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Commutant Lifting for Optimal Control of Time-varying Systems

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Communications in Mathematical Research 2012年第3期28卷 252-264页

作者： Liu LIU lu yu-feng School of Mathematical Sciences Dalian University of Technology Dalian Liaoning 116021

This paper uses the commutant lifting theorem for representations of the nest algebra to deal with the optimal control of infinite dimensional linear time- varying systems. We solve the model matching problem and a certain optimal feedback control problem, each of which corresponds with one type of four-block problem. We also obtain a new formula for the optimal performance and prove the existence of an optimal controller.

关键词： optimal control four block problem commutant lifting time-varying nest algebra

A Theorem of Nehari Type on the Bergman Space

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Communications in Mathematical Research 2009年第2期25卷 159-164页

作者： lu yu-feng YANG JUN Department of Applied Mathematics Dalian University of Technology Dalian 116024

In this paper we concern with the characterization of bounded linear operators S acting on the weighted Bergman spaces on the unit ball. It is shown that, if S satisfies the commutation relation STzi = Tzi（i =1,..,n）, where Tzi = zif and Tzi= P（zif） where P is the weighted Bergman projection, then S must be a Hankel operator.

关键词： Bergman space unit ball Hankel operator

Little Hankel Operators on the Weighted Bergman Space of the Unit Ball

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Communications in Mathematical Research 2010年第4期26卷 304-312页

作者： ZHANG KAN lu yu-feng LIU CHAO-MEI School of Mathematical Sciences Dalian University of TechnologyDalian116024 College of Sciences Shenyang Agricultural UniversityShenyang110866 School of Science Dalian Jiaotong UniversityDalian116028

In this paper we mainly consider little Hankel operators with squareintegrable symbols on the weighted Bergman spaces of the unit *** obtain that Schatten class of little Hankel operators is equivalent to Schatten class of positive Toeplitz operators under the conditions that SMO（f） ∈ L p/2 （B n,dλ） and 2 ≤ p ∞,which is very important to research the relation between Toeplitz operators and little Hankel operators.

关键词： weighted Bergman space little Hankel operator unit ball

Hierarchical Search Motion Estimation Algorithms for Real-time Video Coding

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通信学报 1998年第5期19卷 63-68页

作者： Zhang Yong yu lu Zhou feng Yao Qingdong (Zhejiang University, Hangzhou 310027) 浙江大学浙江杭州

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关键词：图像编码运动估计分层搜索视频通信

Simultaneous Stabilization for a Family of Plants

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Journal of Mathematical Research and Exposition 2008年第3期28卷 529-534页

作者： lu yu feng XU Xiao Ping Department of Applied Mathematics Dalian University of Technology Liaoning 116024 China

In this paper, we discuss the problem of simultaneous stabilization for plants more than three by using Youla parametrization and give a necessary and sufficient condition for simultaneous stabilization.

关键词： complete nest nest algebra linear system stabilizable.

Understanding the local structure and thermophysical behavior of Mg-La liquid alloys via machine learning potential

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International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 439-449页

作者： Jia Zhao Taixi feng Guimin lu National Engineering Research Center for Integrated Utilization of Salt Lake Resource East China University of Science and TechnologyShanghai 200237China Joint International Laboratory for Potassium and Lithium Strategic Resources East China University of Science and TechnologyShanghai 200237China

The local structure and thermophysical behavior of Mg-La liquid alloys were in-depth understood using deep potential molecular dynamic(DPMD) simulation driven via machine learning to promote the development of Mg-La alloys. The robustness of the trained deep potential(DP) model was thoroughly evaluated through several aspects, including root-mean-square errors(RMSEs), energy and force data, and structural information comparison results;the results indicate the carefully trained DP model is reliable. The component and temperature dependence of the local structure in the Mg-La liquid alloy was analyzed. The effect of Mg content in the system on the first coordination shell of the atomic pairs is the same as that of temperature. The pre-peak demonstrated in the structure factor indicates the presence of a medium-range ordered structure in the Mg-La liquid alloy, which is particularly pronounced in the 80at% Mg system and disappears at elevated temperatures. The density, self-diffusion coefficient, and shear viscosity for the Mg-La liquid alloy were predicted via DPMD simulation, the evolution patterns with Mg content and temperature were subsequently discussed, and a database was established accordingly. Finally, the mixing enthalpy and elemental activity of the Mg-La liquid alloy at 1200 K were reliably evaluated,which provides new guidance for related studies.

