Focusing on the problem of Virtual Machine Placement (VMP) in heterogeneous cloud environment, a Resource Demand Distribution Feature based Placement Algorithm (RDDFPA) for virtual machines was proposed. Firstly, a method of describing virtual machine requirements and physical machine configuration based on scale factor of CPU resource and memory resource was established. Based on the scale factor, all the virtual machines were sorted. Secondly, by analyzing the proportion relationship of virtual machine requirements and physical machine configuration in the CPU resources and memory resources, the proportion demarcation point was determined, and the partition of virtual machine set was completed. The requirement proportion of matched physical machines with different configurations was reflected by the size of each virtual machine subset.Finally, by using the heuristic algorithm such as the First Fit algorithm, the virtual machine subset was placed on the subset of physical machines with matched configuration. Theoretical analysis and simulation experimental results show that, compared with the total number of physical machines with any single configuration, the total number of physical machines required by the proposed algorithm is reduced by 2%-17%.The proposed RDDFPA can determine the number of physical machines with various configurations according to the distribution of virtual machine resource requirements, and efficiently complete the placement of virtual machines, which can improve the resource utilization rate and reduce the system energy consumption.

To solve the problem of location verification caused by collusion attack in Vehicular Ad Hoc NETworks (VANET), a multi-round vote location verification based on weight and difference was proposed. In the mechanism, a static frame was introduced and the Beacon messages format was redesigned to alleviate the time delay of location verification. By setting malicious vehicles filtering process, the position of the specific region was voted by the neighbors with different degrees of trust, which could obtain credible position verification. The experimental results illustrate that in the case of collusion attack, the scheme achieves a higher accuracy of 93.4% compared to Minimum Mean Square Estimation (MMSE) based location verification mechanism.

The fourth-order entropy consistent schemes were proposed for one-dimensional Burgers equation and one-dimensional Euler systems. Semi-discrete method was used in time, the fourth-order Central Weighted Essentially Non-Oscillatory (CWENO) reconstruction was utilized in space and the Ismails numerical flux function was introduced for the new algorithm. The new scheme was applied for the static shock wave, the Sod shock tube and strong rarefaction wave problems. The numerical results were compared with their corresponding exact solutions and the other existing algorithms results. According to the results, this new method has higher resolution than Roes algorithm, the central upwind schemes and Ismails method have. Moreover, the new algorithm can accurately capture the shock waves and the rarefaction waves without non-physical oscillations. In a word, it is a feasible and accurate numerical method for one-dimensional Burgers equation and one-dimensional Euler systems.

To solve the problem of poor portability and low load capacity in network management system based on C/S model, a kind of Ethernet Passive Optical Network (EPON) network performance management system based on Web was designed and implemented. The system used SNMP4J library to develop underlying application, adopted Struts+Spring+Hibernate (SSH) framework based on Model-View-Controller (MVC) model to realize separation of user interface, application business logic and data access logic, and realized the acquisition, statistical analysis and display of the system related performance parameters. The test results indicate that performance alarm reporting delay and single operation response time of the system are less than that in the "China Telecom mobile service network management system norms—total volume (v1.1)" standard.

This paper advanced the Central Weighted Essentially Nonoscillatory （CWENO)-type entropy consistent schemes to simulate the two-dimensional conservation laws of the initial boundary value problem. The numerical results were analyzed and compared with the exact solutions. It is pointed out that the courant-friedrich-lewy can attain 0.6 and shock transition zone is one or two cells. The results indicate that the new numerical method in this paper has high-resolution and strong stability.

In this paper, a new coding scheme was proposed, which was based on the sequence of its complete binary tree. The scheme is easy to realize and only one positive integer is needed to express the position of the node in XML tree. The time-bounding of identifying the ancestor-descendant relationships is only O(log n). It also supports XML document update. In the scheme, the length of the code is short.