元计算环境中任务调度的深入分析

文章主要对元计算环境中任务调度进行了深入分析与研究。先概述了元计算系统对于科学领域的贡献,分析了元计算环境的特点;然后对元计算环境中的调度算法进行了分类说明,并对几种典型的调度算法行了具体的分析,评价了其特点与不足之处;最后分析了新兴的元计算环境—校园级元计算环境面临的挑战,借鉴各种调度算法,提出了与之相适应的任务调度策略,对其可行性进行了分析,并简要概括了其创新性。     

几种三层小波提升方案及其在图像压缩中的应用

1 引言小波理论在图像压缩中已有成功的应用。在小波压缩系统中,有两个因素是至关重要的:一是小波滤波器,二是压缩编码算法。随着小波变换进入JPEG2000,与小波变换相配套的零树编码算法写进MPEG-4,小波理论在图像压缩中也占有越来越重要的地位。基于提升算法的第二代小波变换也日益受到研究者的广泛关注。与第一代小波变换相比,提升算法具有快速、高效的优点,并且提升滤波器的设计可直接在空域中完成。第一代小波变换可通过因数分解转换为提升方案,例如著名的Cohen和     

Local networking at the Royal Bank of Scotland

Data communications facilities are vital if essential banking operations are to be computerized; branches and head offices that are dependent upon terminals and corporate data to fulfil their functions must have access to such facilities. Back-up facilities are also essential if normal bank functions are not to be disrupted should a fault develop. Investigations that led to the installation of Hyperchannel at the Royal Bank of Scotland are described and the problems to which Hyperchannel provided the solutions are examined. The implementation of the system and plans for future development are discussed.     

基于粘贴模型的两类全排问题的DNA算法

基于粘贴模型的巨大并行性,分别给出了线性全排列和圆周全排列问题的粘贴DNA算法;分析了两类问题的DNA算法的不同之处;通过一个实例给出了实验操作步骤,并对生化实验进行了模拟,得出了正确的结果,从而证明了算法的可行性。最后,对算法的操作复杂度进行了分析。     

扰动模糊有限转换状态机

引入了扰动模糊有限转换状态机和扰动模糊有限状态机的（强）同态的概念,研究了它们的相关性质。给出了[Σ]的元素构成所有长度有限的词集上的两种同余关系,讨论商结构问题,证明了相应的所有等价类构成具有单位元的有限半群,并且这两个有限半群是同态的。给出了[Q]上容许关系及强同态的核的概念,研究了它们的相关性质。     

无线传感器网络1点和2点连通可靠性研究

无线传感器网络集成了传感器、微机械电子和网络通讯技术,它的巨大应用前景引起了军事部门、工业界和学术界的广泛关注.它的节点不是预先安置,而是随机撒放,那么就有问题:在假定每个传感器节点通讯半径一定,一个固定区域要抛撒多少节点才能保证这些节点组织的网络基本连通?要抛撒多少节点才能保证满足2点间的连通可靠性.本文进行了大量的计算机模拟试验,采用了随机抛撒节点,然后进行连通度测试的方法,给出了节点数、通讯半径和连通关系的曲线簇.通过对曲线簇的对数变换和对变换后曲线簇的回归分析,给出了仿真区间内的单点连通和二点连通的经验公式,取得了满意的效果.给出了通过几何变换可能推广任意通讯半径的方法.本文同时给出了在仿真中的重要参数:随机抛撒均匀分布的节点的邻居节点的分布规律,抛撒后节点满足通讯半径要求建立的连接数的分布规律.这些直接指导无线传感器网络的节点个数和通讯半径选择,连通可靠性设计.     

磁盘加密模式分析

基于国内外磁盘加密产品的研究成果,通过跟踪IEEE存储安全工作组(SISWG)制定的块存储设备加密标准P1619,分析磁盘加密的特定需求,指出其在国内研究的欠缺。选取目前主流的加密模式进行安全性分析,根据其在应用中的优缺点,给出相应建议,并总结磁盘加密算法研究的发展方向。     

Continuous attractors of a class of neural networks with a large number of neurons

A class of simplified background neural networks model with a large number of neurons is proposed. Continuous attractors of the simplified model are studied in this paper. It contains: (1) When the background inputs are set to zero and the excitatory connections are in Gaussian shape, continuous attractors of the new network are obtained under some condition. (2) When the background inputs are nonzero and the excitatory connections are still in Gaussian shape, continuous attractors are achieved under some appropriately selected condition. (3) Discussions and examples are used to illustrate the theories developed.     

