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本文分析了当前网络考试系统数据挖掘现状,介绍了云计算和数据挖掘的相关概念,指出传统数据挖掘技术在当今考试系统海量数据情况下挖掘时系统响应速度慢,负载不均衡和节点效率低的不足,设计了基于Map/Reduce并行编程模型的Apriori算法,利用云计算环境下计算资源来支持该算法的并行执行,通过实例说明云计算化后的Apriori算法在对海量考试数据进行挖掘时能获得更高的挖掘效率。 相似文献
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先介绍了云计算产生的背景、概念、基本原理和体系结构,然后以Google系统为例详细阐述了云计算的实现机制。云计算是并行计算、分布式计算和网格计算等计算机科学概念的商业实现。Google拥有自己云计算平台,提供了云计算的实现机制和基础构架模式。该文阐述了Google云计算平台:GFS分布式文件、分布式数据库BigTable及Map/Reduce编程模式。最后分析了云计算发展所面临的挑战。 相似文献
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首先介绍了云计算产生的背景、概念、基本原理和体系结构,然后以Google系统为例详细阐述了云计算的实现机制。云计算是并行计算、分布式计算和网格计算等计算机科学概念的商业实现。Google拥有自己云计算平台,提供了云计算的实现机制和基础构架模式。该文阐述了Google云计算平台:GFS分布式文件、分布式数据库BigTable及Map/Reduce编程模式。最后分析了云计算发展所面临的挑战。 相似文献
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Andreas Wilke Jared Wilkening Elizabeth M. Glass Narayan L. Desai Folker Meyer 《Concurrency and Computation》2011,23(17):2250-2257
Existing applications in computational biology typically favor a local cluster based integrated computational platform. We present a lessons learned type report for scaling up an existing metagenomics application that outgrew the available local cluster hardware. In our example, removing a number of assumptions linked to tight integration allowed to expand beyond one administrative domain, increase the number and type of machines available for the application, and also improved scaling properties of the application. The assumptions made in designing the computational client make it well suitable for deployment as a virtual machine inside a cloud. This paper discusses the decision process and describes the suitability of deploying various bioinformatics computations to distributed heterogeneous machines. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
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A.J. Berlanga P. van Rosmalen H.P.A. Boshuizen P.B. Sloep 《Journal of Computer Assisted Learning》2012,28(2):146-160
Learners, particularly lifelong learners, often find it difficult to determine the scope of their expertise. Formative feedback could help them do so. To use this feedback productively, it is essential to then suggest to them the remedial actions they need to overcome the gaps in their knowledge. This paper presents the design considerations of a support tool that aims at providing formative feedback on textual assignments. It does so by facilitating comparisons between learner's input texts and group input texts with respect to the intended learning outcomes. Using language technologies, the tool automatically extracts the concepts and relations of input texts; it then creates visual representations that can be put side by side to identify conceptual overlaps and missing concepts. The paper first introduces the theoretical underpinnings of the tool – specifically those concerning expertise development, knowledge creation and assessment of knowledge. It then draws up design considerations and clarifies how the tool should work. Next, it discusses the results of an initial study in which word clouds and concept maps have been applied to generate graphical visual representations. These help learners identify overlapping and missing core concepts, both in individual texts and in a compiled group text. Finally, the paper provides conclusions and directions for future work. 相似文献
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Big data is largely influencing business entities and research sectors to be more data‐driven. Hadoop MapReduce is one of the cost‐effective ways to process large scale datasets and offered as a service over the Internet. Even though cloud service providers promise an infinite amount of resources available on‐demand, it is inevitable that some of the hired virtual resources for MapReduce are left unutilized and makespan is limited due to various heterogeneities that exist while offering MapReduce as a service. As MapReduce v2 allows users to define the size of containers for the map and reduce tasks, jobs in a batch become heterogeneous and behave differently. Also, the different capacity of virtual machines in the MapReduce virtual cluster accommodate a varying number of map/reduce tasks. These factors highly affect resource utilization in the virtual cluster and the makespan for a batch of MapReduce jobs. Default MapReduce job schedulers do not consider these heterogeneities that exist in a cloud environment. Moreover, virtual machines in MapReduce virtual cluster process an equal number of blocks regardless of their capacity, which affects the makespan. Therefore, we devised a heuristic‐based MapReduce job scheduler that exploits virtual machine and MapReduce workload level heterogeneities to improve resource utilization and makespan. We proposed two methods to achieve this: (i) roulette wheel scheme based data block placement in heterogeneous virtual machines, and (ii) a constrained 2‐dimensional bin packing to place heterogeneous map/reduce tasks. We compared heuristic‐based MapReduce job scheduler against the classical fair scheduler in MapReduce v2. Experimental results showed that our proposed scheduler improved makespan and resource utilization by 45.6% and 47.9% over classical fair scheduler. 相似文献
