基于因特网的液压系统远程控制的基础研究

本文以液压系统为被控对象,对在因特网环境下的远程控制系统提出了具有挑战性的研究.仿真及实验结果表明,采用适当的补偿器结构和时延预测算法可以比较好地解决因特网在传递控制信息时的时延及时延的不确定性对液压远程控制系统的影响,使采用因特网的机械运动的远程控制成为可能.本文还提出了实现这种远程控制时需要对远程端采样信息进行适当的处理;为保证在相同的网络条件下进行实验研究,需要构筑能对因特网网络时延及时延的不确定性进行再现的因特网远程控制实验系统.     

武器装备故障诊断专家系统平台的初步设计

介绍了专家系统平台的概念及在军事领域中应用的意义.详细描述了建立专家系统平台的知识表示和推理方式等关键内容.提出了一种多知识表示、多推理方式的故障诊断专家系统平台.     

Self‐Powered Trajectory,Velocity, and Acceleration Tracking of a Moving Object/Body using a Triboelectric Sensor

Motion tracking is of great importance in a wide range of fields such as automation, robotics, security, sports and entertainment. Here, a self‐powered, single‐electrode‐based triboelectric sensor (TES) is reported to accurately detect the movement of a moving object/body in two dimensions. Based on the coupling of triboelectric effect and electrostatic induction, the movement of an object on the top surface of a polytetrafluoroethylene (PTFE) layer induces changes in the electrical potential of the patterned aluminum electrodes underneath. From the measurements of the output performance (open‐circuit voltage and short‐circuit current), the motion information about the object, such as trajectory, velocity, and acceleration is derived in conformity with the preset values. Moreover, the TES can detect motions of more than one objects moving at the same time. In addition, applications of the TES are demonstrated by using LED illuminations as real‐time indicators to visualize the movement of a sliding object and the walking steps of a person.     

利用动态链接表的二值图像目标区域分割

为了准确、快速地对二值图像中的连通区域进行标识,分割出各个目标物体的位置和面积.提出了一种基于动态链接表的连通区域标记方法.以目标像素线段为基本处理单元,令像素扫描和连通标识同步进行,同时,建立所用连通体的动态链接表,仅需一次扫描便可根据链接关系将图像中所有目标物体分割出来.定义"中空"的4邻域模板.通过特定的判断运算...     

透过上海世博会看信息化时代新闻传播技术规律观

上海世界博览会既是全球化信息化时代人类科技创新成果的展示舞台,又是世界各国文明交流、全球文化全面互动平台,胡锦涛总书记在与世博会主题有关的不同场合强调按信息化时代的新闻宣传创新、要适应信息化时代新闻传播的特点和规律.     

认知无线Mesh网络跨层设计研究

传统网络的分层设计不能满足具有特殊QoS需求的无线宽带业务,无法应对动态频谱接入的无线通信环境。采用联合开放、架构灵活的跨层设计研究无线Mesh网络接入技术日渐成为热点。本文首先介绍了跨层设计的起源、分类,然后分析了认知无线Mesh网络跨层研究的挑战、难点及最新进展,并提出利用跨层设计实现路由及频谱管理的一种构想,最后展望了认知无线Mesh网络跨层研究的新方向。     

拉曼-纳斯衍射声光Q开关的实验研究

实验研究了拉曼-纳斯(R-N)衍射的声光相瓦作用长度与声波光波参数之间的关系,确定了最佳声光相互作用长度.在此基础上,分别设计以水和TeO2晶体为声光介质的R-N衍射Q开关器件,测量了器件的衍射效率、衍射角和插入损耗等参数.应用TeO2晶体开关器件调制长脉冲Nd:YAG/KTP激光器,当重复频率为10 kHz时得到了脉...     

退火工艺对Al离子注入的4H-SiC表面形貌的影响

通过应用多次Al离子注入和CVD中的高温退火技术,在SiC片表面形成了p型层。p型层中各深度下Al的浓度均为110¹⁹cm^-3,层厚为550nm。本文应用三种不同的退火工艺对注入后的SiC进行退火。通过测量和比较表面粗糙度,发现通过石墨层覆盖来保护表面的退火工艺可以很好的阻止SiC表面在高温退火下的粗化,粗糙度保持在3.8nm。通过其他两种(在氩气保护下、在SiC保护片的覆盖下)退火工艺退火所得到的表面有明显的台阶,粗糙度分别为12.2nm和6.6nm。     

Voltage acceleration and t63.2 of 1.6–10 nm gate oxides

Gate oxide reliability data collected over a considerable period of time were compiled to assess the voltage acceleration and the time to breakdown as function of oxide thickness. These data cover a range from 1.6 to 10 nm and can be used as benchmark for technologies that are still using gate oxide in this thickness range. The data form well-defined bands for each of the voltage acceleration models. The functional dependence of the parameter on oxide thickness depends strongly on the voltage acceleration model. The accuracy of the voltage acceleration parameters determined for the different acceleration models is studied. The time to breakdown at one voltage spans many time-decades if the data covering the entire thickness range are plotted in one graph. Therefore, the use of a model-free value, the voltage to get 63.2% breakdown at a certain fixed time, is proposed for plotting the data taken in the wide oxide thicknesses range, instead of normalizing the time to breakdown to a certain voltage using one of the voltage acceleration models. Based on the results a self-consistent test of the voltage acceleration models is introduced. This parameter also supports the t_bd power law and therefore the hydrogen release model when plotting the voltage acceleration parameter of the exp(V)-model versus the inverse model-free gate voltage to get 63.2% breakdown at a fixed time.     

基于最小自由度优先原则的任意多边形模块布局算法

给出了直角多边形模块自由度的定义和公式,扩展了最小自由度优先原则,使算法能够处理任意直角多边形模块以及有相对约束的模块.实验结果说明该方法在布局效果和效率上都有良好的表现.