AI大模型正引领下一个十年的信息与通信技术(information and communications technology,ICT)产业发展热点。智算中心网络是支撑AI大模型分布式训练的通信底座,是决定AI集群效能的关键要素之一。AI大模型的数据量和参数量不断扩张,给...AI大模型正引领下一个十年的信息与通信技术(information and communications technology,ICT)产业发展热点。智算中心网络是支撑AI大模型分布式训练的通信底座,是决定AI集群效能的关键要素之一。AI大模型的数据量和参数量不断扩张,给智算中心网络带来了严峻的挑战,同时给关键网络技术进行代际性创新带来了机遇。在AI大模型训练和推理过程中,提供数据的高性能和高安全传输是AI业务对智算中心网络的两大核心需求。高效的负载均衡、拥塞控制技术和网络安全协议是其中的关键网络技术。为应对大规模AI业务带来的严峻挑战,提出全调度以太网(global scheduled Ethernet,GSE)作为对应的解决方案,并搭建真实的测试环境对GSE和RoCE(remote direct memory access over converged Ethernet)网络进行性能对比测试。测试结果证明,GSE相较RoCE网络显著改善了任务完成时间(job completion time,JCT)。展开更多
In order to improve the performance of the security-reliability tradeoff （SRT）, a joint jammer and user scheduling （JJUS） scheme is proposed. First, a user with the maximal instantaneous channel capacity is select...In order to improve the performance of the security-reliability tradeoff （SRT）, a joint jammer and user scheduling （JJUS） scheme is proposed. First, a user with the maximal instantaneous channel capacity is selected to transmit its signal to the base station （ BS） in the transmission time slot. Then, when the user transmits its signal to BS, the jammer is invoked for transmitting artificial noise in order to perturb the eavesdropper’s reception. Simulation results show that increasing the number of users can enhance the SRT performance of the proposed JJUS scheme. In addition, the SRT performance of the proposed JJUS scheme is better than that of the traditional round-robin scheduling and pure user scheduling schemes. The proposed JJUS scheme can guarantee the secure transmission even in low main-to-eavesdropper ratio（ MER） regions.展开更多
In order to enhance the physical-layer security of wireless transmission in a wireless heterogeneous network (HetNet), a two-stage-based cooperative framework is advocated. To be specific, a source-destination (SD) pa...In order to enhance the physical-layer security of wireless transmission in a wireless heterogeneous network (HetNet), a two-stage-based cooperative framework is advocated. To be specific, a source-destination (SD) pair is opportunistically chosen at the beginning of the transmission slot, which can be used to assist the transmissions of other SD pairs. Under this framework, a transmit antenna selection assisted opportunistic SD pair scheduling (TAS-OSDS) scheme is proposed, and the intercept probability (IP) of the proposed TAS-OSDS, the conventional round-robin source-destination pair scheduling (RSDS) and the conventional non-cooperation (non-coop) schemes is also analyzed, where the RSDS and non-coop schemes are used for comparison with the proposed TAS-OSDS. Numerical results show that increasing the number of the SD pairs can effectively reduce the IP of the TAS-OSDS scheme, whereas the IP of the RSDS and the non-coop remain unchanged with an increasing number of the SD pairs. Furthermore, the TAS-OSDS scheme achieves a lower IP than that of the RSDS and the non-coop schemes, showing the superiority of the proposed TAS-OSDS.展开更多
Current MSM switching fabric has poor performance under unbalanced traffic. This paper presents an alternative, novel Central-stage Buffered Three-stage Clos switching (CB-3Clos) fabric and proves that this fabric can...Current MSM switching fabric has poor performance under unbalanced traffic. This paper presents an alternative, novel Central-stage Buffered Three-stage Clos switching (CB-3Clos) fabric and proves that this fabric can emulate output queuing switch without any speedup. By analyzing the condition to satisfy the central-stage load-balance, this paper also proposes a Central-stage Load-balanced-based Distributed Scheduling algorithm (CLDS) for CB-3Clos. The results show that, compared with Concurrent Round-Robin based Dispatching (CRRD) algorithm based on MSM, CLDS algorithm has high throughput irrespective with the traffic model and better performance in mean packet delay.展开更多
