Applied Mechanics and Materials Vols. 571-572

Abstract: The multipath in the inter-spacecraft microwave ranging system is the short-delay multipath generally. The performance of existing multipath mitigation algorithms degrade in the short-delay scenario, and therefore an adaptive filtering algorithm based on variable step-size LMS is exploited for estimating the parameters of multipath signals. Firstly, the equation of variable step-size LMS is deduced. Then, the signals parameters are estimated recursively though the adaptive filtering algorithm. Multipath elimination is performed by substracting the estimated multipath effects from the measured correlation function. Simulation results validate that the proposed method is superior to the existing algorithms in the aspect of convergence rate and ranging accuracy for the short delay multipath. Therefore, it is a viable solution for achieving high accuracies measurements in microwave ranging system with short-delay multipath.

Abstract: Spectrum assignment and power assignment are both key technology to use spectrum resource for cognitive radio networks effectively. In this paper, an effective joint resources assignment method is proposed. The objective is to maximize the system throughput and to guarantee the quality of service for the users simultaneously. The method is based on harmony search algorithm and graph coloring theory. It gives a more proper representation of the interference between the users in our system model. Thus, the users can reuse the spectrum more effectively. Simulations show that the proposed method can achieve higher system throughput in the new model than that in the traditional graph model.

Abstract: By exploiting communication temporal and spatial locality represented in actual applications, the paper proposes a locality-route pre-configuration mechanism (i.e. LRPC) on top of the Pseudo-Circuit scheme, to further accelerate network performance. Under the original Pseudo-circuit scheme, LRPC attempts to preconfigure another sharable crossbar connection at each input port within a single router when the pseudo circuit is invalid currently, so as to produce more available sharable route for packets transfer, and hence to enhance the reusability of the sharable route as well as communication performance. Our evaluation results using a cycle-accurate network simulator with traces from Splash-2 Benchmark show 5.4% and 31.6% improvement in overall network performance compared to Pseudo-Circuit and BASE_LR_SPC routers, respectively. Evaluated with synthetic workload traffic, at most 10.91% and 33.72% performance improvement can be achieved by the LRPC router under the Uniform-random, Bit-complement and Transpose traffic as compared to Pseudo-Circuit and BASE_LR_SPC routers.

Abstract: Aiming at the access control problem of the cloud service platform, puts forward the control scheme of multi-level system for multi type coordination.By the definition of cloud services platform multi access control object system,constructs multidimensional Boolean relation matrix. The semantic relation of Boolean matrices, design of large-scale complex network node control system model, and simulate the hierarchical network loop control model.Through the analysis of network model, shows that the research results can better support for cloud services platform in multi-level access, dynamic authorization complexity problems in management control.

Abstract: How to provide dependability based on safety is a challenge faced by train control system. Formal approaches are important for modeling and verification of automatic speed control Systems. In the paper, a formal model of automatic speed control Systems based on Petri nets (ASCS-nets) is presented. And the transformation approaches from automatic train speed control system to ASCS-nets are given. Correctness verification of automatic train speed control system is implemented based on ASCS-nets model.

Abstract: This paper analyzed functions of the network information system based on trusted computing and trusted computing platform based on cloud computing. Raised the propose to expand the application of trusted computing technology to network information system, to meet the needs of cloud computing of trusted computing, trusted cloud computing, implement the trusted cloud computing. In our design, will take the Trusted Computing Platform (TCP) as the basis of cloud computing system, provide some important security functions to ensure the communication and data security.Finally put forward the implement methods.

Abstract: In this paper, we proposed a method for mining mobile users’ Quality of Experience (OoE) model based on weighted LDA. In the recent years, QoE has become an important concept for the quality of networks and services. At present , QoE has attracted the interest of network operators and service providers, because of providing a good QoE service to their customers can satisfy the customers and bring more users. In this paper, we are trying to build up users’ QoE model through topic model, an approach to generate a generative model for data mining. Latent Dirichlet Allocation (LDA) is a feasible and effective algorithm in text modeling. We propose an weighted LDA-based interest model within the modeling framework, and evaluate it on a mobile network users’ behavior extraction system. In this system, we can analyze the users’ behaviors, and build up a vector model for each user through a simple way. Besides, with the help of the topic model, we can get an exact model for users’ QoE, because we can generate the topic model through the vector model. Thus we can get the users’ QoE model, through which we can learn each user’s experience. Then the network operators can provide a better network service for their customers. In the end, we elaborate QoE management requirements for mobile network scenarios, and provide a QoE modeling approach for the mobile network scenarios.

Abstract: Related researches on the influence of microblogging users are only given users’ influence ranking, while cannot determine the problem that which user plays a guiding role in the dissemination of information in the microblogging network. This paper proposed a microblogging opinion leader recognition algorithm called LeadersRank based on personalized PageRank algorithm. On the basis of LeadersRank algorithm research, since the problem of that current microblogging information has been massive data, using the idea of MapReduce programming model to improve the LeadersRank algorithm, so that designed a LeadersRank distributed parallel algorithm based on MapReduce algorithm running in the cloud platform hadoop environment. Finally, experiments verified the effectiveness of the two methods, and made analysis of experimental results.

Abstract: This paper focuses on the access control management of cloud storage system based on NSSC in mobile network. NSSC (Network Security Service Center) is a new key service mechanism, which is responsible for network security service in mobile network management. Through experimental data comparative analysis, it proved high effectiveness and practicality of the NSSC in cloud storage system for access control management in mobile network.

Abstract: Nowadays, with continuous progress in Ad hoc technology, Ad hoc network is no longer limited to some specific areas, furthermore is integrated with mobile communication to expand application scope. Three key factors affecting the quality of routing is enumerated and analyzed in detail in this paper. Among previous research on the integration of Ad hoc networks and mobile communication system, most of them are based on a single factor analysis, not comprehensive analysis. So aiming at this disadvantage, a novel concept, namely optimal routing function, is suggested on the basis of comprehensive consideration of three key factors.