Channel modeling of the closed environment plays an important role in many application scenarios. When there are many obstacles in the space, the traditional ray tracing algorithm has the problem of too many times of finding intersection points in the calculation process, which makes the algorithm calculation efficiency low. Therefore, a ray tracing acceleration method based on space division was proposed. In the method, according to the distribution of objects in three-dimensional space, the static and dynamic space division acceleration methods were combined reasonably, so as to greatly reduce the number of finding intersection points between rays and objects in space, and improve the calculation efficiency of the algorithm. Simulation analysis shows that in the three-dimensional environment with the same prediction accuracy, compared with the original algorithm, the ray tracing algorithm using static space division has the calculation efficiency improved by at least 50.2% as the division level is improved; and compared with the algorithm which only uses static space division, the acceleration method based on the combination of static and dynamic space divisions has the calculation efficiency improved by at least 8.9% on the basis of the improvement above.

Aiming at the problems of long synchronization setup time and poor synchronization stability in classical Gardner timing recovery algorithms, a Gardner timing synchronization recovery algorithm with improved loop structure was proposed. Firstly, two interpolation filters with cubic interpolation and piece wise parabolic interpolation were used to obtain two optimal interpolation sequences. Secondly, the timing errors corresponding to the two interpolation sequences were calculated respectively and the weighted average value was obtained to gain the timing error of the loop. Finally, the weighted average value of two optimal interpolation sequences was used as the loop output. The simulation experiments of two modulated signals of Quadrature Phase Shift Keying (QPSK) and 16 Quadrature Amplitude Modulation (16QAM) were performed. Simulation results show that the synchronization stability of the proposed algorithm is better on QPSK signal. Compared with performing on 16QAM signal, the number of sequences corresponding to the position of the symbols when the loop starts the synchronization is obviously reduced. Additionally by using the propposed algorithm, the convergence radius of the QPSK constellation is about 0.26 when the SNR is -5 dB. Compared with the improved Gardner timing recovery algorithm similar to Frequency and Phase Lock Loop (FPLL), the convergence radius is reduced by 0.08. This algorithm effectively shortens the synchronization setup time, improves the stability of the loop, and can be widely applied in high-speed demodulation system.

To reduce the impact of Programmed I/O (PIO) write latency in PCI express (PCIe) transmission process, too many times of interaction between the host and the embedded processing system and other issues on transmission bandwidth, a Direct Memory Access (DMA) controller based on command buffering mechanism was designed to improve the transmission bandwidth utilization. Using the internal command buffer of the Field-Programmable Gate Array (FPGA), the DMA controller could cache the data transfer request of the PC. The FPGA could dynamically access the storage space of the PC according to its own requirements and enhance the transmission flexibility. At the same time, a dynamic mosaic DMA scheduling method was proposed to reduce the times of host-to-hardware interaction and interrupt generation by merging the access requests of adjacent storage areas. In the system transmission rate test, the maximum write speed of DMA was 1631 MB/s, the maximum rate of DMA read was up to 1582 MB/s, the maximum of bandwidth was up to 85.4% of the theoretical bandwidth of PCIe bus. Compared with the traditional PIO mode DMA transfer method, DMA read bandwidth increased by 58%, DMA write bandwidth increased by 36%. The experimental results show that the proposed design can effectively improve the DMA transfer efficiency, and is significantly better than PIO method.

Adjacent Vertex-Distinguishing Equitable V-Total Coloring (AVDEVTC) of a graph means on the basis of adjacent vertex-distinguishing V-total coloring, the differences between every two colors used in coloring are no more than one. The minimum number of colors used for completing AVDEVTC is called Adjacent Vertex-Distinguishing Equitable V-Total Chromatic Number (AVDEVTCN). A multi-objective optimization coloring algorithm was proposed to resolve the problem of AVDEVTC of the graph. A main objective function and four subobjective functions were designed according to the conditions of AVDEVTC. Every subobjective function was optimized to meet the requirements of the main objective function by the iterative exchange operation of the color set of every vertex on the coloring matrix, thus completed the coloring. Theoretical analysis and experimental comparison show that all of the simple connected graphs within eight vertices have the AVDEVTC, and their AVDEVTCN are between the maximum degree plus 1 and the maximum degree plus 2. The experimental result indicates that the proposed coloring algorithm can correctly calculate the AVDEVTCN of graphs within 1000 vertices in a short period of time.

For the traditional player skill estimation algorithms based on probabilistic graphical model neglect the first-move advantage (or home play advantage) which affects estimation accuracy, a new method to model the first-move advantage was proposed. Based on the graphical model, the nodes of first-move advantage were introduced and added into player's skills. Then, according to the game results, true skills and first-move advantage of palyers were caculated by Bayesian learning method. Finally, predictions for the upcoming matches were made using those estimated results. Two real world datasets were used to compare the proposed method with the traditional model that neglect the first-move advantage. The result shows that the proposed method can improve average estimation accuracy noticeably.

In the design of DBMS,the high performance of DBMS is important.In this paper,a self-tuning model of dynamic-tinning of resource of DBMS was brought forward based on feedback model.This model can adjust system parameters automatically to achieve good performance.It also puts forward the dialog tree,model of relationship of resource,and the arithmetic used to make tinning plan.