关键词： magnesium-lanthanum liquid alloys local structure macroscopic properties thermodynamic behavior deep potential mo-lecular dynamic simulation

Disruption of estrogen receptor beta in mice brain results in pathological alterations resembling Alzheimer disease

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Acta Pharmacologica Sinica 2004年第4期25卷 54-59页

作者： Qing-hong ZHANG2, Yan-hong HUANG3, yu-zhen HU, Geng-ze WEI,Xue-feng HAN, Shun-yan lu, yu-feng ZHAO 2Department of Physiology, Institute of Basic Medical Science, Departmentof Gynaecology and obstetrics, 3 Xijing Hospital, The Fourth Military Medicaluniversity, Xi-an 710032, Shaanxi, China Department of Physiology Institute of Basic Medical Science Xijing Hospital The Fourth Military Medical University 陕西 Xi'an 710032 Department of Gynaecology and obstertrics Xijing Hospital The Fourth Military Medical University 陕西 Xi'an 710032

AIM: To study the pathological characteristics of the mice with estrogen receptor β (ERβ) disruption in brain. METHODS: Immunohistochemistry method was applied in the study. RESULTS: β-Amyloid peptide(Aβ42) and apolipoprotein E (ApoE) immunoreactive substances were accumulated notably in cortex and limbic structures such as the hippocampus and amygdala in brain, resembling the pathological changes of human Alzheimer disease (AD). Aβ formed cloudy-like deposits in parenchyma of brain, while apoE also deposited along or surrounding the blood vessels. CONCluSIONS: ERβ is crucial to the development of neural degenerative disease, so modulation of Aβ metabolism via ERβ signal pathway might be beneficial for AD prevention or therapy.

关键词： beta-amyloid peptide apolipoprotein E estrogen receptor beta Alzheimer disease

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时变系统的模型匹配与跟踪问题

控制理论与应用 2014年第3期31卷 302-308页

作者：刘浏卢玉峰大连理工大学数学科学学院辽宁大连116024 连理工大学控制科学与工程学院辽宁大连116024

仿照时不变系统的次优模型匹配解的存在性证明方法,可以得到J–谱分解条件下时变系统的Nehari型模型匹配问题的次优解存在性.如何针对双边模型匹配的次优问题证明解的存在性还没有有效的方法.本文在套代数框架下研究了时变线性系统的次... 详细信息

仿照时不变系统的次优模型匹配解的存在性证明方法,可以得到J–谱分解条件下时变系统的Nehari型模型匹配问题的次优解存在性.如何针对双边模型匹配的次优问题证明解的存在性还没有有效的方法.本文在套代数框架下研究了时变线性系统的次优模型匹配和跟踪问题.首先,应用Douglas值域定理证明了耦合J–谱分解条件下次优模型匹配解的存在性,然后指出应用双参数控制器同时镇定n个系统,并且要求跟踪指标小于r的次优跟踪问题等价于同时强r镇定n-1个相关四块问题,最后给出了次优解的参数化.

关键词：次优控制模型匹配 J-谱分解同时镇定时变系统

On Stabilization for Linear Time-Varying Systems

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Journal of Mathematical Research and Exposition 2009年第5期29卷 761-773页

作者： lu yu feng Sill Cheng Kai School of Mathematical Sciences Dalian University of Technology Liaoning 116024 China

This paper deals with the stabilization problem for linear time-varying systems within the framework of nest algebras. We give a necessary and sufficient condition for a class of plants to be stabilizable, and we also... 详细信息

关键词： nest algebra causal linear system coprime factorization stabilization.