Retraction Note to: The change of groundwater quality in shallow layer based on parameter estimation and tennis physical fitness recovery

Abstract

This paper mainly studies the parameters of active panel data. According to the activity panel data to create a balance model, through the use of two improved GMM evaluation algorithm and according to the original GMM evaluation algorithm, the activity panel regression model creation, and dynamic activity panel parameter evaluation creation process. Based on the research and analysis of groundwater exploitation and other related literature, this paper believes that the reasonable development and utilization of groundwater resources in the island is a major problem to be solved in the development process of groundwater resources. Therefore, in the shallow groundwater area, it plays a very important role in the protection of groundwater resources. There is a very close relationship between surface water and groundwater, and surface water and groundwater can interact and influence each other, making the water quality change to a certain extent. Groundwater is the main source of water supply in China. According to the literature, athletes have good physical fitness, which can help athletes get better results in the competition. Through the research and analysis of high-level tennis players’ physical fitness, we can find more scientific and effective training methods, and make the high-level athletes’ physical energy supply more comprehensive and reasonable, so as to improve the sports level and competitive ability of athletes. In this paper, through the study of traditional GMM evaluation algorithm, the parameters of regression model and data model can be accurately estimated by activity panel.