Abstract: An active edge caching method based on community discovery and weighted federated learning for selecting an optimal caching user and developing an optimal caching strategy; user grouping method based on community discovery is first provided, users are divided into different user groups according to users' mobility and social attributes, degrees of importance of different users are computed in each user group, and most important user is selected as a caching node to provide content distribution services; a content popularity prediction framework based on attention weighted federated learning is provided for combining attention weighted federated learning mechanism with deep learning algorithm to predict future user preferences for different content, so as to improve content popularity prediction accuracy and solve user privacy disclosure; finally, hot content is cached on selected caching users according to prediction results, to achieve goals of reducing network transmission latency and network operation cost

Abstract: A composition kit for preparing a polyurethane foam and a preparation method and applications thereof are provided. The composition kit for preparing a polyurethane foam includes a first component and a second component. The first component and the second component are disposed in different containers respectively. The first component includes an organic isocyanate and a low boiling point foaming agent. The second component includes a polyol composition, a high boiling point foaming agent, a composite catalyst, water, and a silicone oil.

Abstract: A composition kit for preparing a polyurethane foam and a preparation method and applications thereof are provided. The composition kit for preparing a polyurethane foam includes a first component and a second component. The first component and the second component are disposed in different containers respectively. The first component includes an organic isocyanate and a low boiling point foaming agent. The second component includes a polyol composition, a high boiling point foaming agent, a composite catalyst, water, and a silicone oil.