• 한국항공우주학회지
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• 제46권2호
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• pp.133-140
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• 2018

본 논문에서는 복합재 적층 구조물의 면내 구조 해석을 위한 자동화 소프트웨어를 개발한다. 개발된 소프트웨어는 다양한 파손 기준을 제공하며 사용자의 편리성을 고려하여 해석 결과를 출력한다. 또한 병렬처리 기법에 기반한 일괄 처리 해석(batch job analysis) 기능을 지원한다. 구현된 소프트웨어의 성능을 검증하기 위하여 소프트웨어에서 계산된 안전 여유와 자체적으로 사용 중인 in-house 방식과 실제 시편 실험에서 얻어진 안전 여유간의 비교를 수행하였다. 비교 결과 in-house 방식과는 0.01 이하의 오차가 있었으며 시편 실험과는 약 ${\pm}10%$ 이내의 오차가 존재함을 확인하였다. 또한 병렬처리 기법을 적용한 일괄 처리 해석 작업의 실행 속도 개선을 확인하였다.

• 제어로봇시스템학회논문지
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• 제6권1호
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• pp.81-90
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• 2000

Parallel manipulator is suitable for the high precise task because it than has higher stiffness, larger load capacity and more excellent precision, due to the closed-lop structure, than serial manipulator. But the controller design for parallel manipulator is difficult because the parallel manipulator has both the complexity of structure and the interference of actuators. The precision improvement of parallel manipulator using a classical linear control scheme is difficult because the parallel manipulator has the tough nonlinear characteristics. In this paper, firstly, the kinematic analysis of a parallel manipulator used at the experiments is performed so as to show the controllability. The analysis of internal singular configuration of the workspace is performed using the kinematic isotropic index so a sto show the limitation of control performance of a simple linear controller with fixed control gains. Secondly, a control scheme is designed by using an adaptive fuzzy logic controller so that active joints of the parallel manipulator track more precisely the desired input trajectory. This adaptive fuzzy logic controller so that active joints of the parallel manipulator track more precisely the desired input trajectory. This adaptive fuzzy logic controller is often used for the control of nonlinear system because it has both the inference ability and the learning ability. Lastly, the effeciency of designed control scheme is demonstrated by the real-time control experiments with IBM PC interface logic H/W and S/W of my won making. The experimental results was a success.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 추계학술대회논문집A
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• pp.818-823
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• 2000

In practical design studies, most of designers solve multidisciplinary problems with complex design structure. These multidisciplinary problems have hundreds of analysis and thousands of variables. The sequence of process to solve these problems affects the speed of total design cycle. Thus it is very important for designer to reorder original design processes to minimize total cost and time. This is accomplished by decomposing large multidisciplinary problem into several multidisciplinary analysis subsystem (MDASS) and processing it in parallel. This paper proposes new strategy for parallel decomposition of multidisciplinary problem to raise design efficiency by using genetic algorithm and shows the relationship between decomposition and multidisciplinary design optimization (MDO) methodology.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제48권6호
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• pp.294-300
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• 1999

There is a growing interest in hybrid electric vehicles due to environmental concerns. Recent efforts are directed toward developing an improved main component systems for the hybrid electric vehicle applications. Soon after the introduction of electric starter for internal combustion engine early this century, despite being energy efficient and nonpolluting, electric vehicle lost the battle completly to internal combustion engine due to its limited range and inferior performance. Hybrid Electric vehicles offer the most promising solutions to reduce the emission of vehicles. This paper describes a method for cost reduction estimation of parallel hybrid electric vehicle. We used a cost reduction structure that consisted of five major subsystems (three-type and two-type motor) for parallel hybrid electric vehicle. Especially, we estimated the potential for cost reductions in parallel hybrid electric vehicle as a function of time using the learning curve. Also, we estimated the potentials of cost by depreciation.

• 전자공학회논문지D
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• 제34D권10호
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• pp.32-38
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• 1997

A characteristic mode analysis of parallel-plate waveguide with finite number of slot as a leaky wav eantenna structure is considered for calculating the characteristics currents, the characteristic patterns, radiatin patterns, and the complex propagation constants. For the cases of 1, 11 and 29 slots, numericl resutls for the equivalent magnetic currents, the radiatin patterns, and thecomplex propagation constants are computed and compared with those obtained by use of the conventional method of moments. Good correspondence between them is observed.

