The knowledge in the closed-loop lifecycle management system is independent and can't be shared. In order to solve the problems, aiming at the characteristics of the closed-loop lifecycle, a new knowledge integration and semantic annotation method was proposed. Firstly, the connotation of knowledge integration and semantic annotation in closed-loop lifecycle management system was expatiated briefly. Secondly, a multi-dimensional and multi-level knowledge integration framework was constructed by using ontology technology for low temperature plasma equipment. Then, on the above basis, a computing method of extracting and matching the document semantic vector and ontology semantic vector was designed. The knowledge document semantic annotation of one sub-system in low temperature plasma equipment was completed. Finally, the test experiments were designed and verified. The experimental results show that, by using knowledge document data set in the closed-loop lifecycle management system to complete the semantic annotation, the average accuracy rate of the proposed method is 84%, and its average recall rate is 79%. The proposed knowledge integration and semantic annotation method can realize the sharing and reuse of the knowledge document in the closed-loop lifecycle management system.

To solve the problems that there are differences in presentation and transmission of sensor network data and the application requirement cannot be satisfied by single data source, a method of publishing sensor network data as linked sensor data was proposed. Based on the analysis of linked sensor data publishing methods, firstly, the technology of ontology annotation was used to add semantic information to sensor network data; secondly, a method that queried linked data based on the set of concept group with inheritance relations to find Related Web Datasets (RWD), and a method that compared the similarity of graph based on heuristic property to build links between sensor network data and related datasets on Web were put forward; at last, a Linked Sensor Data Publishing System (LSDPS) was built. Comparing LSDPS with other classical linked sensor data publishing systems, the accuracy of building Resource Description Framework (RDF) links among datasets was raised about 9%. By publishing sensor network data as linked sensor data, the applications can not only understand and take advantage of sensor network data, but also obtain related resource according to RDF links among linked sensor datasets.