Monday, October 18, 2021

It's Official - Announcement of Stella Dafermos Achievement Award in Transportation Science, Thanks to TSL Society of INFORMS!

This morning the business meeting of the Transportation Science and Logistics (TSL) Society of INFORMS took place in a virtual format. There were over 100 participants, with even Norway, Germany, and Israel represented!

I'd like to thank the President of TSL, Professor Mike Hewitt, for running a very professional, and swiftly moving, meeting at which there were many wonderful award announcements and professional updates.

It is now official - I have known about this for months but had to be quiet until the announcement today. 
I am delighted that the TSL Society is recognizing my PhD dissertation advisor, Professor Stella Dafermos, who, sadly, passed away in April 1990 at age 49, with an award in her honor - Stella Dafermos Achievement Award in Transportation Science. I was her first PhD student

I will be chairing the first award committee and am deeply moved and honored.

I'd like to sincerely thank the President and the Board of the TSL Society for recognizing this amazing female trailblazer and role model in this significant way.

I was asked to prepare a short speech highlighting her contributions. 




Stella made herstory/history, in many respects.  She was the second female recipient of a PhD in Operations Research in the US and was the first female Full Professor in Engineering and in Applied Mathematics at Brown University, which she achieved in 1982.

Her 1980 paper, "Traffic Equilibrium and Variational Inequalities," published in the INFORMS journal, Transportation Science, was among the list of 12 most impactful papers in the journal over its 50 year history, as of 2016. All these classic papers can be downloaded for free on the above link provided.


Stella Dafermos had the highest standards when it came to scientific research.  She was guest editing a special issue on Network Equilibrium of Transportation Science, when she passed away, so Professor Amedeo Odoni of MIT and I completed the editorial process and we also published an In Memoriam to Stella in the special issue.

As I said in my speech this morning, "One wonders how much the world has missed because of her untimely passing."

I leave you with a photo of  Stella with Professor George Nemhauser that I took in Tokyo at the Mathematical Programming Symposium, August 28 - September 2, 1988. Stella loved conferencing and I enjoyed travel with her very much as well as publishing with her in many journals, including Operations Research and Mathematical Programming as well as Transportation Science, among others.

When I informed Stella’s husband, Dr. Constantine Dafermos, the Alumni-Alumnae University Professor Applied Mathematics at Brown University,about the Stella Dafermos Achievement Award, he responded, “I am delighted, moved and also – on behalf of Stella – honored.” “I feel that establishing the prize is a major service to your field, as it will serve as a recognition of the contributions in the early days and as a reminder that women were among these contributors.”

Let's continue to do our very best to uphold the highest standards that she set.

Tuesday, September 21, 2021

Teaching Face to Face in the Pandemic - The First 3 Weeks

It has been exciting, and quite interesting, to be back to teaching face to face at UMass Amherst in the pandemic.

When the COVID-19 pandemic was officially declared by the World Health Organization on March 11, 2020, I was on sabbatical for that spring term, and, hence, was not teaching.

Last academic year the instruction was done remotely, except for a few classes at the Isenberg School of Management. Hence, I taught all my courses in the Fall 2020 and Spring 2021 remotely via Zoom. It was a novel experience, especially since I had never taught online before. With the right technology, coupled with a lot of energy and creativity, the courses actually worked out quite well. A big plus was being able to host remarkable guest speakers, who are top professionals, in classes (and the speakers did not have to travel but could Zoom in even from Europe). 

The students regularly showed up to my Zoom office hours and I got to know many of them as individuals. Quite a few continue to stay in touch, even though they have now graduated!

UMass Amherst has a vaccination mandate (with exceptions for medical and religious reasons) for students, faculty, and staff, so that has provided some reassurance even with the Delta variant. Of course, there are still hundreds who are not vaccinated.

Also, UMass Amherst has a mask mandate inside buildings and students have to be masked in classes (although, strangely, faculty do not, and this has been bothering me a lot but this policy, to date, has not been changed). I am teaching with an N95 mask my Transportation and Logistics course.

