A Lot of Great News from the Supernetworks Center

It has been a real privilege serving as the Director of the Virtual Center for Supernetworks at the Isenberg School of Management at UMass Amherst.

I founded the Center back in 2001 and,  in 2003, the Supernetworks Laboratory for Computation and Visualization was established. The Center and Lab have hosted many luminaries from the research and corporate worlds and even from the non-profit sector.

We have always emphasized scholarship and education and our website is regularly updated. It also provides a terrific timeline of visitors, research, talks given, and many other activities that the Center and Center Associates have been involved in.

I always say that, by working together,  we can accomplish so much more and I take great pride in the research that we have done on network systems addressing such important issues as: transportation and  network vulnerability, humanitarian and healthcare supply chains, financial networks and risk management, sustainable transportation, decision-making on complex networks, including e-commerce, and, more recently, even the redesign of the Internet to offer more Choices. We have tried to advance both applications as well as methodologies.

Our research and associated activities have garnered support from many different foundations, from the National Science Foundation to AT&T, the Rockefeller Foundation, the Institute for International Education, among others. I have also used funds from the John F. Smith Memorial Fund to support the Center's activities and its various missions.

As the 2012 year draws to a close, I am pleased to share with you the 2013 Winter edition of The Supernetwork Sentinel, which is the Center's newsletter.

All editions of our newsletter can be found and downloaded here.

Wishing everyone a safe, healthy, and prosperous New 2013 Year!

Thank you for your support!

Transportation Network Systems -- Their Glory and Vulnerability Revealed

Last night's episode of America Revealed, Nation on the Move,  was on our nation's transportation systems.

As a researcher and educator, whose passion has always been networks (and especially transportation and logistics), I knew that this was another PBS TV production that I could not miss.

I am also a bit biased, since its host, Yul Kwon, interviewed me in NYC for a video segment on the Braess paradox and gridlock, and the interview is now part of the production's extensive website for education purposes.

The segment last night highlighted both private and public transportation and included beautifully filmed segments on school busses, subways, airplanes, and even freight. The graphics were fantastic -- demonstrating dynamically the flows of various transportation modes on the networks.

Yul began by saying how he is fascinated by networks and systems and then reported on transportation from airplanes, a traffic reporter's helicopter, and even a school bus in Arizona.

I have always loved transportation and my readers know that I got my driver's license (yes, I passed my driver's test in Northampton, MA) only after becoming a Full Professor and a mother. But, then again,  growing up in Yonkers, I would walk to public transportation, and ride busses and subways in NYC. As a student at Brown University, and a member of the women's cross country and track teams, I could get to where I needed to by foot (or with friends would take the bus into Boston and ride Amtrak home for holidays). As a faculty member, many of the most interesting places required air travel, and I continue to love flying and collecting conversations and experiences throughout the journeys and my explorations at various destinations. Luckily, now I get invited to speak and usually someone else pays the tab (thank you).

I very much enjoyed the freight segment last night, with a focus on Chicago, where Amtrak, commuter trains, and freight trains all have to share the same tracks. I have written about the freight capacity crisis and competition for scarce resources and the U.S. for years has not been devoting the attention and financial resources that our critical infrastructure (especially transportation) needs. America Revealed also captured some of the history of transportation construction in the U.S. with poor decisions made, which now are being undone at much greater costs.


My students get it and repeatedly ask me why can't the U.S. have transportation systems with trains and busses similar to parts of Europe?!

Network Vulnerability in Large-Scale Transportation Networks

Transportation networks are the lifelines in times of peace and prosperity as well as during and post disasters.

From roads to bridges, and whether by land, air, or sea, and via different modes of transportation, such networks provide the connectivity for the movement of people, goods, and services.

When Professor Michael Taylor of the University of South Australia in Adelaide issued a call for papers for a special issue of the journal Transportation Research A on Network Vulnerability in Large-Scale Transport Networks, my co-author of the Fragile Networks book, Dr. Patrick Qiang, and I knew that, given the timeliness of this special issue, we hoped to make a contribution.

We are delighted that we have heard from Professor Taylor who has let us know that the special issue is now in production with the publisher of the journal, Elsevier.

The papers in the special issue are:

Jenelius, E and Matsson, L-G, Road network vulnerability analysis of area-covering disruptions: a grid-based approach with case study

Taylor, M A P and Susilawati, S, Remoteness and accessibility in the vulnerability analysis of regional road networks

Watling, D and Balijepalli, N, A method to assess demand growth vulnerability of travel times on road network links

Bell, M G H, Trozzi, V, Hosseinloo, S-H, Gentile, G and Fonzone, A, Time-dependent Hyperstar algorithm for robust vehicle navigation in time-dependent stochastic road networks

Qiang, Q and Nagurney, A, A bi-criteria indicator to assess supply chain network performance for critical needs under capacity and demand disruptions

Nagae, T, Fujihara, T and Asakura, Y, Anti-seismic reinforcement strategy for urban road networks

Snelder, M, Van Zuylen, H and Immers, B, A framework for robustness analysis of road networks for short term variations in supply

Knoop, V, Snelder, M, Van Zuylen, H J, and Hoogendoorn, S P, Link-level vulnerability indicators for real-world networks

According to Professor Taylor: These are all excellent papers and define the global interest in vulnerability analysis. The special issue should be of wide interest.

