可编程控制器的时钟设立及时间控制

介绍了可编程控制器机内时钟的设定及时间控制的方法,给出了编程实例．     

改进的对称分布期望估计量的性质

本文证明了改进后的对称分布期望估计量W_p在一定条件下具有无偏性和强相合性,并给出了方差的上界,其中:W_p.=1/n-2[np] sum from a-[ap] to i=[ap]+1 X_(j),0≤p<1/2     

基于多流动态贝叶斯网络的音视频连续语音识别

针对说话时发音和口形的异步问题,提出了一个多流异步动态贝叶斯网络(DynamicBayesian Network,DBN)模型,以实现基于音视频特征的连续语音识别,在这个模型中,音频流和视频流在词节点同步,而在词节点之间,音视频流有各自独立的拓扑结构以及节点变量之间的条件依赖关系,同时词转移节点变量由音视频流共同确定,模型在词级别上体现了音视频流的异步性.采用连续数字音视频数据库的实验结果表明,在信噪比为O～30 dB的测试环境下,比较单流DBN模型和多流隐马尔可夫模型,平均识别率分别提高了8.68%和10.07%.     

计算机控制与检测气动换向阀试验台

介绍一种采用计算机控制与检测气动换向阀试验台的特点和测试系统设计。     

用moire技术测量平板玻璃折射率

本文描述了使用moire技术测量平板玻璃折射率的理论并进行了实验论证。测量方法简单且快捷。可精确测量任何透明材料的折射率。测量精确度可达10~(-5)。     

器外复杂换热的搅拌容器中液体不稳定传热计算

论述了器外复杂换热的搅拌容器中液体不稳定传热计算方法,对几种常见的这类情况进行了算式推导,并举例说明     

跟踪-微分器在全捷联制导中的应用分析

以仅能获取角度信息的全捷联导引头为研究对象,针对采用直接微分提取惯性视线角速率时存在的噪声放大问题,基于跟踪微分器设计了一种全捷联制导信息提取算法。结合导引头的性能指标要求,对3种不同形式跟踪微分器的提取效果进行了对比分析。仿真结果表明,采用非线性微分器进行惯性视线角速率提取,可以减小延迟时间,避免噪声放大,有效提高制导精度,具有一定的工程应用价值。     

Optimization of abrasive water jet cutting of ductile materials

Full factorial design of experiments was developed in order to investigate the effects of jet pressure, abrasive mixing rate, cutting feed, and plate thickness upon three response variables, surface finish of cutting wear zone, percentage proportion of striation free area, and maximum width of cut. The set of sixteen experiments was performed on each of the following two ductile materials: AISI 4340 (high strength low alloy steel, hardened to 49HRc) and Aluminum 2219. Analysis of Variance (ANOVA) was performed on experimental data in order to determine the significance of effects of different parameters on the performance measures. It was found that cutting feed and thickness were highly influential parameters, while abrasive mixing rate is influential upon surface roughness only. Strong interaction was found between jet pressure and workpiece material. Multi-criteria numerical optimization was performed in order to simultaneously maximize/minimize different combinations of performance measures.     

谐振式变换器电路结构分析

本文着重对电压源串联型谐振变换器的理论问题和电路结构作了分析，对电流源并联型谐振变换器也作了概略的介绍。