• Title/Summary/Keyword: engineering and decision-making problems

Search Result 254, Processing Time 0.032 seconds

Multi-level Shape Optimization of Lower Arm by using TOPSIS and Computational Orthogonal Array (TOPSIS와 전산직교배열을 적용한 자동차 로워암의 다수준 형상최적설계)

  • Lee, Kwang-Ki;Han, Seung-Ho
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.28 no.4
    • /
    • pp.482-489
    • /
    • 2011
  • In practical design process, designer needs to find an optimal solution by using full factorial discrete combination, rather than by using optimization algorithm considering continuous design variables. So, ANOVA(Analysis of Variance) based on an orthogonal array, i.e. Taguchi method, has been widely used in most parts of industry area. However, the Taguchi method is limited for the shape optimization by using CAE, because the multi-level and multi-objective optimization can't be carried out simultaneously. In this study, a combined method was proposed taking into account of multi-level computational orthogonal array and TOPSIS(Technique for Order preference by Similarity to Ideal Solution), which is known as a classical method of multiple attribute decision making and enables to solve various decision making or selection problems in an aspect of multi-objective optimization. The proposed method was applied to a case study of the multi-level shape optimization of lower arm used to automobile parts, and the design space was explored via an efficient application of the related CAE tools. The multi-level shape optimization was performed sequentially by applying both of the neural network model generated from seven-level four-factor computational orthogonal array and the TOPSIS. The weight and maximum stress of the lower arm, as the objective functions for the multi-level shape optimization, showed an improvement of 0.07% and 17.89%, respectively. In addition, the number of CAE carried out for the shape optimization was only 55 times in comparison to full factorial method necessary to 2,401 times.

Analysis of Crane Accidents by Using a Man-Machine System Model (인간-기계 시스템 모델에 의한 크레인 사망재해 분석)

  • Park, Jae-Hee;Park, Tae-Joo;Lim, Hyun-Kyo;Seo, Eun-Hong
    • Journal of the Korean Society of Safety
    • /
    • v.22 no.2 s.80
    • /
    • pp.59-66
    • /
    • 2007
  • As the need of handling heavy materials increases, various cranes are used in industries. However, the effectiveness of crane also entails industrial accidents such as falling, constriction etc. In fact, the number of fatal accidents caused by crane is still high in Korea. To find out the causes of the accidents in terms of human error, we developed a man-machine system model that consists of two axes; human information processing and crane life cycle. In the human information processing dimension, we simplified it as five functions; sensing and perception, decision making and memory, response etc. In the crane life cycle dimension, we divided it into nine phases; design, production, operation etc. For the 152 fatal accident records during 1999-2006 years, we classified them into 45 cells made by two axes. Then we identified the preceding causes of the classified crane accident based on performance shaping factors. As the results of statistical analysis, the overall trend of crane fatal accidents was described. For the cause analysis, wrong decision making in work plan phase shows the highest frequency. Next, the poor information input in crane operation followed in accident frequency. In ergonomics view, the problems of interface design in displays and controls made 11.8% of fatal accidents. Following the analysis, several ergonomic design guidelines to prevent crane accidents were suggested.

Exploring Topic Defining Patterns of Students in Interdisciplinary Capstone Design Class (캡스톤 디자인 수업에서 학생들의 주제 결정 패턴 탐색)

  • Byun, Moon Kyoung
    • Journal of Engineering Education Research
    • /
    • v.21 no.1
    • /
    • pp.14-26
    • /
    • 2018
  • The goal of this study was to explore topic defining patterns of students in interdisciplinary Capstone Design Class. Thematic analysis methodology was used to examine 85 Korean college students' lived experience of project topic generation which is for interdisciplinary capstone design class and Individual open-ended survey for constituted the data sources. Findings show four contexts of student's topic defining patterns using thematic analysis including (a) one leader's directed problem representation, (b) team common decision making after brainstorming, (c) empathy with professor proposed issue, (d) problems offered to students by corporate or research competitions. Based on research result, I could suggest instructional strategies of Capstone Design Class of teacher for helping their students' topic defining. It was necessary to minimize the opinions of the instructors at the beginning of class and minimize the number of team members. And also it provided a lot of opportunities to collaborate with companies in the topic selection process, it will help to develop the students' ability to determine the valuable topic in project.