Our paper in this special issue focuses on critical needs product supply chains. Critical needs products are those products and supplies that are essential to human health and life. Examples include food, water, medicines, and vaccines. The demand for critical needs is always present and, hence, the disruption to the production, storage, transportation/distribution, and ultimate delivery of such products can result not only in discomfort and human suff ering but also in loss of life.

Critical needs supply chains also play a pivotal role during and post disasters during which severe disruptions can be expected to have occurred. Indeed, the past few decades have visibly demonstrated that disasters, whether natural or man-made, may severely damage infrastructure networks, such as transportation and logistical networks, may cause great loss to human life, and also may result in tremendous damage to a nation's economy.

In our paper, we develop a supply chain/logistics network model for critical needs in the case of disruptions. The objective is to minimize the total network costs, which are generalized costs that may include the monetary, risk, time, and social costs. The model assumes that disruptions may have an impact on both the network link capacities as well as on the product demands. Two diff erent cases of disruption scenarios are considered. In the first case, we assume that the impacts of the disruptions are mild and that the demands can
be met. In the second case, the demands cannot all be satis fied. For these two cases, we propose two individual performance indicators. We then construct a bi-criteria indicator to assess the supply chain network performance for critical needs. An algorithm is described which is applied to solve a spectrum of numerical examples in order to illustrate the new concepts.

Sustainability of Transportation Networks by Including the Critical Human Element -- Commentary for Resources for the Future

I just heard from Resources for the Future (RFF) that my policy commentary, Designing Transportation Infrastructure to Include the Human Element, has been published.

It is also posted on the RFF homepage (and should reside there, I am told, for two weeks).

Resources for the Future is a Washington DC non-profit policy think tank, which focuses on environmental, energy, and natural resources issues. The invitation to contribute a piece came after my SAMSI presentation on Sustainability: Methodology with Applications in Raleigh, North Carolina in September.

In my commentary (with a nice graphic included, compliments of Resources for the Future), I also discuss the Braess paradox and several instances around the globe. The translation of the famous Braess paradox (1968) paper from German to English, which Tina Wakolbinger and I, together with Professor Braess did, is cited in the commentary as well as the preface to the article that I wrote with David E. Boyce (whom I recently had the pleasure of seeing in Miami at the Regional Science conference). Both the translation and the preface appeared in the INFORMS journal, Transportation Science.

With 7 billion people now on our planet and with the number of cars and other vehicles growing globally, there is a lot that we can and must do together to minimize not only congestion but also environmental emissions.

Collective Intelligence, Successful Teams, and the Female Factor

Does collective intelligence exist?

This was the question that a group of researchers from MIT and Carnegie Mellon set out to answer and the results of their study have been published in the article, "Evidence for a Collective Intelligence Factor in the Performance of Human Groups," in the October 29, 2010 volume of Science.

Clearly, the "design" of groups and teams has implications not only for management and a spectrum of organizations but also for engineering and even military operations (and I would even add educational institutions, including universities).

I came upon a reference to this study in yesterday's Boston Globe, in an article written by Carolyn Y. Johnson, entitled: "Group IQ." The article contains an interview with one of the co-authors, Thomas Malone of MIT's Sloan School, and it also included comments from Iain Couzin of Princeton (who was a fellow panelist with me at the World Science Festival's Traffic panel in NYC in June 2009).

The Science article was co-authored by Anita Williams Woolley, Christopher F. Chabris, Alex Pentland, Nada Hashmi, and Thomas W. Malone.

Pentland is the author of the truly fascinating book, Honest Signals, and we had the pleasure of hosting him in our Speaker Series at the Isenberg School.

He will be presenting a tutorial at the SBP 2011 conference on March 28, 2011 at the University of Maryland.

I was sufficiently intrigued by the Globe article to go and read the Science article.

In the article, the authors define a group's collective intelligence, c, as the general ability to perform a wide variety of tasks. Interestingly, they found that:

The "c factor" is not strongly correlated with the average or maximum individual intelligence of group members but is correlated with the average social sensitivity of group members, the equality in distribution of conversational turn-taking, and the proportion of females in the group!

The moral from this research study and "bosses" should listen up: do not dominate the conversation and include females (may I even say "diversity" matters) in the group if you wish to enhance collective intelligence and problem-solving, since social sensitivity makes a quantifiable difference.

