IMA Institute for Mathematics and its Applications … › ... › files › AnnualReport2012.pdfThe Year in Review Fiscal year July 1, 2011, to June 30, 2012 Program year september

2012

2011

The Year in Review

IMA Institute for Mathematicsand its Applications

The Year in ReviewFiscal year

July 1, 2011, to June 30, 2012Program year

september 1, 2011, to June 30, 2012

www.ima.umn.edu

The 2011–2012 Annual Thematic Program focused on the “Mathematics of Information.” The decision to mount a year-long program centering on information was made nearly four years ago. The idea came from the IMA Board of Governors, who deserves credit for this foresight. Their decision put us way ahead of the curve—“Big Data” was not such an urgent topic back in 2008, and certainly was not something familiar to most mathematical scientists.

The rationale for doing something in data was simple. Massive amounts of data were being collected and stored at unprecedented rates, and the tools needed to extract useful information from them were lagging behind. Math-ematics is a key enabler in this grand endeavor, and we

needed to rally mathematical scientists to address this grand challenge. Putting together a scientific program at this scale was daunting. But thanks to the

reputation that the IMA enjoys, we were able to get a wonderful group of organizers. I am always amazed at the quality of the people who help provide the scientific visions of our programs. The outcome was a program that was both cutting edge and innovative.

The workshops were set nearly two years ahead of the thematic year. My main responsibility in 2010–2011 was to put together the personnel that would be the core researchers during the year. In this regard, I talked to a lot of people and recruited them to visit the IMA as long-term visitors. In addition, we also hired eight post-doctoral fellows to be part of the program.

All the hard work has paid off. There were visitors coming and going all through the year. Many came for a single

workshop while others stayed a month or more. What I liked best was the fact that nearly half of the visitors during the year were comprised of people who have never been to the IMA. The program was successful in connecting research groups who do not normally collaborate.

Of course, the long-term impact of the program will not be evident until a few years from now. Nevertheless, we have already seen some results.

The workshop on group testing in February 2012 brought together two communi-ties of researchers—from theoretical computer science and bioinformatics—that do not normally go to the same conferences. A wonderful outcome resulted from this workshop and is described in detail on page 9. A workshop on networks brought together groups of researchers who share common scientific challenges once the language barriers were broken down.

We also had a superb workshop on machine learning that was very popular. Videos from this workshop are among our most viewed. Of the many positive comments we received, most related to meeting new people with similar interests, connecting with people from other disciplines, and gaining exposure to new topics. Naturally, the IMA plans to follow up on further developments resulting from our investment.

Another outcome was a collaboration between Caroline Uhler (a first year postdoc) and Steven Wright (a long-term visitor), which has led to some surprising new results in biology. Read the full story on page 12.

Finally, 2012 marks the 30th anniversary of the IMA. As we celebrate 30 years of transformative mathematics, achievements, and collaboration, we recognize the contributions of each visitor who has walked through our doors, and we look forward to the next 30 years as we continue to create connections across disciplines, provide an engaging atmosphere for cooperation, develop new mathematics and new break-throughs, train the next generation of researchers and educators, and make each thematic year more successful than the one before it.

Cheers,

Fadil Santosa Director

From the Director

Taking a Bite Out of Big Data


1 30 years of Transformative mathematics

4 a mathematical celebration of John milnor

5 mathematics of information

6 Best-selling author Jeffrey rosenthal explores the World of Probabilities

7 Determining Better Data-Driven method analysis in a climate of Data overload

8 industry mentors Pair with graduate students for 2011 Workshop on math modeling

9 When group Testing meets coding Theory

10 reflections from one of the ima’s First Postdoctoral Fellows

10 candice Price: at the Top of Her game

11 Unsolved mysteries—rachel Ward

12 an analogous Pair

13 Topologist explores New Directions at the ima

14 Former ima Postdoc ruth Williams elected to Nas

15 Vazquez receives Presidential early career award

15 georgia institute of Technology Hosts algebraic geometry for applications

16 ima Video archive

16 ima at the great minnesota get Together

16 math and science Family Fun Fair

year in review • 1

30 YearsThirty years ago, in the fall of 1982, the institute for mathematics and its applications (ima) opened its doors. located on the Twin cities campus of the University of minnesota (UmN), the ima was founded by Hans Weinberger (director, 1982–1987), now a professor emeritus in the school of mathematics at UmN.

