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BOUNDEDNESS OF VARIATION OPERATORS ASSOCIATED WITH THE HEAT SEMIGROUP GENERATED BY HIGH ORDER SCHRODINGER TYPE OPERATORS 被引量:3
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作者 Suying LIU Chao ZHANG 《Acta Mathematica Scientia》 SCIE CSCD 2020年第5期1215-1228,共14页
In this article,we derive the Lp-boundedness of the variation operators associated with the heat semigroup which is generated by the high order Schrodinger type operator(—Δ)^2+V%2 in R%n(n≥5)with V being a nonnegat... In this article,we derive the Lp-boundedness of the variation operators associated with the heat semigroup which is generated by the high order Schrodinger type operator(—Δ)^2+V%2 in R%n(n≥5)with V being a nonnegative potential satisfying the reverse Holder inequality.Furt her more,we prove the boundedness of the variation operators on associated Morrey spaces.In the proof of the main results,we always make use of the variation inequalities associated with the hea t semigroup genera ted by the biharmonic operator(-Δ)2. 展开更多
关键词 Variation operators high order Schrodinger type operators heat semigroup
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A NOTE ON MEYER-KONIG AND ZELLER OPERATORS FOR FUNCTIONS OF BOUNDED VARIATION 被引量:2
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作者 Vijay Gupta (Netaji Subhas Institute of Technology, India) 《Approximation Theory and Its Applications》 2002年第3期99-102,共4页
In the present note we give the correct and improved estimate on the rate of convergence of integrated Meyer-Konig and Zetter operators for function of bounded variation.
关键词 RATE In MATH A NOTE ON MEYER-KONIG AND ZELLER operatorS FOR FUNCTIONS OF BOUNDED VARIATION
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A SHARP ESTIMATE ON THE DEGREE OF APPROXIMATION TO FUNCTIONS OF BOUNDED VARIATION BY CERTAIN OPERATORS 被引量:1
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作者 Vijay Gupta 《Analysis in Theory and Applications》 1995年第3期106-107,共2页
Recently Guo introduced integrated Meyer -Konig and Zeller operators and studied the rate of convergence for function of bounded variation. In this note we give a sharp estimate for these operators.
关键词 A SHARP ESTIMATE ON THE DEGREE OF APPROXIMATION TO FUNCTIONS OF BOUNDED VARIATION BY CERTAIN operatorS
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A Four-Dimensional Variational System for Skillful Operational Prediction of Convective Storms
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作者 Nathan SNOOK Qinghong ZHANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2016年第10期1102-1103,共2页
Forecasting convective storms using NWP models is an important goal and a highly active area of ongoing research. Skillful and reliable NWP of convective storms could allow for severe weather warnings with longer lead... Forecasting convective storms using NWP models is an important goal and a highly active area of ongoing research. Skillful and reliable NWP of convective storms could allow for severe weather warnings with longer lead times, as opera- tional forecasters begin to incorporate convective-scale fore- casts into severe weather forecast operations (Stensrud et al., 2009, 2013). This would then provide vulnerable individuals and industries with more time to seek shelter and/or mitigate the impact of severe weather hazards. 展开更多
关键词 VDRAS A Four-Dimensional variational System for Skillful Operational Prediction of Convective Storms NWP
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Symbolic Macromodeling for Statistical Simulation of Operational Amplifiers
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作者 Lan-Lan Dong Guo-Yong Shi Jian-Dong Cheng 《Journal of Electronic Science and Technology》 CAS 2013年第3期272-276,共5页
Symbolic circuit simulator is traditionally applied to the small-signal analysis of analog circuits. This paper establishes a symbolic behavioral macromodeling method applicable to both small-signal and large-signal a... Symbolic circuit simulator is traditionally applied to the small-signal analysis of analog circuits. This paper establishes a symbolic behavioral macromodeling method applicable to both small-signal and large-signal analysis of general two-stage operational amplifiers (op-amps). The proposed method creates a two-pole parametric macromodel whose parameters are analytical functions of the circuit element parameters generated by a symbolic circuit simulator. A moment matching technique is used in deriving the analytical model parameter. The created parametric behavioral model can be used for op-amps performance simulation in both frequency and time domains. In particular, the parametric models are highly suited for fast statistical simulation of op-amps in the time-domain. Experiment results show that the statistical distributions of the op-amp slew and settling time characterized by the proposed model agree well with the transistor-level results in addition to achieving significant speedup. 展开更多
关键词 Index Terms---Analog behavioral model large-signalanalysis moment matching operational amplifiers process variation statistical analysis symbolic analysis.
