河网中具有时空关系的异常事件在线检测

当网络异常事件发生时,传感器节点间的时空相关性往往非常明显.而现有方法通常将时间和空间数据性质分开考虑,提出一种分散的基于概率图模型的时空异常事件检测算法.该算法首先利用连通支配集算法(CDS)选择部分传感器节点监测,避免监测所有的传感器节点;然后通过马尔可夫链(MC)预测时间异常事件;最后用贝叶斯网络(BN)推测空间异常事件是否出现,结合时空事件来预测异常事件是否会发生.与简单阈值算法和基于贝叶斯网络算法对比,实验结果表明该算法有高检测精度、低延迟率, 能大幅降低通信开销,提高响应速度.

Online abnormal event detection with spatio-temporal relationship in river networks

When the network abnormal event occurs, the spatial-temporal correlation of the sensor nodes is very obvious. While existing methods generally separate time and space data properties, a decentralized algorithm of spatial-temporal abnormal detection based on Probabilistic Graphical Model (PGM) was proposed. Firstly the Connected Dominating Set (CDS) algorithm was used to select part of the sensor nodes to avoid monitoring all the sensor nodes, and then Markov Chain (MC) was used to predict time exception event, at last Bayesian Network (BN) was utilized in modelling the spatial dependency of sensors, combining spatio-temporal events to predict whether the abnormal events would or would not occur. Compared with the simple threshold algorithm and BN algorithm, the experimental results demonstrate that the proposed algorithm has higher detection precision, and low delay rate, greatly reducing the communication overhead and improving the response speed.