• 한국컴퓨터산업학회논문지
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• 제5권7호
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• pp.711-720
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• 2004

프로그램을 계산적으로나 수명적으로 최적화하는 기법에는 수식 모션 변환과 수식 모션을 포함하는 배정문 모션 변환이 있다. 본 논문에서는 노드 단위 분석과 명령어 단위 분석의 혼용 때문에 발생하는 모호함을 가지는 Knoop의 알고리즘을 개선하는 불필요한 코드 모션 재구성 알고리즘을 제안하였다. 제안한 알고리즘은 수식이나 배정문의 불필요한 재계산이나 재수행을 피하게 함으로써 프로그램의 능률과 수행시간을 개선하였다.

• 전자공학회논문지A
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• 제28A권10호
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• pp.847-854
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• 1991

This paper presents a new output phase assignment algorithm which determines the phases of all the nodes in a given boolean network. An estimation function is defined, which is represented by the relation between the literals in the given function expression. A weight function, WT (fi, fj) is defined, which is represented by approximate amount of common subexpression between function fi and fj. Common Subexpression Graph(CSG) is generated for phase selection by the weight function between all given functions. We propose a heuristic algorithm finding subgraph of which sum of weights has maximum by assigning phases into the given functions. The experiments with MCNC benchmarks show the efficiency of the proposed method.

• 한국정밀공학회지
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• 제17권7호
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• pp.162-169
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• 2000

In this paper, we develop a parallel inverted pendulum system that has the characteristics of the strongly coupled dynamics of motion by an elastic spring, the time-variant system parameters, and inherent instability, and so on. Hence, it is possible to approximate some kinds of a physical system into this representative system and to apply the various control theories to this system in order to verie their fidelity and efficiency. For this purpose, an experimental system of the parallel inverted pendulum has been implemented, and a control scheme using the eigenstructure assignment for decoupling control is presented in comparison with the conventional LQR optimal control method. Furthermore, this system can be utilized as a testbed to develop and evaluate new control algorithms through various setups. Finally, in this paper, the results of the experiment are compared with those of numerical simulations for validation.

• 한국산업정보학회:학술대회논문집
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• 한국산업정보학회 1997년도 추계학술대회 발표논문집:21세기를 향한 정보통신 기술의 전망
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• pp.535-552
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• 1997

The facility layout problem has the goal of locating the different facilities in a floor to achieve the greatest efficiency in producing a product or service. This problem is usually formulated as the quadratic assignment problem(QAP). However, the problem of finding optimal layout is hard and traditional approaches are not computationally feasible. In this paper, a genetic algorithm is presented for obtaining efficient layouts. To test the effectiveness of the algorithm, a set of examples is solved and the results are compared to those from other Known algorithms. The comparison indicates that the proposed method performs well for the classical test problems.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1988년도 전기.전자공학 학술대회 논문집
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• pp.913-916
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• 1988

Indirect adaptive pole assignment PID controllers for unknown systems with time varying delay, is proposed. Unknown system parameters are estimated by recursive least square method, and time varying delay is estimated using indirect predictors. Since the order of parameter vectors didn't increase, the computational burden is not largely increased in spite of using indirect adaptive control method with time varying delay estimation. Computer simulation is performed to illustrate the efficiency of the proposed method.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 2002년도 춘계공동학술대회
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• pp.390-396
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• 2002

This study is concerned with the strict machine-cell and part-family grouping (MCPFG) in cellular manufacturing system design. Most of MCPFG methodologies often suffer from improper assignment of machines and parts in which exceptional machine has more common operations with machines in a cell other than its own cell and exceptional part has more operations through machines in a cell other than the cell corresponding to its own family. This results in the loss of similarity in part design or common setup of machines and the benefits from the conversion of job shop manufacturing into cellular manufacturing are lost. In this study, a two-phase methodology is proposed to find the machine-cells and part families under the strict constraints in which all machines and parts are assigned to its most proper cells and families. Test results with moderately medium-sized ill-structured MCPFG problems available from the literature show the substantial efficiency of the proposed approach.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 2003년도 춘계학술대회논문집
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• pp.155-160
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• 2003

