Applied Mechanics and Materials Vols. 599-601

Abstract: Because GLONASS and GPS are different in system, data processing of GLONASS carrier phase difference is quite different from that of GPS, requiring special methods. Based on eliminating the impact of the relative deviation of receiver clock, a new mathematical model of GLONASS phase difference is introduced in this article. This new model can make full use of existing GPS data processing technology to complete GLONASS data processing work conveniently.

Abstract: The optimal path planning plays an important role in the satellite navigation system. This paper uses the Dijkstra algorithm, which gives a shortest path first, to find a more effective travel decision. The decision combines the Dijkstra algorithm with the real-time traffic information and gives an effective travel plan. This system is developed under C# environment, achieves the goals of travel path planning and traffic guidance, and can supply a variety of travel plan to the traveler according to the difference influence factors.

Abstract: In the past, various methods have been used to estimate the parameters in the nonlinear three-parameter Muskingum model to allow the model to more closely approximate a nonlinear relation compared to the original two-parameter Muskingum model. In this study, the particle swarm optimization algorithm based on the organizational evolutionary (OEPSO), which the evolutional operations are acted on organizations directly in the algorithm, and gained the global convergence ends through competition and cooperation, and overcome the shortcomings of the traditional PSO, is introduced. The OEPSO is proposed for the purpose of estimating the parameters of nonlinear Muskingum routing model. The performance of this approach is compared with other reported parameter estimation techniques. Results of the application of this approach to an example with high nonlinearity between storage and weighted-flow, show that the OEPSO approach is efficient in estimating parameters of the nonlinear routing models.

Abstract: Traffic jams increasingly threaten the normal city traffic, so our paper analyzes the state of the existing road traffic congestion, road traffic congestion found in the state is a relatively vague and random dynamic data model. Based on these two characteristics, we propose a road traffic congestion degree assessment model based on Bayesian algorithm. Based on the theoretical analysis of Bayesian algorithms to improve the processing efficiency of the algorithm to construct the road traffic congestion degree evaluation model based on Bayesian algorithm set, and the simulation experiments.

Abstract: In Message-Oriented Middleware with Pub/Sub model on TT&C computer, the clients are only responsible for sending messages to Pub/Sub services, the matching and forwarding of messages should be executed by Pub/Sub service. so the efficiency of matching algorithm is an important factor influencing the system real-time performance. A matrix matching algorithm is proposed in this paper. Firstly put all subscriptions under one theme into a matrix (m×n)of 0, 1 with preprocessing, m means the number of subscriptions, n means the total number of predicates. When one event is released, if it does not match with a predicate, delete all subscriptions containing the predicate. Experiments show that the efficiency of matrix matching algorithm is higher than traditional predicate counting algorithm.

Abstract: On the MapX ActiveX environment, an embedded Beidou satellite navigation system is established. This system is developed under the visual programming development environment (C#2008), achieved satellite signal receiving. The positioning information receiving and displaying is realized by a Beidou navigation module and communicated with the computer via the serial port COM component.

Abstract: The wind is the main factor to influence the propagation of gas in the atmosphere. Therefore, the wind signal obtained by anemometer will provide us valuable clues for searching gas leakage sources. In this paper, the Recurrence Plot (RP) and Recurrence Quantification Analysis (RQA) are applied to analyze the influence of recurrence characteristics of the wind speed time series under the condition of the same place, the same time period and with the sampling frequency of 1hz, 2hz, 4.2hz, 5hz, 8.3hz, 12.5hz and 16.7hz respectively. Research results show that when the sampling frequency is higher than 5hz, the trends of recurrence nature of different groups are basically unchanged. However, when the sampling frequency is set below 5hz, the original trend of recurrence nature is destroyed, because the recurrence characteristic curves obtained using different sampling frequencies appear cross or overlapping phenomena. The above results indicate that the anemometer will not be able to fully capture the detailed information in wind field when its sampling frequency is lower than 5hz. The recurrence characteristics analysis of the wind speed signals provides an important basis for the optimal selection of anemometer.

Abstract: Owing to the satellite signal strengths of GNSS is so low that it is interfered with powerful signal, that how to effectively resist interference is becoming a problem.In this paper,first LCMV algorithm based on the power-inversion adaptive array is deduced from theory in certain mathematical model ,what’s more ,for avoiding computing the inverse of matrix, LCMV algorithm is improved and then is verified through the Matlab-simulation .Last,the hardware design is given for the realization of this algorithm.

Abstract: A design scheme based on IPSec VPN Service in VMware simulation platform was proposed. At first, this paper introduces the virtual machine and the working principle of IPSec VPN. Using VMware to construct a network simulation platform. Next,Through Routing and Remote Access Service、VPN Service of Windows Server 2008′s, the route between subnets was implemented. At last, the simulation experimental results show that the design of stable operation, high safety, no need of special routing equipment, and has low cost, easy to implement, is a safe, cheap, high performance design solutions.

Abstract: Discovery mechanism help users quickly identify instruments and acquire their information. LXI specification requires instrument has two discovery methods: one based on VXI-11 protocol and the other based on mDNS protocol, describes the principle of these discovery methods and analyzes their respective advantages and disadvantages. The verify the function requirement of discovery methods, and the result indicates that both of them meet the expected requirement.