Metadata prefetching and data placement play a critical role in enhancing access performance for file systems operating over wide-area networks.However,developing effective strategies for metadata prefetching in envir...Metadata prefetching and data placement play a critical role in enhancing access performance for file systems operating over wide-area networks.However,developing effective strategies for metadata prefetching in environments with concurrent workloads and for data placement across distributed networks remains a significant challenge.This study introduces novel and efficient methodologies for metadata prefetching and data placement,leveraging fine-grained control of prefetching strategies and variable-sized data fragment writing to optimize the I/O bandwidth of distributed file systems.The proposed metadata prefetching technique employs dynamic workload analysis to identify dominant workload patterns and adaptively refines prefetching policies,thereby boosting metadata access efficiency under concurrent scenarios.Meanwhile,the data placement strategy improves write performance by storing data fragments locally within the nearest data center and transmitting only the fragment location metadata to the remote data center hosting the original file.Experimental evaluations using real-world system traces demonstrate that the proposed approaches reduce metadata access times by up to 33.5%and application data access times by 17.19%compared to state-of-the-art techniques.展开更多
An ontology and metadata for online learning resource repository management is constructed. First, based on the analysis of the use-case diagram, the upper ontology is illustrated which includes resource library ontol...An ontology and metadata for online learning resource repository management is constructed. First, based on the analysis of the use-case diagram, the upper ontology is illustrated which includes resource library ontology and user ontology, and evaluated from its function and implementation; then the corresponding class diagram, resource description framework （RDF） schema and extensible markup language （XML） schema are given. Secondly, the metadata for online learning resource repository management is proposed based on the Dublin Core Metadata Initiative and the IEEE Learning Technologies Standards Committee Learning Object Metadata Working Group. Finally, the inference instance is shown, which proves the validity of ontology and metadata in online learning resource repository management.展开更多
[Objective] To study the information description of vegetable planting metadata model. [Method] On the basis of analyzing the data involved in every as- pect of vegetable planting, this paper put forward description s...[Objective] To study the information description of vegetable planting metadata model. [Method] On the basis of analyzing the data involved in every as- pect of vegetable planting, this paper put forward description schemes of vegetable planting metadata and constructed vegetable planting metadata model by the means of XML/XML schema. [Result] Metadata model of vegetable planting was established, and information description of vegetable planting metadata model was realized by the using of XML Schema. The whole metadata model consists of 7 first-class classifica- tions, including more than 800 information description points which could completely record vegetable planting-related information. [Conclusion] Standards for data collec- tion, management and sharing were provided for the agriculture applications in indus- tries like GAP management of vegetable planting, facility vegetable, food quality traceability, etc.展开更多
metadata是“关于数据的数据”,本文介绍了 m etadata的基本情况 ,并对 HTML 和 XML 环境的几个 m eta-data规范进行了论述 (包括 Dublin core,PICS,Web Collections,CDF ,MCF及 RDF)。由于 metadata在 Internet信息资源的组织和发现方...metadata是“关于数据的数据”,本文介绍了 m etadata的基本情况 ,并对 HTML 和 XML 环境的几个 m eta-data规范进行了论述 (包括 Dublin core,PICS,Web Collections,CDF ,MCF及 RDF)。由于 metadata在 Internet信息资源的组织和发现方面起着非常重要的作用 ,作者呼吁国人应当加强对 metadata的研究。展开更多
基金funded by the National Natural Science Foundation of China under Grant No.62362019the Hainan Provincial Natural Science Foundation of China under Grant No.624RC482.
文摘Metadata prefetching and data placement play a critical role in enhancing access performance for file systems operating over wide-area networks.However,developing effective strategies for metadata prefetching in environments with concurrent workloads and for data placement across distributed networks remains a significant challenge.This study introduces novel and efficient methodologies for metadata prefetching and data placement,leveraging fine-grained control of prefetching strategies and variable-sized data fragment writing to optimize the I/O bandwidth of distributed file systems.The proposed metadata prefetching technique employs dynamic workload analysis to identify dominant workload patterns and adaptively refines prefetching policies,thereby boosting metadata access efficiency under concurrent scenarios.Meanwhile,the data placement strategy improves write performance by storing data fragments locally within the nearest data center and transmitting only the fragment location metadata to the remote data center hosting the original file.Experimental evaluations using real-world system traces demonstrate that the proposed approaches reduce metadata access times by up to 33.5%and application data access times by 17.19%compared to state-of-the-art techniques.
基金The Advanced University Action Plan of the Minis-try of Education of China (2004XD-03).
文摘An ontology and metadata for online learning resource repository management is constructed. First, based on the analysis of the use-case diagram, the upper ontology is illustrated which includes resource library ontology and user ontology, and evaluated from its function and implementation; then the corresponding class diagram, resource description framework （RDF） schema and extensible markup language （XML） schema are given. Secondly, the metadata for online learning resource repository management is proposed based on the Dublin Core Metadata Initiative and the IEEE Learning Technologies Standards Committee Learning Object Metadata Working Group. Finally, the inference instance is shown, which proves the validity of ontology and metadata in online learning resource repository management.
基金Supported by the Youth Innovation Fund of Fujian Academy of Agricultural Science(2010QB-17)the Science and Technology Bureau Project of Fujian Province(2008S1001)the Financial Special Project of Fujian Province(STIF-Y07)~~
文摘[Objective] To study the information description of vegetable planting metadata model. [Method] On the basis of analyzing the data involved in every as- pect of vegetable planting, this paper put forward description schemes of vegetable planting metadata and constructed vegetable planting metadata model by the means of XML/XML schema. [Result] Metadata model of vegetable planting was established, and information description of vegetable planting metadata model was realized by the using of XML Schema. The whole metadata model consists of 7 first-class classifica- tions, including more than 800 information description points which could completely record vegetable planting-related information. [Conclusion] Standards for data collec- tion, management and sharing were provided for the agriculture applications in indus- tries like GAP management of vegetable planting, facility vegetable, food quality traceability, etc.
文摘metadata是“关于数据的数据”,本文介绍了 m etadata的基本情况 ,并对 HTML 和 XML 环境的几个 m eta-data规范进行了论述 (包括 Dublin core,PICS,Web Collections,CDF ,MCF及 RDF)。由于 metadata在 Internet信息资源的组织和发现方面起着非常重要的作用 ,作者呼吁国人应当加强对 metadata的研究。
