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Szsz-Mirakjan型算子的导数与函数的光滑性(英文)
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作者 熊静宜 杨汝月 曹飞龙 《海南大学学报(自然科学版)》 CAS 2003年第3期207-214,共8页
利用r阶Ditzian Totik模ωrφλ(f,t)(r∈N,0≤λ≤1),得到关于Sz sz Mirakjan型算子导数的特征刻画定理,建立了算子导数与函数光滑性之间的点态及整体关系,并统一了这2种结果.
关键词 算子逼近 Szász-Mirakjan型算子 算子导数 函数光滑性 点态 正定理 逆定理
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酉群上Jackson型算子逼近具有可变光滑性函数
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作者 俞国华 李世雄 《安徽大学学报(自然科学版)》 CAS 1995年第3期18-22,共5页
本文讨论了用酉群上的Jackson型算子对酉群上具有可变光滑性函数的逼近问题,给出了逼近阶的估计。
关键词 酉群 可变光滑性函数 雅可松算子 逼近
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连续函数图象的精细计盒维数及其刻划 被引量:5
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作者 江惠坤 《工程图学学报》 CSCD 1999年第2期21-26,共6页
将分形理论中的一个重要概念计盒维数推广为精细计盒维数,讨论此定义的等价表示。并且给出了Rn上连续函数图象的精细计盒维数用函数空间刻划的充要条件。
关键词 精细计盒维数 光滑性函数空间 维数 分形
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关于广义Baskakov算子的高阶点态导数 被引量:1
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作者 王丽 薛银川 《海南大学学报(自然科学版)》 CAS 2003年第3期227-231,共5页
讨论广义Baskakov算子借助Ditian Totik光滑模给出的高阶导数的特征刻画,统一了点态和整体的2种结果.
关键词 广义BASKAKOV算子 高阶点态导数 Ditian—Totik光滑 正逆定理 函数光滑性 算子逼近
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Bernstein-Durrmeyer算子导数的等价刻划 被引量:1
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作者 丁春梅 《甘肃工业大学学报》 北大核心 2002年第1期110-113,共4页
研究了Bernstein-Durrmeyer算子高阶导数与函数光滑性之间的等价关系,用Ditzian-Totik模刻划该算子点态和整体导数的特征,得到了一个等价刻划定理,所得结果统一了该算子导数的点态和整体两种渐近性态的等价表征.
关键词 BERNSTEIN-DURRMEYER算子 导数 光滑 等价刻划 函数光滑性
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On n-K Width of Certain Function Classes Defined by Linear Differential Operators in L_2 Space
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作者 吴嘎日迪 包那 《Chinese Quarterly Journal of Mathematics》 CSCD 1999年第4期27-31, ,共5页
Let M(u) be an N function, A=D r+∑r-1k=0a k(x)D k a linear differential operator and W M(A) the Sobolev Orlicz class defined by M(u) and A. In this paper we give the asymptotic estimates... Let M(u) be an N function, A=D r+∑r-1k=0a k(x)D k a linear differential operator and W M(A) the Sobolev Orlicz class defined by M(u) and A. In this paper we give the asymptotic estimates of the n K width d n(W M(A),L 2[0,1]) . 展开更多
关键词 linear operator smooth function class WIDTH
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On n-K Width of Certain Function Classes Defined by Linear Differential Operators in L2 Space 被引量:2
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作者 吴嘎日迪 包那 《Chinese Quarterly Journal of Mathematics》 CSCD 1999年第4期27-31,共页
Let M(u) be an N function, A=D r+∑r-1k=0a k(x)D k a linear differential operator and W M(A) the Sobolev Orlicz class defined by M(u) and A. In this paper we give the asymptotic estimates... Let M(u) be an N function, A=D r+∑r-1k=0a k(x)D k a linear differential operator and W M(A) the Sobolev Orlicz class defined by M(u) and A. In this paper we give the asymptotic estimates of the n K width d n(W M(A),L 2[0,1]) . 展开更多
关键词 linear operator smooth function class WIDTH
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分形中计盒维数的一种推广 被引量:2
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作者 陶爱斌 戴美凤 《华东船舶工业学院学报》 EI 2001年第4期78-81,共4页
将分形理论中的一个重要概念计盒维数推广到多重情况 ,给出了精细 (下 )计盒维数的定义及等价表示 ,且讨论了光滑性函数空间精细 (下 )计盒维数的表示。
关键词 多重维测度 精细(下)计盒维数 等价表示 光滑性函数空间 分理理论
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多元Stancu多项式与连续模 被引量:6
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作者 曹飞龙 《数学学报(中文版)》 SCIE CSCD 北大核心 2005年第1期51-62,共12页
本文研究单纯形上多元Stancu多项式与连续模之间的关系,证明了Stancu多项式具有保持连续模的性质,推广了一元Bernstein多项式的相应结果.同时,利用多元函数的Ditzian-Totik连续模估计Stancu多项式逼近多元连续函数速度的上界和下界,得... 本文研究单纯形上多元Stancu多项式与连续模之间的关系,证明了Stancu多项式具有保持连续模的性质,推广了一元Bernstein多项式的相应结果.同时,利用多元函数的Ditzian-Totik连续模估计Stancu多项式逼近多元连续函数速度的上界和下界,得到一个使得逼近速度为O(n-a)(0<a<1)的关于函数光滑性的充要条件. 展开更多