Interestingly, recently, I published a paper on the wisdom of crowds in transportation networks and the disappearance of the Braess paradox, which received a lot of media attention. I expect the intriguing issues being raised by such studies will stimulate further research. In the meantime, I am enjoying very much working with my fantastic and diverse team at the Virtual Center for Supernetworks!

The Wisdom of Crowds in Transportation Networks and the Braess Paradox

Is there a phenomenon of wisdom of crowds in transportation networks?

In the paper, "The Negation of the Braess Paradox as Demand Increases: The Wisdom of Crowds in Transportation Networks," just published in Europhysics Letters, volume 91, (2010), I establish that this is, indeed, the case.

Drivers act selfishly and independently in choosing their optimal routes of travel with no concern as to the effects of their choices on the effects of others or on congestion, which is known, in economics, as a negative externality. Such selfish behavior can lead to the infamous and counterintuitive phenomenon known as the Braess paradox in which the addition of a new road can actually increase the travel time for all! Hence, the removal of a road to traffic as has been done recently in Seoul, Korea and in NYC may actually improve the travel time.

Our research proves that even in networks in which the Braess paradox occurs that, at higher levels of demand, e.g., with more drivers on a transportation network, the new route will no longer be used, and, hence, the Braess paradox will be negated. This novel result suggests that there is a wisdom of crowds phenomenon taking place.

Since other networks, including the Internet and electric power generation and distribution networks, have features similar to that of congested urban transportation networks, this paper has important applications to the design of such networks, as well. Notably, it demonstrates that designers of critical infrastructure must capture the demands and the behavior of the users of the infrastructure in their designs since inappropriate designs may not only result in worse-off situations for all but, ultimately, in a lack of use of parts of the new infrastructure. Fascinatingly, it may also have applications to targeted cancer therapy.

These results are especially timely given the calls for increased investments in infrastructure in the US. Without appropriate planning, however, the so-called investments may actually be counterproductive. At the same time, our study demonstrates that 'if one builds, it does not mean that more will come!'

Investing in the Nation's Infrastructure but Doing it Right

In an interesting Op-Ed piece in The New York Times, Dr. Laura Tyson of the Haas School of Business at UC Berkeley, and a member of President Obama's Economic Recovery Advisory Board, is calling for a new stimulus package to invest in the nation's infrastructure.

My colleagues and I at the Supernetworks Center have been writing a lot on how to identify not only the costs of infrastructure degradation from our roads and bridges and even the Internet, from an economic and performance standpoint, but also on how to identify the effects of enhancement and investments by taking into consideration the behavior of those who will ultimately be using the infrastructure. In addition, it is imperative that the investments are made with cognizance of climate change and how best to adapt our infrastructure investments accordingly from transportation networks to supply chains and electric power generation and distribution networks.

Our paper, which contains highlights from our research and major findings, but in a more condensed fashion than found in our Fragile Networks book is entitled: "Fragile Networks: Identifying Vulnerabilities and Synergies in an Uncertain Age,"and it is in press in the journal International Transactions in Operational Research.

I just hope that if a new stimulus does get passed and even an Infrastructure Bank established, that economists, engineers, operations researchers and management scientists, and even environmental scientists, all work together so that what gets built, renovated, expanded, enhanced, and where, can have the greatest positive impact economically not only in the short-term but also in the long-term.

Transportation Network Robustness in an Era of Climate Change

There has been a lot of press lately, and justifiably so, on the recent multiday closure of the San Francisco Bay Bridge and the Lake Champlain Bridge (it looks as though this one will be permanently closed). Closures of such critical transportation links have played havoc on commuting times as well as on the local economies that they connected and bridged.

There has been little attention, however, given to the impact of the deteriorating transportation infrastructure on the environment.

Our paper, Environmental Impact Assessment of Transportation Networks with Degradable Links in an Era of Climate Change, which is the lead article in a forthcoming issue of the International Journal of Sustainable Transportation, provides quantitative measures to assess the impact on the environment of transportation infrastructure deterioration. It provides environmental impact assessment indices under alternative travel behavior (either system-optimal or user-optimal) and quantifies the environmental robustness of a transportation network subject to the deterioration of the roads, including their outright removal (as in the case of bridge closures or collapses).

The paper also demonstrates that travel behavior must be included in environmental assessments of transportation network robustness and the environmental impacts. In addition, and this is quite interesting, we demonstrate that system-optimizing behavior does not necessarily lead to reduced environmental emissions! Indeed, in certain networks, letting travelers behave selfishly and letting them determine their optimal routes of travel individually with no concern for negative externalities results in lower emissions than when a central controller routes traffic so as to minimize the total travel time!

Transportation networks are simply fascinating and counterintuitive phenomena associated with them from the Braess paradox on continue to provide important subjects for research, education, and, of course, practice.