Applied Mechanics and Materials Vols. 602-605

Abstract: A numerical simulation of TNT explosion on the soil surface is presented in this paper. It demonstrates how the blast wave propagates on the soil surface and interacts with the soil surface. Compared with the explosion in air, a comparative analysis on the distribution of the shock wave overpressure is implemented. The results show that the space on the soil surface close to the explosion source can be divided into a relatively high pressure region and a relatively low pressure region. Moreover, by defining the scaled height H, the interface of two regions comes about H = 0.35.

Abstract: In order to enhance the security of the English character document, data-level information security issues have been researched on the English characters document. Use object-oriented programming to get the character information in English characters document and also get the encoding. Use the “long key stream” algorithm to encrypt. During the process of encryption and decryption, the lossless of English characters file format information is maintained. Also, the setting of encryption and decryption is introduced. English characters document which use this encryption method cannot be cracked illegally. Research on this simulation model guarantees the information safety of English characters document on bottom-level.

Abstract: With the development of computer and network technology, the storage and analysis for complex and large-scale of data can be implemented. According to the requirement, this paper designs a large-scale data management system based on C/S structure which realizes concentration, integration, security management, in-depth analysis and report generation of the field data. Application of the system can improve the scientific management level of enterprises, enhance employee productivity, ensure security, integrity and accuracy of the data, and provide important data for the performance review and decisions of enterprises development, thus improving economic efficiency of enterprises.

Abstract: In order to meet the uncertain data stream mining demand in large dynamic database, a frequent probability item mining algorithm was proposed base on sliding window. The mass data in the database was regarded as a data stream. In the window model of data stream, the frequent item set was extracted according to the probability frequency distribution information of data. Compared to the traditional algorithm, the mining environmental constraints of the certain data stream was overcome, the defect that the relevant information was easy to lose was improved. The true information of data was reflected fully, and the most accurate frequent item was minded. Simulation result shows that the new algorithm can mine the frequent items accurately, and the accuracy rate is higher than the traditional method. It can process the data quickly. It provides effective strategy for analyzing the large database, and it can meet the memory requirement and performance requirement in database analysis and mining.

Abstract: With the application of digital watermarking based on spread spectrum communication technology and the difficult control characteristics of watermark load intensity and invisibility, this paper considers the best compromise between watermark robustness and invisibility factors, and puts forward a digital watermarking algorithm using spread spectrum communication technology. By ultimate strength loading watermark test, the algorithm is verified to have good robustness. Chinese library classification number: TP391 literature identifier: A

Abstract: According to the multilayer sensor network structure of mobile nodes, proposing a coverage optimization control policy based on voronoi division. Based on the mobile policy of Sink nodes by the voronoi division, the essay proposes a coverage optimization control algorithm (COCA) based on coverage hole calculating to optimize the initial random deployment of sensor nodes, and then to eliminate coverage holes and improve the coverage performance of network. Simulation results show that, compared with the random deployed network, the COCA algorithm only requires fewer nodes to achieve a higher coverage ratio and to maintain in low energy consumption, which embodies optimum performance of the network deployment.

Abstract: Distributed file systems such as HDFS are facing the threat of Advanced Persistent Threat, APT. Although security mechanisms such as Kerberos and ACL are implemented in distributed file systems, most of them are not sufficient to solve the threats caused by APT. With the observation into traits of APT, we propose a trusted distributed file system based on HDFS, which guarantees another further security facing APT compared to the current security mechanism.

Abstract: Cloud computing can dynamically allocate the software or hardware resource and information resource in accordance with the needs of different computer users, so as to expand the virtual resources of computer, but data information exists a big security risk in the process of data parallel calculation or the data sharing, so it needs to carry out the risk assessment on the security of signal. In cloud computing, this paper introduces the second-order difference quotient calculation principle in the model of information risk assessment that has accelerated the speed of information risk assessment, and adopts second order linear security authentication model that has strengthened the security of the cloud computing. In order to verify the validity and reliability of the model, this paper uses C program language to design the algorithm and inspects the cloud data with possible existing risk, and then it obtains the deviation curve of numerical calculation and theoretical value, which provides the technical reference for the research of cloud information security technology.

Abstract: The network economy era brings new challenges to all aspects of society, and the construction of network culture industry also brings an urgent request. Due to the complexity of network culture industry, the construction and study of cultural network industry has certain challenging. In order to realize the massive network industrial data analysis, we introduce the genetic algorithm into the network control model, and put forward the distributed network control model based on genetic algorithm, which can realize the massive data analysis. In order to verify the effectiveness of the algorithm, this paper uses MATLAB genetic algorithms toolbox to debug the algorithm, and obtains the genetic algorithm fitness curve and the data transmission quantity statistics. It provides the theory reference for the construction of network culture industry.

Abstract: Social commonweal work is a traditional virtue in China, which is also an important aspect of building a socialist harmonious society. With the continuous development of social economy and the accumulation of personal wealth, the emergence of a number of rich public consciences of organizations and individuals in society has held a wide variety of public activities to do publicity for the protection of animals and environment, etc. Although these activities are the public welfare, without fierce competition, but the exercise load exists. How to guarantee the exercise amount to adapt to different age groups, there is almost no any research. This paper firstly discusses the computer optimization technology. And then it constructs the computer optimization control model of exercise load in public welfare activities. At last, it carries out computer simulation analysis on the model. The results show that the introduction of the optimization model is conducive to control the exercise load in public welfare activities, so as to formulate a reasonable plan of public welfare activities.