• Title/Summary/Keyword: conflicting objectives

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Multiobjective Vehicle Scheduling Problem with Time and Area-Dependent Travel Speeds: Scheduling Algorithm and Expert System (시간대 및 구역의존 차량이동속도를 고려하는 다목적차량일정문제: 일정계획해법과 전문가시스템)

  • Park, Yang-Byung
    • Journal of Korean Institute of Industrial Engineers
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    • v.23 no.4
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    • pp.621-633
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    • 1997
  • This paper is concerned with the multiobjective vehicle scheduling problem with time and area-dependent travel speeds(MVSPTD), in which two conflicting objectives are explicitly treated and the travel speed between two locations depends on the passing area and time of day. The two objectives are the minimization of total vehicle travel time and the minimization of total weighted tardiness. First, I construct a mixed integer linear programming formulation of the MVSPTD, and present o heuristic algorithm that builds the vehicle schedules based on the savings computed. The results of computational experiments showed that the heuristic performs very well. Finally, I propose an expert system for vehicle scheduling in the MVSPTD. Its whole process is executed under VP-Expert expert system environment.

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Response Surface Approximation for Fatigue Life Prediction and Its Application to Multi-Criteria Optimization With a Priori Preference Information (피로수명예측을 위한 반응표면근사화와 순위선호정보를 가진 다기준최적설계에의 응용)

  • Baek, Seok-Heum;Cho, Seok-Swoo;Joo, Won-Sik
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.33 no.2
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    • pp.114-126
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    • 2009
  • In this paper, a versatile multi-criteria optimization concept for fatigue life prediction is introduced. Multi-criteria decision making in engineering design refers to obtaining a preferred optimal solution in the context of conflicting design objectives. Compromise decision support problems are used to model engineering decisions involving multiple trade-offs. These methods typically rely on a summation of weighted attributes to accomplish trade-offs among competing objectives. This paper gives an interpretation of the decision parameters as governing both the relative importance of the attributes and the degree of compensation between them. The approach utilizes a response surface model, the compromise decision support problem, which is a multi-objective formulation based on goal programming. Examples illustrate the concepts and demonstrate their applicability.

Bi-Criteria Process Routing Based on COMSOAL Approach

  • Lee Sung-Youl
    • Management Science and Financial Engineering
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    • v.11 no.2
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    • pp.45-60
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    • 2005
  • This paper investigates the application of the computer method COMSOAL (Computer Method of Sequencing Operations for Assembly Lines) to the process routing (PR) problem with multiple objectives. In any computer aided process planning (CAPP) system, one of the most critical activities for manufacturing a part could be to generate the sequence that optimizes production time, production cost, machine utilization or with multiple these criteria. The COMSOAL has been adopted to find the optimum sequence of operations that optimizes two major conflicting criteria : production cost and production quality. The COMSOAL is here slightly modified to simultaneously generate and evaluate a set of possible solutions (called as population) instead of processing a solution stepwise in each iteration. The significant features of the COMSOAL include : no parameters settings needed, and a guarantee of feasible solutions. Experimental results show that COMSOAL is a simple but powerful method to quickly generate multiple feasible solutions which are as good as the ones obtained from several other well-known process routing algorithms.

Response Surface Approximation for Fatigue Life Prediction and Its Application to Compromise Decision Support Problem (피로수명예측을 위한 반응표면근사화와 절충의사결정문제의 응용)

  • Baek, Seok-Heum;Cho, Seok-Swoo;Jang, Deuk-Yul;Joo, Won-Sik
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.1187-1192
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    • 2008
  • In this paper, a versatile multi-objective optimization concept for fatigue life prediction is introduced. Multi-objective decision making in engineering design refers to obtaining a preferred optimal solution in the context of conflicting design objectives. Compromise decision support problems are used to model engineering decisions involving multiple trade-offs. These methods typically rely on a summation of weighted attributes to accomplish trade-offs among competing objectives. This paper gives an interpretation of the decision parameters as governing both the relative importance of the attributes and the degree of compensation between them. The approach utilizes a response surface model, the compromise decision support problem, which is a multi-objective formulation based on goal programming. Examples illustrate the concepts and demonstrate their applicability.

