Koji Fukagata Keio University The integral relationship on the skin friction drag (Fukagata et al., Phys. Fluids, 2002) and that on the power balance (Fukagata et al., Physica D, 2009) are introduced. As applications, a predetermined control relaminarizing a turbulent channel flow (Nakanishi et al., Int. J. Heat Fluid Flow, 2012) and a feedback control minimizing the dissipation of a flow around a circular cylinder (Naito and Fukagata, Phys. Rev. E, to appear) are introduced.