粒子滤波算法综述

对粒子滤波算法的原理和应用进行综述．首先针对非线性非高斯系统的状态滤波问题．阐述粒子滤波的原理;然后在分析采样-重要性-重采样算法基础上．讨论粒子滤波算法存在的主要问题和改进手段;最后从概率密度函数的角度出发．将粒子滤波方法与其他非线性滤波算法进行比较．阐明了粒子滤波的适应性．给出了粒子滤波在一些研究领域中的应用．并展望了其未来发展方向．     

基于贝叶斯滤波理论的自主机器人自定位方法研究

针对自主机器人定位问题，研究了基于贝叶斯滤波理论的自定位方法,从概率表达的角度介绍了贝叶斯滤波方法各种不同的实现形式，分析了各种不同定位方法的性能，指出了它们的优缺点，并对每种方法的改进方法进行了探讨和分析,最后总结了定位方法的基本特点，并对贝叶斯滤波理论在自主机器人领域中的应用前景进行了展望，探讨了未来的发展方向。     

Compound solitons in fiber Bragg grating

Single soliton and compound solitons are described by coupled-mode equation. It is noted that three parameters, which are dimensionless group velocity, normalized frequency, and grating strength, influence formed solitons by emulation. The novel designs of parallel and serial multi-grating are advanced, and the compound solitons formed from parallel multi-grating are linear superposition; the compound solitons formed from serial multi-grating are nonlinear superposition, and finally two general formulae are obtained. Furthermore, it is theoretically shown that the compound grating solitons are prominent and flexible signals in optical communication.     

多生物特征识别技术综述

介绍了生物认证的发展状况和多生物特征提出的背景，提出了多生物特征认证的整体框架和具体参数的表征，并对不同的整合方法做了比较，分析了各自的优缺点。提出了最后关于多生物特征识别发展的看法。     

Dynamical difference equations

Dynamical difference equations are motivated and developed. Conservation and covariance laws are proved. Illustrative examples are described and discussed. Newtonian equations are stressed, but extensions to relativity and quantum mechanics are indicated. The physical problem of convergence to the limit as the time step goes to zero is shown to reveal an area in which quantum mechanics and relativity are in disagreement.     

综述：知识系统的V＆V技术

知识库的异常是影响整个知识系统性能的重要因素之一，因此必须对获取的知识进行校验。本文综述了知识库异常检测和验证的相关研究，给出了异常知识的分类及其危害性，分析了知识库验证困难的原因，介绍了用于知识库验证的静态和动态方法，列举了国际上几个著名的知识库验证工具，并对知识库验证的研究进行了展望。     

常见模糊蕴涵算子的模糊系统及其响应函数

详细讨论了较常见的21种模糊蕴涵算子构成的模糊控制器及其响应函数.主要结果是,异常蕴涵算子模糊控制算法都可归结为某种插值方法,它们相应的模糊控制器均具有函数逼近的泛性且彼此等效;而正常蕴涵算子(包括正规蕴涵算子的导出算子)模糊控制算法均非插值方法,其模糊控制器都不具有函数逼近的泛性,除Zadeh蕴涵算子外,这些正常蕴涵算子的模糊控制器均只具备阶跃输出功能且在一定意义下相互等效.     

Comparison of thinning algorithms on a parallel processor

A number of parallel algorithms for thinning elongated shapes are contrasted and compared on a Clip 4 parallel processor. These algorithms all work in rectangular tessellation and they thin elongated objects to lines one pixel thick while retaining their connectivity. Existing algorithms for use on binary pictures are considered first and new algorithms are proposed which produce more satisfactory results, but are more expensive in terms of speed and space requirements. Two methods of extending these algorithms to grey pictures are then considered. In one method, binary algorithms are used but are directed by the grey pixels; in the other the binary algorithms are generalized to the grey case. Both methods result in arcs which are not wholly determined by the original boundary of the object but lie along darker ridges. The former is faster and produces results which are easier to interpret, but the results from the latter contain more information.     

大流识别方法综述

首先介绍大流识别方法的研究动机和国内外发展现状,根据采用技术的差异,将现有方法分为基于抽样的方法、基于计数的方法、基于最近最少使用算法的方法和基于哈希的方法,简要分析了几类方法的优缺点;然后分别选取经典算法进行剖析,并给出大流识别的典型应用;最后探讨了值得进一步研究的问题和可能的发展方向.     

UBI-HIT联合硕士课程的正规模型(英文)

Existing university training curricular are usually presented using text and tables.Semantics and inter-relationships between courses are often implicit or even not defined.This paper tentatively presents a formal model of the joint UB1-HIT international master curriculum.The courses of the two years are modelled using UML and the relationships between the two years are explicitly shown.Complementarities between years 1 and 2 are also identified and possible improvements are discussed.     

基于FPGA及FLASH的数据采集存储系统设计

提出了一种多路数据采集存储系统的设计方法。介绍了闪存和现场可编程门阵列FPGA的功能特性,并利用外围接口电路及上述芯片设计并实现数据采集存储系统。介绍并口EPP模式控制的读数操作过程。给出了采集存储系统的接口电路,并阐述了它的实现原理。