利用BBR(Bottleneck bandwidth and RTT)算法虽可以实现在复杂网络中带宽的充分利用,但该算法对网络噪音所造成的丢包现象敏感,且该算法因存在协议内部不公平的问题而无法实现物联数据的实时高效获取。针对以上问题,提出了1种基于深度...利用BBR(Bottleneck bandwidth and RTT)算法虽可以实现在复杂网络中带宽的充分利用,但该算法对网络噪音所造成的丢包现象敏感,且该算法因存在协议内部不公平的问题而无法实现物联数据的实时高效获取。针对以上问题,提出了1种基于深度强化学习的起搏增益优化算法(Deep reinforcement learning of BBR,BBR-DRL)。首先,通过获取数据传输的往返时延、发送窗口大小和网络带宽等环境参数来实时感知网络状态;然后,结合环境参数,利用起搏增益进行动态调整,使得BBR算法能够及时与外部动态网络环境进行交互,从而降低丢包敏感度、提高不同往返时延(Round-trip time,RTT)流之间的公平性。实验结果表明,与经典BBR算法相比,所提出的BBR-DRL算法协议内部的公平性提高到了98.2%,丢包敏感性明显降低。展开更多
The well number and the cavity length of 1.55μm wavelength In 1-x-y Ga y Al x As MQW DFB lasers are optimized using a simple model.A low threshold,maximum operating temperature of 550～560K,and high relaxat...The well number and the cavity length of 1.55μm wavelength In 1-x-y Ga y Al x As MQW DFB lasers are optimized using a simple model.A low threshold,maximum operating temperature of 550～560K,and high relaxation oscillation frequency of over 30GHz MQW DFB laser is presented.展开更多
we demonstrate the adjustability of optimal input power(OIP) of the radio over fiber(RoF) link by proper link gain control in the central unit(CU) and remote antenna unit(RAU).The experiment results show that the read...we demonstrate the adjustability of optimal input power(OIP) of the radio over fiber(RoF) link by proper link gain control in the central unit(CU) and remote antenna unit(RAU).The experiment results show that the reading and writing distance(RWD)of the radio frequency identification(RFID)service and the throughput of the WiFi service have a max increase of 3cm and 6.975Mbit/s respectively when the OIP value equals to output power of commercial products,compared with OIP value with 5-dBm right/left shift to the output power.展开更多
The relationship between engine mechanics and thermo-dynamics has been investigated by means of numerical simulation.The inherent mismatching between the mechanical behaviors and the thermodynamic process in internal ...The relationship between engine mechanics and thermo-dynamics has been investigated by means of numerical simulation.The inherent mismatching between the mechanical behaviors and the thermodynamic process in internal combustion engine is identified,which is believed to be one of the important limiting factors of energy efficiency for conventional engines available in the current market.An approach for engine efficiency improvement through optimal matching between mechanics and thermodynamics(OMBMT)is proposed.An ideal matching model is defined and the conflicts due to the constraints among the mapping strokes in a 4-stroke engine are analyzed.A novel mechanical model is built for approaching optimal matching among all 4 individual strokes in a 4-stroke spark-ignition engine,which is composed of non-circular gears(NCG)and integrated with conventional slider crank engine mechanism.By means of digital mechanical model and numerical simulation,the matching gains among all 4 strokes are defined and calculated for quantifying the NCG engine efficiency improvement by comparing with a baseline engine.The potentials with the OMBMT implemented and the enhancements made by NCG mechanism for engines in terms of overall engine efficiency are reported.Based on the results achieved,it is recommended that the feasibility studies and the experimental validations should be conducted to verify the engine matching concept and effectiveness of the NCG mechanism engine model proposed,and the engine performance and NCG design parameters should be further optimized.展开更多
文摘利用BBR(Bottleneck bandwidth and RTT)算法虽可以实现在复杂网络中带宽的充分利用,但该算法对网络噪音所造成的丢包现象敏感,且该算法因存在协议内部不公平的问题而无法实现物联数据的实时高效获取。针对以上问题,提出了1种基于深度强化学习的起搏增益优化算法(Deep reinforcement learning of BBR,BBR-DRL)。首先,通过获取数据传输的往返时延、发送窗口大小和网络带宽等环境参数来实时感知网络状态;然后,结合环境参数,利用起搏增益进行动态调整,使得BBR算法能够及时与外部动态网络环境进行交互,从而降低丢包敏感度、提高不同往返时延(Round-trip time,RTT)流之间的公平性。实验结果表明,与经典BBR算法相比,所提出的BBR-DRL算法协议内部的公平性提高到了98.2%,丢包敏感性明显降低。
基金Supported by the National Natural Science Foundation of China(61922058,62103277,62025305)the Fellowship of China National Postdoctoral Program for Innovative Talents(BX2021181)。
文摘The well number and the cavity length of 1.55μm wavelength In 1-x-y Ga y Al x As MQW DFB lasers are optimized using a simple model.A low threshold,maximum operating temperature of 550～560K,and high relaxation oscillation frequency of over 30GHz MQW DFB laser is presented.
基金supported in part by the National Basic Research Program of China （2012CB315704） the National Natural Science Foundation of China（No.61275068） the Key Grant Project of Chinese Ministry of Education（No.313049）
文摘we demonstrate the adjustability of optimal input power(OIP) of the radio over fiber(RoF) link by proper link gain control in the central unit(CU) and remote antenna unit(RAU).The experiment results show that the reading and writing distance(RWD)of the radio frequency identification(RFID)service and the throughput of the WiFi service have a max increase of 3cm and 6.975Mbit/s respectively when the OIP value equals to output power of commercial products,compared with OIP value with 5-dBm right/left shift to the output power.
文摘The relationship between engine mechanics and thermo-dynamics has been investigated by means of numerical simulation.The inherent mismatching between the mechanical behaviors and the thermodynamic process in internal combustion engine is identified,which is believed to be one of the important limiting factors of energy efficiency for conventional engines available in the current market.An approach for engine efficiency improvement through optimal matching between mechanics and thermodynamics(OMBMT)is proposed.An ideal matching model is defined and the conflicts due to the constraints among the mapping strokes in a 4-stroke engine are analyzed.A novel mechanical model is built for approaching optimal matching among all 4 individual strokes in a 4-stroke spark-ignition engine,which is composed of non-circular gears(NCG)and integrated with conventional slider crank engine mechanism.By means of digital mechanical model and numerical simulation,the matching gains among all 4 strokes are defined and calculated for quantifying the NCG engine efficiency improvement by comparing with a baseline engine.The potentials with the OMBMT implemented and the enhancements made by NCG mechanism for engines in terms of overall engine efficiency are reported.Based on the results achieved,it is recommended that the feasibility studies and the experimental validations should be conducted to verify the engine matching concept and effectiveness of the NCG mechanism engine model proposed,and the engine performance and NCG design parameters should be further optimized.