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Discrete Fractional Birkhoff Equations in Terms of Time Scales
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作者 宋传静 张毅 《Journal of Donghua University(English Edition)》 EI CAS 2017年第3期430-435,共6页
In order to study discrete fractional Birkhoff equations for Birkhoffian systems,the method of isochronous variational principle is used in this paper. Discrete fractional Pfaff-Birkhoff principle in terms of time sca... In order to study discrete fractional Birkhoff equations for Birkhoffian systems,the method of isochronous variational principle is used in this paper. Discrete fractional Pfaff-Birkhoff principle in terms of time scales is presented. Discrete fractional Birkhoff equations with left and right discrete operators of Riemann-Liouville type are established and some special cases including classical discrete Birkhoff equations,discrete fractional Hamilton equations and discrete fractional Lagrange equations are discussed. Finally,an example is devoted to illustrate the results. 展开更多
关键词 Liouville fractional Riemann operators variational devoted calculus illustrate scales integer
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Operators Related to Truncated Hilbert Transforms on H1 被引量:2
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作者 Hong Hai LIU 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2017年第7期1011-1020,共10页
Abstract In this paper, we give counterexamples to show that variation and oscillation operators related to rough truncations of the Hilbert transform are not bounded from H1 to L1, and prove variation, oscillation an... Abstract In this paper, we give counterexamples to show that variation and oscillation operators related to rough truncations of the Hilbert transform are not bounded from H1 to L1, and prove variation, oscillation and A-jump operators related to smooth truncations are bounded from H1 to L1. 展开更多
关键词 Variation operator oscillation operator A-jump operator the Hilbert transform Hardyspace
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The Connection Between the Metric and Generalized Projection Operators in Banach Spaces 被引量:4
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作者 Yakov ALBER Jin Lu LI 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2007年第6期1109-1120,共12页
In this paper we study the connection between the metric projection operator PK : B →K, where B is a reflexive Banach space with dual space B^* and K is a non-empty closed convex subset of B, and the generalized pr... In this paper we study the connection between the metric projection operator PK : B →K, where B is a reflexive Banach space with dual space B^* and K is a non-empty closed convex subset of B, and the generalized projection operators ∏K : B → K and πK : B^* → K. We also present some results in non-reflexive Banach spaces. 展开更多
关键词 Banach spaces normalized duality mappings metric and generalized projection operators variational inequalities minimization problems closed and convex subsets and cones
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Variation Inequalities Related to Schr?dinger Operators on Morrey Spaces 被引量:1
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作者 Jing ZHANG Huoxiong WU 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2018年第6期973-988,共16页
The authors establish the boundedness of the variation operators associated with the heat semigroup, Riesz transforms and commutators generated by the Riesz transforms and BMO-type functions in the Schrodinger setting... The authors establish the boundedness of the variation operators associated with the heat semigroup, Riesz transforms and commutators generated by the Riesz transforms and BMO-type functions in the Schrodinger setting on the Morrey spaces. 展开更多
关键词 Schrodinger operators Variation operators Heat semigroups Riesz transforms COMMUTATORS Morrey spaces
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Variation operators for singular integrals and their commutators on weighted Morrey spaces and Sobolev spaces
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作者 Feng Liu Peng Cui 《Science China Mathematics》 SCIE CSCD 2022年第6期1267-1292,共26页
