多粒度时间文本数据的周期模式挖掘算法

大规模文本数据挖掘是大数据分析的重要分支,也是近年来的一个研究热点。研究了多粒度时间文本数据周期模式挖掘算法,首先提出了时间粒度转换、多粒度时间间隔等概念,然后建立了文本数据的周期模型,给出了一个多粒度时间文本下的周期模式挖掘算法,最后对大量病毒文本文献数据进行了实验,表明了提出的算法可以挖掘一些有效的周期模式,讨论了周期宽松度对支持度和置信度的影响。该研究为大文本数据分析提供了一种新的方法。     

一类多粒度近似周期关联规则问题的挖掘研究

研究一类在多粒度时间下单事件同属性不同状态之间有一定关联的近似周期规律挖掘问题。给出了多粒度近似周期关联规则模型形式化的数学定义和性质，构造了相关模型，提出了利用聚类算法挖掘周期模式并应用于股票数据进行实验，实验结果表明算法是有效的。     

多粒度时间部分周期模型

时间的描述和划分是时态数据采掘中一个非常重要的方面,针对目前时态数据采掘中缺少对多粒度时间等的研究的现状,提出了多粒度时间,粒度转换,时态序等的严格数学定义,并研究和证明了它们的相关性质.以此为基础引出了一个多粒度时间部分周期模型,对模型的支持度和置信度等性质进行了详细讨论,并将多粒度时间下的部分周期模型运用到股票数据实验中,实验表明所提出的模型对于研究时态数据采掘具有重要意义.     

基于多尺度的时序数据部分周期模式增量挖掘

针对动态时序数据部分周期模式挖掘过程存在的计算复杂度过高和扩展性差等问题,提出了一种结合多尺度理论的时间序列部分周期模式挖掘算法（MSI-PPPGrowth）,所提算法充分利用了时序数据客观存在的时间多尺度特性,将多尺度理论引入时序数据的部分周期模式挖掘过程。首先,将尺度划分后的原始数据以及增量时序数据作为更细粒度的基准尺度数据集进行独立挖掘;然后,利用不同尺度数据间的相关性实现尺度转换,以间接获取动态更新后的数据集对应的全局频繁模式,从而避免了原始数据集的重复扫描和树结构的不断调整。其中,基于克里金法并考虑时序周期性设计了一个新的频繁缺失计数估计模型（PJK-EstimateCount）,以有效估计在尺度转换过程中的缺失项支持度计数。实验结果表明,MSI-PPPGrowth具有良好的可扩展性和实时性,尤其是对于稠密数据集,其性能优势更为突出。     

多粒度时间下的近似周期挖掘研究

研究时态数据库中多粒度时间下的近似周期的挖掘问题。在多粒度时间、多粒度时问格式的基础上引入多粒度时间间隔的定义以及相关性质,构造多粒度近似周期模型,提出一个基于SOM聚类的多粒度近似周期的挖掘算法。利用高频股票数据580000宝钢JBT1进行实验,证明了该算法的有效性。     

多粒度时间下的近似周期挖掘研究

研究时态数据库中多粒度时间下的近似周期的挖掘问题。在多粒度时间、多粒度时间格式的基础上引入多粒度时间间隔的定义以及相关性质,构造多粒度近似周期模型,提出一个基于SOM聚类的多粒度近似周期的挖掘算法。利用高频股票数据580000宝钢JBT1进行实验,证明了该算法的有效性。     

直觉模糊关联规则挖掘及算法研究

针对关联规则挖掘中连续属性离散化时的"尖锐边界"问题,提出了一种用直觉模糊集合理论来改进关联规则挖掘的方法,定义了直觉模糊非支持度和非置信度的概念,阐述了"支持度-非支持度-置信度-非置信度"的关联规则挖掘度量机制.描述了直觉模糊关联规则挖掘的基本原理和算法,并给出了算法的基本步骤,最后用实例验证了此算法的有效性.     

基于FPclose算法挖掘强亲密度关联模式

基于FPclose算法提出了一种挖掘强亲密度关联模式的算法。算法引入客观兴趣度度量h-置信度来识别强亲密度关联模式,利用其反单调性质和交叉支持度性质进行剪枝。实验证明,该算法能够高效地挖掘出倾斜数据集中的强亲密度关联模式。     

基于时序和兴趣度约束的加权关联规则挖掘算法研究

为了解决关联规则挖掘算法中频繁集信息挖掘不完善和时序周期对事务集频繁项挖掘的影响问题,提出了一种基于时序和兴趣度约束的加权关系规则挖掘算法。该算法首先利用时序滑动函数对时序事务集进行发生概率估算和权值赋值,依据兴趣度约束函数和剪枝定理进行事务集化简,然后根据支持度和寿支持期望进行加权频繁事务集抽取,最后依据置信度进行加权关联规则导出。实验结果证明,该算法能够快速有效地挖掘出符合用户兴趣度的关联规则。     

多支持度下用户行为序列模式挖掘方法研究

针对现有用户行为序列模式挖掘方法的单一支持度局限性问题,提出一种基于前缀树结构的多支持度序列模式挖掘方法。设计一种多支持度条件下的前缀树结构MSLP-tree,并基于此结构提出一种序列模式增长算法MSLP-growth。通过考虑各数据项不同最小支持度,获取更精确的频繁序列模式,在确保挖掘结果的准确性和完整性的前提下,大大压缩搜索空间,缩短挖掘时间。实验结果表明,相较于MS-GSP算法,MSLP-growth算法具有更高的挖掘效率和可扩展性。     

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.     

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