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Multiple Objective Input-Output Analysis in Energy and Environmental Planning (다목적 산업연관분석을 이용한 에너지.환경계획)

  • 강희정;차재호;유왕진
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.21 no.46
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    • pp.207-219
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    • 1998
  • Multiple Objective Programming(MOP) has been suggested for the solution of completed decision problems. Decision analysis in numerous areas, including energy and environmental planning, necessarily requires consideration of multiple conflicting objectives, MOP has been successfully applied to a number of these problems. The objective of this paper is to present a MOP process which are integrated model with the Input-Output(I-O) analysis for energy and environment planning in industrial sectors. In the model, three objectives are observed such as (1) value added (2) total energy consumption and (3) environmental impacts. Special emphasis is placed on the police implications of industrial structures.

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An Evaluation of Multi-Reservoir Operation Weighting Coefficients Using Fuzzy DEA taking into account Inflow Variability (유입량의 변동성을 고려한 Fuzzy DEA 기반의 댐 군 연계운영 가중치 대안 평가)

  • Kim, Yong-Ki;Kim, Jae-Hee;Kim, Sheung-Kown
    • IE interfaces
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    • v.24 no.3
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    • pp.220-230
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    • 2011
  • The multi-reservoir operation problem for efficient utilization of water resources involves conflicting objectives, and the problem can be solved by varying weight coefficient on objective functions. Accordingly, decision makers need to choose appropriate weight coefficients balancing the trade-offs among multiple objectives. Although the appropriateness of the weight coefficients may depend on the total amount of water inflow, reservoir operating policy may not be changed to a certain degree for different hydrological conditions on inflow. Therefore, we propose to use fuzzy Data Envelopment Analysis (DEA) to rank the weight coefficients in consideration of the inflow variation. In this approach, we generate a set of Paretooptimal solutions by applying different weight coefficients on Coordinated Multi-reservoir Operating Model. Then, we rank the Pareto-optimal solutions or the corresponding weight coefficients by using Fuzzy DEA model. With the proposed approach, we can suggest the best weight coefficients that can produce the appropriate Pareto-optimal solution considering the uncertainty of inflow, whereas the general DEA model cannot pinpoint the best weight coefficients.

Multi-objective structural optimization of spatial steel frames with column orientation and bracing system as design variables

  • Claudio H. B. de Resende;Luiz F. Martha;Afonso C. C. Lemonge;Patricia H. Hallak;Jose P. G. Carvalho;Julia C. Motta
    • Advances in Computational Design
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    • v.8 no.4
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    • pp.327-351
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    • 2023
  • This article explores how multi-objective optimization techniques can be used to design cost-effective and structurally optimal spatial steel structures, highlighting that optimizing performance can be as important as minimizing costs in real-world engineering problems. The study includes the minimization of maximum horizontal displacement, the maximization of the first natural frequency of vibration, the maximization of the critical load factor concerning the first global buckling mode of the structure, and weight minimization as the objectives. Additionally, it outlines a systematic approach to selecting the best design by employing four different evolutionary algorithms based on differential evolution and a multi-criteria decision-making methodology. The paper's contribution lies in its comprehensive consideration of multiple conflicting objectives and its novel approach to simultaneous consideration of bracing system, column orientation, and commercial profiles as design variables.

Development of Fitness and Interactive Decision Making in Multi-Objective Optimization (다목적 유전자 알고리즘에 있어서 적합도 평가방법과 대화형 의사결정법의 제안 )

  • Yeboon Yun;Dong Joon Park;Min Yoon
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.45 no.4
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    • pp.109-117
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    • 2022
  • Most of real-world decision-making processes are used to optimize problems with many objectives of conflicting. Since the betterment of some objectives requires the sacrifice of other objectives, different objectives may not be optimized simultaneously. Consequently, Pareto solution can be considered as candidates of a solution with respect to a multi-objective optimization (MOP). Such problem involves two main procedures: finding Pareto solutions and choosing one solution among them. So-called multi-objective genetic algorithms have been proved to be effective for finding many Pareto solutions. In this study, we suggest a fitness evaluation method based on the achievement level up to the target value to improve the solution search performance by the multi-objective genetic algorithm. Using numerical examples and benchmark problems, we compare the proposed method, which considers the achievement level, with conventional Pareto ranking methods. Based on the comparison, it is verified that the proposed method can generate a highly convergent and diverse solution set. Most of the existing multi-objective genetic algorithms mainly focus on finding solutions, however the ultimate aim of MOP is not to find the entire set of Pareto solutions, but to choose one solution among many obtained solutions. We further propose an interactive decision-making process based on a visualized trade-off analysis that incorporates the satisfaction of the decision maker. The findings of the study will serve as a reference to build a multi-objective decision-making support system.

