• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.5
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• pp.13-22
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• 2018

In this study, a governing differential equation for the bending problem of orthotropic rectangular plate is drived. It's exact solution for various boundary conditions is presented. This solution follows traditional method like Navier's solution or Levy's solution that transforms the governing differential equation into an algebraic equation by using trigonometric series. To obtain a solution by Levy's method, it is required that two opposite edges of the plate be simply supported. And the boundary conditions, for which the Navier's method is applicable, are simply supported edge at all edges. In this study, it overcomes the limitations of the previous Navier's and Levy's methods.This solution is applicable for any combination of boundary conditions with simply supported edge and clamped edge in x, y direction. The plate could be subjected to uniform, partially uniform, and line loads. The advantage of the solution is that it is the exact solution as well as it overcomes the limitations of the previous Navier's and Levy's methods. Calculations are presented for orthotropic plates with nonsymmetric boundary conditions. Comparisons between the result of this paper and the result of Navier, Levy and Szilard solutions are made for the isotropic plates. The deflections were in excellent agreement.

• 한국방재학회:학술대회논문집
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• 2009.02b
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• pp.152.1-152.1
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• 2009

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1992.04b
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• pp.14-23
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• 1992

본 논문은 스케줄링 문제등 정수계획문제에서 흔히 찾아볼 수 있는 변수상한 제약을 갖는 문제의 효율적인 해법을 위한 분석적인 틀을 마련하기 위한 연구이다. 본 연구에서는 이 문제에 관한 기존의 알고리즘적 해법과 달리 분해기법을 이용하여 일반변수상한 문제에 까지 확장 적용될 수 있음을 분석적으로 보였다.

• Satellite Communications and Space Industry
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• v.9 no.3 s.23
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• pp.48-57
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• 2001

지난 10월 일본 교토에서 개최되었던 2001 한일 위성통신 컨퍼런스를 통해 나타난 위성분야의 최신 기술동향과 앞으로의 발전방향에 대해 논의함과 아울러 국내 위성통신분야 기술과 산업발전을 위한 현안과제의 해법을 알아보고자 디지털타임스가 마련한 특별좌담회를 개최하였다. 우리나라 최고의 석학분들로부터 듣는 명쾌한 해법안 내용 전량을 회원여러분들에게 지상을 통해 소개한다

• Tunnel and Underground Space
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• v.10 no.3
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• pp.257-270
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• 2000

사물의 거동, 현상에 대한 해석을 실시함에 있어 해석적 해법에 대비한 수치적 해법의 장점은 재질의 성질이 불균질하고 이방성이며 구조물의 형태가 기하학적으로 복잡할 뿐만 아니라 경계조건이 복잡하여 수학적인 표현이 어려울 때 그 해석을 가능케 해 주는 것이라고 볼 수 있다. 이러한 수치 해석법의 대표적인 것으로 유한요소법과 경계 요소법을 들 수 있다.(중략)

• Computational Structural Engineering
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• v.9 no.3
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• pp.47-53
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• 1996

공학 전반에 걸쳐 다양한 형식으로 개발되어 사용되고 있는 병렬계산법의 기본개념과 병렬계산기의 분류에 대하여 소개하였으며, 구조해석시 가장 많은 시간을 요하는 방정식해법을 preconditioned conjugate gradient를 이용하여 병렬화하는 과정과 병렬알고리즘을 소개하였다. 그리고 소개된 병렬방정식해법을 대형구조물의 해석 및 설계에 적용하여 병렬계산의 효율성을 speedup을 이용하여 도표화하였다.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06a
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• pp.154-157
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• 2011

본 연구는 2인의 전문의와 함께 의료 문헌의 초록을 분석하여 의료문서에서의 절차적 지식을 모델링하고 텍스트 마이닝 기법을 적용하여 절차적 지식을 추출하는 방법론에 대해 기술한다. 절차적 지식은 목적과 해법의 묶음으로, 해법은 다시 단위 절차 지식의 네트워크로 정의 하였고, 목적과 해법 정보 추출과 단위 절차 지식의 구성요소인 대상/행위/방법 개체를 인식하기 위해, 품사태깅, 구문분석, 술어-논항구조(Predicate-Argument Structure), 온톨로지 용어 매핑 정보 등에 기반한 기계학습 방법을 사용하였다. 실험을 위해 전문의와 함께 위함과 척추질환에 대한 1309 문서에 절차적 지식 태깅을 수행하였고, 이 문서 집합을 기반으로 목적/해법 추출 작업과 단위 절차 지식(대상질병/행위/적용방법) 추출 실험을 수행하여, 각각 82% 와 63%의 F-measure 값을 얻을 수 있었다.

• Journal of the Korean Society for Railway
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• v.12 no.6
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• pp.1018-1023
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• 2009

This paper describes a reduction in the peaks of traction energy for metro railways in timetabling. We develope a mixed integer programming (MIP) model, which minimizes the number of trains running simultaneously. We suggest two approaches. In the first approach, we use the commercial MIP solver, CPLEX. In the second approach, we propose a heuristic algorithm. We apply both methods to the current daily timetable of the Korea Metropolitan Subway. We determine an optimal solution, which results in an improvement of approximately 25% over the current timetable.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.12 no.6
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• pp.545-553
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• 1987

An approximation algorithm has been obtained to analyze the network of single server tandem queues with a finite length. In the queueing network with a finite queue length, the blocking which is mutually dependent, occure due to the limitation of the queue length. Thus, it is difficults to analyze such a queueing network. In this paper each queue has been regarded as the independent M/M/1/K system to analyze the queueing network with the blocking, which is based on the assumption that an arrival rate to the present station is increased by the blocking of the following stations. The performance measures, such as state probability, average queue length and tha waiting time, can be easily obtained using the proposed algorithm. In order to justify this approximation algorithm, comparison of the results of this algorithm with those of state transition simultaneous equations has been made an verified with computer simulation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.9A
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• pp.1452-1460
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• 2000

A series of papers in recent literature on logical topology design for wavelength routed optical networks have proposed mathematical models and solution methods unifying logical topology design wavelength assignment and traffic routing. The most recent one is by Krishnaswamy and Sivarajan which is more unifying and complete than the previous models. Especially the mathematical formulation is an integer linear program and hence regarded in readiness for an efficient solution method compared to the previous nonlinear programming models. The solution method in [7] is however elementary one relying on the rounding of linear program relaxation. When the rounding happens to be successful it tends to produce near-optimal solutions. In general there is no such guarantee so that the obtained solution may not satisfy the essential constraints such as logical -path hop-count and even wavelength number constraints. Also the computational efforts for linear program relaxation seems to be too excessive. In this paper we propose an improved and unifying solution method based on the same to be too excessive. In this paper we propose an improved and unifying solution method based on the same model. First its computation is considerably smaller. Second it guarantees the solution satisfies all the constraints. Finally applied the same instances the quality of solution is fairly competitive to the previous near optimal solution.