In response to the National Science Foundation’s (NSF’s) request for proposals to establish what it calls “a Math-ematical Sciences Research Institute,” Willard Miller, then head of the School of Mathematics and later IMA director (1998–2001); George Sell, currently a professor in the School of Mathematics and also former IMA associate director (1982–1988); and Hans Weinberger envisioned a mathematics institute that would be bold and run counter to the prevailing trends in mathematical research at that time. They proposed establishing a visitors’ institute where math-ematics focused on problems arising from other disciplines and from industry. They argued that such an effort would lead not only to increasing the impact of mathematics on

of Transformative Mathematics

other fields, but it would also lead to an enrichment of the mathematical research. This initial vision was realized in the creation of the IMA and continues to this day.

Breaking Down “silos” and crossing Disciplines

Sell recalled that “The proposal resonated with the mathematical sciences community who felt that as an academic discipline, mathematics was becoming ‘siloed’ into sub-areas that [did] not talk to each other, let alone to the world outside.”

george sell and Hans Weinberger

2 • institute for mathematics and its applications

The creation of the institute was a direct result of the NSF competition, and the IMA has successfully renewed its funding numerous times since. The IMA’s current NSF award, running through 2015, stands among the highest funded math projects in NSF’s history.

As a visitors’ institute, researchers with common interests from across disciplines gather at the IMA to collaborate on topics related to the annual theme. The focus of the year is always on an important area of applied research where mathematics is poised to make a difference or in a subarea of mathematics and its diverse applications.

The IMA’s 1982 thematic program was the first of several to focus on the math-ematics of materials science. Today, the IMA is widely credited for its major role in the development of this field.

“The IMA’s activity in the mathematics of materials has had a huge impact by nucle-ating then nurturing what has become a vibrant scientific community,” said Robert Kohn, professor of Mathematics at New York University.

Transforming the World through mathematics

Since 1982, the IMA has held 31 annual thematic programs, continuing to attract nearly 1,200 visitors who pass through its doors each year. “Thanks to the visionary leaders over the years, including Avner Friedman (1988–1998), Willard Miller (1998–2001), and Doug Arnold (2001–2008), the institute has grown to become one of the most innovative and prestigious math-ematical sciences institutes in the country,” said current director, Fadil Santosa. The IMA continues to offer a unique research environment for visitors, which fosters interdisciplinary collaboration. In the last 30 years the IMA has helped to transform the culture of mathematics, becoming a model for many other institutes in the United States and the world.

“The IMA impacts mathematicians from undergraduate to ‘grave’ and researchers from computer science to environmental science, from the social sciences to engi-neering, from biology to data mining,” says Doug Arnold. In fact, with its annual Public Lecture series, it now reaches middle- and high-school students. These lectures, given

by prominent mathematical scientists, reveal the importance of mathematics and how it impacts our daily lives, from e-commerce and privacy to health care and transportation.

The impact of the institute is far-reaching and long-lasting. Many thriving research communities have been launched by the innovative annual programs at the IMA. Partner corporations of the IMA, such as locally based companies Medtronic and Honeywell, and multinational partners like Schlumberger and Siemens, all tout the benefits of their connection with the IMA. Postdoctoral fellows who trained at the IMA are contributing to the health of science and technology of the United States. Closer to home the IMA serves as an important resource to the UMN’s research community—faculty and students from the College of Science and Engineering regularly participate in many of the IMA’s programs.

Nearly 300 postdocs have trained at the IMA. Many have ended up in top institu-tions and moved on to become research leaders in their fields. Some chose careers in industry and business where they achieved roles in leadership and upper management.

leaving a mark of excellence

in 2012, the ima moved to its new home on the third floor of lind Hall on the University of minnesota campus. an international architecture firm designed the remodeled space, which aims to enhance interaction among visitors and staff.

one especially exciting element of the design is an innovative “math wall”—etched with equa-tions and figures submitted by ima alumni and friends.

as the ima commemorates 30 years of accom-plishments, we acknowledge that our success is built on the contributions and achievements of each visitor who has passed through our doors, and each donor who has supported us since our inception.