Complex terrain and working equipment in coal mine underground need a way to ensure coal mine safety. In this paper, the way to monitor the real-time status of underground equipment was put forward, and it was proved ...Complex terrain and working equipment in coal mine underground need a way to ensure coal mine safety. In this paper, the way to monitor the real-time status of underground equipment was put forward, and it was proved to be effective as commanding and dispatching system. Monitoring system for underground equipment based on panoramic images was effectively combined with real-time sensor data and static panoramic images of underground surrounding, which not only realizes real-time status monitoring for underground equipment, but also gets a direct scene for underground surrounding. B/S mode was applied in the monitoring system and this is convenient for users to monitor the equipment. Meantime, it can reduce the waste of the data resource.展开更多
Lithium (Li) metal is considered as the ultimate anode choice for developing next-generation high-energy batteries. However, the poor tolerance against moist air and the unstable solid electrolyte interphases (SEI) in...Lithium (Li) metal is considered as the ultimate anode choice for developing next-generation high-energy batteries. However, the poor tolerance against moist air and the unstable solid electrolyte interphases (SEI) induced by the intrinsic high reactivity of lithium bring series of obstacles such as the rigorous operating condition, the poor electrochemical performance, and safety anxiety of the cell, which to a large extent hinder the commercial utilization of Li metal anode. Here, an effective encapsulation strategy was reported via a facile drop-casting and a following heat-assisted cross-linking process. Benefiting from the inherent hydrophobicity and the compact micro-structure of the cross-linked poly(vinylidene-co-hex afluoropropylene) (PVDF–HFP), the as-encapsulated Li metal exhibited prominent stability toward moisture, as well corroborated by the evaluations both under the humid air at 25 °C with 30% relative humidity (RH) and pure water. Moreover, the encapsulated Li metal anode exhibits a decent electrochemical performance without substantially increasing the cell polarization due to the uniform and unblocked ion channels, which originally comes from the superior affinity of the PVDF–HFP polymer toward nonaqueous electrolyte. This work demonstrates a novel and valid encapsulation strategy for humiditysensitive alkali metal electrodes, aiming to pave the way for the large-scale and low-cost deployment of the alkali metal-based high-energy-density batteries.展开更多
A full-duplex optical passive access scheme is proposed and verified by simulation, in which hybrid 64/16/4-quadrature amplitude modulation(64/16/4QAM) orthogonal frequency division multiplexing(OFDM) optical signal i...A full-duplex optical passive access scheme is proposed and verified by simulation, in which hybrid 64/16/4-quadrature amplitude modulation(64/16/4QAM) orthogonal frequency division multiplexing(OFDM) optical signal is for downstream transmission and non-return-to-zero(NRZ) optical signal is for upstream transmission. In view of the transmitting and receiving process for downlink optical signal, in-phase/quadrature-phase(I/Q) modulation based on Mach-Zehnder modulator(MZM) and homodyne coherent detection technology are employed, respectively. The simulation results show that the bit error ratio(BER) less than hardware decision forward error correction(HD-FEC) threshold is successfully obtained over transmission path with 20-km-long standard single mode fiber(SSMF) for hybrid downlink modulation OFDM optical signal. In addition, by dividing the system bandwidth into several subchannels consisting of some continuous subcarriers, it is convenient for users to select different channels depending on requirements of communication.展开更多
Accurate prediction of wind power is significant for power system dispatching as well as safe and stable operation. By means of BP neural network, radial basis function neural network and support vector machine, a new...Accurate prediction of wind power is significant for power system dispatching as well as safe and stable operation. By means of BP neural network, radial basis function neural network and support vector machine, a new combined method of wind power prediction based on cooperative game theory is proposed. In the method, every single forecasting model is regarded as a member of the cooperative games, and the sum of square error of combination forecasting is taken as the result of cooperation. The result is divided among the members according to Shapley values, and then weights of combination forecasting can be obtained. Application results in an actual wind farm show that the proposed method can effectively improve prediction precision.展开更多
