一种改进的快速轮廓线提取算法

文章针对传统主动轮廓模型对噪声敏感,初始位置敏感和收敛速度慢等不足,提出了一种基于PSO和GVF的快速轮廓线提取算法。首先利用PSO对轮廓控制点进行寻优,使之快速地收敛到图像的边缘附近;然后利用插值算法,得到目标图像的较粗糙轮廓,以此目标轮廓作为下一步GVF收敛的初始位置,最后得到准确的轮廓线。实验结果表明该算法不仅能对图像轮廓线进行准确的提取,而且具有一定的抗噪性能,易于实现,速度快等特点。     

GVF Snake模型中初始轮廓线设置算法的研究

在详细分析了动态轮廓模型抗干扰性差、运算量大、不能逼近比较复杂轮廓、初始轮廓线设置复杂等问题原因的基础上,提出了轮廓线"有效逼近域"概念,进一步研究发现,这些问题都可以通过设置初始轮廓线到"有效逼近域"内,并有效地控制"有效逼近域"范围而得以解决。由于初始轮廓线只要求设置在"有效逼近域"内,因此符合基于小波变换多尺度边缘检测算法的特性,"有效逼近域"也可以通过控制GVF力场迭代次数来有效控制其大小。基于此,通过采用小波变换多尺度边缘检测获得不同分辨率边缘点,合理控制GVF力场迭代次数,提出初始轮廓线连接算法,成功地实现了初始轮廓线的有效设置。实验结果表明,能够准确地将初始轮廓线设置在"有效逼近域"内,并且"有效逼近域"的大小可以减小到真实轮廓左右5个像素以内,运算量有效的减小,抗干扰性也得到了很大的提高。     

GVF Snake模型中一种新的初始轮廓设置方法

通过对梯度矢量流（GVF）力场迭代和轮廓收敛过程中时间开销大、不能逼近较复杂轮廓等不足之处的分析,提出了一种新的初始轮廓线的设置方法。基于小波变换的多尺度轮廓检测算法,能够较精确地定位出各类轮廓,在此基础上设置的初始轮廓线能够非常好地靠近图像中的各种真实轮廓。实验结果表明,此方法有效地缩小了搜索的范围,减少了GVF迭代次数,提高了轮廓收敛的速度,并保留了GVF Snake模型的所有优点。     

一种改进的GVF模型

在基于snake模型的图像分割中,搜索范围和深度凹陷区域的分割是难点.以往sanke模型的改进多是针对它的外部力场,通过比较改进的传统snake模型--距离snake、GVF和NGVF的优缺点,在不改变力场的情况下,综合它们的优点,提出一个新的模型.先采用距离snake模型使初始轮廓逼近目标物体边缘,然后结合NGVF使收敛进入目标物体的凹陷部分.实验表明该模型具有较大的捕获区且能快速收敛到物体边缘的凹陷部分,提取出感兴趣目标的轮廓.     

图像分割算法在胃溃疡图像上的应用

主要研究了对胃溃疡图像中溃疡轮廓进行精确提取的问题。首先要解决对胃溃疡图像进行图像分割时,复杂多变的背景噪音对分割效果的影响,利用小波变换的多尺度特性对胃溃疡图像进行边缘提取,获得不同尺度下的边缘提取图。通过不同尺度下的边缘效果和溃疡边界的连通性,将不同尺度下获取的边缘再次进行对比和提取,把降低噪音的影响和保持边界连续性有效的统一起来,得到效果更佳的边缘提取图。同时利用梯度矢量流模型将轮廓收敛至溃疡的边界上,并对轮廓内的面积进行计算得到溃疡的面积。计算结果显示,利用小波变换和梯度矢量流模型后得到的溃疡面积,已经能够达到临床医学的要求。     

结合无下采样Shearlet变换和改进尺度积的边缘提取

为了解决遥感图像边缘提取中的伪边缘现象,提出了一种基于无下采样Shearlet变换模极大值和改进数学形态学的边缘提取算法。首先,通过无下采样Shearlet变换对目标遥感图像提取高频分量和低频分量;针对小尺度边缘系数受噪声影响过大,对相邻2个尺度较大的高频系数进行改进,得到尺度多方向的高频系数。然后,采用非模极大值抑制方法对高频系数进行处理,提取高频分量的目标边缘;采用改进的数学形态学方法对低频分量进行处理提取低频目标边缘。最后,将高低频边缘提取结果加权融合,并使用区域连通法去除孤立噪声点,得到最终边缘提取结果。实验表明,与Canny算法、基于NSCT模极大值+Canny算法、基于NSCT模极大值+数字形态学3种算法相比,该算法提取的目标边缘轮廓不仅完整清晰,连续性好,还具有较强的抗噪性。     

基于小波变换模局部极大点原理的车辆轮廓提取

本文根据Mallat小波理论中的图像边缘的对应于小波变换模的局部极大值点,应用小波变换的方法,取得结构元素探测局部极大值点,并用提出的卷包裹算法成功地抽取车辆轮廓。     

基于Canny改进的边缘检测算法

Canny算子受噪声干扰严重,检测噪声污染的图像边缘的效果较差。轮廓结构元素形态学变换能有效滤除图像噪声,同时能保持图像边缘细节。本算法先用轮廓结构元素形态学变换的方法抑制噪声,求取图像梯度并用非极大值抑制法求其局部模极大值,采用双阀值法二值化图像边缘并进行连接。实验表明,该算法能精确提取噪声图像边缘。     

一种基于图割与GVF Snake的凹型目标快速提取算法

将图割理论与GVF Snake模型有机结合,提出了一种凹型目标的快速提取算法。首先用图割算法对初始轮廓线迭代变形,使其在快速提取非凹型段目标边界的同时将轮廓线有效地置于梯度矢量流力场的“有效逼近域”内,然后用GVF Snake算法继续对轮廓线迭代变形,提取凹型段目标边界。实验表明,该算法能快速、准确提取凹型目标。     

基于小波变换的含噪人耳图像边缘检测

为了取得含噪人耳图像的理想边缘轮廓,以实现人耳识别技术的进一步应用,对小波变换边缘检测方法进行了研究,分析了噪声消除与小波变换尺度之间的关系,详细论述了模局部极大值提取边缘的原理.针对含噪人耳图像的特殊性,阐述了一般去噪和边缘检测方法的不足,并针对这些不足提出了改进方法,首先利用样条小波多尺度分解后,相邻尺度小波系数相乘得到尺度积,然后进一步求得尺度积的模和相角,通过自适应阈值去噪提取图像边缘,取得了较好效果.     

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     

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.     

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。