• Title/Summary/Keyword: basis

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An Optimization of Air-Lubricated Slider Bearings Using the Reduced Basis Concept (축소기초모델개념을 이용한 공기윤활 슬라이더 베어링의 최적설계)

  • Yoon, Sang-Joon;Kim, Dong-In;Kang, Tae-Sik;Jeong, Tae-Gun;Choi, Dong-Hoon
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.27 no.3
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    • pp.343-348
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    • 2003
  • In this study, optimum designs of the air-bearing surface (ABS) are achieved using the reduced basis concept which can effectively reduce the number of design variables without cutting down on the design space. Even though the optimization method is easier and more applicable to handle than the trial-and-error method, its efficiency is largely dependent on the number of the design variables. Hence, the reduced basis concept is applied, by which the desired design can be defined as a linear combination of basis designs. The simulation results show the effectiveness of the proposed approach by obtaining the optimum solutions of the sliders whose target flying heights are 25, 20, and 15nm.

Radial basis collocation method for dynamic analysis of axially moving beams

  • Wang, Lihua;Chen, Jiun-Shyan;Hu, Hsin-Yun
    • Interaction and multiscale mechanics
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    • v.2 no.4
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    • pp.333-352
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    • 2009
  • We introduce a radial basis collocation method to solve axially moving beam problems which involve $2^{nd}$ order differentiation in time and $4^{th}$ order differentiation in space. The discrete equation is constructed based on the strong form of the governing equation. The employment of multiquadrics radial basis function allows approximation of higher order derivatives in the strong form. Unlike the other approximation functions used in the meshfree methods, such as the moving least-squares approximation, $4^{th}$ order derivative of multiquadrics radial basis function is straightforward. We also show that the standard weighted boundary collocation approach for imposition of boundary conditions in static problems yields significant errors in the transient problems. This inaccuracy in dynamic problems can be corrected by a statically condensed semi-discrete equation resulting from an exact imposition of boundary conditions. The effectiveness of this approach is examined in the numerical examples.

Effect of Changing the Basis in Genetic Algorithms Using Binary Encoding

  • Kim, Yong-Hyuk;Yoon, You-Rim
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.2 no.4
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    • pp.184-193
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    • 2008
  • We examine the performance of genetic algorithms using binary encoding, with respect to a change of basis. Changing the basis can result in a change in the linkage structure inherent in the fitness function. We test three simple functions with differing linkage strengths and analyze the results. Based on an empirical analysis, we show that a better basis results in a smoother fitness landscape, hence genetic algorithms based on the new encoding method provide better performance.

A study on constructing a good initial basis in the simplex method (단체법에서의 초기기저 구성에 관한 연구)

  • 서용원;김우제;박순달
    • Korean Management Science Review
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    • v.13 no.3
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    • pp.105-113
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    • 1996
  • Constructing an initial basis is an important process in the simplex method. An initial basis greatly affects the number of iterations of iterations and the execution time in the simplex method. The purpose of this paper is to construct a good initial basis. First, to avoid linear dependency among the chosen columns, an enhanced Gaussian elimination method and a method using non-duplicated nonzero elements are developed. Second, for an order to choose variables, the sparsity of the column is used. Experimenal results show that the proposed method can reduce the number of iterations and the execution time compared with Bixby's method by 12%.

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BASIS FOR ALMOST LINEAR SPACES

  • Lee, Sang-Han
    • The Pure and Applied Mathematics
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    • v.2 no.1
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    • pp.43-51
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    • 1995
  • In this paper, we introduce the almost linear spaces, a generalization of linear spaces. We prove that if the almost linear space X has a finite basis then, as in the case of a linear space, the cardinality of bases for the almost linear space X is unique. In the case X = Wx + Vx, we prove that B'= {$\chi$'$_1,...,x'_n} is a basis for the algebraic dual X$^#$ of X if B = {$\chi$'$_1,...,x'_n} is a basis for the almost linear space X. And we have an example X($\neq$Wx + Vx) which has no such a basis.

