基于SIS模型的网络舆情无监督预警机制研究

Unsupervised Alert Mechanism for Message Propagation Based on SIS Model

【目的/意义】随着网络信息传递的快速增长,对网络舆情的实时监控日益重要,由此带来了不断攀升的管理成本。因此利用无监督的舆情预警来替代人工监控具有普遍的实践意义。【方法/过程】基于SIS的传染病模型,具体分析了舆情传播的时间演化特征,定义了舆情爆发的临界时刻。通过对舆情扩散系数以及遗忘率的分析,实现了以无监督预警时间为目标的优化策略。【结果/结论】优化结果显示:预设的扩散系数并非越小越好,在无监督预警时间达到最大时,存在一个最优的扩散系数。同时,最优扩散系数可以随着舆情传播环境的变化实现动态的自适应调整,始终保持无监督预警效用的最大化。

【Purpose/significance】With the rapid growth of message transfer on Internet,the real-time monitoring of message propagation is getting more and more important.However,it results in increased cost of management.Therefore,it is of general practical meaning to replace the manual monitoring by unsupervised propagation alert.【Method/process】Based on the SIS epidemic model,the characteristics of time evolution of message propagation on Internet are analyzed,as well as the definition of the critical time of burst.By using the coefficient of message diffusion and the rate of forgetting,we build up an optimized strategy for extending the span of unsupervised alert.【Result/conclusion】The optimized results show that the span of unsupervised alert is not always increasing as the diffusion coefficient decreased.There exists an optimal diffusion coefficient maximizing the span.Moreover,the optimized diffusion coefficient is self-adapted when the message propagation circumstance changed.Therefore,the effect of the unsupervised alert strategy can be maximized all the time.