Research And Implementation Of Entity Discovery System In Pervasive Computing Environment

Pervasive computing has the characteristics of universality, convenience and adaptation, tightening the relationship among people and their computing environments. In order to implement the convenience, pervasive software and hardware entities should be able to autonomously communicate with each other. Entity discovery service is a software infrastructure to achieve this goal, by maintaining a dynamic view of existing entities in a certain district.Entity discovery is the enhancement of traditional service discovery whose target is just limited in the enterprise network and internet. The main differences between their two can be summarized as follows: in one hand, entities in entity discovery include various hardware as well as software services; in the other hand, entities and their properties are changing much more dynamically. Those differences offer challenges to entity discovery technology, for example, how to describe highly heterogeneous entities, how to perform efficient matching, how to organize large-scale information and how to guarantee their usability in a dynamic environment. Among them, we believe method of entity description and entity matching algorithm should be the most important issues, which this thesis is lay emphasis on.To address the challenges above, this thesis makes a survey on existing entity discovery services, presents an efficient entity searching method and implements an entity discovery system based on this method. The thesis is organized as follows.Firstly, to lay the foundation of effective and flexible entity searching, we present a method to describe entities, which is able to describe functions and attributes of entities precisely.Secondly, we present an entity searching method based on layered concepts. Using the reasoning capability of description logic, the proposed entity searching method can find right entities by matching layered concepts.Thirdly, based on the entity description method, the entity searching method and other mechanisms we proposed to address the remaining challenges mentioned above, we design and implement a complete entity discovery service prototype, StarEDS.Forthly, by performing tests and experiments on StarEDS system, we thoroughly validate the achievements of this thesis.