Oxford University Press, Data Science, Science, Mathematics, Algorithms.
includes Kitchin cycles of 40–59 months, Juglar cycles of 7–11 years, and Kuznets swings of 15–25 years. Kondratieff, himself, believed that Kondratieff waves co-existed with both intermediate (7–11 years) and shorter (about 3 1/2 years) cycles. This flexibility is useful for data mining historical