A dual working mode mobile robot system based on visual guiding and visual servoing

A dual operational modes mobile robot system based on visual guiding and visual servo control is presented.This system consists of a mobile robot with a two-axis manipulator and a tele-operation station.In the visual guiding mode,for the robot works in an open loop visual servo control mode,the manipulating burden of the operator is reduced largely.In the visual servo mode the robot can locate the position of the target assigned by the operator and pick it up by its manipulator.With the help of the operator,the difficult problems of finding and handling a target in a complicated environment by the robot Can be solved easily.     

Integrated Square Error of Hazard Rate Estimation for Survival Data with Missing Censoring Indicators

Journal of Systems Science and Complexity - The problem of hazard rate estimation under right-censored assumption has been investigated extensively. Integrated square error (ISE) of estimation is...     

基于特征相关学习的网页信息提取方法

为了给出网页信息提取方法的数学形式化的理论分析,首先用一维空间域的信息函数来表示网页信息,并通过分析网页过滤过程,推导出网页信息过滤定理.然后通过分析网页的相似性,推导并提出一种基于相关过滤的网页特征信息的提取理论.在这个理论基础上,融合基于标识规则和基于内容规则的两种方法,提出一种基于特征相关学习的网页信息提取方法.导出的特征提取理论和实验结果表明这种方法具有较好的准确率.     

快速数字电平转换电路IP核设计

基于IP核的技术设计了一种快速数字电平转换电路.采用电压-电流-电压的方式实现不同电压域的电平转换,引入单稳态延时电路和快慢速通道提高电平转换速度和降低静态功耗,并给出了与标准CMOS工艺兼容的扩展漏极高压MOS管的优化设计.仿真结果表明:在将-5～ 5V电压域的数字电平转换成0～ 12V的电压域时,其延时可低于10ns.     

一种基于比例电流的欠压保护电路的设计和实现

对传统欠压保护电路的缺点进行了分析,给出了一款基于比例电流的欠压保护电路,该电路有两个特点:电路结构简单容易实现,采用了Widlar电流源结构,不需要额外的外部基准;电路结构设计中,考虑了器件的温度特性,保证了电路的翻转阈值和迟滞量在正常温度范围内偏差不大.在基于0.6 μm的BiCMOS工艺库下对该电路进行了仿真验证,结果表明:在不同的模型下,阈值最大偏差为50 mV,在不同的温度下,阈值最大偏差为110 mV;该电路可应用于开关电源芯片中.     

考虑松动圈影响的公路隧道大直径竖井围岩压力计算方法

为研究公路隧道大直径竖井围岩压力计算方法,基于极限平衡法推导,并与官田竖井实测数据进行了对比验证,最后分析了竖井直径、侧压力系数、围岩等级对竖井围岩压力的影响规律。结果表明:1）与实测数据对比结果显示,本文公式的平均误差度12.85以内,相比其他公式的误差度在180以上,使相对误差减小了167.15以上,可指导工程人员进行竖井的施工设计。2）竖井开挖直径越大,竖井井壁围岩压力越大,但是围岩压力的增长幅度随直径增大而逐渐减弱。3）在未达到极限深度之前,侧压力系数越大,竖井井壁围岩压力越大;达到极限深度以后,不同侧压力系数下井壁的围岩压力一样大。侧压力系数越大,井壁围岩压力随竖井深度的增长越大,更快达到最大井壁围岩压力,即极限深度越小。4）围岩等级越高,竖井的井壁围岩压力越小,在达到极限深度之后的围岩压力也越小。     

基于工业基础类标准的建筑信息模型数据交互及应用

针对当前工业类基础(IFC)标准文件的开发应用存在文件格式转换繁杂、数据互操作性弱及信息有效利用率低等问题,提出一种IFC模型数据映射至数据库、BIM模型在Web端重构及信息在线可视化分析的实施方法。基于Web框架,搭建IFC标准文件映射至关系型数据库的应用框架。该应用框架利用JavaScript语言对IFC标准文件深度解析,采用Python语言将IFC模型数据和建筑全生命周期有效信息储存至关系型数据库,结合实际案例及分析,展现并验证该应用框架的实施效果。结果表明：该方法可实现项目数据交互的完整性和高效性,支持建筑全生命周期相关应用的二次开发;同时融合智能建造技术和科学管理,提升BIM信息管理的有效性,促进建筑业数字化发展和智能化应用拓展。     

Dynamic inhomogeneous S-Boxes in AES： a novel countermeasure against power analysis attacks

Substitution boxes (S-Boxes) in advanced encryption standard (AES) are vulnerable to attacks by power analysis. The general S-Boxes masking schemes in circuit level need to adjust the design flow and library databases. The masking strategies in algorithm level view each S-Box as an independent module and mask them respectively, which are costly in size and power for non-linear characteristic of S-Boxes. The new method uses dynamic inhomogeneous S-Boxes instead of traditional homogeneous S-Boxes, and arranges the S-Boxes randomly. So the power and data path delay of substitution unit become unpredictable. The experimental results demonstrate that this scheme takes advantages of the circuit characteristics of various S-Box implementations to eliminate the correlation between crypto operation and power. It needs less extra circuits and suits resource constrained applications.     

Effect of Membrane Thickness on Core Release Rate of Microcapsule

Membrane thickness of microcapsule is measured by op-tical microscope duplex focusing,the core release rate iscalculated by theoretical formula,and the effect of mem-brane thickness on release rate is revealed.As a result,with changes of formaldehyde dosage,complex coacerva-tion times,core dosage,agitation speed and emulsifica-tion time,membrane thickness and apparent diffusioncoefficient are of great importance on core release rate,but membrane thickness is dominant.     

Chi-square Distance在协议异常检测中的应用

针对Juan M提出的一种基于马尔可夫链的随机协议异常检测模型和评估方法存在的不足进行改进．改进后的模型增加了一些必要的状态，初始概率和转换概率更加精确．实验表明，将Chi—Square Distance和马尔可夫链方法相结合来检测协议异常，可克服原方法的不足，能有效检测到SYN Flooding攻击．