• Title/Summary/Keyword: 재료재단

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한국연구재단 출범과 기초연구사업 추진방향

  • Bae, Byeong-Su
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2009.05a
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    • pp.4.1-4.1
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    • 2009
  • 기존의 교욱과학기술부 연구관리전문기관인 한국과학재단, 한국학술진흥재단, 국제과학기술협력재단을 통합하여 한국연구재단이 새로이 출범하면서 기초연구사업이 개편되어 시행되고 있다. 올해 수립된 기초연구진흥 종합계획에 따르면 개인 기초연구비가 대폭 증대되면서 개인 기초연구비 수혜율이 2012년까지 60%로 확대할 계획이다. 정부의 기초연구진흥계획과 한국연구재단의 출범이 연구자에게 주는 의미를 설명하고 새로 개편된 기초연구사업의 내용과 변경된 관리 규정등에 대해서 소개하여서 연구자들의 기초연구사업에 대한 이해를 돕고자 한다.

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Composite Stock Cutting using Distributed Simulated Annealing (분산 시뮬레이티드 어닐링을 이용한 복합 재료 재단)

  • Hong, Chul-Eui
    • Journal of KIISE:Software and Applications
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    • v.29 no.1_2
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    • pp.20-29
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    • 2002
  • The composite stock cutting problem is to allocate rectangular and/or irregular patterns onto a large composite stock sheet of finite dimensions in such a way that the resulting scrap will be minimized. In this paper, the distributed simulated annealing with the new cost error tolerant spatial decomposition is applied to the composite stock cutting problem in MPI environments. The cost error tolerant scheme relaxes synchronization and chooses small perturbations on states asynchronously in a dynamically changed stream length to keep the convergence property of the sequential annealing. This paper proposes the efficient data structures for representation of patterns and their affinity relations and also shows how to determine move generations, annealing parameters, and a cost function. The spatial decomposition method is addressed in detail. This paper identifies that the final quality is not degraded with almost linear speedup. Composite stock shapes are not constrained to convex polygons or even regular shapes, but the rotations are only allowed to 2 or 4 due to its composite nature.

A Study on The Cutting Pattern Generation of Membrane Structures and The Loss-Ratio of Material (막 구조물의 재단도 작성과 막재의 손실률에 관한 연구)

  • Shon, Su-Deok;Jeong, Eul-Seok;Kim, Seung-Deog
    • Journal of Korean Association for Spatial Structures
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    • v.6 no.1 s.19
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    • pp.117-127
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    • 2006
  • Membrane structures, a kind of lightweight soft structural system, are used for spatial structures. The design procedure of membrane structures are needed to do shape finding, stress-deformation analysis and cutting pattern generation, because the material property has strong axial stiffness, but little bending stiffness. The problem of cooing pattern is highly varied in their size, curvature and material stiffness. So, the approximation inherent in cutting pattern generation methods is quite different. Therefore the ordinary computer software of structural analysis & design is not suitable for membrane structures. In this study, we develop the program for cooing pattern generation using geodesic line, and investigate the result of example's cooing pattern in detail.

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막구조의 설계.시공 및 유지보수

  • 박명현;박지원
    • Computational Structural Engineering
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    • v.4 no.3
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    • pp.23-26
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    • 1991
  • 본 고에서는 막구조의 설계, 시공, 유지관리에 대해 개략적으로 기술하였다. 막구조는 그 여러가지 특성이 아직 규명이 안된 부분이 많고 시공오차가 비교적 큰 편이므로 막 재료의 역학적, 재료적 특성에 대한 연구와 형상해석 모델의 공식화, 막재단의 컴퓨터화가 필요하며 초기장력 도입에 따른 시공과정의 해석이 더욱 필요하다. 따라서 설계, 형상해석, 재단에서 시공 및 유지관리에 이르는 일괄적인 System의 개발이 시급하다 하겠다.

