• Title, Summary, Keyword: 다목적함수

Search Result 151, Processing Time 0.037 seconds

Applications of the Multiobjective Optimization Method in Main Particular Selection (선박의 주요치수 선정에 있어서 다목적함수 최적화의 응용)

  • Dong-Kon Lee;Soo-Young Kim;Soo-Chul Shin
    • Journal of the Society of Naval Architects of Korea
    • /
    • v.32 no.2
    • /
    • pp.10-21
    • /
    • 1995
  • In this paper, main particulars of a ship are optimized by the multiobjective optimization method which can offer more information to designer. To analyze the effect of a ship building cost and operating cost in the optimum design of a ship, the multiobjective optimization is performed with objective functions of building and operating costs. And Required Freight Rate(RFR) is also calculated as dependent variable. The design model was developed for the Liquefied Natural Gas(LNG) carrier with longer operating distance. The LNG carrier has some characteristics such as higher speed and building cost in comparison with other commercial ships.

  • PDF

A Study on Strengthened Genetic Algorithm for Multi-Modal and Multiobjective Optimization (강화된 유전 알고리듬을 이용한 다극 및 다목적 최적화에 관한 연구)

  • Lee Won-Bo;Park Seong-Jun;Yoon En-Sup
    • Journal of the Korean Institute of Gas
    • /
    • v.1 no.1
    • /
    • pp.33-40
    • /
    • 1997
  • An optimization system, APROGA II using genetic algorithm, was developed to solve multi-modal and multiobjective problems. To begin with, Multi-Niche Crowding(MNC) algorithm was used for multi-modal optimization problem. Secondly, a new algorithm was suggested for multiobjective optimization problem. Pareto dominance tournaments and Sharing on the non-dominated frontier was applied to it to obtain multiple objectives. APROGA II uses these two algorithms and the system has three search engines(previous APROGA search engine, multi-modal search engine and multiobjective search engine). Besides, this system can handle binary and discrete variables. And the validity of APROGA II was proved by solving several test functions and case study problems successfully.

  • PDF

Improved Automatic Lipreading by Multiobjective Optimization of Hidden Markov Models (은닉 마르코프 모델의 다목적함수 최적화를 통한 자동 독순의 성능 향상)

  • Lee, Jong-Seok;Park, Cheol-Hoon
    • The KIPS Transactions:PartB
    • /
    • v.15B no.1
    • /
    • pp.53-60
    • /
    • 2008
  • This paper proposes a new multiobjective optimization method for discriminative training of hidden Markov models (HMMs) used as the recognizer for automatic lipreading. While the conventional Baum-Welch algorithm for training HMMs aims at maximizing the probability of the data of a class from the corresponding HMM, we define a new training criterion composed of two minimization objectives and develop a global optimization method of the criterion based on simulated annealing. The result of a speaker-dependent recognition experiment shows that the proposed method improves performance by the relative error reduction rate of about 8% in comparison to the Baum-Welch algorithm.

Impact Performance Optimization of Auto-Sensing Breaker using Multi-objective Function (다목적함수를 이용한 지능형 브레이커의 타격성능 최적화)

  • Lee, Dae-Hee;Noh, Dae-Kyung;Park, Sung-Su;Lee, Geun-Ho;Kang, Young-Ky;Cho, Jae-Sang;Jang, Joo-Sup
    • Journal of the Korea Society for Simulation
    • /
    • v.26 no.4
    • /
    • pp.11-21
    • /
    • 2017
  • This paper discusses the design parameter sensitivity analysis and multi-objective function optimization for improving the impact performance of an auto-sensing breaker based on the analytical model of the same, which secured reliability in a previous research. The study aims to improve both impact power and stability by complementing the existing research that only improved the impact power. The study sequence is as follows: first, the analysis scenarios for the accurate sensitivity analysis and optimization are set up. Second, the sensitivity of the design parameter of the auto-sensing breaker is analyzed, and the variables with high sensitivity are extracted. Third, the extracted variables are used to optimize the multi-objective functions, and the optimized performance is compared with the initial performance to see how the impact performance on the existing auto-sensing breaker has improved. This study is based on domestic technology, and will allow the development of products with a better blowing performance than their existing overseas counterparts.

