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Software Metric Analysis of Open-Source Business Software
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作者 Charles W. Butler 《Journal of Software Engineering and Applications》 2023年第5期144-153,共10页
Over the past decade, open-source software use has grown. Today, many companies including Google, Microsoft, Meta, RedHat, MongoDB, and Apache are major participants of open-source contributions. With the increased us... Over the past decade, open-source software use has grown. Today, many companies including Google, Microsoft, Meta, RedHat, MongoDB, and Apache are major participants of open-source contributions. With the increased use of open-source software or integration of open-source software into custom-developed software, the quality of this software component increases in importance. This study examined a sample of open-source applications from GitHub. Static software analytics were conducted, and each application was classified for its risk level. In the analyzed applications, it was found that 90% of the applications were classified as low risk or moderate low risk indicating a high level of quality for open-source applications. 展开更多
关键词 open-source Software Software Quality Software Risks Cyclomatic Complexity Essential Complexity Module Design Complexity Design Complexity Integration Complexity Local Data Complexity Public global Data Complexity Parameter Data Complexity Risk Score Risk Classification
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A relational database of global U-Pb ages 被引量:2
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作者 Stephen J.Puetz 《Geoscience Frontiers》 SCIE CAS CSCD 2018年第3期877-891,共15页
Enhanced understanding of how sampling techniques affect estimates of the global U-Pb age-distribution have, in turn, constrained U-Pb database design. Recent studies indicate that each continent has a unique age-dist... Enhanced understanding of how sampling techniques affect estimates of the global U-Pb age-distribution have, in turn, constrained U-Pb database design. Recent studies indicate that each continent has a unique age-distribution, as determined by zircon ages dated by the U-Pb isotope method. Likewise, broad regions within a continent also exhibit diverse age-distributions. To achieve a reliable estimate of the global distribution, the heterogenous composition of the continental crust requires sampling as many regions as feasibly possible. To attain this goal, and to provide a method for calculating age histograms, the records from a recent global U-Pb compilation are supplemented with 281,631 new records. These additions increase the database size to 700,598 records. In addition, the data are now restructured and made available as a relational database. After filtering the records by the six age-models included with the database, the results reveal two problems that might generally be unrecognized. First, an abrupt switch in the best-age at any given point(such as 1000 Ma) from ^(206)Pb/^(238)U ages to ^(207)Pb/^(206)Pb ages artificially depresses the age-distribution at the cutoff point. Second, rejecting analyses based on either absolute discordance or the magnitude of 2σ precision errors artificially depresses the age-distribution between 900 Ma and 2000 Ma. The results indicate that, when estimating the global U-Pb age-distribution, the methods for determining best-age and for rejecting records both require some attention. Possible solutions include using either an Accuracy Model or a Precision Model for estimating best-age, and then including all U-Pb records in the estimate, rather than rejecting any of them. 展开更多
