Friday, July 24, 2020

Our Recent Research on Human Migration Networks, Climate Change, and Covid-19

The New York Times yesterday published an article, "The Great Climate Migration,"  which stated: As with much modeling work, the point here is not to provide concrete numerical predictions so much as it is to provide glimpses into possible futures. Human movement is notoriously hard to model.

I have been working on the modeling for human migration networks for over 20 years and, in the past year, with collaborators, I have returned to this important topic. Our research was motivated by real-world events. According to the United Nations Department of Economic and Social Affairs, Population Division, by the end of 2019 the number of people forcibly displaced due to war, conflict, persecution, human rights violations, poverty and economic inequality but also climate change and natural disasters, had grown to 79.5 million. Furthermore, the vulnerability of millions of international migrants may be exacerbated in crisis situations, as actually is the case now with the COVID-19, and, of course, by climate change.

In addition,  migration interactions will be the key to achieving the 2030 Sustainable Development Goals (SDGs) adopted by the member states of the United Nations. In the 2030 Agenda, 9 out of the 17 goals contain targets and indicators that are related to migration or mobility.

In the series of papers, we first set out to include the impacts of regulations on migratory flows and utilities, and took the perspective of migrants behaving in a user-optimizing manner, that is, choosing their locations, subject to the differential between the destination location utility and that in the origin location minus the migration cost. This led us to publishing the paper, "International human migration networks under regulations,"  in the European Journal of Operational Research:


This paper we then extended to include multiple paths between origin and destination nodes, with each path possibly consisting of multiple links. The paper, "Refugee migration networks and regulations: A multiclass, multipath variational inequality framework," was published in the Journal of Global Optimization:

We also introduced, for the first time, a system-optimized perspective for human migration, in which a central authority allocates migrants to locations in a way that is optimal from a societal perspective. In the paper, published in the International Transactions in Operational Research (ITOR):  "Human migration networks and policy interventions: Bringing population distributions in line with system optimization," we demonstrated how, through policy interventions, in the form of subsidies, a governmental body could ensure that, once imposed the migratory flows (and associated population distributions) would generate a system optimum, although migrants were behaving in a user-optimizing manner.  Those of you well-versed in transportation science can see the analogues.

Subsequently, we included capacities associated with the population locations of the multiclass migrants in the paper, "Capacitated human migration networks and subsidization." The paper has been accepted in the volume:  Dynamics of Disasters - Impact, Risk, Resilience, and Solutions, I.S. Kotsireas, A. Nagurney, and P.M. Pardalos, Editors, Springer International Publishing Switzerland, 2020. This paper shows that the results for the  policy interventions in ITOR also hold in the capacitated case.

And, in our most recent paper on human migration, "A system-optimization model for multiclass human migration with migration costs and regulations in the Covid-19 pandemic," also co-authored with Professor Patrizia Daniele of the University of Catania in Italy and her PhD student, Giorgia Cappello, we proposed novel utility functions associated with origin an destination nodes and also considered regulations as in the above work. The COVID-19 pandemic has dramatically  affected global mobility in the form of blockages, restrictions, and travel disruptions, as risk mitigation measures are being implemented by numerous countries. Indeed, the International Organization for Migration (IOM) reports that between 11 March 2020, when the World Health Organization (WHO) declared COVID-19 a pandemic, and 20 April 2020, the total number of movement restrictions implemented around the world has increased to more than 48,000! This paper is now under review in a special issues of a journal.

People since time immemorial have sought to identify better locations for themselves and their families. As The New York Times also noted,  our model offers something far more potentially valuable to policymakers: a detailed look at the staggering human suffering that will be inflicted if countries shut their doors.

Research on human migration networks will continue.

Tuesday, June 16, 2020

Postscript on My INFORMS Webinar: Blood, Sweat, and PPEs: Rescuing Perishable Product Supply Chains and Impacting Policy Through Analytics

First, I would like to thank the INFORMS Practice Section for the invitation to deliver the inaugural webinar in its Analytics Series, which took place last Friday. The title of my webinar was: "Blood, Sweat, and PPEs: Rescuing Perishable Product Supply Chains and Impacting Policy Through Analytics." 

