Well-posed analysis for a class of Helmholtz equation with periodic coefficients

The scattering theory in periodic structures has many applications in modern mierooptics and industry. Periodic structures are often referred to as diffraction gratings. In this paper we consider a planar dielectriclayer modulated grating problem. The diffraction problem may be modeled by a Helmholtz equation with periodic coefficients. Results on existence and uniqueness of the solution for the diffraction problem are obtained by variational method and integral equation method, respectively. At the end of the paper, we also discuss the Born approximation to the solution of an equivalent inlegral equation.     

The comparison and analysis of real estate operation in China

This paper raises the comparison method of operational stages of the real estate market. In order to select similar operational stages, we established an analysis model by applying fuzzy grade-of-memhership clustering in this paper. Firstly, we select the materials information of the real estate market, in America, Germany and Japan. Seeondly, the real estate markets of America, Germanv and Japan are divided into several different stages. Lastly. we apply the method of fuzzy grade-of-membership clustering to select comparable stages. The result of analysis indicates that the real estate market of Japan and Germany (1960-1980) are similar to the market in China.     

关于矩阵乘积的一些L~2范数意义下的Cauchy型不等式(英文)

In many important partial differential equations, matrices are involved. In order to study these equations, we need the estimations of the matrices in L~2 norm. In this paper, we give some estimations of some matrices in some certain "inner" product and "ector" product. Some inequalities similar to Cauchy inequality are given.     

A STUDY OF THE YELLOWING MECHANISM OF CLEAR GRP

The yellowing of clear GRP in outdoor applications resalts primarily from photo-oxidation ageing of clear UP (unsaturated polyester) resins. In this paper, the chemical changes in the molocular structures of clear UP resins dtring photo-oxidation ageing are studied by FTIR spectra, and some of the essential reactions in the processes are. discassed. Since the re(?)o(?) betweea "yellowing" and ageing processes is determined, We have a theoretical basis on which we can effectively swarch for methods of anti-weathering for clear UP resins.     

Low power all optical switches

In this paper, we propose a new design of all fiber optical switches by using a high finesse ring resonator (RR) side coupled Mach-Zehnder interferometer. We will show that by compensating the total loss in the RR the switching power can be decreased greatly and by loss, compensating the bistability effect in RR can be cancelled and the switching performance can be improved. In addition, we will show that by using Erbium doped fiber for fabricating the RR we can obtain switching power threshold in mW range.     

Average sampling theorems for shift invariant subspaces

The sampling theorem is one of the most powerful results in signal analysis. In this paper, we study the average sampling on shift invariant subspaces, e.g. wavelet subspaces. We show that if a subspace satisfies certain conditions, then every function in the subspace is uniquely determined and can be reconstructed by its local averages near certain sampling points. Examples are given.     

Thermal model for discrete vegetation and its solution on pixel scale using computer graphics

In this paper, we discuss how the multi-reflection of thermal emission affects the calculation of radiation balance. With the help of computer graphics, the four components of discrete vegetation are analyzed in detail and the curves of BRDF for the discrete vegetation can be obtained as well. A new model is put forward to inverse the temperatures of four components. The solution obtained by using computer graphics is consistent with observations in the field experiment in Yucheng Remote Sensing Comprehensive Site of CAS. Furthermore, the method can be used to retrieve land surface temperature based on multi-angle thermal infrared remotely sensed data.     

Imitation of Fabric Flagging in the Wind with 1/F~β Noise

This paper presents a dynamic simulation model,based on noise,to simulate fabric flagging in the wind.The wind noise is generated by two sine functions defined in advance.The frequencies and amplitudes of these sine functions are change- able to presenting the basic model of the fabric.In order to obtain more fabric fluctuant effect,we adopt a cosine function to achieve the fabric dynamic display effect.In the actual process,the traditional Phong illumination model is improved.Therefore, the model of simulating fabric flagging in the wind can be built successfully.Comparison with the physical model shows that it is a fast arithmetic because of adopting a new model in stead of the time consuming iteration arithmetic.It can achieve a friendly de- sign interface and an ideal simulation effect.Designers can select wind force and fabric material by controlling different parame- ters.The basic characteristics of fabric swaying in the wind are simulated efficiently and displayed vividly.     

STUDY ON UTILIZATION OF COAL-SERIES KAOLIN ROCK RESOURCES

In this paper,the main factors that influence on qualitiesof kaolin in the area are revealed by studying the properties of coal-scrieskaolin in Enshi,Hubei(P.R.China),technologies of ferrum and carbonelimination for coal-series kaolin are investigated,and ways to fully uti-lize the resource are hopeful to be sought.     

Primary Exploration of Reliability Evaluation of Computer Live Forensics Model on Physical Memory Analysis

The integrity and fidelity of digital evidence are very important in live forensics. Previous studies have focused the uncertainty of live forensics based on different memory snapshots. However, this kind of method is not effective in practice. In fact, memory images are usually acquired by using forensics tools instead of using snapshots. Therefore, the integrity and fidelity of live evidence should be evaluated during the acquisition process. In this paper, we study the problem in a novel viewpoint. Firstly, several definitions about memory acquisition measure error are introduced to describe the trusty. Then, we analyze the experimental error and propose some suggestions on how to reduce it. A novel method is also developed to calculate the system error in detail. The results of a case study on Windows 7 and VMware virtual machine show that the experimental error has good accuracy and precision, which demonstrate the efficacy of the proposed reducing methods. The system error is also evaluated, that is, it accounts for the whole error from 30％ to 50％.     

