To deal with over-shooting and gouging in high speed machining, a novel approach for velocity smooth link is proposed. Considering discrete tool path, cubic spline curve fitting is used to find dangerous points, and a...To deal with over-shooting and gouging in high speed machining, a novel approach for velocity smooth link is proposed. Considering discrete tool path, cubic spline curve fitting is used to find dangerous points, and according to spatial geometric properties of tool path and the kinematics theory, maximum optimal velocities at dangerous points are obtained. Based on method of velocity control characteristics stored in control system, a fast algorithm for velocity smooth link is analyzed and formulated. On-line implementation results show that the proposed approach makes velocity changing more smoothly compared with traditional velocity control methods and improves productivity greatly.展开更多
This paper investigates the cross-correlation characteristics of large-scale parameters(LSPs) and small-scale fading(SSF) for high-speed railway(HSR) multilink propagation scenarios, based on realistic measurements co...This paper investigates the cross-correlation characteristics of large-scale parameters(LSPs) and small-scale fading(SSF) for high-speed railway(HSR) multilink propagation scenarios, based on realistic measurements conducted on Beijing to Tianjin HSR line in China. A long-term evolution-based channel sounding system is utilized in the measurements to obtain the channel data. By applying a proposed time-delay based dynamic partition method, multi-link channel impulse responses are extracted from the raw channel data. Then, the statistical results of LSPs, including shadow fading, K-factor, and root-mean-square delay spread are derived and the cross-correlation coefficients of these LPSs are calculated. Moreover, the SSF spatial correlation and cross-correlation of SSF are analyzed. These results can be used to exploit multi-link channel model and to optimize the next-generation HSR communication system.展开更多
在对TigerSHARC芯片上自带的Link口通信协议进行研究的基础上,提出其在FPGA上实现的方法,并编写了代码在ALTERA公司的STRATIX II FPGA EP2S60F672I4进行了工程实现,测试结果表明:在FPGA上实现的Link口传输速度可达500MB/s,且能够与Tiger...在对TigerSHARC芯片上自带的Link口通信协议进行研究的基础上,提出其在FPGA上实现的方法,并编写了代码在ALTERA公司的STRATIX II FPGA EP2S60F672I4进行了工程实现,测试结果表明:在FPGA上实现的Link口传输速度可达500MB/s,且能够与Tiger-SHARC自带的Link口完全兼容,该Link口在FPGA上的实现为TigerSHARC与FPGA之间的互联提供了一种新的框架结构,具有一定的实用和推广价值。展开更多
With the increase of high-speed network backbones, the performance of server’s network interface gradually becomes a pivotal factor. This study provides a method called Ethernet Links Trunking (ELT) technology for ac...With the increase of high-speed network backbones, the performance of server’s network interface gradually becomes a pivotal factor. This study provides a method called Ethernet Links Trunking (ELT) technology for achieving efficient connec-tivity between backbones and servers, which provides higher bandwidth and availability of server network interface. The overview of the ELT technology and the results of performance experiment are presented in this paper. Findings showed that the network bandwidth can be scaled by multiple ELT technologies so that more reliable network connectivity can be guaranteed. Some crucial techniques such as Adapter Load Balancing (ALB) and Adapter Fault Tolerance (AFT) are presented in this paper. Experimental results showed that parallel channels of Fast Ethernet are both necessary and sufficient for supporting the data rates of multiple concurrent file transfers on file server.展开更多
基金This project is supported by National Hi-tech Research and Development Program of China (863 Program, No. 2002AA421150)Specialized Re-search Fund for Doctor Program of Higher Education of China (No. 20030335091).
文摘To deal with over-shooting and gouging in high speed machining, a novel approach for velocity smooth link is proposed. Considering discrete tool path, cubic spline curve fitting is used to find dangerous points, and according to spatial geometric properties of tool path and the kinematics theory, maximum optimal velocities at dangerous points are obtained. Based on method of velocity control characteristics stored in control system, a fast algorithm for velocity smooth link is analyzed and formulated. On-line implementation results show that the proposed approach makes velocity changing more smoothly compared with traditional velocity control methods and improves productivity greatly.
基金supported by the Beijing Municipal Natural Science Foundation under Grant 4174102the National Natural Science Foundation of China under Grant 61701017+1 种基金the Open Research Fund through the National Mobile Communications Research Laboratory, Southeast University, under Grant 2018D11the Fundamental Research Funds for the Central Universities under Grant 2018JBM003
文摘This paper investigates the cross-correlation characteristics of large-scale parameters(LSPs) and small-scale fading(SSF) for high-speed railway(HSR) multilink propagation scenarios, based on realistic measurements conducted on Beijing to Tianjin HSR line in China. A long-term evolution-based channel sounding system is utilized in the measurements to obtain the channel data. By applying a proposed time-delay based dynamic partition method, multi-link channel impulse responses are extracted from the raw channel data. Then, the statistical results of LSPs, including shadow fading, K-factor, and root-mean-square delay spread are derived and the cross-correlation coefficients of these LPSs are calculated. Moreover, the SSF spatial correlation and cross-correlation of SSF are analyzed. These results can be used to exploit multi-link channel model and to optimize the next-generation HSR communication system.
文摘在对TigerSHARC芯片上自带的Link口通信协议进行研究的基础上,提出其在FPGA上实现的方法,并编写了代码在ALTERA公司的STRATIX II FPGA EP2S60F672I4进行了工程实现,测试结果表明:在FPGA上实现的Link口传输速度可达500MB/s,且能够与Tiger-SHARC自带的Link口完全兼容,该Link口在FPGA上的实现为TigerSHARC与FPGA之间的互联提供了一种新的框架结构,具有一定的实用和推广价值。
基金Project (No. 2001AA111011) supported by the the Hi-Tech Re-search and Development Program (863) of China
文摘With the increase of high-speed network backbones, the performance of server’s network interface gradually becomes a pivotal factor. This study provides a method called Ethernet Links Trunking (ELT) technology for achieving efficient connec-tivity between backbones and servers, which provides higher bandwidth and availability of server network interface. The overview of the ELT technology and the results of performance experiment are presented in this paper. Findings showed that the network bandwidth can be scaled by multiple ELT technologies so that more reliable network connectivity can be guaranteed. Some crucial techniques such as Adapter Load Balancing (ALB) and Adapter Fault Tolerance (AFT) are presented in this paper. Experimental results showed that parallel channels of Fast Ethernet are both necessary and sufficient for supporting the data rates of multiple concurrent file transfers on file server.
