The time-history responses of the surface were obtained for a linear elastic half-plane including regularly distributed enormous embedded circular cavities subjected to propagating obliquely incident plane SH-waves. A...The time-history responses of the surface were obtained for a linear elastic half-plane including regularly distributed enormous embedded circular cavities subjected to propagating obliquely incident plane SH-waves. An advanced numerical approach named half-plane time-domain boundary element method（BEM）, which only located the meshes around the cavities, was used to create the model. By establishing the modified boundary integral equation（BIE）independently for each cavity and forming the matrices, the final coupled equation was solved step-by-step in the timedomain to obtain the boundary values. The responses were developed for a half-plane with 512 cavities. The amplification patterns were also obtained to illustrate the frequencydomain responses for some cases. According to the results,the presence of enormous cavities affects the scattering and diffraction of the waves arrived to the surface. The introduced method can be recommended for geotechnical/mechanical engineers to model structures in the fields of earthquake engineering and composite materials.展开更多
分析家庭宽带PON(passive optical network,无源光网络)接入网络中OLT(optical line terminal,光线路终端)用户的承载能力,计算PON端口接入距离。依据理论计算,结合PON实例,给出了PON结构优化的参考方案。同时,在考虑对现网资源节约的...分析家庭宽带PON(passive optical network,无源光网络)接入网络中OLT(optical line terminal,光线路终端)用户的承载能力,计算PON端口接入距离。依据理论计算,结合PON实例,给出了PON结构优化的参考方案。同时,在考虑对现网资源节约的前提下,通过对OLT承载用户数的分裂及用户接入距离的优化,来提升用户感知度。展开更多
光纤到户(fiber to the home,FTTH)是以光信号为传输载体的通信方式,将光纤从局端直接连通至用户家中,并将光网络单元安装在用户家,为用户提供更高的带宽,这种通信方式可以适应更多的使用环境,减少了供电需求,且安装和维护方便。为解决...光纤到户(fiber to the home,FTTH)是以光信号为传输载体的通信方式,将光纤从局端直接连通至用户家中,并将光网络单元安装在用户家,为用户提供更高的带宽,这种通信方式可以适应更多的使用环境,减少了供电需求,且安装和维护方便。为解决现代通信网“最后一公里”的接入问题,分析了3种FTTH接入技术,并针对无源光网络(passive optical network,PON)接入技术进行了具体应用分析,包括不同场景一级、二级分光模式的使用以及不同分光模式下光线路终端(optical line terminal,OLT)、分光分纤箱与分光器(passive optical splitter,POS)的位置设置等,以期为相关工程和相关人员提供参考。展开更多
文摘The time-history responses of the surface were obtained for a linear elastic half-plane including regularly distributed enormous embedded circular cavities subjected to propagating obliquely incident plane SH-waves. An advanced numerical approach named half-plane time-domain boundary element method（BEM）, which only located the meshes around the cavities, was used to create the model. By establishing the modified boundary integral equation（BIE）independently for each cavity and forming the matrices, the final coupled equation was solved step-by-step in the timedomain to obtain the boundary values. The responses were developed for a half-plane with 512 cavities. The amplification patterns were also obtained to illustrate the frequencydomain responses for some cases. According to the results,the presence of enormous cavities affects the scattering and diffraction of the waves arrived to the surface. The introduced method can be recommended for geotechnical/mechanical engineers to model structures in the fields of earthquake engineering and composite materials.
文摘分析家庭宽带PON(passive optical network,无源光网络)接入网络中OLT(optical line terminal,光线路终端)用户的承载能力,计算PON端口接入距离。依据理论计算,结合PON实例,给出了PON结构优化的参考方案。同时,在考虑对现网资源节约的前提下,通过对OLT承载用户数的分裂及用户接入距离的优化,来提升用户感知度。
文摘光纤到户(fiber to the home,FTTH)是以光信号为传输载体的通信方式,将光纤从局端直接连通至用户家中,并将光网络单元安装在用户家,为用户提供更高的带宽,这种通信方式可以适应更多的使用环境,减少了供电需求,且安装和维护方便。为解决现代通信网“最后一公里”的接入问题,分析了3种FTTH接入技术,并针对无源光网络(passive optical network,PON)接入技术进行了具体应用分析,包括不同场景一级、二级分光模式的使用以及不同分光模式下光线路终端(optical line terminal,OLT)、分光分纤箱与分光器(passive optical splitter,POS)的位置设置等,以期为相关工程和相关人员提供参考。