Thank you for the overwhelming support we received during this fundraiser. all of the equa-tions submitted by the ima community have been gathered together to create this astonishing tribute to mathematics. We’ve included just a few of the submissions here with a comment on why it was chosen.

DonalD anD PhYllis Kahn We chose the Gauss-Bonnet formula because it is an early case of the blend of analysis and geometry.

C. EuGEnE WaYnE My first exposure to mathematical fluid dynamics was during my year as a postdoctoral fellow at the iMa. since then, a significant part of my research has focused on mathematical questions arising in the study of fluid motion so it seemed natural to pick this equation which describes the way the vorticity of a fluid evolves in two dimensions. The importance of understanding the evolution of the fluid vorticity was first emphasized by helmholtz in the mid-19th century, but understanding the solutions of this equation continues to be important today in circumstances as diverse as turbulence in fluids and hurricanes in the Earth’s atmosphere.


Indeed, through its postdoctoral program, the IMA guides the next generation of researchers and educators.

The IMA’s Industria l Postdoctoral Program was created in 1988 by Friedman, who felt that mathematics was undervalued in industry. The program pairs postdocs with companies who can use their exper-tise to improve its product lines. Postdocs devote half of their efforts on industry projects, working under the mentorship of industry scientists. The program was so successful that it is used as a model for the NSF’s Grant Opportunities for Academic Liaison with Industry (GOALI) program established in the mid-1990s.

In the early 1990s, IMA postdocs David Dobson and Gang Bao developed computa-tional methods that are still used routinely at Honeywell today. In particular, their work helped Honeywell to design a special type of optical filter used in head-mounted displays. At 3M, IMA postdoc Douglas Huntley worked on blood gas monitors used during surgeries, such as coronary bypasses. H is mathematica l work, wh ich wa s completed in 1994, provided the company with a very complete picture of the perfor-mance of the device so they could send it to

the market with absolute confidence. IMA postdoc Jay Gopalakrishnan developed a mathematical model of the temperatures achieved in ablation therapy of the heart with Medtronic in 2000. According to his mentor, David Francischelli, “His work led to a deeper understanding of the biophysics of tissue response and allowed us to provide better guidance to our customers who are using the devices—that is, surgeons. Ultimately, this product line has treated upwards of 150,000 patients.”

The ima FamilyOften times postdocs return to the IMA

as established researchers, offering their guidance and expertise to the new gener-ation of postdocs. For members of the IMA community, returning to the IMA to organize a program or a workshop is not uncommon. The ties that are created at the IMA are long-lasting and significant, bringing former visitors back to the insti-tute year after year.

Even after 30 years, there seems to be no end to the new challenges that lay ahead for the institute. The IMA looks forward to the future, where opportunities for interdisci-plinary collaboration abound.

RoGER lui The integral equation i placed on the math wall was the equation i studied in my Ph.D. thesis. i debated for a while between that and an equation from my more recent research on mathematics of molecular and cellular biology, which i started when i visited the iMa during my sabbatical in 2007 and 2008. i decided on the former because the latter is still rapidly evolving and the equations i study today will most likely not be the same a year later.

hannah anD ThoMas MaRKWiG Thomas and hannah spent a year at the iMa during the year on applications in algebraic geometry. it was a fantastic year and we will always keep the iMa in good memory. We both work in tropical geometry. hannah’s favourite math objects are tropical plane curves. it is a lot of fun to play with these combinatorial objects, and at the same time you can get amazing insights into algebraic geometry.

ima community gathers for anniversary celebration

on July 9, 2012, more than 100 members of the ima community, including former and current directors, visitors, organizers, board members, postdoctoral fellows, staff, as well as distinguished members of the college of science and engineering, the Department of mathematics, and more, gathered in celebration of the institute’s 30th anniversary.

Director Fadil santosa welcomed the group, acknowledging the hard work, dedi-cation, and commitment to excellence that has been at the core of the ima’s continued success. He then paid tribute to former directors Doug arnold, avner Friedman, Willard miller, and Hans Weinberger, noting each of their significant contributions during their directorships. He also shared stories about the ima’s impact on the mathematics community and gratefully acknowledged the many donors who made the new math Wall, as well as many other initiatives, from the public lecture series to the ima’s installation to be housed at the science museum of minnesota, possible.

at the event, the newly installed math Wall was also debuted, showcasing dozens of equations submitted by members of the ima community in the institute’s recently remodeled space on the third floor of lind Hall.


