Prem Kumar

Journal publications [4]

2015

Piu F., Kumar P., Bierlaire M., Speranza G. (2015). Introducing a preliminary Consists Selection in the Locomotive Assignment Problem. Transportation Research Part E: Logistics and Transportation Review 82 :217-237


@Article{PiuKumaBierSper15,
  author = {Francesco Piu and Prem Kumar and Michel Bierlaire and Grazia Speranza},
  title = {Introducing a preliminary Consists Selection in the Locomotive Assignment Problem},
  journal = {Transportation Research Part E: Logistics and Transportation Review},
  year = {2015},
  volume = {82},
  pages = {217-237},
  DOI = {10.1016/j.tre.2015.07.003},
  note = {Accepted on Jul 06, 2015}}}

Kumar P., Bierlaire M. (2015). Optimizing Fueling Decisions for Locomotives in Railroad Networks. Transportation Science 49 (1):149-159


@Article{KumaBier13,
  author = {Prem Kumar and Michel Bierlaire},
  title = {Optimizing Fueling Decisions for Locomotives in Railroad Networks},
  journal = {Transportation Science},
  year = {2015},
  volume = {49},
  number = {1},
  pages = {149-159},
  DOI = {10.1287/trsc.2013.0479},
  note = {Accepted on Apr 01, 2013}}}

2014

Kumar P., Bierlaire M. (2014). Multi-Objective Airport Gate Assignment Problem in Planning and Operations. Journal of Advanced Transportation 48 (7):902-926


@Article{ViswBier13,
  author = {Prem Kumar and Michel Bierlaire},
  title = {Multi-Objective Airport Gate Assignment Problem in Planning and Operations},
  journal = {Journal of Advanced Transportation},
  year = {2014},
  volume = {48},
  number = {7},
  pages = {902-926},
  DOI = {10.1002/atr.1235},
  note = {Accepted on May 01, 2013}}}

2010

Kumar P., Kumar P. (2010). A DSS to Optimize Facings on the Shelf of a Retail Store. International Journal of Business Insights and Transformation 3 (1)


@Article{KumaKuma10,
  author = {Prem Kumar and Pradeep Kumar},
  title = {A DSS to Optimize Facings on the Shelf of a Retail Store},
  journal = {International Journal of Business Insights and Transformation},
  year = {2010},
  volume = {3},
  number = {1}}}

Technical reports [2]

2012

Kumar P., Bierlaire M. (2012). Multi-Objective Airport Gate Assignment Problem in Planning and Operations. Report TRANSP-OR 120321


@TechReport{KumarBier12,
  author = {Prem Kumar and Michel Bierlaire},
  title = {Multi-Objective Airport Gate Assignment Problem in Planning and Operations},
  institution = {Transport and Mobility Laboratory, Ecole Polytechnique F\'ed\'erale de Lausanne},
  year = {2012},
  type = {Technical Report},
  number = {TRANSP-OR 120321},
  address = {Lausanne, Switzerland}}}

2011

Kumar P., Bierlaire M. (2011). Optimizing Fueling Decisions for Locomotives in Railroad Networks. Report TRANSP-OR 111006


@TechReport{KumarBier11,
  author = {Prem Kumar and Michel Bierlaire},
  title = {Optimizing Fueling Decisions for Locomotives in Railroad Networks},
  institution = {Transport and Mobility Laboratory, Ecole Polytechnique F\'ed\'erale de Lausanne},
  year = {2011},
  type = {Technical Report},
  number = {TRANSP-OR 111006},
  address = {Lausanne, Switzerland}}}

Articles in conference proceedings [6]

2012

Kumar P., Bierlaire M. (2012) Optimizing Locations for a Vehicle Sharing System. Proceedings of the Swiss Transport Research Conference (STRC), 02.05.2012-04.05.2012, Ascona, Switzerland


@InProceedings{Kumar_STRC_2012,
  author = {Prem Kumar and Michel Bierlaire},
  title = {Optimizing Locations for a Vehicle Sharing System},
  booktime = {Proceedings of the Swiss Transport Research Conference (STRC), 02.05.2012-04.05.2012},
  year = {2012},
  address = {Ascona, Switzerland}}}

2011

Kumar P., Bierlaire M. (2011) Generalized Airport Gate Assignment. Proceedings of the International Federations of Operations Research (IFORS), 10-15 July 2011, Melbourne, Australia


