基于核方法的XML文档自动分类

支持向量机(SVM)方法通过核函数进行空间映射并构造最优分类超平面解决分类器的构造问题,该方法在文本自动分类应用中具有明显优势.XML 文档是文本内容信息与结构信息的综合体,作为一种新的数据形式,成为当前的研究热点.文中以结构链接向量模型为基础,研究了基于支持向量机的XML文档自动分类方法,提出了适合XML文档分类的核...     

基于结构与文本关键词相关度的XML网页分类研究

针对XML网页特点，提出了计算XML文档结构相似性、文档关键词出现的位置以及关键词频度的方法，根据计算的结果提取XML网页特征，同时设计了一种基于支持向量机的XML网页多类分类算法．算法通过XML文档的训练样本集为每一类文档建立基于相似公共特征的聚类核，计算测试样本中的文档与每个聚类核的相似度，判断该文档的所属类．实验证明该分类算法具有比较高的分类查全率和查准率，能够较好地解决XML文档同时属于多个类的问题．     

一种新的最小二乘支持向量机算法

基于核方法的学习算法在机器学习领域占有很重要的地位（如支持向量机support vector machines,简称SVM）。但该方法在处理回归问题时的计算复杂度为数据量的立方级。最小二乘支持向量机(least squares support vector machines 简称LS-SVM)在计算复杂性方面对传统的支持向量机的作了很大改进,但是它的计算量也达到样本点数目的平方级。在处理海量数据回归问题时,求解LS-SVM占用大量的CPU和内存资源。本文提出了一种带非齐次多项式核的最小二乘支持向量机算法,由于特征向量中含有常数分量,所以本文去掉了模型中的偏差因子,简化了LS-SVM的回归模型。新方法特别适合于海量数据回归问题。实验显示新方法的求解速度比传统LS-SVM要快很多,同时新方法的准确性却丝毫不亚于LS-SVM     

基于支持向量机的大样本回归算法比较研究

支持向量机的研究是当前人工智能领域的研究热点。基于支持向量机的大样本回归问题一直是一个非常具有挑战性的课题。最近,基于递归最小二乘算法,Engel等人提出了核递归最小二乘算法。文中基于块增量学习和逆学习过程,提出了自适应迭代回归算法。为了说明两种方法的性能,论文在训练速度、精度和支持向量数量等方面,对它们做了比较。模拟结果表明:核递归最小二乘算法所得到的支持向量个数比自适应迭代回归算法少,而训练时间比自适应迭代回归算法的训练时间长,训练和测试精度也比自适应迭代回归算法差。     

回归支持向量机的改进序列最小优化学习算法

支持向量机(support vector machine,简称SVM)是一种基于结构风险最小化原理的学习技术,也是一种新的具有很好泛化性能的回归方法,提出了实现回归支持向量机的一种改进的SMO(sequential minimal optimization)算法,给出了两变量子优化问题的解析解,设计了新的工作集选择方法和停止条件,仿真实例说明,所提出的SMO算法比原始SMO算法具有更快的运算速度.     

基于TreeMiner算法的XML文档结构相似度量方法*

提出了一种基于TreeMiner算法挖掘频繁子树的文档结构相似度量方法,解决了传统的距离编辑法计算代价高而路径匹配法无法处理重复标签的问题。该方法架构了一个新的检索模型—频繁结构向量模型,给出了文档的结构向量表示和权重函数,构造了XML文档结构相似度量计算公式;同时从数据结构和挖掘程序上对TreeMiner 算法进行了改进,使其更适合大文档数据集的结构挖掘。实验结果表明,该方法具有很高的计算精度和准确率。     

一种启式XML结构重构算法

基于海量XML文档查询时信息关联和服务请求多样性的需求,提出一个重构XML结构的频繁向量选择增量模式树(XFP-tree)算法.该算法以XML键为基础,利用向量矩阵处理方法、投影频繁模式树实现XML结构的分裂、合并、更改与取消等操作,同时讨论XML键向量矩阵频繁项集的划分规则及相应启发式策略与支持度阈值.对比其他关联算法,一系列仿真实验表明所提出算法具有一定的有效性及合理性,是重构XML结构的一种有效尝试.     

基于支持向量机分类的回归方法

支持向量机(support vector machine,简称SVM)是一种基于结构风险最小化原理的分类技术,也是一种新的具有很好泛化性能的回归方法.提出了一种将回归问题转化为分类问题的新思想.这种方法具有一定的理论依据,与SVM回归算法相比,其优化问题几何意义清楚明确.     

多尺度核方法的自适应序列学习及应用

多尺度核方法是当前核机器学习领域的一个热点。通常多尺度核的学习在多核处理时存在诸如多核平均组合、迭代学习时间长、经验选择合成系数等弊端。文中基于核目标度量规则,提出一种多尺度核方法的自适应序列学习算法,实现多核加权系数的自动快速求取。实验表明,该方法在回归精度、分类正确率方面比单核支持向量机方法结果更优,函数拟合与分类稳定性更强,证明该算法具有普遍适用性。     

一种启发式XML结构重构算法

基于海量XML文档查询时信息关联和服务请求多样性的需求,提出一个重构XML结构的频繁向量选择增量模式树(XFP-tree)算法。该算法以XML键为基础,利用向量矩阵处理方法、投影频繁模式树实现XML结构的分裂、合并、更改与取消等操作,同时讨论XML键向量矩阵频繁项集的划分规则及相应启发式策略与支持度阈值。对比其他关联算法,一系列仿真实验表明所提出算法具有一定的有效性及合理性,是重构XML结构的一种有效尝试。     

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.     

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.     

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.     

The Distributed Time-Triggered Simulation Scheme: Core Principles and Supporting Execution Engine

Distributed real-time simulation is a young technology field but its practice is under increasing demands. In recent years the author and his collaborators have been establishing a new approach called the distributed time-triggered simulation (DTS) scheme which is conceptually simple and easy to use but widely applicable. The concept was initiated in the course of developing a new-generation object-oriented real-time programming scheme called the time-triggered message-triggered object (TMO) programming scheme. Some fundamental issues inherent in distributed real-time simulation that were learned during recent experimental studies are discussed along with some approaches for resolving the issues. An execution engine developed to support both the TMOs engaged in control computation and the TMOs engaged in DTS is also discussed along with its possible extensions that will enable significantly larger-scale DTSs.     

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。     

Software-Konfigurationsmanagement in großen Softwareprojekten

Zusammenfassung Mit zunehmender Größe der Softwaresysteme verschärfen sich die für die Software-Herstellung typischen Probleme: Beherrschen großer Objektmengen, Erhalten der Systemkonsistenz, Kontrolle der ständigen Änderungseinflüsse und Gewährleisten einer langen Lebensdauer. Die Disziplin Konfigurationsmanagement bildet den methodischen Ansatz, diese Probleme besser zu beherrschen. Software-Konfigurationsmanagement faßt die Herstellung von Softwaresystemen als eine Abfolge von kontrollierten Änderungen an gesicherten Zwischen- und Endergebnissen auf. Dargestellt werden die Objekte und Funktionen des Software-Konfigurationsmanagements sowie die hierfür in großen Software-Projekten benötigten Methoden, Instanzen und Hilfsmittel.