An embedded strong discontinuity model for cracking of plain concrete

A numerical model formulated within the framework of a nonsymmetric strong discontinuity approach for fracture simulations of plain concrete is presented. The model is based on the fixed crack concept and makes use of the concept of the elements with embedded discontinuities. Discontinuity segments of individual elements are considered to form a C⁰-continuous path. Enforcement of continuity of the crack path across adjacent elements is established by a partial domain crack tracking algorithm. Orientation of individual crack segments is derived from a nonlocal strain field. The capabilities of the model are shown by means of numerical examples.     

弹目信息在纯方位末制导中的应用

在考虑“被动测量”的条件下，探讨了通过综合利用弹目信息来获取制导所需信息的方法，设计了一种适合被动雷达寻的末制导的运动跟踪滑模制导律；根据自适应推广Kalman滤波技术设计了目标跟踪滤波器；给出了简化的末制导数学模型，并进行了仿真计算。结果表明：所给方法可以较好地提高导弹的制导精度。     

基于.NET框架的Web电子邮件跟踪技术

设计并实现了一种基于Http处理管道模型的电子邮件跟踪方案,通过自定义的HttpModule类能够有效拦截HttpRequest以实现个性化的电子邮件跟踪需求,且有更强的通用性。     

Adaptive actor-critic learning for the control of mobile robots by applying predictive models

In this paper, we propose two methods of adaptive actor-critic architectures to solve control problems of nonlinear systems. One method uses two actual states at time k and time k+1 to update the learning algorithm. The basic idea of this method is that the agent can directly take some knowledge from the environment to improve its knowledge. The other method only uses the state at time k to update the algorithm. This method is called, learning from prediction (or simulated experience). Both methods include one or two predictive models, which are assumed to be applied to construct predictive states and a model-based actor (MBA). Here, the MBA as an actor can be viewed as a network where the connection weights are the elements of the feedback gain matrix. In the critic part, two value-functions are realized as a pure static mapping, which can be reduced to a nonlinear current estimator by using the radial basis function neural networks (RBFNNs). Simulation results obtained for a dynamical model of nonholonomic mobile robots with two independent driving wheels are presented. They show the effectiveness of the proposed approaches for the trajectory tracking control problem.     

基于虚拟现实交互的跟踪软件模块设计

开放软件体系结构为跟踪在虚拟环境和增强现实应用中的输入设备和多形态数据的不同任务提供运行框架.跟踪体系结构简化了传统虚拟现实开发包进行系统开发和硬件设备维护的方式.通过使用基于XML的面向对象设计技术实现了这个目的.     

一种高效的移动Agent控制机制

在传统分布式系统中,由于任务之间具有明确的依赖关系,所以有很多方法来实现任务的控制。但这些方法已经不适于移动Agent环境,其根本原因在于移动Agent之间不存在那种“自然”的依赖关系。文章提出了一种移动Agent的控制机制,它基于以AgentTracer为中心以Agent影子为辅助的Agent追踪方法,结合能量概念来实现移动Agent的控制,并说明这种方法是高效的。     

跟瞄伺服快速调转的数字控制

针对形如K／[(TS 1)S]的跟瞄伺服系统采用双 模控制算法实现该系统在大角度偏差情况下的快速调转，并且叙述了这种方法的数字实现。     

机动目标跟踪的IMM和IMMF-LS自适应滤波算法

介绍了一种跟踪机动目标的交互式多模型 (IMM)自适应滤波算法 ,并在其基础之上介绍了一种基于状态的扩充具有固定延时的平滑IMM算法 (IMMF -LS) ,分别采用了Singer模型和“当前”统计模型与CA模型进行交互运算。蒙特卡洛仿真结果表明了IMM具有明显的综合多模型的优点 ,IMMF -LS的跟踪精度明显高于IMM算法。     

A machine vision system for enhancing the teleoperation of an industrial robot

This paper describes a real-time vision system that enhances the teleoperation of a servicing tool used in the heat exchangers of nuclear power plants. The vision system is used to track the position of the tool as it moves over a sheet of tube ends. A map-based strategy is adopted for the estimation of the position. The system incorporates a novel method for a foreshortening correction that is applied prior to map referencing. A hypothesize and verify scheme locates two image features that correspond to two map features. An efficient scheme for extracting image features is developed to locate these two features (tube-end centers) in the image. Two different types of heat-exchanger tube sheets are accounted for. They are those with tube ends placed in a square grid and those with tube ends placed in a triangular grid. The map-based strategy minimizes the cumulative errors in the estimate of the tool head position. The resulting low-cost system has been tested on synthetic and real data. Performance results are given.     

A per-object-granularity tracking mechanism and systemfor interactive TV viewership estimation and program rating in real time

TV program ratings directly affect the decisions of advertisers and TV stations program offerings. TV program providers use television ratings reports to offer appropriate programs as well as attract advertisers. In this paper we propose a framework for TV audience estimates and program ratings using a per-object-granularity tracking mechanism for interactive TV content tracking in real time. It can be applied to live TV broadcasting environments as well as recorded broadcasting environments. The major components of the proposed tracking architecture are an interactive TV content creation tool powered by hotlinked video technology, a tracking information delivery framework with live interactive content insertion capability, an interactive TV content receiver, and tracking servers. The proposed mechanism and system in this paper enables a broadcast station or a rating agency to automatically perform tracking functions in real time based on viewer actions as well as on the content of audiovisual programming.