基于目标跟踪的粒子群粒子滤波算法研究

针对粒子滤波方法在重采样阶段容易造成样本有效性和多样性的损失,导致了样本贫化问题,提出了一种改进的粒子滤波算法.算法将粒子群优化思想引入粒子滤波中,在粒子采样过程前先利用粒子群算法进行优化.粒子群算法将最新观测值融合到粒子进化公式中,大部分粒子经过粒子群优化后,朝着后验概率分布比较密集的区域运动,聚集在最优粒子附近,使粒子的权值被提高,避免了在重新采样过程中被舍弃,进而缓解了样本被贫化问题.目标跟踪系统中的位置估计由于物体运动具有突然性,很难准确估计.采用非线性目标跟踪模型和分时恒定值模型分别研究改进粒子滤波算法对误差均方值的影响.仿真结果表明改进算法与常规粒子滤波算法和扩展卡曼滤波算法相比,更加有效地降低变量的误差均方值,从而提高了滤波性能.     

一种改进的视频图像检测跟踪算法

针对运动目标在运动过程中的交叉、遮挡等情况,采用自适应阈值的Vibe算法来压缩背景杂波和相关噪声,进而对运动目标进行检测.采用基于Camshift优化的粒子滤波算法对运动目标进行跟踪,该算法在粒子滤波算法的基础上结合Camshift算法的优点,加入当前观测信息,使粒子更好地采样于目标周围,提高了粒子效率,节省了算法时间.实验表明,自适应阈值的Vibe算法能够准确检测复杂场景中的运动目标,并能够适应噪声干扰和光照变化,而基于Camshift优化的粒子滤波算法能够在目标快速运动、遮挡情况下对目标进行准确跟踪.     

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。     

高斯粒子群优化粒子滤波检测前跟踪算法

针对低信噪比时标准粒子滤波对弱小目标的检测与跟踪时存在的粒子贫乏、跟踪精度对粒子数目要求高等问题,提出一种基于高斯粒子群优化粒子滤波的弱小目标检测前跟踪算法。利用高斯粒子群优化算法优化重采样后的粒子集,使粒子集朝着后验概率密度分布取值较大的区域运动,增加粒子的多样性,克服了粒子贫乏问题,并在保证跟踪精度的前提下降低了跟踪所需要的粒子数目,提高了标准粒子滤波算法的检测和跟踪性能。同时,建立了检测前跟踪系统的观测模型和系统模型,对基于标准粒子滤波检测前跟踪算法和优化算法进行仿真,仿真实验结果表明高斯粒子群优化粒子滤波的检测前跟踪算法相比基于标准粒子滤波的检测前跟踪算法具有更好的检测与跟踪性能。     

基于混合粒子滤波的运动火焰跟踪算法

提出一种基于混合粒子滤波的运动火焰跟踪算法。针对通用粒子滤波算法计算量大的问题,提出了混合粒子滤波,将Mean Shift算法嵌入到粒子滤波中,并用自适应运动模型和目标模型自动更新的策略改善算法性能。基于混合粒子滤波提出了火焰识别和火焰跟踪相结合的运动火焰自动跟踪算法,先火焰识别,再火焰跟踪,且跟踪时,如果估计目标与模型的相似度小于阈值则切换到火焰识别阶段。识别与跟踪的相互切换保证了跟踪结果的正确性。实验结果表明混合粒子滤波具有很好的跟踪效果,与粒子滤波和Mean Shift算法相比,提高了跟踪精度;基于混合粒子滤波的火焰跟踪算法能够跟踪复杂环境下的运动火焰,提供火焰的精确位置。     

闪烁噪声下的自适应无迹卡尔曼算法

针对非高斯噪声环境下过程噪声统计特性未知时机动目标跟踪精度不高甚至发散的问题,提出了一种应用EM算法和无迹卡尔曼滤波(Unscented Kalman filter,UKF)相结合的方法。该方法借助EM算法估计出较准确的过程噪声参数,再使用无迹卡尔曼滤波算法获得高精度的目标运动状态。仿真实验结果表明,该方法可以有效抑制滤波发散并显著提高跟踪精度。     

一种有效的体育视频目标跟踪算法

论文研究了面向体育视频的运动目标跟踪技术,提出了一种最优化的混合跟踪方法。首先,采用粒子滤波算法来预测运动目标的初略位置,通过比较预测位置上的目标同目标模型之间的相似度,当相似度小于一定的阀值时,认为目标运动模型发生了根本变化,需要启用新的运动模型;当相似度大于一定的阀值时则认为目标运动模型没有发生大的变化,不需要启用新的运动模型,通过这种方式找到目标的最优化运动模型。最后将最优化的运动模型用于基于核的均值转移算法中,从而获得运动目标的精确位置。     

一种改进的基于Camshift的粒子滤波实时目标跟踪算法

为了能够快速和准确地跟踪运动目标,提出了一种改进的基于Camshift的粒子滤波算法。在粒子滤波框架下,首先对传统目标模型进行改进,提出一种新的融合目标颜色信息和运动信息的模型,以增强目标跟踪的稳健性和准确性;同时为了提高跟踪的效率,将一种改进的Camshift算法嵌入到粒子滤波中,用来重新分配随机粒子样本,使之向目标状态的最大后验概率密度方向移动。实验结果表明,与传统的粒子滤波算法或Camshift算法相比,该方法能有效处理目标快速运动或背景存在强干扰等情况,实现对目标快速和稳健的跟踪。     

基于自适应表面模型的概率视频跟踪算法

提出一种鲁棒自适应表面模型,该模型中每个像素值的变化过程由一混合高斯分布描述．为了适应目标表面的变化,这些高斯参数在跟踪期间通过在线的EM算法自适应更新;在估计目标状态时。采用了粒子滤波算法。设计了基于自适应表面模型的观测模型;在处理遮挡时,采用了一种鲁棒估计技术．多组试验结果表明,该算法对光照变化、姿态变化、部分或完全遮挡下的跟踪具有较强的鲁棒性．     

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。     

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。     

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.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

基于QTE的蒙古文显示机制研究与实现

蒙古语言是中国蒙古族使用的通用语言,由于蒙古文区别于其他文字的书写方式和其自身变形机制等特点,在很多通用的文字处理引擎中都不被支持。在嵌入式产品开发与应用领域中Linux加QTE已经成为流行方式。该文给出了一种在QTE环境上实现基于标准Unicode的蒙古文点阵显示和变形算法, 并自定义了支持蒙古文的QTE组件,扩展了QTE功能,为在Linux加QTE方式的嵌入式体系结构中处理蒙古文提供了一种解决方法。