Two Bandwidth Packing Algorithms for the Centralized Wireless Network and Their Average-case Analysis

This paper presents a detail analysis of two bandwidth packing algorithms, used for processing connection requests in the centralized wireless network. Each call comes with a specific bandwidth request. A request can be satisfied only if there is sufficient bandwidth available during resource scheduling and allocation. Unsatisfied requests were held in a queue. The metric of bandwidth utilization ratio was used to quantify the performance of our algorithms. By theoretical analysis, our algorithms can improve the average bandwidth usage ratio significantly, about 8%~10% without adding much computation complexity. Moreover, our algorithms outperform next fit with fragmentation (NFF) algorithm when the bandwidth resource is scarce. In this paper, the contributions follows: Introducing bandwidth packing problem into wireless network; Proposing two new bandwidth packing algorithms for wireless network where the complicate scheduling algorithms are prohibited; Studying the average performance of our algorithms mathematically, which agree well with the simulation results.     

城市轨道交通车辆关键系统可靠性研究

研究城市轨道交通车辆的可靠性对保证其安全运营有着重要意义。介绍可靠性分析的相关理论;以广州地铁一号线车辆为对象进行故障统计分析,选择车门系统、信号接口系统和牵引/电制动系统为车辆关键系统,确定关键系统的故障分布模型,计算得出关键系统的可靠性指标函数,为城市轨道交通车辆可靠性评价与维修提供决策参考。     

地铁车辆信息网络数据库在车辆维修管理中的应用

介绍如何利用计算机局域网开发“车辆信息数据库”,以及在开发中所需的基础信息和应该具有的各项功能。并说明它在投入运行后对广州地铁一号线的车辆维修管理所起到的作用。     

生命的呼唤

生命只有一次,然而,生命在某些时候却显得无比脆弱,特别是在面对猝不及防的交通事故时,一个个鲜活的生命转瞬就消逝了,不仅给人带来无尽的灾难与痛楚,更多的是让人们陷入那无边的痛苦与黑暗之中.     

计划修与状态修在广州地铁车辆维修运用中的必要性和适用性

介绍了广州地铁车辆的特点和运用现状，分析了当前条件下地铁车辆维修运用中采用计划修和状态修相结合的维修模式所具备的理论基础和现实要求，阐述了广州地铁车辆维修模式应包含的理念及内容。     

地铁车辆信息网络数据库在车辆维修管理中的应用

介绍如何利用计算机局域网开发“车辆信息数据库”，以及在开发中所需的基础信息和应该具有的各项功能，并说明它在投入运行后对广州地铁一号线的车辆维修管理所起到的作用。     

可靠性管理在城市轨道交通车辆全寿命周期内的应用

通过对RAMS(可靠性、可用性、可维修性和安全性)中可靠性相关概念的介绍,从城市轨道交通运营商的角度出发,说明可靠性管理在控制车辆质量方面所能发挥的重要作用.针对可靠性管理在车辆全寿命周期内的应用分析,阐述了在车辆设计和制造阶段需要开展的可靠性工作,并提出了在车辆维护阶段采用基于可靠性的新型维修模式的优越性和必要性.分析表明,可靠性评估对城市轨道交通运营商在提高车辆安全性、可靠性,优化维修模式等方面可起到重要的促进作用.     

Identifying Proper Names Based on Association Analysis

The issue of proper names recognition in Chinese text was discussed. An automatic approach based on association analysis to extract rules from corpus was presented. The method tries to discover rules relevant to external evidence by association analysis, without additional manual effort. These rules can be used to recognize the proper nouns in Chinese texts. The experimental result shows that our method is practical in some applications. Moreover, the method is language independent.