关键词 U-Pb age-distribution HISTOGRAM global database Sampling FILTERING ZIRCON
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A method of estimating the Martian neutral atmospheric density at 130 km, and comparison of its results with Mars Global Surveyor and Mars Odyssey aerobraking observations based on the Mars Climate Database outputs 被引量:1
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作者 JunFeng Qin Hong Zou +3 位作者 YuGuang Ye YongQiang Hao JinSong Wang Erling Nielsen 《Earth and Planetary Physics》 CSCD 2020年第4期408-419,共12页
Profiles of the Martian dayside ionosphere can be used to derive the neutral atmospheric densities at 130 km,which can also be obtained from the Mars Climate Database(MCD)and spacecraft aerobraking observations.In thi... Profiles of the Martian dayside ionosphere can be used to derive the neutral atmospheric densities at 130 km,which can also be obtained from the Mars Climate Database(MCD)and spacecraft aerobraking observations.In this research,we explain the method used to calculate neutral densities at 130 km via ionosphere observations and three long-period 130-km neutral density data sets at northern high latitudes(latitudes>60°)acquired through ionospheric data measured by the Mars Global Surveyor(MGS)Radio Occultation Experiment.The calculated 130-km neutral density data,along with 130-km density data from the aerobraking observations of the MGS and Mars Odyssey(ODY)in the northern high latitudes,were compared with MCD outputs at the same latitude,longitude,altitude,solar latitude,and local time.The 130-km density data derived from both the ionospheric profiles and aerobraking observations were found to show seasonal variations similar to those in the MCD data.With a negative shift of about 2×10^10 cm^−3,the corrected 130-km neutral densities derived from MCD v4.3 were consistent with those obtained from the two different observations.This result means that(1)the method used to derive the 130-km neutral densities with ionospheric profiles was effective,(2)the MCD v4.3 data sets generally overestimated the 130-km neutral densities at high latitudes,and(3)the neutral density observations from the MGS Radio Science Experiment could be used to calibrate a new atmospheric model of Mars. 展开更多
关键词 Martian upper atmosphere Mars Climate database v4.3 aerobraking observations Mars global circulation
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Use of Component Integration Services in Multidatabase Systems: A Feasible Solution for Integrating Academic Institutions or Commercial Industries
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作者 Mohammad Ghulam Ali Mohammad Ghulam Murtuza 《Journal of Software Engineering and Applications》 2023年第11期561-585,共25页
The book chapter is an extended version of the research paper entitled “Use of Component Integration Services in Multidatabase Systems”, which is presented and published by the 13<sup>th</sup> ISITA, the... The book chapter is an extended version of the research paper entitled “Use of Component Integration Services in Multidatabase Systems”, which is presented and published by the 13<sup>th</sup> ISITA, the National Conference of Recent Trends in Mathematical and Computer Sciences, T.M.B. University, Bhagalpur, India, January 3-4, 2015. Information is