Date(s) - September 15, 2023
10:30 am - 11:30 am

Weil Hall 406

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Halit Uster profile picture

Halit Uster
Date : Friday, September 15, 2023
Mode : In-Person
Affiliation: Southern Methodist University
Bio: Visit Page


Title : Capacitated Relay Network Design with Link Imbalance Constraints in Truckload Transportation

Abstract : High driver turnover and driver shortage are chronic and costly problems in truckload trucking industry. Drivers’ extended on-the-road times with low-quality of llife, irregular schedules, and low get-home rates are commonly attributed as the main culprits in both academic and industry literature. Among its other benefits, use of a relay network can help to alleviate the turnover, and in turn, the shortage problems. In this study, we consider the strategic design of a relay network that can provide an effective underlying structure to facilitate the intended efficient truckload operations acceptable to all stakeholders (drivers, company, and customers). In doing so, we explicitly consider design characteristics that are important in the operational setting including driver tour lengths, load imbalance on the relay connections, and the route circuity levels. To solve our resulting mixed integer programming model, we develop a Lagrangean Decomposition based algorithm that produces tight lower bounds and incorporates an effective heuristic to generate near-optimal solutions. Our numerical tests illustrate that large size problems can be solved with small optimality gaps within reasonable runtimes. Moreover, based on our computational experiments, we present analyses on the influence of input data parameters on algorithmic performance and the network characteristics, trade-offs between imbalance requirements and cost components, and the effects of link capacity on design.

Bio : Halit √úster is a Professor in the OREM Department at SMU. His research interests are in the areas of logistics, design of networked systems, and applied optimization. His publications appeared in Transportation Science, IIE Transactions, Naval Research Logistics, INFORMS Journal on Computing, and IEEE/ACM Transactions on Networking, among others. His research has been funded by National Science Foundation, US Department of Agriculture, and industry. He was a recipient of the Caterpillar Teaching Excellence Award in Look College of Engineering of TAMU in 2011 and INFORMS Moving Spirit Award. He serves as an Associate Editor for IISE Transactions and Transportation Science, and as an editorial board member for Sustainability Analytics and Modelling. √úster is a member of INFORMS and IISE and serves these communities in varying capacities.