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Fully implicational methods for approximate reasoning based on interval-valued fuzzy sets 被引量:4
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作者 Huawen Liu 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2010年第2期224-232,共9页
The aim of this paper is to discuss the approximate rea- soning problems with interval-valued fuzzy environments based on the fully implicational idea. First, this paper constructs a class of interval-valued fuzzy imp... The aim of this paper is to discuss the approximate rea- soning problems with interval-valued fuzzy environments based on the fully implicational idea. First, this paper constructs a class of interval-valued fuzzy implications by means of a type of impli- cations and a parameter on the unit interval, then uses them to establish fully implicational reasoning methods for interval-valued fuzzy modus ponens (IFMP) and interval-valued fuzzy modus tel- lens (IFMT) problems. At the same time the reversibility properties of these methods are analyzed and the reversible conditions are given. It is shown that the existing unified forms of α-triple I (the abbreviation of triple implications) methods for FMP and FMT can be seen as the particular cases of our methods for IFMP and IFMT. 展开更多
关键词 approximate reasoning interval-valued fuzzy set interval-valued fuzzy implication fully implicational method re- versibility.
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The Exact and Approximate Solutions of Some Boundary Value Problems in Domains with Angular Points of the Boundary
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作者 Irina Menshova Mikhail Kovalenko 《Journal of Applied Mathematics and Physics》 2017年第1期39-44,共6页
On the basis of the exact solution of biharmonic problems of elasticity theory in a half-strip one possible reason is shown of those problems that arise when an approximate or numerical approaches leading the solution... On the basis of the exact solution of biharmonic problems of elasticity theory in a half-strip one possible reason is shown of those problems that arise when an approximate or numerical approaches leading the solution of boundary value problems to infinite systems of linear algebraic equations. Construction of exact solutions of some boundary value problems for differential equations in partial derivatives is not possible without their extensions to Riemann surfaces. Moreover, each of the boundary value problem corresponds to its Riemann surface. This fact is important to consider when developing an effective approximate and numerical methods of solving boundary value problems. 展开更多
关键词 BOUNDARY value Problems EXACT and approximate Solutions
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APPROXIMATION ANALYSES FOR FUZZY VALUED FUNCTIONS IN L_1(μ)-NORM BY REGULAR FUZZY NEURAL NETWORKS 被引量:4
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作者 Liu Puyin (Dept. of System Eng. and Math., National Univ. of Defence Tech., Changsha 410073) 《Journal of Electronics(China)》 2000年第2期132-138,共7页
By defining fuzzy valued simple functions and giving L1(μ) approximations of fuzzy valued integrably bounded functions by such simple functions, the paper analyses by L1(μ)-norm the approximation capability of four-... By defining fuzzy valued simple functions and giving L1(μ) approximations of fuzzy valued integrably bounded functions by such simple functions, the paper analyses by L1(μ)-norm the approximation capability of four-layer feedforward regular fuzzy neural networks to the fuzzy valued integrably bounded function F : Rn → FcO(R). That is, if the transfer functionσ: R→R is non-polynomial and integrable function on each finite interval, F may be innorm approximated by fuzzy valued functions defined as to anydegree of accuracy. Finally some real examples demonstrate the conclusions. 展开更多
关键词 FUZZY valueD simple function REGULAR FUZZY neural network L1(μ) approximATION Universal approximator
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Development of the Decoupled Discreet-Time Jacobian Eigenvalue Approximation for Situational Awareness Utilizing Open PDC 被引量:1
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作者 Sean D. Kantra Elham B. Makram 《Journal of Power and Energy Engineering》 2016年第9期21-35,共15页
