• 제목/요약/키워드: problem solving

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소마큐브(Soma Cube) 활동에서 포함-배제 방법의 활용에 대한 연구 (A Study on The Application of Inclusion-Exclusion Method in Soma Cube Activity)

  • 심상길;황선욱
    • 한국수학교육학회지시리즈A:수학교육
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    • 제48권1호
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    • pp.33-45
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    • 2009
  • The purpose of this article is to study characteristics of Soma Cube in combinatorial-geometric point of view, and to present basic substances and direction for efficient Soma cube activities in school mathematics upon systematical analysis of methods of finding solutions using Inclusion-Exclusion Method. We can apply Inclusion-Exclusion Method to find all possible solutions in Soma Cube activities not as trial-and-error method but as analytical method. Because Inclusion-Exclusion Method can reduce the number of problem-solving variables by making high conjunction in the choice of pieces. Soma cube pieces can be sorted as 'flat' ones and 'non-flat' ones, which would be another effective method in the manipulation of Soma Cube pieces.

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LPG 액정분사 방식의 대형 엔진용 피스톤의 온도분포와 열응력 해석 (Temperature Distribution and Thermal Stress Analyses of a Large LPLi Engine Piston)

  • 임문혁;손재율;이부윤
    • Journal of Advanced Marine Engineering and Technology
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    • 제28권3호
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    • pp.538-550
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    • 2004
  • The convection heat transfer coefficients on the top surface of a large liquid petroleum liquid injection(LPLi) engine piston with the oil gallery are analyzed by solving an inverse thermal conduction problem. The heat transfer coefficients are numerically found so that the difference between analyzed temperatures from the finite element method and measured temperatures is minimized. Using the resulting heat transfer coefficients as the boundary condition, temperature of a large LPLi engine piston is analyzed. With varying cooling water temperature, temperature, stress, and thermal expansion of the piston are analyzed and evaluated.

손목오프셋을 갖는 6축 로봇을 위한 효과적인 역기구학 해 방법 (An Efficient Inverse Kinematics Solution Method for the 6 Axes Robot with Offest Wrist)

  • 범진환;임생기;손명현
    • 대한기계학회논문집
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    • 제18권6호
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    • pp.1421-1429
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    • 1994
  • An algorithm is developed for solving the inverse kinematic problem of a 6-degree-of-freedom robot with a wrist offset for which the closed form inverse solutions are not obtainable, but knowledge of one joint variable allows closed form solutions of the remaining joint variables. The algorithm does not require Forward Kinematics nor Jacobian but uses the implicit kinematic relationships between joint variables and the given hand position. An iterative back substitution method is used to solve the inversion and the optimal conditions of the convergence are incoporated. An example is given to illustrate the concepts, the solution procedure and its convergency.

쇼트피이닝재와 언피닝재의 피로균열진전거동 평가 (Evaluation on Fatigue Crack Propagation Behavior of The Shot-peened and un-peened Spring Steel)

  • 박경동;류찬욱
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2003년도 춘계학술대회
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    • pp.247-254
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    • 2003
  • The lightness of components required in automobile and machinery industry is requiring high strength of components. In particular manufacturing process and new materials development for solving the fatigue fracture problem attendant upon high strength of suspension of automobile are actively advanced. In this paper, the effect of compressive residual stress of spring steel(JISG SUP-9) by shot-peening on fatigue crack growth characteristics in high temperatures($100^{\circ}$, $150^{\circ}$, $180^{\circ}$) was investigated with considering fracture mechanics. So, we can obtain followings. (1)Compressive residual stress decreases in high temperature, that is, with increasing temperature. (2)The effect of compressive residual stress on fatigue crack growth behavior in high temperature increases below ${\Delta}K=17{\sim}19MPa$ (3)It was investigated by SEM that the constraint of compress residual stress for plastic zone of fatigue crack tip was decreased in high temperature as compared with room temperature.

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엇갈린 핀 배열을 갖는 평판 열교환기의 최적 설계 (Design Optimization of Plate Heat Exchanger with Staggered Pin Arrays)

  • 박경우;최동훈;이관수;장규호
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2003년도 춘계학술대회
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    • pp.1441-1446
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    • 2003
  • The design optimization of the plate heat exchanger with staggered pin arrays for a fixed volume is performed numerically. The flow and thermal fields are assumed to be a streamwise-periodic flow and heat transfer with constant wall temperature and they are solved by using the finite volume method. The optimization is carried out by using the sequential linear programming (SLP) method and the weighting method is used for solving the multi-objective problem. The results show that the optimal design variables for the weighting coefficient of 0.5 are as follows; S=6.497mm, P=5.496mm, $D_1=0.689mm$, and $D_2=2.396mm$. The Pareto optimal solutions are also presented.

