目前空间数据网格中的访问权限控制基本是采用的设置用户角色和空间数据分级映射的机制,不能满足开放网格环境中的访问主体属性多样化和访问数据细粒度控制的要求。针对该问题,研究并提出了一种基于属性的空间数据安全访问机制。提出了...目前空间数据网格中的访问权限控制基本是采用的设置用户角色和空间数据分级映射的机制,不能满足开放网格环境中的访问主体属性多样化和访问数据细粒度控制的要求。针对该问题,研究并提出了一种基于属性的空间数据安全访问机制。提出了基于ABAC(attribute based access control)的目标用户、空间数据、网格环境的属性描述模型;在XACML(extensible access control markup language)的基础上,设计了完整的基于属性的空间数据访问策略、框架和流程。通过该项目的应用,表明了该机制能够有效满足空间数据网格访问控制要求。展开更多
To manipulate the heterogeneous and distributed data better in the data grid,a dataspace management framework for grid data is proposed based on in-depth research on grid technology.Combining technologies in dataspace...To manipulate the heterogeneous and distributed data better in the data grid,a dataspace management framework for grid data is proposed based on in-depth research on grid technology.Combining technologies in dataspace management,such as data model iDM and query language iTrails,with the grid data access middleware OGSA-DAI,a grid dataspace management prototype system is built,in which tasks like data accessing,Abstraction,indexing,services management and answer-query are implemented by the OGSA-DAI workflows.Experimental results show that it is feasible to apply a dataspace management mechanism to the grid environment.Dataspace meets the grid data management needs in that it hides the heterogeneity and distribution of grid data and can adapt to the dynamic characteristics of the grid.The proposed grid dataspace management provides a new method for grid data management.展开更多
New challenges are emerging in fine-scale air quality modeling in China due to a lack of high-resolution emission maps.Currently,only a few emission sources have accurate geographic locations(point sources),while a la...New challenges are emerging in fine-scale air quality modeling in China due to a lack of high-resolution emission maps.Currently,only a few emission sources have accurate geographic locations(point sources),while a large part of sources,including industrial plants,are estimated as provincial totals(area sources)and spatially disaggregated onto grid cells based on proxies;this approach is reasonable to some extent but is highly questionable at fine spatial resolutions.Here,we compile a new comprehensive point source database that includes nearly 100,000 industrial facilities in China.We couple it with the frame of Multi-resolution Emission Inventory for China(MEIC),estimate point source emissions,combine point and area sources,and finally map China’s anthropogenic emissions of 2013 at the spatial resolution of 30’’*30’’(~1 km).Consequently,the percentages of point source emissions in the total emissions increase from less than 30%in the MEIC up to a maximum of 84%for SO_(2)in 2013.The new point source-based emission maps show the uncoupled distribution of emissions and populations in space at fine spatial scales,however,such a pattern cannot be reproduced by any spatial proxy used in the conventional emissions mapping.This new accurate high-resolution emission mapping approach reduces the modeled biases of air pollutant concentrations in the densely populated areas compared to the raw MEIC inventory,thus improving the assessment of population exposure.展开更多
文摘目前空间数据网格中的访问权限控制基本是采用的设置用户角色和空间数据分级映射的机制,不能满足开放网格环境中的访问主体属性多样化和访问数据细粒度控制的要求。针对该问题,研究并提出了一种基于属性的空间数据安全访问机制。提出了基于ABAC(attribute based access control)的目标用户、空间数据、网格环境的属性描述模型;在XACML(extensible access control markup language)的基础上,设计了完整的基于属性的空间数据访问策略、框架和流程。通过该项目的应用,表明了该机制能够有效满足空间数据网格访问控制要求。
文摘To manipulate the heterogeneous and distributed data better in the data grid,a dataspace management framework for grid data is proposed based on in-depth research on grid technology.Combining technologies in dataspace management,such as data model iDM and query language iTrails,with the grid data access middleware OGSA-DAI,a grid dataspace management prototype system is built,in which tasks like data accessing,Abstraction,indexing,services management and answer-query are implemented by the OGSA-DAI workflows.Experimental results show that it is feasible to apply a dataspace management mechanism to the grid environment.Dataspace meets the grid data management needs in that it hides the heterogeneity and distribution of grid data and can adapt to the dynamic characteristics of the grid.The proposed grid dataspace management provides a new method for grid data management.
基金supported by the National Natural Science Foundation of China(91744310,41625020 and 41921005)the National Research Program for Key Issues in Air Pollution Control(DQGG0201)。
文摘New challenges are emerging in fine-scale air quality modeling in China due to a lack of high-resolution emission maps.Currently,only a few emission sources have accurate geographic locations(point sources),while a large part of sources,including industrial plants,are estimated as provincial totals(area sources)and spatially disaggregated onto grid cells based on proxies;this approach is reasonable to some extent but is highly questionable at fine spatial resolutions.Here,we compile a new comprehensive point source database that includes nearly 100,000 industrial facilities in China.We couple it with the frame of Multi-resolution Emission Inventory for China(MEIC),estimate point source emissions,combine point and area sources,and finally map China’s anthropogenic emissions of 2013 at the spatial resolution of 30’’*30’’(~1 km).Consequently,the percentages of point source emissions in the total emissions increase from less than 30%in the MEIC up to a maximum of 84%for SO_(2)in 2013.The new point source-based emission maps show the uncoupled distribution of emissions and populations in space at fine spatial scales,however,such a pattern cannot be reproduced by any spatial proxy used in the conventional emissions mapping.This new accurate high-resolution emission mapping approach reduces the modeled biases of air pollutant concentrations in the densely populated areas compared to the raw MEIC inventory,thus improving the assessment of population exposure.
