Applied Mechanics and Materials Vols. 29-32

Abstract: The EEG signal is one of mini-voltage. In order to improve the performance of EEG and increase the measure efficiency, we must eliminate the noise in EEG. Wavelet threshold de-nosing techniques provide a new way to reduce noise in EEG. This paper proposes a wavelet new threshold de-noising function based on the study of the disadvantages of the hard threshold function and the soft threshold function. The simulation results show that the wavelet new threshold function is able to eliminate the noise effectively which can not only save the smooth effect of the soft threshold function but save the numerical value advantage of the hard threshold function.

Abstract: Sleep is the important phenomenon in human’s life. About third time of human is spent on sleeping in which many important physical course happen and develop so that the research of sleep EEG gets more and more regards. The beginning of sleep research often starts from right partition by stages. Different sleep stages correspond with different brain states so that the sleep partition by stages has important meaning for the research of the sleep EEG. In this paper, a method is given for sleep segmentation using Lempel-Ziv complexity. From the result of the simulation, it can be drawn that the complexity measure can helpful distinguish the sleep stages so it plays an active role to find a reliable guideline for the automatic partition of sleep stages in sleeping periods in time.

Abstract: This paper has proposed a concept of Group Control Object, taking an example according to experimental data of elevator group control object of a building; we apply fuzzy logic and neural network to recognize the pattern of the group control object. With the aid of the fuzzy neural network, this task designs to identify the different passenger flow, and classify it into the six models such as the up-peak service model, down-peak service, two way traffic model, four way traffic model, the balanced bi-story traffic model and free duty traffic model. Then it constructs five-level fuzzy neural networks to apply the classification to the elevator group control, and perform the best group control strategy for each model.

Abstract: In traditional gatekeeper architectures, call routing has many drawbacks such as long call setup delay, heavy burden on gatekeeper, low channel utilization and lack of scalability. We propose a scalable routing architecture for next generation gatekeeper, which is independent of real-time services plane. The design principle is gatekeeper call routing may be separated from its call process. Next generation multimedia networks, which feature with large capability and multi-domains, consist of Connecting Domain for call routing and Service Domain for call process. Next generation gatekeeper is the important entity in Connecting Domain, adopts Telephony Routing over IP to realize dynamic routing. We consider this routing as a special type of service and investigate the method of routing creation and routing provisioning. Validation in a testing platform shows that the proposed routing architecture can provide admirable routing performance. It also goes through stress and capability test. So it is a better choice for multimedia communication system with flexible extension and network cost saving.

Abstract: The periodicity and the trend which are the important properties of water resources become more and more variable and complex because of the influence of topography, vegetation and the human activities. Wavelet Analysis which has Multi-resolution Analysis function can provide more detail information of the nonlinear and complex system. The periodicity and the trend of precipitation in different plain regions of Handan are illuminated with Morlet Wavelet Transform in Multi-time scales in this study. It is illustrated that the same periods (5years and 9years) exist in the precipitation in different plain regions of Handan and there are the similar variety and the similar trend in the scale of 5years or 9years in different areas. This study would provide technical support for the integrated management and utilization of water resources of the local region.

Abstract: Experiment is a more direct and reliable way, through which the observation and data analysis can summarize specific qualitative and quantitative relationships and the fire mechanism and laws phenomenon. It can provide a reliable basis for the proposed theory or computational model from the general principle and validation for the theory or the results. Through experiment, heating process takes greatest impact on the heating surface but least on inner parts. While the temperature is ascent to some degree, the heating surface temperature will exceed the temperature and continue to be ascent, which indicates that the coal begins to oxide. While the airflow is increased, the temperature will be slightly increased. The temperature is descent more slightly in the coal temperature because of thermal radiation.

Abstract: A physical model on the volatilization combustion of coal field fire area was established based on its characteristics. The quality exchange equation, momentum equation, diffusion equation and energy equation with the thermal and quality exchange, with the chemical reaction and multi¬-composition flow was analyzed by analytic geometry method. The parameters of volatilization combustion speed, the content of the volatile component and the flame temperature was gained at relatively still high temperature environment. According to the result, the flame temperature of the volatilization combustion of coal field fire area is the heat insulation temperature calculated based on the low-heat value of the volatile component. In the actual fire area, because of the free or forced convection, the true temperature would be lower than in the calculation. The numerical simulation reveals the airflow distribution of static pressure of coal outcrop. The difference between static pressure and dynamic wind pressure changed with a high degree of change is proposed. The variation of gas transfusion direction and velocity in the coal outcrops and the transfusion depth between static and airflow is analyzed near the coal outcrop.

Abstract: The train fire has been greatly focused by fire researchers all over the world, the key to which is the study of smoke flow. The simulation model is set up to analyze the concentration and the temperature of smoke flow during the train carriage fire. The concentration and temperature is very high near the fire in the closed space. Meanwhile, the spreading speed of smoke flow will be accelerated when the doors are open. The concentration of smoke near the fire will be decreased. The simulation shows that the fire should be extinguished at the initial stage. After being developed because of the pouring of fresh air, the smoke concentration and the temporary ventilation should be controlled.

Abstract: As the existence of the many unwanted factors, such as radial distortion and decentering distortion, the model of camera imaging is actually a nonlinear one. In order to successfully realize this kind of nonlinear mapping relationship between the 3D object points and their corresponding 2D image points, neural networks were and are still used. This paper introduced the history of camera calibration with neural network, covered the three types of neural network algorithms that have been used in camera calibration and explained their advantages as well as drawbacks with experiment results. After that, two issues that should be noted before and after the use of neural network were discussed and finally, the concluding remarks were gained.

Abstract: Train control system is a safety-critical system, which requires a thorough safety testing before they are deployed. But the traditional technology of test automation is not sound for safety test of safety-critical software system because of its just aiming at the system functional requirements. Focusing on the safety requirements, this paper addresses a new method to perform safety test of safety-critical system based on safety requirement by using model-based test. The method presents safety automata to express safety properties in term of safety requirements and extract safety model from the safety requirements. It also provides a new technique for automatic generation of safety test case suite. By using the method, we have designed an automatic testing framework and developed an automatic testing platform, which has been applied to standard testing the product of train control system in term of the requirements of Ministry of railways in china, and implement effectively the functional and safety test of the product of train control system in china.