In order to seek for applications in video coding of Compressed Sensing (CS) and improve the coding efficiency of MPEG-2, a CS and MPEG-2 based improved scheme was proposed. The improved video coding scheme chose the method producing an image with smaller Sum of Squared Differences (SSD) as the final reconstruction method between the standard reconstruction method and the Total Variation (TV) minimization algorithm in the pixel domain, which is based on the fact that the original image has sparser gradient than the residual image. The experimental results show that the proposed scheme is efficient for all kinds of video sequences. The improvement of Peak Signal-to-Noise Ratio (PSNR) is greater than 0.5dB for the sequences with sharp edges, and 0.26dB~0.41dB for sequences with smooth areas or complex textures.

The existence of potential links in sparse networks becomes a big challenge for link prediction. The paper introduced active learning into the link prediction task in order to mine the potential information of a large number of unconnected node pairs in networks. The most uncertain ones of the unlabeled examples to the system were selected and then labeled by the users. These examples would give the system a higher information gain. The experimental results in a real communication network dataset Nodobo show that the proposed method using active learning improves the accuracy of predicting potential contacts for communication users.

All the available geometry theorem provers are not sustainable. A knowledge representation with the general structure and a reasoning algorithm which could deal with all the rules were proposed. According to these ideas, a geometry automatic reasoning platform that could be sustainably developed by the user had been initially implemented. This platform allows the user to add geometric knowledge such as geometric objects, predicates and rules, and provides multiple reasoning algorithms such as forward search method and a part of area method, so it will be more suitable for geometry teaching.

Authentication is an issue of importance in computer communications, and password authentication protocols have been widely utilized due to their great convenience. Recently, Lee et al. proposed a nonce-based remote user authentication scheme using smart cards. In this paper, however, it is found that their scheme is not secure as claimed, and two attacks can be launched to break the scheme.

Considering the characteristics of sensor nodes' limited energy and limited transmission radius, the clustering hierarchy tree routing algorithm based on LEACH was proposed. In cluster construction stage, the optimal candidate cluster heads would become the final cluster heads, which guaranteed the distance between any two heads was far enough and neither of them was in the same area of radius, so the cluster heads were uniformly distributed in the network. In the intercluster communication, cluster heads form a hierarchical tree and the root was Base Station (BS), which reduced the energy consumption of direct data transmission from the head to BS, thereby prolonging the life cycle of the network.