A Review on Class D Audio Power Amplifier Control Techniques

Although class D amplifier has high efficiency, its distortion is larger than linear counterparts due to switching behaviour of power transistors. It is the hotspot of power electronics and audio power amplifier that researching new control technique to improve fidelity of class D amplifier. In this paper, a few novel control techniques in class D audio power amplifier are reviewed.     

Finite Element Analysis of Concrete Structures Strengthened with Carbon Fiber Sheet

Stress redistributes after the concrete structures strenthened with carbon fiber reinforced polymer sheet. It is a question of secondary loading.Many scholars have studied it and got a lot of achievements.This paper summarizes the methods and analyzes their advantage and shortcoming. Based on it, a new method is proposed.The method is developing in large-scale general software-Ansys by using adding new elements, constitutive relationship, failure criterion,and so on.The calculation formula agrees with the experimental data.     

Application of SDL in the Digital System Design

As a standardized formal language, the SDL has widely been used in the software development. In order to extend its application field, it has been explored to use in hardware design.This paper gives a logical gate circuit-and gate as an example to explain the method of applying SDL to describe and simulate/validate the hardware characters by the SDT tool. The various logic circuits or digital circuits may be made to the SDL packages because the SDL supports the object oriented technology. These packages can be directly invoked in the design of the complex digital system, so it is possible to describe and simulate/validate the complex digital system.The experiment has proved that the application of SDL for hardware design is feasible and rather convenient.     

Effect of Reinforced-Concrete Deterioration on Structures

s:It is proposed that the research of the structural durability is necessary considering the structural damages under the effect of deterioration of reinforced concrete. The most common reasons, which cause the deterioration of structures in China, are reinforcement corrosion and freeze thaw cycles of concrete. Based on the summarizing of research works of the effect of reinforced concrete deterioration on structures, it is indicated that the structural durability research should be carried out either in view of material science or that of structural science, and should be also considered the interaction of several factors with uncertain nature instead of the determined individual factor analysis. The structural durability of serviceable should be paid much more attention while researching the durability of structural capacity. The effect of reinforced concrete deterioration on structural capacity, rigidity and durability should be researched henceforth.     

Optimization of Vehicle Frontal Wheel Orientation Parameters

Based on the theory of multi body dynamic, the paper established the front suspension model of vehicle. The uniform optimization object function, including the tolerance of front wheel orientation angles' practical value and set value under full load, and the changing value of each parameter during wheel fluctuating is put forward. Utilizing this model, the original suspension is optimized and the variation of each parameter with front wheel fluctuation is calculated. The optimized driving operation performance resulted from the analysis and application.     

Theory of RBV-Competitive Advantage of the Stock Company

China's stock market enters a stage where the competition's rules as well as the competition's environment are changing continuously,Under such circumstances,to gain the competition advantages is of vital importarce to the existence and development of China's stock companies themselves. As a result, the stock companies should have a thorough analysis of the RBV theory at present, and evaluate its applicability to China's stock companies, Then they should come up with some reformational measures,aiming at improving the competition advantages of domestic stock companies. There fore they are able to make measonable use of the company's resources and accomplish the organic unity combination of the company's valued resources and its strategic administration. These are the key measures used by stock companies to gain the competition cedvantges.     

Application of Intelligent Neural Network on Prediction of Time Series Signal

The research of neural network has been maturated both in theory and practical application since 1980's, and also been employed into the prediction and analysis of nonlinear time series signal in the field of signal process system. Concerning with the problem of time series signal prediction based on traditional neural network, such as black box, poor accuracy, and facing the shortage of post knowledge, this paper presents a different neural network prediction model from the traditional ones, based on intelligent neural cell model and employing the iterative prediction method. Through the example on stock price prediction, the prediction accuracy and practical value are proved.     

The GDSS Framework of Organization-Oriented Dynamic Alliance Based on Multi-Agent

The important strategy decision making system, one of the difficult problems of the research of Group Decision Support System, is an open complex huge system, which is almost non structure and hard to construct. In order to organize and take advantage of decision making departments more effectively, this paper presents the thought of combining Multi Agent System with Dynamical Alliance and set up the GDSS Framework of Organization Oriented Dynamic Alliance based on Multi Agent after analyzing the characteristics of MAS and Dynamical Alliance. Different departments can be organized more effectively on the three layer system structure composed of the strategy layer, the tactics layer and the operation layer. The decision making layer of each department is composed of the integrate decision making subsystem, which means that the decision making layer of each department can be used solely or be a part of Dynamic Alliance to make the important strategy decision and the system gets more flexible.     

A Integrate-Reset-Controlled Single Phase Power Factor Correction with High Efficiency

A novel single phase boost type power factor correction circuit is introduced .The converter's efficiency is greatly improved by improving on the traditional boost type power factor correction circuit. Integrate Reset Control circuit is adopted to realize unity power factor. The Integrate Reset Control high efficiency single phase boost type power factor corrector has these characteristics as follows: It's constant frequency operation, which is of advantage of the design of filter. The control circuit is very simple and no need for multiplier. The result is quiet perfect, the input current follows the input voltage very well. The efficiency is very high. The result of simulation and experiment proves the correction of theory analysis.