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基于并行计算的分布式数据库树查询全缩减计算方法 被引量:1
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作者 刘云萍 《电脑知识与技术》 2020年第16期50-52,共3页
传统查询全缩减计算方法存在计算速度较慢的缺陷,以此开展了基于并行计算的分布式数据库树查询全缩减计算方法的设计。计算种群中整体数量与样本之间的正向射向关系,设计采样流程图,查询采样条件;设计分布式数据库树查询函数,计算查询... 传统查询全缩减计算方法存在计算速度较慢的缺陷,以此开展了基于并行计算的分布式数据库树查询全缩减计算方法的设计。计算种群中整体数量与样本之间的正向射向关系,设计采样流程图,查询采样条件;设计分布式数据库树查询函数,计算查询数据值,提供计算适应度数值;计算参数数值,完成分布式数据库树查询全缩减计算。经过对比实验,证明所提出的分布式数据库树查询全缩减计算方法可降低查询计算时间,提高计算效率,因此更具有实际应用价值。 展开更多
关键词 并行计算 分布式 数据库树 查询全缩减计算
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基于树结构的数据库设计方案及应用 被引量:2
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作者 罗舒 曹旻 《计算机工程》 CAS CSCD 北大核心 2009年第22期91-93,共3页
在需求不明确的情况下,用传统的数据库设计方法组织数据比较困难,数据层次性较差,且无法设计出一个通用的库,造成设计周期长、代码不易重用等问题,针对该问题提出一种新的基于树的数据库设计方法,该方法简单、直观、易于数据的组织,提... 在需求不明确的情况下,用传统的数据库设计方法组织数据比较困难,数据层次性较差,且无法设计出一个通用的库,造成设计周期长、代码不易重用等问题,针对该问题提出一种新的基于树的数据库设计方法,该方法简单、直观、易于数据的组织,提高数据库设计的灵活性和通用性,在水库移民补偿金信息管理系统中得到较好的应用。 展开更多
关键词 结构 基于数据库 水库移民补偿金计算
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多数据库系统中的全局查询转换方法研究 被引量:7
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作者 李瑞轩 霍晓丽 +2 位作者 文珠穆 卢正鼎 李兵 《计算机工程》 EI CAS CSCD 北大核心 2005年第16期4-6,共3页
使用查询树作为查询转换的内部表示,通过使用多数据库规范树对全局查询树进行规范化处理,并给出了相应的转换规则。最后给出了多数据库查询转换算法,并对查询转换的等价性进行了分析。
关键词 数据库系统 查询转换 查询 数据库规范
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数据库关键词检索中候选元组集连接树生成算法的研究
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作者 白晓亮 《电脑知识与技术》 2011年第6期3753-3755,3765,共4页
在基于关系数据库的关键词检索系统中,在线系统的主要的问题是查询效率低。虽然生成候选元组集连接树并不是造成其效率低的主要因素,但是随着数据库中关系数量的增长,其消耗时间也是造成系统效率的低的一个至关重要的因素。该文给出... 在基于关系数据库的关键词检索系统中,在线系统的主要的问题是查询效率低。虽然生成候选元组集连接树并不是造成其效率低的主要因素,但是随着数据库中关系数量的增长,其消耗时间也是造成系统效率的低的一个至关重要的因素。该文给出了相关定义,并提出一种对数据库进行预处理的算法,然后对两种算法进行了详细的介绍。最后通过实验比较两种算法的效率。 展开更多
关键词 候选元组集连接:数据库模式图:数据库关系
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中华人民共和国人口电子地图集系统设计 被引量:4
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作者 余卓渊 王英杰 +2 位作者 苏莹 谭雨奇 洪伟 《地球信息科学》 CSCD 2005年第2期23-29,共7页
“中华人民共和国人口电子地图集”是我国最新的第五次人口普查数据的集成,是以地图、文字、数字、图表等多种信息表达手段,全面反映了中国人口发展基本现状和趋势的科学参考图集。它可以实现对人口数据的输入/输出、分类、存储、查询... “中华人民共和国人口电子地图集”是我国最新的第五次人口普查数据的集成,是以地图、文字、数字、图表等多种信息表达手段,全面反映了中国人口发展基本现状和趋势的科学参考图集。它可以实现对人口数据的输入/输出、分类、存储、查询、统计、制图、分析和管理,提供给决策者和研究者分析人口问题和制定人口政策的辅助工具。本文详细介绍了图集的系统总体设计、主要功能模块设计、内容组成等。在总体设计上,提出了以电子地图制作子系统、图集管理与集成子系统、图集浏览查询子系统和人口数据查询子系统为四大主要部分的系统结构,并进而对系统中的主要模块进行了介绍.如专题制图符号模型、数据库的目录树管理、电子地图集的管理与集成,通过这些模块,分析了系统的运行机制和流程;在图集内容上,在分析“五普”数据和我国人口实际国情的基础上,选取涉及十项主题(环境、人口分布、性别与年龄、人口变动、民族、家庭婚姻、生育、教育、就业、住房)近200幅地图组成图集的内容,反映我国人口的基本现状、动态变化、地域分布、结构构成等;最后,给出了使用不同制图符号建立的人口地图实例,可以直观地反映各项人口指标的区域差异和变化规律。 展开更多
关键词 人口普查数据 电子地图集 数据库指标 信息系统
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Establishment and Share of Tea Germplasm Database of Yunnan Province 被引量:2
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作者 蒋会兵 矣兵 王平盛 《Agricultural Science & Technology》 CAS 2011年第12期1966-1971,共6页
[Objective] The paper was to establish tea germplasm database of Yunnan Province,and promote sharing of the tea germplasm resources.[Method] Eight hundred and thirty copies of tea germplasm resources of Yunnan Provinc... [Objective] The paper was to establish tea germplasm database of Yunnan Province,and promote sharing of the tea germplasm resources.[Method] Eight hundred and thirty copies of tea germplasm resources of Yunnan Province were first systematically documented by using Access database software,the generic description of 631 tea resources and characteristic description of 300 tea resources were submitted for e-platform,then linked with the national e-platform for natural scientific and technological resources,and the tea germplasm database of Yunnan Province was established.[Result] Based on the conservation and utilization status of tea germplam resources,the sharing and utilization framework of tea germplam resources was presented.Many problems and suggestion about tea germplasm resources in the process of conservation,documentation concordance and sharing were pointed out.For example,conservation areas were separated and system was not completed;the main traits assessment and identification researching work had not completely accomplished and sharing was inefficient.[Conclusion] The paper laid foundation for standardized,digitized and information-based management of tea germplasm resources. 展开更多
关键词 TEA Germplasm resources DATABASE SHARE
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Database-oriented storage based on LMDB and linear octree for massive block model 被引量:6
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作者 毕林 赵辉 贾明涛 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2016年第9期2462-2468,共7页