As noted on the INFORMS Section's webpage: the goal of the webinar series is to bring awareness of the value of applying analytics to real-world problems. The series is organized by Dr. Patricia Neri of Bayer Crop Science and Dr. Carrie Beam of the University of Arkansas.


Also, special thanks to all those who were able to join in. I was thrilled to hear from colleagues in many different countries, who were able to Zoom in.

This blogpost is a postscript on the webinar with links to my presentation and to the full webinar, which is now on youtube, and answers to questions in the Q&A.

That morning began with getting ready for the virtual event.

The logistics of the webinar, which was carried out via Zoom, was handled by Beth West and Mary Leszczynski of INFORMS and it was exciting to have it be open to the public and to have the registration be free. 

We had had multiple practice sessions, since there were slides to be included prior to my presentation about the series as well as slides afterwards, providing a link to this blog and noting that the webinar would also be posted on youtube.

Dr. Neri gave a lovely introduction to my presentation.
In the webinar, I spoke about a variety of perishable product supply chains impacted by the Covid-19 pandemic, including: food, PPE, and blood supply chains, and also provided some hope based on convalescent plasma as a treatment, under the reality of competition.  I discussed both earlier relevant research as well as research that we have conducted on supply chain disruptions and resilience during the Covid-19 pandemic. And, I also spoke about the impact of analytics during the Covid-19 pandemic on policy, including our work on blood supply chains. I emphasized the importance of the work being done by our Operations Research and Analytics community and also highlighted inspiring younger generations.



The webinar is now also online, thanks to INFORMS. 



Dr. Carrie Beam expertly handled the Q&A.

And, as promised, since we did not get a chance to address all the questions, below I provide a list of questions, followed by my response. For completeness, I also include the questions that were "live."


Question from Don Mustard of Canada: Covid has exposed a global supply chain that was not prepared for a global pandemic. What is the role of government in reinforcing supply chains' structure against disaster, ensuring that disruption is minimized?

My answer: This is an excellent question. I believe that national governments must be involved in disaster mitigation and preparedness and clearly this pandemic is a healthcare disaster. First and foremost, the government must ensure that we are prepared for a worst case scenario, as we are are experiencing now. This is an extreme disaster given the impact and prevalence over space and time (unlike an earthquake, flood, tsunami, etc.).  Many of the supply chains that have been most severely disrupted now are being referred to as "critical infrastructure" and the associated workers are truly essential ones. The government should guarantee that we have adequate stockpiles of  PPEs and medical supplies as well as the capacity to produce them, including vaccines. Investing in food supply chains is also warranted. As I discussed in my presentation, labor in many industries, including food processing, has suffered in the pandemic, resulting in product shortages. Having healthcare for workers will keep everyone safer and make our supply chains more resilient.

Question from Dr. Angelika Leskovskaya of Southern Methodist University: Will it be possible to send slides and probably recording after the webinar?

My answer: The links to the slide and the recording of the webinar are given above. I will check with INFORMS about further broadcasting of the information. Thank you.

Question from Don Mustard of Canada: Perhaps could you discuss your thoughts on the concept that Covid didn't create problems in the supply chain, but rather, just exposed them... and what your confidence that we will learn from this (vs. revert to our historical patterns of behavior).

My answer: Clearly, the pandemic dramatically illustrated to everyone not only the importance of supply chains but also the need for flexibility, agility, and having multiple suppliers, among many other important characteristics. At the same time, the necessity of closing many businesses,  incorporating social distancing measures in production and processing facilities, dealing with employee illnesses and fears of contagion, modifying freight service provision, etc., put many additional stressors on the supply chains. I do believe that Operations Research and Analytics will be utilized and valued more by many organizations as a result of the pandemic because our tools are extremely useful and can identify vulnerabilities (as well as synergies) in supply chain networks. We (firms, organizations, governments) cannot turn our backs on the lessons learned.

Question from Dr. Duncan Klett, Cofounder of Kinaxis: It seems logical that national stockpiles should be filled to close to necessary levels, then supplies would flow through the stockpile so the oldest get sent out to hospitals for immediate use, keeping the stockpile "current."

My answer: Yes, one would think that that would be and should be the case. I believe that some were surprised that masks actually can, in effect, perish over time because their quality deteriorates. This should have been addressed and mitigated way before the pandemic hit us.  