Today, for improvement of container terminal productivity, it is necessary to develop ACT(Automated Container Terminal) But, decision rules for conventional container terminals expose various limitations to be applied to ACT. Specially it is important fact to assignment of containers, because the character of ACT which block layout is vertical for berth. And then there is need which assignment of containers with remarshaling work using ATC(Automated Transfer Crane)s. The objective of this study is to provide the operation rules for remarshaling work in ACT. To analyze the proposed rules, the simulation is performed, and we show efficiency of remarshaling on various remarshaling operation rules.

• Journal of Communications and Networks
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• 제18권4호
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• pp.551-558
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• 2016

In multifiber all-optical networks, optical amplifiers are used for amplifying multiple optical signals with different wavelengths in fibers. An optical amplifier operates when any of lightpaths passes through it. Therefore, it should simultaneously amplify as many lightpaths as possible for efficiently utilizing its power. This paper proposes a dynamic lightpath establishment scheme considering the use efficiency of the optical amplifiers and the depletion of the wavelength resources in multifiber all-optical networks. The proposed scheme provides a routing and wavelength assignment strategy that reduces both the power consumption of the optical amplifiers and the blocking probability of the lightpath establishment. Through simulation experiments, we demonstrate the effectiveness of the proposed scheme.

• 한국항공우주학회지
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• 제38권5호
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• pp.427-436
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• 2010

본 논문은 다수의 목표물과 다수의 임무가 존재하는 상황에서의 다수 무인항공기의 임무할당 문제를 다룬다. 다수 무인항공기의 임무할당 문제는 순회 세일즈맨 문제, 차량 라우팅 문제와 같은 조합최적화 문제의 일종으로 NP-hard의 계산 복잡도를 가지고 있다. 이런 성격의 문제는 문제의 크기가 커질수록 계산시간이 급격히 증가하는 특징을 지니기 때문에 문제를 효율적으로 풀기 위해서 근사화 방법 또는 발견적인 방법을 사용한다. 본 연구에서는 임무할당 문제를 혼합정수 선형계획 문제로 정식화하고, 혼합정수 선형계획법과 유전 알고리듬으로 해를 구하였다. 다수의 목표물, 다수의 임무, 장애물이 존재하는 환경에 대한 수치 시뮬레이션을 수행하여 각 방법의 최적성과 효율성에 대해 검토하였다.

• 한국인터넷방송통신학회논문지
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• 제13권5호
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• pp.239-247
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• 2013

다중-인터페이스 기반 네트워크에서 각 노드에 장착된 다수의 무선 인터페이스들을 효율적으로 활용하기 위해서는 각 인터페이스에 이용 가능한 채널들을 적절하게 할당하여 간섭을 감소시키고 대역폭 효율을 높이는 채널 할당 기법이 필요하다. 혼합 할당 방식을 사용하여 네트워크 용량과 처리량을 개선하는 MCS 프로토콜이 제안되었다. MCS는 경쟁 영역 내에서 동일한 채널을 사용하는 노드들의 수를 고정 인터페이스의 채널을 할당하기 위한 기준으로 사용한다. 그러나 이 정보는 실질적으로 채널에 부과되는 부하를 정확히 반영할 수 없는 문제점이 있다. 본 논문에서는 간섭 영역 내에서 동일한 채널을 사용하는 노드들의 수뿐만 아니라 노드들에 의해서 채널이 점유되어 있는 비율을 나타내는 채널 혼잡도를 채널의 부하를 평가하기 위한 기준으로 사용하여 채널을 할당하는 CAMCS 프로토콜을 제안하고 시뮬레이션을 통해서 성능 개선 효과를 확인한다.