In this paper,we investigate the boundedness and compactness for variation operators of CalderónZygmund singular integrals and their commutators on weighted Morrey spaces and Sobolev spaces.To be precise,letρ>... In this paper,we investigate the boundedness and compactness for variation operators of CalderónZygmund singular integrals and their commutators on weighted Morrey spaces and Sobolev spaces.To be precise,letρ>2 and K be a standard Calderón-Zygmund kernel.Denote by V_(ρ)(T_(K))and V_(ρ)(T_(K,b)^(m))(m≥1)theρ-variation operators of Calderón-Zygmund singular integrals and their m-th iterated commutators,respectively.By assuming that V_(ρ)(T_(K))satisfies an a priori estimate,i.e.,the map V_(ρ)(T_(K)):L^(p0)(R^(n))→L^(p0)(R^(n))is bounded for some p0∈(1,∞),the bounds for V_(ρ)(T_(K))and V_(ρ)(T_(K,b)^(m))on weighted Morrey spaces and Sobolev spaces are established.Meanwhile,the compactness properties of V_(ρ)(T_(K,b)^(m))on weighted Lebesgue and Morrey spaces are also discussed.As applications,the corresponding results for the Hilbert transform,the Hermite Riesz transform,Riesz transforms and rough singular integrals as well as their commutators on the above function spaces are presented. 展开更多
关键词 variation operator Calderón-Zygmund singular integral COMMUTATOR weighted Morrey space Sobolev space
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Oscillation and variation for Riesz transform in setting of Bessel operators on H1 and BMO
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作者 Xiaona CUI Jing ZHANG 《Frontiers of Mathematics in China》 SCIE CSCD 2020年第4期617-647,共31页
Letλ〉0,and let the Bessel operator△λ:=-d2/dx2-2λ/x d/dx defined on R+:=(0,∞).We show that the oscillation andρ-variation operators of the Riesz transform R△λassociated with△λare bounded on BMO(R+,dmλ),wher... Letλ〉0,and let the Bessel operator△λ:=-d2/dx2-2λ/x d/dx defined on R+:=(0,∞).We show that the oscillation andρ-variation operators of the Riesz transform R△λassociated with△λare bounded on BMO(R+,dmλ),whereρ>2 and dmλ=x2λdx.Moreover,we construct a(1,∞)△λ-atom as a counterexample to show that the oscillation andρ-variation operators of R△λare not bounded from to L1(R+,dmλ).Finally,we prove that the oscillation and theρ-variation operators for the smooth truncations associated with Bessel operators R~△λare bounded from H1(R+:dmλ)to L1(R+,dmλ). 展开更多
关键词 Oscillation operator variation operator Bessel operator
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Weighted Variation Inequalities for Singular Integrals and Commutators in Rearrangement Invariant Banach and Quasi-Banach Spaces
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作者 Jia Wei TAN Qing Ying XUE 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2023年第7期1389-1413,共25页
In order to study the boundedness of some operators in general function spaces which include Lorentz spaces and Orlicz spaces as special examples,Lorentz introduced a new space called rearrangement invariant Banach fu... In order to study the boundedness of some operators in general function spaces which include Lorentz spaces and Orlicz spaces as special examples,Lorentz introduced a new space called rearrangement invariant Banach function spaces,denoted by RIBFS.It is shown in this paper that variation operators of singular integrals and their commutators are bounded on RIBFS whenever the kernels satisfy the L~r-H?rmander conditions.Moreover,we obtain some quantitative weighted bounds in the quasi-Banach spaces and modular inequalities for above variation operators and their commutators. 展开更多
关键词 Variation operators singular integrals COMMUTATORS sparse operators rearrangement invariant Banach function spaces
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Regional, Single Point, and Global Blow-Up for the Fourth-Order Porous Medium Type Equation with Source
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作者 GALAKTIONV V.A. 《Journal of Partial Differential Equations》 2010年第2期105-146,共42页
Blow-up behaviour for the fourth-order quasilinear porous medium equation with source,ut=-(|u|^nu)xxxx+|u|^p-1u in R×R+,where n 〉 0, p 〉 1, is studied. Countable and finite families of similarity blow-u... Blow-up behaviour for the fourth-order quasilinear porous medium equation with source,ut=-(|u|^nu)xxxx+|u|^p-1u in R×R+,where n 〉 0, p 〉 1, is studied. Countable and finite families of similarity blow-up patterns of the form us(x,t)=(T-t)^-1/p-1f(y),where y=x/(T-t)^β' β=p-(n+1)/4(p-1),which blow-up as t → T^- 〈∞ are described. These solutions explain key features of regional (for p = n+1), single point (for p 〉 n+1), and global (for p ∈ (1,n+1))blowup. The concepts and various variational, bifurcation, and numerical approaches for revealing the structure and multiplicities of such blow-up patterns are presented. 展开更多
关键词 Higher-order quasilinear porous medium parabolic equation finite propagation BLOW-UP similarity solutions variational operators branching.
