• Title, Summary, Keyword: Parallel Computing

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A Study on the Performance of Parallelepiped Classification Algorithm (평행사변형 분류 알고리즘의 성능에 대한 연구)

  • Yong, Whan-Ki
    • Journal of the Korean Association of Geographic Information Studies
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    • v.4 no.4
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    • pp.1-7
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    • 2001
  • Remotely sensed data is the most fundamental data in acquiring the GIS informations, and may be analyzed to extract useful thematic information. Multi-spectral classification is one of the most often used methods of information extraction. The actual multi-spectral classification may be performed using either supervised or unsupervised approaches. This paper analyze the effect of assigning clever initial values to image classes on the performance of parallelepiped classification algorithm, which is one of the supervised classification algorithms. First, we investigate the effect on serial computing model, then expand it on MIMD(Multiple Instruction Multiple Data) parallel computing model. On serial computing model, the performance of the parallel pipe algorithm improved 2.4 times at most and, on MIMD parallel computing model the performance improved about 2.5 times as clever initial values are assigned to image class. Through computer simulation we find that initial values of image class greatly affect the performance of parallelepiped classification algorithms, and it can be improved greatly when classes on both serial computing model and MIMD parallel computation model.

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Parallel Computing Environment based on Windows Operating System (Windows 운영체제 기반의 병렬 계산 환경)

  • Choe, Jeong Yeol;Sin, Jae Ryeol;Kim, Myeong Ho
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.31 no.4
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    • pp.16-25
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    • 2003
  • A parallel computing environment based on Windows operating system was constructed and a performance test was mode in comparison with Linux based systems. The Windows 2000 cluster was composed with servers and clients connected by Fast-ethernet, within which two sub-clusters may operates together or separately. Compaq Visual Fortran complier and two MPI libraries, MPICH.NT.1.2.2 and NT-MPICHNT.1.2 were installed as computing tools. Parallel computing performance tests were carried out using two-dimensional preconditioned Navier-Stokes code to examine the dependency on the number of processors, problem size and MPI libraries, those were compared with results from Linux clusters. Results shows that a cluster based on the user-friendly Windows operating system is also useful for the parallel computing and has good performance comparable to the previous Linux clusters.

Development of Parallel Algorithm for Dynamic Analysis of Three-Dimensional Large-Scale Structures (3차원 대형구조물의 동적해석을 위한 병렬 알고리즘 개발)

  • 김국규;성창원;박효선
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • pp.307-314
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    • 2000
  • A parallel condensation algorithm for efficient dynamic analysis of three-dimensional large-scale structures is presented. The algorithm is developed for a user-friendly and cost effective high-performance computing system on a collection of Pentium processors connected via a 100 Mb/s Ethernet LAN. To harness the parallelism in the computing system effectively, a large-scale structure is partitioned into a number of substructures equal to the number of computers in the computing system Then, for reduction in the size of an eigenvalue problem the computations required for static condensation of each substructure is processed concurrently on each slave computer. The performance of th proposed parallel algorithm is demonstrated by applying to dynamic analysis of a three dimensional structure. The results show that how the parallel algorithm facilitates the efficient use of a small number of low-cost personal computers for dynamic analysis of large-scale structures.

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Real time simulation using multiple DSPs for fossil power plants (병렬처리를 이용한 화력발전소의 실시간 시뮬레이션)

  • 박희준;김병국
    • 제어로봇시스템학회:학술대회논문집
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    • pp.480-483
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    • 1997
  • A fossil power plant can be modeled by a lot of algebraic equations and differential equations. When we simulate a large, complicated fossil power plant by a computer such as workstation or PC, it takes much time until overall equations are completely calculated. Therefore, new processing systems which have high computing speed is ultimately needed to develope real-time simulators. Vital points of real-time simulators are accuracy, computing speed, and deadline observing. In this paper, we present a enhanced strategy in which we can provide powerful computing power by parallel processing of DSP processors with communication links. We designed general purpose DSP modules, and a VME interface module. Because the DSP module is designed for general purpose, we can easily expand the parallel system by just connecting new DSP modules to the system. Additionally we propose methods about downloading programs, initial data to each DSP module via VME bus, DPRAM and processing sequences about computing and updating values between DSP modules and CPU30 board when the simulator is working.

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Modified GOMS-Model for Mobile Computing (모바일 작업을 위한 수정된 GOMS-model에 대한 연구)

  • Lee, Suk-Jae;Myung, Ro-Hae
    • Journal of the Society of Korea Industrial and Systems Engineering
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    • v.32 no.2
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    • pp.85-93
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    • 2009
  • GOMS model is a cognitive modeling method of human performance based on Goal, Operators, Methods, Selection rules. GOMS model was originally designed for desktop environment so that it is difficult for GOMS model to be implemented into the mobile environment. In addition, GOMS model would be inaccurate because the original GOMS model was based on serial processing, excluding one of most important human information processing characteristics, parallel processing. Therefore this study was designed to propose a modified GOMS model including mobile computing and parallel processing. In order to encompass mobile environment, an operator of 'look for' was divided into 'visual move to' and 'recognize' whereas 'point to' and 'click' were combined into 'tab.' The results showed that newly introduced operators were necessary to estimate more accurate mobile computing behaviors. In conclusion, modified-GOMS model could predict human performance more accurately than the original GOMS model in the mobile computing environment.

