基于密度和层次的快速聚类算法在数据挖掘中的设计及实现

本论文在对各种算法深入分析的基础上,尤其在对基于密度的聚类算法he基于层次的聚类算法深入研究的基础上,提出了一种全新的基于密度和层次的快速聚类算法。该算法保持了基于密度聚类算法发现任意形状簇的优点,而且具有近似线性的时间复杂性,因此该算法适合对大规模数据的挖掘。理论分析和实验结果也证明了基于密度和层次的聚类算法具有处理任意形状簇的聚类、对噪音数据不敏感的特点,并且其执行效率明显高于传统的DBSCAN算法。     

SUDBC:一种基于空间单元密度的快速聚类算法

随着数据规模越来越大,要求聚类算法有很高的执行效率,很好的扩展性,能发现任意形状的聚类以及对噪音数据的不敏感性.提出了一种基于空间单元密度的快速聚类算法SUDBC,该算法首先将被聚类的数据划分成若干个空间单元,然后基于空间单元密度将密度超过给定阈值的邻居单元合并为一个类.实验结果验证了SUDBC算法具有处理任意形状的数据和对噪音数据不敏感的特点.     

一种改进的基于密度的聚类算法

基于密度的聚类是聚类算法中的一种,其主要优点是可以发现任意形状的簇,对噪声不敏感.而现有的该类算法对于空间数据分布不均匀的情况聚类效果不佳.鉴于此,文中提出一种改进的基于密度的聚类算法,保持了基于密度的聚类算法的优点,并且可以有效地处理分布不均的数据集,减少了时间复杂度,适用于对大规模数据库的挖掘与分析.     

一种改进的基于密度的聚类算法

基于密度的聚类是聚类算法中的一种，其主要优点是可以发现任意形状的簇，对噪声不敏感。而现有的该类算法对于空间数据分布不均匀的情况聚类效果不佳。鉴于此，文中提出一种改进的基于密度的聚类算法，保持了基于密度的聚类算法的优点，并且可以有效地处理分布不均的数据集，减少了时间复杂度，适用于对大规模数据库的挖掘与分析。     

一种基于网格密度的自适应聚类分析算法*

在结合基于密度和基于网格的聚类算法优点的基础上,提出一种新的聚类算法.该算法能够在海量、高纬数据下发现任意形状的聚类并对噪声数据不敏感,具有较低的时间和空间复杂性及较高的识别率.通过实验对该算法进行了性能比较和测试,显示了它在各方面的优越性.     

基于密度的空间聚类算法研究

基于密度的聚类算法作为数据挖掘方法中的一种主要方法,不仅可以从数据集中发现任意形状的簇,而且可以观察到一个并发的、完整的聚类结构,以及具有对噪声数据不敏感的特点.针对目前常用的几种基于密度的聚类算法及改进算法进行讨论,分析了这些密度聚类算法各自的优缺点,并且以地理信息系统为应用研究背景,提出了基于密度的聚类算法与GIS相结合,通过对多维数据属性特征的提取,扩展到多维数据的处理,在三维空间地形数据中的分析中取得了高效的聚类结果.     

一种改进的基于密度的聚类算法

基于密度的聚类是聚类算法中的一种,其主要优点是可以发现任意形状的簇,但处理大数据集时效果不佳,为此提出了一种改进的算法M-DBSCAN,保留了基于密度聚类算法的优点,同时克服了以往算法不能处理大数据集的缺点。实验结果证明,M-DBSCAN聚类算法在聚类质量及速度上都比原DBSCAN有较大提高。     

基于密度的空间聚类算法研究

基于密度的聚类算法作为数据挖掘方法中的一种主要方法,不仅可以从数据集中发现任意形状的簇,而且可以观察到一个并发的、完整的聚类结构,以及具有对噪声数据不敏感的特点。针对目前常用的几种基于密度的聚类算法及改进算法进行讨论,分析了这些密度聚类算法各自的优缺点,并且以地理信息系统为应用研究背景,提出了基于密度的聚类算法与GIS相结合,通过对多维数据属性特征的提取,扩展到多维数据的处理,在三维空间地形数据中的分析中取得了高效的聚类结果。     

基于密度的最小生成树聚类算法研究

基于密度的方法是一种相当有效的聚类方法,能够发现任意形状的聚类,对噪声数据不敏感,但是聚类结果严重依赖于用户参数的合理选择。针对其存在的问题,将最小生成树理论与基于密度的方法相结合,提出了一种基于密度的最小生成树聚类算法。通过构造、分割最小生成树得到确定样本空间划分的最小生成子树;根据子树特性,产生局部密度参数;并对生成子树进行局部密度聚类。理论分析和应用结果表明。该算法不仅体现了基于密度聚类方法的优点,聚类结果不依赖于用户参数的选择,使数据聚类更合理,特别是对大型数据库非常有效;也体现了数据分区的思想,使其可以并行执行,进一步提高了信息处理的时空效率和性能。     

快速DOC算法及其学生成绩分析中的应用研究

针对现有基于密度聚类算法在簇扩展方法上的优势及其聚类判据的弊端,提出了一种融入启发式思想的基于密度的DOC算法。启发式DOC算法通过降低扫描数据的个数,加快DOC算法的运行速度。实验表明,算法在聚类精度、执行效率方面具有一定的优越性,能够发现任意形状分布的数据。     

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.     

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.     

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.     

Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and     

Editorial:Brain-machine interface(BMI) and cyborg intelligence

正Brain-machine interfaces(BMIs)aim at building a direct communication pathway between the brain and an external device,and represent an area of research where significant progress has been made during the past decade.Based on BMIs,mind information can be read out by neural signals to control     

Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and overseas to the world’s scientific circles,especially to stimulate     

SCIENCE CHINA Information Sciences SUBJECT INDEX TO VOLUME 57(2014)

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Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and overseas to the world’s scientific circles,especially to stimulate