基于动态粒子群优化的目标跟踪算法

目标跟踪问题的关键在于如何寻找与目标运动状态匹配的运动模型;交互式多模型算法的模型集是根据先验信息确定的,它不随时间变化而变化,并且要求在模型集中任意时刻都存在描述目标运动模型;在实际中需要大量模型来描述运动;将粒子群优化和变结构多模型算法相结合,不仅能充分利用系统的实时量测信息,还能根据其先验信息调节优化算法结构;仿真表明,运用动态自适应粒子群优化算法实现模型集自适应,可以提高目标跟踪的精度和实时性。     

基于灰色预测模型和粒子滤波的视觉目标跟踪算法

结合灰色预测模型和粒子滤波,提出一种新的视觉目标跟踪算法.由于粒子滤波未考虑先验信息对建议分布产生的指导作用,不能很好地逼近后验概率分布,对此,采用历史状态估计序列作为先验信息,建立该序列的灰色预测模型来预测产生建议分布.与粒子滤波、卡尔曼粒子滤波和无迹粒子滤波进行对比实验,结果表明所提出的算法在视觉目标跟踪中具有更好的性能.     

引入前帧加权采样的粒子滤波目标跟踪算法

根据相邻帧间信息的强关联性,提出一种引入前帧加权采样的粒子滤波目标跟踪算法,解决了传统采样重要性重采样(SIR)算法由于引进提议分布(Proposal distribution)而需要严重依赖目标的系统状态模型的问题,可以理想跟踪运动状态不规则的目标.该算法提出的引入前帧加权采样思想不仅仅局限于基于序列图像的跟踪,而且可以推广到其它相关的领域,具有普适性和实用性.     

基于粒子滤波的多特征融合视频行人跟踪算法

针对车载视频行人跟踪问题,提出一种基于粒子滤波框架下的多特征融合跟踪算法。为克服车载视频中行人运动与摄像机运动产生的非线性和非高斯性,采用基于蒙特卡罗抽样的粒子滤波跟踪算法,使用一阶自回归动态模型预测目标状态,观测模型自适应加权融合的4种互补性特征。实验结果表明,与没有粒子滤波和多特征融合的跟踪算法相比,在相同精确率水平上,该算法的召回率提高20%以上。     

动态多行人环境中基于最优交互避碰的机器人导航

在动态的多行人环境中,服务机器人仅依赖于自身传感器、以第一人称视角自主导航时. 机器人自主定位的不确定性以及对周围行人运动状态估计的不确定性均增加,这给机器人导航决策带来了困难. 为解决这个问题,提出一种基于最优交互避碰的机器人自主导航法. 本方法采用一种改进的粒子PHD滤波法即NP-PHDF法跟踪多个行人的状态. NP-PHDF法结合了卡尔曼粒子滤波及PHD滤波优点,因此它可以跟踪数目变化的多个目标,能够跟踪突然的加减速以及急转弯运动,并且能够抵抗遮挡. 同时,与基于粒子滤波的机器人自主定位法类似,NP-PHDF法使得行人运动状态的不确定性能够以粒子的分布来度量. 为降低状态估计的不确定性,本文提出一种“圈粒子”的粒子圈存法从粒子的分布中提取机器人和行人的真实状态. 算法的有效性在实际场景实验中得到了验证.     

采用EM算法对粒子滤波跟踪算法进行改进

提出了一种改进粒子滤波跟踪算法EMPF(expectation-maximization particle filter)。针对传统粒子滤波存在的动态模型的不确定问题,将EM算法与粒子滤波算法有效结合,将运动模型的参数作为待估量,采用EM算法来确定目标的运动模型参数,从而获得对目标状态的较准确估计。实验结果表明,当目标做复杂的转弯运动时,该算法能够显著地提高对目标运动状态的预测精度。     

基于混合跟踪模型的室内步行人体3D运动估计

针对步行人体3D运动估计过程中的自遮挡问题, 提出了基于混合跟踪模型的粒子滤波算法. 首先, 利用自遮挡状态检测模型, 将步行人体运动划分为四种自遮挡状态; 其次, 根据混合跟踪模型, 针对不同的自遮挡状态, 算法采用不同的跟踪模型; 最后, 为了估计遮挡状态下的人体运动, 算法提出了基于M-估计的在线训练方法 以训练肢体运动相关系数. 经过实验分析, 算法对处 于自遮挡状态下的人体3D运动估计有着良好的效果, 人体3D运动的估计精度得到了提高.     

