• Title/Summary/Keyword: Lanczos method

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Improved Lanczos Method for the Eigenvalue Analysis of Structures (구조물의 고유치 해석을 위한 개선된 Lanczos 방법)

  • 김병완;김운학;이인원
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2002.04a
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    • pp.133-140
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    • 2002
  • This paper investigates the applicability of the modified Lanczos method using the power technique, which was developed in the field of quantum physics, to the eigenproblem in the field of engineering mechanics by introducing matrix-powered Lanczos recursion and numerically evaluating the suitable power value. The matrix-powered Lanczos method has better convergence and less operation count than the conventional Lanczos method. By analyzing four numerical examples, the effectiveness of the matrix-powered Lanczos method is verified and the appropriate matrix power is also recommended.

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Efficient Vector Superposition Method for Dynamic Analysis of Structures (구조물의 동적해석을 위한 효율적인 벡터중첩법)

  • 김병완;정형조;김운학;이인원
    • Journal of the Earthquake Engineering Society of Korea
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    • v.7 no.3
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    • pp.39-45
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    • 2003
  • Modified Lanczos vector superposition method is proposed for efficient dynamic analysis of structures, The proposed method is based on the modified Lanczos algorithm that generates stiffness-orthonormal Lanczos vectors. The proposed Lanczos vector superposition method has the same accuracy and efficiency as the conventional Lonczos vector superposition method in the analysis of structures under single input loads. On the other hand, the proposed method is more efficient than the conventional method in the analysis of structures under multi-input loads. The effectiveness of the proposed method is verified by analyzing two numerical examples.

Efficient Scientific Computation on WP Parallel Computer (MP 병렬컴퓨터에서 효과적인 과학계산의 수행)

  • 김선경
    • Journal of Korea Society of Industrial Information Systems
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    • v.8 no.4
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    • pp.26-30
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    • 2003
  • The Lanczos algorithm is the most commonly used in approximating a small number of extreme eigenvalues for symmetric large sparse matrices. Global communications in MP(Message Passing) parallel computer decrease the computation speed. In this paper, we introduce the s-step Lanczos method, and s-step method generates reduction matrices which are similar to reduction matrices generated by the standard Lanczos method. One iteration of the s-step Lanczos algorithm corresponds to s iterations of the standard Lanczos algorithm. The s-step method has the minimized global communication and has the superior parallel properties to the standard method. These algorithms are implemented on Cray T3E and performance results are presented.

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A PROJECTION ALGORITHM FOR SYMMETRIC EIGENVALUE PROBLEMS

  • PARK, PIL SEONG
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.3 no.2
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    • pp.5-16
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    • 1999
  • We introduce a new projector for accelerating convergence of a symmetric eigenvalue problem Ax = x, and devise a power/Lanczos hybrid algorithm. Acceleration can be achieved by removing the hard-to-annihilate nonsolution eigencomponents corresponding to the widespread eigenvalues with modulus close to 1, by estimating them accurately using the Lanczos method. However, the additional Lanczos results can be obtained without expensive matrix-vector multiplications but a very small amount of extra work, by utilizing simple power-Lanczos interconversion algorithms suggested. Numerical experiments are given at the end.

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Dynamic Analysis of Structures by Superposition of Modified Lanczos Vectors (수정된 Lanczos 벡터의 중첩을 통한 구조물의 동적해석)

  • Kim, Byoung-Wan;Jung, Hyung-Jo;Kim, Woon-Hak;Lee, In-Won
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2003.04a
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    • pp.11-18
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    • 2003
  • This paper proposes modified Lanczos vector superposition method for efficient dynamic analysis of structures. Proposed method is based on the modified Lanczos algorithm that generates stiffness-orthonormal Lanczos vectors. Proposed method has better computing efficiency than the conventional Lanczos vector superposition method in the analysis of multi-input-loaded structures. The efficiency of proposed method is verified through numerical examples. Comparison with other vector superposition methods is also presented through numerical examples.

