NUMLS中的多态类型检测

本文从ＮＵＭＬ函数式部分实现中遇到的类型检测问题着手，讨论类型检测问题到半合一问题的转化，给出半合一的转换式求解机制和该转换规则集的可靠性和完备性定理。     

不完备目标信息系统中基于描述子的知识约简

以具有遗漏型未知属性值的不完备目标信息系统为研究对象,根据描述子的定义和基于描述子的粗糙集模型,讨论了知识约简问题.给出了求得描述子所有约简的具体操作方法.根据描述于的支持集与决策类之间的关系,提出了描述子的下、上近似相对约简概念,并给出这两种约简的判定定理及区分函数,为从不完备信息系统中获取简化的决策规则提供了新的理论基础与操作手段.     

多模式下的反合一算法

证明了多模式环境下存在最小反合一,提出了一种反合一算法,并介绍了多模式下反合一的应用.     

SQL查询语言的分治法教学研究

当面对一个较为复杂的查询需求时,学生常感到无从下手,针对这一问题,介绍关系代数完备集到SQL查询语句的转换规则,提出一种构造数据库查询的基于分治算法和局部视图的教学方法,阐述该方法的具体应用过程并说明教学效果.     

SQL查询语言的分治法教学研究

当面对一个较为复杂的查询需求时,学生常感到无从下手,针对这一问题,介绍关系代数完备集到SQL查询语句的转换规则,提出一种构造数据库查询的基于分治算法和局部视图的教学方法,阐述该方法的具体应用过程并说明教学效果.     

带有通配符和长度约束的模式匹配问题求解模型

讨论了带有通配符和长度约束的模式匹配(PMWL)问题,其中模式由子模式序列集组成,两个相邻子模式的间隔在一定长度范围内。针对PMWL问题,已有工作包括设计启发式求解算法和对特殊情况进行完备性分析,然而还需要构建问题的基础求解模型。借鉴约束可满足问题框架,构建了由变量、值域和约束组成的三元组求解模型,对PMWL问题的基本概念和基本性质给出了形式化描述。最后,给出了算法求解PMWL问题的特定条件下的完备解。     

一种求解tableau等式合一问题的算法

在增添扩展规则的tableau方法的基础上提出了一种新的含等词tableau方法——等式合一方法，并证明了它的可靠性和完备性。在该方法中，将tableau分成两个阶段，等词单独处理，通过提取等式合一问题并求解解替换封闭tableau，进一步限制了tableau的搜索空间，提高了tableau的推理效率。同时，为了研究等式合一方法的有效性，在解替换求解方面，提出了提取不等式析取，并在启发式的帮助下计算等价类的方法。通过实例分析，结果表明，等式合一方法优于其它方法。     

布尔逻辑的代数表示及其应用研究

目前布尔逻辑已成为计算机科学的重要理论基础之一,是研究人类思维规律的重要工具.文章提出了一种系统化的布尔逻辑的代数表示方法,其基本思想是把布尔集合用一组多项式来表示,在此基础上定义完备的逻辑运算符集.文章对该方法在可满足性问题(SAT)求解和测试模式自动生成(ATPG)中的应用进行了讨论.     

二维空间中基于约束关系的RNN查询算法

反最近邻(RNN)查询问题是空间数据库中的研究热点问题,但传统算法主要集中在对整个数据集的查询。该文把约束关系的概念引入到了RNN查询中,给出在约束关系下如何利用索引结构进行查询的方法,并根据NN查询和RNN查询问题的内在联系给出相应求解CRNN问题的算法。实验表明该算法比传统算法更能提高查询效率。     

不完备信息系统中的否定决策规则和知识约简

为了从不完备信息系统中获得否定决策规则,提出了描述子否定支撑集的概念,基于此定义了下、上近似集合,讨论其性质,并给出了如何通过该模型获取确定性和可信性否定决策规则的方法．为了便于应用,给出基于分辨矩阵的否定决策规则约简的方法,实例分析的结果表明了该方法的有效性．     

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