Applied Mechanics and Materials Vols. 155-156

Abstract: High-tension power delivery based on electromagnetic coupling for hot spot temperature in power equipment and the systems of current on-line monitoring of early warning is an effective way to solve the 'energy island' .In this paper, a miniature, low cost, high reliability, easy installation and maintenance communication power supply that based on electromagnetic coupling has been designed, it also can provide a lasting and stable power output. Since the central position of the receiver coil and the rectifier filter circuit in the power supply，Optimization design and simulation have been made for the coil and the rectifier filter circuit. A three-dimensional coil was used as the receiving coil, optimization results show that load power is 10.18w at the conditions of low-frequency and high-voltage. It achieves the objective of the miniature and low-cost. The simulation results of rectifier and regulator show that the system can transfer energy at the range of approximately 2% fluctuation.

Abstract: As it is difficult to measure the temperature accurately under actually environment, this paper develops a virtual temperature measurement system based on LabVIEW. The system consists of AD590 temperature sensor and virtual instrument, and the properties and structure of AD590 is discussed in this paper. In addition, we do some research on the measurement method, and use soft filter and Normalized method to remove noise and improve the measurement accuracy. The structure and soft system of the virtual instruments system are designed and a high value measurement system is achieved using the resources of the virtual instruments. The experimental results have shown that the system can satisfy the accurate requirement in harsh condition.

Abstract: The harmonic problem of power grid is very serious in many countries. The use of a nonlinear load makes electric energy quality of transmission and transformation system worse. Active power filter, as harmonic wave of power system, has developed rapidly in recent years. This article has make analysis on influence and damage of present power system harmonic & reactive power on power system; stated the basic theory of detection approach which is based on instantaneous reactive power and harmonic dynamic; analyzed harmonic detection improvement methods based on instantaneous reactive power.

Abstract: A finite-difference numerical model is used to study the influence of surface textures configuration and depth on lubrication performance of hydrodynamic journal bearing. Reynolds equation is adopted to calculate the bearing dimensionless load carrying capacity, friction force and friction coefficient under different eccentricity ratio, textures configuration and depth. Results show that partial texturing in the inlet zone with shallow dimples and in the cavitation zone with deep dimples could improve bearing performance appreciably. The effect of the textures on bearing tribological performance was influenced by the eccentricity ratio. The advantage of partial textures decreases when the eccentricity ratio increases.

Abstract: Suitable structure for plenum chamber lead to a significant enhancement of the relaxation heat setting machine performance, this paper presents the influence of opening ratio and static pressure on flow velocity. Optimization design method is employed to identify the optimum opening ratio and structure dimension of plenum chamber quantitatively. Furthermore, a numerical approach is presented to validate the optimization results, numerical studies indicate that decreasing opening ratio has better effect on mending air flow uniformity than constant opening ratio, the optimized structure results in the relative velocity error rate decrease by 23.7%.

Abstract: It put forward questions for the calculation equation transmission efficiency of CHT-100 type Circulating power of the efficiency transmission gear experiment set. Put forward new mechanics analysis method. And according to the new mechanics analysis method, the analysising and demonstrating aim at the calculation equation of transmission efficiency of CHT-100 type Circulating power of the efficiency transmission gear experiment set. it gives the new concept of equation of gear transmission efficiency.

Abstract: As the fractional Fourier transform has advantages in signal processing areas, it has been used more and more in various fields. Based on audio data sources, the paper analyzed the rotation factor sensitivity and diffusion of fractional Fourier transform. System test results show that the fractional Fourier transforms rotation factor sensitivity Δα≥10-3. It plays an important role in the area of attacking chaos. Diffusion analysis shows that it will lead to the complete failure of inverse transform to restore the original signal, when any element cn of fractional Fourier domain changes 0.2 times plus or minus greater than the original data.

Abstract: In order to solve the density based outlier detection problem with low accuracy and high computation, a variance of distance and density (VDD) measure is proposed in this paper. And the k-means clustering and score based VDD (KSVDD) approach proposed can efficiently detect outliers with high performance. For illustration, two real-world datasets are utilized to show the feasibility of the approach. Empirical results show that KSVDD has a good detection precision.

Abstract: The random reliability analysis model for wear was established based on random process theory and wear research. The wear experiment scheme on load, sliding speed, surface hardness and bearing capacity of lubrication was instituted by the uniform design method, and carried out on a vertical universal friction/wear tester. The static wear predication model was established by the partial least squares based on test data. It is found that the wear extent obey to normal distribution by checkout of the probability paper and mathematic expectation function fitting and residuals distribution, the variance function fitting and residuals distribution based on the test data of random process. The reliability of definite working life was gained by calculating with established reliability model, and compared with test data, the analysis method is a valid method for wear reliability.

Abstract: LogicSQL is an object relational database management system implemented with the advanced (formula-lock based) concurrency control protocol, and the steged database architecture. It is independently developed based on the Linux high-level security database system. Ministry of Science and Technology "863" Database Group of the major projects comments LogicSQL database "It is the only hope that China’s database products will be able to contend with America’s mainstream database products in the next few years." Access control policies are security policies that govern access to resources. It can be applied to several new types of databases. In this paper, we discuss access control in multilevel database management systems applies and illustrate the main applies of security mechanisms in the LogicSQL database system.