• Title/Summary/Keyword: objective function

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3 Phase Optimal Power Flow for the Operation of Distributed Generation Systems (분산전원 계통 운용을 위한 3상 최적조류계산)

  • Kim, Young-Gon;Song, Hwa-Chang
    • Proceedings of the KIEE Conference
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    • 2009.07a
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    • pp.482_483
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    • 2009
  • This paper presents a method of finding the optimal operating point minimizing a given objective function with 3 phase power flow equations and operational constraints, called 3 phase optimal power flow. 3 phase optimal power flow can provide operation and control strategies for the distribution systems with distributed generation assets, which might be frequently in unbalanced conditions assuming that high penetration rate of renewable energy sources in the systems. As the solution technique, this paper adopts a standard particle swarm optimization (PSO).

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A Study on the Electric Field Source Modeling of Naval Vessel Utilizing Material Sensitivity (매질 민감도를 이용한 함정 전기장 신호원 모델링에 관한 연구)

  • Chung, Hyun-Ju;Yang, Chang-Seob;Jeon, Jae-Jin;Jung, Gi-Woo;Kim, Dong-Hun
    • Proceedings of the KIEE Conference
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    • 2009.07a
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    • pp.658_659
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    • 2009
  • This paper deals with the numerical implementation of the material sensitivity analysis, which is used to efficiently determine an optimal electric current distribution on a ship hull by corrosion of ship. A material sensitivity formula for the forward problem formulated in terms of the equivalent current method is analytically derived. Then, the components of the adjoint system including the electric pseudo-source are thoroughly investigated in order to obtain the first-order gradient information of an objective function with respect to the electric current. The purposed method has been successfully applied to a model ship and the predicted result on the underwater electric field due to corrosion of ship have been compared to that computed by FNREMUS software.

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A Restoration Algorithm using Moving the tie Switch in Distribution System in case of Fault Occur in Power system Substation MTR (변전소 내 주변압기 사고 발생 시 배전계통 연계점 이동을 통한 복구 알고리즘)

  • Hong, Jun-Ho;Lee, Seung-Jae;Choi, Myeon-Song;Lim, Il-Hyung;Kim, Tae-Wan
    • Proceedings of the KIEE Conference
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    • 2009.07a
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    • pp.159_160
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    • 2009
  • In this paper proposes a new algorithm of efficiency outage restoration using a outage load switching to a healthy MTR a fault occurrence at a MTR. In addtion, proposed algorithm includes a outage restoration method which keeps MTR optimal capacity with reorganization of distribution network in case it can not restore outage state loads caused by shortage of healthy MTR remain capacity. In case that proposed sequence still can not complete restoration, this paper suggests a efficiency outage restoration with objective function included priority in outage loads.

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Development of Evolution Program for Dynamic Channel Assignment in Wireless Telecommunication Network (무선통신 네트워크에서 동적채널할당을 위한 진화프로그램의 개발)

  • Kim, Sung-Soo;Han, Kwang-Jin;Lee, Jong-Hyun
    • IE interfaces
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    • v.14 no.3
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    • pp.227-235
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    • 2001
  • There is a rapidly growing demand for wireless telecommunication. However, the number of usable channel is very limited. Therefore, the problem of channel assignment becomes more and more important to use channels as efficiently as possible. The objective of this paper is to develop an evolution program (EP) to find an efficient dynamic channel assignment method for minimum interference among the channels within reasonable time. The series of specific channel number is used as a representation of chromosome. The only changed chromosomes by crossover and mutation are evaluated in each generation to save computation time and memory for the progress of improved EP. We can easily differentiate the fitness value of each chromosome using proposed evaluation function. We also control the weighting factor of the mutation rate and the used number of elitist chromosomes for the speed of convergence to the optimal solution.

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A Stochastic Partial Backorder Inventory Model with a Backorder Ratio Depending on Backorder periods (부재고기간(負在庫期間)에 의존하는 부재고비율(負在庫比率)을 갖는 확률적(確率的) 부분부재고(部分負在庫)모델)

  • Kim, Jung-Ja
    • Journal of Korean Institute of Industrial Engineers
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    • v.24 no.1
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    • pp.127-136
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    • 1998
  • This paper presents a stochastic partial backorder inventory model for the situation in which demand follows normal distribution and back order ratio during that stockout period decreases exponentially according to the length of backorder period. In the paper, an objective function is formulated to minimize the average annual cost, which is the sum of the ordering, carrying, time-proportional backordering, and lost sales cost. And then sensitivity analysis for various exponential backorder ratios and standard deviations of leadtime demand are presented. The inventory model in the paper is reduced to a backorder model and lost sales model, when backorder ratio is 1 and 0, respectively.

