In view of the problem that ViBe (Visual Background extractor) algorithm sometimes produces “ghost” when detecting moving targets and the misdetection problem of moving targets caused by the interference produced by the algorithm in the target detection with dynamic background, an improved ViBe algorithm was proposed based on the techniques of three frame differencing and morphological post-processing carried on the key frames extracted by Color Layout Descriptor (CLD). Firstly, the video key frame images were extracted by CLD. Secondly, three frame differencing was performed on the selected key frame images. The background model containing the moving target was filled by the difference results, obtaining the real background image. Thirdly, the moving target was detected, so as to eliminate the “ghost”. Finally, the morphological processing technique with adaptive threshold was added in the updating stage of background model to eliminate the interference information in the dynamic background model. The experimental results show that the proposed algorithm has superiority in avoiding ghost and anti-dynamic background interference in moving target detection, and when the similar measurement threshold is selected from 0.67 to 0.72, the accuracy of the algorithm can be as high as 99.4%, indicating that the algorithm can ideally detect the position information of the moving target.

A distributed simulation approach was proposed for discrete-events simulation with considerable amounts of events between logical processes. The proposed approach employed a time-driven method to simulate occurrence of discrete-events, using Remote Procedure Call (RPC) to describe the interaction between simulation members. In this approach, barrier synchronization objects were deployed for time synchronization in simulation advancement, in order to ensure the correctness of the causal ordering. Results obtained from the experiments show that the proposed approach can correctly and promptly handle large number of events, providing accuracy guarantee and efficiency improvement of the simulation model.

Multi-application card operation system leads the trend of the development in smart card. The key problems include dynamic download, refresh and deletion of applications. In this paper, the hierarchical construction of card operation system and the architecture of Multi-application system were analyzed and the solution to the Multi-application management platform was presented. Then the design of the Application Operation Data(AOD) and the Application Operation Certificate(AOC) were also given in detail. Finally the security of this system wais discussed. With the solution, the dynamic download, refreshment and deletion in Multi-application card system can be accomplished safely.