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Eigensolution Method for Structures Using Accelerated Lanczos Algorithm (가속화된 Lanczos 알고리즘을 이용한 구조물의 고유치 해법)

  • Kim, Byoung-Wan;Oh, Ju-Won;Lee, In-Won
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2002.09a
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    • pp.364-370
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    • 2002
  • 본 논문에서는 양자물리학 분야에서 Lanczos 방법의 수렴을 가속화하기 위해 개발된 바 있는 행렬의 거듭제곱 기법을 동역학 분야의 Lanczos 순환식에 도입함으로써 구조물의 고유치 해석의 효율성을 향상시켰다 행렬의 거듭제곱 기법을 도입한 Lanczos 방법이 기존의 방법보다 수렴성이 더욱 우수하다. 수치예제를 통해 행렬의 거듭제곱 기법을 도입한 Lanczos 방법의 효율성을 검증하였으며 제안방법을 통한 고유치 해석에 있어서 가장 적합한 거듭제곱값을 제시하였다.

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Dynamic Analysis of Structures by Component Mode Method using Ritz-Lanczos Algorithm (Ritz-Lanczos알고리즘을 이용한 Component mode Method에 의한 구조물의 동적 해석)

  • 심재수
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 1997.10a
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    • pp.151-158
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    • 1997
  • The main concern of numerical dynamic analysis of large structures is to find an acceptable solution with fewer mode shapes and less computational efforts. component mode method utilizes substructure technique to reduce the degrss of freedom but have a disadvantage to not consider the dynamic characteristics of loads. Ritz Vector method consider the load characteristics but requires many integrations and errors are accumulated. In this study, to prove the effectiveness of component mode method, Lanczos algorithm are introduced. To prove the effectiveness of this method, example structures areanalyzed and the results are compared with SAP90.

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Dynamic Analysis of Large Structures by Component Mode Method using Lanczos Algorithm and Ritz Vector (Lanczos알고리즘과 Ritz Vector를 이용한 Component Mode Method에 의한 거대구조물의 동적해석)

  • 심재수;황의승;박태현
    • Computational Structural Engineering
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    • v.9 no.2
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    • pp.115-120
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    • 1996
  • The main concern of numerical dynamic analysis of large structures is to find an acceptable solution with fewer mode shapes and less computational efforts. Component mode method utilizes substructure technique to reduce the degree of freedom but have a disadvantage to not consider the dynamic characteristics of loads. Ritz Vector method consider the load characteristics but requires many integrations and errors are accumulated. In this study, to improve the effectiveness of component mode method, Lanczos algorithm is introduced. To prove the effectiveness of this method, example structure are analyzed and the results are compared with SAP90.

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Nonlinear Transient Heat Transfer Analysis Based on LANCZOS Coordinates (LANCZOS 알고리즘에 기초한 비선형 트랜지언트 열전달 해석)

  • Im, Chang Kyun;Chang, Sung Pil
    • Journal of Korean Society of Steel Construction
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    • v.10 no.2 s.35
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    • pp.317-326
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    • 1998
  • This paper describes a reduced finite element formulation for nonlinear transient heat transfer analysis based on Lanczos Algorithm. In the proposed reduced formulation all material nonlinearities of irradiation boundary element are included using the pseudo force method and numerical time integration of the reduced formulation is conducted by Galerkin method. The results of numerical examples demonstrate the applicability and the accuracy of the proposed method for the nonlinear transient heat transfer analysis.

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THE INDEFINITE LANCZOS J-BIOTHOGONALIZATION ALGORITHM FOR SOLVING LARGE NON-J-SYMMETRIC LINEAR SYSTEMS

  • KAMALVAND, MOJTABA GHASEMI;ASIL, KOBRA NIAZI
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.24 no.4
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    • pp.375-385
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    • 2020
  • In this paper, a special indefinite inner product, named hyperbolic scalar product, is used and all acquired results have been raised and proved with the proviso that the space is equipped with this indefinite scalar product. The main objective is to be introduced and applied an indefinite oblique projection method, called Indefinite Lanczos J-biorthogonalizatiom process, which in addition to building a pair of J-biorthogonal bases for two used Krylov subspaces, leads to the introduction of a process for solving large non-J-symmetric linear systems, i.e., Indefinite two-sided Lanczos Algorithm for Linear systems.