@InProceedings{IFORS_2011_Kumar,
  author = {Prem Kumar and Michel Bierlaire},
  title = {Generalized Airport Gate Assignment},
  booktime = {Proceedings of the International Federations of Operations Research (IFORS), 10-15 July 2011},
  year = {2011},
  address = {Melbourne, Australia}}}

Kumar P., Bierlaire M. (2011) Experience of Optimizing Fueling Decisions for Locomotives in Railroad Networks. Proceedings of the INTERNATIONAL CONFERENCE OF OPERATIONS RESEARCH (OR2011), 30 AUG - 2 SEP 2011, ZURICH, SWITZERLAND


@InProceedings{Kumar_OR2011,
  author = {Prem Kumar and Michel Bierlaire},
  title = {Experience of Optimizing Fueling Decisions for Locomotives in Railroad Networks},
  booktime = {Proceedings of the INTERNATIONAL CONFERENCE OF OPERATIONS RESEARCH (OR2011), 30 AUG - 2 SEP 2011},
  year = {2011},
  address = {ZURICH, SWITZERLAND}}}

Kumar P., Bierlaire M. (2011) Multi-Objective Airport Gate Assignment Problem. Proceedings of the Swiss Transport Research Conference (STRC), 11-13 May 2011, Monte Verita, CH


@InProceedings{KUMAR_STRC_2011,
  author = {Prem Kumar and Michel Bierlaire},
  title = {Multi-Objective Airport Gate Assignment Problem},
  booktime = {Proceedings of the Swiss Transport Research Conference (STRC), 11-13 May 2011},
  year = {2011},
  address = {Monte Verita, CH}}}

2010

Kumar P., Bierlaire M. (2010) Optimal Staffing Plans at Airports. Proceedings of the INFORMS Annual Meeting 2010 (INFORMS2010), 7-10, Nov 2010, Austin, USA


@InProceedings{OptAirportINFORMS2010,
  author = {Prem Kumar and Michel Bierlaire},
  title = {Optimal Staffing Plans at Airports},
  booktime = {Proceedings of the INFORMS Annual Meeting 2010 (INFORMS2010), 7-10, Nov 2010},
  year = {2010},
  address = {Austin, USA}}}

Kumar P., Bierlaire M., Gallay O. (2010) Generalized Algorithms for Crew Planning: Survey and Future Directions for Railways. Proceedings of the 10th Swiss Transport Research Conference (STRC), September 1-3, 2010, Ascona, Switzerland


@InProceedings{KumarBierGall2010,
  author = {Prem Kumar and Michel Bierlaire and Olivier Gallay},
  title = {Generalized Algorithms for Crew Planning: Survey and Future Directions for Railways},
  booktime = {Proceedings of the 10th Swiss Transport Research Conference (STRC), September 1-3, 2010},
  year = {2010},
  address = {Ascona, Switzerland}}}

Talks [5]

2012

Kumar P., Bierlaire M. Location Optimization for a Vehicle Sharing Service May 04, 2012. Swiss Transport Research Conference, STRC, Ascona.


@Misc{Kumar_STRC_12,
  author = {Prem Kumar and Michel Bierlaire},
  title = {Location Optimization for a Vehicle Sharing Service},
  howpublished = {\url{https://transp-or.epfl.ch/documents/talks/Kumar_STRC_12.pdf}},
  year = {2012},
  note = {Presented at Swiss Transport Research Conference, STRC, Ascona}}}

2010

Kumar P. A Mathematical Model for the Locomotive Refueling Problem September 27, 2010. Internal Seminar Series, TRANSP-OR, EPFL.


@Misc{KUMAR_LOCO_REFUEL10,
  author = {Prem Kumar},
  title = {A Mathematical Model for the Locomotive Refueling Problem},
  howpublished = {\url{https://transp-or.epfl.ch/documents/talks/KUMAR_LOCO_REFUEL10.pdf}},
  year = {2010},
  note = {Presented at Internal Seminar Series, TRANSP-OR, EPFL}}}

Kumar P. Gate Optimization: Schedule Planning and Day of Operations September 09, 2010. VIII IBM Joint OR Days, University of Fribourg, Fribourg.


