• 한국안전학회지
• /
• 제14권2호
• /
• pp.70-76
• /
• 1999

In this paper, a mixed-integer programming approach is presented for adjusting the voltage profiles in a power system. The advent of large-scaled system makes the reactive power and voltage problem-an attempt to achieve an overall improvement of system security, service quality and economy-more complex and seriously, Although the problem is originally a nonlinear optimization problem, it can be formulated as a mixed integer linear programming(MILP) problem without deteriorating of solution accuracy to a certain extent. The MILP code is developed by the branch and bound process search for the optimal solution. The variable for modeling transformer tap positions is handled as discrete one, and other variables continuous ones. Numerical data resulting from case study using a modified IEEE 30 bus system with outaged line show that the MILP can produce more reductions of magnitude in the operating cost. The convergence characteristics of the results are also presented and discussed.

• 경영과학
• /
• 제27권2호
• /
• pp.55-66
• /
• 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.

• 경영과학
• /
• 제25권1호
• /
• pp.43-53
• /
• 2008

This paper considers a profit-based unit commitment problem with fuel consumption constraint and maintenance cost, which is one of the key decision problems in electricity industry. The nature of non-linearity inherent in the constraints and objective functions makes the problem intractable which have led many researches to focus on Lagrangian based heuristics. To solve the problem more effectively, we propose mixed integer programming based solution algorithm linearizing the complex non-linear constraints and objectives functions. The computational experiments using the real-world operation data taken from a domestic electricity power generator show that the proposed algorithm solves the given problem effectively.

• 경영과학
• /
• 제25권1호
• /
• pp.55-74
• /
• 2008

In recent warfare, the performance improvement of air weapon systems enables an aircraft to strike multiple targets on a single sortie. Further, aircrafts attacking targets may carry out an operation as a strike package that is composed of bombers, escort aircrafts, SEAD (Suppression of Enemy Air Defenses) aircrafts and etc. In this paper, we present an aircraft allocation model that allocates multiple targets to a single sortie in the form of a strike package. A mixed integer programming is developed and solved by using a commercially available software. The new model is better than existing ones because not only it allocates aircrafts to multiple targets but also it models the concept of the strike package. We perform a computational experiment to compare the result of the new model with that of existing ones, and perform sensitivity analysis by varying a couple of important parameters.

• 한국경영과학회:학술대회논문집
• /
• 한국경영과학회/대한산업공학회 2003년도 춘계공동학술대회
• /
• pp.660-667
• /
• 2003

In this study, a Multiple Objective Mixed Integer Programming (MOMIP) Model is developed for sewer rehabilitation planning by considering cost, inflow/infiltration. A sewer rehabilitation planning model is required to decide the economic life of the sewer by considering trade-off between cost and inflow/infiltration. And it is required to find the optimal rehabilitation timing, according to the cost effectiveness of each sewer rehabilitation within the budget. To develop such a model, a multiple objective mixed integer programming model is formulated based on network flow optimization. The network is composed of state nodes and arcs. The state nodes represent the remaining life and the arcs represent the change of the state. The model consider multiple objectives which are cost minimization and minimization of inflow/infiltration. Using the multiple objective optimization, the trade-off between the cost and inflow/infiltration is presented to the planner so that a proper sewer rehabilitation plan can be selected.

• 한국항공우주학회지
• /
• 제47권11호
• /
• pp.787-794
• /
• 2019

본 논문에서는 다수 이종 근접 방어 시스템(Closed-In Weapon System, CIWS)의 최적 무장 할당 문제를 제시하고, 이를 혼합정수선형계획법(Mixed Integer Linear Programming, MILP)으로 변형해 해결하는 기법을 제안한다. 일반적인 무장 할당 문제의 경우 다양한 경우의 수를 고려해야하기 때문에 계산 시간이 기하급수적으로 증가하는 경우가 잦다. 하지만 주어진 문제를 MILP와 같은 혼합정수 최적화 문제로 변형하면 준실시간 내에 전역 최적해를 찾을 수 있다. 본 논문에서는 다수 위협이 각각 다른 시점에 다른 방향에서 방어 자산을 공격하는 상황을 고려한다. 또한, 제원이 다른 다수 CIWS를 동시 운용하는 경우를 추가로 고려한다. 본 논문에서는 이와 같은 문제 상황을 비선형 혼합정수계획 문제로 정식화하고, 이를 MILP로 변형하는 기법을 제시하였다. 또한, 이를 상용 최적화 프로그램으로 구현해 최적화 성능을 검증하였다.

• International Journal of Internet, Broadcasting and Communication
• /
• 제14권4호
• /
• pp.212-221
• /
• 2022

Currently, issues related to freight at Vietnamese logistics companies are becoming more and more urgent because of typical problems in Vietnam such as traffic, infrastructure, and application of information technology. This problem has been studied by applying many different approaches such as Integer Programming (LP), Mixed Integer Programming (MIP), hybrid, meta search, … In this paper, we applied the ILP model in order to deal with the VRP problem in a small size logistics company which is very popular in Vietnam. The experiments showed promising results with some optimal solutions with some small extra costs.

• 한국경영과학회지
• /
• 제10권2호
• /
• pp.24-27
• /
• 1985

This paper presents sufficient conditions for zero duality gap of Lagrangean relaxation in mixed integer programming problems and discusses about an algorithm which updates multipiers using the dual varibles of the linear programming constructed by fixing integer variables.

• 대한산업공학회지
• /
• 제10권2호
• /
• pp.45-50
• /
• 1984

This paper is concerned with the facility location-allocation problem (FLAP) with multiple objectives. A branch-and-bound procedure is presented to solve the mixed zero-one integer goal programming problem which is to determine facility locations from given candidate locations and to allocate facility capacity to given customer markets simultaneously. A numercial example is given to illustrate this procedure.

• 대한수학회지
• /
• 제48권1호
• /
• pp.13-21
• /
• 2011

In this paper, a pair of Wolfe type nondifferentiable sec-ond order symmetric minimax mixed integer dual problems is formu-lated. Symmetric and self-duality theorems are established under $\eta_1$-bonvexity/$\eta_2$-boncavity assumptions. Several known results are obtained as special cases. Examples of such primal and dual problems are also given.