关键词 连续模 多项式逼近 逼近速度 函数光滑性 模估计 上界 下界 BERNSTEIN多项式 单纯形 连续函数
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基于空间相机TDI传感器重叠区图像的像移测量方法中的多解性研究 被引量:3
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作者 刘海秋 王栋 徐抒岩 《光学学报》 EI CAS CSCD 北大核心 2014年第12期114-120,共7页
针对基于时间延迟积分(TDI)传感器重叠区图像的像移测量方法的多解性问题,提出了以光滑性评价函数最小值为像移解的多解去除方法。根据像移测量原理,探析了像移测量方法的多解性;新增了光滑性评价函数,评价像移曲线的光滑性;以共轭梯度... 针对基于时间延迟积分(TDI)传感器重叠区图像的像移测量方法的多解性问题,提出了以光滑性评价函数最小值为像移解的多解去除方法。根据像移测量原理,探析了像移测量方法的多解性;新增了光滑性评价函数,评价像移曲线的光滑性;以共轭梯度法求解的光滑性评价函数的最小解为像移解,实现从多个伪解中提取真实解;实验结果表明像移测量结果唯一,且测量误差为0.13pixel,证明了以光滑性评价函数最小值为像移解的多解去除法的有效性。 展开更多
关键词 传感器 空间相机 像移测量 多解性 光滑性评价函数 共轭梯度法
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New Monotonicity Formulae for Semi-linear Ellipti and Parabolic Systems
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作者 Li MA Xianfa SONG Lin ZHAO 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2010年第3期411-432,共22页
The authors establish a general monotonicity formula for the following elliptic system △ui+fi(x,ui,…,um)=0 in Ω,where Ω belong to belong to R^n is a regular domain, (fi(x, u1,... ,um)) = △↓F(x,→↑u), F... The authors establish a general monotonicity formula for the following elliptic system △ui+fi(x,ui,…,um)=0 in Ω,where Ω belong to belong to R^n is a regular domain, (fi(x, u1,... ,um)) = △↓F(x,→↑u), F(x,→↑u ) is a given smooth function of x ∈ R^n and →↑u = (u1,…,um) ∈ R^m. The system comes from understanding the stationary case of Ginzburg-Landau model. A new monotonicity formula is also set up for the following parabolic systemδtui-△ui-fi(x,ui,…,um)=0 in(ti,t2)×R^n,where t1 〈 t2 are two constants, (fi(x,→↑u ) is given as above. The new monotonicity formulae are focused more attention on the monotonicity of nonlinear terms. The new point of the results is that an index β is introduced to measure the monotonicity of the nonlinear terms in the problems. The index β in the study of monotonieity formulae is useful in understanding the behavior of blow-up sequences of solutions. Another new feature is that the previous monotonicity formulae are extended to nonhomogeneous nonlinearities. As applications, the Ginzburg-Landau model and some different generalizations to the free boundary problems are studied. 展开更多
关键词 Elliptic systems Parabolic system Monotonicity formula Ginzburg-Landau model
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A SIMPLE SMOOTH EXACT PENALTY FUNCTION FOR SMOOTH OPTIMIZATION PROBLEM 被引量:3
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作者 Shujun LIAN Liansheng ZHANG 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2012年第3期521-528,共8页
For smooth optimization problem with equMity constraints, new continuously differentiable penalty function is derived. It is proved exact in the sense that local optimizers of a nonlinear program are precisely the opt... For smooth optimization problem with equMity constraints, new continuously differentiable penalty function is derived. It is proved exact in the sense that local optimizers of a nonlinear program are precisely the optimizers of the associated penalty function under some nondegeneracy assumption. It is simple in the sense that the penalty function only includes the objective function and constrained functions, and it doesn't include their gradients. This is achieved by augmenting the dimension of the program by a variable that controls the weight of the penalty terms. 展开更多
关键词 Constrained optimization exact penalty function smooth penalty function.