Question from Dr. Amir Masoumi of Manhattan College: Once the volume of blood donations and transfusions across the US are back to "normal", in which direction do you see the blood banking industry moving with respect to balancing the supply and demand for blood products?

My answer: I believe that there will have to be more cooperation, rather than competition among blood service organizations. That was actually one of the themes in a paper co-authored with you and with Dr. Min Yu that I mentioned in my webinar presentation. Also, with the demand for convalescent plasma, obtained through apheresis of blood donations, as I had discussed in my presentation, which is emerging as a possible treatment for Covid-19, there is now some added hope for hospitalized patients battling this disease. There is competition now for the valuable convalescent plasma but, ultimately, there should be system optimization and allocation accordingly.


Question from Rishabh Bhandawat, PhD Candidate at the University of Buffalo: Would centralized inventory with some sort of sharing mechanism have helped with Covid? 

Answer: I think that definitely, yes, especially in the case of the National Stockpile of PPEs and medical supplies. However, as I had mentioned in the webinar, there were not sufficient amounts plus there was deterioration in the quality (hence, perishability) of many items, which exacerbated the shortages. We need a sufficient centralized inventory and management of the critical needs supplies along with a fair distribution to points of demand.

Question from Dr. Robin Lougee of IBM: Does Anna want to talk about the role of blockchain?

Answer: Time did not permit a discussion on blockchain.  However, how blockchain can influence supply chains in the pandemic would be an excellent topic for a future webinar. Thanks.

Question from Dr. Robin Lougee of IBM: What's the NEXT presentation in the series?

Answer: The next webinar will take place on July 10, 2020 and is entitled, "Inventory, Packages, Price Points and People: An Inside Look at leading Technical People." The webinar will consist of panelists who will address: "How do the best geeks in the industry motivate and manage their technical teams. The panelists will be: Dr. Pooja Dewan of Otis Elevator, Dr. Anne Robinson of Kinaxis, Dr. Mallory Freeman of UPS, and Dr. Pallav Chhaochhria of Citi.

Many thanks for all the great questions! During the Q&A there were also comments sent by Marino Biagini and by Teja Krasek (from Slovenia), which were very much appreciated.

There was a glitch at the beginning of the webinar, which was quickly corrected, by the projector unmuting the computer. The Chat facility was disabled by the INFORMS folks due to prior issues for security reasons. 

Being "first" in anything is always risky, but nothing ventured, nothing gained. And with technology and the Internet there is always the possibility of a disruption.

I like forward to further discussions and important contributions from our community during these challenging times and when the pandemic is past us.

Saturday, May 30, 2020

My Upcoming INFORMS Webinar: Blood, Sweat, and PPEs

The invitation came from Dr. Patricia Neri, who serves on the Board of the Practice Section of INFORMS. Would I be interested in giving the inaugural webinar in their Practice Series? Very quickly I agreed. There was specific interest in having me speak on perishable product supply chains in the Covid-19 pandemic. I have had multiple interviews in the media on this topic (radio, TV, and print) and it was an opportune venue in which to synthesize thoughts as well as earlier and recent research on supply chains and disruptions.

I have been working on the presentation slides for my webinar, which is entitled, "Blood, Sweat, and PPEs: Rescuing Perishable Product Supply Chains and Impacting Policy Through Analytics." The webinar will take place on June 12, 2020, with Q&A to follow. The webinar is open to the public and information on registration is available here. Joining me on the Q&A panel will be Dr. Patricia Neri and Dr. Carrie Beam (I thoroughly enjoyed brainstorming with both recently on the title!). Special thanks also to Beth West of INFORMS for handing the logistics for my webinar.
The World Health Organization declared the Covid-19 global epidemics an official pandemic on March 11, 2020, and, even before then, I was hard at work conducting research on disruptions to supply chains because of the coronavirus. On March 12, 2020, my article on the stressed blood supply chain and the coronavirus was published in The Conversation. To this date, the article remains the most read article by a UMass Amherst faculty member, published in the outlet over the past year. It was followed by an invited piece in the INFORMS Analytics Coronavirus Chronicles.