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Hautaniemi Sampsa Yli-Harja Olli Astola Jaakko Kauraniemi Päivikki Kallioniemi Anne Wolf Maija Ruiz Jimmy Mousses Spyro Kallioniemi Olli-P. 《Machine Learning》2003,52(1-2):45-66
cDNA microarrays permit massively parallel gene expression analysis and have spawned a new paradigm in the study of molecular biology. One of the significant challenges in this genomic revolution is to develop sophisticated approaches to facilitate the visualization, analysis, and interpretation of the vast amounts of multi-dimensional gene expression data. We have applied self-organizing map (SOM) in order to meet these challenges. In essence, we utilize U-matrix and component planes in microarray data visualization and introduce general procedure for assessing significance for a cluster detected from U-matrix. Our case studies consist of two data sets. First, we have analyzed a data set containing 13,824 genes in 14 breast cancer cell lines. In the second case we show an example of the SOM in drug treatment of prostate cancer cells. Our results indicate that (1) SOM is capable of helping finding certain biologically meaningful clusters, (2) clustering algorithms could be used for finding a set of potential predictor genes for classification purposes, and (3) comparison and visualization of the effects of different drugs is straightforward with the SOM. In summary, the SOM provides an excellent format for visualization and analysis of gene microarray data, and is likely to facilitate extraction of biologically and medically useful information. 相似文献
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单机运行环境难以满足海量空间数据的连接聚集操作对时空开销的需求,集群上的并行计算是高效处理海量空间数据的连接聚集操作的关键. Map-Reduce是云计算中一种应用于大规模集群进行大规模数据处理的分布式并行编程模型,分析发现,Map-Reduce并不直接支持以既高效又自然的方式来处理具有二次归约特征的并行空间连接聚集操作.因此,提出了一种并行计算模型——Map-Reduce-Combine(MRC)来有效地处理大规模空间数据的连接聚集操作.MRC在Map-Reduce 模型上增加一个Combine阶段,有效地合并分散在各个Reducer的部分聚集结果.针对并行任务划分中空间对象的单分配问题,提出了过滤优化算法,提高了MRC下处理空间连接聚集查询的效率.实验验证所提出的并行计算模型在处理空间连接聚集查询时具有良好的效率、有效性、可扩展性和简单性. 相似文献
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林嘉颖 《电脑编程技巧与维护》2009,(20):29-30
随着互联网技术与应用的普及和深入,云计算的技术逐步被人们理解和接受,并得到了广泛的应用。云计算的基础是自动化技术,只有充分利用好自动化技术,才能更好地发挥云计算效能。文中从云、云计算的概念及其技术应用角度出发,分析了云计算与自动化之间的关系。 相似文献
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南凯 《数据与计算发展前沿》2016,7(1):10-14
社区云是云计算四种部署模式中应用较少的一种,但对于面向科研和学术界的云服务却有其特点和优势,非常值得探索。本文结合中国科学院科技云的实践,讨论了身份管理与授权、服务集成、测量与运行管理三项关键技术,提出了一种适合社区云的联盟和微服务架构,并指出社区云在模式和机制、可靠性、安全、组织管理等方面所面临的挑战。 相似文献
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生物信息集成研究综述 总被引:1,自引:0,他引:1
随着计算机和生物技术的发展,生物信息集成已经成为一个重要的研究领域.在当前的实际应用中,分析设计生物信息集成系统已成为生物信息学领域的研究热点.本文讨论了生物信息集成所采用的主要方法,分析了著名的生物信息集成系统,并对将来的研究主题进行了展望. 相似文献
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针对荒野环境中的特征稀少,传统的通过提取点云特征点进行匹配的点云配准方法无法准确地进行定位的问题,提出了一种先建立离线点云地图,再利用离线地图进行定位的定位方法.建图过程使用GPS、IMU、激光点云信息,利用GPS信息优化正态分布变换配准算法的配准过程,建立高精度的离线点云地图;定位过程先加载离线地图,使用激光点云、I... 相似文献
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云计算技术目前已在一些商业领域中得到了初步的应用。该文探讨了云计算技术在图书馆中的应用,分析了图书馆应用云计算技术的优缺点。 相似文献
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云技术的进步推动了电子政务云的发展,大大提高了国内电子政务水平和效率。随着信息化建设质量要求的提升,电子政务云的测试成为电子政务云建设不可分割的一部分,而针对电子政务云的测试研究却相对有限。本文通过对典型电子政务云进行架构分析,从其组成上分别论述了的电子政务云应包含的主要测试内容,包括机房环境测试、服务器测试、云核心局域网测试、云调度软件测试、光纤网络测试,并对测试的关键内容进行了论述。 相似文献
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政府部门建立以云技术为条件的电子政务安全信息系统,这是电子政务建设的未来发展方向.本文首先介绍了云技术、系统建设目标和任务,然后对系统框架进行了概述,最后详细介绍了云技术条件下电子政务安全信息系统的建设实践. 相似文献
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生物信息学中数据库技术的应用 总被引:2,自引:1,他引:1
刘智珺 《计算机与数字工程》2009,37(5):157-159
生物信息学是以计算机为工具对生物信息进行存储、检索和分析的科学。综述分析了在生物信息学中几种重要的数据库及其应用,并对现状进行了分析与展望。 相似文献
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阴影是树木的重要视觉特征,对提高树木绘制的真实感具有重要意义,同时阴影算法的效率也是影响树木绘制效率的重要因素.文中针对树木建模中广泛应用的布告板云(Billboard Cloud)树木模型的特点,提出了Billboard Cloud树木模型阴影快速生成与真实感绘制算法.在传统阴影图算法基础上,采用深度变换的方法解决了Billboard的自遮挡问题,使用阴影图滤波和屏幕阴影图滤波相结合的方法实现了树木软影效果,并利用图形硬件的多绘制目标功能对上述算法流程进行了优化,以提高算法效率.最后以SpeedTree树木模型为例进行了实验,结果表明,文中算法生成的Billboard Cloud树木阴影真实感强,且具有较高的效率. 相似文献