• 제목/요약/키워드: Problem-oriented

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Development of a Multi-body Dynamics Analysis System Using the Object-Oriented Concept (객체지향 개념을 이용한 다물체 동역학 해석 시스템 개발)

  • 한형석;이재경;서종휘;송현석;박태원
    • Journal of the Korean Society for Precision Engineering
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    • 제20권8호
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    • pp.115-125
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    • 2003
  • To analyze the applications of all types of mechanical systems, general purpose analysis programs have been developed and commercialized. However, it is customary to develop and use customized programs even though they sometimes require more work than a general purpose program. A customized program is simplified to adapt to a particular application from the beginning, is designed for small computers, and developed with hardware-in-the-loop in mind so it can be applied effectively. By adding design knowledge and bundling know-how to an analysis program, analysis time can be reduced. And because an analysis has to work in conjunction with other analysis programs, a proprietary program that the user can easily modify can be useful. In this thesis, a multi-body dynamics analysis system is presented using one of the most useful programming techniques, object-oriented concept. The object-oriented concept defines a problem from the physical world as an abstract object, an abstract model. The object becomes encapsulated with the data and method. Simulation is performed using the object's interface. It is then possible for the user and the developer to modify and upgrade the program without having particular knowledge of the analysis program. The method presented in this thesis has the following advantages. Since the mechanical components of the multi-body system converts independent modeling into a class, the modification, exchange, distribution, and reuse of elements are increased. It becomes easier to employ a new analysis method and interface with other S/W and H/W systems. To employ a new analysis method, there is no need to modify elements of the main solver and the Library. In addition, information can be communicated to each object through messaging. It makes the modeling of new elements easier using inheritance. When developing a S/W for the computer simulation of physical system, it is reasonable to use object-oriented modeling. Also, for multi-body dynamics analysis, it is possible to develop a solver that is user-oriented.

Creative Problem Solving Styles, Conflict Management Types and Team Performance in the Cooperative Learning of Engineering College Students (공대생들의 협동학습에서 창의적 문제해결스타일 및 갈등관리 유형과 팀 수행)

  • Ahn, Jeong-Ho;Lim, Jee-Young
    • Journal of Engineering Education Research
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    • 제14권1호
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    • pp.40-45
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    • 2011
  • This study was conducted to compare the creative problem solving styles and conflict management types between engineering college students with high and low team performance records. Most students with high team performance records preferredDeveloper style(76.7%) and Task-oriented style(65.1%), whereas most students with low team performance records preferred Explorer style(72.2%) and Person-oriented style(86.1%). Results of the comparison of conflict management types revealed that most students with high team performance records belonged to a competitive logic type(22.8%) and an accommodative compromise type(17.7%), while most students with low team performance records belonged to an accommodative compromise type(20.3%) and a permissive resignation type(12.7%). It would be useful to provide the engineering students with the specialized program to complement their problem solving styles and conflict management types.

Design of the Mathematics Curriculum through Mathematical Modelling (수학적 모델링을 통한 교육과정의 구성원리)

  • 신현성
    • Journal of the Korean School Mathematics Society
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    • 제4권2호
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    • pp.27-32
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    • 2001
  • The paper describes some principles how we design the mathematics curriculum through mathematical Modelling. since the motivation for modelling is that it give us a cheap and rapid method of answering illposed problem concerning the real world situations. The experiment was focussed on the possibility that they can involved in modelling problem sets and carry modelling process. The main principles could be described as follows. principle 1. we as a teacher should introduce the modelling problems which have many constraints at the begining situation, but later eliminate those constraints possibly. principle 2. we should avoid the modelling real situations which contain the huge data collection in the classroom, but those could be involved in the mathematics club and job oriented problem solving. principle 3. Analysis of modelling situations should be much emphasized in those process of mathematics curriculum principle 4. As a matter of decision, the teachers should have their own activities that do mathematics curriculum free. principle 5. New strategies appropriate in solving modelling problem could be developed, so that these could contain those of polya's heusistics

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A New Approach for Resource Allocation in Project Scheduling with Variable-Duration Activities

  • Kim, Soo-Young;Leachman, Robert C.
    • Journal of the Korean Operations Research and Management Science Society
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    • 제19권3호
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    • pp.139-149
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    • 1994
  • In many project-oriented production systems, e. g., shipyards or large-scale steel products manufacturing, resource loading by an activity is flexible, and the activity duration is a function of resource allocation. For example, if one doubles the size of the crew assigned to perform an activity, it may be feasible to complete the activity in half the duration. Such flexibility has been modeled by Weglarz [13] and by Leachman, Dincerler, and Kim [7[ in extended formulations of the resource-constrained poject scheduling problem. This paper presents a new algorithmic approach to the problem that combines the ideas proposed by the aforementioned authors. The method we propose involves a two-step approach : (1) solve the resource-constrained scheduling problem using a heuristic, and (2) using this schedule as an initial feasible solution, find improved resource allocations by solving a linear programming model. We provide computational results indicating the superiority of this approach to previous methodology for the resource-constrained scheduling problem. Extensions to the model to admit overlap relationship of the activities also are presented.

