Stefan Røpke's Homepage

Welcome to my homepage!

I'm a associate professor at DTU Transport .

I received my Ph.D. degree in January 2006 at the Computer science department at the University of Copenhagen (DIKU).

Last update: September 4, 2009

Research Interests

Exact and heuristic methods for solving combinatorial optimization problems.
Vehicle routing problems.
Branch-and-cut
Column generation

Publications

In international journals
J.-F. Cordeau, G. Laporte, F. Pasin, S. Ropke	Scheduling Technicians and Tasks in a Telecommunications Company	Journal of Scheduling, 2009, Forthcoming	PDF file
I. Dumitrescu, S. Ropke, J.-F. Cordeau, G. Laporte	The Traveling Salesman Problem with Pickup and Delivery: Polyhedral Results and a Branch-and-Cut Algorithm	Mathematical Programming, Series A and B, vol. 121, issue 2 (2009), 269-305.	PDF file
S. Ropke, J.-F. Cordeau	Branch-and-Cut-and-Price for the Pickup and Delivery Problem with Time Windows	Transportation Science, 2008, Forthcoming.	PDF file (revised version)
M.A. Krajewska, H. Kopfer, G. Laporte, S. Ropke, G. Zaccour	Horizontal cooperation among freight carriers: request allocation and profit sharing	Journal of the Operational Research Society, Vol. 59, Issue 11 (2008), 1483-1491	PDF file (revised), JORS version
D. Pisinger, S. Ropke	A general heuristic for vehicle routing problems	Computers & Operations Research, Vol. 34, Issue 8 (2007), 2403-2435.	PDF file (technical report), ScienceDirect
S. Ropke, J.-F. Cordeau, G. Laporte	Models and a Branch-and-Cut Algorithm for Pickup and Delivery Problems with Time Windows	Networks, Vol. 49, Issue 4, 2007, 258-272.	PDF file (revised) Networks version
S. Ropke, D. Pisinger	An Adaptive Large Neighborhood Search Heuristic for the Pickup and Delivery Problem with Time Windows	Transportation Science, 40 (2006), 455-472.	PDF file (technical report - updated)
S. Ropke, D. Pisinger	A Unified Heuristic for Vehicle Routing Problems with Backhauls	European Journal of Operational Research, 171 (2006), 750-775.	PDF file (technical report), ScienceDirect
Book chapters
D. Pisinger, S. Ropke	Large neighborhood search	Handbook of Metaheuristics, 2nd edition, M. Gendreau and J.-Y. Potvin(eds), 2009, Forthcoming	PDF file
J.-F. Cordeau, G. Laporte, S. Ropke	Recent Models and Algorithms for One-to-One Pickup and Delivery Problems	Vehicle Routing: Latest Advances and Challenges, B. L., Golden, S. Raghavan and E. A. Wasil (eds), Kluwer, Boston (2008), 327--357	PDF file (revised)
Submitted
H.L. Petersen, A. Larsen, O.B.G. Madsen, B. Petersen, S. Ropke	The Simultaneous Vehicle Scheduling and Passenger Service Problem	Technical report, 2009	PDF file
K. Buhrkal, S. Zuglian, S. Ropke, J. Larsen, R. Lusby	Models for the Discrete Berth Allocation Problem: A Computational Comparison	Technical report, 2009	PDF file
T. Bektas, G. Erdogan, S. Ropke	Formulations and Branch-and-Cut Algorithms for the Generalized Vehicle Routing Problem	Technical report, 2009	PDF file
L. Moccia, J.-F. Cordeau, G. Laporte, S. Ropke, M.P. Valentini	Modeling and Solving a Multimodal Routing Problem with Timetables and Time Windows	Technical report, 2008	PDF file
Ph.D thesis
S. Ropke	Heuristic and exact algorithms for vehicle routing problems	Ph.D. Thesis, Computer science department at the University of Copenhagen (DIKU), December 2005.	PDF file

Data sets

Instances at my page

The vehicle routing problem with backhauls and time windows (VRPBTW). Instances - readme.txt - VRPBTW Solution checker (source code) - note.
The mixed vehicle routing problem with backhauls (MVRPB). Instances - readme.txt
The multiple depot mixed vehicle routing problem with backhauls (MDMVRPB). Instances - readme.txt
The pickup and delivery problem with time windows (PDPTW), instances from the paper An Adaptive Large Neighborhood Search Heuristic for the Pickup and Delivery Problem with Time Windows. Instances
The pickup and delivery problem with time windows (PDPTW), instances from the paper Branch-and-Cut-and-Price for the Pickup and Delivery Problem with Time Windows. Instances
The traveling salesman problem with pickup and delivery (TSPPD), instances from the paper The Traveling Salesman Problem with Pickup and Delivery: Polyhedral Results and a Branch-and-Cut Algorithm. Instances
The capacitated vehicle routing problem (CVRP). The excel file below list the solutions obtained for three well-known CVRP datasets by a number of heuristics proposed in the the scientific literature. The best known solution for each instance is also listed. Please inform me if you obtain a better solution for one of these instances so I can keep the tables up-to-date (published papers are prefered). Please note that the excel file contains four "sheets". You can switch between the sheets using the tabs at the bottom of your Excel window. Last update March 2009.
- Heuristic solutions for the CVRP

Problems elsewhere

Teaching

I have been giving lectures in the following graduate courses:

Other

Research Links - Photos from "academic events"

Contact Information

The easiest way to get in touch with me is to send me an email: sr@transport.dtu.dk

You can also call me at the office using this number : +45 45 25 15 17

Or you can send ordinary mail to this address:
Stefan Ropke
Bygningstorvet 115
2800 Kgs. Lyngby
Denmark

If you want to drop by my office then it is office no. 018.