Fibonacci序列构造z-2+c广义M-J混沌分形图谱及其标度不变性的研究

利用周期分类法绘制了z^-2 c的广义M—J集分形图，分析了广义M集周期芽苞同分岔图的对应关系，发现其广义M集周期芽苞的Fibonacci序列的拓扑不变性。通过大量计算机数学试验，发现了主轴上倍周期芽苞在超吸引点处的符号序列的排列规律，给出了构造广义M集任意倍周期芽苞字提升方程的一个算法，得到主轴上各倍周期芽苞的超吸引点，通过大量计算结果猜测M集倍周期芽苞存在一个普适常数δ，Julia集存在一个标度因子。     

基于三维多项式映射的广义Julia集表示与绘制

研究了基于三维多项式映射的三维广义Julia集表示方法.从理论上分析并证明了三维多项式映射满足等变的条件,精确地给出了关于正四面体群和正八面体群具有旋转不变对称性的两类三维等变映射的具体公式,在此基础上讨论并证明了三维多项式映射的广义Julia集所具有的性质.提出了基于逃选距离色彩调配的光线跟踪体绘制算法,对给定三维空间中属于Julia集的离散点根据其逃逸距离赋予颜色和不透明度,并采用光线跟踪法进行体绘制.实验结果表明,利用三维多项式映射来构造三维Julia集,不仅可以根据映射的性质预知Julia集的总体结构特征,并且能够通过调控映射的参数来获得多种具有不同旋转对称结构的Julia集,因而有效地克服了现有三维分形集生成方法所构造的分形集包含信息量少、形状结构单一和分形形状无法预测等缺陷.进一步地,三维多项式映射可以应用于其他三维分形的构造,从而为三维分形的生成提供一个新的有效途径.     

复映射z←(-z)-a+c(a≥2)的广义M集及其对称周期检测法

研究了指数为负实数的非解析复映射z←(-z)-a+c(a≥2)的广义Mandelbrot集.分析和证明了(取不同值时该映射的广义M集所具有的性质,严格地给出了(为正整数时复映射周期1轨道稳定区域边界的参数方程.提出了对称周期检测法,根据各参数点的周期值对M集进行着色,并充分利用M集的对称性来减少绘制过程中计算周期时所需要的迭代运算.实验结果表明,新算法在获得高质量M分形图的同时具有较高的绘制速度.进一步地,新算法可以推广到其他M(Mandelbrot)集和J(Julia)集的绘制.     

复映射z←()~(-a)+c(a≥2)的广义M集及其对称周期检测法

研究了指数为负实数的非解析复映射()()2+-aaczz的广义Mandelbrot集.分析和证明了a取不同值时该映射的广义M集所具有的性质,严格地给出了a为正整数时复映射周期1轨道稳定区域边界的参数方程.提出了对称周期检测法,根据各参数点的周期值对M集进行着色,并充分利用M集的对称性来减少绘制过程中计算周期时所需要的迭代运算.实验结果表明,新算法在获得高质量M分形图的同时具有较高的绘制速度.进一步地,新算法可以推广到其他M(Mandelbrot)集和J(Julia)集的绘制.     

复映射z←(z)-a+c(a≥2)的广义M集及其对称周期检测法

研究了指数为负实数的非解析复映射z←(z)^-a+c(a≥2)的广义Mandelbrot集.分析和证明了(取不同值时该映射的广义M集所具有的性质,严格地给出了(为正整数时复映射周期1轨道稳定区域边界的参数方程.提出了对称周期检测法,根据各参数点的周期值对M集进行着色,并充分利用M集的对称性来减少绘制过程中计算周期时所需要的迭代运算.实验结果表明,新算法在获得高质量M分形图的同时具有较高的绘制速度.进一步地,新算法可以推广到其他M(Mandelbrot)集和J(Julia)集的绘制.     

超复数系统中的高维广义M-J集

研究超复数算法优化问题,由于超复数系统中构造曼德勃罗-茱莉亚集(M-J集)的算法目前还停留在三元数和四元数水平,且仅实现了低维M-J集在2-D和3-D截面上的仿真.为了更深入研究分形结构的特征性质,使用倍增和截去方法建立了任意维的超复数系统,讨论了超复数系统中的加法和乘法运算是闭的前提条件,并给出了超复数系统中高维(任意偶数维)广义M-J集的定义及构造算法.通过选取不同参数,实现并绘制了不同维度广义M-J集的2-D截面,对2-D截面的分形结构特征进行分析,结果表明高维广义M-J集在不同水平上的自相似性,并理论证明了2-D截面的对称性.有关对称性的分析将有助于进一步研究超复数动力学.     