Perishable product supply chains, including a variety of food ones, PPEs (which are time-sensitive), a well as blood supply chains, are some of the supply chain networks that have been most severely impacted in the pandemic. In this webinar, I will discuss our earlier work and present research on such topics and, for the latter, I will emphasize new work that includes the inclusion of labor under different constraints in supply chains. I will also highlight a recent paper on convalescent plasma that I wrote with Dr. Pritha Dutta on what has become a unique market consisting of competition among nonprofits and profit organizations for plasma from Covid-19 survivors for therapies in those suffering from the coronavirus. Finally, I will describe how work in operations research and analytics is influencing policy on a national level in a significant way.

And, since several of you have asked, below, I have highlighted some of the recent media interviews that I have taken part in, which are accessible on the links below. Many thanks for the interest! Hope that you can join me for the webinar.

Interview by UMass Amherst

Article on the Isenberg School Website on Impact on Policy

NBC Boston TV News Interview on Meat Shortages

Radio Interview on Farm Talk

Diaper and Wipe Shortage Radio Interview - Los Angeles

Interview for The Verge on Algorithms in the Pandemic and Supply Chains

Interview in USA Today on Diaper and Wipe Shortages

Interview in Morning Consult on Collateral Damage in the Pandemic

Also, many thanks to the American Mathematical Society and to Mike Breen for hosting me on the podcast on supply chains and Covid-19.

Tuesday, May 12, 2020

Celebrating my 22nd PhD Student - Dr. Deniz Besik

The Covid-19 pandemic has called for new types of celebrations of the successes of our students, including virtual graduation ceremonies at colleges and universities.

Last Friday, UMass Amherst had  an exceptional celebration via a video tribute that included many luminaries from Massachusetts from politicians, to an astronaut and UMass Amherst alumna, as well as celebrities.

Last Friday, the Isenberg School of Management at UMass Amherst also hosted a virtual celebration via Zoom for our PhD graduates, and, among the 9 receiving their PhDs, was Deniz Besik.
Dr. Deniz Besik was my 22nd PhD student and her concentration at the Isenberg School was Management Science. I have chaired the doctoral committees of 12 females and 10 males.

Dr. George Milne, our PhD Director at the Isenberg School, organized the event, with assistance from Mike Korza.  Deniz's family was able to Zoom in from Turkey.

It was such a pleasure to write about Dr. Besik, who came to our program from Turkey, having worked also in Germany. My tribute to her is below. She will be joining the faculty of the Robins School of Business at the University of Richmond in Virginia, in the Fall.

The full brochure with information on all of our PhD graduates can be accessed from the Isenberg website here.

The Sunday before, Deniz and I put on our robes and, with help from friends, had the photos below taken, while practicing physical/social distancing.


Deniz had 6 papers published while a PhD student, which is a remarkable accomplishment, in such journals as the European Journal of Operational Research, the Journal of Global Optimization, and Socio-Economic Planning Sciences. Her multidisciplinary research on perishable food supply chains, with a focus on quality, as well as economic policy instruments such as tariffs and quotas, yielded fundamental tools as well as insights and helped to identify who wins and who loses in the ongoing trade wars, made even more relevant now with the Covid-19 pandemic.

Hard to believe that Dr. Besik defended her dissertation on March 6, 2020, just a few days before the World Health Organization declared the Covid-19 pandemic and the world changed.


Deniz excelled in the three dimensions of research, teaching, and service, all very relevant to her future success in academia. Deniz served as the President of the UMass Amherst INFORMS Student Chapter and was a very engaged and loyal member. The chapter's webmaster, Haris Sipetas, posted a tribute to her, and to her two fellow PhD graduates in Engineering: Rodrigo Mercado and Ekin Koker.

Congratulations to Dr. Deniz Besik! We look forward to celebrating your PhD graduation face to face before too long. Wishing all the 2020 degree recipients all the very best! Your grit and resilience will get you through these challenging times.

Saturday, April 4, 2020

Marking the 30th Anniversary of the Passing of Dr. Stella Dafermos, the Second Female PhD in Operations Research in the World

During the COVID-19 pandemic, many of us are hearing from relatives and friends, from far and wide, offering support during these extremely challenging times.

Last week, I heard from my Brown University room-mate, with whom I shared a dorm room for 2 years. She was also a fellow Applied Math major, with a love of Operations Research, and an exceptional ballerina from South America, who then became a member of Brown's women's crew team. I co-founded the Brown Women's track team.

