跟踪移动用户同时减少信令开销是通信系统位置管理研究中重要的方面。跟踪区列表是LTE系统中新引入的概念,它由多个跟踪区构成用来减少位置管理信令开销。受生活、工作、学习方面的影响,大部分用户具有固定的移动方式。提出了一种基于...跟踪移动用户同时减少信令开销是通信系统位置管理研究中重要的方面。跟踪区列表是LTE系统中新引入的概念,它由多个跟踪区构成用来减少位置管理信令开销。受生活、工作、学习方面的影响,大部分用户具有固定的移动方式。提出了一种基于跟踪区关联性的跟踪区列表设计方法,它通过从用户历史移动路径中获取各跟踪区之间的关联性并建立各跟踪区的关联表,当跟踪区更新消息发生时,网络获取该消息中提供的上次访问跟踪区和用户当前所在跟踪区结合关联表进行跟踪区列表设计。该方法能够随不同上次访问跟踪区动态分配跟踪区列表,特别适用于大规模网络中。最后运用里斯本城镇网络数据,实验比较了基于跟踪区关联性的跟踪区列表设计方法和rule of thumb设计方法在一整天的信令开销。结果显示该方法在减少位置管理信令开销方面性能至少提升了11.5%。展开更多
为了克服2G和3G移动通信网络位置管理方案的缺陷,4G长期演进(Long Term Evolution,LTE)采用了基于跟踪区列表(Tracking Area List,TAL)的位置管理方案。基于TAL的位置管理方案的性能取决于TAL分配方案。考虑到本地移动设备(User Equipme...为了克服2G和3G移动通信网络位置管理方案的缺陷,4G长期演进(Long Term Evolution,LTE)采用了基于跟踪区列表(Tracking Area List,TAL)的位置管理方案。基于TAL的位置管理方案的性能取决于TAL分配方案。考虑到本地移动设备(User Equipment,UE)的活动区域相对固定,该文提出一种嵌入式马尔科夫链模型,用于分析本地UE的基于TAL的位置管理方案的信令开销。推导得到位置更新开销和寻呼开销的数学公式。利用这些公式,可搜索得到能使信令开销最低化的最佳TAL分配方案。展开更多
Aim Aiming at the position tracking control for valve controlled motor electrohydraulic proportional servo systems mainly driving the static load torque, the tracking performance was studied in the presence of the v...Aim Aiming at the position tracking control for valve controlled motor electrohydraulic proportional servo systems mainly driving the static load torque, the tracking performance was studied in the presence of the variable gain and deadzone. Methods On the basis of conventional composite control with the deadzone compensation method, a comprehensive control approach with the deadzone and self adjusting feedforward compensation was proposed. Results Experimental results showed that the good tracking performance was achieved for the sinusoidal and constant velocity position tracking under a wide variations of load torque. Conclusion The position tracking accuracy for valve controlled motor electrohydraulic proportional servo systems has been solved by using the comprehensive control approach with the deadzone and self adjusting feedforward compensation.展开更多
A novel Snake model with region information is proposed to detect and track moving objects. Generally, the region-information-based approach is sensitive to illumination changes and small movement in the background, w...A novel Snake model with region information is proposed to detect and track moving objects. Generally, the region-information-based approach is sensitive to illumination changes and small movement in the background, while the edge-information-based approach often obtains incorrect results for ambiguous images. The two types of information are introduced in computing the image force. Edge-information-based features make the algorithm fast and robust, and region information makes the active confour energy function obtains correct results for ambiguous images. Furthermore, an automatic contour initialization method using double difference images is given to meet the requirement of video sequence tracking. Meanwhile, a simple forecast section is added to estimate the position of the contour in the algorithm so that it can improve the convergence speed of the active contour. Experimental results show that the computation time of the algorithm is less than 0.1 s/frame. And it can be applied to a real-time system.展开更多
This paper proposes a block Mean-Shift algorithm based on target real-time update and LBP texture features, through the target update improves the accuracy of target tracking, enhances the local character of the targe...This paper proposes a block Mean-Shift algorithm based on target real-time update and LBP texture features, through the target update improves the accuracy of target tracking, enhances the local character of the target through the target block, so as to improve the robustness of algorithm based on skin color backgrounds. And then analyze the Mean-Shift algorithm cannot recover quickly lost target tracking defects, and its improvement by combining the frame difference method.展开更多
文摘跟踪移动用户同时减少信令开销是通信系统位置管理研究中重要的方面。跟踪区列表是LTE系统中新引入的概念,它由多个跟踪区构成用来减少位置管理信令开销。受生活、工作、学习方面的影响,大部分用户具有固定的移动方式。提出了一种基于跟踪区关联性的跟踪区列表设计方法,它通过从用户历史移动路径中获取各跟踪区之间的关联性并建立各跟踪区的关联表,当跟踪区更新消息发生时,网络获取该消息中提供的上次访问跟踪区和用户当前所在跟踪区结合关联表进行跟踪区列表设计。该方法能够随不同上次访问跟踪区动态分配跟踪区列表,特别适用于大规模网络中。最后运用里斯本城镇网络数据,实验比较了基于跟踪区关联性的跟踪区列表设计方法和rule of thumb设计方法在一整天的信令开销。结果显示该方法在减少位置管理信令开销方面性能至少提升了11.5%。
文摘为了克服2G和3G移动通信网络位置管理方案的缺陷,4G长期演进(Long Term Evolution,LTE)采用了基于跟踪区列表(Tracking Area List,TAL)的位置管理方案。基于TAL的位置管理方案的性能取决于TAL分配方案。考虑到本地移动设备(User Equipment,UE)的活动区域相对固定,该文提出一种嵌入式马尔科夫链模型,用于分析本地UE的基于TAL的位置管理方案的信令开销。推导得到位置更新开销和寻呼开销的数学公式。利用这些公式,可搜索得到能使信令开销最低化的最佳TAL分配方案。
文摘Aim Aiming at the position tracking control for valve controlled motor electrohydraulic proportional servo systems mainly driving the static load torque, the tracking performance was studied in the presence of the variable gain and deadzone. Methods On the basis of conventional composite control with the deadzone compensation method, a comprehensive control approach with the deadzone and self adjusting feedforward compensation was proposed. Results Experimental results showed that the good tracking performance was achieved for the sinusoidal and constant velocity position tracking under a wide variations of load torque. Conclusion The position tracking accuracy for valve controlled motor electrohydraulic proportional servo systems has been solved by using the comprehensive control approach with the deadzone and self adjusting feedforward compensation.
文摘A novel Snake model with region information is proposed to detect and track moving objects. Generally, the region-information-based approach is sensitive to illumination changes and small movement in the background, while the edge-information-based approach often obtains incorrect results for ambiguous images. The two types of information are introduced in computing the image force. Edge-information-based features make the algorithm fast and robust, and region information makes the active confour energy function obtains correct results for ambiguous images. Furthermore, an automatic contour initialization method using double difference images is given to meet the requirement of video sequence tracking. Meanwhile, a simple forecast section is added to estimate the position of the contour in the algorithm so that it can improve the convergence speed of the active contour. Experimental results show that the computation time of the algorithm is less than 0.1 s/frame. And it can be applied to a real-time system.
文摘This paper proposes a block Mean-Shift algorithm based on target real-time update and LBP texture features, through the target update improves the accuracy of target tracking, enhances the local character of the target through the target block, so as to improve the robustness of algorithm based on skin color backgrounds. And then analyze the Mean-Shift algorithm cannot recover quickly lost target tracking defects, and its improvement by combining the frame difference method.
