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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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Distribution function estimates by Wasserstein metric and Bernstein approximation for C^(-1) functions 被引量:2
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作者 WU Zong-min TIAN Zheng 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2015年第2期141-150,共10页
The aim of the paper is to estimate the density functions or distribution functions measured by Wasserstein metric, a typical kind of statistical distances, which is usually required in the statistical learning. Based... The aim of the paper is to estimate the density functions or distribution functions measured by Wasserstein metric, a typical kind of statistical distances, which is usually required in the statistical learning. Based on the classical Bernstein approximation, a scheme is presented. To get the error estimates of the scheme, the problem turns to estimating the L1 norm of the Bernstein approximation for monotone C-1 functions, which was rarely discussed in the classical approximation theory. Finally, we get a probability estimate by the statistical distance. 展开更多
关键词 Wasserstein metric Bernstein approximation L1 norm approximation confidence interval
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RADIATIVE TRANSPORT IN THE DELTA-P1 APPROXIMATION FOR LAMINAR OPTICAL TOMOGRAPHY
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作者 BAOHONG YUAN 《Journal of Innovative Optical Health Sciences》 SCIE EI CAS 2009年第2期149-163,共15页
To provide a computational efficient forward model with moderate accuracy for rapid 3D optical tomography in small volumes,radiative transport in the delta-P1 approximation combined with the approximation of the recip... To provide a computational efficient forward model with moderate accuracy for rapid 3D optical tomography in small volumes,radiative transport in the delta-P1 approximation combined with the approximation of the reciprocity was examined.Perturbations of optical signals caused by absorption and fluorescence heterogeneities submerged in a resin-based liquid phantom with background parameters close to rat brain tissues were measured using a recently constructed laminar optical tomography system.These measured perturbations were used to examine the theoretically calculated fluence perturbations based on the delta-P1 approximation and the reciprocity approximation.Results show that the errors between the predicted and measured data are acceptable,especially for fluorescence perturbations. 展开更多
关键词 Photon migration TOMOGRAPHY fluorescence delta-P1 approximation reciprocity approximation.
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APPROXIMATION PROPERTIES OF LAGRANGE INTERPOLATION POLYNOMIAL BASED ON THE ZEROS OF (1-x^2)cosnarccosx
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作者 Laiyi Zhu 《Analysis in Theory and Applications》 2006年第2期183-194,共12页
We study some approximation properties of Lagrange interpolation polynomial based on the zeros of (1-x^2)cosnarccosx. By using a decomposition for f(x) ∈ C^τC^τ+1 we obtain an estimate of ‖f(x) -Ln+2(f, ... We study some approximation properties of Lagrange interpolation polynomial based on the zeros of (1-x^2)cosnarccosx. By using a decomposition for f(x) ∈ C^τC^τ+1 we obtain an estimate of ‖f(x) -Ln+2(f, x)‖ which reflects the influence of the position of the x's and ω(f^(r+1),δ)j,j = 0, 1,... , s,on the error of approximation. 展开更多
关键词 Lagrange interpolation polynomial zeros of 1 -x^2)cos n arccosx piecewise smooth functions error of approximation
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APPROXIMATION BY KANTOROVICH-BERNSTEIN POLYNOMIALS IN L_p(0
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作者 G.T.Tachev 《Analysis in Theory and Applications》 1992年第3期38-50,共13页
The purpose of the present paper is to evaluate the error of the approximation of the func- tion fL_1[0,1]by Kantorovich-Bernstein polynomials in L_p-metric(0<p<1).
关键词 METRIC p<1 approximation BY KANTOROVICH-BERNSTEIN POLYNOMIALS IN L_p
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L_p(1≤p≤∞) APPROXIMATION BY AN n-DIMENSIONAL SUBSPACE ON A SET OF n+1 POINTS
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作者 史应光 《Acta Mathematica Scientia》 SCIE CSCD 1993年第4期430-436,共7页
Some new characterizations and immediate explicit expressions of best L(1≤p≤∞) approximation and their deviations by an n-dimensional subspace on a set of n+1 points are given.
