中文摘要：

无线射频识别（RFID）采用唯一的电子标签识别物理对象，可高速收集大量目标数据．为向各类应用提供语义信息，RFID系统需从收集的数据中检测用户自定义的复合事件．通过提出一种基于Petri网的RFID事件检测方法，引入形式化的ED-net模型描述复合事件语义，并以此为基础实现一种事件检测方法．ED—net模型是对传统Petri网的一种扩展，提供了描述用户自定义类型、函数及表达式的能力，可精确描述RFID复合事件的属性及时域、非时域、参数化等约束条件．通过对RFID事件形式化描述，各种RFID事件可以统一在ED—net模型，并可自动化进行检测处理，避免了不同复合事件间公共子事件重复检测的问题．最后，经过实验测试和分析，验证了该形式化方法的有效性及其优势．

英文摘要：

Radio frequency identification （RFID） provides fast collection of large volume of data and can be used to identify physical objects with unique IDs. In order to provide semantically meaningful data to different applications, RFID data need to be processed to discover user-defined complex events. The Petri-net-based method for the detection of complex events in RFID is proposed. A model named ED-net is introduced to specify semantics of complex events, which is also taken as the basis for the implementation of an event detector. Formal model ED-net is an extension of ordinary Petri net, providing user-defined types, functions and expressions, which are suitable for the precise description of attributes and constraints of RFID complex events, with non-temporal, temporal and parameterized constraints. Taking advantage of the token-flow mechanism of ED-net, we develop a step-by-step detection method that signals the occurrence of a complex event as soon as a corresponding place in ED-net is marked. Through modeling all the events to be detected in one EDnet model, multiple detections of common sub-events of different complex events are avoided. Finally, the experimental evaluations demonstrate the obvious reduction of average complex event detecting latency and CPU resource occupation The efficiency and advantages of this detection method are verified.