• Computational Structural Engineering
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• v.10 no.2
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• pp.255-263
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• 1997

The optimum design of most structural systems used in practice requires considering design variables as discrete quantities. The present paper shows that the linear approximation method is very effective as a tool for the discrete optimum designs of unsymmetric composite laminates. The formulated design problem is subjected to a multiple in-plane loading condition due to shear and axial forces, bending and twisting moments, which is controlled by maximum strain criterion for each of the plys of a composite laminate. As an initial approach, the process of continuous variable optimization by FDM is required only once in operating discrete optimization. The nonlinear discrete optimization problem that has the discrete and continuous variables is transformed into the mixed integer programming problem by SLDP. In numerical examples, the discrete optimum solutions for the unsymmetric composite laminates consisted of six plys according to rotated stacking sequence were found, and then compared the results with the nonlinear branch and bound method to verify the efficiency of present method.

• Journal of Korean Society of Transportation
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• v.19 no.3
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• pp.75-88
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• 2001

Signal optimization model for alternative use of lanes at a signalized intersection with an stop-line added backward was presented in this paper. The simulation results shot-ed that the traffic fed from the stop-line passed the intersection in each specified phasing interval for left and through traffic. The experimental results indicated that the proposed model was much superior to traditional signal optimization methodology in reducing delay, fuel consumption, and disutility index for delay and stops. The effects for reducing delay were greater than those for doing fuel consumption and disutility index due to the added stop-line. The proposed model is expected to alleviate traffic congestion at intersections, both which have no left turn pocket, and which have large left turn volume. The model is recommended to adapted for intersections spaced long among them with no near driveway.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.479-482
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• 2011

This paper proposes a design of a ship backbone network-based on the survival and efficiency of the ship network. Currently IEC operates the standard ship network, a standard specification "IEC 61162-410 maintains the operation of the network. IEC 61162-410 offers a high stability of the ship network by using terminal equipment. But current studies are incomplete because it has been assumed that the ship's network will operate at double its current capacity. This paper analyzes the double ship backbone topology for an organization and then will summarise the minimum costs required to implement the ship backbone topology using an ILP. Also, we present an effective traffic assignment technique that uses an ILP, metaheuristic, heuristic algorism-based underlying the ship backbone network. The results by experimenting the design of the network confirmed a greter efficiency, stability and cost-effectiveness of the ship network.

• Proceedings of the Korea Association of Information Systems Conference
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• 1997.10a
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• pp.53-73
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• 1997

대부분의 조직들은 그 조직의 생존과 발전을 위해 장기 전략 계획과 동시에 운영 을 위한 구체적 단기 계획(예 : 생산 계획)을 항상 수립 또는 조정하고 있다. 특히 장기적인 관점에서의 이익 극대화와 생존을 위해 수립되거나 조정된 장기 전략 계획을 효과적으로 달 성하기 위해서는 실제 그 전략을 수행하기 위한 단기 계획에 대한 전략 계획 결과의 일관되 고 지속적인 반영이 필수적이다. 그러나 단기 계획 수립 시점에서 전략 목표나 전략 계획의 내용을 단기적으로 실현 가능한 이익 관점에서 양적으로 구체화하여 평가하기 어려운 현실 적 이유로 인해 대부분의 경우 객관적으로 측정 가능한 단기 이익을 극대화하는 방향으로 단기 계획을 수립하는 것이 보통이다. 따라서 이러한 단기 계획의 수립은 장기 전략 계획과 의 불일치를 가져오게 되며 궁극적으로 기업의 장기적 이익 극대화와 생존에 불리한 결과를 초래할 수도 있다. 이에 따라 본 연구에서는 장기전략 계획이 구체적인 단기 계획에 있어 어떤 구체적이고 명시적인 의미나 결과를 가지게 되는지를 파악할 수 있는 체계를 모형화 하고, 이를 바탕으로 장기 전략 계획을 달성하기 위해 혹은 장기 전략 계획의 변화가 발생 했을 경우 이에 따른 단기 계획에의 일관된 조정을 수행할 수 있는 방법론을 개발 제시하고 자 한다. 본 연구에서는 이를 위해 장기 전략 계획으로는 포트폴리오(Portfolio) 계획 모형을 가정하고 있으며, 단기 계획 수립은 최적화 모형(예 : 선형계획법)을 사용하는 것을 전제로 하여 신경망 기반 응용최적통제(Adaptive Optimal Control)기법을 통해 포트폴리오 모형을 전략 목표를 위한 최적화 모형의 통제 및 조정을 수행함으로써 전략 계획에 의한 단기 계획 조정을 달성하고자 한다. 본 연구에서 제시한 방법론은 장기 전략 목포를 달성하기 위한 일 관적인 기군에 따른 적절한 단기 계획의 통제가 가능하다는 것을 보여주었으며 나아가서 장 기 전략 목표와 단기 이익간의 체계적인 상호 교환적 절충의 가능성 역시 경험적으로 증명 하고 있다. 이는 대부분의 기업 환경에 적용되어 현대의 빠른 기업 환경 변화에 대응하기 위한 전략 계획의 변화를 신속하고 효과적으로 단기 계획에 반영할 수 잇는 방법을 제시함 으로써 기업의 전략 목표 달성에 중요한 역할을 담당할 수 있을 것으로 기대한다.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.89-93
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• 2009

