Kalman Filter for Generalized 2-D Roesser Models

The design problem of the state filter for the generalized stochastic 2-D Rocsser models, which appears when both the state and measurement are simultaneously subjected to the interference from white noise, is discussed. The wellknown Kalman filter design is extended to the generalized 2-D Roesser models. Based on the method of ＂scanning line by line＂, the filtering problem of generalized 2-D Roesser models with mode-energy reconstruction is solved. The formula of the optimal filtering, which minimizes the variance of the estimation error of the state vectors, is derived. The validity of the designed filter is verified by the calculation steps and the examples are introduced.     

基于项目簇偏好的用户聚类算法

传统算法基于用户项目评分矩阵来进行推荐,存在冷开始、稀疏性等问题,邻居相似性只鉴于用户共同评价的项目,没有考虑项目本身的属性关系;在整个用户空间搜寻最近邻居,实时性差。针对这些问题,提出基于项目簇偏好的用户聚类算法,首先基于项目属性特征对项目进行聚类,然后再利用用户对项目簇的偏好对用户进行聚类,最后在和目标用户最相似的几个聚类中搜寻邻居用户,从而压缩搜寻空间,提高了搜寻速度。实验表明,该算法通过降低稀疏性、冷开始等问题,增强实时性,提高预测精度。     

延时容忍网络中基于内容的信息传播机制研究

延时容忍网络(Delay-tolerant Network)是一种实用的受限网络模型,它具有延迟长、网络分割、节点能力受限等特点.在这种网络环境下,由于网络拓扑不断变化,节点间端到端的通信路径并不存在,传统的路由协议无法有效的运作.针对延时容忍网络的特点,提出了一种基于内容的信息传播机制.在该机制中,每个节点根据相遇历史信息决定是否对所获得的信息进行转发.实验结果表明,该信息传播机制在通信延迟和信息开销方面,较传统OCBD协议和Epidemic协议有所提升.     

基于XPE的嵌入式DVR系统的设计与实现

介绍了一种基于XPE的嵌入式DVR系统的设计与实现方法.该系统采用英特尔凌动处理器作为硬件平台,采用Windows XP Embedded with SP2作为软件平台,能有效克服目前嵌入式DVR处理性能有限而PC式DVR配机繁琐与兼容性问题及不稳定因素.详细介绍了XPE操作系统的开发过程以及FBWF写保护功能的原理和实现方法.基于该方案设计的嵌入式DVR系统经过实际测试,达到了预期的设计效果.     

Development of a reference strain approach for assessment of fracture response of reeled pipelines

As a result of recent increase in exploitation of hydrocarbon resources in harsher environments and also installation techniques which utilize the materials plastic deformation capacity, accurate assessment of fracture response of pipelines subject to large plastic strains (e.g., typical of reeled pipes) has attracted particular interest nowadays. In this paper, an approach, based on the evaluation of the J-integral, is developed for assessing the integrity of such pipelines, manifested in a model of a pipeline with a circumferential part-through crack subjected to plastic bending. The proposed approach is an extension of the reference strain method developed earlier by other researchers, and takes advantage of the displacement controlled loading nature in such pipes (thus being suitable for Strain Based Design methodologies), and the resulting high strain levels, which often cause fracture response of the material in the plastic regime. The developed formulation relates the fracture response of the pipe (in terms of the non-dimensionalized J-integral) as a linear function of the axial strain in the pipe at its uncracked state. A series of 300 3D nonlinear finite element models using the ABAQUS software were analyzed in preparation of the equation that could assess the fracture response of such pipes with great accuracy. The resulting equation, calibrated by the finite element results, can predict the fracture response of pipes with a maximum error of 2% for a practical uncracked material strain range of 1.5% ? ε_unc ? 4%.     

PROFINET CBA组件的应用实现

PROFINET是基于工业以太网的开放标准,PROFINET基于组件的自动化（CBA）技术通过采用标准自动化组件实现了分布式自动化系统简单高效的互联。本文研究了PROFINET CBA的通信原理、模型,基于PI组织的PROFINET CBA Runtime Source代码开发了PROFINET CBA自动化组件,实现了PROFINET CBA组件之间的实时通信,对于构建基于PROFINET CBA的分布式通信系统具有一定的工程意义。     

跨校教学在建筑系研究生班设计课程中的应用

本文提倡以人的终身教育为目标的教育思想;结合香港社会和经济特点,介绍了以课题为核心和以网站为基础的高等 教育改革的思想。最后介绍了香港大学建筑系研究生一年级与清华大学和柏林艺术大学的一项合作设计。     

电解金属锰废渣返土还真的试验研究

介绍了电解金属锰废渣专用基示范工程测产验收情况，着重对电锰渣返土还真立论依据及技术要点进行了分析。     

An Improved Particle Swarm Optimization Algorithm Based on Ensemble Technique

An improved particle swarm optimization （PSO） algorithm based on ensemble technique is presented. The algorithm combines some previous best positions （pbest） of the particles to get an ensemble position （Epbest）, which is used to replace the global best position （gbest）. It is compared with the standard PSO algorithm invented by Kennedy and Eberhart and some improved＇PSO algorithms based on three different benchmark functions. The simulation results show that the improved PSO based on ensemble technique can get better solutions than the standard PSO and some other improved algorithms under all test cases.     

Al2O3基纳米复合陶瓷刀具切削不锈钢的实验研究

实验研究了Al2O3基纳米复合陶瓷刀具ASs与LTN连续干切削奥氏体不锈钢1Cr18Ni9Ti时的切削性能。结果表明,在相对较高的切削速度下,两种刀具表现出较好的切削性能,其中ASs刀具的主要磨损机制是粘结磨损和微崩刃,而LTN刀具则主要是粘着剥落;在相对低速下切削时,两种刀具都发生粘结破损失效。