对时间自动机进行空性检测的过程和改进

为了提高对时间自动机进行空性检测的效率,研究了使用基于时钟区域(zone)的符号化方法和抽象对时间自动机进行空性检测,提出了针对时间自动机自身特点对检测过程进行改进的方法.通过使用基于zone的符号化表示方法和抽象,一个符号化状态表示显式的状态的集合,时间自动机的状态空间会显著缩小,不同的抽象方法对状态空间有不同的效果.符号化状态间不仅有相等关系还有包含关系,通过判断这种包含关系可以尽早的找到接收路径和避免不必要的状态展开从而提高空性检测的效率.实现了改进的检测过程,对一些例子进行了数据比较,取得了较好的实验结果.     

基于Flash 8的移动遮罩特效动画制作

本文利用Flash 8.0的遮罩特效制作了一个探照灯动画,在制作过程中,先创建一个文本图层,然后建立动画,最后建立背景并且修改完成。文重点介绍遮罩特效的原理、如何使用遮罩层、创作一个简单遮罩层,可扩展应用为各种制作镂空图形效果动画。     

高职高专校园网平台建设三大策略探讨

本文针对高职高专校园网平台建设中存在的问题,从技术、服务和管理策略方面进行思考,并对高职高专校园网平台建设提出相应的意见和建议.     

CORDIC based fast algorithm for power-of-two point DCT and its efficient VLSI implementation

—In this paper, we present a coordinate rotation digital computer (CORDIC) based fast algorithm for power-of-two point DCT, and develop its corresponding efficient VLSI implementation. The proposed algorithm has some distinguish advantages, such as regular Cooley-Tukey FFT-like data flow, identical post-scaling factor, and arithmetic-sequence rotation angles. By using the trigonometric formula, the number of the CORDIC types is reduced dramatically. This leads to an efficient method for overcoming the problem that lack synchronization among the various rotation angles CORDICs. By fully reusing the uniform processing cell (PE), for 8-point DCT, only four carry save adders (CSAs)-based PEs with two different types are required. Compared with other known architectures, the proposed 8-point DCT architecture has higher modularity, lower hardware complexity, higher throughput and better synchronization.     

Volume CAD—CW-complexes based approach

In this paper, we propose a novel shape and physical attribute handling system Volume-CAD designated for practical and robust use in the manufacturing process of various industries. The internal data structure ‘Kitta Cube’ is formalized by CW-complexes. Complex is a structure consisting of different dimensional items with consistency (without gap or overlaps), therefore allowing each volume comprising of a material separated by boundaries to be represented completely. Volume-CAD (VCAD¹) could be called ‘solid and fluid model’, as it goes beyond the solid model. As applications of VCAD, this paper discusses surface simplification of Kitta Cubes, cell labeling (three-dimensional coloring), and multiple-materials situation. These models can be used not only for manufacturing but also throughout the product life cycle from shipment tracking until the end of the product life cycle.     

Leakage current characterization for estimating the conditions of non-ceramic insulators’ surfaces

In this work both detection of the beginning of dry-band arcing and correlating the average value of leakage current (LC) with non-ceramic insulator surface damage have been investigated. Silicone rubber insulators were tested in salt-fog under different voltage and conductivity levels. The autocorrelation function (ACF) was calculated for both the fundamental and third harmonic components of LC during the early aging period (EAP). It has been observed that distinct differences exist in the behavior of both the fundamental and that of the third harmonic components of the LC during EAP. Although the fundamental component of the LC begins to grow immediately after starting the test, the third harmonic requires a much longer period of time to begin. Dry-band arcing is highly correlated with distortion in the LC and hence to its third harmonic component. But it has been observed that the level of the fundamental component of LC at which the third harmonic component started to increase is different from one case to another. As such, it is more appropriate to use the ACF of the third harmonic component of LC as an indication of dry-band arcing rather than a simple threshold value. Moreover, the average value of LC during late aging period (LAP) was correlated with the damage of non-ceramic insulators. It has been found that the average level of both the fundamental and third harmonic component of LC is well correlated with the different degrees of damage of non-ceramic insulators’ surface.     

Spanning trees set synthesis algorithm for custom VLSI global routing

In this paper, we study the problem of multi-terminal nets layout optimization. To solve the problem, we propose a polynomial-time algorithm, which first constructs minimum spanning tree and then generates spanning tree set. An algorithm for near-minimum spanning trees set with controllable length deviation from a minimum is proposed. Effective trees length deviation value and trees number are investigated.     

高速列车转向架轴箱轴承的热分析建模与仿真

以CRH2动车组的动力转向架的轴箱轴承(密封双列圆锥滚子轴承)为研究对象,利用温度场和热应力场的耦合关系,对该轴承建立了温度场和热应力分布的数值模型,再通过Matlab软件对建立的模型进行仿真分析和验证。结果表明:所采用的分析方法是合理、可行的,为后续的高速机车转向架传动装置中轴承的设计时的动态分析提供了一定的指导作用。