机务设备油液监测及故障诊断系统

油液监测与故障诊断是机车安全运行的根本保障,介绍机务设备油液监测及故障诊断系统的总体要求、系统功能以及各种功能的实现.     

A Layer-Cluster Key Agreement Protocol for Ad Hoc Networks

Mobile ad hoc networks create additional challenges for implementing the group key establishment due to resource constraints on nodes and dynamic changes on topology. The nodes in mobile ad hoc networks are usually low power devices that run on battery power. As a result, the costs of the node resources should be minimized when constructing a group key agreement protocol so that the battery life could be prolonged. To achieve this goal, in this paper we propose a security efficient group key agreement protocol based on Burmester-Desmedt (BD) scheme and layer-cluster group model, referred to as LCKM-BD, which is appropriate for large mobile ad hoc networks. In the layer-cluster group model, BD scheme is employed to establish group key, which can not only meet security demands of mobile ad hoc networks but also improve executing performance. Finally, the proposed protocol LCKM-BD are compared with BD, TGDH (tree-based group Diffe-Hellman), and GDH (group Diffie-Hellman) group key agreement protocols. The analysis results show that our protocol can significantly decrease both the computational overhead and communication costs with respect to these comparable protocols.     

车站旅客电子导向系统软件设计

旅客电子导向系统是车站引导旅客进行登乘的重要基础设施.介绍车站旅客电子导向系统软件部分的组成、功能和模块划分,数据库设计以及实现.     

基于PKI与PMI的访问控制在企业信息系统中的应用

安全是企业信息系统中面临的重要问题,PKI和PMI的结合可以很好地解决信息系统中的安全问题.但是目前还没有切实可行的专门在信息系统中应用PKI和PMI的方案.文中在分析PKI,PMI和 RBAC特点的基础上,提出了一种基于PKI与PMI的访问控制在企业信息系统中的应用方案,并对其访问控制模型进行了分析与设计,描述了使用PKI与PMI实现企业安全系统的基本过程,并且给出了相应的实例说明.