一种新的基于在线采样的多物体跟踪方法

跟踪多个运动物体,尤其是在遮挡过程中跟踪多个运动物体,是计算机视觉领域一个重要但具有挑战性的问题.该文提出了一种新的在线采样、更新学习和分类的跟踪框架来处理多物体跟踪问题.首先,对遮挡发生前若干帧的各物体进行块采样,作为训练样本进行在线分类器设计.各帧的物体区域也在线进行块采样,并用这些分类器来进行分类标号.如果遮挡没有发生,一些新的训练样本被添加用来更新分类器.当遮挡发生时,根据标号结果,前景区域被分割成多个目标物体.和以往方法相比,新方法不依赖于一些假设条件,如场景深度信息、物体的先验模型(比如形状、种类、区域内颜色各向同性、运动规律等),具有更好的适应能力.实验结果验证了该文方法的稳定性和有效性.     

Using simulation and multi-criteria methods to provide robust solutions to dispatching problems in a flow shop with multiple processors

Dispatching rules are important to the performance of a manufacturing system. Selective applications of different priority rules at different processing stages in a multiple workstation manufacturing system have a positive impact on shop performance. This type of problem is a combinatorial dispatching decision. However, no dispatching rule can consistently produce better performance than all other rules under a variety of operating conditions and criteria. It is the purpose of this study to provide a robust solution for a dispatching decision that will have ‘good’ performance under different operating scenarios. In this paper a simulation case of a flow shop with multiple processors is proposed, specifically a multi-layer ceramic capacitor manufacturing system. Two multiple criteria decision-making methods – techniques for order preference by similarity to ideal solution (TOPSIS) and an analytic hierarchy process (AHP) – in combination with Taguchi orthogonal array are used to find the most suitable dispatching rule for every workstation. The results show that for 15 production scenarios and 4 criteria this combinatorial dispatching rule is robust, in the sense that it outperforms other commonly employed strategies.     

Real-time reliability prediction for dynamic systems with both deteriorating and unreliable components

As an important technology for predictive maintenance, failure prognosis has attracted more and more attentions in recent years. Real-time reliability prediction is one effective solution to failure prognosis. Considering a dynamic system that is composed of normal, deteriorating and unreliable components, this paper proposes an integrated approach to perform real-time reliability prediction for such a class of systems. For a deteriorating component, the degradation is modeled by a time-varying fault process which is a linear or approximately linear function of time. The behavior of an unreliable component is described by a random variable which has two possible values corresponding to the operating and malfunction conditions of this component. The whole proposed approach contains three algorithms. A modified interacting multiple model particle filter is adopted to estimate the dynamic system’s state variables and the unmeasurable time-varying fault. An exponential smoothing algorithm named the Holt’s method is used to predict the fault process. In the end, the system’s reliability is predicted in real time by use of the Monte Carlo strategy. The proposed approach can effectively predict the impending failure of a dynamic system, which is verified by computer simulations based on a three-vessel water tank system.     

Multivariable direct adaptive decoupling controller using multiple models and a case study

In this paper, a multivariable direct adaptive controller using multiple models without minimum phase assumption is presented to improve the transient response when the parameters of the system jump abruptly. The controller is composed of multiple fixed controller models, a free-running adaptive controller model and a re-initialized adaptive controller model. The fixed controller models are derived from the corresponding fixed system models directly. The adaptive controller models adopt the direct adaptive algorithm to reduce the design calculation. At every instant, the optimal controller is chosen out according to the switching index. The interaction of the system is viewed as the measured disturbance which is eliminated by the choice of the weighing polynomial matrix. The global convergence is obtained. Finally, several simulation examples in a wind tunnel experiment are given to show both effectiveness and practicality of the proposed method. The significance of the proposed method is that it is applicable to a non-minimum phase system, adopting direct adaptive algorithm to overcome the singularity problem during the matrix calculation and realizing decoupling control for a multivariable system. Supported by the National Natural Science Foundation of China (Grant Nos. 60504010, 60864004), the National High-Tech Research and Development Program of China (Grant No. 2008AA04Z129), the Key Project of Chinese Ministry of Education (Grant No. 208071), and the Natural Science Foundation of Jiangxi Province (Grant No. 0611006)     