A Qualitative Study on Attitude, Acceptability, and Adaptation for Home-delivered Meal Services in the Korean Elderly from the Perspective of Life Context (질적 연구를 통한 삶의 맥락적 관점에서의 노인의 도시락 및 밑반찬 배달 서비스에 대한 수용 태도 및 적응에 대한 이해)

  • Hwang, Ji-Yun;Kim, Bokyoung;Kim, Kirang
    • Korean Journal of Community Nutrition
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    • v.19 no.5
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    • pp.459-467
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    • 2014
  • Objectives: The purpose of this study was to suggest the strategies for improvement of home-delivered meal services for the elderly, to identify reasons for recipients to get started with the services and to evaluate the attitude, acceptability and adaptation of recipients to the services from the perspective of life context. Methods: The data was collected through face-to-face in-depth interviews with eighteen low-income elderly recipients of home-delivered meals and analyzed using a qualitative research method. Results: The results were deduced as four themes which comprised of long-term vulnerable socioeconomic contexts resulted in entry to the services, conflicting acceptability to the services, passive adaptation to taking the services, and positive practices to cope with supplement free meals or other services. The service participation was initiated because of a combination of prolonged, vulnerable socioeconomic contexts, including poverty and unexpected life events such as diseases, disability, living alone, aging and unemployment. With regard to taking the services, conflicting acceptability was observed: positive aspects including saving living cost and good quality of meals, and negative aspects including lack of a tailored service and feeling of stigma. Although the recipients needed an individualized service, they did not express their needs and demands for the services and they accepted the unavailability as an accustomed, prolonged vulnerable socioeconomic context. With regard to lack of tailored services, either self-solution such as modification of eating patterns or community-based network and services were used. Conclusions: We suggest that a system to concretely identify recipients' attitude, acceptability and adaptation for home-delivered meal services should be developed in the establishment of a tailored nutrition support system for the low-income elderly.

Differential effects of various dietary proteins on dextran sulfate sodium-induced colitis in mice

  • Eunyeong, Ahn;Hyejin, Jeong;Eunjung, Kim
    • Nutrition Research and Practice
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    • v.16 no.6
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    • pp.700-715
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    • 2022
  • BACKGROUND/OBJECTIVES: Chronic colitis is a risk factor for colorectal cancer (CRC) development in both animals and humans. Previously, we reported that a diet rich in protein (with casein as the protein source) significantly increased the risk of mouse CRC development in a dose-dependent manner. In this study, we investigated the effects of different protein sources on the risk of colitis development. MATERIALS/METHODS: Balb/c mice were divided into 7 experimental groups: 20% casein (20C), 20C-dextran sulfate sodium (DSS), 40% casein-DSS (40CD), 40% whey protein-DSS (40WD), 40% soy protein-DSS (40SD), 40% white meat-DSS (40WMD), and 40% red meat-DSS (40RMD). Mice were fed an experimental diet for 4 wk and received 3% DSS in their drinking water for 6 days during the 4th wk of the experimental period. RESULTS: Compared to other groups, the 40CD group showed the most aggravated colitis with increased disease activity and inflammatory markers. In the 40RMD group, interleukin (IL)-6 levels were the highest among all the groups. The 40SD group showed conflicting effects, for example, elevated mortality and disease activity but decreased nitric oxide (NO) levels. The 40WD group showed attenuated colitis with increased IL-10 levels and decreased NO levels. The 40WMD group showed conflicting effects, including decreased NO levels and elevated fecal lipocalin-2 and IL-6 levels. CONCLUSIONS: These results suggest that, at levels of 40% in the diet, casein and red meat exacerbate colitis, whereas whey protein mitigates it the most effectively.