Free Field Representation of osp(2|1) and U_q(osp(2|1)) and N=1 (q-)Superstring Correlation Functions

The free field realization of irreducible representations of $\os$ is constructed, by a unified and systematic scheme. The $q$-analog of this unified scheme is used to construct $q$-free field realization of irreducible representations of $\uos$. By using these realization, the two point function of $N=1$ superconformal (q-superconformal) model based on $\os$ ($\uos$) symmetry have been calculated.