文摘AI大模型正引领下一个十年的信息与通信技术(information and communications technology,ICT)产业发展热点。智算中心网络是支撑AI大模型分布式训练的通信底座,是决定AI集群效能的关键要素之一。AI大模型的数据量和参数量不断扩张,给智算中心网络带来了严峻的挑战,同时给关键网络技术进行代际性创新带来了机遇。在AI大模型训练和推理过程中,提供数据的高性能和高安全传输是AI业务对智算中心网络的两大核心需求。高效的负载均衡、拥塞控制技术和网络安全协议是其中的关键网络技术。为应对大规模AI业务带来的严峻挑战,提出全调度以太网(global scheduled Ethernet,GSE)作为对应的解决方案,并搭建真实的测试环境对GSE和RoCE(remote direct memory access over converged Ethernet)网络进行性能对比测试。测试结果证明,GSE相较RoCE网络显著改善了任务完成时间(job completion time,JCT)。
基金The National Natural Science Foundation of China(No.61271207,61372104)the Science and Technology Project of SGCC(No.SGRIXTKJ[2015]349)
文摘In order to improve the performance of the security-reliability tradeoff （SRT）, a joint jammer and user scheduling （JJUS） scheme is proposed. First, a user with the maximal instantaneous channel capacity is selected to transmit its signal to the base station （ BS） in the transmission time slot. Then, when the user transmits its signal to BS, the jammer is invoked for transmitting artificial noise in order to perturb the eavesdropper’s reception. Simulation results show that increasing the number of users can enhance the SRT performance of the proposed JJUS scheme. In addition, the SRT performance of the proposed JJUS scheme is better than that of the traditional round-robin scheduling and pure user scheduling schemes. The proposed JJUS scheme can guarantee the secure transmission even in low main-to-eavesdropper ratio（ MER） regions.
基金The National Natural Science Foundation of China(No.91738201)the China Postdoctoral Science Foundation(No.2018M632347)+2 种基金the Natural Science Research of Higher Education Institutions of Jiangsu Province(No.18KJB510030)the Open Research Fund of National Mobile Communications Research Laboratory,Southeast University(No.2018D16)the Open Research Fund of Jiangsu Engineering Research Center of Communication and Netw ork Technology,NJUPT
文摘In order to enhance the physical-layer security of wireless transmission in a wireless heterogeneous network (HetNet), a two-stage-based cooperative framework is advocated. To be specific, a source-destination (SD) pair is opportunistically chosen at the beginning of the transmission slot, which can be used to assist the transmissions of other SD pairs. Under this framework, a transmit antenna selection assisted opportunistic SD pair scheduling (TAS-OSDS) scheme is proposed, and the intercept probability (IP) of the proposed TAS-OSDS, the conventional round-robin source-destination pair scheduling (RSDS) and the conventional non-cooperation (non-coop) schemes is also analyzed, where the RSDS and non-coop schemes are used for comparison with the proposed TAS-OSDS. Numerical results show that increasing the number of the SD pairs can effectively reduce the IP of the TAS-OSDS scheme, whereas the IP of the RSDS and the non-coop remain unchanged with an increasing number of the SD pairs. Furthermore, the TAS-OSDS scheme achieves a lower IP than that of the RSDS and the non-coop schemes, showing the superiority of the proposed TAS-OSDS.
基金Funded by the National Basic Research Program of China (No.2007CB307102)National High Tech Research and Development Program of China (No.2005AA121210)National Natural Science Foundation of China (No. 60572042)
文摘Current MSM switching fabric has poor performance under unbalanced traffic. This paper presents an alternative, novel Central-stage Buffered Three-stage Clos switching (CB-3Clos) fabric and proves that this fabric can emulate output queuing switch without any speedup. By analyzing the condition to satisfy the central-stage load-balance, this paper also proposes a Central-stage Load-balanced-based Distributed Scheduling algorithm (CLDS) for CB-3Clos. The results show that, compared with Concurrent Round-Robin based Dispatching (CRRD) algorithm based on MSM, CLDS algorithm has high throughput irrespective with the traffic model and better performance in mean packet delay.
