STL hash_map原理以及应用

hash_map基于hashtable(哈希表)。哈希表把数据的存储和查找消耗的时间大大降低,几乎可以看成是常数时间;而代价仅仅是消耗比较多的内存。然后,随着硬件的迅速发展,内存越来越大,通过空间换时间的做法在某些时候是非常值得的。     

多云存储平台资源共享与安全架构设计

针对当前云存储服务架构中由于集中控制方式所造成的主控节点瓶颈问题,提出一种基于P2P和HDFS结合的多云存储架构来为资源共享提供一个安全可靠且可拓展的方案。详细阐述了该架构下的数据存储和安全问题,并提出了利用局部敏感哈希(LSH)实现多云存储平台的快速检索的方案。     

基于哈希表的关联规则挖掘算法研究

经过分析关联规则中Apriori算法存在的不足,为减少对事务数据库的扫描次数,缩减产生频繁项集的时间,列出两种基于哈希表的计算项集支持计数的方法以及利用哈希表来进行项集的地址定位的方法,使得生成频繁项集的效率有所提高。     

基于哈希表的稀疏图像压缩算法研究

随着互联网技术的不断发展,以图像为主要载体的多媒体信息大大丰富了我们的生活。但由于图像数据量庞大,存储和传输时受到很大限制,使得图像压缩成为图像处理中的一个重要环节。图像压缩就是利用图像自身的相关性来消减图像的冗余信息,保留有用的信息。经过多年的研究,人们已经提出了多种图像压缩方法,并在许多领域取得了良好的应用效果。但这些方法主要是针对普通密度的图像,而对于稀疏图像的压缩,目前有效的压缩方法还屈指可数。对图像压缩技术的发展历程进行了回顾,给出了一种基于哈希表的对稀疏数据压缩方法,并利用VC＋＋6．0平台,实现了基于哈希表的数据压缩系统。     

基于FPGA的Deflate算法核心模块设计

基于嵌入式设备FPGA,对无损压缩算法Deflate算法进行加速。采用哈希表方法,把Deflate核心算法用在FPGA上,实现了软硬件协同设计。独创性地设计并实现了窗口大小为32K的Deflate算法。主要介绍该设计的哈希表模块部分。     

西藏特产知识图谱的构建

文章的主要内容为西藏特产知识图谱的构建及可视化研究。首先,运用.csv格式文件存储西藏特产知识图谱的三元组,并采用Protégé本体建模工具进行知识图谱的模型构建,使用Neo4j图型数据库存储西藏特产知识图谱,而后运用Hbuilder软件将其在网页中展示出来,实现可视化查询西藏特产及相关信息。本研究的目的为利用知识图谱及相关技术为西藏非物质文化遗产进行保护和传承,为西藏特产方面的研究提供数据来源与依据。     

最小费用有向树问题的一种贪心算法实现

文章在相关文献研究的基础上抽象出一个求最小费用有向树问题的贪心算法,并基于图的逆邻接表存储结构用c语言实现了该算法。在实现该算法的过程中,采用了基于文件的输入方式来输入一个图,这使得图的输入非常方便,将充分弥补现今大多数书籍和文献中只注重算法设计却忽视算法实现的缺点。     

结合SM Solver和MATLAB的结构内力计算分析方法

本文以主梁为结构内力计算为例,应用结构力学求解器(SM Solver)对工程结构进行内力计算分析,将其结果与系数表人工求解方法所得结果的主要数据进行对比分析,表明采用SM Solver计算的结果满足工程计算精度要求。将SM Solver计算结果导入数学分析软件MATLAB绘制出弯矩内力包络图,很好地解决了系数表人工求解方法中无法得到主梁跨中各控制截面最不利内力的问题。将SM Solver和MATLAB结合起来,提供了一种简便易行的结构内力计算和内力包络图绘制方法。     

网络学习中思维导图动态构建研究

在网络学习中,思维导图用来形象展示知识点间的关系,帮助学习者快速、清晰梳理知识脉络。为适应知识内容的更新,提高学习效率,提出了动态构建思维导图的思想。借助于邻接表存储结构知识库,采用有向无环知识图查找算法和基于隶属关系的知识树遍历算法绘制思维导图。实践证明,使用该方法能够有效提高网络学习效率。     

基于网络的云存储模式的分析探讨

云存储模式是在云计算概念上延伸和发展出来的新概念,是基于网络的数据存储技术,主要提供数据存储和访问服务.本文首先分析了云存储产生的背景、基本概念及其与特点,然后介绍了云存储模式的基本结构,对基本结构中的4层进行分析,并结合Google的云存储系统GFS进行说明,最后就云存储的应用现状进行总结归纳,并分析了云存储的发展方向.     

