从测角后交最佳点位规律看规范规定之不足

本文分析了文献[1]所总结的测角后交两类公式在取得最佳点位时的规律,指出当前规范对此问题规定之不足.     

混沌量化算法研究及测试分析

对在信息安全应用中的各种混沌伪随机序列的产生方法进行了研究,对各种典型的一维混沌量化算法的性能进行了随机性测试分析和比较.试验结果显示,被大量采用的二值量化算法以及多次粗粒化算法均存在一些安全缺陷,因此提出了若干改进混沌量化算法,为混沌在信息安全中的应用提供了指导.     

基于FPGA+DDS的信号源设计与实现

采用DDS+FPGA+DAC数字信号激励器硬件电路和数字波形合成软件算法设计实现了宽带信号源所需要的各类信号,覆盖30 MHz～1 GHz频段,功率达到20 W.在完成了具体的设计和实验后实现了样机的制作,通过现场测试验证了其完全满足应用需求.     

可靠性技术在星载计算机设计中的应用

结合星载计算机的开发,从FMECA、抗辐照设计、ESD防护、结构力学设计与分析、热设计与分析、可靠性预计等方面阐述了星载计算机设计过程中的可靠性设计与分析方法。     

54Mb/s NRZ时钟数据恢复电路的设计与实现

提出一种采用双环路的时钟数据恢复电路,电路采用改进型Hogge鉴相器;鉴相环电荷泵充放电电流为13.06μA,改善了输出时钟的抖动影响;压控振荡器采用四级环型振荡结构,由伪差分结构延迟单元组成,降低了系统电路设计难度,减小了VCO的增益。通过Cadence软件的Spectre工具仿真,能够顺利地从54Mb/s的非归零码数据中提取出54MHz的同步时钟,时钟占空比为50%,满足设计要求。     

TSV constraints related to temperature excursion, pressure during molding, materials used and handling loads

The current paper focuses on several mechanical aspects of a waferlevel packaging approach using a direct face-to-face Chip-to-Wafer (C2W) bonding of a MEMS device on an ASIC substrate wafer. Requirements of minimized inherent stress from packaging and good decoupling from forces applied in manufacturing and application are discussed with particular attention to the presence of through-silicon vias (TSV) in the substrate wafer. The paper deals with FEM analysis of temperature excursion, pressure during molding, materials used and handling load influence on mechanical stress within the TSV system and on wafer level, which can be large enough to disintegrate the system.     

基于维修时间约束的机群系统可用度的仿真算法

在描述机群系统运行状态的基础上,通过对各结点间结构功能关系的量化处理,给出了描述机群系统中各结点随机变量的概率分布及其抽样方法;然后,依据对故障发生状态和修复状态的识别,确定出各结点的工作状态,从而建立了可用性仿真逻辑关系,得到了机群系统可用度的估计值,为机群系统可用性分析与设计提供了定量依据。     

代码组件的组合重用是一种新的程序设计范型

本文在描述了程序设计范型的特性之后,详细地介绍了代码组件的组合重用方法,提出并论述了代码组件的组合重用是一种新程序设计范型的观点.本文还详细地描述了这种新程序设计范型的特点,同时也指出了应当解决的一些课题.     

Modeling NOx emissions from coal-fired utility boilers using support vector regression with ant colony optimization

Modeling NO_x emissions from coal fired utility boiler is critical to develop a predictive emissions monitoring system (PEMS) and to implement combustion optimization software package for low NO_x combustion. This paper presents an efficient NO_x emissions model based on support vector regression (SVR), and compares its performance with traditional modeling techniques, i.e., back propagation (BPNN) and generalized regression (GRNN) neural networks. A large number of NO_x emissions data from an actual power plant, was employed to train and validate the SVR model as well as two neural networks models. Moreover, an ant colony optimization (ACO) based technique was proposed to select the generalization parameter C and Gaussian kernel parameter γ. The focus is on the predictive accuracy and time response characteristics of the SVR model. Results show that ACO optimization algorithm can automatically obtain the optimal parameters, C and γ, of the SVR model with very high predictive accuracy. The predicted NO_x emissions from the SVR model, by comparing with the BPNN model, were in good agreement with those measured, and were comparable to those estimated from the GRNN model. Time response of establishing the optimum SVR model was in scale of minutes, which is suitable for on-line and real-time modeling NO_x emissions from coal-fired utility boilers.     

基于AHM方法的土壤侵蚀影响因子控制方案评价

在基于层次分析法(Analytic H ierarchy Process,简称AHP)的土壤侵蚀影响因子控制方案选择的基础上,首次利用层次分析模型(Analytic H ierarchicalModel,简称AHM)方法对影响土壤侵蚀的因子进行了定量分析。结果表明,应以现代加速侵蚀指标方案来控制土壤侵蚀,从而达到有效控制土壤侵蚀、发展生产、能动地改造自然的目的。为工程决策提供了有力的支撑,有利于促进土壤侵蚀和水土保持的可持续发展。