widely distributed across many remote, distributed, and autonomous databases (local component databases) in heterogeneous formats. The integration of heterogeneous remote databases is a difficult task, and it has already been addressed by several projects to certain extents. In this chapter, we have discussed how to integrate heterogeneous distributed local relational databases because of their simplicity, excellent security, performance, power, flexibility, data independence, support for new hardware technologies, and spread across the globe. We have also discussed how to constitute a global conceptual schema in the multidatabase system using Sybase Adaptive Server Enterprise’s Component Integration Services (CIS) and OmniConnect. This is feasible for higher education institutions and commercial industries as well. Considering the higher educational institutions, the CIS will improve IT integration for educational institutions with their subsidiaries or with other institutions within the country and abroad in terms of educational management, teaching, learning, and research, including promoting international students’ academic integration, collaboration, and governance. This will prove an innovative strategy to support the modernization and large expansion of academic institutions. This will be considered IT-institutional alignment within a higher education context. This will also support achieving one of the sustainable development goals set by the United Nations: “Goal 4: ensure inclusive and quality education for all and promote lifelong learning”. However, the process of IT integration into higher educational institutions must be thoroughly evaluated, identifying the vital data access points. In this chapter, Section 1 provides an introduction, including the evolution of various database systems, data models, and the emergence of multidatabase systems and their importance. Section 2 discusses component integration services (CIS), OmniConnect and considering heterogeneous relational distributed local databases from the perspective of academics, Section 3 discusses the Sybase Adaptive Server Enterprise (ASE), Section 4 discusses the role of component integration services and OmniConnect of Sybase ASE under the Multidatabase System, Section 5 shows the database architectural framework, Section 6 provides an implementation overview of the global conceptual schema in the multidatabase system, Section 7 discusses query processing in the CIS, and finally, Section 8 concludes the chapter. The chapter will help our students a lot, as we have discussed well the evolution of databases and data models and the emergence of multidatabases. Since some additional useful information is cited, the source of information for each citation is properly mentioned in the references column. 展开更多
关键词 Relational database Component Integration Services OmniConnect MULTIdatabasE global Conceptual Schema Distributed database Local Conceptual Schema database Integration IT Integration Higher Education Commercial Industries HEIs
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海洋硬骨鱼类对海洋碳循环的影响研究现状
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作者 赵振方 陈新军 +2 位作者 刘必林 郭方 胡贯宇 《生态学报》 CAS CSCD 北大核心 2024年第20期8933-8943,共11页
海洋硬骨鱼类在全球碳循环中扮演着重要角色,其生理活动对海洋碳汇具有显著影响。研究回顾并总结了海洋硬骨鱼类对海洋碳汇影响的研究进展,分析了鱼类通过主动和被动运输机制对海洋碳循环的贡献,并整理了关于碳酸盐排泄的现有模型。研... 海洋硬骨鱼类在全球碳循环中扮演着重要角色,其生理活动对海洋碳汇具有显著影响。研究回顾并总结了海洋硬骨鱼类对海洋碳汇影响的研究进展,分析了鱼类通过主动和被动运输机制对海洋碳循环的贡献,并整理了关于碳酸盐排泄的现有模型。研究认为,海洋硬骨鱼类通过呼吸作用、垂直洄游和死亡沉降等过程,对海洋深层的碳储存具有重要作用。这些过程不仅与鱼类的代谢活动紧密相关,而且还受到水温、盐度、pH值等环境因素的影响。然而,当前对海洋硬骨鱼碳汇的定量估算有限,且缺乏系统性研究。研究强调了未来深入研究的必要性,包括全球范围内的鱼类固碳潜力评估、环境因素对鱼类固碳效率的影响、以及鱼类死亡沉降作为碳汇过程的评估。研究建议建立全球鱼类固碳数据库等基础平台,以促进国际合作并提高对鱼类在海洋碳循环中作用的科学认识。 展开更多