线性矩阵不等式及在控制理论中的应用

系统和控制理论中许多重要的问题，都可转化为线性矩阵不等式约束的凸优化问题，从而使其在数值上易于求解。本文阐述了线性矩阵不等式方法的基本概念和内容，并介绍了有关算法及计算软件，最后列举二个例子说明其在控制理论中的应用。     

线性矩阵不等式及其在随机控制中的应用

随机控制理论中许多重要的问题，都可转化为线性矩阵不等式（LMI）约束的凸优化问题，从而使其在数值上易于求解。本文阐述了线性矩阵不等式方法的基本概念和内容，并介绍了有关算法及计算软件，最后举例说明其在随机不确定系统的鲁棒控制中的应用。     

时滞离散切换系统基于观测器的输出反馈镇定

针对一类任意切换律下含有时滞的不确定离散切换系统,研究了其基于观测器的输出反馈鲁棒镇定问题.所考虑的系统不确定性是时变的,且满足范数有界条件.假定下一时刻要切换到的子系统可预先获得,给出了该含有时滞的离散切换系统状态观测器形式,通过构造增广系统,设计基于状态观测器的无记忆反馈控制器,以保证相应的增广闭环系统鲁棒渐近稳定.借助于Lyapunov函数方法和线性矩阵不等式技术,给出了不确定切换系统存在状态观测器和基于观测器的鲁棒控制器的充分条件,并将该充分条件转化为一组线性矩阵不等式的可行性问题,同时给出相应的状态观测器和基于观测器的鲁棒控制器.最后通过一个数值算例验证了本文结果的有效性.     

带有非线性扰动的时滞系统的鲁棒控制

本文针对具有非线性扰动的时滞系统,通过构造Lyapunov泛函,利用Lyapunov方法,推导出系统时滞依赖鲁棒稳定性判据。且将结果表示成线性矩阵不等式(LMI)的形式,并进一步给出此类控制系统状态反馈控制器的设计方法.最后给出算例,说明了该方法的有效性.     

一类非线性中立型系统的状态反馈时滞相关Ｈ ｉｎｆｉｎｉｔｙ控制

研究了一类非线性中立型时滞系统的H-infinity控制问题.利用了适当的参数待定的Lyapunov-Krasovskii泛函及LMI方法获得了中立型系统的稳定性时滞相关的判据,给出了H-infinity状态反馈控制器存在的时滞依赖的充分条件.所采用的方法在设计、求解控制器时不需要做矩阵变换,求解简单,利用Matlab的LMI工具箱求解方便,并且给出的数值仿真实例说明了方法的有效性.     

广义T-S模糊系统的鲁棒非脆弱控制

在控制器的实现过程中,由于A/D、D/A转换,有限字长限制以及舍入误差等因素的影响,使得控制器自身具有不确定性.非脆弱控制的目的就是使控制器能够克服这种不确定性,保证系统的稳定性,并满足性能指标要求.研究了广义T-S模糊系统的鲁棒非脆弱控制,考虑控制器增益为加法式摄动,基于李亚普诺夫稳定性定理和线性矩阵不等式(LM I)方法,给出了非脆弱鲁棒控制器的存在条件与求解方法.仿真实例表明了该方法的有效性和可行性.     

离散模糊时滞系统的多目标控制

基于离散时滞Takagi-Sugeno（T-S）模糊模型的多目标控制问题.设计了一个不仅满足稳定性要求,而且同时满足H2和H∞性能指标的模糊控制器.由线性矩阵不等式方法（LMI）给出了一类离散时滞模糊系统并满足该性能指标的控制器存在的充分条件,期望控制器可通过求解给定的LMI而获得.     

一类时滞T—S模糊广义系统的无源控制

目的设计使一类时滞T—S模糊广义系统的严格无源控制的控制器．得到使闲环系统容许、严格无源的充分条件,并将此条件用线性矩阵不等式（LMI）表示．方法通过求解线性矩阵不等式,得到所设计的控制器．结果获得了使系统容许、严格无源的状态反馈控制器设计方法．结论通过所设计的控制器能够使时滞T—S模糊广义系统容许、严格无源,所给算例说明该方法简单、可行．     

多重时滞离散非线性系统的鲁棒预测控制

为解决一类同时存在多重状态时滞、输入时滞和非线性扰动的不确定离散非线性系统的控制问题,提出一种具有状态反馈控制结构的鲁棒模型预测控制器设计方法.首先,充分利用时滞的上下界信息构造一个改进的二次Lyapunov-Krasovskii泛函;其次,利用线性矩阵不等式(LMI)方法将min-max最优化求解困难的问题转化成具有LMI约束的凸优化问题,并给出鲁棒预测控制器存在的充分条件及其表达式.理论证明该方法设计的控制器保证闭环系统鲁棒渐进稳定.仿真算例验证了所提出方法的有效性.     

基于观测器的线性中立时滞系统控制

针对确定性中立时滞系统,利用Lyapunov函数法研究了该系统基于观测器的控制问题。结合线性矩阵不等式(LM I)方法,给出了该系统基于观测器渐近稳定的充分条件及观测器控制律的设计方法。最后的仿真例子说明了所给方法的有效性和可行性。