• 제목/요약/키워드: iterative method

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할선강성을 이용한 직접 비선형 스트럿-타이 모델 (Direct Nonlinear Strut-Tie Model Using Secant Stiffness)

  • 김윤곤;엄태성;박홍근
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2003년도 가을 학술발표회 논문집
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    • pp.384-387
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    • 2003
  • A new Direct Nonlinear Strut-Tie Model design method performing iterative calculations using secant stiffness was developed. Since basically the proposed design method uses elastic analysis, it has the advantages of convenience and stability in numerical analysis. At the same time, the proposed design method can accurately estimate the strength and ductility demands on the members because it analyzes the inelastic behavior of structure using iterative calculation. In the present study, the procedure of the proposed design method was established, and a computer program incorporating the proposed method was developed. The proposed design method, as an integrated method of analysis and design, can address the earthquake design strategy devised by the engineer, such as ductility limit on each member. Through iterative calculations on the structure preliminary designed with member sizes, the strength and ductility demands of each member can be estimated so that they satisfy the given design strategy, and as the result economical and safe design is achieved.

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경계요소법을 이용한 경계에 직교하는 삼차원 격자형성법 (Three-Dimensional Grid Generation Method for an Orthogonal Grid at the Boundary by Using Boundary Element Method)

  • 정희권;권장혁
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 1995년도 추계 학술대회논문집
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    • pp.82-89
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    • 1995
  • In the present paper, a method of nearly orthogonal grid generation in an arbitrary simply-connected 3D domain will be presented. The method is a new direct and non-iterative scheme based on the concept of the decomposition of the global orthogonal transformation into consecutive mapping of a conformal mapping and an auxiliary orthogonal mapping, which was suggested by King and Leal [4]. In our numerical scheme. Kang and Leal's method is extended from 2D problems to 3D problems while the advantage of the non-iterative algorithm is maintained. The essence of the present mapping method is that an iterative scheme can be avoided by introducing a preliminary step. This preliminary step corresponds to a conformal map and is based on the boundary element method(BEM). This scheme is applied to generate several nearly-orthogonal grid systems which are orthogonal at boundaries.

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Hybrid Linear Closed-Form Solution in Wireless Localization

  • Cho, Seong Yun
    • ETRI Journal
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    • 제37권3호
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    • pp.533-540
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    • 2015
  • In wireless localization, several linear closed-form solution (LCS) methods have been investigated as a direct result of the drawbacks that plague the existing iterative methods, such as the local minimum problem and heavy computational burden. Among the known LCS methods, both the direct solution method and the difference of squared range measurements method are considered in this paper. These LCS methods do not have any of the aforementioned problems that occur in the existing iterative methods. However, each LCS method does have its own individual error property. In this paper, a hybrid LCS method is presented to reduce these errors. The hybrid LCS method integrates the two aforementioned LCS methods by using two check points that give important information on the probability of occurrence of each LCS's individual error. The results of several Monte Carlo simulations show that the proposed method has a good performance. The solutions provided by the proposed method are accurate and reliable. The solutions do not have serious errors such as those that occur in the conventional standalone LCS and iterative methods.

A NON-OVERLAPPING DOMAIN DECOMPOSITION METHOD FOR A DISCONTINUOUS GALERKIN METHOD: A NUMERICAL STUDY

  • Eun-Hee Park
    • Korean Journal of Mathematics
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    • 제31권4호
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    • pp.419-431
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    • 2023
  • In this paper, we propose an iterative method for a symmetric interior penalty Galerkin method for heterogeneous elliptic problems. The iterative method consists mainly of two parts based on a non-overlapping domain decomposition approach. One is an intermediate preconditioner constructed by understanding the properties of the discontinuous finite element functions and the other is a preconditioning related to the dual-primal finite element tearing and interconnecting (FETI-DP) methodology. Numerical results for the proposed method are presented, which demonstrate the performance of the iterative method in terms of various parameters associated with the elliptic model problem, the finite element discretization, and non-overlapping subdomain decomposition.

쌍대반응표면최적화를 위한 반복적 선호도사후제시법 (An Iterative Posterior Preference Articulation Approach to Dual Response Surface Optimization)

  • 정인준
    • 품질경영학회지
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    • 제40권4호
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    • pp.481-496
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    • 2012
  • Purpose: This paper aims at improving inefficiency of an existing posterior preference articulation method proposed for dual response surface optimization. The method generates a set of non-dominated solutions and then allows a decision maker (DM) to select the best solution among them through an interval selection strategy. Methods: This paper proposes an iterative posterior preference articulation method, which repeatedly generates the predetermined number of non-dominated solutions in an interval which becomes gradually narrower over rounds. Results: The existing method generates a good number of non-dominated solutions not used in the DM's selection process, while the proposed method generates the minimal number of non-dominated solutions necessitated in the selection process. Conclusion: The proposed method enables a satisfactory compromise solution to be achieved with minimal cognitive burden of the DM as well as with light computation load in generating non-dominated solutions.

