Prem Kumar research projects

This page reports only the academic work registered in the databases of the Transport and Mobility Laboratory, and is not necessarily a comprehensive list of the work by Prem Kumar.

More information may be available here

Optimizing Staffing Plans at Airports

Sponsor: Transport and Mobility Laboratory, EPFL

Team: Michel Bierlaire (PI), Prem Kumar (PM)

Period: October 01, 2010-October 01, 2011

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.

Robust Optimization of Railway Locomotive Assignment

Sponsor: Transport and Mobility Laboratory, EPFL

Team: Michel Bierlaire (PI), Prem Kumar (PM), Francesco Piu

Period: October 01, 2010-September 30, 2011

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"

A Solution Technique for the Locomotive Refueling Problem

Sponsor: Transport and Mobility Laboratory, EPFL

Team: Michel Bierlaire (PI), Prem Kumar (PM)

Period: July 15, 2010-July 15, 2012

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.