• 대한수학회지
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• 제37권6호
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• pp.1021-1030
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• 2000

We formulate a pair of symmetric dual mixed integer programs with a square root term and establish the weak, strong and converse duality theorems under suitable invexity conditions. Moreover, the self duality theorem for our pair is obtained by assuming the kernel function to be skew symmetric.

• Journal of applied mathematics & informatics
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• 제19권1_2호
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• pp.371-384
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• 2005

Usual symmetric duality results are proved for Wolfe and Mond-Weir type nondifferentiable nonlinear symmetric dual programs under F-convexity F-concavity and F-pseudoconvexity F-pseudoconcavity assumptions. These duality results are then used to formulate Wolfe and Mond-Weir type nondifferentiable minimax mixed integer dual programs and symmetric duality theorems are established. Moreover, nondifferentiable fractional symmetric dual programs are studied by using the above programs.

• 경영과학
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• 제27권2호
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• pp.55-66
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• 2010

In Korea, deap-sea fishing industry plays an important role in a food industry. However, it is in a difficult situation because of the more competitive business environment. Therefore, there is a need to restructure the deap-sea fishing industry by scraping superannuated ships. This paper is designed to present scrap programs for deap-sea fishing industry of Korea. We performed ratio analysis to evaluate financial performance of fishing companies and then applied a mixed integer programming (MIP) model to identify optimal schedule for scraping. The results of the financial ratio analysis indicates that it is legible to provide governmental aid to Atlantic trawl, Northern Pacific trawl, and Indian ocean trawl with minimum required rate of return (MRR) of 3%, and the Atlantic strip fishing industry is qualified to receive the governmental aid with MRR value of 5%. Furthermore, by applying the MIP model to develop scrap planning, we demonstrate how our model can be used to restructure the deap-sea fishing industry of Korea.

• 한국산업정보학회논문지
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• 제15권5호
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• pp.187-196
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• 2010

네트워크 최적화 문제는 의사결정 문제 중에서 노드와 아크로 표현되는 수 많은 문제를 포함하고 있어서, 그 응용범위가 매우 다양할 뿐만 아니라 매우 실질적인 문제를 해결하는 좋은 방법론이다. 직접적으로 관련이 없는 많은 최적화 문제들도 네트워크로 적절히 표현할 수 있는 경우가 많으며 이를 통해 보다 섬도 있는 문제에 대한 이해와 해의 도출이 가능하게 된다. 이처럼 광범위한 응용분야를 가지는 네트워크 최적화 문제는 경영과학 및 산업공학에서 기본이 중요 학문이며, 이를 체계적으로 이해하고 실제 문제를 해결하려면 최적화 이론, 계산이론, 프로그래밍 등의 종합적인 지식을 필요로 한다. 본 연구에서는 네트워크 최적화 문제를 실질적으로 해결하는 필요한 지식 전달에 중점을 두고, 선형계획법 및 정수계획법을 위한 소프트웨어인 LPSolve를 소개하고 이 LPSolve와 엑셀을 연동하는 방법을 알아본다. 또한 네트워크 자체를 엑셀에서 그리는 방법을 알아보고, 이를 통해 네트워크 최적화 문제를 보다 실질적인 다룰 수 있도록 한다.

• 전기학회논문지
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• 제56권2호
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• pp.260-267
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• 2007

Systematic studies on the dispatch scheduling algorithm can enhance the efficiency of electricity market operation. In addition, as the dispatching policies in competitive electricity markets directly affect the market participants' profits, the dispatch scheduling procedure should be reasonable, systematic, and transparent. In this paper, we propose an unconstrained/constrained pre-dispatch scheduling algorithm and develop corresponding programs applicable to wholesale electricity markets.

• 경영과학
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• 제20권1호
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• pp.65-76
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• 2003

The increased environmental concerns and the emphasis on recycling are gradually shifting the orientation of municipal solid waste (MSW) management. This paper is designed to evaluate regionalization programs for MSW management system. We developed a mixed intiger network programming (MIP) model to identify environment-friendly, cost-effective expansion plans for regionalization scenarios considered. The MIP model is a dynamic capacity expansion model based on the network flow model that depicts the MSW management cycle. In particular, our model is designed to determine the optimal form of regionalization using binary variables. We apply this model to assess the regionalization program of Seoul Metropolitan City, which includes three scenarios such as 1) districting, 2) regionalization with neighboring self-governing districts, and 3) g1obalization with all districts. We demonstrate how our model can be used to plan the MSW system. The results indicate that optimal regionalization with nearby self-governing districts can eliminate unnecessary landfills and expansions if jurisdictional obstacles are removed.

• Asian Journal of Innovation and Policy
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• 제8권1호
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• pp.122-140
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• 2019

Providing free primary care to everyone is an important goal pursued by many countries under universal health care programs. Countries like India need to efficiently utilize their limited capacities towards this purpose. Unfortunately, due to a variety of reasons, patients incur substantial travel and out-of-pocket expenses for getting primary care from publicly-funded facilities. We propose a set-covering optimization model to assist health policy-makers in managing existing capacity in a better way. Decision-making should consider upgrading centers with better potential to reduce patient expenses and reallocating capacities from less preferred facilities. A multinomial logit choice model is used to predict the preferences. In this article, a brief background and literature survey along with the mixed integer linear programming (MILP) optimization model are presented. The working of the model is illustrated with the help of numerical experiments.

• 한국산학기술학회논문지
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• 제11권9호
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• pp.3304-3310
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• 2010

연구는 가격 및 수요 불확실성하의 강건한 (robust) 생산 및 수송 전략을 수립함으로써 수요 및 가격 불확실성이 존재하는 TFT-LCD 제조업 공급사슬망의 의사결정 문제를 해결하고자 한다. 품질로 구분되는 제품들의 생산, 재고 및 물류에 관한 의사결정을 조정하기 위해, 본 연구에서는 생산용량 제약, 해상/항공 수송 리드타임 및 용량 제약 등의 현실적인 제약조건들을 반영하는 확정적 모델을 정의하고, 시나리오 모델을 이용하여 수요 및 가격 불확실성을 함께 반영하는 확률적 혼합정수선형계획법모형들을 개발한다. 또한 개발된 확률적 모형들의 robust 솔루션을 도출하기 위한 휴리스틱 알고리즘을 제안한다. 그리고 이들 모형들로부터 산출된 솔루션의 성능을 실험을 통하여 다양한 시나리오 하에서 평가하도록 한다.