Student Spotlight: Ruby Abrams

In the summer of 2019, Applied Math 3rd year student Ruby Abrams joined the Graduate-level Research in Industrial Projects for Students (GRIPS) Team at Zuse Institute Berlin, working on the mobile ticket inspection project sponsored in part by the Deutsche Bahn Railway Company. 


We study the underdeveloped Inspector Scheduling Problem. The Deutsche Bahn want to to maximise the number of passenger tickets inspected given already set train schedules with their limited resources, the passenger ticket inspectors. We formulate this problem as a network flow and implement this as a Mixed Integer Programme. We account for lack of data by estimating Origin-Destination Matrices and discuss complexity of the problem. We obtain empirical results of run time of the algorithm as a function of number of inspectors and conjecture that this problem is NP-hard. We also propose heuristic methods to solve this problem. See link to research paper below: