Hybrid Force and Vision-Based Contour Following of Planar Robots

Manipulators interacted with uncalibrated environments have limited dexterity due to constraints imposed by unknown environments. However, to perform science or industrial operations, it is necessary to be able to position and orient these manipulators on targets in order to accomplish required control tasks. This article describes how one might enhance manipulator dexterity for planar contour following tasks using hybrid force and vision-based control. The proposed control approach can guarantee task precision employing only a single-axis force sensor and an imprecisely calibrated CCD camera whose optical axis is perpendicular to the planar workspace. The goal of the autonomous task is to drive an instrument mounted on the end-effector of a planar robotic manipulator to follow a visually determined planar contour and continue tracking the contour in desired pose, contact force, and speed, all demanding time-varying, with precision. The proposed control architecture is suitable for applications that require simultaneous force and pose control in unknown environments. Our approach is successfully validated in a real task environment by performing experiments with an industrial robotic manipulator.     

VNC多媒体数据实时传输的研究与实现

针对VNC在传输多媒体数据时高带宽、低帧率的缺陷,在分析现有的编码方法和混合远程显示协议的基础上,提出了一种启发式方法一局部压缩法.该方法通过统计像素点的像素值变化频率,检测出桌面上的高频区域,并使用H.264编码该高频区域,对于桌面上的其它低频区域仍然采用VNC原有的编码方法.实验结果表明,该方法能够达到视频流畅播放所要求的帧率,同时能够有效地降低了网络带宽和CPU利用率.     

一种新的XML编码方案

提出了配比查询的概念,分析了现有XML编码方案在应用于配比查询时的不足,提出了一种新的XML编码方案,并给出了相应的查询算法。     

基于HVS分类及邻域搜索的快速分形图像编码

针对基本分形图像编码算法时间过长的问题,提出了一种基于HVS分类及邻域搜索的快速算法。根据HVS特性将子块分为平滑类子块和非平滑类子块,对于平滑类子块直接存储其均值,以减少需要搜索匹配父块的子块数;对于非平滑类子块,从离其最近的父块开始搜索,在搜索父块时,剔除与当前子块的近似度不满足要求的父块,并引入误差阈值和搜索父块的最大次数来控制子块的搜索过程。实验结果证明,该算法大大提高了编码速度。     

H.323协议栈中ASN.1模块的设计与实现

对ASN．1及PER编码规则作了简要介绍，接着提出了一种ASN．1编解码模块在H．323协议栈中的设计与实现的方案。     

The effects of divided attention on encoding processes in memory: Mapping the locus of interference.

Despite the detrimental effects of divided attention at encoding on later memory performance, results described in the literature do not unequivocally specify which processes are interrupted during encoding by participants' occupation with a concurrent task. Using a processing analysis framework where the encoding process is viewed as a multiphase mental activity, the current research investigated this issue using a new differential temporal interference paradigm where the study phase of single words was interrupted at different temporal segments. In two experiments, we used performance on both memory and online choice reaction time tasks to assess whether such differential interference would produce different degrees of reduction in participants' later memory performance, as well as changes in the attentional resources required to execute each of the encoding phases. Measures of memory and concurrent task performance in the two experiments converged on similar patterns, showing that all phases of encoding are affected by the concurrent task. However, the initial encoding phase, which is tentatively associated with the initial registration of information, seems especially vulnerable to interference. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

部分向量奇偶位切分的LFSR重新播种方法

提出一种基于部分测试向量奇偶位切分的LFSR重新播种测试方法.针对确定测试集中各个测试向量包含确定位的位数有较大差异以及测试向量所含的确定位大多连续成块的特点,通过奇偶切分部分确定位较多的向量,使得编码压缩的LFSR度数得到有效降低,从而提高了测试数据压缩率.其解压缩电路仍然采用单个LFSR进行解码与切分向量的合并.与目前国际同类编码压缩方法相比,具有测试数据压缩率高、解压硬件开销低、测试数据传输协议简单等特点.     

基于AVS—M和DM642视频服务器的研究

本文完成了视频服务器的硬件设计，针对如何充分发挥DM642硬件平台的处理能力，提出了关于AVS-M算法的编码优化方案．该方案是对软件框架流程进行仔细考虑后提出的，避免了冗余操作，针对存储系统对各部分的数据结构进行了设计．而且通过DMA实现了计算与数据传输的并行处理。     

手机短信模块在.NET平台下实现与应用

首先介绍了用于手机短信的串口通信、AT指令以及发送模式等相关知识,然后重点解析了手机短信的编码方法,包括7-bit编码和UCS2编码等,并给出了在.NET平台下用C#实现的主要代码。文章最后还描述了手机短信模块在某一个实际的监视系统中的集成与应用场景。     

C编写Tcl文件系统监测扩展

ReadDirectoryChangesW是Windows系统下用于监测文件系统变化的API函数。使用Tcl的C扩展API对其进行必要的整合与包装,分别从同步调用与异步调用两个角度介绍了如何实现阻塞与非阻塞的Tcl模块,并在此基础上结合Tcl的时间通知机制,实现了单线程非阻塞的文件监控模式。