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A new approach for resource allocation in project scheduling with variable-duration activities

  • 김수영;제진권;이상우
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 대한산업공학회/한국경영과학회 1994년도 춘계공동학술대회논문집; 창원대학교; 08월 09일 Apr. 1994
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    • pp.410-420
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    • 1994
  • In many project-oriented production systems, e.g., shipyards or large-scale steel products manufacturing, resource loading by an activity is flexible, and the activity duration is a function of resource allocation. For example, if one doubles the size of the crew assigned to perform an activity, it may be feasible to complete the activity in half the duration. Such flexibility has been modeled by Weglarz [131 and by Leachman, Dincerler, and Kim [7] in extended formulations of the resource-constrained project scheduling problem. This paper presents a new algorithmic approach to the problem that combines the ideas proposed by the aforementioned authors. The method we propose involves a two-step approach: (1) solve the resource-constrained scheduling problem using a heuristic, and (2) using this schedule as an initial feasible solution, find improved resource allocations by solving a linear programming model. We provide computational results indicating the superiority of this approach to previous methodology for the resource-constrained scheduling problem. Extensions to the model to admit overlap relationships of the activities also are presented.

Consumer Problem Perceived by Urban Low-Income Consumers and the Related Factors (도시 저소득층의 소비자문제지각과 관련요인 연구)

  • 김성숙;이기춘
    • Journal of Families and Better Life
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    • 제7권2호
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    • pp.31-43
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    • 1989
  • The purposes of this study were to identify the overall levels of consumer problem, consumer competencies and purchase pattern of urban low-income consumers and to examine the factors affecting the consumer problem and the subareas-market environment problem(MEP) and transaction relation problem(TRP). The related factors, that is, independent variables were competencies-related factors(consumption-oriented attitude, attitude on consumerism, consumer knowledge), purchase pattern-related factors (search pattern, credit pattern, peddler pattern) and socio-demorgraphic factors(age, educational level, family size). For this purpose, a survey was conducted by interview using questionaires on 198 homemakers that lived in the poor areas of Seoul. Statistics used for data analysis were Frequency Distribution, Percentile, Mean, Pearson's Correlation, One-way ANOVA, Scheffe-test, Breakdown and Multiple Classification Analysis. Major findings were as follows: 1) In the level of consum r problem were in the middle level and the level of MEP were higher than that of TRP. The attitude on consumption-orientation was so negative, while attitude on consumerism was positive. The level of consumer knowledge was in the middle level. The urban low-income consumers searched a little and depended on credit and peddler in the low level. 2) Consumer problem perceived by urban low-income consumers differed significantly according to attitude on consumerism, credit pattern, monthly charge of peddler purchase. The MEP depended on attitude on consumerism and monthly charge of peddler purchase, and the TRP was affected by credit pattern and attitude on consumerism. Resulting from MCA, the most influencial variable was attitude on consumerism and credit pattern in the consumer problem, and attitude on consumerism in the MEP, and credit pattenr in the TRP.

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Comparative Study on Self-Care Behavior, Diabetes-related Stress, and Stress Coping among Good, Inadequate, and Poor Glycemic Control Groups (혈당 조절 양호, 불충분, 불량 군 간의 자가간호행위, 당뇨관련 스트레스, 스트레스 대처의 비교)

  • Kang, Hye-Yeon;Gu, Mee-Ock
    • Journal of Korean Academy of Fundamentals of Nursing
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    • 제19권2호
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    • pp.168-178
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    • 2012
  • Purpose: The purpose of this study was to compare self-care behavior, diabetes-related stress and stress coping style among 3 blood glucose control groups (good, inadequate, and poor blood glucose control groups). Methods: Participants were 102 type 2 diabetic patients (good group: 41, inadequate group: 31, poor group: 30). Data were collected from Feb 19 to Mar 24, 2010 and were analyzed using Chi-square, Fisher's exact test and ANCOVA with SPSS/WIN 12.0. Results: Using ANCOVA with frequency of admission, and illness duration as covariates, significant differences were found among the 3 groups in self-care behavior (total score) and the exercise subscale. Using ANCOVA significant differences were found among 3 groups in diabetes-related stress (total score), emotional burden subscale and regimen distress subscale. Using ANCOVA no difference in stress coping was found among the 3 groups, but there was a significant difference in the problem-oriented coping subscale. Conclusions: Self-care behavior, diabetes-related stress, and stress coping style are factors influencing blood glucose control. The results of this study suggest that for improving blood glucose control, self care education program focused on diet and exercise in addition to stress management program for promoting problem oriented coping capability are recommended.