My room-mate wrote to me: "Stella Dafermos has appeared on my horizon these days. I can see Stella, wearing her grey knitted vest, writing on the blackboard, remember? It may well be that we’re living one of those math models she was trying to explain back then."

And then in a follow-up message last week, she continued: "I have a memory, crystal clear in my mind’s eye: we were sophomores, we were in our room (4th floor Diman), I am looking at my notes from her latest class, literally turning the notebook upside down and sideways to see if any of it would make any sense, thinking I really don’t think this is for me..  you were changing into your running clothes, munching on an apple, you come over, eye the notes and say.. oh, yeah, there it is, that’s good! You’ll get it!   And off you go running. I didn’t get it, but later, much, much later, from Vedic texts where they teach how our reality is actualized out of infinite probabilities, well, now the value of those lessons is evident."

Interestingly, unlike my room-mate, I never had Stella while I was an undergraduate student at Brown but I would hear about her from other female Applied Math majors. 

Dr. Stella Dafermos, the second female to receive a PhD in Operations Research (OR), passed away on April 5, 1990, so we now mark the 30th anniversary of her passing.  She was the only female Professor in the Divisions of Applied Math and Engineering at Brown at that time, and I became her first PhD student. Although she passed away at the age of 49, her incredible legacy on contributions to transportation and networks, notably, continues. Her contributions were recognized in an obituary that I wrote for the journal Operations Research, the only female thus honored. Her PhD was from Johns Hopkins University in 1968, and she was surrounded by luminaries in OR there.
Below is the academic genealogy tree, with academic ancestors including Maxwell, Newton, and Galileo. It, in an expanded form, with my PhD students, hangs in my office for inspiration. You can see the list of my PhD students, with the latest, Deniz Besik, to be added soon, here.


And, in a very interesting blogpost by the esteemed Dr. Mike Trick, who happens to be not only a fellow Canadian by birth, but also my academic cousin, you can read more.

Stella passed away on a Thursday. I was that year a Visiting Scholar at the Sloan School of MIT, and, shortly after I received the phone call about her death, I gave a talk at the OR Center. Such resilience is needed now, more than ever. I recall Professor Jim Orlin coming to my office to support me. Interestingly, Dr. Les Servi, now of MITRE (and with whom I also corresponded this week), was on sabbatical at the Sloan School then, and also offered much appreciated support. 

My husband drove us to the funeral, which was on the following Saturday. I remember the daffodils at the cemetery on beautiful Blackstone Boulevard and also some snow falling. I always consider daffodils to be Stella's flower because of her surname "Dafermos."  I wrote a tribute to my "Academic Mother" here.  I also wrote a bit on my personal journey in another post, in which I recognised the 20th anniversary of her passing.

One of Stella's paper (on variational inequalities, of course) is among the most impactful ones published in the INFORMS journal Transportation Science in 50 years!

Wednesday, March 18, 2020

The Blood Supply Chain in the Coronavirus Pandemic

Much has happened since my most recent blogpost on March 7, which celebrated the successful PhD defense of my student, Deniz Besik.

On March 11, 2020, WHO declared a pandemic due to the coronavirus, which causes the respiratory illness now known as COVID-19.

As an operations researcher, who does research on various network systems, including perishable product supply chains, with applications in healthcare - blood supply chains and pharma supply chains, I had already been following a multiplicity of disruptions as the coronavirus was spreading globally.

In addition to the supply chain disruptions, I have also experienced professional ones as have virtually all academics worldwide as well as students.

I am on sabbatical now and was honored and delighted to have been invited to give seminars and plenary talks in multiple countries (Canada, France, Italy, and the USA, with others still on the horizon). These have all been postponed/cancelled causing not only disappointment but many foregone experiences, networking opportunities, and adventures.

But safety and health first, and we must do anything and everything in our power to mitigate the pandemic, and to flatten the curve.