Data organization requires high efficiency for large amount of data applied in the digital mine system. A new method of storing massive data of block model is proposed to meet the characteristics of the database, incl... Data organization requires high efficiency for large amount of data applied in the digital mine system. A new method of storing massive data of block model is proposed to meet the characteristics of the database, including ACID-compliant, concurrency support, data sharing, and efficient access. Each block model is organized by linear octree, stored in LMDB(lightning memory-mapped database). Geological attribute can be queried at any point of 3D space by comparison algorithm of location code and conversion algorithm from address code of geometry space to location code of storage. The performance and robustness of querying geological attribute at 3D spatial region are enhanced greatly by the transformation from 3D to 2D and the method of 2D grid scanning to screen the inner and outer points. Experimental results showed that this method can access the massive data of block model, meeting the database characteristics. The method with LMDB is at least 3 times faster than that with etree, especially when it is used to read. In addition, the larger the amount of data is processed, the more efficient the method would be. 展开更多
关键词 block model linear octree lightning memory-mapped database mass data access digital mine etree
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An Oracle-based Data Management Method for Large Database in CyberCity GIS 被引量:4
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作者 ZHUQing HUANGDuo +1 位作者 YAOXuefeng ZHANGYeting 《Geo-Spatial Information Science》 2003年第4期39-43,共5页
An Oracle8i-based approach is proposed to manage the integrated databases oflarge CyberCity. This approach consists of three schemes: ① a special R+-tree index is designed toaccelerate spatial retrieving, in which th... An Oracle8i-based approach is proposed to manage the integrated databases oflarge CyberCity. This approach consists of three schemes: ① a special R+-tree index is designed toaccelerate spatial retrieving, in which the bounding boxes of local regions have no intersection andall leaf nodes of the R+-tree (geometry records ) have no repetition; ② different data compressionalgorithms are adopted to compress the digital elevation models, 3D vector models and images, suchas LZ77 lossless compression algorithm for compression of vector data and JPEG compressionalgorithms for texture images; ③ in order to communicate with Oracle8i database, a CyberCity GIS.spatial database engine (SDE) is designed. On the basis of this SDE prototype a case study is done. 展开更多
关键词 CyberCity spatial database engine R+-trees Oracle8i database
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Visualizing Data Tree-Table Based on the Database
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作者 孙广义 侯运炳 +1 位作者 李朝义 张海波 《Journal of China University of Mining and Technology》 2001年第1期56-59,共4页
The data tree table is a type of data structure consisting of data tree and table, which has a wide field of applications. The visual and dynamic growing algorithm of data tree table and its software method are presen... The data tree table is a type of data structure consisting of data tree and table, which has a wide field of applications. The visual and dynamic growing algorithm of data tree table and its software method are presented based on the theory of the data structure and visual technology of software. The method of the expression and management of data tree table with relational mode are explored. 展开更多
关键词 data tree table VISUALIZATION ALGORITHM
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DiagData: A Tool for Generation of Fuzzy Inference System
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作者 Silvia Maria Fonseca Silveira Massruha Raphael Fuini Riccioti Helano Povoas Lima Carlos Alberto AlvesMeira 《Journal of Environmental Science and Engineering(B)》 2012年第3期336-343,共8页
In this paper, it described the architecture of a tool called DiagData. This tool aims to use a large amount of data and information in the field of plant disease diagnostic to generate a disease predictive system. In... In this paper, it described the architecture of a tool called DiagData. This tool aims to use a large amount of data and information in the field of plant disease diagnostic to generate a disease predictive system. In this approach, techniques of data mining are used to extract knowledge from existing data. The data is extracted in the form of rules that are used in the development of a predictive intelligent system. Currently, the specification of these rules is built by an expert or data mining. When data mining on a large database is used, the number of generated rules is very complex too. The main goal of this work is minimize the rule generation time. The proposed tool, called DiagData, extracts knowledge automatically or semi-automatically from a database and uses it to build an intelligent system for disease prediction. In this work, the decision tree learning algorithm was used to generate the rules. A toolbox called Fuzzygen was used to generate a prediction system from rules generated by decision tree algorithm. The language used to implement this software was Java. The DiagData has been used in diseases prediction and diagnosis systems and in the validation of economic and environmental indicators in agricultural production systems. The validation process involved measurements and comparisons of the time spent to enter the rules by an expert with the time used to insert the same rules with the proposed tool. Thus, the tool was successfully validated, providing a reduction of time. 展开更多
关键词 Prediction modelling data mining decision tree machine learning fuzzy inference system fuzzygen.
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