简要介绍了OLAP的概念和特点;从OLAP最新概念和技术等方面,解释了微软SQL Server 2005中统一维度模型;研究了微软现代OLAP搭建方法与传统搭建方法的差异;通过基于企业销售数据多维数据集的OLAP实例,说明了微软最新OLAP的设计概念的可行...简要介绍了OLAP的概念和特点;从OLAP最新概念和技术等方面,解释了微软SQL Server 2005中统一维度模型;研究了微软现代OLAP搭建方法与传统搭建方法的差异;通过基于企业销售数据多维数据集的OLAP实例,说明了微软最新OLAP的设计概念的可行性,有助于企业方便快捷地建立自已的分析决策支持平台。展开更多
下一个版本的Analysis Service(分析服务)在一个维度模型——统一维度模型(UDM)中结合了传统的基于OLAP分析和关系型报告的优点，满足了两者的需求集合，将会随着SQL Server Yukon一起发布。与直接访问关系数据库相比，OLAP技术为分析...下一个版本的Analysis Service(分析服务)在一个维度模型——统一维度模型(UDM)中结合了传统的基于OLAP分析和关系型报告的优点，满足了两者的需求集合，将会随着SQL Server Yukon一起发布。与直接访问关系数据库相比，OLAP技术为分析型用户提供了很多方便。OLAP的维度数据模型让理解、浏览和研究数据变得容易。通过OLAP对聚合数据的预计算可以让一些特殊的查询获得较快的响应时间，即使是对大量数据进行操作。展开更多
We introduce a non-uniform gravity-like force field to control the granular flow state in a quasi-one- dimensional system, and study the system by the molecular dynamics simulation. We find that the granular flow unde...We introduce a non-uniform gravity-like force field to control the granular flow state in a quasi-one- dimensional system, and study the system by the molecular dynamics simulation. We find that the granular flow under non-uniform force field can be well described by a density wave with fixed time period if a fixed partiele number condition is used. The base frequency of the density wave does not depend on the position of the flow, while both the average density and oseillation amplitude of the flow vary continuously with the position. The formation of the density wave results from the aggregation of the granules in the decelerated region and the feed-back mechanism in the fixed particle number condition.展开更多
文摘简要介绍了OLAP的概念和特点;从OLAP最新概念和技术等方面,解释了微软SQL Server 2005中统一维度模型;研究了微软现代OLAP搭建方法与传统搭建方法的差异;通过基于企业销售数据多维数据集的OLAP实例,说明了微软最新OLAP的设计概念的可行性,有助于企业方便快捷地建立自已的分析决策支持平台。
文摘下一个版本的Analysis Service(分析服务)在一个维度模型——统一维度模型(UDM)中结合了传统的基于OLAP分析和关系型报告的优点，满足了两者的需求集合，将会随着SQL Server Yukon一起发布。与直接访问关系数据库相比，OLAP技术为分析型用户提供了很多方便。OLAP的维度数据模型让理解、浏览和研究数据变得容易。通过OLAP对聚合数据的预计算可以让一些特殊的查询获得较快的响应时间，即使是对大量数据进行操作。
基金Supported by the National Basic Research Program of China under Grant No.2009CB930800by the National Natural Science Foundation of China under Grant Nos.10875166 and 11274355
文摘We introduce a non-uniform gravity-like force field to control the granular flow state in a quasi-one- dimensional system, and study the system by the molecular dynamics simulation. We find that the granular flow under non-uniform force field can be well described by a density wave with fixed time period if a fixed partiele number condition is used. The base frequency of the density wave does not depend on the position of the flow, while both the average density and oseillation amplitude of the flow vary continuously with the position. The formation of the density wave results from the aggregation of the granules in the decelerated region and the feed-back mechanism in the fixed particle number condition.
