• 제목/요약/키워드: Computer Algebra System

검색결과 59건 처리시간 0.032초

반해석적 방법에 의한 작은 변위를 가지는 얇은판의 자유진동해석 (Free Vibration of a Thin Plate with Small Deflections by Semi-Analytical Approach)

  • 최덕기
    • 대한기계학회논문집
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    • 제18권8호
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    • pp.1967-1973
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    • 1994
  • The free vibration of a thin plate with three different boundary conditions is discussed in this paper. A semi-analytical approach to the plate problems has been exploited using computer algebra system(CAS). The approximate solutions are assumed as algebraic polynomials that satisfy the appropriate boundary conditions. In order to solve problems, Galerkin method is used, which is known as an ineffective tool for practical engineering problems, being involved with a large number of multiple integration and differentiation. All the admissible functions used in this paper are generated automatically by CAS otherwise a tedious algebraic manipulations should be done by hand. One, six and fifteen-term solutions in terms of frequency parameters are presented and compared with exact solutions. Even using one-term solution, the comparison with existing data shows good agreement and accuracy of the present method.

A High Quality Mesh Generation with Automatic Differentiation for Surfaces Defined by Hamiltonian Lie Algebra

  • Sagara, Naoya;Makino, Mitsunori
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2002년도 ITC-CSCC -2
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    • pp.1141-1144
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    • 2002
  • The research on computer graphics(CG) has been actively studied and developed. Namely, many surface/solid models have been proposed in the field of computer aided geometric design as well as the one of CG. Since it is difficult to visualize the complex shape exactly, an approximation by generating a set of meshes is usually used. Therefore it is important to guarantee the quality of the approximation in consideration of the computational cost. In this paper, a mesh generation algorithm will be proposed for a surface defined by Lie algebra. The proposed algorithm considers the quality in the meaning of validation of invariants obtained by the mesh, using automatic differentiation.

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On the Education of Talented Children for the Creativity Development by Using CAS

  • Takahashi, Tadashi
    • 한국수학교육학회지시리즈D:수학교육연구
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    • 제13권1호
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    • pp.1-4
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    • 2009
  • We are considering the discovery and the promotion of the talent from the viewpoint of education of talented children. The education that develops the talent is from "Individual needs for all children." Computer Algebra System (CAS) can be used as a new possibility in the education that develops the talent. We will need to take advantage of the research results from cognitive science. In order to fully utilize CASs in education, teaching methods that are based on cognitive science will be needed, and these are clearly different from those used in paper and pencil teaching.

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A High Quality Mesh Generation for a Surface defined by Linear tie Algebra

  • Sano, Hiroyasu;Makino, Mitsunori
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2000년도 ITC-CSCC -2
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    • pp.1103-1106
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    • 2000
  • Recently, the research on computer graphics (CG) has been actively studied and developed. Namely, many surface/solid models have been proposed in the field of computer aided geometric design as well as the one of CG. Since it is difficult to visualize the complex shape exactly, an approximation by generating a set of meshes is usually used. Therefore it is important to guarantee the quality of the approximation in consideration of the computational cost. In this paper, a mesh generation algorithm will be proposed for a surface defined by linear tie algebra The proposed algorithm which considers the quality in the meaning of validation of invariants obtained by the mesh.

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재귀적 패턴과 거북 마이크로월드 설계 (Designing a Microworld for Recursive Pasterns and Algebra)

  • 김화경
    • 한국수학교육학회지시리즈A:수학교육
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    • 제45권2호
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    • pp.165-176
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    • 2006
  • In this paper, we consider changes of algebra strands around the world. And we suggest needs of designing new computer environment where we make and manipulate geometric recursive patterns. For this purpose, we first consider relations among symbols, meanings and patterns. And we also consider Logo environment and characterize algebraic features. Then we introduce L-system which is considered as action letters and subgroup of turtle group. There are needs to be improved since there exists some ambiguity between sign and action. Based on needs of improving the previous L-system, we suggest new commands in JavaMAL microworld. So we design a microworld for recursive patterns and consider meanings of letters in new environments. Finally, we consider the method to integrate L-system and other existing microworlds, such as Logo and DGS. Specially, combining Logo and DGS, we consider the movement of such tiles and folding nets by L-system commands. And we discuss possible benefits in this environment.

