针对传统基于射频识别技术(radio frequency identification,RFID)的克隆检测方法面对供应链动态变化、标签误读的局限性,提出一种简单、有效的基于轨迹的克隆检测方法。该方法通过在标签中写入验证序列,使得随着标签随产品在供应链中流动,正版标签和克隆标签因验证序列的不断更新而出现不同,而且标签中的验证序列随时间变化会呈现一定的规律,于是形成一条序列轨迹,结合标签事件信息中业务动作的一致性形成2条轨迹,即双轨迹。该方案通过评估2条轨迹的正确性来发现克隆,在评估克隆存在时充分考虑了标签误读、误写、事件丢失以及错误运输。使用Arena对供应链进行建模和仿真。仿真表明,该方案对供应链动态变化具有灵活性,同时在牺牲较小通信量的情况下,有效地提高了检测性能。
The outbreak of hotspot in social network may contain complex dynamic genesis. Using user behavior data from hotspots in social network, we study how different user groups play different roles for a hotspot topic. Firstly, by analyzing users' behavior records, we mine group situation that promotes the hotspot.Several major attributions in a hotspot outbreak, such as individual, peer and group triggers, are defined formally according to the view-point of social identity, social interaction, retweet depth and opinion leader. Secondly,for the problem of the uneven and sparse data in each stage of hotspot topic's life cycle, we propose a dynamic influence model based on grey system to formalize the effect of different groups. Then the process of hotspot evolution driven by distinct crowd is showed dynamically. The experimental result confirms that the model is able not only to qualify users' influence on a hotspot topic but also to predict effectively an upcoming change in a hotspot topic.
针对目标监测型无线传感网中源节点位置隐私保护问题,提出一种基于幻影路由的增强型源位置隐私保护协议(enhanced protocol of source-location privacy preservation based on phantom routing,ESLBPR)。该协议通过一种扇形区域划分方案以及扇形域中改进型幻影路由机制,较好地保护了源节点的位置隐私。该协议具有以下优势:面对较强攻击者,不会发生方向信息泄露;相邻时序产生的幻影节点间的距离及路由至相同幻影节点的可能性得到控制;产生数量众多,分布多样化的幻影节点;幻影节点与源节点的距离进一步增大。理论与仿真实验表明,与已有的源位置隐私保护协议相比,ESLBPR协议在能耗不显著增加的情况下,使得源位置隐私保护的安全性能大幅度提升。
