This paper proposes a novel temporal Unequal Error Protection(UEP) scheme for coding and transmission of real-time video over erroneous channels. The scheme introduces a low complexity frame-level distortion model to estimate video transmission distortion. Then combed with rate control algorithms, it calculates the optimal source coding and channel protection strategy by simply searching of QP frame by frame. Extensive simulations show that compared with previous schemes, the proposed scheme not only has low delay and moderate computation complexity, but also improves the quality of reconstructed video sequences significantly and reduces the fluctuation of quality between different reconstructed frames.
In order to solve the problem of IMS heterogeneous wireless networks handoff delay, an integration resolution of IEEE 802.21-defined Media Independent Handover(MIH) and IMS architechture is proposed. An algorithm of Markov Decision Process(MDP) based multipath redundant transmission handover is presented, through which seamless handover in IMS is realized. NS-2 simulation results prove that the algorithm compared with the traditional vertical handover algorithm, the effective data transmission rate, handover times and handover stability show a clear advantage.
To solve the problem of deterioration of system performance for the three analog front-end non-ideal factors, such as Carrier Frequency Offset(CFO), IQ imbalance and Sampling Frequency Offset(SFO), in Orthogonal Frequency Division Multiplexing(OFDM) system, this paper proposes a novel joint estimation and compensation algorithm, which estimates and compensates CFO and IQ imbalance in time domain, while Residual Carrier Frequency Offset(RCFO) and SFO in frequency domain. Result shows that, compared with some of the traditional algorithms, the algorithm uses fewer data supporting resources and improves the estimation accuracy, even with large values of non-ideal factors, the proposed algorithm is still able to provide a low bit error rate.
In this paper, an effective classifiable prediction mechanism according to the degree of motion vector prediction is suggested for more fast motion estimation, which classifies the motion vectors as no predictable motion vector, medial predictable motion vector or high predictable motion vector, then different proposed search schemes are adopted for motion estimation. Experimental results show the proposed algorithm reduces the prediction error and has a significant computational speedup compared with other algorithms, but offers a similar, even better performance.
Input-dependent loops can cause the problem of path explosion in symbolic execution, a method based on induction variable for analysis of loop dependence is proposed in this paper. By recognizing the loop induction variables and symbolic expressions, it is combined with the bound conditions to generate feasible path constraint for induction variable branches. Induction variable dependence of nested-loop is solved by symbolic affine analysis. It can generate test cases which can cover the branches of induction variables without loop unrolling. Test results show that by this method, two array access violations of the open source tools Libxml2 are found in while loops.
This paper proposes a color palmprint feature extraction algorithm, combined with four classical algorithms and Octonion BP neural network, to extract palmprint line from color palmprint image. The palmprint line image is decomposed by the two-dimensional wavelet, which is used the octonion vector product representation algorithm to match. Experimental results show that palmprint lines can be extracted well by the extraction algorithm, and the recognition rate of the algorithm is 96%