基金Supported by the National Natural Science Foundation of China （51075029）
文摘Complex terrain and working equipment in coal mine underground need a way to ensure coal mine safety. In this paper, the way to monitor the real-time status of underground equipment was put forward, and it was proved to be effective as commanding and dispatching system. Monitoring system for underground equipment based on panoramic images was effectively combined with real-time sensor data and static panoramic images of underground surrounding, which not only realizes real-time status monitoring for underground equipment, but also gets a direct scene for underground surrounding. B/S mode was applied in the monitoring system and this is convenient for users to monitor the equipment. Meantime, it can reduce the waste of the data resource.
基金This work was supported by National Key Research and Development Program(2016YFA0202500)National Natural Science Foundation of China(21776019)Beijing Natural Science Foundation(L182021).
文摘Lithium (Li) metal is considered as the ultimate anode choice for developing next-generation high-energy batteries. However, the poor tolerance against moist air and the unstable solid electrolyte interphases (SEI) induced by the intrinsic high reactivity of lithium bring series of obstacles such as the rigorous operating condition, the poor electrochemical performance, and safety anxiety of the cell, which to a large extent hinder the commercial utilization of Li metal anode. Here, an effective encapsulation strategy was reported via a facile drop-casting and a following heat-assisted cross-linking process. Benefiting from the inherent hydrophobicity and the compact micro-structure of the cross-linked poly(vinylidene-co-hex afluoropropylene) (PVDF–HFP), the as-encapsulated Li metal exhibited prominent stability toward moisture, as well corroborated by the evaluations both under the humid air at 25 °C with 30% relative humidity (RH) and pure water. Moreover, the encapsulated Li metal anode exhibits a decent electrochemical performance without substantially increasing the cell polarization due to the uniform and unblocked ion channels, which originally comes from the superior affinity of the PVDF–HFP polymer toward nonaqueous electrolyte. This work demonstrates a novel and valid encapsulation strategy for humiditysensitive alkali metal electrodes, aiming to pave the way for the large-scale and low-cost deployment of the alkali metal-based high-energy-density batteries.
基金supported by the National Natural Science Foundation of China(No.61107064)the Chongqing University Innovation Team Founding(No.KJTD201320)the Chongqing Science and Technology Commission Foundation(No.cstc2016jcyjA 1233)
文摘A full-duplex optical passive access scheme is proposed and verified by simulation, in which hybrid 64/16/4-quadrature amplitude modulation(64/16/4QAM) orthogonal frequency division multiplexing(OFDM) optical signal is for downstream transmission and non-return-to-zero(NRZ) optical signal is for upstream transmission. In view of the transmitting and receiving process for downlink optical signal, in-phase/quadrature-phase(I/Q) modulation based on Mach-Zehnder modulator(MZM) and homodyne coherent detection technology are employed, respectively. The simulation results show that the bit error ratio(BER) less than hardware decision forward error correction(HD-FEC) threshold is successfully obtained over transmission path with 20-km-long standard single mode fiber(SSMF) for hybrid downlink modulation OFDM optical signal. In addition, by dividing the system bandwidth into several subchannels consisting of some continuous subcarriers, it is convenient for users to select different channels depending on requirements of communication.
文摘Accurate prediction of wind power is significant for power system dispatching as well as safe and stable operation. By means of BP neural network, radial basis function neural network and support vector machine, a new combined method of wind power prediction based on cooperative game theory is proposed. In the method, every single forecasting model is regarded as a member of the cooperative games, and the sum of square error of combination forecasting is taken as the result of cooperation. The result is divided among the members according to Shapley values, and then weights of combination forecasting can be obtained. Application results in an actual wind farm show that the proposed method can effectively improve prediction precision.
