Applied Mechanics and Materials Vols. 635-637

Abstract: An improved node importance evaluation method is proposed. The importance of nodes are not only determined by its location in the network, but also limited by the contribution of its neighboring nodes. The location of the node is determined by its betweenness. The contribution of the node is impacted by the betweenness and closeness centrality of its neighboring nodes. Experiments show that this proposed method is suitable for satellite communication network applications, and obtains accurate evaluation results.

Abstract: For the varied circumstances in the evaluation of complex power communication systems, this paper proposes a reliable evaluation method based on normal cloud model and fuzzy Petri net. The simulation results show that the model in this paper can effectively evaluate the system reliability when compared with the other models for the same factor.

Abstract: The weak lighning protection performance of transmission lines should be improved in complicate climate and complex topography as well as frequent lightning activities in Sichuan Area. In order to improve stability of power system, it is very important to improve the assessment and rebuilding abilitiy of lightning protection for transmission lines. In this paper, we researched the lightning protection of transmission lines by the technology and strategy of differentiated lightning protection. We analyzed the distribution law of lightning flashovers for tower span, landform, lightning protection measures and so on. The analysis results can provide a macroscopic guidance for differentiated lightning protection work.

Abstract: We study the influence on the luminous efficiency of Si-based LED with different chip spacing. It is found that the optimal chip spacing is 2mm. Furthermore, multi-chips LED with top and back electrodes, according to a certain permutations and combinations way, are packaged integrally on the independent silver reflective layers. We find the LED integrated package devices have higher driving voltage and lower driving current than traditional LED devices with top and back electrodes. In addition, our study shows that independent silver reflective layers can obtain a better luminous efficiency and thermal property.

Abstract: This paper presents a small ARM-based frequency control system, the voltage 220V/50Hz mains, rectified, filtered into DC, then reverse into adjustable frequency alternating current supplied to the motor used. Through software algorithms SPWM control signal generated by the microcontroller, the control signal sent through the intelligent power module, the realization of the DC inverter process. The design is simple, functional and meet the current frequency control system, modular, digital trends, has a waveform, small size, high efficiency, frequency wide range of features. Has good practical value and low cost.

Abstract: High-efficiency control of the motion of the oil film plays a critical role in optimizing electrofluidic display (EFD) technology. In this paper we focus on studying the effect of different pixel shapes on kinetics of electrofluidic. Four different kinds of pixels including square pixel, rectangle pixel, trapezoid pixel, and triangle pixel were designed and discussed. The electro-optic characteristics and the switching dynamics of four electrofluidic pixel arrays were studied respectively. The results indicate that the reduction of the inscribed circle of pixel grid leads to an increase in the threshold voltage. When the geometry of pixels is asymmetric, the oil film prefers to move towards the small angle which can obtain uniform motion of the oil. Moreover, it also affects the speed of the moving oil/water interface to some extent. In all the geometry design of the pixel provides useful directions for improving the electrofluidic display technology.

Abstract: Optimization of the PV array on roof has a great influence on designing of the maximum capacity of PV system. This paper analyses the effect of various factors on the maximum output power of PV array system on roof. Model for optimizing the PV array on the roof have been set up for simulation, and the calculation results show that the number of PV subarray is smaller, and the PV system capacity is larger. And then we can get the general design method for maximum photovoltaic system capacity under given area.

Abstract: According to the characteristics of the message middleware and JMS specification, this paper introduces several methods to improve the performance of the security of the JMS message middleware. The basic idea is to use two-way digital signature authentication information, and in the process of message transmission, to use negotiated session key and asymmetric encryption technology to encrypt messages. Using this mechanism can effectively protect the safety of the message transmission and storage, and to achieve a smaller time overhead associated with acceptable performance.

Abstract: An universal testing platform for equipment-embedded software is designed and realized to support the dynamic verification test of embedded software on CI level and system level. This Platform, based on LAN and USB bus architecture, has provided the function of system interface modelling, test project management, test case script code, test result control and analysis, and test report generation, and is available for real time, closed-loop and non-invasive dynamic testing on the embedded software with the characteristic of portability, easy operation, flexibility in size configuration and universality of protocol description.

Abstract: A high performance and high voltage half-bridge novel IGBT driver circuit is described in this paper. The module integrates dual insulated driving and special protection circuits. It has high push-pull driving capability, bootstrap power supply technology and is easy for inverter miniature design. The paper also introduces the application in portable diesel engine generator and discusses some attention items in practical application. Experimental results show that this driving module has better performance and can reliably drive and protect IGBT.