关键词 approximation BY AN n-DIMENSIONAL SUBSPACE ON A SET OF n+1 POINTS L_p ID Case
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The Mixed Spin-1/2 and Spin-1 Ising–Heisenberg Model in the Mean-Field Approximation: a New Approach
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作者 Erhan Albayrak 《Chinese Physics Letters》 SCIE CAS CSCD 2018年第3期84-88,共5页
Thermodynamic properties of the mixed spin-1 and spin-1/2 Ising-Heisenberg model are studied on a honeycomb lattice using a new approach in the mean-field approximation to analyze the effects of longitudinal Dz and tr... Thermodynamic properties of the mixed spin-1 and spin-1/2 Ising-Heisenberg model are studied on a honeycomb lattice using a new approach in the mean-field approximation to analyze the effects of longitudinal Dz and transverse Dx crystal fields. The phase diagrams are calculated in detail by studying the thermal variations of the order parameters, i.e., magnetizations and quadrupole moments, and compared with the literature to assess the reliability of the new approach. It is found that the model yields both second- and first-order phase transitions, and tricritical points. The compensation behavior of the model is also investigated for the sublattice magnetizations, and longitudinal and transverse quadrupolar moments. The latter type of compensation is observed in the literature but its possible importance is overlooked. 展开更多
关键词 Heisenberg Model in the Mean-Field approximation The Mixed Spin-1/2 and Spin-1 Ising a New Approach
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APPROXIMATION BY FABER-LAURENT RATIONAL FUNCTIONS IN THE MEAN OF FUNCTIONS OF CLASS LP(T) WITH 1
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作者 A. Cavus D. M. Israfilov 《Analysis in Theory and Applications》 1995年第1期105-118,共14页
Let Γ be a regular curve and Lp (Γ), 1<p<+∞. be the class of all complex - valued functions f de-fined on Γ which are such that |f|p is mtegrabie in sense of Lebesgue. In this work, we define the k th p-Fabc... Let Γ be a regular curve and Lp (Γ), 1<p<+∞. be the class of all complex - valued functions f de-fined on Γ which are such that |f|p is mtegrabie in sense of Lebesgue. In this work, we define the k th p-Fabcrpolynomial F k,p (z),the kth p-Faber principle part F k.p (1/z) for Γ , and defined the nth p-Fcber- Laurent rational function Rn.p (f, z) and p- generalized modulus of continuity Ωp(f, t) of a function f of Lp(Γ) We inves-tigate some properties of Fk,p (z) and Fk.p (1/z). And then we prove a direct theorem characterizing the degree of approximation with respect to Ω (. , t) in the mean of functions of Lp(Γ) by the rational junctions Rn.p (. . z). 展开更多
关键词 approximation BY FABER-LAURENT RATIONAL FUNCTIONS IN THE MEAN OF FUNCTIONS OF CLASS LP WITH 1 Rational
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On Converse Theorem of Best Approximation by Polynomials in Bergman Spaces H_q^p(p>0,q>1)
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作者 邢富冲 《Chinese Quarterly Journal of Mathematics》 CSCD 1993年第4期89-98,共10页
A Bernstein type theorem and a converse theorem of best approximation by polynomials in Bergman spaces Hq^p(p>0,q>1) are proved.Some proofs and results in [1] are in proved.
