一种关注消息时效性的机会社会网络中节点传播能力分析模型

摘要

Traditional methods for evaluating node importance in sustaining the overall network topology or information dis-semination are widely studied,while most of them are not applicable to dynamic settings where connections among nodes change frequently over time.This paper treats an opportunistic mobile social network as a time evolved,dynamic graph and proposes an ef-fective scheme to calculate the relative nodal dissemination capability based on the contact history.In particular,we analyze the node importance in forwarding messages in more general settings where messages are time-dependent and become less important or out of date over time.To this end,we take a dynamic walk counting approach to calculate all possible temporal-spatial routes from a node to any other node by using a method of down-weighting of length.Since the age of a message increases with time,the old walks are discounted to represent the fading influence on the destination nodes.Experiments are conducted based on 4 real-world trace datasets,and the results show that our analytical result is effective at ranking the capabilities of nodes in disseminating or receiving the time-dependent messages.%当前评估节点传播能力的工作大多针对静态网络。本文采用演化图模型对机会社会网络进行刻画，通过将传统通路（walk）的概念和静态图中的 Katz 中心性度量扩展到动态网络中，提出了一种基于历史相遇记录评估节点消息分发能力的方法。进一步，针对消息的时效性特性，本文提出了消息随时间推移效用递减的节点传播能力分析模型，该模型考虑了消息所有可能经历的空间和时间通路，并沿时间方向向下加权以描述消息时效性递减效应，可用于有效计算和预测节点的消息转发能力。本文的结论通过真实数据得到了验证。