Matrix unit cell scheduler (MUCS) for input-buffered ATM switches

This paper presents a novel matrix unit cell scheduler (MUCS) for input-buffered asynchronous transfer mode (ATM) switches. The MUCS concept originates from a heuristic strategy that leads to an optimal solution for cell scheduling. Numerical analysis indicates that input-buffered ATM switches scheduled by MUCS can utilize nearly 100% of the available link bandwidth. A transistor-level MUCS circuit has been designed and verified using HSPICE. The circuit features a regular structure, minimal interconnects, and a low transistor count. HSPICE simulation indicates that using 2-μm CMOS technology, the MUCS circuit can operate at clock frequency of 100 MHz     

Statistical estimation of average power dissipation usingnonparametric techniques

In this paper, we present a new statistical technique for estimation of average power dissipation in digital circuits. The present parametric statistical technique estimates the average power based on the assumption that the power distribution can be characterized by a preassumed function. Large error can incur when the assumption is not met. On the other hand, the existing nonparametric technique, although accurate, is too conservative and requires a large sample size in order to achieve convergence. For a good tradeoff between simulation accuracy and computational efficiency, we propose a new nonparametric technique using the properties of the order statistics. It is generally applicable to any type of circuit irrespective of its power distribution function. Compared to the existing nonparametric technique, it is much more computationally efficient since it requires a much smaller sample size to achieve the same accuracy specification. This new technique is implemented in the distribution-independent power estimation tool (DIPE). DIPE is empirically demonstrated to be more robust and accurate than the parametric technique     

Interdiffusion behavior of Hg in HgTe/CdTe superlattices grown on Cd0.96Zn0.04 Te (211)B substrates by molecular beam epitaxy

Double-crystal x-ray rocking curve (DCRC) and secondary-ion mass-spectroscopy (SIMS) measurements have been performed to investigate the effect of rapid thermal annealing on the interdiffusion behavior of Hg in HgTe/CdTe superlattices grown on Cd_0.96Zn_0.04Te (211)B substrates by molecular beam epitaxy. The sharp satellite peaks of the DCRC measurements on a 100-period HgTe/CdTe (100Å/100Å) superlattice show a periodic arrangement of the superlattice with high-quality interfaces. The negative direction of the entropy change obtained from the diffusion coefficients as a function of the reciprocal of the temperature after RTA indicates that the Hg diffusion for the annealed HgTe/CdTe superlattice is caused by an interstitial mechanism. The Cd and the Hg concentration profiles near the annealed HgTe/CdTe superlattice interfaces, as measured by SIMS, show a nonlinear behavior for Hg, originating from the interstitial diffusion mechanism of the Hg composition. These results indicate that a nonlinear interdiffusion behavior is dominant for HgTe/CdTe superlattices annealed at 190°C and that the rectangular shape of HgTe/CdTe superlattices may change to a parabolic shape because of the intermixing of Hg and Cd due to the thermal treatment.     

Reliability and performance analysis of time – space – time switching networks with multiple separated space switches

Since electronic switching systems usually require very strict reliability requirements as well as good performance objectives, we need to jointly analyse the performance and reliability of switching systems. In this paper, we compare conventional time–space–time switches with single space switches with those with multiple separated space switches, from the viewpoints of reliability and performance. We consider time–space–time switching networks which consist of N incoming time switches, i.e. one NxN space switch, two (N/2)x(N/2) space switches, and four (N/4)x(N/4) space switches. We introduce a Markov reliability model to study the effect of failures and analyse the reliability and performance of three different types of switching networks in terms of average blocking probability and the mean time to unreliable operation, as we vary the offered traffic. As a result, T–S–T switching networks with multiple separated space switches exhibit better performance and reliability than those with single space switches.     

离子注入对Cr12MoV钢表面组织结构和力学性能的影响

研究了Ｃｒ１２ＭｏＶ钢离子注入层的显微组织特征及其对表面性能的影响。结果表明，离子注入使Ｃｒ１２ＭｏＶ钢的表面硬度和耐磨性能得到显著改善，且存在着一个最佳的注入剂量，约为３×１０＾１＾７Ｎ＾＋／ｃｍ＾２左右。离了注入在Ｃｒ１２ＭｏＶ钢表面层中形成了大量细小弥散的第二相粒子，并使α－Ｆｅ晶格发生严重畸变，从而引起材料表面强化。     

基于Web的中小型企业销售管理信息系统的设计与应用

针对中小型企业销售管理的现状，利用J2EE架构技术设计了面向中小型企业的销售管理信息系统，该系统具有良好的跨平台性和可移植性，并且经过测试运行，达到了预期的效果。     

复射线展开法分析圆柱面对平面波散射的精度问题

讨论了用复射线展开法计算圆柱面对入射平面波散射时的计算误差特性，提出了控制其计算精度的复射线展开参数选择方法，证实了通过恰当选择展开参数可以有效地提升计算精度、实现误差控制。     

调幅系数为任意值的调幅波研究

本文讨论了调幅系数为任意值的调幅波，给出了它的表达式，频谱与调幅系数，调制效率和信噪比增益的计算公式。     

吸收雷达波包装材料的研究进展

论述了吸收雷达波包装材料的基本组成及其选择原则，在此基础上讨论了吸波材料的吸波原理及影响吸波性能的因素，并指出了吸波包装材料的开发现状和应用进展及其发展万向。     

A study on the degree of deliberation and meditation of cyber poll respondents for nuclear-related decision making

Public participation is essential in each step of the nuclear-related decision-making process. Recently, the electronic systems using the Internet have become quite popular, and have emerged as a good medium for communicating with the public. In this study, a comprehensive utilization of electronic public participation was used to analyze public opinion on a given nuclear-related decision-making process. The degree of deliberation and meditation of the public participating in an electronic poll survey was evaluated, and the decision-making factors representing the personal characteristics of the poll respondents such as age, income, education, residence, degree of knowledge and concern were carefully incorporated when preparing the poll-survey questionnaire for its evaluation. Fuzzy analysis was used to assess and aggregate the responses to each decision-making factor. As a case study, this procedure was used to analyzing public opinion on the location of a low-level radioactive waste disposal facility on the campus of Seoul National University. The results show that there is a tendency of respondents who are on the negative side of the argument to be more deliberate and meditative in their decision-making process than those on the positive side. Knowledge and residence were found to be important decision-making factors.