It is very clear to me that students are glad that the instruction is now face to face. The first two lectures (I have now taught for three weeks) I reminded the students that the masks must be worn so that they cover their noses and mouths. If a student needs to drink, then the student should leave the classroom, and do so outside the room. The students have been truly wonderful at complying. They care about the health and safety of all and doing their best so that we can continue to have the university open and classes conducted in person.

Some features of  "remote" learning remain, which are actually positives. Assignments, lecture notes, and homeworks are all posted on Blackboard. This saves paper and the environment and the grades are easy to calculate but the "marking" of the homeworks can be challenging since it is much easier to write on paper. The students have gotten used to submitting homeworks online and this positive feature remains.

Also, and this is also advantageous pedagogically, when we were teaching (and learning) via Zoom, the classes were recorded and I would post the videos on Blackboard. Students, could then go back to review the material. This feature was very convenient and helpful.

Now, each of my classes (I had to have a classroom switch, due to several issues, including broken windows and technology that did not work) is recorded via Echo 360. I post the videos of the classes on Blackboard. Last year, I taught synchronously on Zoom and I liked the fact that we had a set schedule, which provided a nice rhythm to the week with the class meetings and also office hours. The students very much appreciated that the classes were "live" and not prerecorded (asynchronous teaching and learning).

I emphasize to the students that they must let me know if they will be missing a class and that is certainly happening in the pandemic. Having recordings of class meetings helps, but being healthy and in class is the best. The courses I teach are quite technical and having students ask questions while the class is in session can save a lot of time and enhances learning. 

I make sure that a window is open and the door to the classroom as well for ventilation since a layered approach to minimizing risk and contagion is important. Even the vaccinated can transmit the Delta variant so one has to be very careful.

So far, the teaching in person experience (once I got a new classroom) has been enjoyable and rewarding, despite it being the pandemic. 

I receive many "Thank you!s" after each class, which makes my day. I hope to instill the passion that I have for the subject in my students.

I am sure that this semester will bring new challenges, but, so far, I am feeling, more or less, "safe" and I love teaching my Transportation and Logistics class and interacting with the students in person.

Now, if only my PhD student had gotten his visa in time, so that he could be my TA. He is scheduled to arrive now in Spring 2020.

Monday, September 6, 2021

Our Research on the Inclusion of Labor into Supply Chain Networks

On this Labor Day, September 6, 2021, I thought it appropriate to write this blogpost in celebration of labor in the pandemic. Indeed, the COVID-19 pandemic has vividly and dramatically shown the importance of keeping our workers healthy and safe in all sectors of the economy from agriculture to healthcare. Many worked tirelessly and some suffered tremendously to ensure that products were produced, transported, and then consumed. Essential workers have become our heroes from farmers and food processors to freight service providers, including truckers, to healthcare workers, educators, and many others. 

During the pandemic, I have been researching how to include labor into supply chain networks so that disruptions could be better quantified, appropriate wages identified, and, even more recently, how firms should invest in enhancing the productivity of their workers through enhanced health and safety measures. This research continues and has become a great passion of mine.

I am pleased that three papers of mine on the inclusion of labor have now been published. The first paper, "Perishable Food Supply Chain Networks with Labor in the Covid-19 Pandemic," was published in the edited volume: Dynamics of Disasters - Impact, Risk, Resilience, and Solutions, I.S. Kotsireas, A. Nagurney, P.M. Pardalos, and A. Tsokas, Editors, Springer Nature Switzerland AG, 2021,  pp. 173-193. A prepint of it can be downloaded here.

The second paper, "Optimization of Supply Chain Networks with Inclusion of Labor: Applications to Covid-19 Pandemic Disruptions (2021),  was published in the International Journal of Production Economics, 235, 108080.

This IJPE paper continues to be among the most downloaded from the journal website over the past couple of months, which demonstrates the interest in this topic. This paper focused on the healthcare product supply chains, including PPEs.

The above two papers are optimization models and capture different types of constraints on labor availability. 

My paper, "Supply Chain Game Theory Network Modeling Under Labor Constraints: Applications to the Covid- 19 Pandemic (2021), was published in the European Journal of Operational Research, 293(3), 880-891. It proposes a series of game theory models in which competition for labor by firms is also considered. This is something that we are seeing in the COVID-19 pandemic, which has different sectors suffering from labor shortages. 

