\begin{equation} \label{eq:US_cs_trans}
    \underline{\mathbf{F}} = \arg \; \min {}_{\underline{\mathbf{F}} \, \geq \, 0} \; \left|\left| \tilde{\underline{\mathbf{K}}} \, \underline{\mathbf{F}} - \tilde{\underline{\mathbf{S}}} \right| \right|_{2}^{2}
\end{equation}