关键词 海洋硬骨鱼类 海洋碳汇 生理活动 环境因素 全球数据库
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全球主要开源数据库强震动记录的基本分布特征
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作者 肖裴渊 任叶飞 +4 位作者 吴玉娇 周宝峰 张亚军 吴华灯 温瑞智 《地震研究》 CSCD 北大核心 2024年第4期553-562,共10页
强震动数据是地震工程和工程地震领域研究的基础,为了便于高效选取强震动记录,基于以下全球强震动开源数据库:美国USGS、欧洲ESM、日本K-NET和KiK-net、墨西哥RAII-UNAM和新西兰GeoNet,收集整理5.0级以上地震的强震动记录40余万组,约15... 强震动数据是地震工程和工程地震领域研究的基础,为了便于高效选取强震动记录,基于以下全球强震动开源数据库:美国USGS、欧洲ESM、日本K-NET和KiK-net、墨西哥RAII-UNAM和新西兰GeoNet,收集整理5.0级以上地震的强震动记录40余万组,约150万条,通过震级、台站分布、场地条件、反应谱谱型等强震动基本信息对强震动记录进行筛选并分类,采用两套标准对场地进行了分类,对绝对加速度反应谱进行归一化,对比分析5个国家和地区的平均反应谱谱型的相似性与特殊性,结果表明:①美国强震动台站集中分布在西海岸与阿拉斯加地区,较硬的场地占比较高;②日本强震动台站分布密度最高,较软的场地占比较高;③给出了中、美两套规范下的强震动台站场地分类;④从震中距方面考虑,美国为近场强震动记录最为集中和丰富的国家;⑤不同国家和地区相同周期段绝对加速度反应谱具有明显的区域性差异。 展开更多
关键词 强震动记录 开源数据库 绝对加速度反应谱 场地分类
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A Web-Based Approach for the Efficient Management of Massive Multi-source 3D Models
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作者 ZHAO Qiansheng TANG Ruibing +1 位作者 PENG Mingjun GUO Mingwu 《Journal of Geodesy and Geoinformation Science》 CSCD 2024年第3期24-41,共18页
Effectively managing extensive,multi-source,and multi-level real-scene 3D models for responsive retrieval scheduling and rapid visualization in the Web environment is a significant challenge in the current development... Effectively managing extensive,multi-source,and multi-level real-scene 3D models for responsive retrieval scheduling and rapid visualization in the Web environment is a significant challenge in the current development of real-scene 3D applications in China.In this paper,we address this challenge by reorganizing spatial and temporal information into a 3D geospatial grid.It introduces the Global 3D Geocoding System(G_(3)DGS),leveraging neighborhood similarity and uniqueness for efficient storage,retrieval,updating,and scheduling of these models.A combination of G_(3)DGS and non-relational databases is implemented,enhancing data storage scalability and flexibility.Additionally,a model detail management scheduling strategy(TLOD)based on G_(3)DGS and an importance factor T is designed.Compared with mainstream commercial and open-source platforms,this method significantly enhances the loadable capacity of massive multi-source real-scene 3D models in the Web environment by 33%,improves browsing efficiency by 48%,and accelerates invocation speed by 40%. 展开更多
关键词 massive multi-source real-scene 3D model non-relational database global 3D geocoding system importance factor massive model management
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基于GBD数据库中国青光眼流行病学负担分析
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作者 高天雨 关徐涛 +1 位作者 刘瑞宝 杨稀瑞 《眼科新进展》 CAS 北大核心 2024年第5期382-386,390,共6页
目的下载全球疾病负担(GBD)数据库中中国青光眼的相关数据,分析中国青光眼的疾病流行病学负担,从而为中国青光眼防控提供理论依据。方法下载GBD(2019)数据库中患病人数、患病率、伤残调整寿命年(DALYs)/DALY率的相关数据,分析中国1990—... 目的下载全球疾病负担(GBD)数据库中中国青光眼的相关数据,分析中国青光眼的疾病流行病学负担,从而为中国青光眼防控提供理论依据。方法下载GBD(2019)数据库中患病人数、患病率、伤残调整寿命年(DALYs)/DALY率的相关数据,分析中国1990—2019年青光眼流行趋势及年龄、时期、性别趋势和青光眼与社会人口指数(SDI)之间的关系。结果2019年,中国青光眼粗患病人数位于全球首位,中国青光眼导致的DALYs位于全球第二。2019年,中国青光眼患病率位于全球高水平,患病人数为1990年的1.92倍,患病率及DALY率均持续上升;中国青光眼患病人数年龄趋势呈中间高、两头低形态,且男性高于女性,随着SDI的增长,年龄标化患病率和DALY率均呈现降低趋势,平均年度变化百分比均为负数。患病人数的年龄趋势呈现中间高、两边低的形态。随着SDI的增长,年龄标化患病率和DALY率整体呈现降低趋势,平均年度变化百分比均为负数。结论1990—2019年间,中国青光眼疾病负担显著上升,居全球前列,且与社会发展程度呈正相关。 展开更多
