• Title/Summary/Keyword: Procedures of problem design

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Safety Evaluation of Wheel-Rail System Based on Fracture Scenarios and Fracture Mechanics (파손시나리오에 의한 차륜-레일의 파괴역학적 안전성 평가)

  • Lee, Dong-Hyung;Seo, Jung-Won;Goo, Byeung-Chun;Kwon, Seok-Jin
    • Proceedings of the KSR Conference
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    • 2006.11b
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    • pp.80-84
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    • 2006
  • Fracture mechanics approach can be severly hampered unless considerable detailed specific knowledge is available. The problem of railway wheel-rail system fatigue design is currently undertaken by using assumed conservative design procedures. However, although the failure rate is low, the consequences of any such failure can be far reaching. It has been demonstrated that the tools available for effective management have limits. In the present study, the safety evaluation based on fracture mechanics is carried out. The critical crack size and remaining lifetime are calculated on the wheel for high-speed train.

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A Design for Integrated Logistics System with Inventory Control and Transportation Planning Problem (재고와 수송계획문제를 고려한 통합물류시스템 설계)

  • 우태희;조남호
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.21 no.48
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    • pp.37-52
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    • 1998
  • In many distribution systems important cost reductions and/or service improvements may be achieved by adopting an efficient inventory policy and proper selection of facilities. These efficiency improvements and service enhancements clearly require an integrated approach towards various logistical planning functions. The areas of inventory control and transportation planning need to be closely coordinated. The purpose of this paper is to construct an integrated model that can minimize the total cost of the transportation and inventory systems between multiple origin and destination points, where in origin point i has the supply of commodities and in destination point j requires the commodities. In this case, demands of the destination points are assumed random variables which have a known probability distribution. Using the lot-size reorder-point policy and the safety stock level that minimize total cost we find optimal distribution centers which transport the commodities to the destination points and suggest an optimal inventory policy to the selected distribution center. We also show if a demand greater than one unit will occur at a particular time, we describe the approximate optional replenishment policy from computational results of this lot-size reorder-point policy. This model is formulated as a 0-1 nonlinear integer programming problem. To solve the problem, this paper proposes heuristic computational procedures and a computer program with UNIX C language. In the usefulness review, we show the meaning and validity of the proposed model and exhibit the results of a comparison between our approach and the traditional approach, respectively.

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A Performance Comparison of the Partial Linearization Algorithm for the Multi-Mode Variable Demand Traffic Assignment Problem (다수단 가변수요 통행배정문제를 위한 부분선형화 알고리즘의 성능비교)

  • Park, Taehyung;Lee, Sangkeon
    • Journal of Korean Institute of Industrial Engineers
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    • v.39 no.4
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    • pp.253-259
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    • 2013
  • Investment scenarios in the transportation network design problem usually contain installation or expansion of multi-mode transportation links. When one applies the mode choice analysis and traffic assignment sequentially for each investment scenario, it is possible that the travel impedance used in the mode choice analysis is different from the user equilibrium cost of the traffic assignment step. Therefore, to estimate the travel impedance and mode choice accurately, one needs to develop a combined model for the mode choice and traffic assignment. In this paper, we derive the inverse demand and the excess demand functions for the multi-mode multinomial logit mode choice function and develop a combined model for the multi-mode variable demand traffic assignment problem. Using data from the regional O/D and network data provided by the KTDB, we compared the performance of the partial linearization algorithm with the Frank-Wolfe algorithm applied to the excess demand model and with the sequential heuristic procedures.

Analysis of class satisfaction with Peer Evaluation in Collaborative Learning-based classes (협력학습 기반 수업에서의 동료평가에 대한 수업 만족도 분석)

  • Jeong, Sun-Kyeong;Park, Nam-Su
    • Journal of Convergence for Information Technology
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    • v.12 no.3
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    • pp.158-170
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    • 2022
  • The purpose of this study is to analyze class satisfaction with peer evaluation in Collaborative Learning-based classes. For collaborative learning-based classes, problem-based learning and project-based learning were selected. Educational implications were derived by designing Instructional procedures of Collaborative Learning-based classes, Peer evaluation types and questionnaire design, Peer evaluation progress of Collaborative Learning-based classes, Class satisfaction research and analysis In Collaborative Learning-based classes. The subjects of the study were participants in Collaborative Learning-based classes selected as problem-based learning and project-based classes. For class satisfaction with peer evaluation in Collaborative Learning-based classes, a survey was conducted on 168 participants A University in Korea. The research tool was designed as Learning procedures for peer evaluation Collaborative Learning-based classes is Team Building, Plan to the Task, To do Task, Mid-check on task, Task completion, Presentation & Evaluation, Reflection & Self-Evaluation. The content validity of items was confirmed by CVR of 12 experts. In the research results, the average class satisfaction of peer evaluation is 4.05(SD=91), followed by class concentration, diligence, voluntary, learning atmosphere. As a result of t-testing the difference in class type between collaborate learning-based classes, the satisfaction of PBL was higher than that of PjBL and a statistically significant difference was observed. The result of this study have significance in providing implications for class design and operation for the application and expansion of peer evaluation in higher education. However, there is a limit to generalization as a result of research using convenience.

