Table 2. Objective function in STAD and STAD-R.

The correlation ρ is computed between the original distance matrix D_X and the distance matrix derived from the shortest path graph in D_U. The ratio R is calculated from the network at each iteration considering the edges included in the network. Note that distance d_{network edge} are normalized values between zero and one.

STAD	STAD-R
max ρ(DX, DU)	$max\rho (D_X,D_U)R=max\rho \sum 1-d_{\mathrm{n}\mathrm{e}\mathrm{t}\mathrm{w}\mathrm{o}\mathrm{r}\mathrm{k}\mathrm{e}\mathrm{d}\mathrm{g}\mathrm{e}\mathrm{s}}\sum 1+d_{\mathrm{n}\mathrm{e}\mathrm{t}\mathrm{w}\mathrm{o}\mathrm{r}\mathrm{k}\mathrm{e}\mathrm{d}\mathrm{g}\mathrm{e}\mathrm{s}}$