I strongly believe that researchers, if at all possible, and if they have an inclination to do so, should write articles for the popular press. I saw the looming crisis in blood supply chains, having been following events in China and Iran, as closely as possible, because of COVID-19. I collected our relevant articles on blood supply chains (a topic we have been researching for the last decade), and impacts of disruptions, and wrote an Op Ed for The Conversation: How coronavirus is upsetting the blood supply chain https://theconversation.com/how-coronavirus-is-upsetting-the-blood-supply-chain-133424

The article has now been reprinted in numerous publications including: SALON, MarketWatch, NavyTimes, EconTimes, and many others. I have been contacted by individuals who wish to help out. I have reached out to medical professionals that I know at top medical facilities to see if plasma of those who have recovered from COVID-19 may be used as treatment, as has been tried in China, supposedly with some success, and is now being investigated at Johns Hopkins.

The research that we have done on the blood supply chain includes the modeling of the perishability of red blood cells; the investigation of a disruption due to a major disease outbreak, which would result in a decrease in eligible donors, as well as disruptions to capacities of testing and processing, that clearly can happen with personnel being quarantined and/or struck by the coronavirus now. Our papers have also explored competition for blood donors using game theory as well as the design of blood supply chains plus the modeling of multiple tiers and even the competition among blood service organizations. We have also worked on quantifying the potential synergy associated with the merging or teaming of blood service organizations as in the case of a disaster.

Also,  we wrote a book to unify some of the knowledge on perishable product supply chains.
It is important to note that respiratory viruses are not transmitted via blood and all those who have the facility and the capability should donate. Since my article in The Conversation was published, the situation has become even more dire with severe blood shortages being reported by the American Red Cross. Blood, unlike many other products, cannot be manufactured, but must be donated by willing donors. Blood service organizations need to make this process now as comfortable and as easy for donors, as possible, by expanding mobile unit coverage, for example.

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An update since the above post was published. Thanks to INFORMS Analytics for publishing my updated article to The Conversation piece in the Coronavirus Chronicles.

And now, as we move further into the pandemic, the possibility of utilizing convalescent plasma in different ways in providing potential therapies, is generating optimism, while, at the same time, there is growing competition among different organizations, and even profit-making ones, for Covid-19 survivors' blood plasma.

Saturday, March 7, 2020

Bravo to Deniz Besik on Her Successful PhD Defense

Yesterday, was a very special day. Deniz Besik, who is my 22nd PhD student, successfully defended her doctoral dissertation at the Isenberg School of Management. The title of her dissertation is: "Essays on Competitive Perishable Food Supply Chain Networks: From the Impacts of Tariffs and Quotas to Integration of Quality." I had the pleasure of chairing her dissertation committee, which consisted of Professors Ana Muriel and Hari Balasubramanian of the College of Engineering at UMass Amherst and Professor Priyank Arora of my department at the Isenberg School.

Although the defense took place at 3:30PM on a Friday afternoon, the room was packed with Deniz's friends and colleagues and guests who had come to support her. Some had traveled from Boston and NYC to come to support her. Dr. Pritha Dutta, who was my 21st PhD student, and is now a Professor at Pace University, came from NYC.
Deniz in 4 and a half years as a doctoral student published 6 co-authored papers, which is an incredible accomplishment. Below are images of first pages of some of the articles.


Deniz was recognized for her research with the 2019 Outstanding Doctoral Student Researcher Award from the Isenberg School and took part in the INFORMS, POMS, and DSI doctoral colloquia. And, we recently heard that she was elected into the Phi Kappa Phi Honor Society. The ceremony will take place in early April and the UMass Amherst graduation in early May (assuming such events will be able to proceed, given the coronavirus).

The audience had great questions, given the timeliness of the dissertation as well as the clarity with which Deniz presented the results in her dissertation. Below is a photo of now Dr. Deniz Besik with her committee members after her defense.
And we managed to take a photo of some of the folks in the audience who stayed until after 5PM to congratulate her.
She was presented with flowers and I also gave her a gift.
Then it was time for a celebratory dinner, which took place at Judie's in downtown Amherst.
Followed by a very special dessert with candle.
I might add that Deniz during her doctoral studies also taught classes and she even served as the President of the UMass Amherst INFORMS Student Chapter. She has accepted a tenure track Assistant Professorship at the Robins School of Business at the University of Richmond in beautiful Virginia. The rewards of being a faculty member are many, but one of the best is seeing a very deserving and hard-working student achieve her dreams. We all wish Dr. Deniz Besik much continuing professional and personal success as she begins a new chapter as an Assistant Professor!