Optimal Design of a Direct-Driven PM Wind Generator Aimed at Maximum AEP using Coupled FEA and Parallel Computing GA

  • Jung, Ho-Chang;Lee, Cheol-Gyun;Hahn, Sung-Chin;Jung, Sang-Yong
    • Journal of Electrical Engineering and Technology
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    • v.3 no.4
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    • pp.552-558
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    • 2008
  • Optimal design of the direct-driven Permanent Magnet(PM) wind generator, combined with F.E.A(Finite Element Analysis) and Genetic Algorithm(GA), has been performed to maximize the Annual Energy Production(AEP) over the entire wind speed characterized by the statistical model of wind speed distribution. Particularly, the proposed parallel computing via internet web service has contributed to reducing excessive computing times for optimization.

Parallel LDPC Decoder for CMMB on CPU and GPU Using OpenCL (OpenCL을 활용한 CPU와 GPU 에서의 CMMB LDPC 복호기 병렬화)

  • Park, Joo-Yul;Hong, Jung-Hyun;Chung, Ki-Seok
    • IEMEK Journal of Embedded Systems and Applications
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    • v.11 no.6
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    • pp.325-334
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    • 2016
  • Recently, Open Computing Language (OpenCL) has been proposed to provide a framework that supports heterogeneous computing platforms. By using an OpenCL framework, digital communication systems can support various protocols in a unified computing environment to achieve both high portability and high performance. This article introduces a parallel software decoder of Low Density Parity Check (LDPC) codes for China Multimedia Mobile Broadcasting (CMMB) on a heterogeneous platform. Each step of LDPC decoding has different parallelization characteristics. In this paper, steps suitable for task-level parallelization are executed on the CPU, and steps suitable for data-level parallelization are processed by the GPU. To improve the performance of the proposed OpenCL kernels for LDPC decoding operations, explicit thread scheduling, loop-unrolling, and effective data transfer techniques are applied. The proposed LDPC decoder achieves high performance by using heterogeneous multi-core processors on a unified computing framework.

Fuzzy Inference of Large Volumes in Parallel Computing Environments (병렬컴퓨팅 환경에서의 대용량 퍼지 추론)

  • 김진일;이상구
    • Journal of Korean Institute of Intelligent Systems
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    • v.10 no.4
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    • pp.293-298
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    • 2000
  • In fuzzy expert systems or database systems that have volumes of fuzzy data or large fuzzy rules, the inference time is much increased. Therefore, a high performance parallel fuzzy computing environment is needed. In this paper, we propose a parallel fuzzy inference mechanism in parallel computing environments. In this, fuzzy rules are distributed and executed simultaneously. The ONE_TO_ALL algorithm is used to broadcast the fuzzy input input vector to the all nodes. The results of the MIN/MAX operations are transferred to the output processor by the ALL_TO_ONE algorithm. By parallel processing of fuzzy or data, the parallel fuzzy inference algortihm extracts effective and achieves and achieves a good speed factor.

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Parallel Computing of Large Scale FE Model based on Explicit Lagrangian FEM (외연 Lagrangian 유한요소법 기반의 대규모 유한요소 모델 병렬처리)

  • 백승훈;김승조;이민형
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.34 no.8
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    • pp.33-40
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    • 2006
  • A parallel computing strategy for finite element(FE) processing is described and implemented in nonlinear explicit FE code and its parallel performances are evaluated. A self-made linux-cluster supercomputer with 520 CPUs is used as a bench mark test bed. It is observed that speed-up is increased almost idealy even up to 256 CPUs for a large scale model. A communication over head and its effect on the parallel performance is also examined. Parallel performance is compare with the commercial code and developed code shows superior performance as the number of CPUs used are increased.

High Performance Computing: Infrastructure, Application, and Operation

  • Park, Byung-Hoon;Kim, Youngjae;Kim, Byoung-Do;Hong, Taeyoung;Kim, Sungjun;Lee, John K.
    • Journal of Computing Science and Engineering
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    • v.6 no.4
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    • pp.280-286
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    • 2012
  • The last decades have witnessed an increasingly indispensible role of high performance computing (HPC) in science, business and financial sectors, as well as military and national security areas. To introduce key aspects of HPC to a broader community, an HPC session was organized for the first time ever for the United States and Korea Conference (UKC) during 2012. This paper summarizes four invited talks that each covers scientific HPC applications, large-scale parallel file systems, administration/maintenance of supercomputers, and green technology towards building power efficient supercomputers of the next generation.