OPTIMAL PWM BASED ON REAL—TIME SOLUTION WITH NEURAL NETWORK

A novel concept of neural network based control in pulse-width modulation(PWM)voltage source inverters is presented.On the one hand,the optimal switching an-gles are obtained in real time by the neural network based controller；on the other hand,the output voltage is ad-justed to fit the expected value by neural network when input voltage or loads change.The structure of neural network is simple and easy to be realized by DSP hard-ware system.No large memory used for the existing opti-mal PWM schemes is required in the system.Theoreticalanlysis of the proposed so-called sparse neural network is provided,and the stability of the system is proved.Un-der the control of neural network the error of output volt-age descends sharply,and the system outputs ac voltage with high precision.     

嵌套网格性流动数值模拟用于风洞洞壁干扰研究

运用嵌套网格技术和Navier-Stokes数值模拟对机翼半模和翼身组合体试验时风洞的四壁干扰进行综合模拟，评估和修正，计算格式在空间上采用中心有限体积离散，在时间上采用多步Runge-Kutta时间步长格式进行积分，计算结果证明了该方法的可行性和优越性。     

空中客车A340—600首次亮相中国

空中客车公司制造的A340-600飞机飞抵上海,给了我们一个亲眼目睹这种目前空客最大的、也是世界上机身最长的飞机。     

C—17起落架寿命和部件支援

报告论述了C－17起落架帮助，轮胎和刹车部件，是军用飞机起落架寿命周期管理计划系列的第二部分，第一部分论述的是C－17飞机临界断裂和起落架部件的连续性。     

FL—2风洞大攻角自动转γ接头实验技术软件设计

本文旨在阐明FL－2风洞大攻角自动转γ接头试验技术应用软件的开发，研制，实现过程，同时介绍了软件的组成，功能，运行情况。