From January 30 to February 1, 2012, the IMA held its second annual Abel Conference, this year celebrating the mathematical legacy of John W. Milnor, a distinguished professor of mathematics at the Stony Brook University Mathematics Department and codirector with Mikhail Lyubich of the Institute for Mathemati-cal Sciences.

The Abel Conference series honors the Abel Prize Laureates and is a collaboration between the Norwegian Academy of Science and Letters and the IMA.

A 1951 graduate of Princeton University, Milnor was appointed to their faculty before even completing his doctorate, which he earned the following year (1954). His legacy as a theoretical mathematician is well worth celebrating. Milnor won the Fields Medal (1962), the National Medal of Science (1967), and the Wolf Prize in Mathematics (1989). Notably, he is the only person to have won all three AMS Steele Prizes (for seminal contri-bution to research in 1982, for mathematical exposition in 2004, and for lifetime achievement in 2011). And now, of course, the Abel Prize in 2011 for his pioneering discoveries in topology, geometry, and algebra. According to the Abel committee his profound ideas and fundamental discoveries have largely shaped the mathematical landscape of the second half of the 20th century.

The 2012 conference was an extremely well-attended event and according to one organizer, represented the “gathering of the clan” of those left from the “glorious days of topology in the 1950s

Second Annual Abel conference

A Mathematical Celebration of John Milnorand ’60s,” beginning with an introduction given by University of Minnesota Vice President for Research Tim Mulcahy and followed by a talk by Mark Behrens, Massachusetts Institute of Technology.

“Behrens’ talk brought us up to date on the question of which n-dimensional spheres have a unique smooth structure. They are n < 4, n = 5, 6, 12, 61. There may be more, but Behrens thinks it’s unlikely. This related to Milnor’s most famous work, showing that the 7-sphere has more than one smooth structure, and the later Kervaire-Milnor paper setting up the foundations for answering that question and for surgery theory,” noted Robion Kirby, University of California, Berkeley, an organizer for the recent conference.

The conference also included a presentation by Niles Johnson of a video shedding light on Milnor’s exotic 7-sphere, a lecture by Peter Kronheimer, and an overview of Heegaard Floer homology by Peter Ozsvath, among many others.

In addition, “Doug Ravenel gave us a beautiful PowerPoint presentation with all the bells and whistles (and photos) of the famous solution to the Arf-Kervaire problem due to Hill-Hopkins-Ravenel,” added Kirby.

Many of the lectures are available for viewing on the IMA website. Notably, videos from this conference have been viewed over 4,000 times. Photos from the conference can also be found online at www.ima.umn.edu/2011-2012/SW1.30-2.1.12.

The IMA gratefully acknowledges the generous support of IBM Research and the University of Minnesota for this annual conference series.


Each workshop was designed to be truly interdisciplinary, involving researchers from mathematical sciences, computer sciences, engineering, and other fields.

Information, broadly defined, plays an ever increasingly large role in our scientific and technological endeavors, as well as our daily lives. Collectively, we search the web over billions of times per day, we keep our medical records in digital repositories, we share videos and photos over the web, and we listen to music digitally. Our ability to collect, store, and generate vast quantities of data far outstrips our ability to analyze, process, and understand these data. Many scientific, engineering, and medical applications depend on our ability to handle enormous amounts of complex informa-tion. Network engineering involves massive datasets at high speeds, medical imaging generates large data with intricate geometric relationships, and astronomical observations include data at different wavelengths or spectral bands.

According to program organizer Anna Gilbert, “Current technology and scientific tools for information lag far behind our ability to collect enormous amounts of data, analyze it as efficiently as possible, and use that analysis to make sound, timely decisions. The gap between our tools and the volume of data we collect will increase unless we undertake a significant effort to improve these tools. Moreover, unless we clearly understand how we will use the extracted infor-mation, tools to do so will be useless. This gap widens at a time when it is increasingly critical for homeland security, internet security, and technical and biological insight that we analyze information quickly and that we derive meaningful information from it efficiently.”

More information, including videos of the lectures, is avail-able online at www.ima.umn.edu/2011-2012.