I was greatly honored that the Editors of this journal selected this paper of mine for an Editors' Choice Award and the publisher has made the paper available for free from the journal website.

I have also spoken at multiple conferences about this research; most recently, at the MOPTA Conference organized by Lehigh University, which I enjoyed very much. The title of my plenary talk at MOPTA was: "Labor and Supply Chain Networks: Insights from Models Inspired by the COVID-19 Pandemic."


The above papers all acknowledge and thank essential workers. And, today, I extend my gratitude to laborers world-wide. 

Sunday, August 22, 2021

First Flights in the Pandemic and Impressions

We returned from the West Coast at 1AM this morning from Seattle/Tacoma. I had not flown since the INFORMS Security Conference in beautiful Monterey, California in February 2020. I had also not taken a "vacation" since way before then and, frankly, it felt good to put up the "I am away message."

In 2019 alone, I had given invited talks in Chile, Ireland, France, Greece, Colombia, and Mexico as well as in many parts of the US and had also been to Ukraine for an academic business meeting. I was, pre-pandemic, a frequent flier, and have missed travel tremendously. My travels, almost exclusively, involve professional travel but, this past Wednesday, it was time to visit family before we all begin another busy academic year of teaching.

My husband and I flew out of Bradley airport (in Hartford/Springfield) early last Wednesday morning on United and we had a connection in Denver. The flights we took yesterday, also through Denver, were actually rebooked from today and, thank goodness, that we did get rebooked since the last flight into Bradley that we were originally scheduled for got cancelled because of Hurricane Henri, the first hurricane to hit New England in 30 years. We always "dress up" when we fly and, believe me, one gets better service then. We got whisked through fast lanes on TSA check ins!

I am one of those travelers that enjoys the journey and I also love flying.

All the flights were jam-packed and I had a middle seat on all 4 flights. United was very efficient in boarding us, which certainly pleased me and there was only one kerfuffle with our online checkin yesterday and then the changing of our seat assignments so I was passing notes to my husband with the help of multiple passengers in our row (he got a window seat) to get messages to him.

I had many impressions on the flying and airport experiences in the COVID-19 pandemic. Despite announcements that everyone was to have their masks  covering both the nose and mouth, I saw quite a few masks below the nose in the airports and some folks seemed to dilly dally with their drinks and food to have their masks below their chins as long as possible.

I had packed extra masks in my briefcase (this was not professional travel but I still can't fly without my briefcase) and these came in handy since the gentleman yesterday next to me on the flight from Denver had his mask consistently slipping below his nose. His was very grateful for my mask and thanked me. I had a marvelous conversation with him (yes, I am one of those "talkers" on planes but I am genuinely interested in people and have made some amazing connections on flights - even a teaching gig at Harvard in Executive Education). He was a trucker he told me for UPS. As someone who will soon be teaching her Transportation and Logistics class, who could be a better seat-mate? He has been doing long distance journeys for UPS in the pandemic so the conversation was so interesting and informative (I could write a post just about it but my students will get to hear a lot). And, on the flight on Wednesday from Bradley to Denver, I had a top lawyer next to me, who had driven his daughter all the way to the University of Hartford, where she is a student! My husband teaches there, so the conversation was also amazing - plus, the lawyer has 4 children and was involved in the Amazon IPO! And, on the flight yesterday from Seattle to Denver, I was seated next to a student from Washington University who had been an intern at Amazon all summer and was flying from Denver to Newark to get home to Jersey City. He is a CS major focusing on hardware. So we chatted about his experiences at Amazon and also learning in the pandemic.

The lady on the other side of me on the last flight yesterday was cold, so I lent her one of my travel scarves to warm her up.

Outside of the student who sat next to me, everyone was flying for family reasons - they had not seen children or grandchildren for about 2 years - were now fully vaccinated, and could not put off living any more.

We wore N-95 masks throughout our travel on planes, taxis, and being in airports, and, when the lady behind us was coughing on the first leg, I offered her Ricola cough drops, which she declined, and said that she had "an allergy." I could go on about this but will stop here. It was time for us to double mask, which we did.

Tacoma was gorgeous - I could easily live there. I will share some photos at another time. 

