  A unified canonical operator formalism for quantum stochastic differential
equations, including the quantum stochastic Liouville equation and the quantum
Langevin equation both of the It\^o and the Stratonovich types, is presented
within the framework of Non-Equilibrium Thermo Field Dynamics (NETFD). It is
performed by introducing an appropriate martingale operator in the
Schr\"odinger and the Heisenberg representations with fermionic and bosonic
Brownian motions. In order to decide the double tilde conjugation rule and the
thermal state conditions for fermions, a generalization of the system
consisting of a vector field and Faddeev-Popov ghosts to dissipative open
situations is carried out within NETFD.