Mathematics of Information

annual Program organizers

inDERjiT s. DhillonComputer Sciences University of Texas at austin

anna GilBERTMathematics University of michigan

DianE laMBERT Algorithms and Theory google

ahMED h. TEWfiKElectrical and Computer Engineering University of Texas at austin

RoMan VERshYninMathematics University of michigan

The mathematics of information was the focus of the ima’s 2011–2012 ima Thematic year. The program gathered experts from numerical analysis, electrical and computer engineering, computer science, mathematics, and more to address the rapidly growing research areas facing the extraction of useful information from massive data sets.

2 0 1 1 – 2 0 1 2

annual Program Workshops high Dimensional Phenomena

large Graphs: Modeling, algorithms, and applications

large Data sets in Medical informatics

Group Testing Designs, algorithms, and applications to Biology

network links: Connecting social, Communication, and Biological network analysis

Machine learning: Theory and Computation

user-Centered Modeling

other ima Programs

hoT ToPiCs WoRKshoPs

september 7–9, 2011 instantaneous frequencies and Trends for nonstationary nonlinear Data

may 17–19, 2012The Mathematics of the new financial systems

sPECial EVEnTs

January 30–February 1, 2012second abel Conference: a Mathematical Celebration of john Milnor

may 30–June 2, 2012Workshop for Women in analysis and PDE

June 18–29, 2012new Directions short Course: advances in Random Matrix Theory

June 18–July 27, 2012MaXiMa interdisciplinary Research Experience for undergraduates

June 21–29, 2012nsf PiRE summer school: new frontiers in Multiscale analysis and Computing for Materials

July 9–13, 2012sage-Combinat Days 40


“I always thought mathematicians should be able to communicate with a wider audi-ence somehow. That was always in the back of my mind,” he explained. Lucky for him, his wife’s family consists of literary kin—writers, editors, and journalists—and they suggested he try writing something for the general public.

“I thought about it, and then one of them put me in touch with a literary agent,” he said. “We had a contract, and the next thing I knew I had to write a book!” he said with a chuckle.

When asked if it was difficult to draw examples from real life that resonated with people, Rosenthal admitted it was a chal-lenge, but it’s also been an adventure.

“It was not easy to write the book,” he explained. “I had to keep reminding myself that this was not a math textbook. That it was not for mathematicians. I had to think: How do these things come up in everyday life in a way that I can illustrate?”

Today, Jeffrey Rosenthal serves as a professor at the University of Toronto, dividing his time between his work on Markov chain Monte Carlo (MCMC) algorithms and interdisciplinary projects in which he collaborates with researchers from other departments, ranging from economics to psychology to speech therapy, to tackle problems using a stats-based approach.

“Through these projects, I’ve gotten to know a little about these other areas. It keeps things interesting.”

curiouser and curiouserAs a best-selling author, former University

of Minnesota assistant professor, and an expert on statistics, Rosenthal was invited to present in the IMA’s Public Lecture series. His book, Struck by Lightning: The Curious World of Probabilities, stands as an

entertaining introduction to statistics with examples ranging from weather predic-tion to winning the lottery to flying across the country to actually being struck by lightning.

His talk, entitled “The Curious World of Probabilities,” took place on the evening of April 25 on the University of Minnesota campus. The auditorium was filled with faculty, students of all ages, and folks just a little bit curious about probability.

Most people have been to a casino, but many wonder if they will come home a big winner.

Rosenthal said that casino-goers must remind themselves that most times we have no control and winning is completely out of our hands.

“It’s the spin of the wheel or the dealing of cards or it’s the video lottery terminal with the computer deciding; it always surprises me that people think they have control,” he said.

surprising statsLet’s say you are at a party with 40 people.

What are the chances that two people at that party will have the exact same birthday?

Rosenthal said that there’s about an 89% chance that some pair will have the same birthday.

“A lot of people are surprised by that. It’s because the number of pairs of people is a lot more than the number of people. If there are 40 people at a party you start saying, ok what are all the pairs? A with B and A with C and B with C and B with D…It’s just a simple formula. There are 780 different pairs you can make with 40 people, and with so many pairs, there is going to probably be some pair who share the same birthday,” he explained.

