• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.405-406
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• 2006

Recently, the flat display modules such as plasma or TFT-LCD employ thin crystallized panels which are normally weak to high level transient mechanical energy inputs. As a result, anti-shock performance is one of the most important design specifications for TFT-LCD modules. However, most of large display module designs are generated based on engineers own experiences. Also, a large-scale analysis to evaluate complex material and structural behaviors is one of interesting topic in diverse engineering and scientific fields. The utilization of massively parallel processors has also been a recent trend of high performance computing. The objective of this paper is to introduce a parallel process system which consists of general purpose finite element analysis solver as well as parallelized PC cluster. The parallel processing system is constructed using thirty-two processing elements and the finite element program is developed by adopting hierarchical domain decomposition method. In order to verify the efficiency of the established system, an impact analysis on thin and complex sub-parts of flat display modules is performed. The evaluation results showed a good agreement with the corresponding reference solutions, and thus, the parallel process system seems to be a useful tool fur the complex structural analysis such as IT related products.

• KIEE International Transactions on Power Engineering
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• 제5A권2호
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• pp.116-124
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• 2005

This paper presents an application of the parallel Genetic Algorithm-Tabu Search (GA- TS) algorithm, and that is to search for an optimal solution of a reconfiguration in distribution systems. The aim of the reconfiguration of distribution systems is to determine the appropriate switch position to be opened for loss minimization in radial distribution systems, which is a discrete optimization problem. This problem has many constraints and it is very difficult to solve the optimal switch position because of its numerous local minima. This paper develops a parallel GA- TS algorithm for the reconfiguration of distribution systems. In parallel GA-TS, GA operators are executed for each processor. To prevent solution of low fitness from appearing in the next generation, strings below the average fitness are saved in the tabu list. If best fitness of the GA is not changed for several generations, TS operators are executed for the upper 10$\%$ of the population to enhance the local searching capabilities. With migration operation, the best string of each node is transferred to the neighboring node after predetermined iterations are executed. For parallel computing, we developed a PC-cluster system consisting of 8 PCs. Each PC employs the 2 GHz Pentium IV CPU and is connected with others through switch based rapid Ethernet. To demonstrate the usefulness of the proposed method, the developed algorithm was tested and is compared to a distribution system in the reference paper From the simulation results, we can find that the proposed algorithm is efficient and robust for the reconfiguration of distribution system in terms of the solution quality, speedup, efficiency, and computation time.

• 전자공학회논문지A
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• 제31A권4호
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• pp.30-38
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• 1994

In this paper, we propose the parallel scrambling technique which is applicable in the multibit-interleaved multiplexing environment. For this, we introduce the concept of SSRG (simple shift register generator) and MSRG(modular shift register generator), and investigate their properties. We also introduce the concept of PSRG(parallel shift register generator) - parallel form of shift register generator, and consider realizations of PSRGs based on SSRGs and MSRGs. Finally, we show how to apply PSRGs to the parallel scrambling for the SDH system.

• 한국시뮬레이션학회논문지
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• 제2권1호
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• pp.31-44
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• 1993

Zeigler's DEVS(Discrete Event Systems Specification) formalism supports formal specification of discrete event systems in a hierarchical , modular manner. Associated are hierarchical, distributed simulation algorithms, called abstract simulators, which interpret dynamics of DEVS models. This paper deals with performance evaluation of P-DEVSIM ++, a parallel simulation environment which implements the DEVS formalism and associated simulation algorithms in a parallel environment. Performance simulator has been developed and used to experiment models of parallel simulation executions in different conditions. The experimental result shows that simulation time depends on both the number of processors in the parallel system and the communication overheads among such processors.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2006년도 학술발표회 논문집
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• pp.1176-1181
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• 2006

본 연구에서는 병렬구조를 가진 안동댐과 임하댐에 대하여 할당법칙(Allocation rule, AR)을 이용하여 용수공급해석과 신뢰도지표를 산정하였다. 할당계수의 분석결과로는 안동댐이 용수공급의 기여도가 임하댐과 비교해서 Rule(A), Rule(B)에서는 66%이상으로 분석되었으며, Rule(C)의 경우 거의 대등한 기여를 하는 것으로 분석되었다. Rule(C)의 경우는 안동댐과 임하댐의 각각의 저류상태와 공급능력 상태에 따라 저류량과 유입량의 합을 댐의 평균저류량으로 나눈 비에 의해 공급량이 할당되어서 우수한 결과를 나타내었다. 병렬저수지 시스템의 용수공급의 분석기준에 있어 월별로 일정한 양을 기준으로 분석하는 것보다는 월별 용수변화량을 고려한 경우가 용수공급분석에 있어 우수한 결과를 나타나는 것으로 분석되었다. 본 연구를 기초로 하여 용수공급해석을 위한 새로운 기법이 개발되어 병렬저수지에 적용되었으며, 이 운영규칙은 여러 종류의 병렬저수지 시스템의 적용에 있어 효율적인 운영방안을 수립할 수 있을 것이다.