@Misc{KUMAR_ORDAYS10,
  author = {Prem Kumar},
  title = {Gate Optimization: Schedule Planning and Day of Operations},
  howpublished = {\url{https://transp-or.epfl.ch/documents/talks/KUMAR_ORDAYS10.pdf}},
  year = {2010},
  note = {Presented at VIII IBM Joint OR Days, University of Fribourg, Fribourg}}}

Kumar P. Crew Scheduling in Transportation: A Survey and Proposed Directions September 03, 2010. Swiss Transport Research Conference, Universita Della Svizerra Italiano, Monte Verita, Ascona.


@Misc{Kumar_STRC10,
  author = {Prem Kumar},
  title = {Crew Scheduling in Transportation: A Survey and Proposed Directions},
  howpublished = {\url{https://transp-or.epfl.ch/documents/talks/Kumar_STRC10.pdf}},
  year = {2010},
  note = {Presented at Swiss Transport Research Conference, Universita Della Svizerra Italiano, Monte Verita, Ascona}}}

Kumar P. An Introduction to EPFL and TRANSP-OR June 24, 2010. AGIFORS Schedule Planning 2010, EPFL, Starling Hotel.


@Misc{Prem_AGIF2010,
  author = {Prem Kumar},
  title = {An Introduction to EPFL and TRANSP-OR},
  howpublished = {\url{https://transp-or.epfl.ch/documents/talks/Prem_AGIF2010.pdf}},
  year = {2010},
  note = {Presented at AGIFORS Schedule Planning 2010, EPFL, Starling Hotel}}}

Research projects [3]

2010

Optimizing Staffing Plans at Airports

Minimizing operating costs for maintaining ground personnel at airports is a complex problem due to uneven flight activities, passenger service expectations and staffing inflexibilities due to shift durations. In this work, we would use the flight schedule and service criteria to develop a method to find optimal shift timings that considers non-productive time due to activity changeovers, the mix of full-time and part-time workers and passenger waiting time criteria.
- Oct 01, 2010 - Oct 01, 2011
- Sponsor: Transport and Mobility Laboratory, EPFL
- Principal investigator: Michel Bierlaire
- Project manager: Prem Kumar
Robust Optimization of Railway Locomotive Assignment

Locomotive assignment at Railway companies is a complex problem that must optimally assign a set of locomotives to known, scheduled trains. Each train has a power and traction requirement and locomotives may be available in groups known as "consist". There is a cost involved in breaking or adding a locomotive to a consist. Determining an optimal locomotive assignment that would also be robust to handle delays, maintenance requirements and other unknown factors is a complex problem. We are inspired from the research in a similar, closely related subject in the airline industry and would explore the possibilities of extending the same to railways. This project would be a part of the larger concept of "Flexible Transportation Systems"
- Oct 01, 2010 - Sep 30, 2011
- Sponsor: Transport and Mobility Laboratory, EPFL
- Principal investigator: Michel Bierlaire
- Project manager: Prem Kumar
- Collaborator: Francesco Piu
A Solution Technique for the Locomotive Refueling Problem

This problem corresponds to refueling locomotives at different station yards during the course of its journey. Locomotive tanks have a fixed fuel capacity and prices of fuel vary across yards. In addition, there is a fixed cost for hiring a refueling truck at a yard and every refueling stop that the locomotive makes. Locomotives can power different train sets during a cyclical planning horizon running 14 days. The objective of this exercise is to minimize the total fuel costs � fixed and operational � for a given set of locomotives, trains and yards. In addition, there are numerous constraints relating to refueling, locomotive tank capacity, refueling truck capacity etc. This problem has similarity to the network flow problem. We formulate this problem as a Mixed Integer Program (MIP) and present our experience in this project.
- Jul 15, 2010 - Jul 15, 2012
- Sponsor: Transport and Mobility Laboratory, EPFL
- Principal investigator: Michel Bierlaire
- Project manager: Prem Kumar

EPFL courses [3]

Spring 2012

Decision-aid methodologies in transportation.
- Level: Master
- Section: Civil Engineering
- Lecturers: Michel Bierlaire, Prem Kumar
- Teaching assistants: Jingmin Chen, Nitish Umang
- Webpage: http://transp-or.epfl.ch/courses/decisionAid2012
Optimization and Simulation.
- Level: PhD
- Section: Doctoral program in Civil and Environmental Engineering
- Lecturers: Michel Bierlaire, Bilal Farooq, Prem Kumar
- Teaching assistant: Nitish Umang
- Webpage: http://transp-or.epfl.ch/courses/OptSim2012/

