• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2000년도 가을 학술발표회논문집
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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.

• Structural Engineering and Mechanics
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• 제32권1호
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• pp.95-126
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• 2009

The present contribution addresses the parallelization of advanced simulation methods for structural reliability analysis, which have recently been developed for large-scale structures with a high number of uncertain parameters. In particular, the Line Sampling method and the Subset Simulation method are considered. The proposed parallel algorithms exploit the parallelism associated with the possibility to simultaneously perform independent FE analyses. For the Line Sampling method a parallelization scheme is proposed both for the actual sampling process, and for the statistical gradient estimation method used to identify the so-called important direction of the Line Sampling scheme. Two parallelization strategies are investigated for the Subset Simulation method: the first one consists in the embarrassingly parallel advancement of distinct Markov chains; in this case the speedup is bounded by the number of chains advanced simultaneously. The second parallel Subset Simulation algorithm utilizes the concept of speculative computing. Speedup measurements in context with the FE model of a multistory building (24,000 DOFs) show the reduction of the wall-clock time to a very viable amount (<10 minutes for Line Sampling and ${\approx}$ 1 hour for Subset Simulation). The measurements, conducted on clusters of multi-core nodes, also indicate a strong sensitivity of the parallel performance to the load level of the nodes, in terms of the number of simultaneously used cores. This performance degradation is related to memory bottlenecks during the modal analysis required during each FE analysis.

• 한국터널공학회:학술대회논문집
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• 한국터널공학회 2005년도 학술발표회 논문집
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• pp.225-232
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• 2005

The construction of parallel tunnel by using the shield TBM method was increased recently. Accordingly the application and the propriety of the parallel shield TBM tunnels were studied through domestic and foreign construction cases herein. Also the behavior of tunnel structure and ground was evaluated by a numerical analysis with various ground conditions and the distance between the parallel tunnels. As a result, it was concluded that a deep investigation as well as a ground reinforcement was required with a ratio(L/D) of the distance between the parallel tunnels(L) to tunnel outer diameter(D) less than 0.5 because the Interference phenomenon was expected to occur. And the appropriateness of the application method of parallel shield TBM tunnel was validated through the 2-dimensional numerical analysis simulated the process of excavation after the ground reinforcement in the starting area of the OOO construction site with the ratio(L/D) of 0.35.

• 한국자동차공학회논문집
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• 제16권6호
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• pp.26-32
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• 2008

This research presents a simulation for the fuel economy of parallel diesel hybrid vehicle. Diesel engines compared to gasoline engines have the advantages of higher fuel economy and lower $CO_2$ emission. One of the most ways to meet future fuel economy and emissions regulation is to combine diesel engine technology with a hybrid electric vehicle. The simulation of HEV is growing need for rapid analysis of the many configurations and component options. WAVE, a one-dimensional engine analysis tool, was used to a 2.7L diesel engine. ADVISOR, designed for rapid analysis of the performance and fuel economy of vehicle models, was used to conventional and hybrid electric vehicle by the use of output file from WAVE as the input engine data file for ADVISOR. A parallel diesel HEV is at least $19.7{\sim}36%$ higher fuel economy and improved acceleration ability compared to a conventional diesel vehicle. The energy loss of the parallel diesel HEV is $23{\sim}38%$ less than the conventional vehicle using regeneration.

• 전기학회논문지P
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• 제51권2호
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• pp.55-59
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• 2002

Parallel processing is able to be used effectively on computationally intense power system problems. But this technology is not still available is not only parallel computer but also parallel processing scheme. Testing these algorithms to ensure accuracy, and evaluation of their performance is also an issue. Although a significant amount of parallel algorithms of power system problem have been developed in last decade, actual testing on parallel computer architectures lies in the beginning stages because no clear cut paths. This paper presents Jacobian modeling method to supply the base being able to treat power flow by newton's method by the computer. This method is to assign and to compute teared blocks of sparse matrix at each parallel processors. The testing to insure accuracy of developed method have been done on serial computer by trying to simulate a parallel environment.

• 응용통계연구
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• 제21권4호
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• pp.695-704
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• 2008

평행좌표그림은 다변량자료를 시각화하는 하나의 방법이다. 평행좌표그림은 4차원 이상의 직각좌표계 표시의 어려움을 극복할 수 있는 그림이다. 그러나 변수 축의 배열에 따라 같은 자료에 대하여도 다른 해석이 가능하다. 변수 선택 문제를 해결하는 한 가지 방법으로서 우리는 정다각기둥평행좌표그림을 제안할 수 있다.

• 한국멀티미디어학회논문지
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• 제4권6호
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• pp.579-587
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• 2001

본 논문은 그래픽 사용자 인터페이스를 이용하여 병렬 프로그래밍 환경을 설계하고 구현하였다. 병렬 프로그램은 다양한 하드웨어의 특성에 따라 또는 프로그램의 특성에 따라 사용자가 병렬 프로그램을 작성하여야 하기 때문에 사용자가 병렬 프로그램을 작성하는 것은 매우 어렵다. 본 논문에서는 이런 문제를 도와주기 위하여 기존의 병렬 컴파일러에서 제공되고 있는 텍스트 위주의 병렬화 정보 대신에 그래픽 사용자 인터페이스를 이용하여 편안하고 쉽게 병렬화 정보를 제공하는 병렬 프로그래밍 환경을 제안하고, 구현하였다. 본 논문의 병렬 프로그래밍 환경은 종속성 분석, CFG, HTG, 루프 병렬화 등의 기능을 제공한다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.302-307
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• 2005

Recently, lots of parallel mechanisms for spatial 3-DOF and 6-DOF were investigated. However, research on 4-DOF and 5-DOF parallel mechanisms has been very few. In this paper, we propose a 4-DOF parallel mechanism that consists of 3-rotational and 1-translational motions. The kinematic characteristics of this mechanism are analyzed in terms of an isotropic index and maximum force transmission ratio, and its kinematic optimization is being conducted to ensure enhanced kinematic performances

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2000년도 춘계학술대회 논문집
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• pp.672-675
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• 2000

There are many sources of errors in the parallel device. This study investigates the effect of a clearance error at a U-joint on the position and orientation errors of the platform of a new parallel device, cubic parallel manipulator. In this study, the limits of errors can be estimated for given conditions.

• 응용통계연구
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• 제9권1호
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• pp.45-52
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• 1996

자료의 구조와 특징을 파악하기 위한 탐색적 자료분석을 행할 때 유용한 수단으로 통계 그래픽스가 이용된다. 평행좌표그림(parallel coordinate plot)을 통계 그래픽스의 한 방법인 동적 그래픽스로서 이용하기 위하여 동적 평행좌표그림이 쓰이는데, 이 도구를 이용하면 3차원 이상의 다차원 자료를 동적 그래픽스로 표현, 분석할 수 있다. 본 논문에서는 하나의 동적 평행좌표그림을 제시하고, 자료분석의 예를 보였다.