In this study, the junction temperature (Tj) and thermal resistance (Rth) of five high-power multi-chip COB (chip-on-board) LED packages with different chip spacings were compared. The actual Tjwas measured by an IR camera and compared with the simulation results from a computational fluid dynamics (CFD) software. In addition, the effects of heat slugs with different thermal conductivity, heat sinks of various thicknesses, chip size, and forced convection cooling on the Tjand Rthof high-powered LED components were investigated. The experimental results show that smaller chip spacing resulted in higher Tjand Rth. The heat dissipation performance can be improved by using a heat slug with a high thermal conductivity; and increasing the thickness of the heat sink, or employing forced convection cooling.

When a disaster occurred in a city, the most important thing is succors and equipment of rescuing arriving at the disaster spot rapidly. We bring up a method of emergency traffic commanding based on GIS and GPS in this paper. The wrecking car installed mobile information terminal transmits the GPS real-time position information to the command center. The command center setups GIS platform, and sends an optimum route of arriving at the disaster spot to the wrecking car based on the condition of real-time traffic, then sends the signal controlling sequence to the traffic signal light of intersection on this optimum route in turn, in order to create “Green Wave” for wrecking car and make it arrive at the disaster spot rapidly.

With the rapid development of wireless network technology, wireless networks have been widely used in many fields due to the flexibility of wireless access. However, in the field of video transmission, because the link state is instability and the transmission is easily interfered in wireless networks, the quality of video transmission is affected badly. In fading and shadowing channels, some users can’t watch the video normally. This paper provides an adaptive QoS solution of real-time video stream in wireless network, by adding a relay server it can provide multicast or unicast video stream satisfying multiple QoS for users with different network state. This solution has been successfully applied in Qingdao Public safety emergency video surveillance system.

Moving object detection and feature extraction algorithm in video sequences are discussed in this paper. There are several problems in moving object detection and extraction from outdoor video surveillance, that is, moving object detection algorithm is easily interfered by background of video monitor, the feature of moving object is difficult to extract from video source, and the vibration of picture frame in outdoor video surveillance causing by wind factors effects the incorrect extraction of the moving object. The vibration causing by wind factors was corrected and an enhancement inter-frame difference algorithm based on difference histogram threshold selection is presented in this paper. The experiment results prove that this method can detect and extract the moving object accurately and efficiently, and it can meet the needs of real-time detection.