Summary
International Symposium on Nonlinear Theory and Its Applications
2022
Session Number:A3L-E
Session:
Number:A3L-E-03
Nonlinear Trends Extraction for COVID-19 Daily New Cases in Japan
Fumihiko Ishiyama,
pp.103-106
Publication Date:12/12/2022
Online ISSN:2188-5079
Summary:
We have developed a nonlinear method of time series analysis, that allows us to obtain multiple nonlinear trends from a given set of numerical data. We propose to apply the method to recognize the ongoing status of COVID-19 infection, and applied to the time series of daily new cases in Japan. We found that there is only a single nonlinear trend, and this result justifies the use of a week-based infection growth rate as an index. In addition, the fitting with the obtained nonlinear trend holds for a duration of more than three months for the Delta variant infection time series. The fitting also visualizes the transition to the Omicron variant.