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Sieve M-estimator for a semi-functional linear model 被引量:3
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作者 HUANG LeLe WANG HuiWen +1 位作者 CUI HengJian WANG SiYang 《Science China Mathematics》 SCIE CSCD 2015年第11期2421-2434,共14页
We propose sieve M-estimator for a semi-functional linear model in which the scalar response is explained by a linear operator of functional predictor and smooth functions of some real-valued random variables.Spline e... We propose sieve M-estimator for a semi-functional linear model in which the scalar response is explained by a linear operator of functional predictor and smooth functions of some real-valued random variables.Spline estimators of the functional coefficient and the smooth functions are considered,and by selecting appropriate knot numbers the optimal convergence rate and the asymptotic normality can be obtained under some mild conditions.Some simulation results and a real data example are presented to illustrate the performance of our estimation method. 展开更多
关键词 functional linear model sieve estimator SPLINE knot number convergence rate
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An L_2-theory for a class of SPDEs driven by Lévy processes
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作者 CHEN Zhen-Qing KIM KyeongHun 《Science China Mathematics》 SCIE 2012年第11期2233-2246,共14页
In this paper we present an L2-theory for a class of stochastic partial differential equations driven by Levy processes. The coefficients of the equations are random functions depending on time and space variables, an... In this paper we present an L2-theory for a class of stochastic partial differential equations driven by Levy processes. The coefficients of the equations are random functions depending on time and space variables, and no smoothness assumption of the coefficients is assumed. 展开更多
关键词 stochastic parabolic partial differential equations Levy processes L2-theory
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Method of characteristics and first integrals for systems of quasi-linear partial differential equations of first order 被引量:1
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作者 HAN ChongKyu PARK JongDo 《Science China Mathematics》 SCIE CSCD 2015年第8期1665-1676,共12页
Given a set of independent vector fields on a smooth manifold, we discuss how to find a function whose zero-level set is invariant under the flows of the vector fields. As an application, we study the solvability of o... Given a set of independent vector fields on a smooth manifold, we discuss how to find a function whose zero-level set is invariant under the flows of the vector fields. As an application, we study the solvability of overdetermined partial differential equations: Given a system of quasi-linear PDEs of first order for one unknown function we find a necessary and sufficient condition for the existence of solutions in terms of the second jet of the coefficients. This generalizes to certain quasi-linear systems of first order for several unknown functions. 展开更多
关键词 overdetermined PDE system quasi-linear first order PDEs first integrals Pfai:fian systems Frobe-nius theorem
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Nonsmooth Semi-Infinite Minmax Programming Involving Generalized(Φ, ρ)-Invexity
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作者 UPADHYAY B B MISHRA S K 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2015年第4期857-875,共19页
This paper introduces some new generalizations of the concept of (~, p)-invexity for non- differentiable locally Lipschitz functions using the tools of Clarke subdifferential. These functions are used to derive the ... This paper introduces some new generalizations of the concept of (~, p)-invexity for non- differentiable locally Lipschitz functions using the tools of Clarke subdifferential. These functions are used to derive the necessary and sufficient optimality conditions for a class of nonsmooth semi-infinite minmax programming problems, where set of restrictions are indexed in a compact set. Utilizing the sufficient optimality conditions, the authors formulate three types of dual models and establish weak and strong duality results. The results of the paper extend and unify naturally some earlier results from the literature. 展开更多
关键词 Duality generalized invexity locally Lipschitz functions minmax programming semi-infinite programming.
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GLOBAL CONVERGENCE OF A CLASS OF SMOOTH PENALTY METHODS FOR SEMI-INFINITE PROGRAMMING
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作者 Changyu WANG Haiyan ZHANG Fang LIU 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2011年第4期769-783,共15页
For the semi-infinite programming (SIP) problem, the authors first convert it into an equivalent nonlinear programming problem with only one inequality constraint by using an integral function, and then propose a sm... For the semi-infinite programming (SIP) problem, the authors first convert it into an equivalent nonlinear programming problem with only one inequality constraint by using an integral function, and then propose a smooth penalty method based on a class of smooth functions. The main feature of this method is that the global solution of the penalty function is not necessarily solved at each iteration, and under mild assumptions, the method is always feasible and efficient when the evaluation of the integral function is not very expensive. The global convergence property is obtained in the absence of any constraint qualifications, that is, any accumulation point of the sequence generated by the algorithm is the solution of the SIP. Moreover, the authors show a perturbation theorem of the method and obtain several interesting results. Furthermore, the authors show that all iterative points remain feasible after a finite number of iterations under the Mangasarian-Fromovitz constraint qualification. Finally, numerical results are given. 展开更多
关键词 Global convergence semi-infinite programming smooth penalty function perturbation function.
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