Throughout the lecture, Rosenthal offered many other fun everyday examples like this. Many times he even had the audi-


Public Lecture Series

Best-Selling Author Jeffrey Rosenthal Explores the World of Probabilities

How does one take the leap from statistician to best-selling author? rosenthal said he had the idea after attending many a party where he bored the crowd talking about his work. People just didn’t want to hear about it.

ence in laughter. Clearly, he’s mastered the art of making mathematics entertaining and accessible to the general public, his initial goal when writing his book.

2 0 1 1 – 2 0 1 2

Public lecture series

october 2011Naomi eHricH leoNarD / Princeton University

leonard provided a brief overview of collective motion in nature and robotics—how animal group behaviors inspire design for groups of

mobile, sensor-equipped robots, where demanding cooperative sensing tasks find their analogue in natural group behaviors, such as foraging and feeding. she also presented on the design of an adaptive ocean observation system using a fleet of underwater robotic vehicles and on motion and decision-making in bird flocks and fish schools.

november 2011aVi WigDersoN / institute for advanced study, Princeton University

in his talk, Wigderson surveyed some of the mathematical and compu-tational ideas, definitions, and assumptions which underlie privacy and

security of the internet and electronic commerce. additionally, he explained the fragility of the current foundations of modern cryptography and the need for stronger ones.

year in review • 7year in review • 7

As data acquisition becomes easier with advances in information technology, data becomes more complex and capacious. To extract the hidden information from the data, we must find ways to sort through it and analyze it. The applications for data analysis range from psychology, biology, and geophysics to art history, finance, biomedi-cine, and more.

“We are all after this very similar problem [of data analysis], but we all approach it from different points of view. In this small work-shop we can go deeper. We can explain how you can do it and ask what the advantages are. What are the limitations? Gradually, we can learn each other’s methods, find a common ground, and together, we can build a better tool,” workshop organizer Norden Huang, National Central University, Taiwan, explained.

According to workshop organizer Ingrid Daubechies, Duke University, we are getting drowned by data. But, what we are studying, she explains, for the most part, can still be better described and analyzed.

“There are more and more needles in haystacks, and these methods [of analysis] are good at finding needles in haystacks,” she explained.

Huang said that it’s time that we analyze data—take the data in parts, analyze the property of each part, and analyze the interaction between the parts—to build a better model.

“If you don’t have a good model, you don’t answer anything. We can no longer afford to just process data, we have to analyze it. This workshop is geared toward analyzing trends to build better models,” Huang added.

According to organizer Thomas Yizhao Hou, California Institute of Technology, even if you try to use differential equations to model the natural phenomena, there’s a lot of uncertainty on how to build the model, and it’s extremely difficult to solve these equations through computation.

“Today, we have a lot of good techniques to collect data. But we need mathematicians

to analyze it, to extract the hidden informa-tion. We have tools like Fourier transform, which is very useful for data compression but not very good for information extrac-tion. That’s why we need a more truly adap-tive tool, not a tool based on some a priori model. We need to listen to nature and then create the model,” said Hou.

This topic of trend determination is highly relevant today. There are many complex phenomena—natural, biological, financial, etc.—that require better analysis.

Huang cited global warming as a pertinent example.

“Everyone wants to find out how fast it’s warming—that’s a trend. In the past, a trend is always determined parametrically. How do you know the whole climate variation is linear, in a straight line? With this work on trend, we can better determine climate variation.”

Huang explained that the financial crisis is another trend that must be figured out. But how?

“We have to use data analysis because there are too many variables,” Huang explained. “Nobody can consider all of the variables. Without really detailed analysis of the data, we don’t know what’s going on. Studying of the gain is not a solution, for gains obliterate the trend. But a long-term trend is important.”

“In the past, we have not had a good defi-nition of frequency. The frequency is defined as inverse of the period: one over period is the frequency. This is a very, very crude way to define frequency. The frequency has to be defined by the instantaneous value. One application of this instantaneous value is to quantify nonlinearity. Right now, the definition of nonlinearity is qualitative, not quantitative. One can say ‘this is linear, that is nonlinear,’ but no one can say to what degree it is nonlinear,” Huang said.

According to Huang, once you know this there are many applications to which it can be applied. For example, to determine the safety of a structure.

