• 제목/요약/키워드: 3-Point Approximation

검색결과 124건 처리시간 0.023초

A VISCOSITY APPROXIMATIVE METHOD TO CES$\`{A}$RO MEANS FOR SOLVING A COMMON ELEMENT OF MIXED EQUILIBRIUM, VARIATIONAL INEQUALITIES AND FIXED POINT PROBLEMS

  • Jitpeera, Thanyarat;Katchang, Phayap;Kumam, Poom
    • Journal of applied mathematics & informatics
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    • 제29권1_2호
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    • pp.227-245
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    • 2011
  • In this paper, we introduce a new iterative method for finding a common element of the set of solutions for mixed equilibrium problem, the set of solutions of the variational inequality for a ${\beta}$inverse-strongly monotone mapping and the set of fixed points of a family of finitely nonexpansive mappings in a real Hilbert space by using the viscosity and Ces$\`{a}$ro mean approximation method. We prove that the sequence converges strongly to a common element of the above three sets under some mind conditions. Our results improve and extend the corresponding results of Kumam and Katchang [A viscosity of extragradient approximation method for finding equilibrium problems, variational inequalities and fixed point problems for nonexpansive mapping, Nonlinear Analysis: Hybrid Systems, 3(2009), 475-86], Peng and Yao [Strong convergence theorems of iterative scheme based on the extragradient method for mixed equilibrium problems and fixed point problems, Mathematical and Computer Modelling, 49(2009), 1816-828], Shimizu and Takahashi [Strong convergence to common fixed points of families of nonexpansive mappings, Journal of Mathematical Analysis and Applications, 211(1) (1997), 71-83] and some authors.

점 데이타의 Rational B-spline 근사를 통한 역공학 (Rational B-spline Approximation of Point Data For Reverse Engineering)

  • 이현직;고태조;김희술
    • 한국정밀공학회지
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    • 제16권5호통권98호
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    • pp.160-168
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    • 1999
  • This paper describes one method of reverse engineering that machines a free form shape without descriptive model. A portable five-axes 3D CMM was used to digitize point data from physical model. After approximation by rational B-spline curve from digitized point data of a geometric shape, a surface was constructed by the skinning method of the cross-sectional design technique. Since a surface patch was segmented by fifteen part, surface merging was also implemented to assure the surface boundary continuity. Finally, composite surface was transferred to commercial CAD/CAM system through IFES translation in order to machine the modeled geometric shape.

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Fast Algorithms for Computing Floating-Point Reciprocal Cube Root Functions

  • Leonid Moroz;Volodymyr Samotyy;Cezary Walczyk
    • International Journal of Computer Science & Network Security
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    • 제23권6호
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    • pp.84-90
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    • 2023
  • In this article the problem of computing floating-point reciprocal cube root functions is considered. Our new algorithms for this task decrease the number of arithmetic operations used for computing $1/{\sqrt[3]{x}}$. A new approach for selection of magic constants is presented in order to minimize the computation time for reciprocal cube roots of arguments with movable decimal point. The underlying theory enables partitioning of the base argument range x∈[1,8) into 3 segments, what in turn increases accuracy of initial function approximation and decreases the number of iterations to one. Three best algorithms were implemented and carefully tested on 32-bit microcontroller with ARM core. Their custom C implementations were favourable compared with the algorithm based on cbrtf(x) function taken from C <math.h> library on three different hardware platforms. As a result, the new fast approximation algorithm for the function $1/{\sqrt[3]{x}}$ was determined that outperforms all other algorithms in terms of computation time and cycle count.

이진 가중치 신경망의 하드웨어 구현을 위한 고정소수점 연산 정확도 분석 (Accuracy Analysis of Fixed Point Arithmetic for Hardware Implementation of Binary Weight Network)

  • 김종현;윤상균
    • 전기전자학회논문지
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    • 제22권3호
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    • pp.805-809
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    • 2018
  • 본 연구에서는 이진 가중치 신경망(BWN)을 부동소수점 데이터를 사용하여 학습시킨 후에, 학습된 파라미터와 주요연산을 고정소수점으로 근사화시키는 과정에서 정확도의 변화를 분석하였다. 신경망을 이루고 있는 각 계층의 입력 데이터와 컨볼루션 연산의 계산에 고정소수점 수를 사용했으며, 이때 고정소수점 수의 전체 bit 수와 소수점 이하 bit 수에 변화를 주면서 정확도 변화를 관찰하였다. 각 계층의 입력 값과 중간 계산값의 정수 부분의 손실이 발생하지 않으면 고정소수점 연산을 사용해도 부동소수점 연산에 비해 큰 정확도 감소가 없었다. 그리고 오버플로가 발생하는 경우에 고정소수점 수의 최대 또는 최소값으로 근사시켜서 정확도 감소를 줄일 수 있었다. 이 연구결과는 FPGA 기반의 BWN 가속기를 구현할 때에 필요한 메모리와 하드웨어 요구량을 줄이는 데 사용될 수 있다.