A Study for an Automatic Calibration of Urban Runoff Model by the SCE-UA (집합체 혼합진화 알고리즘을 이용한 도시유역 홍수유출 모형의 자동 보정에 관한 연구)

  • Kang, Tae-Uk;Lee, Sang-Ho;Kang, Shin-Uk;Park, Jong-Pyo
    • Journal of Korea Water Resources Association
    • /
    • v.45 no.1
    • /
    • pp.15-27
    • /
    • 2012
  • SWMM (Storm Water Management Model) has been widely used in the world as a typical model for flood runoff analysis of urban areas. However, the calibration of the model is difficult, which is an obstacle to easy application. The purpose of the study is to develop an automatic calibration module of the SWMM linked with SCE-UA (Shuffled Complex Evolution-University of Arizona) algorithm. Generally, various objective functions may produce different optimization results for an optimization problem. Thus, five single objective functions were applied and the most appropriate one was selected. In addition to the objective function, another objective function was used to reduce peak flow error in flood simulation. They form a multiple objective function, and the optimization problem was solved by determination of Pareto optima. The automatic calibration module was applied to the flood simulation on the catchment of the Guro 1 detention reservoir and pump station. The automatic calibration results by the multiple objective function were more excellent than the results by the single objective function for model assessment criteria including error of peak flow and ratio of volume between observed and calculated flow. Also, the verification results of the model calibrated by the multiple objective function were reliable. The program could be used in various flood runoff analysis in urban areas.

Optimum Structural Design of Tankers Using Multi-objective Optimization Technique (다목적함수 최적화기법을 이용한 유조선의 최적구조설계)

  • 신상훈;장창두;송하철
    • Journal of the Computational Structural Engineering Institute of Korea
    • /
    • v.15 no.4
    • /
    • pp.591-598
    • /
    • 2002
  • In the ship structural design, the material cost of hull weight and the overall cost of construction processes should be minimized considering safety and reliability. In the past, minimum weight design has been mainly focused on reducing material cost and increasing dead weight reflect the interests of a ship's owner. But, in the past experience, the minimum weight design has been inevitably lead to increasing the construction cost. Therefore, it is necessary that the designer of ship structure should consider both structural weight and construction cost. In this point of view, multi-objective optimization technique is proposed to design the ship structure in this study. According to the proposed algorithm, the results of optimization were compared to the structural design of actual VLCC(Very Large Crude Oil Carrier). Objective functions were weight cost and construction cost of VLCC, and ES(Evolution Strategies), one of the stochastic search methods, was used as an optimization solver. For the scantlings of members and the estimations of objectives, classification rule was adopted for the longitudinal members, and the direct calculation method, GSDM(Generalized Slope Deflection Method), lot the transverse members. To choose the most economical design point among the results of Pareto optimal set, RFR(Required Freight Rate) was evaluated for each Pareto point, and compared to actual ship.

A study on fuzzy goals of system with hierarchical structure (계층적구조를 갖는 시스템의 FUZZY GOALS에 관한 연구)

  • 박주녕;송서일
    • Journal of the Society of Korea Industrial and Systems Engineering
    • /
    • v.12 no.20
    • /
    • pp.97-104
    • /
    • 1989
  • In this thesis, each objective functions with hierarchical system Bi-level linear programming (BLPP) Problem applications to fuzzy set theory conducted multiple objective programming problem. Using linear fuzzy membership functions make a change typical BLPP and presents modified method turn to account established BLPP method, presents operation results lead to example. Fuzzy Bi-level linear programming problem (FBLPP) can be natural describe realities of life then BLPP.

