. In order to increase the performance of these systems, many processor allocation algorithms have been proposed. However, few studies have been conducted in order to compare the performance of these algorithms. In this paper, simulation techniques are used in order to compare the performance of the processor allocation algorithms proved to be useful. These are: an algorithm using equipartion, an algorithm using average parallelism, an algorithm using execution signatures, and an algorithm using the number of tasks in a task precedence graph. Simulation shows that the algorithm using execution signatures performs best while the algorithm using average parallelism performs worst with small allocated processors. Surprisingly, the algorithm using equipartition performs well despite the fact that it has smallest overhead. Overall, it can be recommended that the algorithm using equipartition be used without any execution history and that the algorithm using execution signatures be used with some execution history.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.30B no.4
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• pp.27-36
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• 1993

This paper proposes a shortest path allocation algorithm over the processors on the hypercube system based on the message passing techniques with the optimized module allocation. On multiprocessor systems, how to divide one task into multiple tasks efficiently is an important issue due to the hardness of the life cycle estimation of each process. To solve the life cycle discrepancies, the appropriate task assignment to each processor and the flexible communications among the processors are indispensible. With the concurrent program execution on hypercube systems, each process communicaties to others with the method of message passing. And, each processor has its own memory. The proposed algorithm generates a callable tree out of the module, assigns the weight factors, constructs the allocation graph, finds the shortest path allocation tree, and maps them with hypercube.

• Journal of KIISE:Computer Systems and Theory
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• v.37 no.2
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• pp.76-89
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• 2010

The performance of Distributed Heterogeneous Computing System depends on the algorithm which schedules input DAG graph. Among various scheduling algorithms, list scheduling algorithm provides superior performance with low complexity. List scheduling consists of task prioritizing phase and processor allocation phase, but most studies only focus on task prioritizing phase. In this paper, we propose LIP policy which has the same complexity with traditional allocation policies but has superior performance. The performance of LIP has been observed by applying them to task prioritizing phase of traditional list scheduling algorithms, HCPT, HEFT, GCA, and PETS. The results show that LIP has better performance than insertion-based policy and non-insertion-based policy, which are traditional processor allocation policies.

• Journal of the Korean Institute of Intelligent Systems
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• v.10 no.5
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• pp.409-416
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• 2000

In the shared-memory mutiprocessor systems, shared processing techniques such as time-sharing, space¬sharing, and gang-scheduling are used to improve the overall system utilization for the parallel operations. Recently, LLPC(Loop-Level Process Control) allocation technique was proposed. It dynamically adjusts the needed number of processors for the execution of the parallel code portions based on the current system load in the given job. This method allocates as many available processors as possible, and does not save any processors for the parallel sections of other later-arriving applications. To solve this problem, in this paper, we propose a new processor allocation technique called FPA(Fuzzy Processor Allocation) that dynamically adjusts the number of processors by fuzzifYing the amounts ofueeded number of processors, loads, and estimated execution times of job. The proposed method provides the maximum possibility of the parallism of each job without system overload. We compare the performances of our approaches with the conventional results. The experiments show that the proposed method provides a better performance.