Applied Mechanics and Materials Vols. 446-447

Abstract: The correlation techniques of nodes cooperative transmission strategy in wireless sensor networks with virtual MIMO are presented. A communication model between clusters is proposed. From it, we can see the correlation techniques include coding, forwarding, combining and decoding. The coding is generally divided into three categories: Layered Space-Time Coding, Space-Time Trellis Coding and Space-Time Block Coding. Forwarding can be broken down into Amplifying Forwarding, Decode Forwarding, and Selecting Dynamic Relay. Select combining, equal gain combining and maximum ratio combining are the common combine methods. The decode method is maximum likelihood algorithm.

Abstract: Frame-relay and OSPF is a common application combination in engineering practice, A lot of problems need to be paid attention to when using different OSPF network type in different Frame-relay topology environment. Misconfiguration is more likely to cause network to run abnormally. According to the engineering practice of Frame-relay and OSPF, this paper puts forward the key problems in Frame-relay multipoint interface network running OSPF, and makes an intensive study of the main points of solving problems.

Abstract: The technology of CT scanning and 3D reconstruction were used to construct 3D model of realistic human upper respiratory tract, and the method of large eddy simulation was used to simulate the process of vortex evolution in the model subtly. The results show that, several vortex tubes with low vortex intensity are formed in the rear of mouth; transition occurred in the pharynx, and the vortex structures break up rapidly; fully developed turbulence appeared in trachea, and several vortexes the shapes of which are similar to the wall of trachea appeared on the anterior wall of trachea; the large-scale vortex breaks up the small-scale vortex structures gradually in the bronchi.

Abstract: The interactions between attackers and network administrator are modeled as a non-zero-sum dynamic game with incomplete information. Strategies taken by offenders and defenders are dynamic game processes which are mutually dependable and constantly repeated. This paper uses game theory to analyze the model and process of offense and defense counterwork, and suggests that information security problems can be studied from game theory's point of view.

Abstract: Scalable Vector Graphics (SVG) and Common Information Model (CIM) are the graphics and module information sharing and format specification standard of power automation systems. The CIM/SVG graphics/module power platform integration technology is one of the key topics of graphics and data sharing and visualizing between various power application systems. Two main developing technologies, the underlying developing approach with programming language and the Visio based secondary development, are compared from aspects of primitives modeling, graphics system developing and topology analyzing. Cases study shows the merits and drawbacks of each approach.

Abstract: The information island problem of interacting between graphic and module data of various power dispatching automation application systems can be solved by using the CIM (Common Information Model) to demonstrate the data of the equipment and SVG (Scalable Vector Graphics) to show the equipment. A visual intelligent calculating and analyzing CIM/SVG graphics-module integration power platform is proposed based on Microsoft Office Visio 2007 and secondary development of Visio Studio C#. The presented platform combined the powerful drawing function of Visio with IEC (International Electro technical Commission) 61970 standard and case study shows its feasibility and effectiveness.

Abstract: In recent years, the coverage of terrestrial mobile communication network is more and more extensive, and the mobile phones have occupied the vast majority of voice communications in almost all countries. However, satellite voice communication system is still playing an irreplaceable role on the vast sea and the land area which are not covered by the land mobile communication network. The motion characteristics of the SIGSO satellites and its new demands and characteristics to the system are analyzed, and a novel very low rate satellite telephone system is put forward. The speech coding algorithms are studied, and a suitable speech coding algorithm and coding rate of 600bps is selected for the SIGSO satellite communication system. The overall design of the satellite voice communication network is given, including link budgets, network structure, system components, system signaling and so on. This satellite telephone system can get access to the PSTN network through ground gateway to achieve interoperability with the public network.

Abstract: Maintenance tools present a difficult problem in complex support system, for the considerable varieties to be integrated and optimized. In order to obtain the solution, a maintenance tools category integration method was developed, which minimizes the support burden and costs. A maintenance tools category integration analysis method was employed based on case analysis method, which can classify the maintenance tools scientifically by its main characters. The integration flow and implement steps were employed, which can improve the solving efficiency for the integration method. At last, a numerical example was given, which examined the feasibility and validity of this method.

Abstract: The recently developed nearest-nodes finite element method (NN-FEM) has a number of advantages over the conventional finite element method (FEM). The most attractive one is that its performance is nearly not affected by element distortion. However, low computational efficiency of NN-FEM is a major concern, as in the original NN-FEM a local problem has to be solved at each quadrature point to construct shape functions there. In this paper, a new strategy is introduced in NN-FEM for constructing shape functions aiming at improving its computational efficiency. The strategy is, for regular-shape elements, shape functions are constructed at the element center and the obtained shape functions are used at all quadrature points in the element; only for severely distorted elements, shape functions are constructed separately at each quadrature point. Numerical results show that computational efficiency of the NN-FEM can be significantly improved with the above strategy, while other performance of the method is not affected.