  • PDF

Optimization of Multi-objective Function based on The Game Theory and Co-Evolutionary Algorithm (게임 이론과 공진화 알고리즘에 기반한 다목적 함수의 최적화)

  • Sim, Kwee-Bo;Kim, Ji-Yoon;Lee, Dong-Wook
    • Journal of Korean Institute of Intelligent Systems
    • /
    • v.12 no.6
    • /
    • pp.491-496
    • /
    • 2002
  • Multi-objective Optimization Problems(MOPs) are occur more frequently than generally thought when we try to solve engineering problems. In the real world, the majority cases of optimization problems are the problems composed of several competitive objective functions. In this paper, we introduce the definition of MOPs and several approaches to solve these problems. In the introduction, established optimization algorithms based on the concept of Pareto optimal solution are introduced. And contrary these algorithms, we introduce theoretical backgrounds of Nash Genetic Algorithm(Nash GA) and Evolutionary Stable Strategy(ESS), which is the basis of Co-evolutionary algorithm proposed in this paper. In the next chapter, we introduce the definitions of MOPs and Pareto optimal solution. And the architecture of Nash GA and Co-evolutionary algorithm for solving MOPs are following. Finally from the experimental results we confirm that two algorithms based on Evolutionary Game Theory(EGT) which are Nash GA and Co-evolutionary algorithm can search optimal solutions of MOPs.

MTF Compensation for KOMPSAT-1 EOC Images (다목적 실용위성 1호 EOC 영상에 대한 MTF 보상)

  • 강치호;최해진
    • Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
    • /
    • /
    • pp.22-25
    • /
    • 2003
  • EOC(Electro Optical Camera)는 한반도 및 전 세계 육지 영역 관측용으로 설계되었다. EOC는 1999년 12월 21일 발사된 다목적 실용위성 1호에 탑재되어 가시광 대역(510 ~730nm)으로 입사하는 복사 정보를 수집해 왔다. 획득된 EOC 영상 자료는 다목적 실용위성 1호의 탑재체 자료전송 시스템(Payload Data Transmission System, PDTS)을 통해 지상으로 전송되며, 수신된 자료에 대한 방사 보정 및 기하 보정 등의 일련의 전처리(Pre-processing) 과정을 거쳐 EOC 표준 영상이 생성된다. EOC 영상에 대한 MTF 보상은 방사 보정 후 수행될 수 있으며, 다목적 실용위성 지상국에서는 사용자의 요구에 따라 EOC 영상에 대한 MTF 보상을 수행하고 그 결과를 제공한다. MTF 보상은 EOC의 점 확산 함수(Point Spread Function)를 이용하여 수행되며, 현재 Wiener 필터를 이용하여 수행되고 있다. 본문에서는 현재 다목적 실용위성 1호 영상처리시스템의 EOC 영상에 대한 MTF 보상을 소개하고, EOC의 점 확산 함수에 기초하여 역 필터(Inverse Filter) 및 의사 역 필터(Pseudo Inverse Filter)를 제작, EOC 영상에 대한 MTF 보상 수행 후 그 결과를 Wiener 필터를 이용한 결과와 비교, 분석한다.

  • PDF

Development of a Method for the Generator Maintenance Scheduling using Fuzzy Integer Programming (퍼지 정수계회법을 이용한 발전기 보수유지계획 수립 수법의개발)

  • 최재석;도대호
    • Journal of Korean Institute of Intelligent Systems
    • /
    • v.7 no.5
    • /
    • pp.77-85
    • /
    • 1997
  • A new technique using integer programming based on fuzzy multi-criteria function is proposed for generator maintenance scheduling. Minimization of maintenance delay cost and maximization of supply reserve power are considered for fuzzy multi-criteria function To obtain an optimal solution for gen- ,:rator maintenance scheduling under fuzzy environment, fuzzy multi-criteria integer programming is )used. In the maintenance scheduling, a characteristic feature of the presented approach is that the crisp conaitraints with uncertainty can be taken into account by using fuzzy set theory and so more flexible solution Ian he obtained. The effectiveness of the proposed approach is demonstrated by the simulation results.

  • PDF