基于多维QoS和云计算的资源负载均衡调度研究

为了实现云环境下虚拟资源的高效调度并满足用户QoS需求,提出了一种基于多维QoS能实现负载平衡的云资源调度方法;首先,建立了云资源调度的多维QoS数学模型,然后提出了一种基于蚁群算法实现云环境虚拟资源调度的算法,对信息素的初始化、虚拟机的选择以及信息素的更新等均进行了改进,并在算法中引入遗传变异因子以提高算法的收敛能力;实验结果表明:该算法能有效解决云环境下虚拟资源调度问题,减少负载均衡离差,较其它方法具有较大优越性,满足了云环境下资源调度的需求。     

基于多维评价模型及改进蚁群优化算法的云计算资源调度策略

针对云计算环境下资源调度模型未充分考虑资源评价的问题,为更好适应不同节点计算性能和大规模数据环境的处理需求,提出了一种基于多维评价模型的虚拟机资源调度策略;首先,在云计算环境下建立包括网络性能在内的多维资源评价模型,在此基础上提出一种改进的蚁群优化算法实现资源调度策略;然后在云计算仿真平台CloudSim上进行实现。实验结果表明,该算法可以更好适应不同网络性能的计算环境,显著提高了资源调度的性能,同时降低了虚拟机负载均衡离差,满足了云计算环境下的虚拟机资源负载均衡需求。     

基于负载均衡的云计算任务调度算法的研究

本文针对当前云计算系统负载不均衡和任务完成效率有待提高的问题,提出了一种基于系统整体负载均衡与最小完成时间LB—ECT算法。根据云计算环境下资源需求动态变化,利用任务在虚拟机上执行时间的预测进行任务到虚拟机上的分配、调度。优化系统的整体效率。采用云计算仿真平台CloudSim对本算法进行仿真实验与分析,实验仿真结果表明,LB—ECT算法能够有效提高系统的整体负载均衡能力．明显缩短任务的总完成时间．     

基于资源权重最大资源利用率的动态资源调度算法

对于在云环境下虚拟机放置问题,资源调度管理是其中一项关键技术,因而提出了一种基于最大综合利用率为标准的动态资源调度算法。首先,在云系统调度中心缓存用户的资源请求,将此请求当做一个任务,然后利用负载均衡调度算法,调度中心针对不同任务来分配适当的物理机,最后在物理机上建立虚拟等待队列,充分考虑云系统中计算资源权重比,利用基于权重最大资源利用率的算法进行虚拟机配置。仿真实验结果证明,该算法可以实现有效负载均衡,并在保证一定的QoS的情况下,能有效提高系统的综合利用率。     

基于蜂群算法的多维QoS云计算任务调度

针对云计算环境下用户日益多样化的QoS需求和高效的资源调度要求,提出了基于改进蜂群算法的多维QoS云计算任务调度算法,其中包括构建任务模型、云资源模型和用户QoS模型。为了获得高效的调度,引入蜂群算法。针对该算法在后期收敛速度变慢且易陷入局部最优的问题,引入收益比、跟随比概念及当前个体最优值及随机向量,避免"早熟"现象的出现。通过实验仿真,将该算法HEFT与和ABC算法进行比较,实验表明,该算法能获得较高的调度效率和用户满意度。     

基于遗传算法的云计算资源调度策略研究

对云计算环境中的资源调度问题进行了研究,鉴于当前云计算环境中资源利用率不高,节点负载不均衡的问题,提出了一种新的基于遗传算法的关于虚拟机负载均衡的调度策略;根据历史数据和系统的当前状态以及通过遗传算法,该策略能够达到最佳负载均衡和减少或避免动态迁移,同时还引入了平均负载来衡量该算法的全局负载均衡效果;最后通过在CloudSim平台进行仿真实验,结果表明,该策略具有相当好的全局收敛性和效率,当系统虚拟机被调度之后,算法在很大程度上能够解决负载不均衡和高迁移成本问题,并且极大地提高了资源利用率.     

云计算中负载优化模型及算法研究

云计算环境的动态性和异构性,使得云计算很容易出现负载失衡现象,严重影响了云计算的整体性能和用户体验.论文提出了基于改进遗传算法的负载均衡优化模型,兼顾资源需求动态变化和虚拟机的计算能力,建立相应的资源调度模型,运用改进遗传算法实现资源负载均衡.验证表明,该算法能很好满足云环境下数据中心的使用要求,提高资源利用率和负载均衡度.     

面向多目标的云计算资源调度算法

在传统的虚拟机资源调度中,仅仅考虑当前负载,对虚拟机历史数据没有充分考虑,在处理云计算资源调度的时候出现负载失衡的状况,为了解决上述问题,本文提出了基于启发式遗传算法的资源调度算法,满足多目标规划的情况下实现云计算资源的调度.算法在为用户提供服务的同时充分考虑虚拟机的各种开销和因素,使提供云计算资源的服务器达到负载均衡.对目前的负载情况和历史数据进行分析,经过搜索和计算,计算得到同时满足负载变化数据约束和最小动态迁移开销的最好的云计算资源调度方案.最后,通过仿真实验,对算法进行验证,通过引入负载变化率和平均负载距离二个性能参数来比较和衡量虚拟机负载.实验数据证明,所提出的算法具有很好的全局收敛性和资源利用率,有效解决在资源调度中出现负载失衡和较大动态迁移开销的问题,因此,算法是可行和有效的.     

一种用于云计算资源调度的双向蚁群优化算法

对云计算环境中的资源调度问题进行了研究,针对蚁群优化算法(ACO)在处理大规模组合优化问题时易陷入搜索速度慢和局部最优解的缺陷,提出了一种实现云计算负载均衡的双向蚁群优化算法(BACO)用于资源调度;该算法考虑到了每个虚拟机的负载和计算能力,同时在云环境中引入了蚂蚁的向前移动和向后移动;最后通过在CloudSim平台进行仿真实验,结果表明该算法的总任务完成时间较短,具有较好的寻优能力,并且能够实现负载均衡,是一种有效的资源调度算法。     

基于迁移技术的云资源动态调度策略研究

现有云资源管理平台存在着瞬时资源利用率峰值易引发迁移、动态负载效果不佳等问题。依据云资源动态调度模型,提出了有效的基于迁移技术的虚拟机动态调度算法。算法将物理节点负载与虚拟机迁移损耗评估、多次触发控制、目标节点定位三者有机结合,实现云计算数据中心高效的动态负载均衡。实验结果表明,该算法优于CloudSim的DVFS调度策略,在保证应用服务水平的同时能减少虚拟机迁移次数和物理机启用数量。     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.