Self-Organized Public-Key Management for Mobile Ad Hoc Networks Based on a Bidirectional Trust Model

In traditional networks , the authentication is performed by certificate authoritys（CA）,which can＇t be built in distributed mobile Ad Hoc Networks however. In this pa per, we propose a fully self-organized public key management based on bidirectional trust model without any centralized authority that allows users to generate their public-private key pairs, to issue certificates, and the trust relation spreads rationally according to the truly human relations. In contrast with the traditional self-organized public-key management, the average certificates paths get more short, the authentication passing rate gets more high and the most important is that the bidirectional trust based model satisfys the trust re quirement of hosts better.     

正交试验法在颗粒材料堆自组织分析中的应用

颗粒材料堆具有非均质性、非连续性及随机性等内在的独特性质,从而给研究带来很大困难.颗粒材料堆在承载时,其力学性质与颗粒的大小、排布、堆积高度、表面的粗糙程度以及加载速度都有着密切关系.通过采用室内正交实验,利用自制的设备,研究了堆积高度、粒径和加载速度3个因素在不同水平下对颗粒材料堆自组织现象的影响.