• 국제초고층학회논문집
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• 제4권1호
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• pp.75-83
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• 2015

In the present study, the preliminary results of a large-scale seismic response analysis of a super-high-rise steel frame considering soil-structure interaction are presented. A seismic response analysis under the excitation of the JR Takatori record of the 1995 Hyogoken-Nanbu earthquake is conducted. Precise meshes of a 31-story super-high-rise steel frame and a soil region, which are constructed completely of hexahedral elements, are generated and combined. The parallel large-scale simulation is performed using K computer, which is one of the fastest supercomputers in the world. The results are visualized using an offline rendering code implemented on K computer, and the feasibility of using a very fine mesh of solid elements is investigated. The computation performance of the analysis code on K computer is also presented.

• 한국감성과학회:학술대회논문집
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• 한국감성과학회 2008년도 추계학술대회
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• pp.90-93
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• 2008

In natural language, it is common that repetitive constituents in an expression are to be left out and it is necessary to figure out the constituents omitted at analyzing the meaning of the sentence. This paper is on recognition of boundaries of parallel noun phrases by figuring out constituents omitted. Recognition of parallel noun phrases can greatly reduce complexity at the phase of sentence parsing. Moreover, in natural language information retrieval, recognition of noun with modifiers can play an important role in making indexes. We propose an unsupervised probabilistic model that identifies parallel cores as well as boundaries of parallel noun phrases conjoined by a conjunctive particle. It is based on the idea of swapping constituents, utilizing symmetry (two or more identical constituents are repeated) and reversibility (the order of constituents is changeable) in parallel structure. Semantic features of the modifiers around parallel noun phrase, are also used the probabilistic swapping model. The model is language-independent and in this paper presented on parallel noun phrases in Korean language. Experiment shows that our probabilistic model outperforms symmetry-based model and supervised machine learning based approaches.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.520-524
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• 2004

In this work, a novel spherical 3-dof parallel mechanism is proposed and analyzed. The mechanism consists of three RRPS serial subchains and an additional passive 3-dof type serial subchain. Three RRPS serial subchains alone may form a structure of 6-DOF Stewart Platform mechanism. However, in the proposed mechanism, an additional passive serial subchain acts as constraints to restrict the output motion of the mechanism within 3-DOF spherical space. The closed form solutions of position analysis of the proposed mechanism and its first-order kinematic model are derived. Then its workspace size and kinematic characteristics are examined via kinematic isotropic index.

• Computers and Concrete
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• 제8권1호
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• pp.97-110
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• 2011

In this paper, FEM procedure is applied to the static and dynamic analyses of R/C structures. Simple R/C shell structure is solved by using FEM procedures and the experimental evaluations are performed to represent the applicability of FEM procedure to R/C structures. Also, R/C columns are analyzed numerically and experimentally. On the basis of these results, FEM procedures are applied to the R/C cooling tower structures assembled by huge R/C shell structure and a lot of discrete R/C columns. In this analysis, the parallel computing procedures are introduced into these analyses to reduce the computational effort. The dynamic performances of R/C cooling tower are also solved by the application of parallel computations as well. From the numerical analyses, the conventional FEM procedures combined with computational technologies enables us to design the huge R/C structures statically and dynamically.

• 한국정보전자통신기술학회논문지
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• 제4권4호
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• pp.278-285
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• 2011

본 논문에서는 DVB-S2 표준안에서 권고되고 있는 irregular LDPC 부호의 다양한 부호화율에서 부호화 방식 및 복호화 방식에 대해 살펴보고 이에 대한 성능분석을 하였다. 또한 이의 구현에 있어서 효율적인 메모리 할당 및 이에 따른 구현 방법에 대해 연구하였다. LDPC 복호기를 구현하는 방안에는 직렬, 부분병렬, 완전병렬 방식이 있으며, 부분병렬방식이 하드웨어 복잡도와 복호속도를 절충하는 방안이다. 따라서 본 논문에서는 부분병렬 구조를 기반으로 하는 LDPC 복호기의 메모리 설계에서 효율적인 체크노드, 비트노드, LLR 메모리의 구조를 제안하고저 한다.