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EFFICIENT BOX-CONSTRAINED TV-TYPE-l^1 ALGORITHMS FOR RESTORING IMAGES WITH IMPULSE NOISE 被引量:6
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作者 Liyan Ma Michael K. Ng +1 位作者 Jian Yu Tieyong Zeng 《Journal of Computational Mathematics》 SCIE CSCD 2013年第3期249-270,共22页
In this paper, we study the restoration of images simultaneously corrupted by blur and impulse noise via variational approach with a box constraint on the pixel values of an image. In the literature, the TV-l^1 variat... In this paper, we study the restoration of images simultaneously corrupted by blur and impulse noise via variational approach with a box constraint on the pixel values of an image. In the literature, the TV-l^1 variational model which contains a total variation (TV) regularization term and an l^1 data-fidelity term, has been proposed and developed. Several numerical methods have been studied and experimental results have shown that these methods lead to very promising results. However, these numerical methods are designed based on approximation or penalty approaches, and do not consider the box constraint. The addition of the box constraint makes the problem more difficult to handle. The main contribution of this paper is to develop numerical algorithms based on the derivation of exact total variation and the use of proximal operators. Both one-phase and two-phase methods are considered, and both TV and nonlocal TV versions are designed. The box constraint [0, 1] on the pixel values of an image can be efficiently handled by the proposed algorithms. The numerical experiments demonstrate that the proposed methods are efficient in computational time and effective in restoring images with impulse noise. 展开更多
关键词 Image restoration Impulse noise Total variation Nonlocal total variation Proximal operators.
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Optimal Operation of Energy Internet Based on User Electricity Anxiety and Chaotic Spatial Variation Particle Swarm Optimization 被引量:1
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作者 Dongsheng Yang Qianqian Chong +1 位作者 Bo Hu Min Ma 《Tsinghua Science and Technology》 SCIE EI CAS CSCD 2018年第3期243-253,共11页
Ignoring load characteristics and not considering user feeling with regard to the optimal operation of Energy Internet(EI) results in a large error in optimization. Thus, results are not consistent with the actual o... Ignoring load characteristics and not considering user feeling with regard to the optimal operation of Energy Internet(EI) results in a large error in optimization. Thus, results are not consistent with the actual operating conditions. To solve these problems, this paper proposes an optimization method based on user Electricity Anxiety(EA) and Chaotic Space Variation Particle Swarm Optimization(CSVPSO). First, the load is divided into critical load, translation load, shiftable load, and temperature load. Then, on the basis of the different load characteristics,the concept of the user EA degree is presented, and the optimization model of the EI is provided. This paper also presents a CSVPSO algorithm to solve the optimization problem because the traditional particle swarm optimization algorithm takes a long time and particles easily fall into the local optimum. In CSVPSO, the particles with lower fitness value are operated by using cross operation, and velocity variation is performed for particles with a speed lower than the setting threshold. The effectiveness of the proposed method is verified by simulation analysis.Simulation results show that the proposed method can be used to optimize the operation of EI on the basis of the full consideration of the load characteristics. Moreover, the optimization algorithm has high accuracy and computational efficiency. 展开更多
关键词 Electricity Anxiety(EA) Energy Internet(EI) chaotic spatial variation particle swarm optimization optimal operation
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