多指标约束下的容错控制系统设计

对一类线性不确定系统,研究了区域极点指标、H∞指标和方差指标约束下的容错控制器的设计问题.在更一般、更实际的执行器故障模型下,利用线性矩阵不等式方法,建立了容错控制中三类指标的相容性理论.分析了与区域极点指标相容的H∞指标和方差指标的取值范围,并在相容指标约束下给出了有效的控制器设计方法.仿真实例验证了结果的有效性.     

区域极点和H∞指标约束下的满意容错控制方法

对一类不确定性不满足匹配条件的线性系统,研究了区域极点和H∞指标约束下的满意容错控制器的设计问题.在连续型执行器故障的模式下,利用线性矩阵不等式技术,给出了2个指标约束下容错性能的相容性判别条件,分析了与区域极点指标相容的H∞指标的取值范围,并在相容指标约束下给出了满意容错控制器的设计方法.对歼击机纵向通道控制系统的仿真结果表明,所设计方法是有效的.     

相容指标约束下的线性时滞广义系统容错控制设计

对一类线性不确定时滞广义系统,讨论了H∞指标和区域极点指标相容条件下的容错控制器的设计问题。在更一般、更实际的执行器故障模型下,利用线性矩阵不等式方法,建立了容错控制中两类指标的相容性理论。分析了与H∞指标相容的区域极点指标的取值范围,并在相容指标约束下给出了有效的控制器设计方法。仿真结果表明,该方法是有效的,且更能保证系统的动态性能。     

区域极点和H∞指标约束下的满意容错控制方法

对一类不确定性不满足匹配条件的线性系统，研究了区域极点和H∞指标约束下的满意容错控制器的设计问题，在连续型执行器故障的模式下，利用线性矩阵不等式技术，给出了2个指标约束下容错性能的相容性判别条件，分析了与区域极点指标相容的H∞指标的取值范围，并在相容指标约束下给出了满意容错控制器的设计方法，对歼击机纵向通道控制系统的仿真结果表明，所设计方法是有效的。     

非线性系统H_∞模糊输出反馈容错控制

研究了一类含有执行器故障的非线性系统的H∞模糊输出反馈容错控制问题.采用T-S模糊模型对非线性系统进行建模,用模糊观测器重构系统状态.针对设计过程中的双线性矩阵不等式问题,采用相似变换法将其转化为线性矩阵不等式(LMI)问题.利用Lyapunov稳定性理论和线性矩阵不等式方法,给出了H∞模糊输出反馈容错控制器存在的充分条件.通过求解由一组LMI所表示的凸优化问题可以得到次优H∞模糊反馈容错控制器.所设计的控制器可保证系统在故障时满足给定H∞性能约束下,使正常情况下的H∞性能最优.最后通过对小车倒立摆系统的仿真验证了该设计方法的有效性.     

相容指标约束下离散不确定系统的满意容错控制

针对一类线性离散不确定系统,研究了当执行器发生故障时,扇形区域极点指标、H∞指标和方差指标约束下的满意容错控制问题。在更一般、更实际的执行器故障模型下,利用线性矩阵不等式方法,建立了容错控制中三类指标的相容性理论,并在相容指标约束下给出了有效的控制器设计方法。数值算例验证了结果的有效性。     

基于约束软化的满意容错控制-输出反馈情形

现有的满意容错控制成果难以处理非凸非线性约束,无法用于在线重构容错控制器设计,针对一类离散系统的传感器故障,研究容错系统具有上述特性的闭环区域极点指标、二次型保性能指标和控制输入等约束的满意容错控制问题.借鉴预测控制对多种约束的软化处理策略,利用被控输出反馈控制结构和在线非线性优化技术,给出一种根据故障估计信息进行递推控制的主动满意容错控制器的数值化设计算法,并分析闭环容错系统的稳定性.据此设计的满意容错控制器可使闭环容错系统在保证稳定性和控制输入约束条件下具有满意的优化性能.仿真算例验证文中设计算法的有效性.     

相容性指标下的鲁棒H∞容错控制器设计

该文基于线性矩阵不等式(LMI)，研究时变不确定系统在线性分式变换模型下的鲁棒H∞容错控制问题。通过引入H∞性能指标，考虑系统的被控输出对外干扰信号的抑制能力。利用LMI方法，分析了相容指标的取值范围，鲁棒H∞容错控制器存在的充分条件，并给出了控制器的构造性设计方法。     

多性能指标约束下动态输出反馈容错控制

针对一类具有范数有界不确定性的线性连续随机系统,研究了极点指标、H∞指标和方差指标约束下的动态输出反馈满意容错控制问题.在执行器连续增益故障模型下,分析了容错控制中3类期望指标的相容性,并给出了3类指标约束下具有最小能量的动态输出反馈满意容错控制器的设计方法.仿真算例验证了方法的有效性和对系统进行满意容错控制的必要性.     

一类非线性系统的模糊可靠控制器设计

基于T-S模糊模型,从正常闭环系统的可靠性问题入手,利用线性矩阵不等式(LMI)方法,研究一类非线性系统的模糊可靠H∞控制器设计问题.首先,对前期已有的结果进行了描述和比较,然后给出了T-S模糊系统的数学模型,并以线性矩阵不等式(LMI)的形式提出了系统模糊可靠H∞控制器存在的充分条件和控制器设计方法.所设计的模糊可靠H∞控制器的设计方法简明,使得故障闭环系统二次稳定,满足H∞性能指标,便于应用.数值例子验证了结论的正确性和控制器设计方法的有效性.     

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.     

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     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

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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