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Analysis and Classification of Acoustic Emission Signals During Wood Drying (목재 건조 중 발생하는 음향방출 신호의 해석 및 분류)

  • 김기복;강호양
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 2003.07a
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    • pp.469-477
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    • 2003
  • 삼림에서 벌채된 목재는 대부분 건조공정을 거쳐 산업용 재료가 되므로 건조정도에 따라 목질 재료의 품질이 결정된다. 목재에 포함된 과도한 수분을 제거하여 운송비용을 줄일 수 있으며 목재를 적절하게 건조하게 되면 목재 사용 중에 발생할 수 있는 수축 및 팽윤을 제한할 수 있을 뿐만 아니라 건조과정을 통해 비틀림, 갈라짐, 할열 등과 같은 결함의 발생을 크게 줄일 수 있다. 또한 건조된 목재는 생재에 비해 기계 가공이 보다 용이하기 때문에 정확한 치수로 재단이 가능하며, 각각의 부품으로 재단한 부재를 못이나 나사못, 볼트, 접착제 등을 사용하여 견고하게 짜 맞출 수 있다. 그리고 도장성능이 향상되어 기능성을 증진시킬 수 있으며, 건조 후의 방부처리를 통해 장기간의 사용이 가능하다. (중략)

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A Study on the Form Finding and Optimal Cutting Pattern Analysis Technique of Membrane Structures (막구조물의 형상탐색 및 최적재단도 해석기법에 관한 연구)

  • 서삼열
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.12 no.3
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    • pp.457-464
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    • 1999
  • The object of this study is form finding, stress-strain analysis and cutting pattern analysis of membrane structures under the following assumptions : (1) material is linearly elastic (2) stress state is plane stress. The cable and membrane structures undergo large deformation because of its highly flexibility, therefore, we must take account of its geometric nonlinearity. The analysis procedure is consisted of three steps considering geometric nonlinearity unlike any other structures. First step is the form finding analysis to determine the initial equilibrium shape. Second step is the stress-strain analysis to investigate the behaviors of structures under various external loads. Once a stationary shape has been fount a cutting pattern based on the form finding analysis may be generated for manufacturing procedure. In this paper, form finding, stress-strain analysis and cutting pattern analysis is carried out for applying to Seoguipo worldcup soccer stadium roof structures and optimal cutting pattern analysis technique is proposed.

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Experimental Study on Dynamic Characteristics of Structurally Tailored Isotropic Box Beams (강성재단 된 등방성 박스보의 동적 특성에 관한 실험적 연구)

  • Kim, Kyoung-Duck;Kim, Jun-Sik
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.37 no.5
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    • pp.641-648
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    • 2013
  • A beam is a major load-carrying member in many engineering structures. Beams with properly designed cross sections and stiffeners are required to enhance the structural properties. Such a design may cause various coupling behaviors, and therefore, an accurate analysis is essential for the proper design of beams. In this research, we manufactured box-beams with stiffeners, which mimic the out-of-plane composite bending-shear coupling behavior reported in literature. A modal test is carried out to obtain the dynamic characteristics, such as natural frequencies and mode shapes, of the box-beam. The obtained results are compared with those of 3D FEM, which confirm that the out-of-plane bending-shear coupling behavior reported in literature is possible. The coupling behavior can be controlled by the proper design of the stiffeners.

A Study on the Cutting Pattern Generation of the Membrane Structures Using Triangular Re-mesh (막 구조물의 삼각형 Re-mesh 패턴을 적용한 재단도 생성에 관한 연구)

  • Jeon, Jin-Hyung;Shon, Su-Deok;Jeong, Eul-Seok;Kim, Seung-Deog
    • Journal of Korean Association for Spatial Structures
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    • v.7 no.3 s.25
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    • pp.153-165
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    • 2007
  • Flexible structure uses a material with strong axial stiffness and small bending stiffness as its major structural material so it is very sensitive to initial stiffness. Therefore, the self-formation process which accomplishes a form in the natural world is grasped and it is as well investigated and classified the type of modeling techniques which are available to find the shapes of soft structures. Accordingly, for analysis and design of flexible structure, three-step analysis such as shape analysis, stress-deformation analysis, cutting pattern generation and constructional analysis is required unlike the existing stiff structure. In this study, suggest that minimize the error of side curvatures by the triangle Re-mesh pattern and draw the cutting pattern generation.

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