关键词 Bergman spaces H_q^p(p>0 q>1) integral modulus of continuity Bernsterin type inequality best approximation by polynomial converse theorem
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APPROXIMATE POWER OF HETEROSCEDASTICITY TEST IN NONLINEAR MODELS WITH ARIMA(0,1,0) ERRORS 被引量:1
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作者 Lin Jinguan Wei Bocheng Zhang Nansong 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2005年第4期423-430,共8页
This paper presents an approach for estimating power of the score test, based on an asymptotic approximation to the power of the score test under contiguous alternatives. The method is applied to the problem of power ... This paper presents an approach for estimating power of the score test, based on an asymptotic approximation to the power of the score test under contiguous alternatives. The method is applied to the problem of power calculations for the score test of heteroscedasticity in European rabbit data (Ratkowsky, 1983). Simulation studies are presented which indicate that the asymptotic approximation to the finite-sample situation is good over a wide range of parameter configurations. 展开更多
关键词 ARIMA (0 1 0) errors asymptotic approximation HETEROSCEDASTICITY local power nonlinear model score test.
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Approximation Theorem of K.Fan for Positive Mapping and Applications
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作者 朱江 《Chinese Quarterly Journal of Mathematics》 CSCD 1992年第1期55-59,共5页
In this paper, we investigate the validity of approximation theorm of K. Fan for a demicompact 1-set-contraction map defined on a closed ball,an annulus and a sphere in cones. From this, we improve all recent results ... In this paper, we investigate the validity of approximation theorm of K. Fan for a demicompact 1-set-contraction map defined on a closed ball,an annulus and a sphere in cones. From this, we improve all recent results of Lin [2]. As applications of our theorems, we discuss the existence of positive solutions to twopoint boundary value-problems of differential equations in Banach space. At the same time, the recent main results of (3) established by Guo Dajun are Generalized and supplemented. 展开更多
关键词 the approximation theorem of K. Fan demicompact 1-set-contraction maps twopoint boundary value-problems
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Truncated series solutions to the(2+1)-dimensional perturbed Boussinesq equation by using the approximate symmetry method
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作者 Xiao-Yu Jiao 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第10期123-129,共7页
In this paper, the(2+1)-dimensional perturbed Boussinesq equation is transformed into a series of two-dimensional(2 D) similarity reduction equations by using the approximate symmetry method. A step-by-step proce... In this paper, the(2+1)-dimensional perturbed Boussinesq equation is transformed into a series of two-dimensional(2 D) similarity reduction equations by using the approximate symmetry method. A step-by-step procedure is used to acquire Jacobi elliptic function solutions to these similarity equations, which generate the truncated series solutions to the original perturbed Boussinesq equation. Aside from some singular area, the series solutions are convergent when the perturbation parameter is diminished. 展开更多
关键词 approximate symmetry method (2+1)-dimensional perturbed Boussinesq equation series solutions convergence of series solutions
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广义Bézier曲面的G^(1)连续曲面逼近
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作者 杨耀源 杨勋年 《浙江大学学报(理学版)》 北大核心 2025年第6期719-727,765,共10页
广义Bézier曲面是一种新的N边形曲面,是张量积Bézier曲面的推广,具有简单的控制网格和良好的几何特征。为便于将广义Bézier曲面应用于CAD/CAM系统,给出了将广义Bézier曲面转化为标准Bézier曲面的近似算法。首... 广义Bézier曲面是一种新的N边形曲面,是张量积Bézier曲面的推广,具有简单的控制网格和良好的几何特征。为便于将广义Bézier曲面应用于CAD/CAM系统,给出了将广义Bézier曲面转化为标准Bézier曲面的近似算法。首先,采用N分裂方法将广义Bézier曲面的正N边形定义域分割成N个四边形子域;然后,对每个四边形子域构建满足G^(1)连续性条件的双五次Bézier曲面;最后,基于带线性约束的最小二乘法,优化双五次Bézier曲面的控制顶点,同时插值广义Bézier曲面的中心点以及边界曲线。该算法可将广义Bézier曲面近似转换为由N张双五次Bézier曲面G^(1)连续拼接构成的宏曲面片。宏曲面片采用标准CAD/CAM格式,可应用于以非均匀有理B样条(non-uniform rational B-splines,NURBS)为标准的CAD/CAM系统。数值结果表明,由该算法生成的宏曲面片在视觉上和数值上均能逼近广义Bézier曲面,并保持其几何特性。 展开更多
关键词 广义Bézier曲面 G^(1)连续 曲面逼近 宏曲面片
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An Efficient Quadratic Approximation of Simple Singular Solutions——Dedicated to Professor You Zhao-yong on the occasion of his 60-th birthday
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作者 Mei ZhenDepartment of MathematicsXi’an Jiaotong UniverityXi’an, Shaanxi ProvincePeople’s Republic of China 《工程数学学报》 CSCD 1991年第2期103-118,共16页
We consider a blockwise extended system and an efficient quadratically convergent Newton-like method for approximations of simple (cubic) singular solutions of nonlinear problems with sparse properties.