建构主义教学法在JAVA程序设计课程中的改革与应用

大学计算机相关专业中,学生在理解和掌握知识的同时更关注自己的学分总数和学分积点,学习兴趣和能力培养成为获取毕业证书和学位证书的一个副产品。导致学生难以产生浓厚的程序设计兴趣,对专业课程的掌握不够扎实。因此改变学生的学习心态和认识尤为重要,基于建构主义的教学方法在专业课程中的应用则会起到促进的效果,让学生在主动学习,享受学习的过程中掌握计算机课程的核心技术,让证书成为一个必然的副产品。     

基于MAF模型的串扰时延故障的测试矢量生成

随着深亚微米技术,串扰噪声问题越来越严重。利用MAF模型的基本思想,探讨了一种串扰时延最大化算法,并且利用被修改的FAN算法,生成测试矢量。对于一条敏化通路,利用被修改的FAN算法适当地激活相应的攻击线和受害线,使电路在最恶劣情况下引起最大通路时延,从而实现更有效的时延测试。在标准电路ISCAS’85上进行实验验证,结果表明:该算法对于多攻击线的串扰时延故障的测试矢量产生是有效的。     

多工作模式产品配色意象的灰色评价方法

针对产品开发过程中的色彩规划问题,考虑多工作模式产品的配色特征,构建一种多工作模式产品的配色意象评价模型.基于灰色关联分析法建立产品方案色彩与意象之间的关联模型,运用灰色聚类法判断产品配色方案的意象值;将产品各工作模式下的配色意象同时作为评价属性并赋予相应的权值,进行综合评价.文中方法兼顾了多工作模式产品色彩面积的可变性和消费者主观意象的不确定性,将多工作模式产品的配色意象评价方法置于灵活、直观的框架中.最后以工程机械产品为应用实例,证明该方法较单属性评价方法更为贴近消费者的主观意象.     

基于压缩域互补分割的视频多描述编码研究

鉴于数字视频在空间域及时间域上的信息相关性,提出在视频压缩过程中实现多描述编码的方法.算法以H.263为参考标准,在图块及运动估计的DCT域上进行系数划分,通过对少量重要信号的重复分配来保证单个描述的接收质量.同时,系数域的对角分割又使各个描述间具有较强的信号互补性.实验结果表明,算法具有描述冗余率低、编/解码直接快速、压缩率高等良好的MDC特性,是保障视频传输业务可靠性和实时性的有效方法.     

基于粒子群的CDMA功率和速率联合控制算法

提出了基于效用函数的CDMA网络下行链路的功率和速率联合控制最优化算法.在这类算法中,效用函数为非凸函数,经典的最优化理论很难解决这类问题.将粒子群优化方法应用于算法的非凸性设计,并通过仿真算例证明了该算法能有效解决非凸优化问题,且可保证系统的公平性.     

双酚A型聚碳酸酯快速拉伸过程的分子动力学模拟

本文采用用分子动力学方法研究了双酚A型聚碳酸酯的快速拉伸过程.采用COMPASS力场和NPT系综研究了应力应/变关系、能量/应变关系等.应力-应变曲线的研究结果显示,前"屈服点"和后"屈服点"分别为0.14和0.17,应变≤0.05为"弹性区域".0.14<ε_(xx)<1.05的区域为"塑性区域",ε_(xx)>1.05属于"硬化"区.能量-应力关系的研究结果显示,在应力-应变呈线性关系的"弹性区域",体系的总势能及各势能分量随应变增大发生不规则的波动.为了从能量的角度解释PBC-PC在外部拉伸条件下的应变情况,本文还研究了体系总能量与各能量分项,与应变的关系,对链结构与能量分项的关系进行了讨论.