Applied Mechanics and Materials Vols. 241-244

Abstract: It is very necessary to apply motion detection to video surveillance in order to enhance the performance of system. A new design scheme of video motion detect system based on System On a Programmable Chip is proposed. Two cameras will capture the video data in real-time, and transmitted to DE2_70 development board. After the system which is on a programmable chip based on FPGA processing, the cameras survey whether an illegal personnel is in the range of cameras. The system achieves that two-way video to switch through the switch button. The experimental results show that the SOPC realization of the system design improves the processing speed, and the system also has good flexibility.

Abstract: Using HF-Doppler detector we have been observed ionosphere disturbance continuously for about 20 years. Firstly, We gave a theoretic explanation to normal frequency-shift records, then using two typical cases we pointed out that in china there exist F2 layer infrasonic disturbance which due to severe weather. Through analyzing their spectrums, we found three remarkable peaks. And comparing with foreign researchers, we indicated that infrasonic disturbances possess local features. Finally, we concluded local features of infrasonic disturbances occurring in our area.

Abstract: A Wireless Broadband Communication System has been made up based on OFDMA and AMC technologies. The system structure and working pattern is introduced, the OFDMA allocation model, the MIMO and AMC scheme are present, and the parameter such as transmitting power, receiver sensitivity, transmitting antenna gain and receiving antenna gain are designed. The system enables high quality wireless broadband communication. As a supplement with wired communication systems, the system could fulfill the requirement of recovery local communication rapidly when some accidents take place.

Abstract: Traditional distance learning is based on wire network, such as internet, cable television network, telephone network and so on. With the development of wireless mobile network, there are many advantages such as without time and space limit, so it can bring some chance for distance learning video living and video on demand. In the text, we discussed distance learning history and development, wireless network development, and the designing video living and video on demand based on wireless mobile network, at last, the conclusion was given. The terminal users can get distance learning video living and video on demand service through the wireless network.

Abstract: Based on the traditional DSR Protocols have obvious drawbacks such as low packet delivery rate and high routing overhead in the signal intensive UAV network. This paper introduces an improved DSR protocol（Restrict-DSR）. The new DSR protocol can save the space of node routing memory and reduce the routing overhead by limiting the maximum hop count of route request. Simulation results by NS2 show that the RE-DSR has improved the packet delivery ratio and decreased the average of packet end-to-end delay and routing overhead comparing with the conventional DSR Protocols in the signal intensive UAV network.

Abstract: With the development of electronic commerce, the anonymity of the user on the consumption demand is increasingly outstanding. Electronic cash as a result of this demand arises. In an open network environment, how to protect the integrity, authenticity and integrity of electronic cash transaction has become the focus of current research. This paper mainly discusses electronic cash system based on blind signature. Using RSA blind signature guarantees the system's anonymity. It also analysis the system’s safety, and gives the solution method.

Abstract: Uniform circular antenna array of warship can bring beam and interference null steering from 360° symmetry without rotating. Directional communications can be achieved by UCA geometry. To solve the problem that warship’s stance is changed dynamically in course of sailing, a method was suggested that the electricity phases of UCA elements were changed based on information of stance about longitudinal sway, transverse sway and course. The proposed method can change beam directivity, and ensure providing a very directive pattern with stabilization, so that warships communication in moving each other. An expression of array maximum directivity forming with dynamic is proposed for UCA antenna. The simulation demonstrates that the beam forming method of communications in moving is validity, and is worth using with wide application.

Abstract: VLAN technology refers to the virtual local area network technology, which is classifyd into several network segments in logic through the internal devices of existing LAN, rather than physical location, so as to realize a computer network technology of virtual working group. This paper analyzes and studies on the generation, characteristics, and communication method of VLAN technology, as well as its actual application and setting.

Abstract: This paper introduces basic characteristics of UNISCOPY protocol, analyses information to transfer question between a master station and a slave station and the precise location of information displayed on the screen. Exploring questions of main station information level 4, terminal information, information segmentation, synchronized transmission, check parity and screen addressing.

Abstract: This paper brought forward the layered protection of defense-in-depth on the basis of analyzing information classified protection core strategy and large corporations’ net structure 、management and security actuality. Different information systems in different domains are protected according to their security classes. At the same time, the relationship between the domains and their boundaries should be defined, and the protection of domains inside and boundary are implemented. The protection layers are gradually deployed breadth wise, the protection strength are increased lengthways. Finally the objective of defense-in-depth is reached, the protection capability of enterprise’s information system is enhanced.