构造代数Blending曲面的Grobner基方法

利用代数几何中关于理想的Groebner基的理论，结合CAGD中的研究方法，对代数Blending曲面做了较为细致的研究，给出了用Groebner基构造代数Blending曲面的新方法，该方法能够求出所有满足要求的代数Blending曲面，并能给出其中次数最低的曲面，文中还讨论了如何利用代数曲面插值，最小平方逼近的方法来选取合适的自由参数，以达到对代数Blending曲面进行形状控制的目的，最后给出了一个茶壶表面造型示例，以说明方法的有效性。     

基于多项式符号代数方法的高层次数据通路的等价验证

基于BDD或布尔SAT的等价验证方法虽然能够成功验证低层次门级电路,但却难以满足高层次设计验证要求.由此,以多项式符号代数为理论基础,提出了一个高层次数据通路的等价验证算法.深入研究了使用多项式表达式描述复杂数据通路行为的方法,得到了高层次数据通路的多项式集合表示的一般形式.从多项式集合公共零点的角度定义了高层次数据通路的功能等价,给出了一个基于Gr(o)bner基计算的有效代数求解算法.针对不同基准数据通路的实验结果表明了该算法的有效性.     

基于Grobner基的对称正交多带多维滤波器组设计

通过引入计算代数中Gr(o)bner基技术和合冲模算法,提出了一种多带多维滤波器组的多相元矩阵的对称正交化设计方法,给出了一个4带二维对称正交滤波器组的设计算例;另外,给出了由多维滤波器组构造多维小波的多维尺度方程表示形式,并将设计得到的4带二维滤波器组构造出一种4带二维小波.     

基于Grbner基的对称正交多带多维滤波器组设计*

通过引入计算代数中Grbner基技术和合冲模算法,提出了一种多带多维滤波器组的多相元矩阵的对称正交化设计方法,给出了一个4带二维对称正交滤波器组的设计算例;另外,给出了由多维滤波器组构造多维小波的多维尺度方程表示形式,并将设计得到的4带二维滤波器组构造出一种4带二维小波。     

基于ZBDD的布尔多项式Grbner基算法的实现

零压缩二元判定树ZBDD(Zero-suppressed Binary Decision Diagrams)作为一种近年来兴起的存储布尔多项式的数据结构能更有效地平衡内存消耗与计算速度;基于它的布尔多项式Grbner基算法可以在运算中保持ZBDD结构的不变性从而进一步提高计算效率。用C++实现了布尔多项式的Grbner基计算并对其进行既约化处理,验证了该算法的可行性以及在运算效率上的提高。     

字典序下BMS算法终止条件的设计

编码理论中的BMS算法具有良好的解码效率与纠错能力,目前的研究通常集中于分次项序下的情形。通过分析字典序与分次项序的本质特征,利用与BMS算法密切相关的Gr?bner基的消去性质,设计出字典序下BMS算法的终止条件,并给出了基于该条件的易于实现的具体算法描述。实验结果表明,该终止条件切实有效,与算法中的原始理论终止条件完全吻合。     

关键方程的新推广

给出了关键方程的全新的推广,构造了一个齐次关键模方程,并用域F上的两个变元的多项式环F[x,y]的齐次理想刻画该方程的解空间;证明了齐次关键模方程可以用来解决卷积码的盲识别问题,这是一个全新的研究课题,在智能通信、信息截获和密码分析等领域有重要的应用;利用该方法得到的二元多项式齐次理想Gr（o）bner基的快速算法,给出了求解齐次关键模方程的快速算法,也给出了详细的计算实例.大量的实验也证实了该文的各项理论分析结果.     

基于广义代数旋转曲面的刚柔混合人体几何建模方法

为了满足计算机辅助人机工程应用软件对数字化人体模型外观逼真性及运动真实性的要求,提出采用广义代数旋转曲面进行刚、柔混合人体几何建模的方法.首先在拓宽传统代数旋转曲面的基础上,提出广义代数旋转曲面并给出曲面隐式方程组的表达方式;其次利用广义代数旋转曲面对人体肢体表面进行几何统一表示,并将主躯干(腰部和胸部)在姿态变换过程中视为柔性肢体;最后,通过应用实例表明了人体模型的有效性,并能较好地满足人机仿真的需要.     

隐式磨光曲面的保凸性研究

对隐式代数磨光曲面的保凸性进行了研究。证明了如果两个隐式代数曲面是凸的,则它们光滑拼接后,得到的磨光曲面在一定条件下仍然是凸的。以凸三面角为例,提出了利用代数样条磨光的方法并证明了利用这种磨光方法得到的磨光曲面具有保凸性。     

有理Bézier曲面的区间隐式化

本文依据以往的研究引入了有理Bézier曲面的区间隐式化的概念,即找到一条较低次的区间代数曲面使得给出的有理Bézier曲面落在该区间代数曲面内,并使得该区间代数曲面的宽度达到最小.文中给出了一个通过解一个带有线性限制条件的二次优化问题来计算一有理Bézier曲面的区间代数曲面的算法,并用实例演示了该算法.     

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