Friday, March 31, 2017

Fabulous Talk by Professor Ozlem Ergun on Restoration of Network Connectivity In Large-Scale Disaster Response Problems

The weather forecast for today was dire (and it is March 31) with many area schools in Massachusetts even closing early.

Luckily, the day was just gray with some cold drizzle, and our speaker, Dr. Ozlem Ergun from Northeastern University, made it from Boston to Amherst. We had invited her to speak as part of our great UMass Amherst INFORMS Speaker Series, which the Student Chapter helps me to organize. The chapter does a terrific job advertising the talks, handling much of the logistics, including a reception prior to the talk, and providing information on its website as well as a newsletter through an e-list. Special thanks to officers: Pritha Dutta, Deniz Besik, Ekin Koker, Destenie Nock, and Amro El-Adle, for their hard work before and after the event today!

Dr. Ergun's presentation was on a topic of great interest to me - Restoration of Network Connectivity in Large-Scale Disaster Response Problems. The Chapter President, Pritha Dutta, had prepared the nice poster below announcing the talk, which also made the UMass Amherst homepage under events and was advertised at the Isenberg School on our fancy electronic displays.
Professor Ergun has been involved in humanitarian logistics and disaster relief research for a long time and joined the faculty at Northeastern University after being on the faculty of Georgia Tech. She is especially known for her work on debris removal post disasters. Her talk today focused on the restoration of network connectivity, specifically, critical infrastructure, such as transportation networks, in order to enable service networks to become, again, operational. For example, think of the destruction of roads and bridges post a disaster such as an earthquake and one wishes to deliver relief supplies and personnel from points of supply to points of demand under such conditions. Which roads should be repaired in the sense of removing debris so that they become passable and network connectivity in order to accomplish desired emergency response tasks is restored? She noted that multiperiod models are needed since in a given time period one may have only a certain amount of resources available.  She emphasized that if you can't get rid of debris you can't recover (just think of Haiti post the earthquake). Emergency agencies provide guidelines but not how to do it!

She emphasized the importance of integrating operations research and network science, which I fully concur with. Her talk especially resonated since I teach and do research on humanitarian operations and disaster relief and have also co-authored the Fragile Networks book with my former Isenberg School doctoral student and now tenured Associate Professor, Dr. Patrick Qiang.

And, coincidentally, I was just teaching the Nagurney-Qiang network performance measure and importance indicator for both nodes and links in my Humanitarian Logistics and Healthcare class last week!

I very much like how Professor Ergun emphasized that it is not just the topology of a network (or graph) that matters, before and after destruction/deterioration, but also what services are provided on the network! Since operations researchers care about  a variety of activities on networks from transportation and logistical flows to even financial and informational flows, this is quite "natural" for us. I also would put this in the area of "supernetworks."

She shared with us a network betweenness measure which she had extended with her doctoral students and then took us on a fascinating journey of a case study of resiliency of Boston versus Manhattan (two of my favorite locations on the planet)! She also presented an optimization problem, which one would need to solve in seconds consisting of the maximization of the benefit of making the connections over the time periods, given supply and demand points, and a variety of constraints.

Professor Ergun brought several of her PhD students and members of Northeastern's INFORMS Student Chapter to UMass Amherst, which made her visit extra special since our UMass Amherst INFORMS Student Chapter members could interact with their "sister" chapter in (eastern) Massachusetts.

I hosted the lunch at the University Club and the service and food were fantastic. Although it is a Friday, I suspect that many others had cancelled because of the weather forecast, which did not come to fruition! We enjoyed the clam chowder and the salad with crab cakes and we shared the chocolate torte, lemon mascarpone cake, and the cheesecake, which we had with tea and coffee.

Professor Ergun made it back safely with her students to Boston.

Tomorrow is April Fool's Day and there is snow, again, in the forecast! Operations researchers are resilient and we are so grateful to Professor Ergun for coming to UMass Amherst to speak and for also bringing some of her students and chapter officers of the INFORMS Student Chapter at Northeastern University!