With the increased number of PMUs in the power grid, effective high speed, realtime methods to ascertain relevant data for situational awareness are needed. Several techniques have used data from PMUs in conjunction w... With the increased number of PMUs in the power grid, effective high speed, realtime methods to ascertain relevant data for situational awareness are needed. Several techniques have used data from PMUs in conjunction with state estimation to assess system stability and event detection. However, these techniques require system topology and a large computational time. This paper presents a novel approach that uses real-time PMU data streams without the need of system connectivity or additional state estimation. The new development is based on the approximation of the eigenvalues related to the decoupled discreet-time power flow Jacobian matrix using direct openPDC data in real-time. Results are compared with other methods, such as Prony’s method, which can be too slow to handle big data. The newly developed Discreet-Time Jacobian Eigenvalue Approximation (DDJEA) method not only proves its accuracy, but also shows its effectiveness with minimal computational time: an essential element when considering situational awareness. 展开更多
关键词 SYNCHROPHASOR PMU Open PDC Power Flow Jacobian Decoupled Discreet-Time Jacobian approximation Singular value Decomposition (SVD) Prony Analysis
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ORTHOGONAL POLYNOMIALS AND DETERMINANT FORMULAS OF FUNCTION-VALUED PADE-TYPE APPROXIMATION USING FOR SOLUTION OF INTEGRAL EQUATIONS 被引量:2
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作者 顾传青 潘宝珍 吴蓓蓓 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2006年第6期853-860,共8页
To solve Fredholm integral equations of the second kind, a generalized linear functional is introduced and a new function-valued Padé-type approximation is defined. By means of the power series expansion of the s... To solve Fredholm integral equations of the second kind, a generalized linear functional is introduced and a new function-valued Padé-type approximation is defined. By means of the power series expansion of the solution, this method can construct an approximate solution to solve the given integral equation. On the basis of the orthogonal polynomials, two useful determinant expressions of the numerator polynomial and the denominator polynomial for Padé-type approximation are explicitly given. 展开更多
关键词 generalized linear functional function-valued Padé-type approximation Fredholm integral equation orthogonal polynomial determinant formula
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Stochastic level-value approximation for quadratic integer convex programming
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作者 彭拯 邬冬华 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2008年第6期801-809,共9页
We propose a stochastic level value approximation method for a quadratic integer convex minimizing problem in this paper. This method applies an importance sampling technique, and make use of the cross-entropy method ... We propose a stochastic level value approximation method for a quadratic integer convex minimizing problem in this paper. This method applies an importance sampling technique, and make use of the cross-entropy method to update the sample density functions. We also prove the asymptotic convergence of this algorithm, and report some numerical results to illuminate its effectiveness. 展开更多
关键词 quadratic integer convex programming stochastic level value approximation cross-entropy method asymptotic convergence
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Exponential Convergence of Finite-dimensional Approximations to Linear Bond-based Peridynamic Boundary Value Problems
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作者 WU HAO 《Communications in Mathematical Research》 CSCD 2018年第3期278-288,共11页
In this paper, we demonstrate that the finite-dimensional approximations to the solutions of a linear bond-based peridynamic boundary value problem converge to the exact solution exponentially with the analyticity ass... In this paper, we demonstrate that the finite-dimensional approximations to the solutions of a linear bond-based peridynamic boundary value problem converge to the exact solution exponentially with the analyticity assumption of the forcing term, therefore greatly improve the convergence rate derived in literature. 展开更多
关键词 PERIDYNAMICS exponential convergence nonlocal boundary value problem analytic function finite-dimensional approximation
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Degeneracy Cases of Generalized Inverse Function-Valued Padé Approximation 被引量:1
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作者 潘宝珍 顾传青 《Journal of Shanghai University(English Edition)》 CAS 2004年第3期258-263,共6页
A new generalized inverse function-valued Padé approximation (GIFPA) was defined. Existence condition of GIFPA was given and its uniqueness theorem was proved. All possible degeneracy cases of GIFPA were discusse... A new generalized inverse function-valued Padé approximation (GIFPA) was defined. Existence condition of GIFPA was given and its uniqueness theorem was proved. All possible degeneracy cases of GIFPA were discussed and constructed. An example was given to illustrate its application. 展开更多
关键词 Generalized inverse function-valued Padé approximation (GIFPA) degeneracy cases existence and uniqueness.