面向图博档数字化服务融合的知识图谱构建与实现

【 目的/意义】探讨面向图博档数字化服务融合的知识图谱构建与实现。【方法/过程】梳理图博档领域知识图 谱研究和应用现状,研究图博档知识图谱的构建方法,首先构建图博档知识图谱的结构模型,其次设计知识图谱的 构建流程,包括需求分析、数据获取、知识抽取、知识融合、存储设计和图谱绘制,最后以辛亥革命主题为例设计知 识图谱的存储模式,应用Neo4j图数据库存储并实现图博档主题知识图谱。【结果/结论】图博档知识图谱能跨越其 中单一领域的知识壁垒而融合图博档资源,并能可视化展示图博档数字资源之间的语义关联,方便用户知识获取 与知识发现。【创新/局限】本文研究丰富了知识图谱的应用场景,可为图博档数字化服务融合研究提供一种新的知 识可视化呈现及服务方式。     

RelaGraph: Improving embedding on small-scale sparse knowledge graphs by neighborhood relations

Learning a continuous dense low-dimensional representation of knowledge graphs (KGs), known as knowledge graph embedding (KGE), has been viewed as the key to intelligent reasoning for deep learning (DL) and gained much attention in recent years. To address the problem that the current KGE models are generally ineffective on small-scale sparse datasets, we propose a novel method RelaGraph to improve the representation of entities and relations in KGs by introducing neighborhood relations. RelaGraph extends the neighborhood information during entity encoding, and adds the neighborhood relations to mine deeper level of graph structure information, so as to make up for the shortage of information in the generated subgraph. This method can well represent KG components in a vector space in a way that captures the structure of the graph, avoiding underlearning or overfitting. KGE based on RelaGraph is evaluated on a small-scale sparse graph KMHEO, and the MRR reached 0.49, which is 34 percentage points higher than that of the SOTA methods, as well as it does on several other datasets. Additionally, the vectors learned by RelaGraph is used to introduce DL into several KG-related downstream tasks, which achieved excellent results, verifying the superiority of KGE-based methods.     

Bond Graph Modelling of Power Transmission by Torque Converting Mechanisms

Kinematically constrained motion is generally accepted as a fundamental requirement for a mechanism to function as a power transmitting device. There exists, however, a class of mechanism which although kinematically unconstrained, can, by incorporation of energy storage elements, function as a power transmitter. An example of such a mechanism is the automatic, variable ratio power transmission invented in the early twenties by G. Constantinesco, which generated a lot of interest among the engineering fraternity at the time. A typical device consists of a crank-driven nine-bar mechanism which possesses two degrees of mobility. The single velocity (or torque) source supplies the input power, which is transmitted to the output shaft by means of unidirectional drives. The characteristics of the energy storage element in conjunction with a single velocity (or torque) input and the external load fully determine the dynamic behavior of the device. During operation, the input energy is distributed between the load and the energy storage depending on the requirements of the load. For a given input power and external load, the device will adjust the velocity of the output shaft to absorb that power; i.e., it will operate as an automatic, variable ratio power transmission.This paper concentrates on the formulation of a general bond graph model for the mechanism. The model possesses mixed causality and non-linear structure. Some results of digital simulation of the bond graph model of a particular mechanism are provided.     

DECISION TREE COMPLEXITY OF GRAPH PROPERTIES

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Bond graphs in control: Physical state variables and observers

Bond graph modeling techniques yield state equations intimately related to energy storage in physical systems. The easy physical interpretation of the state variables from a bond graph model aids in the realization of modern automatic control schemes involving state variable feedback. When it is inconvenient or impossible or measure certain state variables, the useful device of an observer may be used to estimate the missing state variables. It is shown that the same bond graph used to model the system can be used to derive a complete or reduced order observer. The partial observers use derivative causality in a new way and in some cases, the effects of completely unknown disturbances may be accounted for.     

