Tuesday, October 24, 2023

Some Highlights of the 2023 INFORMS Conference in Phoenix

It is truly extraordinary that this year's INFORMS Annual Meeting attracted over 6,000 delegates to Phoenix. The conference took place October 15-28, 2023 and convened operations researchers and analytics professionals from academia, practice and government. All continents except for Antarctica were represented and the INFORMS President Laura Albert remarked that, next year, perhaps even someone from that continent will join us.

To me, INFORMS is about the people/members, and I especially delighted in seeing several of my former PhD students, who are now thriving as professors at various universities (Dmytro Matsypura at the University of Sydney in Australia, Deniz Besik at the University of Richmond, Shivani Shukla at the University of San Francisco and Sara Saberi at WPI) and having one of my PhD students (Dana Hassani) present at his first such conference the paper that we co-authored with Kyiv School of Economics (KSE) colleagues in Ukraine. It was published in the Journal of Global Optimization as the lead article in an issue and was on display at the Springer booth in the Exhibit Hall. We got to keep the stunning Journal of Global Optimization issue. It was also very special to see both my Labor and Supply Chain Networks book, published in 2023, and the Dynamics of Disasters book that I co-edited with Ilias S. Kotsireas, Panos M. Pardalos and Arsenios Tsokas on display at the Springer booth. Lovely to chat with Pardalos, his wife and son in Phoenix!

Seeing colleagues for the first time in person was also extra special since, in the pandemic, new connections were made virtually but only recently have the travel and the face to face exchanges become possible (and are so very welcome). The technical sessions and plenary and keynote talks were excellent and not all could be attended because quite a few took place "in parallel."

I thoroughly enjoyed various board meetings, including that of the INFORMS Magazine Editorial Advisory Board with Kara Tucker and committee members at 8AM on Sunday morning, as well as the Editorial Board meeting of the International Transactions in Operational Research (ITOR), led by its Editor, Celso C. Ribeiro. The Editorial Board meeting of the Journal of Global Optimization, whose Editor is Sergiy Butenko, was also very enjoyable and the food was excellent - thank you, Springer, the publisher!

It was an honor to present an invited paper and also to speak on two panels: one on optimization and community resilience and the other one - Meet the ITOR Editors! Thanks to Professor Nazanin Tajik of Mississippi State University for inviting me to speak in her session. I was so honored to even receive a gift and special note from her in appreciation. My presentation on defense critical supply chains and risk management can be viewed here. Our other presentations are posted also on the Supernetworks Center site. The resilience panel did not have panelists' slides but it was so good that it went way over and I missed the WORMS (Women in Operations Research and the Management Sciences) lunch! Thanks to Himadri Sen Gupta of the University of Oklahoma for organizing this panel and to his PhD advisor - Andres Gonzalez!

The business meetings were very well-attended and I especially enjoyed the Transportation Science & Logistics Society business meeting at which Hani S. Mahmassani received the Robert Herman Lifetime Achievement Award in Transportation Science.

The INFORMS Fellows luncheon at which the newly inducted Fellows were recognized was deeply engaging and pleasant. It was an honor to share a table with Roman Slowinski, who traveled with his wife from Poznan, Poland, and well as other colleagues, including Ben Lev and Candi Yano!

It was delightful to meet new colleagues and to reconnect with many others. I wish that I could list everyone that made this conference so memorable for me - you remain in my pleasant memories - thank you.

Congratulations to all who received awards! Extra proud that our UMass Amherst INFORMS Student Chapter was recognized with the INFORMS Magna Cum Laude Award.

Below is a collage constructed as a remembrance of some of the highlights. Many thanks to the organizers and to all those who took part.

Friday, October 13, 2023

Very Much Looking Forward to the 2023 INFORMS Conference in Phoenix!

The 2023 INFORMS Annual Meeting is on the horizon, and is taking place October 15-18 in Phoenix, Arizona. The program is filled with numerous sessions, keynote and plenary talks, business meetings, and many award and social networking events.

I look forward to seeing colleagues from around the globe and also quite a few of my former PhD students. Dmytro Matsypura, for example, will be traveling all the way from Sydney, Australia to take part in this conference! Shivani Shukla will be coming from San Francisco, Deniz Besik from Richmond, and Sara Saberi from Worcester. Zugang "Leo" Liu will be traveling from eastern Pennsylvania.

It is also very exciting that my present Isenberg School of Management PhD student, Dana Hassani, will be speaking at this INFORMS conference, which is his first. He will be presenting our paper, "Exchange Rates and Multicommodity International Trade: Insights from Spatial Price Equilibrium Modeling with Policy Instruments via Variational Inequalities," which is co-authored with Kyiv School of Economics colleagues in Ukraine - Oleg Nivievskyi and Pavlo Martyshev. The paper was recently published in the Journal of Global Optimization

I will present the paper, "Defense Critical Supply Chain Networks and Risk Management with the Inclusion of Labor: Dynamics and Quantification of Performance and the Ranking of Nodes and Links," which is now in press in the  Handbook for Management of Threats: Security and Defense, Resilience and Optimal Strategies, Konstantinos Balomenos, Major Antonios Fytopoulos, and Panos Pardalos, Editors, Springer Nature, 2023.

Our talks are prepared and I am honored and delighted to be also speaking on two panels.

The above resilience panel is organized by Himadri Sen Gupta and the ITOR Editors panel by the EIC of ITOR (International Transactions in Operational Research) - Celso C. Ribeiro!

