IP multimedia subsystem (IMS) technology and its application in power system 并列题名：IP multimedia subsystem (IMS) technology and its application in power system Hilbert-Huang transform and its applications in power system Intelligent control and its applications in power systems 并列题名：Hilbert-Huang transform and its applications in power system 并列题名：Intelligent control and its applications in power systems Multimedia communication technology and application for IP network