Spring 2011

Decision-aid methodologies in transportation.
- Level: Master
- Section: Civil Engineering
- Lecturers: Michel Bierlaire, Prem Kumar
- Teaching assistants: Jingmin Chen, Nitish Umang
- Webpage: http://transp-or.epfl.ch/courses/decisionAid2011

MSc theses [4]

2012

MEETAWAY: Connecting People Optimally, François Anken (Mathematics)
- Supervision: Prem Kumar, Bilge Atasoy, Michel Bierlaire
- External expert: Pedro Faustino
A two-stage sequential linear programming approach to optimize security staff at Geneva Airport, Mahmoud Kharouf (Civil Engineering)
- Supervision: Michel Bierlaire, Nitish Umang, Prem Kumar
- External expert: Vincent-Ruben Jimenez

2010

Blind Booking Purchase Patterns: discrete choice analysis, Alexandre Khelifa (Civil Engineering)
- Supervision: Michel Bierlaire, Bilge Atasoy, Prem Kumar
- External expert: Prof. Laurie Garrow, Georgia Tech.
Modeling for Strategic Robustness, Peter G. Swartz (Civil Engineering)
- Supervision: Michel Bierlaire, Prem Kumar
- External expert: Prof. Christopher Zegras, MIT

Semester projects [3]

2011-2012

Optimizing Security Staff Operations at Geneva Airport, MAHMOUD KHAROUF

Supervision: Michel Bierlaire, Prem Kumar, Nitish Umang
Geneva airport is the second largest airport in Switzerland. Airport is capable of easily handling 80-100 landings and take-offs per hour. However one of the major bottlenecks today is the passenger handling capacity. The airport terminal area can handle up to 3000 passengers per hour. In recent times, passenger congestion is frequently building up at the airport. Because of the geographical reasons, it is not easy to expand the terminal building. As a result, it may be fruitful to attempt reducing congestion by efficient handling of the passengers and not letting the passengers wait too long to be serviced. Security screening is the most important area for departing passengers. Optimizing the operating costs for security personnel at airports is a complex problem due to a number of reasons. Each passenger and their corresponding hand baggage need to undergo security screening before entering the boarding gates. Even though the passengers and the baggage need to move together, the rate of service for the two can be vastly different. Security personnel work over specific shift times and need to be provided with suitable meal breaks. Staff members can work full-time or part-time, with a minimum of four hours per day. Passenger arrival pattern at an airport can be extremely uneven. Flight activities also tend to be non-uniform while passenger service expectations and staffing inflexibilities due to shift durations can make the problem even more complex. In this work, we would use the flight schedule and service criteria to develop a method to find optimal shift timings and the mix of full-time and part-time workers such that the overall costs are minimized and the service criteria conditions are fulfilled. Term Project (Master Project Pre-Study) Deliverables � Determine global parameters for passenger arrival rates, service times and shift times at different times of the day and days of the week for both passengers and baggages � Develop and implement a cost optimization MIP model with discrete time intervals Masters Project Deliverables � Adapt the deterministic linear model to account for non-linear passenger arrival and service rates and implement the same � Build a robust optimization model to capture vastly varying arrival and service rates. Determine the various ways to capture model stability with special emphasis on recoverability � Perform sensitivity analysis and compare the results of the stochastic model with simulation � Use the results to make recommendations: For example, create a separate queue or sub-queue for passengers without baggage, or passengers whose flights depart in 20 mins should be brought ahead of the queue, etc. � Develop and implement the model for staff rostering at the security screening Apart from expertise in modeling, the student is expected to be able to implement his model and write his own codes in a standard programming language, such as C or C++ Desired Masters Project Deliverables � Evaluate the tendency for staff to take leaves (including sick leaves) and vacation (subject to data availability) � Plan for contingencies in your model Project Organization The student would be expected to update us on the progress and revert to us for queries on a pre-decided day of the week. The student would be expected to update us on the progress and revert to us for queries on a pre-decided day of the week. A midterm presentation would be scheduled on Thursday, 10.11.2011. At the completion of the term project, a report will be delivered (both in paper as well as electronic form) before the 13.01.2012. The final oral presentation for the term project will be scheduled on 11.01.2012. Similarly, the Masters project would be due before the 01.06.2012 while the oral presentation for Masters project will be scheduled between 18.06.2012 and 29.06.2012 or a mutually convenient and agreed date. All the files, programs, codes, data and report associated with the project must be delivered before these date. All reports will be submitted in two copies to TRANSP-OR Lab and GVA Airport. References � Dowling, D., Krishnamoorthy, M., Mackenzie, H., and Sier, D. (1997). Staff rostering at a large international airport. Annals of Operations Research, 72:125-147. � Ernst, A., Jiang, H., Krishnamoorthy, M., and Sier, D. (2004). Staff scheduling and rostering: A review of applications, methods and models. European journal of operational research, 153(1):3-27. � Gilliam, R. (1979). An application of queueing theory to airport passenger security screening. Interfaces, 9(4):117-123.