And,  as I write this, we have torrential rains and high winds in Amherst due to Henri. There already are over 100,000 people without power in the northeast. While we were on the West Coast, I heard from many colleagues and friends as far as Hong Kong who were very  concerned about us making it back east because of Henri. Thank you for the thoughtfulness, which is so appreciated.

We managed to get some fresh produce at local farm stands but were shocked and disappointed that at the Cumberland Farms in northern Amherst very few were wearing masks, even people with children and we have a mask mandate now in public interior places in Amherst.

Thursday, July 22, 2021

Thanks to All Who Made Our 2021 Dynamics of Disasters Conference a Success!

The 5th International Conference on Dynamics of Disasters has now come to a close. It was Professor Panos M. Pardalos who had the vision to start this conference series. I have had the honor of co-organizing the last four of them. This year the conference was virtual due to the COVID-19 pandemic and was co-organized by Professors Pardalos, Ilias S. Kotsireas, Chrys Vogiatzis, and me, with support provided by Professor Fuad Aleskerov and Sofia Papadaki. The conference website has a link to the full program and information on the outstanding plenary speakers: Professor Maria Besiou and Professor Oleg Prokopyev, and Dr. Stavros Siokos and Dr. George Karagiannis. It was very appropriate and illuminating to have plenary speakers from academia, industry, and government, who shed light on the latest research as well as best practices. 

The plenary talks were truly inspirational!



This was a single stream conference, which worked very well. There were excellent questions and a lot of discussions. Speakers and participants came from many countries, including: Austria, Germany, Italy, India, Nepal, Russia, the UK and the United States! It was very special to have four of my former PhD students present: Dr. Deniz Besik of the University of Richmond, Dr. Pritha Dutta of Pace University, Dr. Tina Wakolbinger of the Vienna University of Economics and Business, and the plenary speaker, Dr. Stavros Siokos! Dr. Besik presented on our latest food supply chain research with disruptions due to the COVID-19 pandemic, which is joint work with Dr. Dutta. Dr. Dutta, in turn, presented on our convalescent plasma research, a paper that was very recently published in Operations Research Forum. Also, my PhD student, Mojtaba Salarpour, presented  our paper published in the International Journal of Production Economics. In addition, I presented a paper on refugee migration networks that was co-authored with Professor Patrizia Daniele of the University of Catania and Professor Ladimer S. Nagurney of the University of Hartford. Our paper had been recently published in the Journal of Global Optimization. Professor Daniele also presented a paper on UAVs and 5G for disaster relief, work with Daniele Sciacca and Gabriella Colajanni.

As Professor Stephan Onggo of the UK (he is originally from Indonesia and is heading the Ops-Relief project) said: Disaster Management is complex and requires many different tools. And, indeed, the conference talks demonstrated the utility and applicability of optimization and simulation tools, AI and Machine Learning, game theory, network science, Data Envelope Analysis, and even the analysis of Twitter. There was definitely a "network" theme in many of the presentations!

Special thanks to colleagues in Nepal, India, and Russia, who joined us despite the challenges with their time zones and the conference talk scheduling. I am so grateful to each and every speaker and participant for the knowledge that was exchanges and also for the very supportive community that we have been building across the miles.

I am very pleased that many new research ideas were generated and new connections made virtually across the miles. It was wonderful to have 3 INFORMS Fellows take part in the conference, Professors Pardalos and Vicki Bier and me!

Below is a virtual group picture of the conferees.



Professor Panos M. Pardalos closed out the conference with the following quote, which I leave you with, "Keep positive but test negative!"

Professor Pardalos, inspired by Dr. Siokos, who emphasized that trees are the only "technology" that removes carbon from the air, then showed us the book in the photo below. Dr. Siokos is the co-founder of Astarte Capital Partners, based in London, England, which invests heavily in forests around the globe.

And we will be co-editing a special issue of the journal Operations Research Forum on our conference theme. The call for papers can be downloaded here.