关键词 Blockwise extended system Newton-like method rank-1 corrections.
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Limit Laws for the Maximum Interpoint Distance under a 1-Dependent Assumption
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作者 Haibin ZHANG Yong ZHANG Xue DING 《Journal of Mathematical Research with Applications》 2025年第1期105-124,共20页
Let M_(n,p)=(X_(i,k))_(n×p)be an n×p random matrix whose p columns X^((1)),...,X^((p))are an n-dimensional i.i.d.random sample of size p from 1-dependent Gaussian populations.Instead of investigating the spe... Let M_(n,p)=(X_(i,k))_(n×p)be an n×p random matrix whose p columns X^((1)),...,X^((p))are an n-dimensional i.i.d.random sample of size p from 1-dependent Gaussian populations.Instead of investigating the special case where p and n are comparable,we consider a much more general case in which log n=o(p^(1/3)).We prove that the maximum interpoint distance Mn=max{|X_(i)-X_(j)|;1≤i<j≤n}converges to an extreme-value distribution,where X_(i)and X_(j)denote the i-th and j-th row of M_(n,p),respectively.The proofs are completed by using the Chen-Stein Poisson approximation method and the moderation deviation principle. 展开更多
关键词 maximum interpoint distance extreme-value distribution Chen-Stein Poisson approximation moderation deviation 1-dependent
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对称张量秩-1近似逆迭代算法
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作者 朱文凤 盛洲 《淮北师范大学学报(自然科学版)》 2025年第1期16-20,共5页
为得到对称张量秩-1近似分解,提出一个平移逆迭代算法。算法每步迭代子问题转化为计算一个线性方程组,选取适当平移参数保证线性方程组系数矩阵非奇异性,建立逆迭代算法全局收敛性。数值实验表明,算法在运行时间和迭代次数等方面具有较... 为得到对称张量秩-1近似分解,提出一个平移逆迭代算法。算法每步迭代子问题转化为计算一个线性方程组,选取适当平移参数保证线性方程组系数矩阵非奇异性,建立逆迭代算法全局收敛性。数值实验表明,算法在运行时间和迭代次数等方面具有较强竞争力。 展开更多
关键词 对称张量 秩-1近似 逆迭代 Z-特征对
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正则表达式分组的1/(1-1/k)-近似算法 被引量:12
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作者 柳厅文 孙永 +2 位作者 卜东波 郭莉 方滨兴 《软件学报》 EI CSCD 北大核心 2012年第9期2261-2272,共12页