I will also be taking part in multiple Editorial Board meetings and in the meeting of the Magazine Editorial Advisory Board (MEAB) of INFORMS that I am now chairing, with the outstanding support of Kara Tucker of INFORMS and committee members.

I look forward to the INFORMS Fellows lunch and to congratulating the newly elected members.

It will also be wonderful to see the UMass Amherst INFORMS Student Chapter receive the Magna Cum Laude Award from INFORMS at this conference. Congratulations to all the student chapters who will be recognized for their activities at the conference!

Information on the INFORMS Annual Meeting in Phoenix can be found here. Seeing all the exhibits at the Convention Center will be great fun, I am sure, as well as meeting conferees at the various events and even in passing.

And, on Sunday, October 15, for a while, I will take part in an NSF Workshop on Mobility at Arizona State University with both David Boyce and Hani S. Mahmassani speaking. I have forwarded a tribute to David Boyce to the workshop organizers.

I have to also take this opportunity to congratulate Hani Mahmassani since he will be recognized at the Transportation Science & Logistics (TSL) Society business meeting in Phoenix with the Robert Herman Lifetime Achievement Award in Transportation Science! Robert Herman was his PhD advisor at UT Austin and this award is so well-deserved. Hani is an elected member of the National Academy of Engineering. 

It will be a very exciting time in Phoenix and we will manage, I hope, with the 100 degree temperature!

Saturday, October 7, 2023

Traffic Paradoxes Continue to Fascinate

I have been reading the paper, "Bibliometric analysis and systematic literature review of the traffic paradoxes (1968–2022),"  co-authored by Jia Yao, Ziyi Cheng, and Anthony Chen, published recently in the journal Transportation Research B, 177 (2023) 102832.  It contains a very thorough, exhaustive compendium and analysis of a plethora of traffic paradoxes, beginning with the classical Braess Paradox (1968) paper. I had the honor of translating the 1968 paper from German to English, along with Dietrich Braess and my then PhD student Tina Wakolbinger. The translation, "On a paradox of traffic planning was published in Transportation Science in 2005, along with a preface that I wrote with David Boyce.

Below is a photo taken with Professor Dietrich Braess and Tina Wakolbinger, when we hosted him at the Isenberg School of Management after our translation was published in 2006.

2005-2006 was a very busy year for me since I was then a Science Fellow at the Radcliffe Institute for Advanced Study at Harvard University.

The Braess Paradox has inspired many researchers from different disciplines and, over the years, I have written several papers on this paradox and others, which I have co-authored with both PhD students and other collaborators. 

In the study by Yao, Cheng, and Chen, I was thrilled and humbled to see that I am the "top leading author with a minimum of five publications" on traffic paradoxes and that I am in some amazing scholarly company.

I have had the pleasure of working on paradoxes and the authors of this Transportation Research B bibliometric study have listed the top 50 cited papers, which include not only the translation paper of ours but also my work with my PhD advisor (now deceased) Stella Dafermos, Ding Zhang, and Qiang "Patrick" Qiang.

Below is a list of the 50 most cited papers that the authors compiled.

I'd like to commend Yao, Cheng, and Chen on their paper, which is an incredibly valuable resource, which, I am sure, will generate much additional research.

Below is a list of some of the papers that I have referred to either explicitly or implicitly in this post.


Braess, D., 1968. Über ein paradoxon aus der verkehrsplanung. Unternehmensforschung 12 (1), 258–268.

Braess, D., Nagurney, A., Wakolbinger, T., 2005. On a paradox of traffic planning. Transportation Science 39 (4), 446–450.

Dafermos, S., Nagurney, A., 1984a. On some traffic equilibrium theory paradoxes. Transportation Research  B 18 (2), 101–110.

Dafermos, S., Nagurney, A., 1984b. Sensitivity analysis for the asymmetric network equilibrium problem. Mathematical Programming 28 (2), 174–184.

Nagurney, A., 2000. Congested urban transportation networks and emission paradoxes. Transportation Research D 5 (2), 145–151.

Nagurney, A., 2010. The negation of the Braess paradox as demand increases: the wisdom of crowds in transportation networks. EPL (Europhysics Letters) 91 (4), 48002.

Nagurney, A., Qiang, Q., 2007a. A network efficiency measure for congested networks. EPL 79 (3), 38005.

Nagurney, A., Qiang, Q., 2007b. Robustness of transportation networks subject to degradable links. EPL  (Europhysics Letters) 80 (6), 68001.

Nagurney, A., Qiang, Q., 2008a. An efficiency measure for dynamic networks modeled as evolutionary variational inequalities with application to the internet and vulnerability analysis. Netnomics 9 (1), 1–20.

Nagurney, A., Qiang, Q., 2008b. A network efficiency measure with application to critical infrastructure networks. Journal of  Global Optimization 40 (1–3), 261–275.

Nagurney, A., Zhang, D., 1997. Projected dynamical systems in the formulation, stability analysis, and computation of fixed-demand traffic network equilibria. Transportation Science 31, 147–158.

Nagurney, L.S., Nagurney, A., 2016. Physical proof of the occurrence of the Braess paradox in electrical circuits. EPL (Europhysics Letters) 115, 28004.

And, in 2007, a paper that I co-authored with Patrizia Daniele, who was supported by Radcliffe as my collaborator, and with David Parkes (now Dean of SEAS at Harvard) was published! Full citation:

Nagurney, A.,  Parkes, D.C.,  Daniele, P. 2007. The Internet, evolutionary variational inequalities, and the time-dependent Braess paradox. Computational Management Science 4(4): 355-375.