Workshops
Spring 2018

Lightning Talks

Tuesday, March 27th, 2018, 4:15 pm5:00 pm

4:15 – 4:25 pm Samitha Samaranayake

Real-time optimization of large-scale micro-transit systems

Abstract: The rapid expansion of on-demand ride-hailing services has changed the transportation landscape in many cities worldwide. While these services provide a valuable service, as evident by their popularity, there are many questions regarding their scalability, efficiency, equity and negative externalities (e.g. congestion, pollution etc.). One way to mitigate some of these concerns is to consider high-capacity ride-pooling services, where many passengers share a vehicle simultaneously.  Operationalizing such a system requires the ability to efficiently match large groups of riders to a fleet of shared vehicles in real time, a computationally challenging task to solve at an urban scale. This work presents a framework for solving this problem at the scale of New York City, capable of routing ~450,000 passengers a day in real-time using a fleet of two to three thousand shared micro-transit vehicles of capacity four to ten. 

4:25 – 4:35 pm Florian Dörfler

Feedback Optimization on the Power Flow Manifold

I will focus on online load flow optimization of AC power systems in closed loop. In contrast to the conventional approach where an optimal power flow solution is computed offline before being applied to the system, our objective is to design an adaptive feedback controller that steers the system in real time to the optimal operating point without ever explicitly solving an optimal power flow problem. Our methodological approach is based on online algorithms for manifold optimization that can be applied in feedback with real-time measurements and actuation. We validate the performance of our approach in a detailed simulation case study.

4:35 – 4:45 pm Sen Li

Optimal resource procurement and the price of causality

Abstract:  We study the problem of procuring diverse resources to cover a random signal.  Two scenarios are considered: (a) the signal reveals itself causally, (b) the signal is revealed all at once by an oracle. Each case induces an optimal resource procurement cost. The ratio between the costs in these two cases is defined as the price of causality. we compute the price of causality, and discuss its applications in energy reserves and cloud computing.

4:45 – 4:55 pm Jannik Matuschke

Fare Evasion in Transit Networks

Fare evasion in public transit systems causes significant losses to the systems’ operators. In order to decrease evasion rates and reduce these losses, transportation companies conduct fare inspections to check traveling passengers for valid tickets. In this talk, we discuss a bilevel model for optimizing the distribution of these inspections in the network, taking into account the passengers' reaction.