基于粒子滤波的双模图像融合自适应跟踪

针对视频跟踪中仅利用目标的单特征容易导致跟踪失败的问题,提出一种基于粒子滤波的可见光与红外序列图像相融合的自适应目标跟踪算法;该算法在粒子滤波跟踪算法框架下,根据单一信源运动目标序列图像的品质因子,利用自适应加权融合策略重构双模序列图像的特征选择机制,建立了基于自适应融合算法的系统观测概率模型和状态空间层次采样多特征融合跟踪算法,实现了对双模序列图像的融合以及对运动目标的稳健跟踪;跟踪试验结果表明,该算法可以有效实现对运动目标的稳健、准确跟踪。     

基于t-分布粒子滤波器的目标跟踪

针对贝叶斯跟踪中目标状态的预测分布和后验分布，利用序列蒙特卡洛方法，基于多变量t-分布提出了一种新的粒子滤波算法，称之为t-分布粒子滤波器．为了根据样本估计目标状态的概率分布，提出了一种新的ECME算法，并嵌入到t-分布粒子滤波器中．理论分析表明，在t-分布条件下，t-分布粒子滤波器是在样本数量上的渐近最优估计器．在机动目标跟踪实验中，比较了t-分布粒子滤波器、无色卡尔曼滤波(Unscented Kalman filter)及自助式粒子滤波器(Bootstrap particle filters)的跟踪精度．     

基于灰色系统理论和粒子滤波器的目标跟踪算法

提出一种基于灰色系统理论和粒子滤波的目标跟踪算法,自适应调整搜索范围,并采用交叉熵理论来度量目标模型与粒子确定区域特征模型之间的相似度。先用粒子滤波算法对运动目标状态进行估计,确定目标中心位置,利用历史目标位置状态序列,通过灰色系统理论对下一帧目标状态进行预测;然后对重采样后的粒子的位置和粒子的搜索范围进行修正,采用交叉熵理论来衡量目标与粒子确定区域的特征模型之间的相似度。仿真结果表明,相比传统的粒子滤波算法,新算法具有更好的鲁棒性和跟踪精度。     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

View-based model-driven architecture for enhancing maintainability of data access services

In modern service-oriented architectures, database access is done by a special type of services, the so-called data access services (DAS). Though, particularly in data-intensive applications, using and developing DAS are very common today, the link between the DAS and their implementation, e.g. a layer of data access objects (DAOs) encapsulating the database queries, still is not sufficiently elaborated, yet. As a result, as the number of DAS grows, finding the desired DAS for reuse and/or associated documentation can become an impossible task. In this paper we focus on bridging this gap between the DAS and their implementation by presenting a view-based, model-driven data access architecture (VMDA) managing models of the DAS, DAOs and database queries in a queryable manner. Our models support tailored views of different stakeholders and are scalable with all types of DAS implementations. In this paper we show that our view-based and model driven architecture approach can enhance software development productivity and maintainability by improving DAS documentation. Moreover, our VMDA opens a wide range of applications such as evaluating DAS usage for DAS performance optimization. Furthermore, we provide tool support and illustrate the applicability of our VMDA in a large-scale case study. Finally, we quantitatively prove that our approach performs with acceptable response times.     

A pragmatic multi-method investigation of discrepant technological events: Coping,attributions, and ‘accidental’ learning

Discrepant technological events or situations that entail a problem, a misunderstanding or a difficulty with the Information Technology (IT) being employed, are common in the workplace, and can lead to frustration and avoidance behaviors. Little is known, however, about how individuals cope with these events. This paper examines these events by using a multi-method pragmatic approach informed by coping theory. The results of two studies – a critical incident study and an experiment – serve to build and test, respectively, a theoretical model that posits that individuals use a variety of strategies when dealing with these events: they experience negative emotions, make external attributions, and adopt engagement coping strategies directed at solving the event, eventually switching to a disengagement coping strategy when they feel they have no control over the situation. Furthermore, users’ efforts may result in ‘accidental’ learning as they try to overcome the discrepant IT events through engagement coping. The paper ends with a discussion of the results in light of existing literature, future opportunities for research, and implications for practice.