Development of Algorithm Design Worksheets using Algorithmic Thinking-based Problem Model in Programming Education for Elementary School Students (초등학생의 프로그래밍 학습을 위한 알고리즘적 사고 문제 모델 기반의 활동지 개발 및 적용)

  • Kim, Yongcheon;Choi, Jiyoung;Kwon, Daiyoung;Lee, Wongyu
    • Journal of The Korean Association of Information Education
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    • v.17 no.3
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    • pp.233-242
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    • 2013
  • "Problem-solving methods and procedures" sections in the 2009 revised informatics curriculum emphasized active use of algorithmic thinking to solve problems. And it is proposed to solve the various problems of real life using programming language for the implementation of the algorithm. Recently, various Educational Programming Language has been developed for elementary programming activity and many researches showed that students' cognitive burden was reduced in learning programming language with Educational Programming Languages. However implementation of the algorithm is difficult for novice programmer. For the reason, effective way is required for elementary students to connect design of the algorithm and implementation of the algorithm. Therefore, in this study propose the algorithm design worksheets that it is possible to create an algorithm to describe the content needed to implementation in programming education. And this study proved the effect of the algorithm design learning tools through experiment.

A Study on the Rectifying Inspection Plan & Life Test Sampling Plan Considering Cost (소비자 보호를 위한 선별형 샘플링 검사와 신뢰성 샘플링 검사의 최적설계에 관한 연구)

  • 강보철;조재립
    • Journal of Korean Society for Quality Management
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    • v.30 no.1
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    • pp.74-96
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    • 2002
  • The objectives of this study is to suggest the rectifying sampling inspection plan considering quality cost. Limiting quality level(LQL) plans(also called LTPD plans) and outgoing quality(OQ) plans are considered. The Hald's linear cost model is discussed with and without a beta prior for the distribution of the fraction of nonconforming items in a lot. It is assumed that the sampling inspection is error free. We consider the design of reliability acceptance sampling plan (RASP) for failure rate level qualification at selected confidence level. The lifetime distribution of products is assumed to be exponential. MIL-STD-690C and K C 6032 standards provide this procedures. But these procedures have some questions to apply in the field. The cost of test and confidence level(1-$\beta$ risk) are the problem between supplier and user. So, we suggest that the optimal life test sampling inspection plans using simple linear cost model considering product cost, capability of environment chamber, environmental test cost, and etc. Especially, we consider a reliability of lots that contain some nonconforming items. In this case we assumed that a nonconforming item fail after environmental life test. Finally, we develope the algorithm of the optimal sampling inspection plan based on minimum costs for rectifying inspection and RASP. And computer application programs are developed So, it is shown how the desired sampling plan can be easily found.

A Factor Analysis on the Degree of Importance of Professional Nursing for Advancing Nursing Image (간호이미지 개선을 위한 간호전문직의 중요도에 대한 일반인의 인식유형)

  • Oh Mi Jung
    • Journal of Korean Public Health Nursing
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    • v.14 no.1
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    • pp.80-99
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    • 2000
  • This study was designed to find the characteristics and patterns in subjectivity of an attitude on the degree of importance of professional nursing for advancing nursing image. Q-methodology was used as a research design and the research procedures were as follows. Q-sampling has been derived from the literature review and interview. Its credibility and validity were also tested by nursing professors. Total of 34 statements were selected. P-sampling has been drawn and 32 samples were selected. Based on 9 point scale. the selected respondents rated their operant definition on the degree of importance of professional nursing for advancing nursing image. The results of above procedures were analyzed by PCQ program. The attitude about the degree of importance of professional nursing for advancing nursing image were analyzed based on the typical array. extreme comments. and the demographic information of study subjects. The results revealed that there were four types of attitude about the degree of importance of professional nursing for advancing nursing image. The four types were named as follows; 1) The first type. agree of problem-solving perspectives. was consisted of 8 subjects. They emphasized that the nurse should solve a patient's problem promptly and precisely for advancing nursing image. 2) The second type. agree of kindness perspectives. was consisted of 5 subjects. They insisted that the nurse should be kind to patient and his family for advancing nursing image. 3) The third type. agree of love and service perspectives. was consisted of 4 subjects. They emphasized nursing spirit based on love and service for advancing nursing image. 4) The fourth type. agree of professional knowledge perspectives. was consisted of 6 subjects. They emphasized that the nurse should construct of professional nursing knowledge for advancing nursing image. As a result. this study discovered three types of the degree of importance of professional nursing for advancing nursing image. By identifying the nature of each of four types. this study can be useful to develop efficient strategies for advancing nursing image.

