Advanced Materials Research Vols. 219-220

Abstract: Based on investigation into available monitoring and control system technology at home and abroad, this paper presents extensive surveys and thorough analysis of the safety supervision system being employed in Chinese coal mines. Taking a mine area as example and according to years of working experience in technical management of coal mines, the author combines the status quo of the mine area and existing problems in the supervision system for production safety in Chinese coal mines, and provides a design proposal of supervision system for production safety in coal mines, where a digitalized supervision system for production safety in coal mines serving dual-function of supervising production safety and commanding accident rescue is designed.

Abstract: Magnetic Resonance images are often corrupted by Gaussian noise which highly affects the quality of MR images. In this paper, a Non-Parametric hierarchical Bayesian image sparse representation method is proposed to wipe out Gaussian distribution noise coupling in MR images. In this method a spike-slab prior is imposed on sparse coefficients, and a redundant dictionary is learned from the corrupted image. Experimental results show that the method not only improves the effect of MRI denoising, but also can obtain good estimation of the noise variance. Compared to non-local filter method, this model shows better visual quality as well as higher PSNR.

Abstract: By taking transmission delay into account, the optimization of distributed rendering environment (DRE) was concerned in this paper. Considering distributed animation rendering environment as the object of study, two Generalized Stochastic Petri Nets (GSPN) models for “completely distributed storage” infrastructure (CDSI) and “hybrid distributed storage” one (HDSI) were constructed respectively. Moreover, by choosing average time delay as the performance index, analysis was conducted by applying the equivalent formulas for solving Stochastic Petri Nets (SPN) models of serial and parallel types to these two GSPN models. Based on comparison of such models’ numerical simulation results, conclusion on these two infrastructures’ advantages and disadvantages is deprived thereby. It offers important quantitative foundations for choosing appropriate storage schemes and scheduling algorithms.

Abstract: An important breakthrough in Object-Oriented area is to raise the conception of design pattern, which was not born long before, but soon becomes a bright star due to its particular advantage in the design and development. In this paper, we analyze the support of UML to design pattern, and accomplish the modeling method based on the role design pattern. Under the direction of design pattern, to bring the design pattern into the development of practical training system, which interprets the development process of the software in both theory and practice.

Abstract: Along with the development of power electronic technology, various inverters are widely used in all sectors. the advanced modern control theory and methods have been applied in the inverter, which made the stability and reliability for the inverter have improved greatly. In this paper analyses the working principle for SPWM inverter that used voltage and current cut-loop PID control strategy, in the voltage loop and current loop make use of its transfer function to both no-load and full load conditions for digital simulation, and get different Bode diagrams, meanwhile also analyses the different simulation results for system that without add PID controller and join PID controller, with the analyze results can determine the open-loop frequency characteristics of various parameters for the closed- loop system, and to ensure the output inverter to achieve the intended targets.

Abstract: To damp the inter-area low-frequency oscillation in power systems, a wide-area damping supplementary inter-area controller, based on output prediction observer and LMI method, was designed in this paper. Simulation results of a test system show that the wide-area damping controller can well damp inter-area low-frequency oscillation, and is insensitive to time-delay to some degree.

Abstract: Rutting is a common and serious phenomenon in asphalt pavement especially in high temperature areas. Phase change material (PCM) can adjust temperature through storing and releasing thermal energy during phase change process and has been used in thermal energy storage areas and building materials. However, the use of PCM to regulate the temperature of asphalt pavement has not been widely studied. In this paper, the feasibility of temperature self-control asphalt pavement using PCM was studied for preventing rutting. The temperature-control mechanism of asphalt pavement with PCM has been presented. The selection criteria of PCM used in asphalt pavement have been made. Meanwhile, a paraffin/expanded graphite shape-stabled phase change material with a phase change temperature range of 40°C~50°C has been used in this study. The temperature rising test of asphalt concrete showed that sample with PCM exhibited a lower temperature than the control sample, which indicates that it is feasible to use PCM in asphalt pavement for lowering temperature and preventing rutting.

Abstract: To estimate the number of mechanical vibration sources from the convolution mixtures with fewer sensors than sources, a new method combined with EMD-SVD- DE（Empirical Mode Decomposition, EMD; Singular Value Decomposition,　SVD; Dominant Eigenvalue, DE）was proposed. The characteristic forms of vibration sources were obtained through the EMD of the mixtures. The relation matrix of the characteristic forms of different mixtures was used to get the eigenvalues of sources which were used to determine the number of sources by means of SVD and DE. It is verified that the new method yields a correct estimate of source number in the simulation and test. It is help to analyze the mechanical vibrations in the fault monitoring system and to separate the useful mechanical vibrations efficiently from the mixtures.

Abstract: Grid task scheduling is an NP problem , performance of scheduling algorithms greatly influences scheduling results. Aiming at the shortages of the existing Evolutionary Algorithm, such as premature convergence, search process easily falling into local optimum, poor scheduling results and so on, this paper proposed an improved immune Evolutionary Algorithm which introduced concentration mechanism in the immune system into Immune Evolutionary Algorithm and adjusted regulator to adaptive function. Simulation experiment shows that, convergence speed and performance of the improved algorithm are significantly improved and it can better converge to global optimal solution, applying the algorithm to grid task scheduling can obtain better scheduling results.

Abstract: Applying the 3D design and finite element technology to the design of city bus body, the model analysis of bus body frame was carried out. On the basis of general modeling of bus body, the locus of bus body frame was constructed in light of the inner surface profile of body cover panel. The 3D models of both bus body frame and floor frame were constructed under Pro/E, and the virtual assembly of them was completed. By leading the wire frame model of bus body frame in ANSYS software, its FEA wire frame model was obtained. The natural frequency and vibration mode of bus body frame can be known by means of model analysis. It lays the foundation for the FEA of whole bus body frame.