对正则表达式集合进行分组是解决DFA状态膨胀问题的一种重要方法.已有的分组算法大都是启发式的或蛮力的,分组效果很差.分析了DFA状态膨胀的原因,总结了某些正则表达式间的冲突状况.证明了当冲突非负和冲突独立时,正则表达式集合的最优... 对正则表达式集合进行分组是解决DFA状态膨胀问题的一种重要方法.已有的分组算法大都是启发式的或蛮力的,分组效果很差.分析了DFA状态膨胀的原因,总结了某些正则表达式间的冲突状况.证明了当冲突非负和冲突独立时,正则表达式集合的最优k分组问题可归结为最大k割问题,从而说明该问题是NP-Hard的.基于局部搜索的思想,提出了一种分组算法GRELS来解决分组问题,并证明对最大k割问题,该算法的近似比是1/(1-1/k).与已有的分组算法相比,当分组数目相同时,GRELS算法分组结果的状态总数最少,并且集合发生变化时所需的更新时间最短. 展开更多
关键词 正则表达式 深度包检测 分组算法 局部搜索 1/(1-1/k)近似
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灰色NGM(1,1,k)模型背景值优化方法 被引量:16
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作者 童明余 周孝华 曾波 《控制与决策》 EI CSCD 北大核心 2017年第3期507-514,共8页
传统灰色NGM(1,1,k)模型的参数估计误差是导致该模型精度不稳定的重要因素,研究面向背景值优化基础上的参数估计方法是提高灰色模型性能的重要手段.通过积分变换,得到与NGM(1,1,k)模型白化方程匹配的灰色微分方程,推导出背景值优化公式... 传统灰色NGM(1,1,k)模型的参数估计误差是导致该模型精度不稳定的重要因素,研究面向背景值优化基础上的参数估计方法是提高灰色模型性能的重要手段.通过积分变换,得到与NGM(1,1,k)模型白化方程匹配的灰色微分方程,推导出背景值优化公式,从而构建背景值优化的新NGM(1,1,k)模型,并从理论上解释新模型能同时模拟严格齐次和非齐次指数增长序列的原因.进一步通过算例和实例验证了所提出的模型均能显著提高序列的模拟和预测精度. 展开更多
关键词 灰色系统 灰色预测模型 近似非齐次指数增长序列 NGM(1 1 k)模型 背景值
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基于改进的GM(1,1)-Markov链组合模型广东省单位GDP能耗预测 被引量:13
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作者 龙会典 严广乐 《数理统计与管理》 CSSCI 北大核心 2017年第2期200-207,共8页
本文以灰色系统理论的GM(1,1)模型和随机过程理论的Markov链模型为基础构建了一个动态GM(1,1)-Markov链组合预测模型。该模型同时利用了GM(1,1)模型对序列趋势因素良好的拟合能力和Markov链模型对残差序列信息的提取能力。为进一步提高... 本文以灰色系统理论的GM(1,1)模型和随机过程理论的Markov链模型为基础构建了一个动态GM(1,1)-Markov链组合预测模型。该模型同时利用了GM(1,1)模型对序列趋势因素良好的拟合能力和Markov链模型对残差序列信息的提取能力。为进一步提高该模型的预测精度,用泰勒(Taylor)近似方法和新信息优先的思想对该模型进行了改进。最后,以1991-2014年广东省单位GDP能耗数据实证了该模型的预测效果。 展开更多
关键词 单位GDP能耗 GM(1 1)-Markov链模型 泰勒近似方法
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一种基于盲运算的1比特压缩感知重建算法 被引量:2
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作者 闫斌 陈浩 +1 位作者 王文东 周小佳 《西南交通大学学报》 EI CSCD 北大核心 2015年第2期264-269,共6页
为了解决1比特压缩感知中符号匹配追踪算法(matching sign pursuit)在稀疏度未知的情况下不能自适应重构信号的问题,提出了向前/向后迭代符号匹配追踪算法(forward-backward matching sign pursuit,FBMSP).该算法以逐步逼近理论为核心,... 为了解决1比特压缩感知中符号匹配追踪算法(matching sign pursuit)在稀疏度未知的情况下不能自适应重构信号的问题,提出了向前/向后迭代符号匹配追踪算法(forward-backward matching sign pursuit,FBMSP).该算法以逐步逼近理论为核心,通过逐步扩大支撑集来扩大搜索范围,把相邻两次迭代的差值作为终止条件,在MSP算法模型下进行盲运算,以实现信号的重构.数值试验表明:在控制迭代系数α=8,β=1的情况下,FBMSP算法比传统的符号匹配追踪算法重构精度提高了3 d B,运算时间减少了40%. 展开更多
关键词 信号处理 压缩感知 逼近论 1比特 符号匹配追踪
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