AN ITERATIVE METHOD FOR ORTHOGONAL PROJECTIONS OF GENERALIZED INVERSES

  • Srivastava, Shwetabh;Gupta, D.K.
    • Journal of applied mathematics & informatics
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    • 제32권1_2호
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    • pp.61-74
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    • 2014
  • This paper describes an iterative method for orthogonal projections $AA^+$ and $A^+A$ of an arbitrary matrix A, where $A^+$ represents the Moore-Penrose inverse. Convergence analysis along with the first and second order error estimates of the method are investigated. Three numerical examples are worked out to show the efficacy of our work. The first example is on a full rank matrix, whereas the other two are on full rank and rank deficient randomly generated matrices. The results obtained by the method are compared with those obtained by another iterative method. The performance measures in terms of mean CPU time (MCT) and the error bounds for computing orthogonal projections are listed in tables. If $Z_k$, k = 0,1,2,... represents the k-th iterate obtained by our method then the sequence of the traces {trace($Z_k$)} is a monotonically increasing sequence converging to the rank of (A). Also, the sequence of traces {trace($I-Z_k$)} is a monotonically decreasing sequence converging to the nullity of $A^*$.

반복계산에 의한 고유치 해석 알고리즘의 2차 뉴튼랩슨법으로의 정식화 (A Formulation of Iterative Eigenvalue Analysis Algorithm to the Second Order Newton Raphson Method)

  • 김덕영
    • 대한전기학회논문지:전력기술부문A
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    • 제51권3호
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    • pp.127-133
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    • 2002
  • This paper presents an efficient improvement of the iterative eigenvalue calculation method of the AESOPS algorithm. The intuitively and heuristically approximated iterative eigenvalue calculation method of the AESOPS algorithm is transformed to the Second Order Newton Raphson Method which is generally used in numerical analysis. The equations of second order partial differentiation of external torque, terminal and internal voltages are derived from the original AESOPS algorithm. Therefore only a few calculation steps are added to transform the intuitively and heuristically approximated AESOPS algorithm to the Second Order Newton Raphson Method, while the merits of original algorithm are still preserved.

구속 조건을 사용한 공액 경사법에 의한 정칙화 반복 복원 처리 (Regularized iterative image resotoration by using method of conjugate gradient with constrain)

  • 김승묵;홍성용;이태홍
    • 한국통신학회논문지
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    • 제22권9호
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    • pp.1985-1997
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    • 1997
  • 공액 경사법을 이용한 정칙화 반복 복원 방법에 관하여 논하였다. 기존의 반복 복원 방법에 비하여, 공액 경사법을 이용한 반복 복원 방법은 초선형적인 속도로 해에 수렴한다는 장점을 지닌다. 그러나, 이와 같은 성질로 인해 잡음과 흐려짐현상으로 훼손된 영상을 복원하는 과정에서 잡음의 증폭이나 파문현상과 같은 결합을 갖게된다. 본 논문은 구속 조건을 적용한 정칙화 공액 경사법을 제안한다. 정칙화 공액 경사법에 정칙화 구속 조건과 정칙화 변수를 적용함으로서, 영상에서 윤곽 부분의 평활화없이 파문 현상을 감소시킬 수 있을 뿐 아니라, 가산 잡음의 증폭을 억제할 수 있다는 장점을 지닌다. 실험 결과를 통하여 기존의 정칙화 반복 복원 방법에 비해 본 논문에서 제안한 방법이 수렴비에 우수함을 증명하였다.

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A computed torque method incorporating an iterative learning scheme

  • Nam, Kwanghee
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1989년도 한국자동제어학술회의논문집; Seoul, Korea; 27-28 Oct. 1989
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    • pp.1097-1112
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    • 1989
  • An iterative learning control scheme is incorporated to the computed torque method as a means to enhance the accuracy and the flexibility. A learning rule is constructed by utilizing a gradient descent algorithm and data compressing techniques are illustrated. Computer simulation results show a good performance of the scheme under a relatively high speed and a heavy payload condition.

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