A systematic review of complex fuzzy sets and logic

Complex fuzzy sets and logic are an extension of type-1 fuzzy sets wherein memberships may be complex-valued. This has been an area of growing research focus in the fuzzy systems community for over a decade, with successful applications in time series forecasting and other areas. We conduct a systematic review of this topic to provide a framework to position new research in the field, consolidate the available theoretical results, catalogue the...