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Testing for Lack of Fit via the Generalized Neyman Smooth Test

  • Lee, Geung-Hee
    • Journal of the Korean Statistical Society
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    • v.27 no.3
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    • pp.305-318
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    • 1998
  • Smoothing tests based on an L$_2$ error between a truncated courier series estimator and a true function have shown good powers for a wide class of alternatives, These tests have the same form of the Neyman smooth test whose performance depends on the selected order, a basis, the farm of estimators. We construct flexible data driven Neyman smooth tests by changing a basis, combining model selection criteria and different series estimators. A simulation study shows that the generalized Neyman smooth test with the best basis provides good power for a wider class of alternatives compared with other data driven Neyman smooth tests based on a fixed form of estimator, a fixed basis and a fixed criterion.

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Determining the Optimal Basis in Karmarkar's Algorithm (Karmarkar 기법의 최적기저 결정에 관한 연구)

  • Kim, Byeong-Jae;Park, Soon-Dal
    • Journal of the Korean Operations Research and Management Science Society
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    • v.16 no.1
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    • pp.89-96
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    • 1991
  • When a feasible solution approaches to the optimal extreme point in Karmakar's algorithm, components of the search direction vector for a solution converge at a certain value according to the corresponding columns of the optimal basis and the optimal nonbasis. By using this convergence properties of Karmarkar's algorithm, we can identify columns of the optimal basis before the final stage of the algorithm. The complexity of Karmarker's algorithm with newly proposed termination criterion does not increase. A numerical experiments for the problems which were generated by random numbers are also illustrated. Experimental results show that the number of iterations required for determining columns of the optimal basis depends on problems. For all cases, however, columns of the optimal basis are exactly verified when this termination criterion is used.

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Generation of Fixed Spectral Basis for Three-Dimensional Mesh Coding Using Dual Graph

  • Kim Sung-Yeol;Yoon Seung-Uk;Ho Yo-Sung
    • Proceedings of the IEEK Conference
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    • summer
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    • pp.137-142
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    • 2004
  • In this paper, we propose a new scheme for geometry coding of three-dimensional (3-D) mesh models using a fixed spectral basis. In order to code the mesh geometry information, we generate a fixed spectral basis using the dual graph derived from the 3-D mesh topology. After we partition a 3-D mesh model into several independent sub-meshes to reduce coding complexity, the mesh geometry information is projected onto the generated orthonormal bases which are the eigenvectors of the Laplacian matrix of the 3-D mesh. Finally, spectral coefficients are coded by a quantizer and a variable length coder. The proposed scheme can not only overcome difficulty of generating a fixed spectral basis, but also reduce coding complexity. Moreover, we can provide an efficient multi-resolution representation of 3-D meshes.

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A comparative study in Bayesian semiparametric approach to small area estimation

  • Heo, Simyoung;Kim, Dal Ho
    • Journal of the Korean Data and Information Science Society
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    • v.27 no.5
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    • pp.1433-1441
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    • 2016
  • Small area model provides reliable and accurate estimations when the sample size is not sufficient. Our dataset has an inherent nonlinear pattern which signicantly affects our inference. In this case, we could consider semiparametric models such as truncated polynomial basis function and radial basis function. In this paper, we study four Bayesian semiparametric models for small areas to handle this point. Four small area models are based on two kinds of basis function and different knots positions. To evaluate the different estimates, four comparison measurements have been employed as criteria. In these comparison measurements, the truncated polynomial basis function with equal quantile knots has shown the best result. In Bayesian calculation, we use Gibbs sampler to solve the numerical problems.

SOME PROPERTIES OF THE BASIS FINITE AUTOMATON

  • Melnikov, B.F.;Melnikova, A.A.
    • Journal of applied mathematics & informatics
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    • v.9 no.1
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    • pp.135-150
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    • 2002
  • The present paper discusses non-deterministic finite Rabin-scott's automate. The majority of works recently dealing with this subject were, in fact, concerned only with properties of a canonical term automata or of some objects equivalent to it. This article continues the series of works in which the authors state a different point of view, describing the finite automata as just another invariant of the given regular language called basis finite automaton. In this article the authors argue on some new properties for the basis finite automaton. One of them is included into basis automaton's table of binary relations. It is stated that this table can not contain either identical strings or identical columns. Another property depicts a possibility to obtain any finite automaton for a given regular language by the process of duplicating or combining some of its states.