Advanced Materials Research Vols. 219-220

Abstract: As a nonlinear dynamic system, the permanent magnet synchronous motor (PMSM) can exhibit prominent chaotic characteristics under some choices of system parameters. The existence of chaotic attractor of the PMSM is verified through the centre manifold theory and Poincaré section. Chaotic phenomenon affects the normal operation of motor. In this paper, it makes the PMSM in a stable state to control chaos of the PMSM with a control strategy of delay feedback, which can eliminate chaos well.

Abstract: Based on the measured and denoised vehicle engine noises, the sound quality evaluation (SQE) techniques in common use for A-weighting sound pressure level (SPL) and psychoacoustical parameters, such as loudness, sharpness and roughness, are performed and compared in this paper. The wavelet threshold shrinkage method is adopted for sound signal denoising. The comparisons suggest that the A-weighting SPL is not sufficient and can only be used as a reference in vehicle SQE, the psychoacoustical parameters can provide a complete description and more exactly reflect to the subjective feeling of vehicle noises, should be considered in vehicle designs.

Abstract: In this paper, we combine the web mining and fuzzy clustering and give the concept of web fuzzy clustering processing model and its application. We also introduce the web fuzzy direct clustering method in brief. Web fuzzy clustering can be used in the web user clustering and web page clustering of web usage mining.

Abstract: This paper selected some listed companies of the manufacturing and information technology industry that have achieved full circulation by the end of 2008 and used factor analysis to study the impact on performance after the split share structure reform. By comparing horizontally and vertically, it came to the split share structure reform does improve corporate performance of listed companies in China; and then it analyzed the performance of listed companies on public life and economic area.

Abstract: The data backup and disaster recovery of computer network is an important security technology. Aiming at current network, enterprises and information system data are easier to infecting virus suffering hacker and losing data because of negligence. This article explores the computer network data backup and the feasibility of schemes in disaster recovery technical to ensure that the enterprise information systems should be safe and meet the necessary data backup.

Abstract: The paper gives the linear discriminant function (LDF) based on the theory of linear discriminant analysis (LDA) combined with computing weights of the different indicators by analytic hierarchy process (AHP) to predict a new e-commerce customer’s individual credibility level and analyzes the result of a simulation test to justify the theory in this research.

Abstract: It is significance to identify and track convective clouds using satellite images in nowcasting and severe weather warning. This article applies simulated annealing algorithm to match and track convection clouds identified from infrared channel images of FY-2C satellite. The preliminary results suggest that simulated annealing algorithm is simple and effective to gain satisfactory results with adjustable features. The results also show the feasibility and characteristics of simulated annealing algorithm in cloud tracking and provide reference of simulated annealing algorithm application in other related research areas.

Abstract: With the detonation of information, the requirement of real-time data collection has been paid increased attention. It is more difficult that a real-time information system in practical application not only considering its convenience of maintenance, credibility of performance and flexibility of configuration, but reducing its developing cost as well. Therefore, to borrow the idea from the layered design for software system, a virtual layered concept was presented in this paper. And also a virtual layered design scheme for real-time information system based on the concepts of virtual layer and layered design was built to provide a flexible configuration method for development of series systems in different applications. The practices show that this scheme has strong flexibility, good efficiency and integrated optimization.

Abstract: In this paper, we shall research on a class of thermo-viscous-elastic anisotropic dissipative material system equation. The analysis semi-group theory and two-dimensional singular integral operator identical relations are used in this paper; the equations denoted by some singular integral operator equalities are studied in two-dimensional round field. We shall push out the properties of the equations, the necessary and sufficient conditions of solvability. Furthermore, the formulas of their exponent operation are pushed out too.

Abstract: Course evaluation is necessary means to ensure the improvement of course construction level. A new course evaluation model is proposed based on the fractional order systems in this paper. An algorithm for linear fractional order systems founded on Grunwald–Letnikov’s fractional calculus definition is described. The fractional evaluation model is composed of fractional order and common coefficient. Model parameters can be determined by a large number of data and mathematical statistics method. The proposed model was applied to actual course evaluation work of Capital Normal University Information Engineering College. The practicability and effectiveness of the method have been validated.