• 한국지능시스템학회:학술대회논문집
• /
• 한국퍼지및지능시스템학회 2003년도 ISIS 2003
• /
• pp.380-383
• /
• 2003

In this paper, we propose a fuzzy group decision making method for multiple decision maker-multiple objective programming problems to obtain the agreeable solution. In the proposed method, considering the vague nature of human subjective judgement it is assumed that each of multiple decision makers has a fuzzy goal for each of his/her own objective functions. After eliciting the membership functions from the decision makers for their fuzzy goals, total M-Pareto optimal solution concept is defined in membership spaces in order to deal with multiple decision maker-multiple objective programming problems. For generating a candidate of the agreeable solution which is total M-Pareto optimal, the extended weighted minimax problem is formulated and solved for some weighting vector which is specified by the decision makers in their subjective manner, Given the total M-Pareto optimal solution, each of the derision makers must either be satisfied with the current values of the membership functions, or update his/her weighting vector, However, in general, it seems to be very difficult to find the agreeable solution with which all of the decision makers are satisfied perfectly because of the conflicts between their membership functions. In the proposed method, each of the decision makers is requested to estimate the degree of satisfaction for the candidate of the agreeable solution. Using the estimated values or satisfaction of each of the decision makers, the core concept is desnfied, which is a set of undominated candidates. The interactive algorithm is developed to obtain the agreeable solution which satisfies core conditions.

• 대한산업공학회지
• /
• 제28권1호
• /
• pp.99-104
• /
• 2002

This paper presents a method of sensitivity analysis for the infeasible interior point method when a new variable is introduced. For the sensitivity analysis in introducing a new variable, we present a method to find an optimal solution to the modified problem. If dual feasibility is satisfied, the optimal solution to the modified problem is the same as that of the original problem. If dual feasibility is not satisfied, we first check whether the optimal solution to the modified problem can be easily obtained by moving only dual solution to the original problem. If it is possible, the optimal solution to the modified problem is obtained by simple modification of the optimal solution to the original problem. Otherwise, a method to set an initial solution for the infeasible interior point method is presented to reduce the number of iterations required. The experimental results are presented to demonstrate that the proposed method works better.

• 한국대기환경학회지
• /
• 제12권3호
• /
• pp.315-322
• /
• 1996

Recently, hospital acquired infections have an increase interest as a public problems, which are caused of indoor pollutants in hospital. Microorganisms, ethylene oxide, formaldehyde, and anesthetic gases are main hazardous pollutants in hospital. The possible pathways of the infection are a respiratory channel as well as a blood channel. The blood channel is concerned since these pollutants might be dissolved into the Ringer's solution. The objective of this research was to evaluate the removal efficiencies of adsorption trap for formaldehyde and microorganisms as indoor pollutants which permeated into the Ringer's solution. Dissolved formaldehyde in the solution was increased with the injection dose time. The amount of dissolved formaldehyde was 67.5 $\pm$ 9.5% in Ringer's solution when injection dose time was controlled about 7hrs. An adsorption trap was designed for preventing formaldehyde and microorganisms to be permeated into Ringer's solution. The adsorption trap was packed with 0.4g of active carbon (60/80 mesh) in a sterilized plastic tube (7.79 cm length, 0.46 cm i.d.) and both ends were packed with glass wool. Devised infusion set equipped with the adsorption trap showed 99.9% of removal efficiency for formaldehyde. Microorganism numbers detected on sterilized water for injection and 5% dextrose infusion used in the hospital were 2,695 $\times 10^3$ cells/l and 4,190 $\times 10^3$ cells/l, respectively. Removal efficiency by the adsorption trap was 92.3 $\pm$ 8.5% as for microorgnisms.

• 한국해양공학회지
• /
• 제22권5호
• /
• pp.39-43
• /
• 2008

For a partially filled and deeply submersed membrane container, an analytic solution for similarity shape was studied. The static shape of a membrane container can be expressed as a set of nonlinear ordinary differential equations. These equations are combined into an integrable equation. The solution of the equation is derived in terms of elliptic integrals, the arguments of which contain an unknown at the point of inflection. The point of inflection is determined by using the boundary condition at a separating point. Some characteristic values of the similarity shape were evaluated and the shapes are illustrated.