关键词 青光眼 中国 疾病负担 全球疾病负担数据库
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世界卫生组织药品不良反应数据库全球信号管理方法简述
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作者 彼得·希尔姆斯特伦姆 杰弗里·鲍林 +1 位作者 岳群英 G.尼克拉斯·诺伦 《中国药物警戒》 2024年第7期836-840,共5页
世界卫生组织(WHO)药品不良反应病例报告数据库(VigiBase)自1978年起由乌普萨拉监测中心(UMC)开发和维护。目前VigiBase保存着超过3900万份匿名的患者疑似药品和疫苗不良反应报告(截至2024年6月)。为支持世界卫生组织国际药物监测计划(W... 世界卫生组织(WHO)药品不良反应病例报告数据库(VigiBase)自1978年起由乌普萨拉监测中心(UMC)开发和维护。目前VigiBase保存着超过3900万份匿名的患者疑似药品和疫苗不良反应报告(截至2024年6月)。为支持世界卫生组织国际药物监测计划(WHO PIDM)成员国制定、实施和加强安全监测计划,UMC开发了多个系统、工具和方法,以促进VigiBase的使用。本文描述了6种vigi方法(vigiMethods):vigiGrade、vigiMatch、vigiRank、vigiPoint、vigiGroup和vigiVec。VigiBase数据来源依靠主动报告的药品不良反应,但药品不良反应漏报是一个主要问题。为提高大型数据库(如VigiBase)中病例处理的效率、质量和能力,人工智能增强方法正在不断发展,以满足管理日益增长的数据量需求。继续开发现有的和新的方法,将VigiBase和其他数据库中的报告内容转化为有价值的信息,对于全球所有国家的患者更安全地使用药物和疫苗至关重要。 展开更多
关键词 药品不良反应数据库 世界卫生组织 全球 不良反应 信号 安全 数据库 管理 方法
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PDMS GLOBAL异地协同设计在长岭项目中的应用 被引量:2
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作者 王艳艳 《企业技术开发》 2012年第6期66-68,共3页
随着总承包项目的增加,设计公司、总承包现场、业主之间的数据传输问题逐渐凸显。文章针对AVEVA GLOBAL软件,阐述了其在长岭项目中的应用过程,以提高公司的三维设计竞争力。
关键词 global 异地协同设计 数据库 同步
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Development of Global Geographical Coverage Area for Terrestrial Networks Internetworked with Leo Satellite Network
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作者 V. O. C. Eke A. N. Nzeako 《Communications and Network》 2014年第4期228-242,共15页
Network planning, analysis and design are an iterative process aimed at ensuring that a new network service meets the needs of subscribers and operators. During the initial start-up phase, coverage is the big issue an... Network planning, analysis and design are an iterative process aimed at ensuring that a new network service meets the needs of subscribers and operators. During the initial start-up phase, coverage is the big issue and coverage in telecommunications systems is related to the service area where a bare minimum access in the wireless network is possible. In order to guarantee visibility of at least one satellite above a certain satellite elevation, more satellites are required in the constellation to provide Global network services. Hence, the aim of this paper is to develop wide area network coverage for sparsely distributed earth stations in the world. A hybrid geometrical topology model using spherical coordinate framework was devised to provide wide area network coverage for sparsely distributed earth stations in the world. This topology model ensures Global satellite continuous network coverage for terrestrial networks. A computation of path lengths between any two satellites put in place to provide network services to selected cities in the world was carried out. A consideration of a suitable routing decision mechanism, routing protocols and algorithms were considered in the work while the shortest paths as well as the alternate paths between located nodes were computed. It was observed that a particular satellite with the central angle of 27&deg;can provide services into the diameter of the instantaneous coverage distance of 4081.3 Km which is typical of wide area network coverage. This implies that link-state database routing scheme can be applied, continuous global geographical coverage with minimum span, minimum traffic pattern and latency are guaranteed. Traffic handover rerouting strategies need further research. Also, traffic engineering resources such as channel capacity and bandwidth utilization schemes need to be investigated. Satellite ATM network architecture will benefit and needs further study. 展开更多
