针对发生时间戳乱序的RFID原子事件流,文章提出了一种新的复杂事件检测方法。该方法采用在一种特殊的Hash表结构中进行局部排序的方法来解决时间戳乱序问题。文中首先建立了时间戳乱序问题的描述模型;提出了面向时间戳乱序数据流的复杂事件检测算法;在基本算法的基础上添加了基于双时间槽的滑动窗口处理;对Hash表大小等参数对算法效率的影响、基于双时间槽的滑动窗口处理方法的效果进行了实验验证。实验结果表明:算法是有效的;Hash表大小对算法效率影响较为明显;基于双时间槽的滑动窗口处理方法可以显著提高内存使用效率。
Recent RFID(Radio Frequency Identification) complex detection methods always assume that events in RFID data streams are in total time order.But in distributed RFID application systems,the events are always out-of-order.A new method is presented for detecting complex events over out-of-order RFID data streams.In the method,a special hash table is designed.In the hash table,each node of the main chains has a sub-chain.Related primitive events are preserved in the sub-chain in time order.By this method,the or...