要提供高质量的室内位置服务,必须首先获得用户在室内的准确位置。由于非视距传播、多径传播、环境变化等因素的影响,传统的GPS等定位技术并不适用于室内环境。但逐渐密集的无线局域网(wireless local area network,WLAN)为实现室内定...要提供高质量的室内位置服务,必须首先获得用户在室内的准确位置。由于非视距传播、多径传播、环境变化等因素的影响,传统的GPS等定位技术并不适用于室内环境。但逐渐密集的无线局域网(wireless local area network,WLAN)为实现室内定位提供了良好的环境。本文从NNSS-AVG定位算法出发,大大的优化了其定位精度,从而适应现代人们生活的需要。展开更多
针对组网导航系统(networked navigation systems,NNSs)中节点高速移动、能量受限及通信时滞的问题,融合了基于移动汇聚节点的交叉路由树构建及链式分簇相结合的路由协议(cross routing tree construction based on mobile sink and cha...针对组网导航系统(networked navigation systems,NNSs)中节点高速移动、能量受限及通信时滞的问题,融合了基于移动汇聚节点的交叉路由树构建及链式分簇相结合的路由协议(cross routing tree construction based on mobile sink and chain clustering,CRTCC),设计了一种基于节点分级的跨层媒介访问控制协议(medium access control protocol based on graded nodes,GN-MAC)。GN-MAC采取了基于竞争的媒介访问方式,结合CRTCC协议特点定义GN-MAC包格式并完成具有多级别节点的自适应虚拟分簇,同时设计了改进型节点移动性检测算法,作出了最优簇间切换决策,提出了基于优先级的竞争机制以及多信道通信机制。最后通过算例仿真,验证了GN-MAC在节点高速移动和多移动节点情况下,时滞和能耗得到了有效的控制。展开更多
Academic literacy is the fundamental quality that scholars should possess in order to get socialized in their disciplinary communities, of which academic writing is one of the most important aspects. This article atte...Academic literacy is the fundamental quality that scholars should possess in order to get socialized in their disciplinary communities, of which academic writing is one of the most important aspects. This article attempts to summarize some common features of academic writing and the skills and background knowledge that are essential for successful writing. The next part focuses on the possible challenges that academic writing may pose on Chinese overseas students as they try to meet the requirements of the Western discourse communities. In the last part, it provides some recommendations to those who intend to study abroad and concludes that for both native and non-native speakers the learning of academic writing is a lifelong process of endless confliction and negotiation.展开更多
文摘要提供高质量的室内位置服务,必须首先获得用户在室内的准确位置。由于非视距传播、多径传播、环境变化等因素的影响,传统的GPS等定位技术并不适用于室内环境。但逐渐密集的无线局域网(wireless local area network,WLAN)为实现室内定位提供了良好的环境。本文从NNSS-AVG定位算法出发,大大的优化了其定位精度,从而适应现代人们生活的需要。
文摘针对组网导航系统(networked navigation systems,NNSs)中节点高速移动、能量受限及通信时滞的问题,融合了基于移动汇聚节点的交叉路由树构建及链式分簇相结合的路由协议(cross routing tree construction based on mobile sink and chain clustering,CRTCC),设计了一种基于节点分级的跨层媒介访问控制协议(medium access control protocol based on graded nodes,GN-MAC)。GN-MAC采取了基于竞争的媒介访问方式,结合CRTCC协议特点定义GN-MAC包格式并完成具有多级别节点的自适应虚拟分簇,同时设计了改进型节点移动性检测算法,作出了最优簇间切换决策,提出了基于优先级的竞争机制以及多信道通信机制。最后通过算例仿真,验证了GN-MAC在节点高速移动和多移动节点情况下,时滞和能耗得到了有效的控制。
文摘Academic literacy is the fundamental quality that scholars should possess in order to get socialized in their disciplinary communities, of which academic writing is one of the most important aspects. This article attempts to summarize some common features of academic writing and the skills and background knowledge that are essential for successful writing. The next part focuses on the possible challenges that academic writing may pose on Chinese overseas students as they try to meet the requirements of the Western discourse communities. In the last part, it provides some recommendations to those who intend to study abroad and concludes that for both native and non-native speakers the learning of academic writing is a lifelong process of endless confliction and negotiation.
