参数摄动系统的鲁棒极点配置

把不确定系统的鲁棒极点配置与LQR问题相结合,首先通过矩阵变换,将不确定系统的区域极点问题转换成鲁棒镇定问题,然后通过优化二次型性能指标,得到状态反馈控制器,并提出了相应的算法。仿真结果表明了此方法的有效性。     

多输入线性系统极点配置问题的算法研究

极点配置是通过一个状态反馈矩阵的选取,使闭环系统的极点配置在希望的位置,从而使系统具有较满意的性能。对于多输入线性系统,状态反馈矩阵K的解不唯一,目前常用的设计方法都没有解决K的优化设计问题。将遗传算法引入基于Sylvester方程的算法中,优化反馈矩阵,仿真结果表明,该算法求出的反馈矩阵K优于其他各种方法。     

线性系统极点正规配置问题

基于正规矩阵特征值对其元素变化的不敏感性,讨论线性系统极点的正规配置问题,即设计状态反馈控制律,将闭环控制系统极点配置到期望位置的同时使闭环状态矩阵为正规矩阵,从而达到增强控制系统的鲁棒性的目的.对于线性时不变系统,给出期望极点集可正规配置的充分必要条件及反馈控制律的一般表达式,并结合示例给出算法.     

广义系统具有完整性圆盘极点配置控制器设计

考虑线性连续广义系统具有完整性的圆盘极点配置设计问题·利用广义李亚普诺夫方程和不等式给出系统正则、无脉冲,以及极点在圆盘内的充分必要条件·同时针对执行器失效的线性连续广义系统,利用Riccati不等式给出具有执行器完整性圆盘极点配置控制器的设计方法,所设计的状态反馈控制器在系统正常时是正则、无脉冲、极点配置在圆盘内即系统是D允许的,在一定条件下,仍能使执行器故障具有D允许性     

基于Matlab多输入系统极点配置的研究

多输入系统极点配置问题的求解是一个繁琐的过程,采用Matlab语言编程可以方便地实现极点任意配置.本文分析了3种常用极点配置问题的算法,并针对这3种算法给出了一个具有实用价值的Matlab通用程序.通过实例进行比较,验证方法的正确性与有效性.     

基于圆形区域极点配置的降维状态观测器设计

设计观测器的目的是利用系统的输出量和输入量来重构状态。在设计观测器过程中，除了要求状态估计值ｘ渐近逼近真实值ｘ外，不希望两者间有一个合理的衰减率，而这与观测器系统的极点位置密切相关，精确配置极点的观测器难以满足其它期望性能指标约束，将观测器系统矩阵的极点配置于一指定区域内，可使极蹼的选取获得较大的自由度。该文对线性定常系统的降维状态观测器区域极点配置问题进行了研究，通过对观测器增益阵的分析设计，给     

不确定系统的区域极点配置

研究了不确定系统的鲁棒区域极点配置问题，利用本文提出的方法可以将不确定系统的闭环极点配置在左半复平面的某一扇形域，同时本文也给出了输出反馈和状态反馈控制器的解析表达式。     

响应率法求解二阶部分极点配置问题

给出一种求解多输入二阶控制系统的最小范数部分极点配置问题的新算法.该算法将部分极点配置问题转化为数值优化问题,使得在只有系统响应率的前提下,实现极点配置,同时保证得到的反馈矩阵的范数最小.数值实验的结果表明:该算法是可行性的.     

基于圆盘极点约束的系统不确定项容忍区间分析

在线性系统中基于Lyapunov稳定性理论,讨论了双不确定项同时波动时其容忍区间的算法,并结合闭环极点配置和线性矩阵不等完成圆盘极点配置问题中系统不确定项的冗余设计。数值仿真验证了本文控制器设计方法的可行性。     

离散随机系统的自适应极点配置

给出了离散随机系统的一种自适应极点配置算法，该算法不需要持续激励条件，就能保证自适应控制系统的全局稳定性．     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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