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A Study on the Analysis of Squeal Noise for Brake Design (저소음 브레이크 설계를 위한 스퀼 소음 해석기법 연구)

  • Kim, Chan-Jung;Lee, Dong-Won;Lee, Bong-Hyun;Na, Byung-Chul;Kim, Hyun-Chul;Kwon, Seong-Jin
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.16 no.8 s.113
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    • pp.830-839
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    • 2006
  • The phenomenon of squeal noise in the disk brake system has been, and still is, a. problem for the automotive industry. Extensive research has been carried out in an attempt to understand the mechanism that causes squeal noise and In developing design procedures to reduce squeal noise to make vehicles more comfortable. In this paper, the study on the analysis of squeal noise is performed by using computer aided engineering to design the anti-squeal noise disk brake system. The first part describes the chassis dynamometer and the testing procedure, and second part explains the finite element model and the complex eigenvalue analysis. Finally, it is shown that the proposed squeal noise analysis could be useful to investigate the design parameters that affect the squeal noise characteristics.

A Study on Public Design Project Management Process In Terms of Design Management (디자인경영 측면에서 본 공공디자인사업 관리프로세스에 관한 연구)

  • Park, Su-Kyoung;Moon, Jeong-Min
    • Korean Institute of Interior Design Journal
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    • v.21 no.6
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    • pp.71-78
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    • 2012
  • These days, design has been used a very useful means to achieve differentiated urban images and establish the identity of a city, and as an effort to specialize local industries through design, public design projects are competing one another. However, the projects have considerable negative effects because of diverse reasons such as unorganized procedures. For continuous and organized projects which meet demands of the interested persons of public design, reasonable design management should be introduced with a use of design as a strategic means of management Therefore, this study examined the concepts of design management and its meaning in space and analysed cases of implementing components for management of public design projects. It searched for the factors of design management indicating design-oriented management and presented a strategy model which complements design-oriented management. The results of the study are presented as follows: First, strategic implementing components needed for a space design management process were obtained. A design recognition process aimed at what space aims at and needed to identify active components such as physical and indigenous environment. A design inquiry process included problem solution considering characteristics of multi-dimensional space active components, design development considering behavioral functions of humans, checklists needed to complete design and necessary components to institutionalize design. For definition of project space, guideline projects of public design should be progressed in the same context as urban design, and developmental directions of public design needed design inquiry in terms of space to create various experiences in space.

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The relationship between a cognitive styles and a technological problem solving among the industrial high school students (공업계 고등학교 학생의 장독립·장의존 인지양식과 기술적 문제해결과의 관계)

  • Lee, Chang-Hoon;Kim, Ki-Soo
    • 대한공업교육학회지
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    • v.30 no.1
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    • pp.46-55
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    • 2005
  • The purpose of this study is to contemplate the relationship between a cognitive styles(field-independence/dependence, Fl/D)and a technological problem solving(TPS) among the industrial high school students. When it comes to perception, remembrance and consideration, we all have our own individual and steady patterns. We call them cognitive styles. FI/D is one kind of cognitive styles and it is about how dependently we perceive the field which each object has. Custer(1995) presented the technological problem among problem solving existed in various types as organizing it with four conceptional frames, which are invention, design, trouble shooting and procedures. We tested 56students belong to B industrial high school in A city, Korea. We used Group Embedded Figures Test(GEFT) to experiment the FI/D cognitive styles. We also did the TPS test by using an appliance which a researcher has developed. The appliance was made according to the technological problem and its validity was justified by an expert. We came up with a correlation coefficient between the FI/D cognitive styles and TPS to figure out what kind of relationship those two variable factors have and how much they are correlated each other. The correlation coefficient turned out ".59" which means they have significant and positive correlation.To find out the TPS difference between FI group and FD group, we compared each group's TPS score. As a result of the analysis, the FI group's TPS score is significantly higher than FD group's one.