• 한국공간정보시스템학회 논문지
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• 제7권2호
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• pp.81-89
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• 2005

디클러스터링과 병렬 색인 구조는 효과적인 대용량 데이터의 검색을 위한 데이터베이스의 중요한 연구 분야이다. 기존의 연구에서 다중 디스크에서 다양한 방법들을 이용하여 R-tree등의 색인을 위한 다양한 방법들이 제시되었으나, 이에 적절한 검색 기법에 관한 연구는 거의 없었다. 이 연구에서는 기존의 연구에서 제시된 병렬 공간 색인 구조에서 검색 성능을 향상시킬 수 있는 새로운 검색 기법을 제시한다. 제시된 기법은 디스크로부터 동시에 여러 개의 노드를 읽어 들일 수 있는 병렬 디스크의 장점을 최대한 활용한 기법이다. 기존의 한번에 한 노드를 읽는 알고리즘을 개선하여 여러 노드를 동시에 접근하기 위한 최적화된 기법이다 실험을 통하여 제시된 기법은 기존의 연구에서 제시된 알고리즘들을 검색 기법의 변경을 통하여 최대 40%이상의 성능 향상을 유발함을 입증하였다.

• 전기학회논문지
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• 제66권7호
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• pp.1059-1065
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• 2017

In this paper, the energy harvester with a piezoelectric materials is modeled as the electric equivalent circuit, and performances of a standard DC method and a Parallel-SSHI method are verified through experiment under variable force and load conditions. Piezoelectric generator consists of mass, damper and spring constant, and it is modeled by electrical equivalent circuit with RLC components. Standard DC and Parallel-SSHI are used as power conversion methods, and standard DC consists of full-bridge rectifier and smoothing capacitor. Parallel-SSHI method is composed of L-C resonant circuit, zero-crossing detector and full-bridge rectifier. In case of simulation under $100k{\Omega}$ load condition, the harvested power is $500{\mu}W$ in Standard DC and $670{\mu}W$ in Parallel-SSHI, respectively. In experiment, the harvested power under $100k{\Omega}$ load condition is $420{\mu}W$ in standard DC and $602{\mu}W$ in Parallel-SSHI. Harvested power of Parallel-SSHI is improved by approximately 40% more than that of standard DC method.

• 한국산학기술학회논문지
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• 제11권3호
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• pp.991-996
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• 2010

본 논문에서는 IEEE 1284 동작 모드를 사용하는 병렬 I/O 제어 시스템을 제안하고 인터넷 환경하에서 원격제어 통신을 실현하였다. IEEE 1284 표준은 다수의 특정한 동작 모드와 호환성이 있는 인터페이스를 정의하며 PC의 병렬 포트에 대해 보다 개선된 성능을 제공한다. 병렬 포트 장치는 Device/ID 식별 절차를 갖는 병렬 포트에 대해 PnP 기능을 제공하게 되는 새로운 운영체제 때문에 시스템 구성과 인터페이스 절차가 간단하게 된다. 이러한 성능 증대로 병렬 I/O 포트는 더욱 저가격, 실용이 간편한 I/O 포트로 가능하게 된다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 추계종합학술대회 논문집
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• pp.727-730
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• 1998

In this paper, we propose an implementation of an efficient parallel Radon transform on TMS320C80-based system. For an N$\times$N SAR image, we can obtain O(NM/p) of the conventional parallel Radon transform, by representing the projection patterns in Radon space variables instead of the image space variables, and pipelining the algorithm, where p is the number of processors and M is the number of projection angles. Also, we can reduce the time for the dynamic load distribution among the nodes and the communication overheads of accessing the global memories, by pipelining the memory and processing operations by using tripple buffer structure. Experimental results show an efficient parallel Radon transform of speedup Sp=3.9 and efficiency E=97.5% for 256$\times$256 image, when implemented on TMS320C80 composed of four parallel slave processors with three memory blocks.

• 전기학회논문지
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• 제57권10호
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• pp.1688-1695
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• 2008

Recently, it is common in a distribution system of Korea Electric Power Corporation (KEPCO) to find instances where distribution lines are parallel. A traditional method of an induced voltage calculation is not suitable for parallel distribution lines. For more actual analysis of induced voltage on telecommunication lines in parallel distribution lines, a new calculation method is needed. This paper presents a new calculation method of an induced voltage on telecommunication line using equivalent ${\pi}$ circuits matrix in parallel distribution lines. The advantages of the calculation method are using actual neutral current value and not using screening factor for considering the overhead ground wire and the neutral wire. To verify the effectiveness and the accuracy of the method, various case studies are performed with EMTP(Electro-Magnetic Transients Program).