Applied Mechanics and Materials Vols. 651-653

Abstract: the (15, 1/6) standard convolution codes of CCSDS is powerful and is often used for satellite communication, and it is also the fundamental of designing channel code for deep space communication. After analyzing the channel encoding and decoding solutions in previous spacecrafts, the performance of CCSDS (15, 1/6) standard convolution codes is researched. The encoding efficiency is get by simulating (15, 1/6) standard convolution codes’ encoding system in C translation environment. The decoding performance and encoding gain are get by simulating (15, 1/6) standard convolution codes’ decoding system in BPSK modulation, AGWN channel and Viterbi decoding scheme.

Abstract: The idea of mathematical modeling is used to establish the quantitative model of information system vulnerability assessment, and the model is solved by using the partial differential method. The algorithm is realized by using VB programming, and it obtains the quantitative solution of information system vulnerability. Quantitative assessment of information system security and risk is the difficulty of system vulnerability assessment, and it establishes the risk model of system by means of mathematics modeling idea. The risk model is divided into the actual risk and the potential risk. The paper uses VB programming software, and establishes a quantitative model of information system evaluation by combining with partial differential method, and the algorithm is carried out the experimental verification by using the method of numerical simulation. Through the calculation, the mathematical modeling ideas can effectively obtain the vulnerability quantitative standard and the risk level of information system, which provides the technical reference for the research of information system security evaluation method.

Abstract: In the teaching training and competition of aerobics, the music exists throughout, and relies on each other; and so introduced the hardware and software environment, the corresponding production steps and methods of operation in aerobics computer music production, thus providing a certain reference to aerobics music production and study.

Abstract: SYN Flood is a typical distributed denial of service attack technology. SYN Flood, which is one of the most popular attack method of DDos, destroys the network by the Loophole occurred when three-way handshake of TCP protocol happens. It describes the principle of SYN Flood attack in the paper, explores defense strategy and implementation method under Windows. These defensive measures can resist the SYN Flood attack rather well, It has good practicability and reference value.

Abstract: By utilizing a variety of switching technologies and embedded systems, this paper introduces the design and implementation of the maintenance training simulator of a comprehensive switch machine from the aspects of its function, system architecture and hardware design.

Abstract: Owing to the technical complexity and high integration, there are problems of high difficulty and high cost of after-sales service personnel training in a certain type of communication controlling machine. A software system of maintenance and simulator trainer is designed and developed. By integrated use of a variety of techniques, the communication transfer function and maintenance and simulation training function of the simulator trainer are achieved in this paper.

Abstract: The mobile terminal is a indispensable communication tool in people's daily life.Mobile applications are widely used in daily office of various industries. But there are many mobile terminal security risks.At present,the security mechanism of mobile terminal is weak,therefore how to ensure the mobile terminal security has become a hot topic of the industry.This paper put forward a solution of mobile terminal security management system which based on digital certificate,Specific praper discusses the design of the whole system,the system architecture,application of digital certificate in this system, background design,front design,and application of system also be described in detail.The design of the mobile terminal security management system has a certain significance.

Abstract: With the development of information technology, people will be faced with a lot of difficult problems that how to implement information sharing between different management information systems. This article not only described about XML and SOAP technology theoretically, but took the example of the management system of university logistics service and warehouse management system. It also analyzed and implemented the principle of shared data communication method between heterogeneous systems.

Abstract: Recall ratio and Precision ratio are two important indices of the effect evaluation of computer information retrieval. This paper analyzed factors impacting Recall ratio and Precision ratio, then discussed the improving of computer information retrieval efficiency from retrieval approach, database selecting and retrieval pattern, etc.

Abstract: With the rapid development of Web technology, provides abundant information for people, at the same time bring a lot of information redundancy. How to quickly locate the user requirements, is currently one of the common problems in the network retrieval, especially in the field of space information. Spatial data mining has caught more and more scholar's attention. With the rapid development of computer network technology, how to carry on the spatial data mining on the Internet or Intranet, namely how to make Web based spatial data mining is a new research field of SDM, is also one of related scholars increasingly focus on research topics. This paper mainly studies and summarizes the application prospect of the technology of spatial data crawl based web.