关键词 NETWORK Planning global NETWORK COVERAGE VISIBILITY Angle Link-State database ORTHOGONAL Route Path Dijkstra’s Algorithm
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荷兰学术数据库“走出去”的国际经验及启示 被引量:4
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作者 裴永刚 索煜祺 《编辑之友》 北大核心 2023年第3期107-112,共6页
学术数据库“走出去”承载了学术出版走向世界的重任,作为学术数据库强国的荷兰有诸多国际经验值得借鉴。文章梳理了荷兰学术数据库“走出去”的发展历程,指出其规模大、种类全,具有相当大的学术影响力和学术话语权。在此基础上,从政策... 学术数据库“走出去”承载了学术出版走向世界的重任,作为学术数据库强国的荷兰有诸多国际经验值得借鉴。文章梳理了荷兰学术数据库“走出去”的发展历程,指出其规模大、种类全,具有相当大的学术影响力和学术话语权。在此基础上,从政策法规与制度支持、内容与产品、国际运营策略与模式、人才与技术四方面分析了学术数据库“走出去”的荷兰经验,为我国学术数据库“走出去”提供参考。 展开更多
关键词 荷兰学术数据库 学术数据库“走出去” 数字出版
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MeteoRead: Client Software for Inserting Observed Atmospheric Data into MySQL<sub>TM</sub>Database and Downloading them into Different File Format
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作者 Beáta Szabó-Takács Tamás Takács Aleš Roček 《Journal of Software Engineering and Applications》 2021年第10期563-574,共12页
The investigation of the tendency of climate change and its effects on ecology, economy and sociology is essential for long term policy making. The long-term measurement of the physical and chemical properties of the ... The investigation of the tendency of climate change and its effects on ecology, economy and sociology is essential for long term policy making. The long-term measurement of the physical and chemical properties of the atmosphere with state-of-the-arts instruments provides high-quality data for these studies. The evaluated data are stored in really special file structures and formats that cannot be inserted in one common database. Moreover, the observed data usually available in ASCII format and the users sometimes need to convert them in other format. The file conversion is usually time consuming procedure and can contribute to the uncertainties. MeteoRead is a client database software that imports the observed atmospheric data e.g. wind direction, wind speed, aerosol particle concentration etc. and makes them available in different file formats, which are most commonly used in climate research. This Java<sup>TM</sup> based program applies the Structured Query Language (SQL) functions such as table creation on a database server, data or figures insertion into the table and data selection via Graphical User Interface. The selected data can be stored in NetCDF, HDF5, DataBase or TXT file formats and the figures can be available in PNG, JPG, JPNG, PDF or GIF file formats. The program was tested on Linux and Windows platforms with different Java<sup>TM</sup> Development Kit. The MeteoRead is planned to be developed to visualizing the annual, seasonal, monthly, daily or hourly average value of the selected data and to use the functionality of the SQL database to calculate various mathematical and statistical correlations. 展开更多
关键词 JavaTM Language MySQLTM databasE Atmospheric Data global Change
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金融分布式数据库异步全局索引研究
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作者 金磐石 李博涵 +3 位作者 秦小麟 邢磊 李晓栋 王进 《计算机科学与探索》 CSCD 北大核心 2023年第11期2784-2794,共11页