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Least-squares function-valued Padé-type approximation and its application in solving integral equations 被引量:1
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作者 潘宝珍 刘利九 《Journal of Shanghai University(English Edition)》 CAS 2010年第1期66-70,共5页
To solve the Fredholm integral equations of the second kind, a new notion of the least-squares orthogonal polyno- mials of function-valued Pade-type approximation is introduced. On the basis of the error formula, the ... To solve the Fredholm integral equations of the second kind, a new notion of the least-squares orthogonal polyno- mials of function-valued Pade-type approximation is introduced. On the basis of the error formula, the least-squares function: valued Pad&type approximation is constructed. Their existence and uniqueness are studied. A recursive computation formula of the least-squares function-valued Padetype approximation is given. In the end, an example is given to show that the method is effective and stable. 展开更多
关键词 least-squaxes orthogonal polynomial function-valued Pade-type approximation Fredholm integral equation
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VALUE DISTRIBUTION THEORY AND DIOPHANTINE APPROXIMATION
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作者 Peichu Hu Chungchun Yang 《Analysis in Theory and Applications》 2005年第2期101-117,共17页
In this paper, we will introduce some problems and results between Diophantine approximation and value distribution theory.
关键词 value distribution Diophantine approximation
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Expansion of the Decoupled Discreet-Time Jacobian Eigenvalue Approximation for Model-Free Analysis of PMU Data
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作者 Sean D. Kantra Elham B. Makram 《Journal of Power and Energy Engineering》 2017年第6期14-35,共22页
This paper proposes an extension of the algorithm in [1], as well as utilization of the wavelet transform in event detection, including High Impedance Fault (HIF). Techniques to analyze the abundant data of PMUs quick... This paper proposes an extension of the algorithm in [1], as well as utilization of the wavelet transform in event detection, including High Impedance Fault (HIF). Techniques to analyze the abundant data of PMUs quickly and effectively are paramount to increasing response time to events and unstable parameters. With the amount of data PMUs output, unstable parameters, tie line oscillations, and HIFs are often overlooked in the bulk of the data. This paper explores model-free techniques to attain stability information and determine events in real-time. When full system connectivity is unknown, many traditional methods requiring other bus measurements can be impossible or computationally extensive to apply. The traditional method of interest is analyzing the power flow Jacobian for singularities and system weak points, attained by applying singular value decomposition. This paper further develops upon the approach in [1] to expand the Discrete-Time Jacobian Eigenvalue Approximation (DDJEA), giving values to significant off-diagonal terms while establishing a generalized connectivity between correlated buses. Statistical linear models are applied over large data sets to prove significance to each term. Then the off diagonal terms are given time-varying weights to account for changes in topology or sensitivity to events using a reduced system model. The results of this novel method are compared to the present errors of the previous publication in order to quantify the degree of improvement that this novel method imposes. The effective bus eigenvalues are briefly compared to Prony analysis to check similarities. An additional application for biorthogonal wavelets is also introduced to detect event types, including the HIF, for PMU data. 展开更多
关键词 SYNCHROPHASOR PMU openPDC Power Flow JACOBIAN Decoupled Discrete-Time JACOBIAN approximation (DDJEA) SINGULAR value Decomposition (SVD) High Impedance Fault (HIF) Discrete Wavelet Transform (DWT)
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ON VECTOR VALUED FUNCTION APPROXIMATION USING A PEAK NORM
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作者 G.A.Watson 《Analysis in Theory and Applications》 1996年第2期1-12,共12页
A peak norm is defined for Lp spaces of E-valued Bochner integrable functions, where E is a Banach space, and best approximations from a sun to elements of the space are characterized. Applications are given to some f... A peak norm is defined for Lp spaces of E-valued Bochner integrable functions, where E is a Banach space, and best approximations from a sun to elements of the space are characterized. Applications are given to some families of simultaneous best approximation problems. 展开更多
关键词 ON VECTOR valueD FUNCTION approximATION USING A PEAK NORM 任气