New Criteria for the Consistency in Reasonable Pairwise Comparison Matrices (합리적 쌍대비교행렬에서 일관성에 대한 새로운 기준)

  • Kim, Jae-Bum;Cho, Yong-Gon;Kim, Yun-Bae;Cho, Keun-Tae
    • Journal of Korean Institute of Industrial Engineers
    • /
    • v.36 no.1
    • /
    • pp.1-6
    • /
    • 2010
  • The Analytic Hierarchy Process (AHP) has been applied widely in various decision making fields. One of advantages of the AHP is the consistency test. However, it has several problems such as the limit of its concept, the limit of 9 scales and stern criteria, contradictory pairwise comparison. In this paper, we propose new criteria for the consistency with more realistic and ideal conditions. To derive the criteria, we conduct the simulation and use the bootstrap method, which is one of resampling techniques in the simulation area.

Nitrate Risk Management by Multiobjective Decision-making Technique Using Fuzzy Sets (퍼지이론을 사용한 다기준의사결정기법에 의한 질산의 위해성 관리)

  • Lee, Yong-Woon
    • Journal of Environmental Impact Assessment
    • /
    • v.5 no.1
    • /
    • pp.47-60
    • /
    • 1996
  • Nitrate contamination problems from groundwater supplies have been reported throughout many countries in the world, including Korea. Nitrate salts can induce methemoglobinemia and possibly human gastric cancer. To reduce human health risk from nitrate in groundwater supplies, several nitrate risk-management strategies can be developed based on the acceptable level of human health risk, the reasonableness of nitrate-control cost, and the technical feasibility of nitrate-control methods. However, due to a lack of available information, assessing risk, cost and technical feasibility contains elements of uncertainty. In the present paper, a nitrate risk-management methodology using fuzzy sets in combination with a multiobjective decision-making (MODM) technique is developed to assist decision makers in evaluating, with uncertain information, various nitrate risk-management strategies in order to decide a proper strategy.

  • PDF

Managing Approximation Models in Multidisciplinary Optimization (다분야 최적화에서의 근사모델 관리기법의 활용)

  • 양영순;정현승;연윤석
    • Proceedings of the Computational Structural Engineering Institute Conference
    • /
    • 2000.10a
    • /
    • pp.141-148
    • /
    • 2000
  • In system design, it is not always possible that all decision makers can cooperate fully and thus avoid conflict. They each control a specified subset of design variables and seek to minimize their own cost functions subject to their individual constraints. However, a system management team makes every effort to coordinate multiple disciplines and overcome such noncooperative environment. Although full cooperation is difficult to achieve, noncooperation also should be avoided as possible. Our approach is to predict the results of their cooperation and generate approximate Pareto set for their multiple objectives. The Pareto set can be obtained according to the degree of one's conceding coupling variables in the other's favor. We employ approximation concept for modelling this coordination and the mutiobjective genetic algorithm for exploring the coupling variable space for obtaining an approximate Pareto set. The approximation management concept is also used for improving the accuracy of the Pareto set. The exploration for the coupling variable space is more efficient because of its smaller dimension than the design variable space. Also, our approach doesn't force the disciplines to change their own way of running analysis and synthesis tools. Since the decision making process is not sequential, the required time can be reduced comparing to the existing multidisciplinary optimization techniques. This approach is applied to some mathematical examples and structural optimization problems.

  • PDF

INTEGRATION OF SSM AND IDEF TECHNIQUES FOR ANALYZING DOCUMENT MANAGEMENT PROCESSES

  • Vachara Peansupap;Udtaporn Theingkuen
    • International conference on construction engineering and project management
    • /
    • 2009.05a
    • /
    • pp.725-731
    • /
    • 2009
  • Construction documents are recognized as an essential component for making a decision and supporting on construction processes. In construction, the management of project document is a complex process due to different factors such as document types, stakeholder involvement, document flow, and document flow processes. Therefore, inappropriate management of project documents can cause several impacts on construction work processes such as delay or poor quality of work. Several information and communication technologies (ICT) were proposed to overcome problems concerning document management practice in construction projects. However, the adoption of ICT may have some limitation on the compatibility of specific document workflow. Lack of understanding on designing document system may cause many problems during the use and implementation phase. Thus, this paper proposes the framework that integrates Soft System Methodology (SSM) concept and Integrated Definition Modeling Technique (IDEF) for analyzing document management system in construction project. Research methodology is classified as the case study. Five main construction building projects are selected as case studies. The qualitative data related to problems and processes are collected by interviewing construction project participants such as main contractors, owners, consultants, and designers. The findings from case study show the benefits of using SSM and IDEF. The use of SSM can help identify the problems in managing construction document in rich picture view whereas IDEF can illustrate the document flow in construction project in details. In addition, the idea of integrating these two concepts can be used to identify the root causes of process problems at the information level. As the results, this idea can be applied to analyze and design web-based document management system in the future.