Factors Influencing Headache in Children (아동의 두통 관련 요인)

  • Hong, Yeon-Ran
    • Journal of Korean Academy of Nursing
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    • 제35권6호
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    • pp.1183-1189
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    • 2005
  • Objectives : This descriptive study was conducted to examine the degree of stress, coping styles, communication with the mother and depression between headache-suffering children and headache-free children and to explore predicted factors for headache occurrence in children. Method : The subjects of this study consisted of 196 headache-free children and 107 headache-suffering children. They were 4th-6th graders of an elementary school in T city. The instruments in this study were David's stressor of children, Lazarus & Folkman's Stress Coping Style, PACI(Parent-Adolescent Communication Inventory) by Barnes & Olsen and Kovac's CDI (Children's depression inventory). Data were collected from May 2 to July 16, 2004. Results : Total stress(t=-3.76, p=.035), school stress(t=-3.02, p=.001), mass media stress(t=-1.39, p=.029) and depression(t=7.62, p=.001) in headache-suffering children were significantly higher than those of headache-free children. Problem-oriented coping skills (t=1.23, p=.023), and the score of communication with the mother(t=2.32, p=.012) in headache-suffering children were lower than those of headache-free children. Logistic regression analysis (stepwise) showed that the most powerful predictor was stressors in school, followed by depression, stressors in mass media and communication with the mother. Conclusions: This study revealed that important factors such as the degree of school stress, depression, the degree of mass media stress, communication with the mother and problem-oriented coping skills should be controlled for reducing of headaches in children.

Symptoms, Depression, and Coping Behaviors of University Students (대학생의 자각증상과 우울 및 스트레스 대처행동에 관계)

  • 최미경
    • Journal of Korean Academy of Nursing
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    • 제33권3호
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    • pp.433-439
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    • 2003
  • Purpose: The purpose of this study was to examine the relationship among subjective symptoms, depression, and stress coping behavior of university students. Method: The survey was carried out on a convenience sample of 298 university students. The questionnaire consisted of each scale for symptoms, depression, and stress coping behaviors. Data analysis procedure included the factor analysis for stress coping behaviors, and the correlation analysis describing a relationship among symptoms, depression, and stress coping behaviors. Result: There were significant correlations between depression and the three types of symptoms: general, psychological, and somatic symptom. Subjects using the negative-emotional-response coping and the self-control coping showed a more severe depression, and those using the problem-solvingㆍreappraisal coping and the positive-emotional-response coping showed a milder depression. Subjects using the negative-emotional-response coping complained of all 3 types of symptoms severely, and those using the positive-emotional-response coping complained of general symptoms mildly. Of five stress coping methods, the negative-emotional-response and the positive-emotional-response coping methods were related to both symptoms and depression significantly. Conclusion: This study suggests that the emotional-oriented coping method has more important role for university student’s depression and their subjective symptoms than the problem-oriented coping or social supports seeking coping. Further study needs to be conducted to help students effective coping mechanism for good mental health. Also it is necessary for university students to recognize that their symptoms are associated with depression.

Web based General Partial Differential Equation Solver using Multidimensional Finite Element Method - I. Model Development - (다차원 유한요소법을 이용한 웹 기반의 범용적 편미분 방정식 해석 모형의 개발 및 적용 - I. 모형의 개발 -)

  • Kim, Joon-Hyun;Han, Young-Han
    • Journal of Environmental Impact Assessment
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    • 제10권4호
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    • pp.319-326
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    • 2001
  • This study is aimed at the development of a comprehensive web-based partial differential equation solver (WPDES) using multidimensional finite element method, which can be operated on the basis of world wide web. Overall issues of engineering and environmental information management and facility control could be implemented using this solver. This paper describes the development technique of the model, which is first part on development of partial differential equation solver. Conventional commercial general solver of computational fluid dynamics problems were investigated. All the relevant environmental models were analyzed to develop integrated environmental management system using WPDES. The governing equations and the parameters of investigated models were analyzed and integrated. Several numerical modules were invented for each partial differential term in partial differential equation of many related modeling problems. Each module was coded in the fashion of object oriented method, and was combined independently for the overall governing equation. WPDES has unique characteristic, which can analyze the problem through the suitable combination of modules without development of additional models for each environment problem with different governing equation, main variables, and parameters.

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