Classification of Different Branes at Angles

In this paper, we consider two D-branes rotated with respect to each other, and argue that in this way one can find brane configurations preserving ${1 \f 16}$ of SUSY. Also we classify different brane configurations preserving ${1 \f 2}$, ${1 \f 4}$, ${3 \f 16}$,${1 \f 8}$, ${1 \f 16}$ of SUSY.