一类复指数映射的复合的广义M-J集

一种常见的构造分形图象的方法是利用复映射的迭代,所使用的一般是复幂映射和复指数映射.Shirriff 在文献[1]中描述了一种利用两个复映射的复合构造分形图象的方法,不过在那里只使用了两个简单的复多项式映射.本文将Shirriff的方法进行了推广,构造了两个复指数映射的复合的广义M集和广义J集,证明了广义M集和广义J集的一些性质.通过大量的计算机实验,总结了广义M集和广义J集的演化规律,并从理论上分析了当两个复映射的参数变化时,广义J集的变化规律.     

广义Julia分形图对迭代参数依赖性的研究

采用逃逸时间算法对ω∈Z时,参数c与广义Julia分形图之间的关系进行大量实验研究,总结得出当参数ω为奇数,参数c为反共轭时所构造的广义Julia集关于虚轴对称,并进一步对结论进行理论上的证明。     

改进单纯形算法构造平面结晶体群动力系统的广义M集

针对逃逸时间算法计算量大，构图时间长的特点，本文提出了改进的有约束的单纯形最优化方法，求解了使平面结晶体群映射的Jacobin矩阵｜DF｜=0的点集作为初始迭代点集。由Lyapunov指数判定初始迭代点集的动力学特性，构造了平面结晶体群动力系统的广义M集．研究表明。运用改进的有约束的单纯形法构造非解析映射的广义M集这一方法是有效可行的，改进方法大大提高了平面结晶体群广义M集的构造速度．实现了对参数空间的有效划分．改进单纯形法构造的广义M集的混合区域更为准确地反映了相应动力平面上的动力学特性．     

Newton法对应单参有理函数族的广义M-J集

讨论了Newton法对应单参数有理函数族的广义Mandelbrot集和Julia集,给出了它们的构造算法,证明了其广义Mandelbrot集的有界性,并给出了其周期点个数的计算公式.利用数学实验的方法研究了广义Mandelbrot集周期芽苞分布规律,并通过对比分析得到了它们与z~n+c的Mandelbrot集和Julia集之间的族相似性类似的新的族相似关系.文中算法为Mandelbrot集和Julia集的发展提供了新的思路.     

Call for Papers The 6^th International Conference on Grid and Cooperative Computing

Recent years have seen rapid advances in various grid-related technologies, middleware, and applications. The GCC conference has become one of the largest scientific events worldwide in grid and cooperative computing. The 6th international conference on grid and cooperative computing (GCC2007) Sponsored by China Computer Federation (CCF),Institute of Computing Technology, Chinese Academy of Sciences (ICT) and Xinjiang University ,and in Cooperation with IEEE Computer Soceity ,is to be held from August 16 to 18, 2007 in Urumchi, Xinjiang, China.     

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.     

法律信息库系统

本文分析了法律数据库的结构和特点，介绍了采用面向对象设计方法和超文本数据库技术开发和实现法律信息库系统将作为重要网络资源之一为不同用户进行法律咨询服务。     

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.     

International Journal of Automation and Computing Table of Contents

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Information for authors

正SCIENCE CHINA Information Sciences(Sci China Inf Sci),cosponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China,and published by Science China Press,is committed to publishing highquality,original results of both basic and applied research in all areas of information sciences,including computer science and technology;systems science,control science and engineering(published in Issues with odd numbers);information and communication engineering;electronic science and technology(published in Issues with even numbers).Sci China Inf Sci is published monthly in both print and electronic forms.It is indexed by Academic OneFile,Astrophysics Data System(ADS),CSA,Cabells,Current Contents/Engineering,Computing and Technology,DBLP,Digital Mathematics Registry,Earthquake Engineering Abstracts,Engineering Index,Engineered Materials Abstracts,Gale,Google,INSPEC,Journal Citation Reports/Science Edition,Mathematical Reviews,OCLC,ProQuest,SCOPUS,Science Citation Index Expanded,Summon by Serial Solutions,VINITI,Zentralblatt MATH.     

Erratum to: Fast global kernel fuzzy c-means clustering algorithm for consonant/vowel segmentation of speech signal

正Erratum to:J Zhejiang Univ-Sci C(ComputElectron)2014 15(7):551-563doi:10.1631/jzus.C1300320The original version of this article unfortunately contained mistakes.Algorithm 6 should be as follows:Algorithm 6 FGKFCM-F clustering Input:(1)X={x_1,x_2,…,x_N},,x_iR~d,i=1,2,…,N,the dataset;(2)C,1C≤N,the number of clusters;(3)ε0,the stopping criterion;     

Journal of Zhejiang University-SCIENCE C (Computers & Electronics) Total contents

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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.