Optimizing Train Design in Capacitated Railroads, Stefan Binder

Supervision: Michel Bierlaire, Prem Kumar
The problems of Train Design, Railroad Blocking and Train Assignment are fairly complex and often observed in the railroad industry. Efficient solution methods to these problems bring a huge potential to achieve enhanced operational performance and dramatically reduced costs. Blocking is defined as an activity where a set of shipments arriving at or commencing from a certain node station and departing to another particular node station, or further, are grouped together and sent across as the same train to minimize costs and exploit economies of scale. This problem has marked similarities with the airline scheduling which operates flights across a predetermined hub and spoke network. The problem considered here not only necessitates determining the �right� hubs and �right� trains to be scheduled on the network, but also scheduling the shipments on appropriate trains between the hub station yards and spoke station yards so that the overall costs are minimized. In the problem considered by us, we are given a network comprising a set of nodes and arcs. We are also given a set of shipments with their origin and destination nodes. We are given a range of costs such as the cost of car travel per mile, cost of train travel per mile, cost of starting a train, cost of grouping (also referred to as classifying or blocking) shipments at an intermediate station of a train, cost of train imbalance, cost of crew imbalance and the cost of a missed car that is not transported. It is also required that each train path overlaps one or more crew segments completely. Crew segment between two nodes will also always follow the shortest path between those two nodes. Thus a train cannot run on a section which is not on the path of a crew. Train imbalance is defined as the imbalance generated due to the fact that the number of outgoing and incoming trains at a node differ. Total train imbalance for the network is computed as the sum of imbalances at every node. Crew imbalance is generated due to the fact that a crew operates on a segment, but cannot find an operational train to return to their base. In addition to these considerations, there are specific requirements relating to the maximum number of trains that a shipment can travel on, the maximum number of blocking (or classifications or work events � as referred in the problem statement) allowed for each train, the maximum number of trains allowed on any arc and the limitation on the maximum train length and tonnage. The main objective of our efforts would be to find a cost minimizing set of feasible trains that operate on one or multiple crew segments completely. We would also need to determine the least cost assignment of shipments to these trains. Term Project Deliverables � Develop and implement a cost optimization single or multi-stage mixed integer program model � Solve the model using a mix of relaxations and heuristics and report results on two data sets � Prepare a comprehensive report on solution methods and future research tracks on this problem Apart from expertise in modeling, the student is expected to be able to implement his model and write his own codes in a standard programming language, such as Java or C# Project Organization The student would be expected to update us on the progress and revert to us for queries on a pre-decided day of the week. A midterm presentation would be scheduled on Thursday, 10.11.2011. At the completion of the term project, a report will be delivered (both in paper as well as electronic form) before the 13.01.2012. The final oral presentation for the term project will be scheduled on 11.01.2012. All the files, programs, codes, data and report associated with the project must be delivered before these date. All reports will be submitted in five copies to TRANSP-OR Lab, LUTS Lab, Dr. Prem Kumar and Mr. Burak Boyaci. One copy is for the student.

2010-2011

Optimizing Staffing Plans at Airports, François Anken (Mathematics)

Supervision: Prem Kumar
Minimizing operating costs for maintaining ground personnel at airports is a complex problem due to uneven flight activities, passenger service expectations and staffing inflexibilities due to shift durations. In this work, we would use the flight schedule and service criteria to develop a method to find optimal shift timings that considers non-productive time due to activity changeovers, the mix of full-time and part-time workers and passenger waiting time criteria.