	\begin{align}
	\label{svdd0}
	\min_{c,\gamma \geq 0 \atop \xi_i \geq 0, i=1,\ldots,N} & \quad  \gamma + \rho \sum_{i=1}^N \xi_i \\
	\textrm{\rm subject to:} & \quad \| \mathbf{p}_i - c \|^2 - \gamma \leq \xi_i, \ \ i = 1, \ldots ,N. \nonumber
	\end{align}