区域政务微博知识图谱构建及可视化研究

[目的/意义] 借助知识图谱对区域政务微博内容进行知识组织与可视化展示,能够提升用户的知识阅读及获取效率。[方法/过程] 首先,基于LDA模型对区域政务微博进行主题建模,通过依存句法分析对微博内容进行语义三元组抽取。其次,构建了区域政务微博知识模型,形成了知识图谱的语义架构。最后,借助图数据库Neo4j及D3.js插件实现了区域政务微博的知识图谱可视化及关联化保存。[结果/结论] 经理论构型与实际验证,本研究构建了基于主题划分的区域政务微博知识图谱,为社交媒体内容的知识图谱构建提供了一定的思路及方法。     

一种冗余地理数据存储系统

针对地理数据自身的特点和传统存储方案的不足,提出了一种新的冗余地理数据存储系统。该系统具有三层服务器架构。Master服务器对应用层发送的请求进行解析并定位到相应的资源定位服务器。资源定位服务器再根据请求数据的类型和位置定位到相应的数据存储服务器。最后由数据存储服务器和应用层服务器进行数据通讯。实现控制流、数据流的分开以及检索和存储的分开。配合在不同层级上实施的冗余、备份和监控策略,保证了在异常情况下系统的稳定性和可用性。实验以及理论分析都验证了该设计能够完成高效的数据提取和检索,并且具有较高的可信性。     

Some further development on the eigensystem approach for graph isomorphism detection

Many science and engineering problems can be represented by a network, a generalization of which is a graph. Examples of the problems that can be represented by a graph include: cyclic sequential circuit, organic molecule structures, mechanical structures, etc. The most fundamental issue with these problems (e.g., designing a molecule structure) is the identification of structure, which further reduces to be the identification of graph. The problem of the identification of graph is called graph isomorphism. The graph isomorphism problem is an NP problem according to the computational complexity theory. Numerous methods and algorithms have been proposed to solve this problem. Elsewhere we presented an approach called the eigensystem approach. This approach is based on a combination of eigenvalue and eigenvector which are further associated with the adjacency matrix. The eigensystem approach has been shown to be very effective but requires that a graph must contain at least one distinct eigenvalue. The adjacency matrix is not shown sufficiently to meet this requirement. In this paper, we propose a new matrix called adjusted adjacency matrix that meets this requirement. We show that the eigensystem approach based on the adjusted adjacency matrix is not only effective but also more efficient than that based on the adjacency matrix.     

Conceptual navigation in knowledge management environments using NavCon

This article presents conceptual navigation and NavCon, an architecture that implements this navigation in World Wide Web pages. NavCon architecture makes use of ontology as metadata to contextualize user search for information. Based on ontologies, NavCon automatically inserts conceptual links in Web pages. By using these links, the user may navigate in a graph representing ontology concepts and their relationships. By browsing this graph, it is possible to reach documents associated with the user desired ontology concept. This Web navigation supported by ontology concepts we call conceptual navigation. Conceptual navigation is a technique to browse Web sites within a context. The context filters relevant retrieved information. The context also drives user navigation through paths that meet his needs. A company may implement conceptual navigation to improve user search for information in a knowledge management environment. We suggest that the use of an ontology to conduct navigation in an Intranet may help the user to have a better understanding about the knowledge structure of the company.     

基于知识图谱和DSM的研发项目多领域集成管理

   研发项目是涉及顾客需求、产品功能和部件、团队等多知识领域的复杂系统,与大数据技术相关的知识图谱方法可以更加客观全面地展示、分析不同领域间的关联,为此,本文提出新产品开发(NPD)知识图谱,并将其与依赖结构矩阵(DSM)等方法相结合,以识别研发项目中多领域间的相互依赖关系。首先,本文建立依据NPD知识图谱测度顾客需求优先序的模型,并采用DSM和质量功能展开(QFD)方法,建立由“需求-功能”QFD关联推导功能间依赖关系强度的模型。然后,采用“功能-产品”多领域矩阵(MDM)推导部件间的依赖关系强度。最后,对DSM进行聚类,为提高聚类算法的稳定性,采用改进的信息熵,建立了改进的基于信息熵的两阶段DSM聚类模型,算例分析表明,该方法可明显降低类间的协调复杂性并提高算法的稳定性。