• 한국지능시스템학회:학술대회논문집
• /
• 한국퍼지및지능시스템학회 1998년도 The Third Asian Fuzzy Systems Symposium
• /
• pp.512-516
• /
• 1998

Fuzzy mathematical programming (FMP) can be treated an uncertainty condition using fuzzy concept. Further, it can be extended to the multiple objective (or goal) programming problem, naturally. But we feel that FMP have some shortcomings such as the fuzzy number in FMP is the one dimesional possibility set, so it can not be represented the relationship between them, and, in spite of FMP includes some (uncertainty) fuzzy paramenters, many alogrithms are only obtained a crisp solution.In this study, we propose a method of FMS. Our method use the scenario approach (or fuzzy random variables) to represent the relationship between fuzzy numbers, and can obtain the fuzzy solution.

• 대한기계학회논문집
• /
• 제15권2호
• /
• pp.396-403
• /
• 1991

A solution is presented for the computation of the elastic-creep stresses in a hollow cylinder subjected to nonaxisymmetric temperature distribution. The creep problem is treated by the Maxwell creep model. Laplace transformation is used for reformation of the governing equation of elastic problem and Hooke's law in a function of .gamma. , .theta. , and creep constant. The governing equation is set up using the Airy stress function which leads to the biharmonic equation. The solution is obtained by using Fourer series method and Laplace inverse method used to obtain the stress components which include the variation of time. This solution shows excellent agreement with Lamkin's and Boley & Weiner's solution. The viscoelastic stresses are also obtained for the fuel rob tube subjecting nonaxisymmetric thermal load.

• 에너지공학
• /
• 제13권2호
• /
• pp.128-132
• /
• 2004

본 연구에서는 급전계획의 파레토최적해를 구하는 새로운 방법을 제시하였다. 이를 위하여, 고찰기간에 대해 총 오염물질배출량을 고려하여 최적경제부하배분을 할 수 있는 동적계획법을 도입하였으며, 최적급전계획의 결과를 군으로 얻을 수 있는 파레토최적해를 얻는 방법을 개발하였다. 이 결과, 의사결정자는 파레토최적해를 얻을 수 있으며, 이중에서 하나의 해를 선택하여 사용할 수 있게 되었다. 제안한 방법을 시험계통에 적용하여 유용성을 검증하였다.

• Journal of applied mathematics & informatics
• /
• 제9권2호
• /
• pp.717-730
• /
• 2002

In this paper we use measure theory to solve a wide range of the nonlinear programming problems. First, we transform a nonlinear programming problem to a classical optimal control problem with no restriction on states and controls. The new problem is modified into one consisting of the minimization of a special linear functional over a set of Radon measures; then we obtain an optimal measure corresponding to functional problem which is then approximated by a finite combination of atomic measures and the problem converted approximately to a finite-dimensional linear programming. Then by the solution of the linear programming problem we obtain the approximate optimal control and then, by the solution of the latter problem we obtain an approximate solution for the original problem. Furthermore, we obtain the path from the initial point to the admissible solution.

• 한국경영과학회지
• /
• 제19권1호
• /
• pp.69-83
• /
• 1994

This paper deals with a capacitated ring-star network design problem (CRSNDP) with node capacity constraints. The CRSNDP is formulated as a mixed 0-1 integer problem, and a 2-phase heuristic solution procedure, ADD & VAM and RING, is developed, in which the CRSNDP is decomposed into two subproblems : the capacitated facility location problem (CFLP) and the traveling sales man problem (TSP). To solve the CFLP in phase I the ADD & VAM procedure selects hub nodes and their appropriate capacity from a candidate set and then assigns them user nodes under node capacity constraints. In phase II the RING procedure solves the TSP to interconnect the selected hubs to form a ring. Finally a solution of the CRSNDP can be achieved through combining two solution of phase I & II, thus a final design of the capacitated ring-star network is determined. The analysis of computational results on various random problems has shown that the 2-phase heuristic procedure produces a solution very fast even with large-scale problems.

• 한국산학기술학회논문지
• /
• 제5권1호
• /
• pp.7-12
• /
• 2004

급액관리에 관련된 단계를 4단계로 나누었으며, 각 단계별 수분 이동 저항을 규명하고, 단계 중에서 급액 상황에 따라 관련 인자의 priority를 설정함으로써 펄라이트 자루재배할 경우 율속인자 중심의 적정 급액관리 기준을 제안하였다. 특히, 급액관리의 가장 중요한 율속인자인 뿌리까지의 수분도달거리를 최소한으로 하여 필요한 수분을 공급하는 과정과 역사성을 부여한 뿌리발달 조장이 가장 중요한 것으로 판명되었다.