SSRN Author: Samir ElhedhliSamir Elhedhli SSRN Content
http://www.ssrn.com/author=391295
http://www.ssrn.com/rss/en-usThu, 30 Jun 2016 03:14:31 GMTeditor@ssrn.com (Editor)Thu, 30 Jun 2016 03:14:31 GMTwebmaster@ssrn.com (WebMaster)SSRN RSS Generator 1.0REVISION: Optimal Shipment Decisions for an Airfreight Forwarder: Formulation and Solution MethodsWe study the freight forwarder’s shipment planning problem in an airfreight forwarding network where a set of cargo shipments have to be transported to given destinations. We provide mixed integer programming formulations that use piecewise-linear cargo rates and account for volume and weight constraints, flight departure/arrival times, as well as shipment-ready times.
After exploring the solution of such models using CPLEX, we devise two solution methodologies to handle large problem sizes. The first is based on Lagrangian relaxation, where the problems decompose into a set of knapsack problems and a set of network flow problems. The second is a local branching heuristic that combines branching ideas and local search. The two approaches show promising results in providing good quality heuristic solutions within reasonable computational times, for difficult and large shipment consolidation problems.
http://www.ssrn.com/abstract=2771329
http://www.ssrn.com/1508482.htmlWed, 29 Jun 2016 07:02:15 GMTREVISION: Optimal Shipment Decisions for an Airfreight Forwarder: Formulation and Solution MethodsWe study the freight forwarder’s shipment planning problem in an airfreight forwarding network where a set of cargo shipments have to be transported to given destinations. We provide mixed integer programming formulations that use piecewise-linear cargo rates and account for volume and weight constraints, flight departure/arrival times, as well as shipment-ready times.
After exploring the solution of such models using CPLEX, we devise two solution methodologies to handle large problem sizes. The first is based on Lagrangian relaxation, where the problems decompose into a set of knapsack problems and a set of network flow problems. The second is a local branching heuristic that combines branching ideas and local search. The two approaches show promising results in providing good quality heuristic solutions within reasonable computational times, for difficult and large shipment consolidation problems.
http://www.ssrn.com/abstract=2771329
http://www.ssrn.com/1506775.htmlWed, 22 Jun 2016 08:49:22 GMTREVISION: Optimal Shipment Decisions for an Airfreight Forwarder: Formulation and Solution MethodsWe study the freight forwarder’s shipment planning problem in an airfreight forwarding network where a set of cargo shipments have to be transported to given destinations. We provide mixed integer programming formulations that use piecewise-linear cargo rates and account for volume and weight constraints, flight departure/arrival times, as well as shipment-ready times.
After exploring the solution of such models using CPLEX, we devise two solution methodologies to handle large problem sizes. The first is based on Lagrangian relaxation, where the problems decompose into a set of knapsack problems and a set of network flow problems. The second is a local branching heuristic that combines branching ideas and local search. The two approaches show promising results in providing good quality heuristic solutions within reasonable computational times, for difficult and large shipment consolidation problems.
http://www.ssrn.com/abstract=2771329
http://www.ssrn.com/1504204.htmlMon, 13 Jun 2016 05:30:32 GMTNew: Airfreight Forwarding Under System-Wide and Double DiscountsWe consider the shipment consolidation and freight forwarding problem under two discount schemes: the system-wide and the double-discount. In the system-wide scheme, the cost associated with one flight does not only depend on the quantity of freight assigned to that flight, but also on the total freight assigned to other flights operated by the same carrier. In the double-discount scheme, there are cost savings based on the quantity shipped on a given flight on top of the system-wide discount. We propose models based on multi-commodity network flow formulations that take into account practical aspects such as cargo unsplitability, shipment volume and over-declaration. We propose solution methodologies based on Lagrangian relaxation and local branching. Numerical testing reveals the efficiency of the approaches presented and sheds light on some managerial implications. We find that freight forwarders do not only reduce costs from the system-wide and the double-discount schemes, but ...
http://www.ssrn.com/abstract=2724060
http://www.ssrn.com/1465290.htmlFri, 29 Jan 2016 17:40:03 GMTREVISION: Classification Models Via Tabu Search: An Application to Early Stage Venture ClassificationWe model the decision making process used by experts at the Canadian Innovation Centre to classify early stage venture proposals based on potential commercial success. The decision is based on thirty seven attributes that take values in (-1; 0; 1). We adopt a conjunctive decision framework due to Astebro and Elhedhli that selects a subset of attributes and determines two threshold values: one for the maximum allowed negatives (n) and one for minimum required positives (p). A proposal is classified as a success if the number of positives is greater than or equal to p and the number of negatives is less than or equal to n over the selected attributes. Based on data of 561 observations, the selection of attributes and the determination of the threshold values is modeled as a large-scale mixed integer program. Two solution approaches are explored: Benders decomposition and Tabu search. The first was very slow to converge, while the second provided high quality solutions quickly. Tabu ...
http://www.ssrn.com/abstract=2636835
http://www.ssrn.com/1425843.htmlSat, 05 Sep 2015 06:05:57 GMTREVISION: Classification Models Via Tabu Search: An Application to Early Stage Venture ClassificationWe model the decision making process used by experts at the Canadian Innovation Centre to classify early stage venture proposals based on potential commercial success. The decision is based on thirty seven attributes that take values in (-1; 0; 1). We adopt a conjunctive decision framework due to Astebro and Elhedhli that selects a subset of attributes and determines two threshold values: one for the maximum allowed negatives (n) and one for minimum required positives (p). A proposal is classified as a success if the number of positives is greater than or equal to p and the number of negatives is less than or equal to n over the selected attributes. Based on data of 561 observations, the selection of attributes and the determination of the threshold values is modeled as a large-scale mixed integer program. Two solution approaches are explored: Benders decomposition and Tabu search. The first was very slow to converge, while the second provided high quality solutions quickly. Tabu ...
http://www.ssrn.com/abstract=2636835
http://www.ssrn.com/1415655.htmlWed, 29 Jul 2015 02:45:49 GMT