  • PDF

EVOLUTION OF NUCLEAR FUEL MANAGEMENT AND REACTOR OPERATIONAL AID TOOLS

  • TURINSKY PAUL J.;KELLER PAUL M.;ABDEL-KHALIK HANY S.
    • Nuclear Engineering and Technology
    • /
    • v.37 no.1
    • /
    • pp.79-90
    • /
    • 2005
  • In this paper are reviewed the current status of nuclear fuel management and reactor operational aid tools. In addition, we indicate deficiencies in current capabilities and what future research is judged warranted. For the nuclear fuel management review the focus is on light water reactors and the utilization of stochastic optimization methods applied to the lattice, fuel bundle, core loading pattern, and for BWRs the control rod pattern/core flow design decision making problems. Significant progress in addressing separately each of these design problems on a single cycle basis is noted; however, the outstanding challenge of addressing the integrated design problem over multiple cycles under conditions of uncertainty remains to be addressed. For the reactor operational aid tools review the focus is on core simulators, used to both process core instrumentation signals and as an operator aid to predict future core behaviors under various operational strategies. After briefly reviewing the current status of capabilities, a more in depth review of adaptive core simulation capabilities, where core simulator input data are adjusted within their known uncertainties to improved agreement between prediction and measurement, is presented. This is done in support of the belief that further development of adaptive core simulation capabilities is required to further significantly advance the utility of core simulators in support of reactor operational aid tools.

A Study on Human-AI Collaboration Process to Support Evidence-Based National Innovation Monitoring: Case Study on Ministry of Oceans and Fisheries (Human-AI 협력 프로세스 기반의 증거기반 국가혁신 모니터링 연구: 해양수산부 사례)

  • Jung Sun Lim;Seoung Hun Bae;Kil-Ho Ryu;Sang-Gook Kim
    • Journal of Korean Society of Industrial and Systems Engineering
    • /
    • v.46 no.2
    • /
    • pp.22-31
    • /
    • 2023
  • Governments around the world are enacting laws mandating explainable traceability when using AI(Artificial Intelligence) to solve real-world problems. HAI(Human-Centric Artificial Intelligence) is an approach that induces human decision-making through Human-AI collaboration. This research presents a case study that implements the Human-AI collaboration to achieve explainable traceability in governmental data analysis. The Human-AI collaboration explored in this study performs AI inferences for generating labels, followed by AI interpretation to make results more explainable and traceable. The study utilized an example dataset from the Ministry of Oceans and Fisheries to reproduce the Human-AI collaboration process used in actual policy-making, in which the Ministry of Science and ICT utilized R&D PIE(R&D Platform for Investment and Evaluation) to build a government investment portfolio.

A Study on the Corporate Culture and the Organizational Effectiveness (기업문화와 조직유효성에 관한 연구)

  • 김재붕;양시영
    • Journal of Korean Society of Industrial and Systems Engineering
    • /
    • v.20 no.44
    • /
    • pp.425-446
    • /
    • 1997
  • In recent years, a scholars and a managers in business have taken a more interest on the effects of corporate culture on the organization effectiveness. The corporate culture has been recognized as one of the way to promote the organization performance and cope with the changes of the business environment. Edgar H. Shein defins the corporate culture as the that the pattern of basic assumptions that a given group has invented, discovered or developed in learning to cope with its problems of external adaptation and internal integration. The organization effectiveness is differently defined as the job satisfaction, job involvement, organizational commitment, organizational performance etc. The business culture help the employee (1) understand the values, the tradition, and the different management systems(decision-making basis, promotion, reward, behavior etc.) of the company, (2) make the performance-oriented decison and doings. Consequently, the excellent corporate culture would improve the organizational effectiveness. The purpose of this study is (1) to examine theoretically the content on the corporate culture and the organizational effectiveness, (2) to suggest the direction of the corporate culture management for both the management md the scholars.

  • PDF