ZTE Corporation (ZTE) demonstrated the industry’s first operational end-to-end IMS system with convergent BSS/OSS at the Management World 2008, an annual global event targeted for the Management of Information, Commu...ZTE Corporation (ZTE) demonstrated the industry’s first operational end-to-end IMS system with convergent BSS/OSS at the Management World 2008, an annual global event targeted for the Management of Information, Communications, and Entertainment Services sector organized by TeleManagement Forum in Nice, France from May 20-22, 2008.ZTE’s end-to-end IMS system comprises IMS clienterminal,展开更多
The current study aims to improve the performance of the electrohydraulic servo system(EHSS)by increasing the volumetric efficiency of the pump and reducing electrical power consumption to a minimum value.An experimen...The current study aims to improve the performance of the electrohydraulic servo system(EHSS)by increasing the volumetric efficiency of the pump and reducing electrical power consumption to a minimum value.An experimental setup has been designed and built to control the cylinder position using a programmable logic controller to provide the appropriate motor speed from the AC drive to control the velocity of the hydraulic actuator;the induction motor is driven by an AC drive using a tune proportional-integral-variable frequency drive(TPI-VFD)space vector modulation(SVM)hybrid technology.Theoretically,it was analyzed and simulated by MATLAB,which showed that the starting current was reduced by 81%compared to the traditional system.Also,the settling time of the system decreased to 0.35 s to reach a steady state with a minimum error of 0.03 and an overshoot of 0.3%.On the other hand,the experimental results of the EHSS show that the three-phase induction motor with a closed-loop speed control AC drive with a programmable logic controller PLC based system is the best case for determining the appropriate operating speed.The optimum speed,frequency,and voltage were 1325.3 rpm,46.6 Hz,and 354.16 V.In addition,enhancement is achieved in closed-loop VFD-PLC,where at 6.5 bar pressure and 3.4 LPM flow,the volumetric efficiency after the pump improves to 98.6%while it reaches 96.3%before the cylinder at a flow rate of 3.32 LPM.Finally,in the closed-loop VFD-PLC in the expansion stroke,the rated electrical power consumption of the three-phase IM decreased to 532 W at the speed of 1325.3 rpm,resulting in energy savings of 20.6%.展开更多
针对电力语音通信系统架构老化、协议异构、运维割裂等问题,提出基于IP多媒体子系统(IP Multimedia Subsystem,IMS)的语音接入网融合改造方案,构建统一信令控制、媒体处理与服务质量(Quality of Service,QoS)保障体系。设计端到端架构,...针对电力语音通信系统架构老化、协议异构、运维割裂等问题,提出基于IP多媒体子系统(IP Multimedia Subsystem,IMS)的语音接入网融合改造方案,构建统一信令控制、媒体处理与服务质量(Quality of Service,QoS)保障体系。设计端到端架构,完成多协议信令映射、安全与QoS协同机制,实现控制面集中化与接口能力开放。通过构建实验环境开展高并发性能测试,验证系统在会话控制、媒体传输与资源调度方面的提升效果,结果表明改造方案具备工程可行性与部署价值。展开更多
摘要ZTE Corporation (ZTE) demonstrated the industry’s first operational end-to-end IMS system with convergent BSS/OSS at the Management World 2008, an annual global event targeted for the Management of Information, Communications, and Entertainment Services sector organized by TeleManagement Forum in Nice, France from May 20-22, 2008.ZTE’s end-to-end IMS system comprises IMS clienterminal,
摘要The current study aims to improve the performance of the electrohydraulic servo system(EHSS)by increasing the volumetric efficiency of the pump and reducing electrical power consumption to a minimum value.An experimental setup has been designed and built to control the cylinder position using a programmable logic controller to provide the appropriate motor speed from the AC drive to control the velocity of the hydraulic actuator;the induction motor is driven by an AC drive using a tune proportional-integral-variable frequency drive(TPI-VFD)space vector modulation(SVM)hybrid technology.Theoretically,it was analyzed and simulated by MATLAB,which showed that the starting current was reduced by 81%compared to the traditional system.Also,the settling time of the system decreased to 0.35 s to reach a steady state with a minimum error of 0.03 and an overshoot of 0.3%.On the other hand,the experimental results of the EHSS show that the three-phase induction motor with a closed-loop speed control AC drive with a programmable logic controller PLC based system is the best case for determining the appropriate operating speed.The optimum speed,frequency,and voltage were 1325.3 rpm,46.6 Hz,and 354.16 V.In addition,enhancement is achieved in closed-loop VFD-PLC,where at 6.5 bar pressure and 3.4 LPM flow,the volumetric efficiency after the pump improves to 98.6%while it reaches 96.3%before the cylinder at a flow rate of 3.32 LPM.Finally,in the closed-loop VFD-PLC in the expansion stroke,the rated electrical power consumption of the three-phase IM decreased to 532 W at the speed of 1325.3 rpm,resulting in energy savings of 20.6%.
摘要针对电力语音通信系统架构老化、协议异构、运维割裂等问题,提出基于IP多媒体子系统(IP Multimedia Subsystem,IMS)的语音接入网融合改造方案,构建统一信令控制、媒体处理与服务质量(Quality of Service,QoS)保障体系。设计端到端架构,完成多协议信令映射、安全与QoS协同机制,实现控制面集中化与接口能力开放。通过构建实验环境开展高并发性能测试,验证系统在会话控制、媒体传输与资源调度方面的提升效果,结果表明改造方案具备工程可行性与部署价值。