Applied Mechanics and Materials Vol. 707

Abstract: The analysis of road vehicle collision accidents reconstruction is a hot automotive passive safety subject. When reconstruct the vehicle collision accidents , start from the final position of the vehicle, and build the back projections by using the kinematic and dynamic models, according to the relevant theory, experimental data. namely: the after collision stage - Collision stage - pre-crash phase to reproduce the actual situation of the entire accident process in time and space. Thus the technical state of vehicle accidents before the collision can be known, and the causes of the accidents can be further analyzed. In this paper, some aspects related to rigid body kinematics and rigid body dynamics will be studied.

Abstract: In the process of working, storage, finished fodder acceptance and the preservation process of grass materials, the moisture content of forage is a very important indicator. The blast oven drying method has been generally adopted in the measurement of moisture content. The related experiment showed that the microwave oven method for grass moisture content measuring improved 200-400 times in the efficiency compared with blast oven drying method. The microwave oven method was accurate and easy operating. So, we can conclude that microwave oven method is a viable method for measuring the moisture content.

Abstract: The phase noise performance of frequency source has a direct impact on the target measurement such as the adjacent channel interference of the electronic system, the transmission quality of information, the resolution of radar. In this paper, we achieved an X-band high stability, low phase noise frequency source which based on the DDS combination with frequency doubling technology. The test result shows that when the output of the frequency source is at 8.544GHz, the phase nosie is-103.58dBc/Hz at 1kHz and-101.94dBc/Hz at 10kHz.

Abstract: Emergency communication refers to the appearance of natural or man-made sudden emergencies, which comprehensively use various communication resources to guarantee the emergency rescue and necessary communication. Emergency communication system requires not only mobile, but also rapid response and wide range. According to these requirements, the paper establishes a process model based on Object-oriented Petri net. The application shows that the model can be used to conveniently describe the dynamic and uncertainty characteristics of emergency communication tasks, which can reduce the complexity of process organization and provide the conditions for fast restructuring and integrating functions of module tasks.

Abstract: In wireless sensor network, there are several links from one node to another, selecting the high quality link from the links is an important basic research. As a general algorithm, the typical link selection algorithm is usually used in selecting the high quality link, but the typical link selection algorithm needs lots of data packages as the testing samples. But the energy of a wireless sensor network is limited; therefore, the typical link selection algorithm is not suitable for wireless sensor network. The paper puts forward two new Bayesian link selection algorithms. Simulation results showed that the news algorithms have better performance than typical link selection algorithm in the case of small samples.

Abstract: Compared with the traditional information retrieval, knowledge retrieval based on ontology has higher retrieval efficiency. In order to adequate arena for the effectiveness of knowledge,and intelligence to meet the users on the implicit and explicit knowledge retrieval demand, the author designed a system model of intelligent science based on ontology. Detailed analysis and elaboration of the three aspects: subject knowledge ontology construction, ontology knowledge retrieval, service based on intelligent. Provide methodological guidance and technical support to enrich the research contents in the field of knowledge retrieval.

Abstract: With the increasing popularity of network technology and communication technology, networks are gradually penetrated into the field of education, breaking the time, space and geographical constraints, to achieve a high degree of sharing of teaching resources. Information instructional design rooted in the practical application of instructional design. In the course of postgraduate training, to encourage teachers to apply information technology instructional design, not only to meet the needs of graduate professional knowledge content independent learning and collaborative learning, but also to give students a useful design tool, to deepen the understanding of teaching content. Finding and solving problems in the process of gradually develop their practical ability to innovate.

Abstract: Gymnastics to gain success in colleges and universities must have one of the most basic ability which is teaching ability. To the teaching ability, the evaluation is objective and correct, so that the students can get all-round development during undergraduate course, and to be able to meet the needs of the society is the difficult problem in teaching. This study adopts multi-level fuzzy evaluation method, establishes teaching ability index system and evaluation method, and hopes to provide certain theoretical basis for track and field teaching in the future.

Abstract: The main purpose of computer network security research is extract system data and factors related to the computer network security, and then establish a model which is analyze the security of computer network. Analyze the association rules and its related mining algorithm Apriori, through the application of the improved Apriori algorithm founded on pretreatment in computer network security teaching; explain the process of data mining and analysis of mining results, finally points out the future research direction. This model mainly analyzes the contents of three aspects as the requirements of computer network system security, degree of safety and threats to computer security, to check the security of the computer performance.

Abstract: Internet technology as the cutting-edge of the current information technology, it has penetrated into every aspect of human life, more and more government agencies, enterprises are using Internet to improve their office efficiency and to establish new business operation model, in order to improve its reaction ability in fierce competition. Internet has brought convenience for people to work, while the security problem of network also will follow. The internal network not only needs to ensure the security of their data, but also needs to exchange data with the external network, then by adopting network security isolation system which takes gatekeeper technology as its core technology, so that we can ensure that internal network and external network will have physical isolation at any time, meanwhile, according to business needs, it also has multiple forms of information and data’s exchanges.