一类非线性不确定时滞系统的记忆与无记忆复合H∞状态反馈控制

针对一类具有状态非线性不确定性的线性时滞系统,基于Lyapunov稳定性理论,利用线性矩阵不等式（LMI）方法,讨论了该类时滞系统的记忆与无记忆复合H∞状态反馈控制器的设计问题。在非线性不确定性满足增益有界条件下,得到了该类时滞系统的满足鲁棒H∞性能的一个充分条件。通过求解一个线性矩阵不等式-LMI,即可获得鲁棒H∞控制器。     

一类非线性不确定时滞系统鲁棒容错控制

研究一类不确定非线性时滞系统的鲁棒容错控制问题.针对不确定非线性时滞系统,基于执行器连续型增益故障模式,利用Lyapunov-Krasovskii泛函方法和线性矩阵不等式方法,推导了当一类非线性不确定系统满足一定范数有界条件时,闭环系统时滞无关鲁棒容错控制器存在的充分条件,并给出了状态反馈鲁棒容错控制器的设计方法.将所设计的状态反馈控制方法应用于某一非线性不确定时滞系统,仿真结果表明设计的控制器不仅使得该故障系统对于执行器故障具有完整性,并且能达到给定的H∞性能指标,从而验证了所提出方法的可行性和有效性.     

具有避碰和保持连通的多智能体鲁棒编队控制

针对多智能体系统在形成编队的过程中存在相互碰撞、通信中断和外部干扰的问题,考虑了具有避碰和保持系统连通的二阶非线性多智能体鲁棒编队控制问题。基于人工势场法设计了具有保持系统连通的多智能体避碰算法,并利用分布式控制法和共识理论设计了多智能体鲁棒编队控制律,从而使得多智能体系统准确地实现编队,避免碰撞和保持系统连通。利用李雅普诺夫稳定性理论和线性矩阵不等式证明了系统的稳定性和跟踪误差的收敛性。通过数值仿真实例验证了所提编队控制律的有效性。     

具有时滞和的非线性系统的鲁棒稳定性分析

针对具有时滞和及模有界参数不确定性的非线性系统,研究了鲁棒稳定性问题。通过构造新的Lyapunov泛函。其中考虑了时变时滞和时滞上界信息,并应用新的方法估计Lyapunov泛函导数的上界,以线性矩阵不等式形式给出了系统的时滞相关型稳定性判据。数值实例表明了结果的有效性和较小保守性。     

中立型BAM神经网络的鲁棒稳定性分析

本文主要研究不确定中立型BAM神经网络的鲁棒渐近稳定性问题, 不确定参数具有较范数有界更一般的线性分式形式, 考虑了中立时滞与状态时滞不相等的情况, 激励函数只要求满足有界和全局李普希兹条件,通过构造一个新的Lyapunov泛函, 利用Lyapunov-Krasovskii稳定性理论和一些不等式技术, 得到了具有较小约束的时滞中立型BAM神经网络的鲁棒渐近稳定性条件, 这个充分条件以线性矩阵不等式的形式给出, 容易验证.最后, 通过数值实例验证了所提算法的正确性和保守性.     

一类非线性时滞系统的鲁棒H∞滤波器设计

 研究了满足下列条件的时滞系统的鲁棒H_∞滤波问题:假设系统的参数矩阵带有不确定性,且不确定参数是时变且范数有界的.在系统的状态与输出中同时都含有非线性无穷分布时滞与离散时滞.在设计滤波器的过程中,引入了一个新的Lyapunov-Krasovskii泛函.通过线性矩阵不等式技术,提出了参数不确定时滞系统的鲁棒H_∞滤波器存在的时滞依赖条件.鲁棒H_∞滤波器可以保证带有参数不确定性的滤波误差系统是渐近稳定的,并且满足给定的H_∞性能指标.通过仿真的研究证明了该方法的有效性.     

时滞依赖型区间时滞系统非脆弱H_∞控制

针对一类状态和控制输入矩阵均为区间矩阵的不确定时滞系统,其中状态和控制输入同时具有未知但有上界的时间滞后,基于Lyapunov稳定性理论,利用线性矩阵不等式(LMI)方法,讨论了该类时滞系统的时滞依赖型非脆弱H∞状态反馈控制器设计问题.在区间不确定性和控制器执行机构扰动均满足增益有界条件下,得到了该类时滞系统的满足H∞性能的一个充分条件.通过求解一个线性矩阵不等式(LMIs)组,即可获得鲁棒H∞控制器.最后对某型飞机作机动飞行仿真,仿真结果表明该鲁棒控制器设计方法是有效的.     

参数不确定的单时滞系统基于简化的L-K泛函的稳定性分析

参数不确定和时滞广泛存在于各种实际的控制系统中,而且它们往往是导致系统不稳定或性能下降的原因。本文基于Lyapunov稳定性理论,通过构造简化的Lyapunov-Krasovskii泛函,同时应用线性矩阵不等式(LMI:linearmatrix inequality)方法,研究了参数不确定和单时变时滞系统的鲁棒稳定性问题,并导出了由LMI表示的该类系统的鲁棒稳定性判据,而且,通过这类简化的L-K泛函,在充分利用时滞信息的基础上减少了判据的保守性。最后借助含不确定性扰动的具有单时变时滞的单机-无穷大系统模型,分析了保持鲁棒稳定时系统可承受的最大时滞的界限,数值仿真验证了方法的有效性。     

二阶时变时滞多智能体系统快速一致性算法

针对多智能体系统的动态性能问题,本文对带有时变时滞的二阶多智能体系统快速收敛速度进行分析,提出快速收敛一致性算法.考虑智能体网络为无向拓扑图,时滞是具有上界且任意变化的.基于频域角度分析多智能体一致性,利用图论和矩阵论,将多智能体网络系统一致性转换为线性系统理论控制问题,结合小增益理论方法,分析系统的稳定性和连通性,并得到了系统快速收敛一致性的充分条件.最后通过MATLAB数值仿真实例,验证了本文算法的有效性.     

受限切换拓扑时延多智能体系统的指数一致性

针对多智能体系统的一致性问题,建立一阶动力学模型,并考虑时变时延和受限拓扑切换,设计出相应的一致性控制器,其中有向网络拓扑根据ADT型切换信号进行切换,并通过状态变换将一致性问题转化为低阶差异系统的指数稳定性问题,通过构造分段Lyapunov-Krasovskii泛函,并借助詹森不等式给出在线性矩阵不等式框架下多智能体系统达到指数一致性的充分条件。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

A method for calculating the center position of collimated light

It is a key problem to accurately calculate beam spots＇ center of measuring the warp by using a collimated laser. A new method, named double geometrical center method （DGCM）, is put forward for the first time. In this method, a plane wave perpendicularly irradiates an aperture stop, and a charge couple device （CCD） is employed to receive the diffraction-beam spots, then the geometrical centers of the fast and the second diffraction-beam spots are calculated respectively, and their mean value is regarded as the center of datum beam. In face of such adverse instances as laser intension distributing defectively, part of the image being saturated, this method can still work well. What＇s more, this method can detect whether an unacceptable error exits in the courses of image receiving, processing and calculating. The experimental results indicate the precision of this method is high.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.