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A New Vector-Valued Padé-Type Approximation in the Inner Space
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作者 Chunjing Li 《Numerical Mathematics A Journal of Chinese Universities(English Series)》 SCIE 2006年第2期127-136,共10页
A new vector-valued Pad′e-type approximation is defined by introducing a gener- alized vector-valued linear functional from a scalar polynomial space to a vector space. Some algebraic properties and error formulas ar... A new vector-valued Pad′e-type approximation is defined by introducing a gener- alized vector-valued linear functional from a scalar polynomial space to a vector space. Some algebraic properties and error formulas are presented. The expressions of this Pad′e-type ap- proximants are provided with the generating function form and the determinant form. 展开更多
关键词 逼近 内部空间 标量多项式空间 向量估计
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Function-valued partial Padé-type approximation method for estimating eigenvalues of Fredholm integral equation of the second kind
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作者 顾传青 沈进东 《Journal of Shanghai University(English Edition)》 CAS 2007年第6期531-535,共5页
Abstract A new function-valued partial Padé-type approximation was introduced in the polynomial space, and an explicit determinant formula was derived by means of some orthogonal polynomials. This method can be a... Abstract A new function-valued partial Padé-type approximation was introduced in the polynomial space, and an explicit determinant formula was derived by means of some orthogonal polynomials. This method can be applied to estimating surplus eigenvalues of the Fredholm integral equation of the second kind when its partial eigenvalues have been known, and at the same time, it can be applied to solving the approximating solution of the given equation. 展开更多
关键词 linear functional function-valued partial Padé approximation DETERMINANT Fredholm integral equation of thesecond kind eigenvalue.
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Computational Aspect For Function-Valued Padé-Type Approximation
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作者 Chuanqing Gu Jindong Shen 《Numerical Mathematics A Journal of Chinese Universities(English Series)》 SCIE 2007年第2期171-180,共10页
The computational problems of two special determinants are investigated. Those determinants appear in the construction of the function-valued Pade-type approximation for computing Fredholm integral equation of the sec... The computational problems of two special determinants are investigated. Those determinants appear in the construction of the function-valued Pade-type approximation for computing Fredholm integral equation of the second kind. The main tool to be used in this paper is the well-known Schur complement theorem. 展开更多
关键词 函数值Padé逼近 计算问题 行列式 Schur余角定理
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Light Propagation in the Second post-Newtonian Approximation of Scalar-Tensor Theory of Gravity 被引量:2
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作者 DONG Peng LI Lei 《Communications in Theoretical Physics》 SCIE CAS CSCD 2011年第3期457-461,共5页
In this paper, we use the metric coefficients and the equation of motion obtained in the second post- Newtonian approximation of scalar-tensor theory to derive the second-order light propagation equation and the light... In this paper, we use the metric coefficients and the equation of motion obtained in the second post- Newtonian approximation of scalar-tensor theory to derive the second-order light propagation equation and the light deflection angle and compare it with previous works. These results are useful for precision astrometry missions like ASTROD, GALA, Darwin and SIM which aim at astrometry with micro-arcsecond and nano-aresecond accuracies, and need for the second post-Newtonian framework and ephemeris for observations to determine the stellar and spacecraft positions. 展开更多
关键词 post-newtonian approximation scalar-tensor theory light propagation
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The Existence and Uniqueness of Solutions to Systems of Second-order Ordinary Differential Equations Boundary Value Problem in Absract Space 被引量:2
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作者 武力兵 孙涛 何希勤 《Chinese Quarterly Journal of Mathematics》 CSCD 2011年第4期573-577,共5页
