• Title, Summary, Keyword: variational method

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PCA-based Variational Model Composition Method for Roust Speech Recognition with Time-Varying Background Noise (시변 잡음에 강인한 음성 인식을 위한 PCA 기반의 Variational 모델 생성 기법)

  • Kim, Wooil
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.12
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    • pp.2793-2799
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    • 2013
  • This paper proposes an effective feature compensation method to improve speech recognition performance in time-varying background noise condition. The proposed method employs principal component analysis to improve the variational model composition method. The proposed method is employed to generate multiple environmental models for the PCGMM-based feature compensation scheme. Experimental results prove that the proposed scheme is more effective at improving speech recognition accuracy in various SNR conditions of background music, compared to the conventional front-end methods. It shows 12.14% of average relative improvement in WER compared to the previous variational model composition method.

PERIODIC SOLUTIONS FOR THE NONLINEAR HAMILTONIAN SYSTEMS

  • Jung, Tacksun;Choi, Q-Heung
    • Korean Journal of Mathematics
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    • v.17 no.3
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    • pp.331-340
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    • 2009
  • We show the existence of nonconstant periodic solution for the nonlinear Hamiltonian systems with some nonlinearity. We approach the variational method. We use the critical point theory and the variational linking theory for strongly indefinite functional.

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GENERAL NONCONVEX SPLIT VARIATIONAL INEQUALITY PROBLEMS

  • Kim, Jong Kyu;Salahuddin, Salahuddin;Lim, Won Hee
    • Korean Journal of Mathematics
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    • v.25 no.4
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    • pp.469-481
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    • 2017
  • In this paper, we established a general nonconvex split variational inequality problem, this is, an extension of general convex split variational inequality problems in two different Hilbert spaces. By using the concepts of prox-regularity, we proved the convergence of the iterative schemes for the general nonconvex split variational inequality problems. Further, we also discussed the iterative method for the general convex split variational inequality problems.

A PARALLEL HYBRID METHOD FOR EQUILIBRIUM PROBLEMS, VARIATIONAL INEQUALITIES AND NONEXPANSIVE MAPPINGS IN HILBERT SPACE

  • Hieu, Dang Van
    • Journal of the Korean Mathematical Society
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    • v.52 no.2
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    • pp.373-388
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    • 2015
  • In this paper, a novel parallel hybrid iterative method is proposed for finding a common element of the set of solutions of a system of equilibrium problems, the set of solutions of variational inequalities for inverse strongly monotone mappings and the set of fixed points of a finite family of nonexpansive mappings in Hilbert space. Strong convergence theorem is proved for the sequence generated by the scheme. Finally, a parallel iterative algorithm for two finite families of variational inequalities and nonexpansive mappings is established.

AN ITERATIVE METHOD FOR NONLINEAR MIXED IMPLICIT VARIATIONAL INEQUALITIES

  • JEONG, JAE UG
    • Honam Mathematical Journal
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    • v.26 no.4
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    • pp.391-399
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    • 2004
  • In this paper, we develop an iterative algorithm for solving a class of nonlinear mixed implicit variational inequalities in Hilbert spaces. The resolvent operator technique is used to establish the equivalence between variational inequalities and fixed point problems. This equivalence is used to study the existence of a solution of nonlinear mixed implicit variational inequalities and to suggest an iterative algorithm for solving variational inequalities. In our results, we do not assume that the mapping is strongly monotone.

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THE USE OF ITERATIVE METHODS FOR SOLVING NAVEIR-STOKES EQUATION

  • Behzadi, Shadan Sadigh;Fariborzi Araghi, Mohammad Ali
    • Journal of applied mathematics & informatics
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    • v.29 no.1_2
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    • pp.381-394
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    • 2011
  • In this paper, a Naveir-Stokes equation is solved by using the Adomian's decomposition method (ADM), modified Adomian's decomposition method (MADM), variational iteration method (VIM), modified variational iteration method (MVIM), modified homotopy perturbation method (MHPM) and homotopy analysis method (HAM). The approximate solution of this equation is calculated in the form of series which its components are computed by applying a recursive relation. The existence and uniqueness of the solution and the convergence of the proposed methods are proved. A numerical example is studied to demonstrate the accuracy of the presented methods.

Facet Reflectivities as a Function of Waveguide width of Buried Channel Waveguides using the Field Profiles Obtained by the Variational Method (Variational 방법으로 구한 필드 분포를 이용한 도파로 폭에 따른 Buried Channel Waveguides의 단면 반사율)

  • Kim, Sang-Taek;Kim, Dong-Hoo;Kim, Boo-Gyoun
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.37 no.11
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    • pp.36-42
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    • 2000
  • We calculate the facet reflectivity as a function of the waveguide width of buried channel waveguides using the angular spectrum method and the field profiles obtained by the effective index method, the variational method and the modified variational method, respectively and discuss the results. As the waveguide width increases, the facet reflectivity of buried channel waveguides approaches to that of slab waveguides. As the waveguide width decreases, the facet reflectivity of quasi-TE mode decreases from that of slab waveguides, while that of quasi-TE mode increases from that of slab waveguides. The variation of the facet reflectivity of quasi-TE mode as a function of waveguide width is much larger than that of quasi-TM mode. When the aspect ratio is one, the difference between the facet reflectivity of quasi-TE mode and that of quasi-TM mode using the variational method and the modified variational method is negligible, while the difference between the facet reflectivity of quasi-TE mode and that of quasi-TM mode using the effective index method is large. In the case of quasi-TE mode, the facet reflectivity using the angular spectrum method and the field profiles obtained by the modified variational method could be more accurate than that obtained by the effective method. In the case of quasi-TM mode, the facet reflectivities obtained by the various methods are almost the same.

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A GENERAL ITERATIVE METHOD BASED ON THE HYBRID STEEPEST DESCENT SCHEME FOR VARIATIONAL INCLUSIONS, EQUILIBRIUM PROBLEMS

  • Tian, Ming;Lan, Yun Di
    • Journal of applied mathematics & informatics
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    • v.29 no.3_4
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    • pp.603-619
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    • 2011
  • To the best of our knowledge, it would probably be the first time in the literature that we clarify the relationship between Yamada's method and viscosity iteration correctly. We design iterative methods based on the hybrid steepest descent algorithms for solving variational inclusions, equilibrium problems. Our results unify, extend and improve the corresponding results given by many others.

APPROXIMATION OF SOLUTIONS OF A GENERALIZED VARIATIONAL INEQUALITY PROBLEM BASED ON ITERATIVE METHODS

  • Cho, Sun-Young
    • Communications of the Korean Mathematical Society
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    • v.25 no.2
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    • pp.207-214
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    • 2010
  • In this paper, a generalized variational inequality problem is considered. An iterative method is studied for approximating a solution of the generalized variational inequality problem. Strong convergence theorem are established in a real Hilbert space.

Computation of Wave Propagation by Scatter Method Associated with Variational Approximation (변분근사식과 연계된 산란체법에 의한 파랑변형 계산)

  • Seo, Seung-Nam
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.20 no.6
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    • pp.553-563
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    • 2008
  • If an arbitrary topography is approximated to a number of vertical steps, both variational approximation and eigenfunction expansion method can be used to compute linear wave transformation over the bottom. In this study a scatterer method associated with variational approximation is proposed to calculate reflection and transmission coefficients. Present method may be shown to be more simple and direct than the successive-application-matrix method by O'Hare and Davies. And Several numerical examples are given which are in good agreement with existing results.