基于边缘前景的混合高斯模型目标检测

混合高斯模型已经广泛应用于背景建模中。但是检测结果受到噪音的干扰和突变光照的影响。为了解决这个问题,将Stauffer的混合高斯模型进行改进并与边缘信息相结合。当三帧差分判断出场景变化时,像素点的学习率会自适应变化。用这种改进的混合高斯模型来获取运动物体的边缘图像和前景图像。对边缘图像进行图像膨胀,再与前景图像进行与运算,通过光流信息来填补空洞部分,得到最后的结果。实验结果表明,可以很好地去除噪音和解决光照突变的影响,提高了目标检测的效果,比传统方法更加有效。     

基于改进的混合高斯模型的目标检测

混合高斯模型已经广泛应用于背景建模中,但是结果受到噪音的干扰和光照突变的影响。为了解决这个问题,将Stauffer的混合高斯模型进行改进,当帧间差分判断出场景变化时,每个像素点的学习率会随着变化。由于边缘图像受到噪音干扰小,将这种改进的混合高斯模型也应用在边缘图像中,来提取边缘前景。边缘前景膨胀后,通过原图像的前景和边缘前景的与运算,得到最后的结果。实验结果表明,可以很好地去除噪音和解决光照突变的影响,提高了目标检测的效果,比传统方法更加有效。     

基于边缘帧差和高斯混合模型的行人目标检测*

针对高斯混合模型存在背景更新收敛性差,易受环境噪声和光照突变影响,易产生虚假目标等问题,提出一种基于高斯混合模型的改进算法,用于视频中行人目标检测。通过将帧差法引入高斯混合模型,快速区分背景区域和运动目标区域,从而提取前景中完整的行人目标。结合视频帧边缘和边缘帧差信息,采用多种模型更新率,提高高斯混合模型对复杂背景的自适应性和快速收敛性,从而消除环境噪声和光照突变的影响,避免检测出虚假目标。实验结果表明,相比较传统高斯混合模型,该方法可以有效去除噪声和光照的干扰,收敛性更佳,行人检测效果更鲁棒。     

基于改进高斯混合模型的运动目标检测方法

传统高斯混合模型(GMM)对于光照突变十分敏感,且收敛速度较慢。为此,提出一种基于改进GMM的运动目标检测方法。利用不匹配像素消除光照影响,使用改进的GMM提取背景图像。通过差分当前帧与背景图像获得二值差分图像,从该差分图像中获取运动目标。实验结果表明,该方法能适应光照变化,提高检测的准确性和鲁棒性。     

光照突变环境下基于高斯混合模型和梯度信息的视频分割

基于高斯混合模型和帧间梯度信息提出了一种新的运动目标分割算法。首先,在利用亮度信息对背景建立自适应高斯混合模型的基础上,进行前景的粗分割;其次,由于视频信号的亮度和色彩分量随光照突变有较大的改变,导致大片背景的高斯模型产生错误匹配,误判为前景,为了提高高斯模型分割算法的鲁棒性,结合结构梯度互相关函数对分割结果进一步校正,能适应剧烈的光照变化;最后,利用数学形态学进行后处理,消除影子和孤立的噪声点。通过不同场景的运动分割实验结果表明,该算法在复杂背景和剧烈光照变化条件下具有较强的鲁棒性和较高的分割精度。     

一种改进的基于混合高斯模型的运动目标检测算法

运动目标检测是实现目标跟踪和行为分析等任务的基础。在运动目标检测中,消除背景与噪声的干扰,从而将运动目标从图像中分离出来一直是研究的重点。混合高斯模型法被广泛地应用于运动目标检测,对存在小幅度运动的背景有较好的抗干扰能力,并且能提取出较完整的运动目标,但是同时存在噪声干扰,且对阴影抑制效果较差。针对传统混合高斯模型法的不足,提出一种改进的基于混合高斯模型的运动目标检测算法,利用帧差法对光照突变适应性较好和算法简单的特点,将传统混合高斯模型法与和四帧差法结合。实验结果表明,该方法能够有效地消除复杂环境中的噪声,并对阴影有一定的抑制作用,提高了运动目标检测的准确性和完整性。     

基于熵理论改进混合高斯模型的运动目标检测算法

针对传统混合高斯模型学习率和背景模型阈值均采用无向导式选取方法,提出了相应的自适应更新策略.学习率自适应更新算法融合图像熵和2-D学习率查找表方法,解决了光照突变时背景更新过慢及固定权值造成的不能兼顾环境适应能力和抗干扰性问题.提出一种类间最大对称交叉熵阈值自适应选取方法,弥补了传统方法在选取背景模型时仅考虑权值而未考虑决定像素点归属问题的均值和方差对分类影响这一缺陷.实验结果表明,与传统算法相比,改进算法在克服光照突变、检测准确率、实时性以及目标提取完整度上均表现良好.     

复杂背景下感兴趣运动目标的跟踪算法

针对由于复杂背景的干扰而导致不能准确跟踪感兴趣运动目标的问题,提出一种基于多特征自适应融合的粒子滤波跟踪算法。首先在HSV颜色空间中得到感兴趣运动目标的加权颜色分布模型,然后利用不变矩特征来消除背景中相似颜色物体和光照变化的干扰,两种特征通过自适应调整权重来更新粒子权值而融合于粒子滤波算法中,从而能够准确和稳定地跟踪运动目标。实验证明,该算法在运动目标平移、姿态变化、遮挡、光照变化及相似颜色干扰等复杂背景下都能够准确地进行跟踪,对背景干扰具有很强的鲁棒性。     

基于改进混合高斯模型的井下目标检测算法

煤矿井下监控视频图像质量差、噪点多、光照易突变,采用传统混合高斯模型进行目标检测存在运行速度慢、算法复杂度高、易受光照影响等问题。针对该问题,提出了一种基于改进混合高斯模型的井下目标检测算法。使用改进的暗通道去雾算法对井下图像进行预处理,对井下雾图的缩略图求暗通道图,并采用双线性插值得到去雾图像;在混合高斯模型的基础上,使用改进的块建模策略降低建模复杂度,提高算法运行速度;结合三帧差分法,根据图像前景所占比例对高斯建模前期和建模后期设定不同的学习率,以抑制光照对目标检测的影响,提高建模速度和准确度。实验结果表明,当光照发生突变时,该算法能较好地描述检测对象,对光照变化有明显抑制作用;与三帧差分法、传统混合高斯模型相比,该算法可有效提高处理速度。     

多特征融合的Camshift算法及其进一步改进

基于颜色核的Camshift算法可以有效实现简单场景下的目标跟踪,但在光线变化明显或目标与背景颜色相近的场景下易受干扰。为此,采用颜色、边缘梯度、纹理等多个特征自适应融合的方式改进算法,提高算法应对光线变化的能力;并通过修正特征直方图、设置合理搜索范围对算法进行进一步改进,解决相似背景的干扰问题。实验结果显示,在光照变化明显或目标与背景特征相近的场景中,改进的算法与传统算法相比具有更高的跟踪精度。     

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。     

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。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.