对传感器产生的语义数据流执行复杂推理的能力,最近已成为语义网社区中的重要研究领域,而目前大多数RDF流处理系统是以SPARQL(W3C标准RDF查询语言)为基础实现的,但这些引擎在捕获复杂的用户需求和处理复杂的推理任务方面存在局限性.针...对传感器产生的语义数据流执行复杂推理的能力,最近已成为语义网社区中的重要研究领域,而目前大多数RDF流处理系统是以SPARQL(W3C标准RDF查询语言)为基础实现的,但这些引擎在捕获复杂的用户需求和处理复杂的推理任务方面存在局限性.针对此问题,本文结合并扩展了回答集编程(Answer Set Programing,ASP)技术用于对RDF流进行连续的处理.为了验证本方法的有效性,首先以智能家居本体为实验对象,并分析传感器设备间的共有特性及复杂事件以构建本体库;然后基于本体库产生实例对象,并通过中间件产生RDF数据流;接下来通过扩展ASP,充分利用其表达和推理能力以减少推理时间,并设计了RDF流的窗口划分策略等,然后根据用户的请求,选择性地进行静态知识库加载等;最后通过实验与Sparkwave和Laser进行对比,证明了该方法在延迟和内存上的性能优势.展开更多
A generalized parallel-plate dielectric waveguide(G-PPDW)is proposed as a new guiding medium for terahertz wave.A theoretical analysis of the transmission characteristics for the TE modes of this generalized structure...A generalized parallel-plate dielectric waveguide(G-PPDW)is proposed as a new guiding medium for terahertz wave.A theoretical analysis of the transmission characteristics for the TE modes of this generalized structure is performed.Equations are presented for the field components,dispersion,power ratio,transmission loss and characteristic impedance as functions of the operating frequencies,dimensions and material constants.In the case of the lowest-order mode TE10,design curves covering frequencies and dimensions for the given material constants in the THz region are presented.The theoretical results of transmission characteristics obtained from these equations are verified by the finite-element method with a good agreement.The investigation results show that by selecting proper dimensions and dielectric materials,G-PPDW can be used to guide THz waves efficiently with high power confinement and low attenuation.These outstanding properties may open up a way to many important applications for THz integrated circuits and systems.展开更多
文摘对传感器产生的语义数据流执行复杂推理的能力,最近已成为语义网社区中的重要研究领域,而目前大多数RDF流处理系统是以SPARQL(W3C标准RDF查询语言)为基础实现的,但这些引擎在捕获复杂的用户需求和处理复杂的推理任务方面存在局限性.针对此问题,本文结合并扩展了回答集编程(Answer Set Programing,ASP)技术用于对RDF流进行连续的处理.为了验证本方法的有效性,首先以智能家居本体为实验对象,并分析传感器设备间的共有特性及复杂事件以构建本体库;然后基于本体库产生实例对象,并通过中间件产生RDF数据流;接下来通过扩展ASP,充分利用其表达和推理能力以减少推理时间,并设计了RDF流的窗口划分策略等,然后根据用户的请求,选择性地进行静态知识库加载等;最后通过实验与Sparkwave和Laser进行对比,证明了该方法在延迟和内存上的性能优势.
基金Supported in part by the Fundamental Research Funds for the Central Universities(No 103.1.2E022050205)the Key Lab Fund from National Key Laboratory of Monolithic Integrated Circuits and Modules,and the Fund under Grant No 9140A01020209DZ0203.
文摘A generalized parallel-plate dielectric waveguide(G-PPDW)is proposed as a new guiding medium for terahertz wave.A theoretical analysis of the transmission characteristics for the TE modes of this generalized structure is performed.Equations are presented for the field components,dispersion,power ratio,transmission loss and characteristic impedance as functions of the operating frequencies,dimensions and material constants.In the case of the lowest-order mode TE10,design curves covering frequencies and dimensions for the given material constants in the THz region are presented.The theoretical results of transmission characteristics obtained from these equations are verified by the finite-element method with a good agreement.The investigation results show that by selecting proper dimensions and dielectric materials,G-PPDW can be used to guide THz waves efficiently with high power confinement and low attenuation.These outstanding properties may open up a way to many important applications for THz integrated circuits and systems.
