We demonstrate a multi-fidelity(MF)machine learning ensemble framework for the inverse design of photonic surfaces,trained on a dataset of 11,759 samples that we fabricate using high throughput femtosecond laser proce...We demonstrate a multi-fidelity(MF)machine learning ensemble framework for the inverse design of photonic surfaces,trained on a dataset of 11,759 samples that we fabricate using high throughput femtosecond laser processing.The MF ensemble combines an initial low fidelity model for generating design solutions,with a high fidelity model that refines these solutions through local optimization.The combined MF ensemble can generate multiple disparate sets of laser-processing parameters that can each produce the same target input spectral emissivity with high accuracy(root mean squared errors<2%).SHapley Additive exPlanations analysis shows transparent model interpretability of the complex relationship between laser parameters and spectral emissivity.Finally,the MF ensemble is experimentally validated by fabricating and evaluating photonic surface designs that it generates for improved efficiency energy harvesting devices.Our approach provides a powerful tool for advancing the inverse design of photonic surfaces in energy harvesting applications.展开更多
A high‐fidelity multibody‐system dynamic model of the looped tether transportation system(L‐TTS)is proposed in this study to study its large deformation as well as large overall motion.The absolute nodal coordinate...A high‐fidelity multibody‐system dynamic model of the looped tether transportation system(L‐TTS)is proposed in this study to study its large deformation as well as large overall motion.The absolute nodal coordinate formulation(ANCF)‐based gradient‐deficient beam element is employed to establish the accurate model of the two flexible tethers subject to large deformations.The relative movement of climbers along tethers is described by using the sliding joint model based on ANCF.To reduce the collision risks between tethers and climbers,two libration suppression strategies,namely,the decelerated motion of climbers relative to tethers and multiple climbers per tether are investigated in this study.Several numerical simulations not only validate the effectiveness of the two strategies in reducing the collision risks between climbers and tethers,the overall librations of L‐TTS,and the magnitudes of the longitudinal elastic force of tethers,but also verify the good performance of the high‐fidelity model proposed in this study for dynamic simulation of the L‐TTS in microgravity conditions.展开更多
基金supported by the Laboratory Directed Research and Development Program of Lawrence Berkeley National Laboratory under U.S.Department of Energy Contract No.DE-AC02-05CH11231supported by ARPA-E Contract No.2107-1539J.Mueller was supported by the U.S.Department of Energy,Office of Science,Office of Advanced Scientific Computing Research,Scientific Discovery through Advanced Computing(SciDAC)program through the FASTMath Institute under Contract No.DE-AC36-08GO28308 at the National Renewable Energy Laboratory.
文摘We demonstrate a multi-fidelity(MF)machine learning ensemble framework for the inverse design of photonic surfaces,trained on a dataset of 11,759 samples that we fabricate using high throughput femtosecond laser processing.The MF ensemble combines an initial low fidelity model for generating design solutions,with a high fidelity model that refines these solutions through local optimization.The combined MF ensemble can generate multiple disparate sets of laser-processing parameters that can each produce the same target input spectral emissivity with high accuracy(root mean squared errors<2%).SHapley Additive exPlanations analysis shows transparent model interpretability of the complex relationship between laser parameters and spectral emissivity.Finally,the MF ensemble is experimentally validated by fabricating and evaluating photonic surface designs that it generates for improved efficiency energy harvesting devices.Our approach provides a powerful tool for advancing the inverse design of photonic surfaces in energy harvesting applications.
基金This study was supported in part by the National Natural Science Foundation of China(Grant No.11902159)the Natural Science Foundation of Jiangsu Province of China(Grant No.BK20190390)It was also supported in part by the China Postdoctoral Science Foundation(Grant No.2019M661849).
文摘A high‐fidelity multibody‐system dynamic model of the looped tether transportation system(L‐TTS)is proposed in this study to study its large deformation as well as large overall motion.The absolute nodal coordinate formulation(ANCF)‐based gradient‐deficient beam element is employed to establish the accurate model of the two flexible tethers subject to large deformations.The relative movement of climbers along tethers is described by using the sliding joint model based on ANCF.To reduce the collision risks between tethers and climbers,two libration suppression strategies,namely,the decelerated motion of climbers relative to tethers and multiple climbers per tether are investigated in this study.Several numerical simulations not only validate the effectiveness of the two strategies in reducing the collision risks between climbers and tethers,the overall librations of L‐TTS,and the magnitudes of the longitudinal elastic force of tethers,but also verify the good performance of the high‐fidelity model proposed in this study for dynamic simulation of the L‐TTS in microgravity conditions.
