• Title, Summary, Keyword: operator approximation

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ON RELATIONSHIPS AMONG INTUITIONISTIC FUZZY APPROXIMATION OPERATORS, INTUITIONISTIC FUZZY TOPOLOGY AND INTUITIONISTIC FUZZY AUTOMATA

  • Tiwari, S.P.
    • Journal of applied mathematics & informatics
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    • v.28 no.1_2
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    • pp.99-107
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    • 2010
  • This paper is a study about the relationships among topologies and intuitionistic fuzzy topology induced, respectively, by approximation operators and an intuitionistic fuzzy approximation operator associated with an approximation space (X, R), when the relation R on X is precisely reflexive and transitive. In particular, we consider an intuitionistic fuzzy approximation operator on an approximation space X (i.e., a set X with a reflexive and transitive relation on it), which turns out to be an intuitionistic fuzzy closure operator. This intuitionistic fuzzy closure operator gives rise to two saturated fuzzy topologies on X and it turns out that all the level topologies of one of the fuzzy topology coincide and equal to the topology analogously induced on X by a crisp approximation operator. These observations are then applied to intuitionistic fuzzy automata.

On Approximation by Post-Widder and Stancu Operators Preserving x2

  • Rempulska, Lucyna;Skorupka, Mariola
    • Kyungpook Mathematical Journal
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    • v.49 no.1
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    • pp.57-65
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    • 2009
  • In the papers [5]-[7] was examined approximation of functions by the modified Sz$\'{a}$sz-Mrakyan operators and other positive linear operators preserving $e_2(x)=x^2$. In this paper we introduce the Post-Widder and Stancu operators preserving $x^2$ in polynomial weighted spaces. We show that these operators have better approximation properties than classical Post-Widder and Stancu operators.

Stability Improved Split-step Parabolic Equation Model

  • Kim, Tae-Hyun;Seong, Woojae
    • The Journal of the Acoustical Society of Korea
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    • v.21 no.3E
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    • pp.105-111
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    • 2002
  • The parabolic equation technique provides an excellent model to describe the wave phenomena when there exists a predominant direction of propagation. The model handles the square root wave number operator in paraxial direction. Realization of the pseudo-differential square root operator is the essential part of the parabolic equation method for its numerical accuracy. The wide-angled approximation of the operator is made based on the Pade series expansion, where the branch line rotation scheme can be combined with the original Pade approximation to stabilize its computational performance for complex modes. The Galerkin integration has been employed to discretize the depth-dependent operator. The benchmark tests involving the half-infinite space, the range independent and dependent environment will validate the implemented numerical model.

ON A LIMIT CLASS OF LORENTZ OPERATOR IDEALS

  • Song, Hi Ja
    • Korean Journal of Mathematics
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    • v.11 no.2
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    • pp.93-109
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    • 2003
  • We give an extensive presentation of results about the behaviour of the approximation operator ideals $\mathcal{L}_{{\infty},q}$ in connection with the Lorentz operator ideals $\mathcal{L}_{p,q}$.

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A NOTE ON APPROXIMATION OF SOLUTIONS OF A K-POSITIVE DEFINITE OPERATOR EQUATIONS

  • Osilike, M.O.;Udomene, A.
    • Bulletin of the Korean Mathematical Society
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    • v.38 no.2
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    • pp.231-236
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    • 2001
  • In this note we construct a sequence of Picard iterates suitable for the approximation of solutions of K-positive definite operator equations in arbitrary real Banach spaces. Explicit error estimate is obtained and convergence is shown to be as fast as a geometric progression.

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VISCOSITY METHODS OF APPROXIMATION FOR A COMMON SOLUTION OF A FINITE FAMILY OF ACCRETIVE OPERATORS

  • Chen, Jun-Min;Zhang, Li-Juan;Fan, Tie-Gang
    • East Asian mathematical journal
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    • v.27 no.1
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    • pp.11-21
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    • 2011
  • In this paper, we try to extend the viscosity approximation technique to find a particular common zero of a finite family of accretive mappings in a Banach space which is strictly convex reflexive and has a weakly sequentially continuous duality mapping. The explicit viscosity approximation scheme is proposed and its strong convergence to a solution of a variational inequality is proved.

A LOCAL APPROXIMATION METHOD FOR THE SOLUTION OF K-POSITIVE DEFINITE OPERATOR EQUATIONS

  • Chidume, C.E.;Aneke, S.J.
    • Bulletin of the Korean Mathematical Society
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    • v.40 no.4
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    • pp.603-611
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    • 2003
  • In this paper we extend the definition of K-positive definite operators from linear to Frechet differentiable operators. Under this setting, we derive from the inverse function theorem a local existence and approximation results corresponding to those of Theorems land 2 of the authors [8], in an arbitrary real Banach space. Furthermore, an asymptotically K-positive definite operator is introduced and a simplified iteration sequence which converges to the unique solution of an asymptotically K-positive definite operator equation is constructed.

A unified solution to optimal Hankel-Norm approximation problem (최적 한켈 놈 근사화 문제의 통합형 해)

  • Youn, Sang-Soon;Kwon, Oh-Kyu
    • Journal of Institute of Control, Robotics and Systems
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    • v.4 no.2
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    • pp.170-177
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    • 1998
  • In this paper, a unified solution of Hankel norm approximation problem is proposed by $\delta$-operator. To derive the main result, all-pass property is derived from the inner and co-inner property in the $\delta$-domain. The solution of all-pass becomes an optimal Hankel norm approximation problem in .delta.-domain through LLFT(Low Linear Fractional Transformation) inserting feedback term $\phi(\gamma)$, which is a free design parameter, to hold the error bound desired against the variance between the original model and the solution of Hankel norm approximation problem. The proposed solution does not only cover continuous and discrete ones depending on sampling interval but also plays a key role in robust control and model reduction problem. The verification of the proposed solution is exemplified via simulation for the zero-order Hankel norm approximation problem and the model reduction problem applied to a 16th order MIMO system.

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A KOROVKIN TYPE APPROXIMATION THEOREM FOR DOUBLE SEQUENCES OF POSITIVE LINEAR OPERATORS OF TWO VARIABLES IN A-STATISTICAL SENSE

  • Demirci, Kamil;Dirik, Fadime
    • Bulletin of the Korean Mathematical Society
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    • v.47 no.4
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    • pp.825-837
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    • 2010
  • In this paper, we obtain a Korovkin type approximation theorem for double sequences of positive linear operators of two variables from $H_w$ (K) to C (K) via A-statistical convergence. Also, we construct an example such that our new approximation result works but its classical case does not work. Furthermore, we study the rates of A-statistical convergence by means of the modulus of continuity.

APPROXIMATION-SOLVABILITY OF A CLASS OF A-MONOTONE VARIATIONAL INCLUSION PROBLEMS

  • Verma, Ram U.
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.8 no.1
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    • pp.55-66
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    • 2004
  • First the notion of the A-monotonicity is applied to the approximation - solvability of a class of nonlinear variational inclusion problems, and then the convergence analysis is given based on a projection-like method. Results generalize nonlinear variational inclusions involving H-monotone mappings in the Hilbert space setting.

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