基于形态成分分析和Contourlet变换的自适应阈值图像去噪方法

针对含有丰富纹理和边缘特征的噪声图像,提出一种基于形态成分分析(MCA)和Contourlet变换的自适应阈值图像去噪方法.该方法首先引入MCA将噪声图像分为低频部分和高频部分,在此基础上设计一种自适应的分层阈值估计处理策略.根据噪声的分布特性,通过阈值估计和Contourlet变换对噪声图像的低频部分和高频部分进行分频带去噪处理,有效去除噪声图像中的噪声.通过对噪声图像的仿真实验表明,文中方法能较好地保留图像纹理和边缘,并且去噪效果优于传统的均值滤波去噪、中值滤波去噪、小波多层阈值去噪和轮廓波多层阈值去噪方法.     

基于NSCT域邻域收缩的SAR图像去噪

针对合成孔径雷达（Synthetic Aperture Radar,SAR）图像受到相干斑噪声的干扰,严重影响了SAR图像的后续处理的问题,提出一种在非下采样轮廓变换（Nonsubsampled Contourlet Transform,NSCT）域将中值滤波和邻域收缩法相结合的SAR图像去噪算法。该算法对原始SAR图像进行NSCT分解,得到低频子带和高频子带图像,对低频子带使用中值滤波处理以去除低频子带中的低频噪声,利用NSCT分解系数之间的相关性,使用邻域收缩法对子带图的系数进行收缩,以消除高频子带中的高频噪声。实验证明,该算法与小波域邻域收缩去噪算法和NSCT硬阈值去噪算法相比,在去噪性能和视觉效果方面均有所提高,在消除噪声同时可以较好地保护纹理细节信息。     

一种PCNN的彩色图像脉冲噪声滤波方法

通过脉冲噪声特性总结以及对脉冲耦合神经网络（PCNN）工作机理的分析,建立了一个在RGB色彩空间上的一种基于脉冲耦合神经网络的彩色图像去噪算法及模型。首先利用PCNN的同步脉冲发放特性定位脉冲噪声点的位置;然后利用中值滤波对其进行去噪处理,并将结果与中值滤波等其他滤波方法进行了比较。实验结果表明该方法不但能够有效去除图像中的噪声,而且能够更好地保护图像细节,较传统彩色图像去噪方法有较明显的优越性。     

基于小波变换的自适应模糊阈值去噪算法

文章提出了一种适合于消除混合噪声的去噪算法——自适应模糊阈值去噪算法。该算法根据信号和噪声的小波系数在不同分解尺度上的传递性,结合中值滤波和模糊理论,自适应地进行软阈值滤波,然后进行小波重构,得到去噪图像。实验表明,与软阈值去噪和改进软阈值去噪算法相比,该算法具有良好而稳健的去噪效果,能够更有效地去除噪声和保持图像边缘细节。     

一种基于小波变换图像去噪的方法

提出了一种基于图像软阈值小波变换的高斯白噪声消除法。该算法根据含噪声图的特点,把信号分成信号象素与可能噪声象素两类,对于可能是噪声的象素,采用图像的小波软阈值去噪方法进行滤波,而对信号象素不产生影响,且能保留更多的图像细节。文中也给出了标准中值滤波,自适应维纳滤波算法和小波软阈值去噪的算法进行比较实验,结果表明用小波软阈值去噪的算法处理高度污染高斯白噪声的图像能力明显强于标准中值滤波,稍微优于自适应维纳滤波算法,且能够比较好保留图像的细节部分。     

一种针对彩色图像随机值脉冲噪声的矢量滤波方法

为了去除彩色图像随机值脉冲噪声,提出了一种新的矢量滤波方法。该方法对图像的平滑区域和边缘区域的滤波工作分开进行,平滑区域滤波方法将窗口分成多个区域,然后基于矢量中值和平滑区域像素的特征检测出平滑区域的信号,边缘区域的滤波是在已知信号的基础上对非信号进行矢量中值滤波。仿真实验结果表明,该方法能够有效地去除彩色图像的随机值脉冲噪声,尤其当噪声密度较高时,去噪效果明显优于传统的矢量中值滤波。     

基于快速离散曲波变换的图像去噪算法

Curvelet变换可以更好地表示曲线奇异函数的异向性及图像边缘,因此更适合于多尺度图像去噪。针对传统阈值法存在的不足,在分析wrapping方法的快速离散曲波变换基础上,提出结合Cycle Spinning循环平移方法的菱形块阈值规则去噪法,并自适应地对不同的Curvelet子块进行阈值化。该方法可以消除由于Curvelet变换缺乏平移不变性而产生的图像失真,并且更好地利用曲波系数的相关性。实验结果表明,该方法与传统的小波去噪、曲波硬阈值去噪、曲波软阈值去噪、曲波软硬阈值折中法去噪相比,使得去噪图像的峰值信噪比更高,视觉效果更好。     

多级块匹配变换域滤波图像去噪

为了进一步提高非局部变换域滤波方法的图像去噪性能,提出一种多级块匹配变换域滤波方法.通过块匹配找到含噪图像中若干相似的图像块,然后执行相似图像块间的一维Haar小波变换,再用硬阈值收缩变换系数实现图像降噪;由于图像中充分相似的图像块数量是有限的,仅用一步上述操作并不能完全去除图像中的噪声,因此通过迭代策略去除剩余的噪声.实验结果表明,无论是PSNR值还是主观视觉质量,该方法的去噪结果都优于块匹配三维滤波方法.     

改进的基于中值滤波和小波变换的图像降噪方法

针对基于小波变换的阈值去噪方法仅适用于去除高斯白噪声,对于脉冲噪声得不到好的降噪效果的问题,提出了将基于高斯模型的小波变换算法与改进的中值滤波相结合的去噪方法。该方法能够有效去除高斯白噪声和脉冲噪声的混合噪声。仿真实验结果表明,结合算法去噪后图像的峰值信噪比和均方误差都比单一算法得到了改善,从而证明了该方法的有效性。     

改进的中值滤波去噪算法应用分析

去噪处理是图像处理中较为重要的环节。中值滤波是抑制图像的噪声的一个行之有效的办法,选择适当大小的中值滤波窗口可以在最大限度地保持图像精度的基础上去除图像噪声。在对中值滤波去噪算法的适用性特点进行研究的基础上,进一步做了中值滤波去噪的改进算法的应用实现研究,同时对其他去噪算法,如均值滤波、低通滤波的小波变换进行实验分析研究,并对实验结果做了相应的比较。     

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.