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초등학교 통계 영역에서 NIE를 통한 학습이 학업성취에 미치는 효과 (The Effects of NIE on Statistics Learning of Elementary School)

  • 서지영;표용수
    • 한국학교수학회논문집
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    • 제13권4호
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    • pp.499-524
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    • 2010
  • 본 본문에서는 학생 스스로 활동을 통해 통계적 개념, 자료 분석력, 문제해결력 등을 기를 수 있는 NIE(Newspaper in Education)을 통한 학습을 초등수학 학습지도에 적용하여, NIE를 활용한 학습이 초등학생의 통계 영역 학업성취에 미치는 효과를 살펴보고, 보다 효율적인 초등수학 학습지도 방안을 찾아보고자 한다.

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암환자가족의 가족기능에 대한 조사연구 (A Study on the Family Functioning in the Family with the Cancer Patient)

  • 한숙정
    • 종양간호연구
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    • 제3권2호
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    • pp.155-163
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    • 2003
  • This study was designed to assess the level of family function between cancer patient's families and normal families, and to seek better quality family-Mcentered nursing care. The subjects for this study were 95 ca patient's families who were selected from th university hospitals and 95 normal families who selected from 1 university hospital. The instrument used for this study was McMaster Family Assessment Device (FAD) developed by Epstein, Baldwin and Bishop (1983). The scale consisted of 53 items covering 7 areas: 'problem solving', 'communication', 'roles', 'affective responsiveness', 'affective involvement', 'behavior control', and 'general functioning'. As for data analyses, descriptive statistics, ${\chi}^2-test$, t-test, ANOVA were adopted using SAS program. The result of this study was as follows: There there was no significant difference between cancer patient's family function and normal family function. Also there was no significant difference on cancer patient's family function with regard to family characteristics, disease's characteristics, and clinical stage of cancer.

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대칭형 다계층 공진화 알고리듬을 이용한 FMS 공정계획 (FMS process planning using a symmetric multi-layered coevolutionary algorithm)

  • 김재윤;김여근
    • 한국경영과학회:학술대회논문집
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    • 한국경영과학회/대한산업공학회 2003년도 춘계공동학술대회
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    • pp.1048-1055
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    • 2003
  • This paper proposes a new method of solving integrated problems that consist of several sub-problems in a symmetric multi-layered structure, and also demonstrate the applicability of the method. The proposed method is named Symmetric Multi-layered Coevolutionary Algorithm (SMCA). The SMCA imitates partly the natural process of endosymbiotic evolution, which is a special type of coevolution. The SMCA is applied to the process planning problem in flexible manufacturing system (FMS), taking account of the flexibility of machine, tool, process, and sequence. To do this, SMCA's components are studied and its strategies are developed to improve the performance. The proposed algorithm is compared with the existing ones in terms of solution quality. The experimental results confirm the effectiveness of our approach.

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모순분석을 이용한 대량맞춤에서의 제품 플랫폼 결정 및 적용사례

  • 김경희;박준영
    • 한국경영과학회:학술대회논문집
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    • 대한산업공학회/한국경영과학회 2006년도 춘계공동학술대회 논문집
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    • pp.320-327
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    • 2006
  • 다양한 고객의 니즈를 충족시키기 위해 등장한 Mass Customization은 과거 대량생산방식의 비용만큼 저렴한 비용으로 다양한 제품 및 서비스를 생산한다. 하지만 저비용과 제품의 다양성은 서로 상반되는 특성을 지니기 때문에 이를 해결할 수 있는 여러 표준화 방법들이 필요하다. 본 연구에서는 Mass Customization을 지원하는 부품 표준화 방법 중의 하나인 Product Platform을 결정하는 방법을 도출해보고자 한다. 특히 TRIZ(Theory of Inventive Problem Solving)의 모순분석을 활용하여 Product Platform을 구성하는 아이디어를 얻어 냈는데 그 과정을 통해 Platform, 한정된 자원이나 제한된 조건 안에서 최대한 많은 제품을 얻을 수 있도록 모형을 도출하였다. 또한 Design Structure Matrix를 통해 부품들의 연관성을 측정하여 주요 해결책을 보완함으로써 Product Platform 결정의 유연성을 증대시킬 수 있는 해결책을 제시하였다.

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독립좌표연성법을 이용한 원환판의 자유진동해석 (Free Vibration Analysis of an Annular Plate by the Independent Coordinate Coupling Method)

  • 허석;곽문규
    • 한국소음진동공학회논문집
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    • 제18권5호
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    • pp.564-571
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    • 2008
  • This paper is concerned with the free vibration analysis of an annular plate with boundary conditions of simply supported-free, clamped-free and free-free, respectively. Exact solutions for the natural frequency and mode of an annular plate can be obtained by solving the differential equation but other methods such as the Rayleigh-Ritz method and the finite element method can be also used. In this research, we applied the Independent Coordinate Coupling Method(ICCM) to the annular plate and prove that the ICCM can accurately predict the natural frequency and mode shape of the annular plate. The numerical results show that the ICCM can be used effectively for the free vibration problem of plate with a hole compared to the Rayleigh-Ritz method and the finite element method.