联邦学习是一种高效的分布式机器学习方法,其中多个设备使用自己的本地数据进行分布式模型训练,不需要交换本地数据,仅通过交换模型参数来构建共享的全局模型,从而保护用户的隐私。为了平衡模型性能和通信延迟,在半同步联邦学习场景下,...联邦学习是一种高效的分布式机器学习方法,其中多个设备使用自己的本地数据进行分布式模型训练,不需要交换本地数据,仅通过交换模型参数来构建共享的全局模型,从而保护用户的隐私。为了平衡模型性能和通信延迟,在半同步联邦学习场景下,使用权重参数建立了一个最小化模型性能和聚合时间的加权和的优化问题。优化变量包括进行全局模型更新的聚合时间、用户调度以及参与上传的用户的带宽和发射功率,通过使用交替方向乘子法(Alternating Direction Method of Multipliers, ADMM)将所提混合整数非线性规划(Mixed Integer Non-Linear Programming, MINLP)问题分解为两个子问题进行求解。仿真实验证明,所提算法能够以牺牲4%模型性能为代价,降低73%的聚合时间,显著提高了通信效率。展开更多
In order to determine the physiological mechanism of drought resistance of northern wheat in China,six drought resistant wheat and one sensitivity to drought wheat were planted in pots.They were subjected to drought t...In order to determine the physiological mechanism of drought resistance of northern wheat in China,six drought resistant wheat and one sensitivity to drought wheat were planted in pots.They were subjected to drought treatment and normal water when the plants grew to the 3-leaf stage.Samples were collected at 10,20,30,and 40 days after the drought treatment,respectively.The electrical conductivity,photosynthetic parameters,chlorophyll fluorescence parameters,sugar content,proline content,protein content,and active oxygen scavenging enzyme activity of the plants were detected,and the agronomic traits of the wheat varieties were investigated at maturity.The results indicated that the phenotype and yield-related factors of Darkhan 144 changed little under the drought stress.The relative electrical conductivity of Kefeng 6 and Darkhan 166 was lower under the drought stress,and their cell membrane was less damaged.The Darkhan 144 and Darkhan 166 had higher drought resistance coefficients,and were the wheat varieties with stronger drought resistance.However,the physiological mechanisms of drought resistance of these three wheat were different:Darkhan 144 maintained a higher photosynthetic activity under the drought stress;Darkhan 166 maintained a higher protein content,photosynthetic activity and active oxygen scavenging enzyme activity.In addition,other drought-resistant varieties Kefeng 6,Kefeng 10 and Longmai 26 had a higher content of osmoregulatory substances under the drought stress.展开更多
We develop a solar simulator composed of multiple xenon arc lamps combined with a faceted paraboloidal dish concentrator to drive a Stirling engine in our laboratory for all-weather indoor testing.Experiments and nume...We develop a solar simulator composed of multiple xenon arc lamps combined with a faceted paraboloidal dish concentrator to drive a Stirling engine in our laboratory for all-weather indoor testing.Experiments and numerical analysis are performed to determine the radiation flux and temperature distributions on the solar receiver surface.Based on the theoretical results,we present a receiver design for a solar Stirling engine with involute tubes closely conforming to the imaginary hemisphere to obtain a substantially uniform temperature field and a high solarthermal efficiency of 67.1%.展开更多
文摘联邦学习是一种高效的分布式机器学习方法,其中多个设备使用自己的本地数据进行分布式模型训练,不需要交换本地数据,仅通过交换模型参数来构建共享的全局模型,从而保护用户的隐私。为了平衡模型性能和通信延迟,在半同步联邦学习场景下,使用权重参数建立了一个最小化模型性能和聚合时间的加权和的优化问题。优化变量包括进行全局模型更新的聚合时间、用户调度以及参与上传的用户的带宽和发射功率,通过使用交替方向乘子法(Alternating Direction Method of Multipliers, ADMM)将所提混合整数非线性规划(Mixed Integer Non-Linear Programming, MINLP)问题分解为两个子问题进行求解。仿真实验证明,所提算法能够以牺牲4%模型性能为代价,降低73%的聚合时间,显著提高了通信效率。
基金the National Ministry of Science and Technology Key Project(2018YFE0123300)the National Modern Agricultural Wheat Industry Technology System Keshan Comprehensive Test Station(CARS‒03‒54)the Collaborative Innovation and Extension System of Modern Agricultural Wheat in Heilongjiang Province。
文摘In order to determine the physiological mechanism of drought resistance of northern wheat in China,six drought resistant wheat and one sensitivity to drought wheat were planted in pots.They were subjected to drought treatment and normal water when the plants grew to the 3-leaf stage.Samples were collected at 10,20,30,and 40 days after the drought treatment,respectively.The electrical conductivity,photosynthetic parameters,chlorophyll fluorescence parameters,sugar content,proline content,protein content,and active oxygen scavenging enzyme activity of the plants were detected,and the agronomic traits of the wheat varieties were investigated at maturity.The results indicated that the phenotype and yield-related factors of Darkhan 144 changed little under the drought stress.The relative electrical conductivity of Kefeng 6 and Darkhan 166 was lower under the drought stress,and their cell membrane was less damaged.The Darkhan 144 and Darkhan 166 had higher drought resistance coefficients,and were the wheat varieties with stronger drought resistance.However,the physiological mechanisms of drought resistance of these three wheat were different:Darkhan 144 maintained a higher photosynthetic activity under the drought stress;Darkhan 166 maintained a higher protein content,photosynthetic activity and active oxygen scavenging enzyme activity.In addition,other drought-resistant varieties Kefeng 6,Kefeng 10 and Longmai 26 had a higher content of osmoregulatory substances under the drought stress.
基金Supported by the National High Technology Research and Development Program of China under Grant No 2007AA05Z430.
文摘We develop a solar simulator composed of multiple xenon arc lamps combined with a faceted paraboloidal dish concentrator to drive a Stirling engine in our laboratory for all-weather indoor testing.Experiments and numerical analysis are performed to determine the radiation flux and temperature distributions on the solar receiver surface.Based on the theoretical results,we present a receiver design for a solar Stirling engine with involute tubes closely conforming to the imaginary hemisphere to obtain a substantially uniform temperature field and a high solarthermal efficiency of 67.1%.