APPROXIMATION OF NEAREST COMMON FIXED POINTS OF ASYMPTOTICALLY I-NONEXPANSIVE MAPPINGS IN BANACH SPACES

  • Cho, Yeol-Je;Hussain, Nawab;Pathak, Hemant Kumar
    • 대한수학회논문집
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    • 제26권3호
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    • pp.483-498
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    • 2011
  • In this paper, we introduce a new class of uniformly point-wise R-subweakly commuting self-mappings and prove several common fixed point theorems and best approximation results for uniformly point-wise R-subweakly commuting asymptotically I-nonexpansive mappings in normed linear spaces. We also establish some results concerning strong convergence of nearest common fixed points of asymptotically I-non-expansive mappings in reflexive Banach spaces with a uniformly G$\^{a}$teaux differentiable norm. Our results unify and generalize various known results given by some authors to a more general class of noncommuting mappings.

GENERALIZED SYMMETRICAL SIGMOID FUNCTION ACTIVATED NEURAL NETWORK MULTIVARIATE APPROXIMATION

  • ANASTASSIOU, GEORGE A.
    • Journal of Applied and Pure Mathematics
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    • 제4권3_4호
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    • pp.185-209
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    • 2022
  • Here we exhibit multivariate quantitative approximations of Banach space valued continuous multivariate functions on a box or ℝN, N ∈ ℕ, by the multivariate normalized, quasi-interpolation, Kantorovich type and quadrature type neural network operators. We treat also the case of approximation by iterated operators of the last four types. These approximations are achieved by establishing multidimensional Jackson type inequalities involving the multivariate modulus of continuity of the engaged function or its high order Fréchet derivatives. Our multivariate operators are defined by using a multidimensional density function induced by the generalized symmetrical sigmoid function. The approximations are point-wise and uniform. The related feed-forward neural network is with one hidden layer.

Newton-Raphson 방식의 제곱근 근사를 위한 초기값의 최적화 (Initial Point Optimization for Square Root Approximation based on Newton-Raphson Method)

  • 최창순;이진용;김영록
    • 대한전자공학회논문지SD
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    • 제43권3호
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    • pp.15-20
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    • 2006
  • 본 논문은 Newton-Raphson 방법을 기반으로 하는 table-driven 알고리듬에 대해 연구되었다. 특히 본 논문에서는 Newton-Raphson 방법을 이용한 제곱근 근사에 중점을 두었다. Newton-Raphson방법에서 최적화된 초기근사해를 구하게 되면 제곱근 근사의 정확성을 높일 수 있으며, 연산 속도 또한 빨라지게 된다. 그러므로 Newton-Raphson 알고리듬에서 초기근사해를 어떻게 결정하느냐하는 것이 전체적인 알고리듬의 성능을 평가하게 되는 중요한 이슈이다. 본 논문에서는 Newton-Raphson 알고리듬의 초기 근사해를 기하평균을 기준으로 테이블에 저장, 연산의 속도와 최대 오차율을 줄일 수 있음을 확인하였다.

On A Symbolic Method for Error Estimation of a Mixed Interpolation

  • Thota, Srinivasarao
    • Kyungpook Mathematical Journal
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    • 제58권3호
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    • pp.453-462
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    • 2018
  • In this paper, we present a symbolic formulation of the error obtained due to an approximation of a given function by the mixed-interpolating function. Using the proposed symbolic method, we compute the error evaluation operator as well as the error estimation at any arbitrary point. We also present an algorithm to compute an approximation of a function by the mixed interpolation technique in terms of projector operator. Certain examples are presented to illustrate the proposed algorithm. Maple implementation of the proposed algorithm is discussed with sample computations.

생체모방 로봇을 위한 비선형 항법 필터 (A Nonlinear Navigation Filter for Biomimetic Robot)

  • 성상만
    • 제어로봇시스템학회논문지
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    • 제18권3호
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    • pp.175-180
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    • 2012
  • A nonlinear navigation filter for biomimetic robot using analytic approximation of mean and covariance of state variable is proposed. The approximations are performed at the time update step in the filter structure. The mean is approximated to the 3rd order of Taylor's series expansion of true mean and the covariance is approximated to the 3rd order either. The famous EKF is a nonlinear filtering method approximating the mean to 1st order and the covariance to the 3rd order. The UKF approximate them to the higher orders by numerical method. The proposed method derived a analytical approximation of them for navigation system and therefore don't need so called sigma point transformation in UKF. The simulation results show that the proposed method can be a good alternative of UKF in the systems which require less computational burden.