From september 7–9, 2011, the ima presented a Hot Topics Workshop on instantaneous Frequencies and Trends for Nonstationary Nonlinear Data. This timely workshop gathered experts from several disciplines—data analysis, computing, econometrics, mathematics, and statistics—to explore the current issues involved with trend determination and instantaneous frequency.

“Any structure, before it fails, has to go through the stage of yielding caused by a nonlinear stress-strain relationship. Once it yields, its rigidity changes and its frequency changes. Long before the failure induced frequency changes, the wave form vibration will change due to the nonlinear straining, and that we can detect. We detect this from the instantaneous frequency,” Huang explained.

This can also be applied to the biomedical field. If one looks at the human body as a much more complicated “structure,” one can use instantaneous frequency to understand the signals—physiological and pathological—that your body gives off. And those signals have a trend, and can therefore be studied through instantaneous frequency.

“If you do not have instantaneous frequency you have a very rough, crude impression of the phenomena. But once you have it, you can really look into the data. So those give us a new handle. In the past, this concept was difficult, because we had no method to make the computation. Currently, the empirical approach is compu-tationally expensive. Now, computation’s not a problem. Therefore, there’s a lot of potential applications and potential markets for this new approach.”

Overall the workshop was quite a success. There were many lively and stimulating discussions during the lectures and the breaks. According to the organizers, partici-pants have already started to sketch ways in which they want to collaborate as a result of the workshop.

hot topics Workshop

Determining Better Data-Driven Method Analysis in a Climate of Data Overload

if you don’t have a good model,

you don’t answer anything.

We can no longer afford to

just process data, we have to

analyze it. This workshop is

geared toward analyzing trends

to build better models.”


Workshop

Industry Mentors Pair with Graduate Students for 2011 Workshop on Math Modeling

The first team, led by Stefan Atev with Vital Images, was given a problem relating to geometric and appearance modeling of vascular structures in CT and MR.

In terms of outcomes, his team was able to develop a better understanding of the best approach to their assigned problem: how to generate a three-dimensional model of a vessel from a set of cross-sections.

“We were avoiding the solution based on trade-offs determined during the early 2000s; both hardware and algorithms have improved dramatically since then and the prototype produced by the students convinced me of the feasibility of one approach,” Atev explained.

Atev said that, overall, the experience for him as a mentor was fantastic.

“All of the students on my team were highly motivated and intelligent and got excited about the project,” he said. “This was a good opportunity to manage and work with a larger team—normally I would have one intern, not six. It’s a good experience for technical people who do not manage large teams,” he said.

Thirty students participated in the ima’s fifteenth mathematical modeling in industry Workshop, held august 3–12, 2011. During the 10-day workshop, graduate students were divided into five teams by topic. each team was led by an industry mentor who guided the students throughout their stay, offering them advice, encouragement, and feedback as they worked through their respective problems.

He noted that his participation as a mentor was also a good introduction of his company to the students.

“It spread the word about us among students from some of the best universities around,” he added. Some students even expressed interest in doing an internship with Vital Images.

Mentor Thomas Grandine (Boeing Co.) also had an extremely positive experience.

“My team worked on a project to deter-mine the shape of curves whose integral of curvature squared is minimized. The students worked very hard, produced some very nice results, and wrote a cred-itable report on their findings,” he said. According to Grandine, “The report will prove useful to me as a resource, since it contains Euler Lagrange equations for a number of different problem setups, all carefully written down and organized in one convenient place.”

For Grandine, a pleasant surprise was the presence of all the construction going on around the University of Minnesota campus, providing his students real-world visuals of the applications they were producing digitally.

“As usual, the workshop provided an excellent opportunity for me to recharge the battery of my own career, basking as I did in the glow of all the young, agile minds around me. In short, the time was very well spent for me and promises to make me more effective in my normal job in the weeks ahead,” he noted.

A principal engineer with KLA-Tencor, Apo Sezginer’s team worked on the scat-tering of extreme UV light.

He explained that this is a unique regime where optical properties of materials are close to that of a vacuum, but the dimen-sions of scatterers are many times the wavelength.

“The conventional Born series fails in this regime,” Sezginer noted. “We extended the range of validity of the first-Born approxi-mation by a new algorithm.”

In the end, the concept worked for his team and they were delighted with the results.

