Week 1 prediction using Seq2Seq model.

As of 2022, COVID-19, first reported in Wuhan, China, in November 2019, has become a worldwide epidemic, causing numerous infections and casualties and enormous social and economic damage. To mitigate its impact, various COVID-19 prediction studies have emerged, most of them using mathematical models and artificial intelligence for prediction. However, the problem with these models is that their prediction accuracy is considerably reduced when the duration of the COVID-19 outbreak is short. In this paper, we propose a new prediction method combining Word2Vec and the existing long short-term memory and Seq2Seq + Attention model. We compare the prediction error of the existing and proposed models with the COVID-19 prediction results reported from five US states: California, Texas, Florida, New York, and Illinois. The results of the experiment show that the proposed model combining Word2Vec and the existing long short-term memory and Seq2Seq + Attention achieves better prediction results and lower errors than the existing long short-term memory and Seq2Seq + Attention models. In experiments, the Pearson correlation coefficient increased by 0.05 to 0.21 and the RMSE decreased by 0.03 to 0.08 compared to the existing method.</div

Isotropic Sodiation Behaviors of Ultrafast-Chargeable Tin Crystals

High-rate performance and mechanical stability of anode materials are the two important characteristics that are necessary to develop fast-charging batteries with longevity. In the present study, we demonstrate that both high rate performance and mechanical stability of the anode can be achieved with the Na–Sn battery system. Experiments show that the sodiation rate in crystalline Sn (c-Sn) is 2–3 orders of magnitude faster than that reported for the Li–Si system. Furthermore, this extraordinary rate is nearly the same regardless of the orientation of c-Sn, which can improve the cycle life by retarding the pulverization of c-Sn. Two main microstructural features responsible for the observed characteristics are identified: (1) a transformation from crystalline to amorphous phase occurring at thin layers of c-Sn near the interfacial front and (2) pipe diffusion of Na through sodiation-induced dislocations. In this study, the observed behaviors are explained by elucidating the diffusion kinetics, whereas the associated mechanistic origins are analyzed by resolving the diffusion process of Na+ near the Na/Sn interface using atomic simulations

Anisotropic Swelling Governed by Orientation-Dependent Interfacial Na Diffusion in Single-Crystalline Sb

The anisotropic volume expansion of anode materials produces locally inhomogeneous residual stresses, which frequently induce fracture of the anode materials and reduce battery capacity and cycle life. Much of our understanding of the anisotropic swelling behavior of anode materials is based on electron microscopy and macroscopic structural analysis techniques, which are insufficient to elucidate the atomistic origin of the anisotropic swelling behavior. In this study, we perform in situ sodiation experiments with single-crystalline Sb anodes followed by atomic simulations to determine the diffusion kinetics governing the sodiation of Sb and its associated swelling behavior. In situ sodiation experiments demonstrate that the rate of diffusion of Na into single-crystalline Sb anodes differs by more than a factor of 2 depending on the orientation of the Sb crystal, causing the crystal to swell anisotropically. This observed anisotropic diffusion is explained here by determining the orientation-dependent diffusion kinetics, while the associated structural origins are clarified by studying the interfacial Na diffusion in the atomically thin layer preceding the advancing interface

Isotropic Sodiation Behaviors of Ultrafast-Chargeable Tin Crystals

High-rate performance and mechanical stability of anode materials are the two important characteristics that are necessary to develop fast-charging batteries with longevity. In the present study, we demonstrate that both high rate performance and mechanical stability of the anode can be achieved with the Na–Sn battery system. Experiments show that the sodiation rate in crystalline Sn (c-Sn) is 2–3 orders of magnitude faster than that reported for the Li–Si system. Furthermore, this extraordinary rate is nearly the same regardless of the orientation of c-Sn, which can improve the cycle life by retarding the pulverization of c-Sn. Two main microstructural features responsible for the observed characteristics are identified: (1) a transformation from crystalline to amorphous phase occurring at thin layers of c-Sn near the interfacial front and (2) pipe diffusion of Na through sodiation-induced dislocations. In this study, the observed behaviors are explained by elucidating the diffusion kinetics, whereas the associated mechanistic origins are analyzed by resolving the diffusion process of Na+ near the Na/Sn interface using atomic simulations

Week 3 prediction using Seq2Seq model.

