This paper enhances the reliability of the data communication mechanism in GMPRS Logical Link Control(LLC) protocol, to address the issues of long delay and high bit error rates over GEO link. It proposes RBM-ARQ algorithm based on bitmap for reliable data communication. RBM-ARQ enhances the recovery of channel impairment by keeping the terminals updating the buffer status. Simulation results show when retransmission time and count are set properly, LLC layer throughput gets better and delay becomes smaller, and compared with GMPRS LLC layer acknowledged data transfer, RBM-ARQ algorithm achieves better performance and the better recovery of data.
A novel visual tracking algorithm based on sparse representation is proposed to solve the problem of occlusion. The tracked object is described using the sparse representation method, and the image Gabor-features are used to construct the object dictionary and occlusion dictionary. The optimal sparse coding coefficients are obtained via l1-norm minimization. The tracking algorithm is designed in a particle filtering framework. The occlusion is judged according to the distribution of nonzero values in sparse coding coefficients. Under occlusion, the particles’ weight is calculated based on the approximation residual of observation by sparse representation. A template reliability evaluation method is introduced to suppress the drift during the object dictionary update. Experimental results show that the proposed algorithm can handle occlusion efficiently, and be robust to pose and illumination variations.
In systems with delay constrained traffic, the Channel State Information at the Transmitter(CSIT) is obtained slot by slot. The precoder design exploiting this incomplete CSIT is studied in this paper. An Optimized(OPT) power allocation algorithm based on the quantization of received power and a suboptimal but much simpler Hybrid Power Allocation(HPA) algorithm are proposed. Numerical results verify the efficiency of the proposed designs. For example, in a system with delay constraint 4 slots, the OPT and HPA precoders improve the system performance by 6.1 dB and 5.8 dB respectively.
Mutual information game theory is introduced in the decision-making process of the cryptographic chips designers (defense party) and the attacker, a risk quantification evaluation model based on mutual information game is built. It investigates the attack and designs tactics choice to security risks, and combining with the quantitative methods of the mutual information, gives the optimization tactics selection method of the both sides of attack and designs on Nash equilibrium conditions, gives the mutual information benefits of the both sides of attack and designs on Nash equilibrium. Through the case analysis, the validity of the strategy is proved.
Aiming at the encryption system with lower security requirements, this paper puts forward a symmetrical key automatic changing cryptography scheme based on simple hybrid selection coding, with the combination of unilateral canonical Huffman coding and fixed-length coding. The statistical results of plaintext are used as their own encrypted key and coding basis, which makes the scheme to be easy to implement and calculate and of cost low. It is proved that when the keys are completely unknown, the cracking of the encryption system has great difficulty.
A pre-transfer method based on Segment Selection Not Used Recently(SSNUR) algorithm is presented to solve low availability caused by the traditional copy technology in the virtual machine hot standby. The used memory pages are pre-transferred in the running phase of the virtual machine, in order to reduce the number of memory pages to copy in the shutdown phase, and SSNUR algorithm is proposed to select the pages need to copy in order to reduce the repetition rate of pre-transfer and stop-transfer. Experimental results show that the pre-transfer Remus compred with the original method has obvious advantages when the virtual machines have heavy load and long intervals, and downtime can be reduced up to 23.37%.
The Cellular Automata(CA) model for the problem by applying the CA theory and a min-cut partitioning algorithm based on the model for bisecting weighted hypergraph are proposed. In the model, the vertex of hypergraph can be considered as the cell, the vertices of adjacent hypergraph are denoted by the CA-neighborhoods and each cell’s state represents the partitioning which the corresponded vertex belongs to. Furthermore, the two-dimensional auxiliary array is designed for counting the vertices of each hypergraph in different partitions. The rapid method of calculating the cell’s gain and the cut’s size are proposed to avoid traversing each vertex of hypergraph. Experimental results show that the algorithm not only can find the better partitioning of weighted hypergraph than the move-based method and graph parti-tioning algorithm, but also can reduce the time complexity and the space complexity.