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직교함수를 이용한 시스템의 제어 (System Control Using Orthogonal Function)

  • 안두수
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 하계학술대회 논문집 B
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    • pp.468-470
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    • 1998
  • We have studied system identification model reduction method, optimal control by orthogonal functions. This paper presents the easy method that solves algebra equations instead of differential equations using Walsh, Haar, Block pulse function of orthogonal functions in state equation. The proposed algorithm is verified through some examples.

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Investigation of the effect of shell plan-form dimensions on mode-shapes of the laminated composite cylindrical shallow shells using SDSST and FEM

  • Dogan, Ali;Arslan, H. Murat
    • Steel and Composite Structures
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    • 제12권4호
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    • pp.303-324
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    • 2012
  • This paper presents the mode-shape analysis of the cross-ply laminated composite cylindrical shallow shells. First, the kinematic relations of strains and deformation are given. Then, using Hamilton's principle, governing differential equations are developed for a general curved shell. Finally, the stress-strain relation for the laminated, cross-ply composite shells are obtained. By using some simplifications and assuming Fourier series as a displacement field, the governed differential equations are solved by the matrix algebra for shallow shells. Employing the computer algebra system called MATHEMATICA; a computer program has been prepared for the solution. The results obtained by this solution are compared with the results obtained by (ANSYS and SAP2000) programs, in order to verify the accuracy and reliability of the solution presented.

CAS IMPLEMENTATION OF RECURSIVE STRUCTURE IN A SPANNING TREE

  • Song, Kee-Hong
    • East Asian mathematical journal
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    • 제21권2호
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    • pp.249-260
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    • 2005
  • Experimentation using computer plays an important part in education and research in graph theory. The purpose of this paper is to develop the CAS techniques for the hands-on approach in graph theory specifically on the topic of constructing the spanning tree. This paper discusses the advantages of CAS as the software system for doing graph theory and introduces the software solutions integrating multimedia user interface developed by the author, which extend the functionality of the existing CAS-based graph theory software package.

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SCAM 기상모델의 성능향상을 위한 LAPACK BLAS 라이브러리의 활용 (Performance Improvements of SCAM Climate Model using LAPACK BLAS Library)

  • 신대영;조예린;정성욱
    • 한국정보전자통신기술학회논문지
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    • 제16권1호
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    • pp.33-40
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    • 2023
  • 슈퍼 컴퓨팅 기술 및 하드웨어 기술의 발달로 수치 연산 방식 또한 고도화되고 있다. 그에 따라 이전 대비 향상된 기상 예측 또한 가능해진다. 본 논문에서는 SCAM(Single-Columns Atmospheric Model, CESM(Community Earth System Model)을 간소화 한 버전)에 포함되어 있으며 대기 연산을 수행하는 적운 모수화 코드, Unicon(A Unified Convection Scheme)의 성능을 향상하기 위하여 소스 코드 내의 선형대수 수치적 연산 부분에 고밀도 선형대수 연산을 위한 라이브러리인 LAPACK(Linear Algebra PACKage) BLAS(Basic Linear Algebra Subprograms)의 level1 함수를 적용할 것을 제안한다. 이를 분석하기 위하여 SCAM의 전체적인 실행 구조도를 제시하고 해당 실행환경에서 테스트를 진행하였다. 기존 소스 코드 대비 SCOPY 함수는 0.4053%, DSCAL 함수는 0.7812%, DDOT 함수는 0.0469%의 성능 향상을 이끌어 내었으며 이를 모두 적용한 결과 기존 소스 코드 대비 0.8537%의 성능 향상을 보였다. 이는 본 논문에서 제안한 고밀도 선형대수 연산을 위한 라이브러리인 LAPACK BLAS 적용 방법이 동일한 CPU 환경에서 추가적인 하드웨어의 개입 없이 성능을 향상시킬 수 있음을 의미한다.