



01348nas a2200121   4500008004100000245010600041210006900147260001400216520091000230100002501140700002401165856003701189       2019                        eng d00aA Probabilistic Framework and a Homotopy Method for Real-time Hierarchical Freight Dispatch Decisions0 aProbabilistic Framework and a Homotopy Method for Realtime Hiera  c2019/12/83 a<p><span style="color: rgb(51, 51, 51); font-family: &quot;Open Sans&quot;, &quot;Lucida Grande&quot;, &quot;Helvetica Neue&quot;, Helvetica, Arial, sans-serif; font-size: 14px;">We propose a real-time decision framework for multimodal freight dispatch through a system of hierarchical hubs, using a probabilistic model for transit times. Instead of assigning a fixed time to each transit, we advocate using historical records to identify characteristics of the probability density function for each transit time. We formulate a nonlinear optimization problem that defines dispatch decisions that minimize expected cost, using this probabilistic information. Finally, we propose an effective homotopy algorithm that (empirically) outperforms standard optimization algorithms on this problem by taking advantage of its structure, and we demonstrate its effectiveness on numerical examples.&nbsp;</span></p>1 aYousefzadeh, Roozbeh1 aO'Leary, Dianne, P.  uhttps://arxiv.org/abs/1912.03733