 However, Isao Takahashi and Toshihiko Noguchi described a similar control technique termed DTC in an IEEJ paper presented in September 1984 and in an IEEE paper published in late 1986.The DTC innovation is thus usually credited to all three individuals.The only difference between DTC and DSC is the shape of the path along which the flux vector is controlled, the former path being quasi-circular whereas the latter is hexagonal such that the switching frequency of DTC is higher than DSC.