伴随移动支付的快速发展,传统的金融核心业务所使用的集中式数据库面临性能、可用性等方面的挑战。为此有研究者提出了采用计算和存储分离架构的分布式数据库解决思路,通过网络连接构建在物理上分散、逻辑上集中的分布式数据库管理系统... 伴随移动支付的快速发展,传统的金融核心业务所使用的集中式数据库面临性能、可用性等方面的挑战。为此有研究者提出了采用计算和存储分离架构的分布式数据库解决思路,通过网络连接构建在物理上分散、逻辑上集中的分布式数据库管理系统。全局索引是分布式数据库提升查询效率的重要手段,但当前的全局索引主要通过在传统网络中利用同步机制来实现。这种机制在金融数据管理的典型交易和批量导入数据场景下面临单表索引数量少、吞吐量降低、事务响应时间抖动等亟需解决的问题。为此,提出了一种基于分布式数据库的异步全局索引架构,通过新增MQ消息队列、分布式缓存,以及利用RDMA网络,实现一种满足金融典型场景需求的异步全局索引。为了验证有效性,与Oracle、CockroachDB在相同的场景下进行大量对比分析,实验结果表明,在金融核心业务数据的批量导入、交易等场景中,该方法的主要性能指标比现有方法提升60%以上,而对系统资源需求降低20%以上。 展开更多
关键词 分布式数据库 异步 全局索引 低时延 RDMA网络
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异构分布式数据库系统集成的研究与实现 被引量:35
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作者 胡彬华 李晓 梁剑 《计算机应用研究》 CSCD 北大核心 2002年第10期67-70,共4页
介绍了异构分布式数据库系统集成的现状、主要的技术问题 ;并介绍了异构分布式数据库系统———UPHDDB的分析。
关键词 异构分布式数据库系统 集成 全局数据字典 查询优化 ODBC
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国际主要温室气体排放数据集比较分析研究 被引量:47
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作者 曲建升 曾静静 张志强 《地球科学进展》 CAS CSCD 北大核心 2008年第1期47-54,共8页
温室气体排放数据集是国际上开展温室气体排放评价与减排责任谈判的数据基础。对国际上温室气体排放的数据集进行了细致的调研和分析,收集并较为全面深入地比较分析了美国能源信息管理局(EIA)数据集、世界资源研究所(WRI)数据集、美国... 温室气体排放数据集是国际上开展温室气体排放评价与减排责任谈判的数据基础。对国际上温室气体排放的数据集进行了细致的调研和分析,收集并较为全面深入地比较分析了美国能源信息管理局(EIA)数据集、世界资源研究所(WRI)数据集、美国橡树岭国家实验室CO2信息分析中心(CDIAC)数据集、联合国气候变化框架公约(UNFCCC)数据集和OECD国际能源署(IEA)数据集等5个全球尺度的国际主要温室气体数据集的主要信息。概括了这5个国际主要温室气体数据集的开发机构概况、分析了数据集的详细特征、定量比较了这些数据集的可用性与差异。 展开更多
关键词 全球变暖 气候政策 温室气体 数据 二氧化碳
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基于本体的异构数据库集成方法 被引量:11
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作者 张磊 夏士雄 牛强 《计算机工程与设计》 CSCD 北大核心 2007年第14期3299-3301,共3页
随着数据库种类的增多,在查询不同数据库时,经常碰到用户术语和数据库术语不匹配的问题。提出了一种基于本体理论的异构数据库集成方法,该方法利用了一个全局字典,建立各局部数据库的本体,通过中间件和局部查询代理处理用户请求,用他们... 随着数据库种类的增多,在查询不同数据库时,经常碰到用户术语和数据库术语不匹配的问题。提出了一种基于本体理论的异构数据库集成方法,该方法利用了一个全局字典,建立各局部数据库的本体,通过中间件和局部查询代理处理用户请求,用他们自己的术语(不精确查询)进行查询。给出了本体模型和查询处理算法以及原型系统的实现。 展开更多
关键词 本体 数据库集成 异构 模糊查询 全局字典
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基于分布对象Web的主流数据库集成系统 被引量:3
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作者 董传良 杨虹 +2 位作者 吕葵 钟华 张云涛 《计算机研究与发展》 EI CSCD 北大核心 2002年第4期458-465,共8页
面向新一代的分布式对象Web体系结构,将全局数据库技术、全局数据库事务管理技术、主流数据库对象化组件技术和先进的CORBA对象技术综合成一体.在支持异构分布式系统的CORBA机制、全局数据库模式、全局查询语言的定义、... 面向新一代的分布式对象Web体系结构,将全局数据库技术、全局数据库事务管理技术、主流数据库对象化组件技术和先进的CORBA对象技术综合成一体.在支持异构分布式系统的CORBA机制、全局数据库模式、全局查询语言的定义、语法和语义分析、查询优化、主流数据库的对象化表示、事务的管理、并发控制、安全管理、全局事务的完整性处理、主流数据库的集成工具、多数据库系统的管理和维护策略等方面,针对实用化的目标开展研究并加以实现. 展开更多
关键词 分布对象 WEB 数据库集成系统 全局事务管理 组件
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快速挖掘全局频繁项目集 被引量:35
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作者 杨明 孙志挥 吉根林 《计算机研究与发展》 EI CSCD 北大核心 2003年第4期620-626,共7页
分布式环境中 ,全局频繁项目集的挖掘是数据挖掘中最重要的研究课题之一 传统的全局频繁项目集挖掘算法采用Apriori算法框架 ,须多遍扫描数据库并产生大量的候选项目集 ,且通过传送局部频繁项目集求全局频繁项目集的网络通信代价高 为... 分布式环境中 ,全局频繁项目集的挖掘是数据挖掘中最重要的研究课题之一 传统的全局频繁项目集挖掘算法采用Apriori算法框架 ,须多遍扫描数据库并产生大量的候选项目集 ,且通过传送局部频繁项目集求全局频繁项目集的网络通信代价高 为此 ,提出了一种分布数据库的全局频繁项目集快速挖掘算法———FMAGF FMAGF算法采用传送条件频繁模式树或条件模式基来挖掘全局频繁项目集 ,可有效地减小网络通信量 ,提高全局频繁项目集挖掘效率 展开更多
关键词 数据挖掘 全局频繁项目集 频繁模式树 快速挖掘算法 布尔型关联规则 数据库 APRIORI算法
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GBD数据库的数据提取方法与流程 被引量:51
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作者 屈彦 王天一 +2 位作者 杨津 张军 吕军 《中国循证心血管医学杂志》 2019年第9期1043-1046,共4页
疾病对人群健康的危害始终是人们普遍关注的问题,疾病负担是指疾病、伤残以及早逝对生命健康、社会经济方面的损失和影响,准确掌握全球疾病负担的现状和发展,对促进人类健康和经济社会发展具有重要意义。GBD数据库是了解全球疾病负担最... 疾病对人群健康的危害始终是人们普遍关注的问题,疾病负担是指疾病、伤残以及早逝对生命健康、社会经济方面的损失和影响,准确掌握全球疾病负担的现状和发展,对促进人类健康和经济社会发展具有重要意义。GBD数据库是了解全球疾病负担最重要的数据库,它涵盖了最全面的疾病、风险、死亡及与疾病相关的伤残对健康造成的负担,因此掌握GBD数据库的使用方法非常必要。该数据库是一个开放的状态,感兴趣的研究者可以申请其中的数据进行相关研究,本文旨在对该数据库的申请方式以及数据的提取方法进行介绍。 展开更多
关键词 全球疾病负担 GBD数据库 申请 数据提取
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