
(a) The optimal travel cost of the SODNDPRC1 


(b) The optimal travel cost of the SODNDPAARC1 


(c) The relative improvement of the optimal objective value of the SODNDPRC1 against SODNDPAARC1 

Figure 2: The optimal objective value of the SODNDPRC1 and SODNDPAARC1 models, and the relative improvement of the optimal objective value of the SODNDPRC1 against SODNDPAARC1 under different available budgets and uncertainty levels. 
