基于乱序修正框架的物联网复杂事件检测模型

IoT Complex Event Detection Model Based on Out-of-order Revise Framework

针对物联网应用系统中存在的时间戳乱序问题,给出了物联网语义事件定义,对时间戳乱序问题进行了描述,同时基于混合驱动的空间回收机制,构建了基于哈希结构的复杂事件乱序修正框架,并提出了一种基于乱序修正框架的复杂事件检测算法(ORFCED)。该算法提取事件的2个特征参数来计算哈希地址,利用时间戳特性将事件存入循环单链表进行局部排序,从而解决了时间戳乱序问题。仿真结果表明,所提出的ORFCED算法不仅具有较高的处理正确率和可靠性,而且可以对乱序流及时地作出反应,弥补了现有方法存在的不足。最后通过案例研究验证了所提算法的有效性和可行性。

There are always events with out-of-order timestamps in the Internet of Things （loT） application systems. To deal with the problem, a semantic event definition about IoT was presented and the issue of out-of-order timestamps was also described. Meanwhile, according to the mixed driving space reclaim mechanism, an out-of-order revise frame- work of complex events based on Hash structure was established. What＇ s more, a complex event detection algorithm based on out-of-order revise framework （ORFCED） was proposed. To solve the issue of out-of-order timestamps, the algorithm extracts two characteristic parameters of events to compute the Hash address and stores events into circular linked list in the timestamp order to sort them locally. Simulation results show that the proposed ORFCED algorithm not only can process events with high accuracy and reliability, but also can respond timely to out-of-order streams, which makes up {or the deficiency of the existing methods. Finally, a case study was made, which verifies the effectiveness and feasibility of the proposed algorithm.