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A Production Schedule for Load Leveling in a Block Assembly Shop (블록조립공장의 부하평준화를 위한 생산일정계획)

  • Lee, Jae-Dong;Hong, Yu-Shin
    • IE interfaces
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    • v.7 no.2
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    • pp.75-85
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    • 1994
  • This paper presents a production scheduling model in a block assembly shop in shipbuilding industry. In a block assembly shop, the most important performance criterion is load leveling, which balances manpower and work area utilization through the planning horizon. The problem is formulated as a mixed-integer nonlinear programming(MINLP) problem of which objective function is to optimize load leveling. The developed MINLP problem can not be solvable due to computational complexity. The MINLP problem is decomposed into two stage mixed-integer linear programming (MILP) problems to obtain a good solution, but the decomposed MILP problems are still computationally intractable because of combinatorial complexity. Therfore, a heuristic method using linear programming is proposed to solve two stage MILP problems sequentially. The proposed heuristic generates a good production schedule within a reasonable computation time, and it is easily applicable for establishing the production schedule in a block assembly shop in shipbuilding industry.

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Efficient Operation Policy in a Closed-loop Tire Manufacturing System with EPR

  • Ko, Young-Dae;Hwang, Hark
    • Industrial Engineering and Management Systems
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    • v.8 no.3
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    • pp.162-170
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    • 2009
  • This paper deals with a closed-loop remanufacturing system with one manufacturer and one remanufacturer. The manufacturer sells new products bearing the 'Extended Producer Responsibility (EPR).' It is assumed that the manufacturer's collection rate of used products depends only on the buy-back cost, while that of the remanufacturer depends on the minimum allowed quality level of used products in addition to the buy-back cost. Through the development of mathematical models with the objective function of maximizing profit, we study an efficient operation policy of each party. The decision variables are the unit selling price of new products and remanufactured products, the unit buy-back cost of the used products of the manufacturer and remanufacturer, and the minimum allowed quality level. The validity of the model is examined through numerical examples and sensitivity analysis.

Combinatorial Optimization Model of Air Strike Packages based on Target Groups (표적군 기반 공격 편대군 조합 최적화 모형)

  • Cho, Sanghyeon;Lee, Moongul;Jang, Youngbai
    • Journal of Korean Institute of Industrial Engineers
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    • v.42 no.6
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    • pp.386-394
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    • 2016
  • In this research, in order to optimize the multi-objective function effectively, we suggested the optimization model to maximize the total destruction of ground targets and minimize the total damage of aircrafts and cost of air munitions by using goal programming. To satisfy the various variables and constraints of this mathematical model, the concept of air strike package is applied. As a consequence, effective attack can be possible by identifying the prior ground targets more quickly. This study can contribute to maximize the ROK air force's combat power and preservation of high value air asset in the war.

Optimum Shape for Buckling and Post-Buckling Behavior of a Laminated Composite Panel with I-type Stiffeners

  • Lee, Gwang-Rog;Yang, Won-Ho;Sub, Myung-Won
    • Journal of Mechanical Science and Technology
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    • v.16 no.10
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    • pp.1211-1221
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    • 2002
  • A shape optimization of stiffener was conducted to increase buckling load or failure load with stiffened laminated composite panel of I-type under compression loading. Design variables are cap length, web length, and/or thickness under the constraint of volume constancy. The objective function is buckling load and failure load of post-buckling based on Tsai-Hill theory using ABAQUS 5.8 for analysis and Optimizer on Broydon-Fletcher Goldfarb-Sharno Method and Augmented Lagrange Multiplier Method. The effects of relative length of a web and a cap of stiffener on buckling load and failure load of post-buckling were investigated with the results of optimum design.

Optimal Design of Mechanisms Using a Least Experimental Plan Method (최소 실험계획법을 이용한 기구의 최적설계)

  • 김충웅;박태원
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.18 no.11
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    • pp.2883-2893
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    • 1994
  • Use of computers in design is a trend in recent years. Mechanism design also uses computers extensively and the concept of optimal mechanism design is developed in many ways. Various authors presented methods based on sensitivity analysis but in these cases, the governing equation of the mechanism has to be derived and calculations become very complicated. In this papers, a method based on the least experimental plan is presented. To make a model of a mechanism, a general purpose mechanism analysis program is used. To obtain an optimal design of a mechanism, the relationship between design variables and the objective function is represented as the nonlinear equation. Optimal design variables are found by solving this derived equation and its result is verified. An example is presented to show the effectiveness of this method.