홍수기에 집중되는 하천유출량을 갈수기에 적절히 활용하기 위한 대표적인 시설이 댐이다. 제한된 용수공급량을 적절히 분배해 용수수요량을 만족시키면서 미래 갈수기시 용수공급을 위한 댐 저류량을 조절하는 것이 댐 운영의 중요한 목적 중 하나이다. 본 연구에서는 댐 저류량에 따라 댐 계획방류량을 일정비율 줄여주는 Hedging Rule을 5단계로 적용하여 댐의 상시만수위 저류량에 대한 실제 저류량의 편차 절대치 합, 수요에 대한 용수공급 부족량의 합, 그리고 하천유지유량에 대한 하천유량 부족량의 합을 목적함수로 하여 혼합정수 선형계획법(MILP, Mixed Integer Linear Programming)으로 식을 구성하였다. 한강수계의 다목적댐인 충주, 횡성, 소양강 댐과 용수전용댐인 광동 댐, 그리고 발전용 댐이지만 비교적 큰 저류용량을 가진 화천 댐을 댐 연계 운영 대상으로 하여 수자원장기종합계획의 2003년 유출량 및 수요량 자료와 댐운영실무편람의 댐 계획방류량 자료를 10일 단위로 입력하여 GAMS/CPLEX를 이용해 최적화하였다. 그 결과 생공용수 수요량 99.99%, 농업용수 수요량 99.91%, 그리고 하천유지용수 수요량 99.24%를 충족시키면서, 댐 저류율이 66.54%에서 86.39%로 증가하였다.

• Journal of Korea Society of Industrial Information Systems
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• v.15 no.5
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• pp.187-196
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• 2010

We present a link that allows Excel to call the functions in the lp_solve system. lp_solve is free software licensed under the GPL that solves linear and mixed integer linear programs of moderate size. Our link manages the interface between Excel and lp_solve. Excel has a built-in add-in named Solver that is capable of solving mixed integer programs, but only with fewer than 200 variables. This link allows Excel users to handle substantially larger problems at no extra cost. Futhermore, we introduce that a network drawing method in Excel using arc adjacency lists of a network.

• Journal of the Korean Society of Marine Environment & Safety
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• v.17 no.4
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• pp.323-329
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• 2011

This study is to determine an optimal yacht mooring location candidate among many alternative candidates in order to obtain the maximized efficiency under the natural conditions using integer programming. To deal with marina's construction location, the optimal construction location is selected using 21 important factors analysis for 4 candidates in the Mokpo city. The development period and the initial investment cost weight are one and half times more than the others among 21 factors. The optimal spiral analysis of weighted linear model shows that the Peace Square sea area is selected as the most optimal place among 4 candidates. This proposed model has not been applied in the optimal marina's facility candidate selection problem yet. This paper will contribute to determine the most reasonable alternative. Also, this proposal model can be applied to other marina's facility candidate selection problem in other regions.

• Journal of Korean Society of Transportation
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• v.22 no.7 s.78
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• pp.161-167
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• 2004

While most or fixed-time control systems such as UTCS produce the signal timing plans that either maximizing bandwidth or minimizing a disutility index of delay and stops, cannot consider the fluctuation of traffic flow. One category of the traffic-response control systems, which make small changes on a predefined signal plan such as SCOOT, cannot be easily modified for feedback real-time control schemes based on observation of variables other than traffic flow. The other category, which decide to whether switch the traffic lights or not at each step of time as in PRODYN, does not adequately consider the relations between traffic flows and traffic lights at each step of time. In this paper we present a complete formulation that adequately consider the relations between traffic flows and traffic lights at each step of time. The formulation is a binary mixed integer linear programing (BMILP) that obtain traffic lights at each step for minimizing delay. Since numarical examples for application of the proposed model illustrated that the model adequately produced dynamic traffic signal plans minimizing delay at each step, the model may be expected to contribute to advanced transportation management systems (ATMS) for dynamic traffic signal control.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.7
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• pp.1416-1427
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• 2012

This paper proposes a design technique of a survivable ship backbone network, which describes a near optimal configuration scheme of physical and logical topologies of which the survivable ship backbone network consists. We first analyze and present an efficient architecture of a survivable ship backbone network consisting of redundant links and ship devices with dual communication interfaces. Then, we present an integer linear programming-based configuration scheme of a physical topology with regard to the proposed ship backbone network architecture. Finally, we present a metaheuristic-based configuration scheme of a logical topology, underlying the physical topology.

• The Journal of Fisheries Business Administration
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• v.46 no.3
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• pp.73-82
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• 2015

This study aimed to evaluate the effectiveness of closed season policy using an integer linear programming, targeting the large purse seine fishery in Korea. In the analysis, based on Cheng and Townsend(1993), fishing effort (fishing days by month) was assumed to be distributed for profit maximization of vessels and catch of immature fish was estimated. The analytical results showed that the effects of closed season policy would vary in accordance with the monthly closures in terms of fishing profits and catch of immature fish. A closed season policy by month had different effects on fishing profits and catch of immature fish by species. It implies the importance of considering seasonal changes of fish species when limiting fishing efforts with the closed season policy.