Original sentence: He has extensively researched the formation of the Okinawa Trough, and claimed to have predicted the volcanic eruptions in Miyake Island (1983), Izu Ōshima (1986), and Mount Unzen (1991).Kimura believes that those structures have been modified by humans between 10,000 and 6,000 years ago.Some of his theories, such as the location of the ancient Yamatai Kingdom, the theory for earthquake prediction and the interpretation of the Yonaguni Monument, are controversial
Edited sentence: He has extensively researched the formation of the Okinawa Trough, and insisted that he had predicted the volcanic eruptions in Miyake Island (1983), Izu Ōshima (1986), and Mount Unzen (1991).Kimura believes that those structures have been modified by humans between 10,000 and 6,000 years ago , although the interpretation is not accepted in the academic society.Most of his studies, concerning the location of the ancient Yamatai Kingdom, the theory for earthquake prediction and the interpretation of the Yonaguni Monument, are not seen as plausible