As of 2022, COVID-19, first reported in Wuhan, China, in November 2019, has become a worldwide epidemic, causing numerous infections and casualties and enormous social and economic damage. To mitigate its impact, various COVID-19 prediction studies have emerged, most of them using mathematical models and artificial intelligence for prediction. However, the problem with these models is that their prediction accuracy is considerably reduced when the duration of the COVID-19 outbreak is short. In this paper, we propose a new prediction method combining Word2Vec and the existing long short-term memory and Seq2Seq + Attention model. We compare the prediction error of the existing and proposed models with the COVID-19 prediction results reported from five US states: California, Texas, Florida, New York, and Illinois. The results of the experiment show that the proposed model combining Word2Vec and the existing long short-term memory and Seq2Seq + Attention achieves better prediction results and lower errors than the existing long short-term memory and Seq2Seq + Attention models. In experiments, the Pearson correlation coefficient increased by 0.05 to 0.21 and the RMSE decreased by 0.03 to 0.08 compared to the existing method.</div

Hyperparameter of model.

As of 2022, COVID-19, first reported in Wuhan, China, in November 2019, has become a worldwide epidemic, causing numerous infections and casualties and enormous social and economic damage. To mitigate its impact, various COVID-19 prediction studies have emerged, most of them using mathematical models and artificial intelligence for prediction. However, the problem with these models is that their prediction accuracy is considerably reduced when the duration of the COVID-19 outbreak is short. In this paper, we propose a new prediction method combining Word2Vec and the existing long short-term memory and Seq2Seq + Attention model. We compare the prediction error of the existing and proposed models with the COVID-19 prediction results reported from five US states: California, Texas, Florida, New York, and Illinois. The results of the experiment show that the proposed model combining Word2Vec and the existing long short-term memory and Seq2Seq + Attention achieves better prediction results and lower errors than the existing long short-term memory and Seq2Seq + Attention models. In experiments, the Pearson correlation coefficient increased by 0.05 to 0.21 and the RMSE decreased by 0.03 to 0.08 compared to the existing method.</div

Anisotropic Swelling Governed by Orientation-Dependent Interfacial Na Diffusion in Single-Crystalline Sb

The anisotropic volume expansion of anode materials produces locally inhomogeneous residual stresses, which frequently induce fracture of the anode materials and reduce battery capacity and cycle life. Much of our understanding of the anisotropic swelling behavior of anode materials is based on electron microscopy and macroscopic structural analysis techniques, which are insufficient to elucidate the atomistic origin of the anisotropic swelling behavior. In this study, we perform in situ sodiation experiments with single-crystalline Sb anodes followed by atomic simulations to determine the diffusion kinetics governing the sodiation of Sb and its associated swelling behavior. In situ sodiation experiments demonstrate that the rate of diffusion of Na into single-crystalline Sb anodes differs by more than a factor of 2 depending on the orientation of the Sb crystal, causing the crystal to swell anisotropically. This observed anisotropic diffusion is explained here by determining the orientation-dependent diffusion kinetics, while the associated structural origins are clarified by studying the interfacial Na diffusion in the atomically thin layer preceding the advancing interface

Anisotropic Swelling Governed by Orientation-Dependent Interfacial Na Diffusion in Single-Crystalline Sb

The anisotropic volume expansion of anode materials produces locally inhomogeneous residual stresses, which frequently induce fracture of the anode materials and reduce battery capacity and cycle life. Much of our understanding of the anisotropic swelling behavior of anode materials is based on electron microscopy and macroscopic structural analysis techniques, which are insufficient to elucidate the atomistic origin of the anisotropic swelling behavior. In this study, we perform in situ sodiation experiments with single-crystalline Sb anodes followed by atomic simulations to determine the diffusion kinetics governing the sodiation of Sb and its associated swelling behavior. In situ sodiation experiments demonstrate that the rate of diffusion of Na into single-crystalline Sb anodes differs by more than a factor of 2 depending on the orientation of the Sb crystal, causing the crystal to swell anisotropically. This observed anisotropic diffusion is explained here by determining the orientation-dependent diffusion kinetics, while the associated structural origins are clarified by studying the interfacial Na diffusion in the atomically thin layer preceding the advancing interface

Isotropic Sodiation Behaviors of Ultrafast-Chargeable Tin Crystals

High-rate performance and mechanical stability of anode materials are the two important characteristics that are necessary to develop fast-charging batteries with longevity. In the present study, we demonstrate that both high rate performance and mechanical stability of the anode can be achieved with the Na–Sn battery system. Experiments show that the sodiation rate in crystalline Sn (c-Sn) is 2–3 orders of magnitude faster than that reported for the Li–Si system. Furthermore, this extraordinary rate is nearly the same regardless of the orientation of c-Sn, which can improve the cycle life by retarding the pulverization of c-Sn. Two main microstructural features responsible for the observed characteristics are identified: (1) a transformation from crystalline to amorphous phase occurring at thin layers of c-Sn near the interfacial front and (2) pipe diffusion of Na through sodiation-induced dislocations. In this study, the observed behaviors are explained by elucidating the diffusion kinetics, whereas the associated mechanistic origins are analyzed by resolving the diffusion process of Na+ near the Na/Sn interface using atomic simulations