模糊环境下的Web用户浏览模式的挖掘

提出加权支持度和加权偏爱度用来准确反映用户的访问兴趣.其中,专家给定网页的语言评估被刻画成相应的模糊语言变量,使用模糊模拟的方法把这些模糊语言变量转化成表示网页重要性的权重.为了避免用户重要浏览信息的丢失,建立包含所有用户浏览信息的频繁链表加存权树(FLAAT),并从中挖掘用户偏爱的浏览模式.此外网页上的浏览时间也是反映用户兴趣和偏爱的一个重要因素,它被表示成相应的模糊语言变量,因而所获得的带有模糊浏览时间的用户偏爱浏览路径更能反映用户的兴趣和偏爱.     

基于模糊模拟的加权偏爱浏览模式的挖掘

每个网页由不同的专家给出语义上的重要性评估,这些语义评估再被刻画成相应的模糊语言变量,通过模糊模拟的方法,这些模糊语言变量被转化成表示网页重要性的权重。此外,简单地认为用户的访问频度反映了用户的访问兴趣是不准确的,因此在提出的加权支持度和偏爱度概念的基础上,从建立的包含了所有用户浏览信息的FLaAT(Frequent Link and Access Tree)上,挖掘用户偏爱的加权浏览模式。试验证明该算法是行之有效的。     

基于FLaAT的模糊用户偏爱浏览模式的增量挖掘

挖掘用户偏爱的浏览模式就是从Web日志中发现多数用户偏爱的浏览路径.网页上的浏览时间被转换成一个模糊语言变量来体现网页上浏览时间的特征,最后从建立的包含所有用户浏览信息的FLaAT(Frequent Link and Access Tree)中挖掘增量式带有模糊语言变量的用户偏爱浏览模式.     

从Web日志中挖掘用户浏览偏爱路径

Web日志中包含了大量的用户浏览信息，如何有效地从其中挖掘出用户浏览兴趣模式是一个重要的研究课题．作者在分析目前用户浏览模式挖掘算法存在的问题的基础上，利用提出的支持一偏爱度的概念，设计了网站访问矩阵，并基于这个矩阵提出了用户浏览偏爱路径挖掘算法：先利用Web日志建立以引用网页URL为行、浏览网页URL为列、路径访问频度为元素值的网站访问矩阵．该矩阵为稀疏矩阵，将该矩阵用三元组法来进行表示．然后，通过对该矩阵进行支持一偏爱度计算得到偏爱子路径．最后进行合并生成浏览偏爱路径．实验表明该算法能准确地反映用户浏览兴趣，而且系统可扩展性较好．这可以应用于电子商务网站的站点优化和个性化服务等．     

一种挖掘用户浏览模式的新方法

提出了页面兴趣度的概念,并把它用一个三元组(页面的访问时间,页面的大小,页面访问次数)表示.这个概念准确地反映了用户对页面的访问情况.在此基础上建立了以引用网页URL为行、浏览网页URL为列,页面兴趣度为元素值的网站访问矩阵.通过对该矩阵计算得到用户浏览偏爱路径.实验表明该算法能准确地反映用户浏览兴趣.     

基于Web日志挖掘用户的浏览兴趣路径

提出一种基于Web日志发现用户浏览偏爱路径算法。引入了支持-兴趣度概念。建立用户访问矩阵以表示用户浏览网页行为,并获得访问矩阵的海明距离矩阵。通过对距离矩阵与相似度阈值的计算获得偏爱路径的候选2项子路径,再利用支持-兴趣度对候选集做进一步的过滤,最后进行合并并生产浏览偏爱路径。实验表明该算法可以有效地反映用户的浏览兴趣。     

一个可以准确反映Web 浏览兴趣的度量值——偏爱度

在分析如何准确反映Web浏览兴趣的基础上提出偏爱度的概念，并依据这个概念设计了基于用户浏览偏爱树的偏爱路径挖掘算法，首先用Web日志构筑用户浏览偏爱树(PNT)；然后利用PNT树进行用户浏览兴趣模式的挖掘，发现用户浏览偏爱路径，该算法可广泛应用于电子商务领域。     

基于用户浏览行为分析的用户兴趣度计算

从用户的浏览行为可以反映用户的兴趣出发,分析了用户的浏览行为与兴趣之间的关系,通过分析把能反映用户兴趣的典型浏览行为归纳为保存页面、打印页面、将页面加入收藏夹、复制页面内容、访问同一页面的次数和在页面上浏览时间这些浏览行为.针对这些浏览行为下的用户兴趣度计算做出阐述,并且在分析基于网页驻留时间和浏览次数计算网页兴趣度的算法的基础上,考虑网页大小的影响因素,使用基于浏览速度计算网页兴趣度,同时利用BP神经网络进行用户兴趣度融合.     

一种新的基于Web日志的挖掘用户浏览偏爱路径的方法

提出了一种新的基于Web日志的挖掘用户浏览偏爱路径的方法.该方法首先在单元数组存储结构(存储矩阵)基础上建立以浏览兴趣度为基本元素的会话矩阵和路径矩阵.然后,在会话矩阵上采用两个页面向量夹角余弦作为相似用户的页面距离公式进行页面聚类,求得相似用户的相关页面集.最后,利用路径选择偏爱度在相似用户的路径矩阵上挖掘出相似用户的浏览偏爱路径.实验证明此方法是合理有效的,能够得到更准确的偏爱路径.     

基于Web日志的频繁偏爱路径挖掘算法

为了挖掘出更能如实反映Web用户兴趣偏好的使用模式,充分考虑了用户在页面的停留时间和点击次数两个因素,给出了频繁偏爱路径的定义,并提出了频繁偏爱路径的挖掘算法,该方法在求得最大向前路径的基础上,迭代产生更长的候选频繁偏爱路径,通过计算候选路径的频繁偏爱支持度来判断其是否为频繁偏爱路径.利用真实日志数据进行实验,实验结果表明,该算法具有较高的覆盖率和准确性.     

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.     

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.     

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。