Quantized H∞ control for a class of 2-D systems with missing measurements

In this paper, the problem of quantized H∞ control is investigated for a class of 2-D systems described by Roesser model with missing measurements. The measurement missing of system state is described by a sequence of random variables obeying the Bernoulli distribution. Meanwhile, the state measurements are quantized by logarithmic quantizer before being communicated. By introducing a new 2-D Lyapunov-like function, a sufficient condition is derived to guarantee stochastically stable and H∞ performance of the closed-loop 2-D system, where the method of sector-bounded uncertainties is utilized to deal with quantization error. Based on the condition, the quantized H∞ control can be designed by using linear matrix inequality technique. A simulation example is also given to illustrate the proposed method.

     

使用系数矩阵变换极性转换的MPRM电路面积优化

为缩短布尔函数系统混合极性Reed-Muller(mixed-polarity Reed-Muller,MPRM)电路面积优化过程的时间,提出了能在任意极性值的MPRM间进行极性转换的系数矩阵变换方法.使用系数矩阵表示布尔函数系统,通过对系数矩阵进行分隔,使用置换和折叠操作完成MPRM极性转换以加快极性转换速度;在此基础上,给出了适用于较大规模MPRM电路的面积优化算法,其中使用遗传算法进行极性空间搜索,并采用基于最短个体距离的适应度计算方法进一步缩短优化过程中的极性转换时间.实验结果表明,与其他MPRM极性转换方法相比,文中方法能够提高MPRM电路面积优化的速度.     

小型飞行器综合测试系统方案设计

针对小型飞行器系统各部件在研制和生产中的测试要求,提出了小型飞行器综合测试系统的方案设计;方案设计中详细介绍了系统组成,并对方案中涉及的航空电子分系统、发动机分系统、无线电数据链分系统的测试内容及测试方法进行了分析说明;根据测试方法和测试内容,给出了综合测试系统的硬件设计原理和软件设计流程;运用该设计方案进行了综合测试设备发动机分系统测试的研制工作,并投入试运行,结果表明该方案设计合理可行,可推广应用于该领域或其它领域的测控系统的研制中。     

自变量选择及其并行算法

１．引 言 航天技术的发展带来了超大量的数据,如何从这些超大量的数据中获取所需的信息已成为航天技术发展迫切需要解决的关键技术之一．战略导弹的研制与定型和载人航天工程需要高精度的外测、遥测、光测测量数据．从多套、多站、多种测量设备的联合测量数据中摸清误差规律、调整参数到优选模型环节需要处理成百上千个线性和非线性模型,需要建立一个十分复杂和庞大的数据处理集成系统,其计算量是十分巨大的． 从已知的（多参数的）大型线性模型与非线性模型中,以提高数据处理的质量为依据,建立优选模型的准则,并提供有效的计算方法…     

A Piecewise Grey System Model for Study the Effects of Anthropogenic Activities on Karst Hydrological Processes

Sustainable groundwater development must rely on a good understanding of hydrological processes, especially under effects of anthropogenic activities. This paper develops a piecewise analysis based on grey system model for study effects of anthropogenic activities on hydrological processes. The time series of precipitation and spring discharge were segmented into three time periods depending on whether variations are due to climate variation: the predevelopment stage, the transition stage, and the new equilibrium stage. Then we modeled hydrological process of the predevelopment stage and new equilibrium stage by the grey system model. By comparing the model results, we can quantify the effects of human activities on hydrological processes. We applied the model to Liulin Springs China. The results indicated that the hydraulic response time of the spring discharge to precipitation from the predevelopment stage to the new equilibrium stage, ranges from less than 1 year to up to 4 years. The results revealed that human activities slow the groundwater flow. GM (1,N) models of Liulin Springs discharge showed that the driving coefficients of precipitation to the spring discharge decreased from 0.012272 in the predevelopment stage to 0.007753 in the new equilibrium stage, which means that groundwater recharge ability has reduced about 36.82 %. Human activities in Liulin Springs have drastically changed the groundwater system. Piecewise grey system model is a robust method for hydrological process simulation.     

基于FPGA的全局异步局部同步四相单轨握手协议实现

在常规FPGA中设计了基于LUT的异步状态保持单元,实现了全局异步局部同步系统的接口电路、时钟暂停电路,进一步完成四相单轨握手协议。基于Quartus软件的逻辑锁定技术,采用Verilog HDL进行行为描述,构建了无冒险C单元库。在Altera CycloneⅡEP2C35F672C6器件上,完成了GALS系统的时序仿真,证明了四相单轨握手的正确性。     

基于FPGA的PUSCH信道估计仿真与实现

基于最小平方(LS)算法,利用FPGA实现了一种适用于TD-LTE系统的上行信道估计算法。主要研究了如何利用FPGA实现LS算法,包括算法的介绍、方案的形成、FPGA实现的处理流程、FPGA实现结果及分析。以Virtex-5芯片为硬件平台,完成了仿真、综合、板级验证等工作。实现结果表明,该信道估计算法应用到TD-LTE系统具有良好的稳定性和可行性。     

DLL?技术在水文预报系统中的应用

在水文预报系统开发中,通过 DLL 技术的应用,既充分发挥多种开发语言各自的特长,提高系统开发效率,又可提高系统的运行速率,增强系统的可扩展性.详细分析用 VB 创建及测试水文预报模型.DLL 的步骤,以及在 ASP.Net 中如何调用 VB 创建的 DLL 进行水文预报.程序编写和调用实例证明,使用 DLL 技术实现水文预报的方法是切实有效的     

小波神经网络在图像配准中的应用

提出了一种基于小波网络的图像配准方法。将特征点定义进行了推广,提出了一种以特征区域定义和提取方法。使用Zernike矩表征区域的特征并进行特征区域的对应。因图像配准变换是复杂且难以预知的,利用小波神经网络具有良好的函数逼近性能,提出了具有局域特性的小波神经网络模型逼近图像的配准变换。实验表明这是一种有效的图像配准方法。