Friday, July 9, 2021

Busy Week with the EURO 2021 and the Dynamics of Disasters Conferences

My Supernetworks group has been hard at work preparing for conferences that we will be speaking at. This Sunday the EURO 2021 Conference begins. It is a hybrid conference, based in Athens, and goes from July 11-July 14. On July 16, the 5th International Conference on Dynamics of Disasters begins and will last through July 18. It was originally scheduled to be in person and also in Athens, but has turned virtual. I am co-organizing the latter conference with Professors Kotsireas and Pardalos and Vogiatzis with great support from Sophia Paradaki.

Interestingly, back in the summer of 2019, I spoke at EURO Dublin and we organized also a Dynamics of Disasters (DOD) Conference, which took place in Kalamata, Greece! I blogged about the great Dublin conference, where many photos can also be found.  Please also check out my post on the DOD conference in Kalamata, which was a big success and we even edited a refereed volume, which was published by Springer.

The 2021 EURO Conference has a very busy and interesting program. I was delighted to be invited by Ruth Kaufman to give a lightning talk in the OR and COVID session in the Making an Impact Stream. The Making an Impact Stream I spoke at (on a panel) in Dublin and enjoyed the experience and discussions immensely. My lightning talk is entitled, "OR and COVID-19: From Research to Policy." Also, our latest work on game theory and disasters will be presented (the talk has been recorded by my PhD student, Mojtaba Salarpour, since it was placed in an invited session but at 5:30AM EDT). The presentation is based on a paper of ours published in the International Journal of Production Economics (IJPE) in 2021. We thank Professor Tina Wakolbinger of the Vienna University of Economics and Business for inviting us to speak in this Humanitarian Operations session that she organized for EURO 2021.


One can definitely see that we have been heavily engaged in research on various supply chain network themes in the COVID-19 pandemic.

The Dynamics of Disasters Conference has an excellent line-up of plenary speakers: Professor Maria Besiou and Professor Oleg Prokopyev plus Dr. Stavros Siokos and Dr. George Karagiannis.

Our presentations at the DOD conference will include research done with Professors Deniz Besik and Pritha Dutta on food supply chains and disruptions in the pandemic; on convalescent plasma, based on a paper with Professor Pritha Dutta, recently published in Operations Research Forum, and on refugee migration networks - work done with Professors Patrizia Daniele and Ladimer S. Nagurney and based on a paper published in the Journal of Global Optimization. Mojtaba will also present our paper in IJPE presented at EURO 2021. I am looking forward to many interesting discussions and idea generation!




Looking forward to "seeing" many wonderful colleagues at these exciting conferences!

Monday, June 21, 2021

So Honored to Receive the Harold Larnder Prize from CORS (Canadian Operational Research Society)

It has been a whirlwind past two weeks, beginning with the CORS 2021 Conference, which was virtual because of the pandemic, and at which I was honored with the official receipt of the Harold Larnder Prize in a lovely award ceremony. Many thanks to the co-organizers of the conference, Professors Fatma Gzara and Timothy Chan, for the very special introduction and also thanks to the CORS President, Professor Michael Pavlin!


And, the Prize certificate arrived, just in time from Canada, so that I could share it virtually with those at the ceremony. 

The first time that the award was given was back in 1986. The full list of recipients is here and we created a collage of previous recipients, posted below.

I am only the second female recipient of this prize and now the only living one, since, sadly, Ailsa Land passed away on May 16, 2021, at the age of 93.  Quite remarkably, we honored her receipt of the Beale Medal (first female recipient of that award) with a panel on February 25, 2021, and both she and her husband were able to be virtually present. I provide a link to the video of the panel at which I had the honor of speaking and some additional information in a previous blogpost.

As part of the Harold Larnder Prize, I delivered the opening keynote talk, "Novel Supply Chain Network Models Inspired by the COVID-19 Pandemic: From Optimization to Game Theory," at the conference. I have made my slide deck available for viewing and downloading. 


A recording of my Harold Larnder Prize keynote  can be viewed here.

Some background on Harold Larnder, which I highlighted in my keynote:


The framed prize certificate now hands in my office for inspiration. Many thanks to the Canadian Operational Research Society for this great honor! Our great discipline of Operations Research was instrumental in WWII, and its rigorous methodologies and scope of applications have benefited businesses, governments, numerous organizations, including nonprofits, and societies. And, now, its creative minds and powerful tools are helping in the battles in the pandemic.