MOOC(Massive Open Online Courses)在为学习者提供优质课程的同时,低完成率成为影响其有效推广的重要因素。通过对edX开放数据集分析发现,学习者的逐渐流失是导致MOOC课程低完成率的因素之一,且学习行为与成绩之间存在复杂的相关性;基...MOOC(Massive Open Online Courses)在为学习者提供优质课程的同时,低完成率成为影响其有效推广的重要因素。通过对edX开放数据集分析发现,学习者的逐渐流失是导致MOOC课程低完成率的因素之一,且学习行为与成绩之间存在复杂的相关性;基于线性回归和深度神经网络(Deep Neural Network,DNN)预测学习者的成绩,实验证明,DNN能够更好地拟合学习行为与成绩之间复杂的相关性,实现对成绩更加精准的预测,预警学习者流失;对预测的潜在流失学习者迭代进行个性化的教学干预,提高MOOC课程的完成率。展开更多
Purpose For the High Energy Photon Source(HEPS),a green-field fourth-generation storage ring light source,the prelimi-nary design report(PDR)was completed in 2018,when the accelerator physics design had been basically...Purpose For the High Energy Photon Source(HEPS),a green-field fourth-generation storage ring light source,the prelimi-nary design report(PDR)was completed in 2018,when the accelerator physics design had been basically finished.During the subsequent hardware and engineering design of the HEPS storage ring based on the PDR design,a few problems and challenges emerged,calling for modifications of the lattice.Method In this paper,we will introduce the background and reasons for the modifications and present the linear optics and simulation results for the nonlinear performance of the modified lattice of the HEPS storage ring.Result and conclusion The modified lattice satisfies the requirements from hardware and engineering design.展开更多
基金supported by the High Energy Photon Source(HEPS),a major national science and technol-ogy infrastructurethe National Natural Science Foundation of China(No.11922512)+1 种基金Youth Inno-vation Promotion Association of Chinese Academy of Sciences(No.Y201904)Bureau of Frontier Sciences and Education of Chinese Academy of Sciences(No.QYZDJ-SSW-SLH001)
文摘Purpose For the High Energy Photon Source(HEPS),a green-field fourth-generation storage ring light source,the prelimi-nary design report(PDR)was completed in 2018,when the accelerator physics design had been basically finished.During the subsequent hardware and engineering design of the HEPS storage ring based on the PDR design,a few problems and challenges emerged,calling for modifications of the lattice.Method In this paper,we will introduce the background and reasons for the modifications and present the linear optics and simulation results for the nonlinear performance of the modified lattice of the HEPS storage ring.Result and conclusion The modified lattice satisfies the requirements from hardware and engineering design.
