• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.7A
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• pp.776-785
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• 2008

Compared with the existing cellular base station whose radio parameters are configured manually, the small base station named as self-configurable base station configures its radio parameters automatically by the central controller. When installing the self-configurable base station, it should be considered primarily that the seamless coverage for the target area is secured while the signal interference to the existing cellular service area must to be minimized. In order to achieve this, it is very important to select the correct radio parameters, e.g., transmission power and working frequency. In this work, we formulate and solve the optimization problem by using mixed integer programming to optimize the air parameter for the self-configurable base stations.

• Journal of Navigation and Port Research
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• v.28 no.1
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• pp.83-90
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• 2004

Navy surface vessels require pier services such as emergency repair, oil supply, arm loading / unloading, craning, standby readiness, normal repair, gun arrangement, ammunition loading, and food loading during the period in port. The purpose of this study is to establish efficient berth allocation plan for navy surface vessels in home port under the limited resources of piers and equipments. This study suggests Mixed Integer Programming model for berth allocation problem, considering precedence relationships among services. For an effective analysis, the model is implemented by ILOG OPL(Optimization Programming Language) Studio 3.1 and ILOG CPLEX 7.0. The results of the model show reduction of berth shifts and increasement of service benefits.

• Journal of the Korean Geographical Society
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• v.46 no.6
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• pp.724-737
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• 2011

The goal of solving a contiguous land acquisition problem is to find an optimal cluster of land parcels so that one can move from an acquired parcel to another without leaving the cluster. In many urban and regional planning applications, criteria such as acquisition cost and compactness of acquired parcels are important. Recent research has demonstrated that spatial contiguity can be formulated in a mixed integer programming framework. Spatial compactness, however, is typically formulated in an approximate manner using parameters such as external border length or other shape indices of acquired land parcels. This paper first develops an alternative measure of spatial compactness utilizing the characteristics of the internal structure of a contiguous set of land parcels and then incorporates this new measure into a mixed integer program of contiguous land acquisition problems. A set of computational experiments are designed to demonstrate the use of our model in a land acquisition context.

• Korean Chemical Engineering Research
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• v.50 no.3
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• pp.479-491
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• 2012

In this paper we performed evaluation of the economics of a district heating system (DHS) consisting of energy suppliers and consumers, heat generation and storage facilities and power transmission lines in the capital region, as well as identification of optimal operating conditions. The optimization problem is formulated as a mixed integer linear programming (MILP) problem where the objective is to minimize the overall operating cost of DHS while satisfying heat demand during 1 week and operating limits on DHS facilities. This paper also propose a new forecasting model of the system marginal price (SMP) using past data on power supply and demand as well as past cost data. In the optimization, both the forecasted SMP and actual SMP are used and the results are analyzed. The salient feature of the proposed approach is that it exhibits excellent predicting performance to give improved energy efficiency in the integrated DHS.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.04a
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• pp.519-524
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• 1996

This paper describes the application of Genetic Algorithms(GAs) to nonlinear constrained mixed optimization problems. Genetic Algorithms are combinatorial in nature, and therefore are computationally suitable for treating discrete and integer design variables. But, several problems that conventional GAs are ill defined are applicaiton of penalty function that can be adapted to transform a constrained optimization problem into an unconstrained optimization problem into an unconstrained one and premature convergence of solution. Thus, we developed an modified GAs to solve this problems, and two examples are given to demonstrate the effectiveness of the methodology developed in this paper.

• Korean Management Science Review
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• v.32 no.4
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• pp.109-133
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• 2015

This paper considers the allocation and engagement scheduling of air defense missiles by using MIP (mixed integer programming). Specifically, it focuses on developing a realistic MIP model for a real battle situation where multiple enemy missiles are headed toward valuable defended assets and there exist multiple air defense missiles to counteract the threats. In addition to the conventional objective such as the minimization of surviving target value, the maximization of total intercept altitude is introduced as a new objective. The intercept altitude of incoming missiles is important in order to minimize damages from debris of the intercepted missiles and moreover it can be critical if the enemy warhead contains an atomic or chemical bomb. The concept of so called the time window is used to model the engagement situation and a continuous time is assumed for flying times of the both missiles. Lastly, the model is extended to simulate the situation where the guidance radar, which guides a defense missile to its target, has the maximum guidance capacity. The initial mathematical model developed contains several non-linear constraints and a non-linear objective function. Hence, the linearization of those terms is performed before it is solved by a commercially available software. Then to thoroughly examine the MIP model, the model is empirically evaluated with several test problems. Specifically, the models with different objective functions are compared and several battle scenarios are generated to evaluate performance of the models including the extended one. The results indicate that the new model consistently presents better and more realistic results than the compared models.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2007.04a
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• pp.305-308
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• 2007

In this paper we suggest an efficient evolutionary approach based on topological sort techniques for precedence constrained TSPs. The determination of optimal sequence has much to offer to downstream project management and opens up new opportunities for supply chains and logistics. Experimental results show that the suggested approach is a good alternative to locate optimal solution for complicated precedence constrained sequencing as in optimization method for instance.

• Journal of Korean Institute of Industrial Engineers
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• v.10 no.1
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• pp.3-10
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• 1984

A materials acquisition planning (MAP) problem that involves the determination of how much to order of a number of different items from a number of different suppliers is considered. This particular problem is modelled as a nonlinear mixed integer programming problem. A solution procedure based upon the partition of variables is developed to handle the MAP problem. This solution procedure utilizes a modified Hooke-Jeeves Pattern Search procedure along with a linear programming simplex algorithm. An example problem is presented and the results of applying the suggested solution procedure to this problem are reported.

• Journal of Korean Society of Transportation
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• v.10 no.3
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• pp.75-102
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• 1992

지난 수십년간 수많은 신호교차로제어모형이 제시되어 왔으나 과포화교차로를 특별히 다루는 기법은 거의 없었다. 본고에서는 과포화상태의 신호교차로제어를 위한 최적화모형이 제시된다. 지체도최소화나 연동폭최대화가 전통적인 제어목표로 사용되어 왔으나 혼잡교차로 제어에는 생산성최대화(maximum productivity)가 적절하며 본 모형에 사용되었다. 제시된 최적화모형은 Mixed Integer Linear Programming의 형태를 취한다. 본 모형은 두 개의 교차로 문제에 적용되었으며, 모형화 과정에 사용된 가정들의 적절함이 민감도분석에 의해 증명되었다. 최적해의 검증을 위하여 microscopic simulation model인 TRAF-NETSIM을 사용하였다.

• Journal of the Korean Operations Research and Management Science Society
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• v.39 no.2
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• pp.37-48
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• 2014

Fighter squadron flight scheduling is the integrated air operation plan that is an important role for improving pilot's flight skill and maintaining combat readiness by efficient using available all air resources including pilot, aircrafts, air-weapons, fuel and supporting facilities etc. Korea airforce, however, has a limit as to an effective flight operation due to manual flight scheduling with scheduler's own experience and intuition. Therefore, in our study, we propose the optimization model of flight scheduling based on mixed integer programming. This model includes several constraints of realistic and essential quantified data related with flight schedule and can assign appropriate pilots optimally which are distinctive three type's solutions : flight, alert and duty crew schedules. Proposed solution method can be improved pilot's capability and allocated further air resources systematically and efficiently. In addition, it can be reduced a workload of flight scheduler and minimized obstructed factors of flight safety. Finally, we demonstrate the experiment's results for the check of efficiency and validity of this model.