In this paper, it is discussed by using cone and upper and lower solutions mono- tone iterative theory of mixed monotone operator that the bounary value problem is more generalized style to system of equations in the ... In this paper, it is discussed by using cone and upper and lower solutions mono- tone iterative theory of mixed monotone operator that the bounary value problem is more generalized style to system of equations in the form of -u = f(t, u, v) -v = g(t, u, v) u(0) = u(1) = 0 v(0) = v(1) = 0 in abstract space. Moreover, it is obtained unique solutions for system of equations and error estimations between approximation iteration sequence and exact solution under more simpler conditions. Therefore, some new results which extend and improve the related known works in the literatures are obtained. 展开更多
关键词 systems of equations bounary value problem CONE approximation solution
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Randomized Generalized Singular Value Decomposition 被引量:1
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作者 Wei Wei Hui Zhang +1 位作者 Xi Yang Xiaoping Chen 《Communications on Applied Mathematics and Computation》 2021年第1期137-156,共20页
The generalized singular value decomposition(GSVD)of two matrices with the same number of columns is a very useful tool in many practical applications.However,the GSVD may suffer from heavy computational time and memo... The generalized singular value decomposition(GSVD)of two matrices with the same number of columns is a very useful tool in many practical applications.However,the GSVD may suffer from heavy computational time and memory requirement when the scale of the matrices is quite large.In this paper,we use random projections to capture the most of the action of the matrices and propose randomized algorithms for computing a low-rank approximation of the GSVD.Serval error bounds of the approximation are also presented for the proposed randomized algorithms.Finally,some experimental results show that the proposed randomized algorithms can achieve a good accuracy with less computational cost and storage requirement. 展开更多
关键词 Generalized singular value decomposition Randomized algorithm Low-rank approximation Error analysis
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On the Monotone Iterative Method for Set Valued Equation 被引量:2
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作者 TIAN Yan LEI Jin-gan (College of Mathematics and Computer Science, Wuhan University, Wuhan 430072, China) 《Wuhan University Journal of Natural Sciences》 CAS 2000年第1期22-26,共5页
This paper deals with the monotone iterative method for set -- valued operator equation in ordered normed space. Some results for the case of single valued operator are generalized here, as an application, a discontin... This paper deals with the monotone iterative method for set -- valued operator equation in ordered normed space. Some results for the case of single valued operator are generalized here, as an application, a discontinuous nonlinear differential equation problem is discussed. 展开更多
关键词 ordered normed space set-valued operator approximate solution
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FAST APPROXIMATE INVERSION OF MAGNETOTELLURIC(FAIMT) DATA FOR A HORIZONTALLY LAYERED EARTH WITH NEAR-SURFACE INHOMOGENEITIES
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作者 孙传文 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 1997年第1期7-18,共12页
This paper discusses use of approximations and the Integral Mean Value Theorem to show that 6 coefficients approximately describe the distortions of near surface inhomogeneities on the MT field of a horizontally layer... This paper discusses use of approximations and the Integral Mean Value Theorem to show that 6 coefficients approximately describe the distortions of near surface inhomogeneities on the MT field of a horizontally layered earth model. When these 6 coefficients are considered together with those of the magnetic field of a horizontally layered earth model,the analytic and approximate wave impedance equations can be derived for the MT response of a horizontally layered earth model with near-surface 2-D and 3-D inhomogeneities. These approximate wave impedance equations are used with inverted MT data for 2-D and 3-D forward modelling. Although these 6 coefficients cannot be determined before inversion,initial estimates can be used. The 6 coefficients and the asistivity and thickness of each layer of a horizontally layered earth can be obtained by using published inversion methods. The 6 coefficients give important informaion (depths and resistivities) on the near-surface inhomogenelties.The authors inverted 2-D and 3-D theoretical models for Fast Approximate Inversion of Magnetotelluric (FAIMT) data for a horizontally layered earth with near-surface inhomogeneities compares favorably with traditional invrsion methods, especially for inverting regional or basin structures. This method simplifies computation and gives a reasonable 1 -D geological model with fewer nonuniquenas problems. 展开更多
关键词 MAGNETOTELLURIC 3-D INVERSIONS inhomogeneity integral mean value theorem LAYERED EARTH approximation
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