The workshop was organized by richard J. Braun, gilad lerman, and Fadil santosa.


From February 13 to February 17, 2012, the IMA held a workshop on Group Testing Designs, Algorithms, and Applications to Biology. The organizers’ goal was to connect biologists and those studying bioinformatics with various mathematical communities because of the strong connections between group testing and coding theory.

Group testing, a method that was used in World War II to weed out syphilitic men called for service, pooled the recruits’ blood samples into groups, and the mixed blood samples are then tested. Because the infection

rate was so small, an efficient algorithm was devised to identify infected recruits. The number of tests needed to be performed is just a little more than the number of groups. Whereas, coding theory involves encoding data in such a way that even if parts are lost in the transmission, the entire message can be reconstructed by what is received. One of the most celebrated codes is the Reed-Solomon (R.S.) code which is used in encoding music onto a CD.

One tutorial, given by Atri Rudra (University of Buffalo), offered a computer scientist’s view of codes, group testing, and algorithms for identifying the significant items in a population through group testing.

What surprised the group was that what Rudra presented was essentially one of the designs that the biologists had been using. The biologists had worked out, in their own way, mathematical descriptions of the properties they were using of the design.

When the two groups were brought together, they realized that what they had been working on was essentially the same thing.

A large group of the participants got together during the workshop, fleshed out the exact relationship between the two models, started to figure out which properties of the design were useful, began proving what those properties translated to in coding theory, did some coding theory/combinatorial analysis to enlarge the collections of codes that would meet both groups’ desires, and then implemented one of the small R.S. designs that had previously not been generated before.

“We had a couple of people write little bits of code in a couple different languages to generate these R.S. codes. We were able to get really nice, clean ways of generating these matrices that the biologists have been using to pool their samples,” organizer Anna Gilbert said. “We generated them according to the right mathematical descrip-tion, one that makes it easy to modify various design constraints,” she added.

All of this transpired in time for one presenter to give a short talk on their findings on the last day of the workshop.

“It took getting two or three communities in the same room to figure out that we know a lot about this mathematically and we know a lot about how it works in the lab because we’ve tested it already,” said Gilbert.

And, according to Gilbert, the IMA is so successful because of its ability to bring these various communities together to stimulate collaboration and foster these types of interdisciplinary research efforts.

Remarkably, the group now has a nine-page manuscript that they’re working on, in addition to software that the biologists can use as a starting point for generating good group testing designs.

In terms of outcomes, Gilbert explained that this will assist one of the large-scale projects Yaniv Erlich (Whitehead Institute for Biomedical Research), among others, is doing on rare allele detection in certain populations. For example, conducting a pooled screening for carriers of certain genetic diseases, cystic fibrosis, Tay-Sachs, etc. Their discovery will help him to more efficiently pool more people and test them all at once.

Workshop

When Group Testing Meets Coding TheoryWhat happens when two communities come together at the ima? revelations, surprises, and new discoveries.

i was stunned to see the

speed at which they parsed

the latest papers mostly

from the computer science

and machine learning fields.”

“It was a pleasure for me to reconstruct the intellectual edifice we take for granted as background in an industrial setting,” he said.

Sanjiv Kumar, a research scientist with Google and a first-time mentor for the mathematical modeling workshop, said it was “an absolute delight” to be a part of this experience.

His team worked on finding a fast nearest-neighbor search in large high-dimensional databases. Even though the students did not have any background in this area, his team jumped right in.

“I was stunned to see the speed at which they parsed the latest papers mostly from the computer science and machine learning fields,” he said.

“In a short span of nine days, they were not only able to prototype several state-of-the-art hashing algorithms but also come up with novel modifications that gave the best results for the difficult pairwise search problem. They gave a new perspec-tive to the problem and strongly leveraged their applied math background to bring up new error bounds on the accuracy of the proposed method,” Kumar explained.

He noted that the program provides an excellent opportunity for math students to understand and possibly incorporate into their research the mathematical chal-lenges faced in the real world.


“Undoubtedly the highlight of my year at the IMA was the opportunity to interact on a daily basis with the other IMA visitors and postdocs,” he recalls. “There was an incredible number of interesting visitors who took part in the program that year and being able to meet with them and discuss common research interests was terrifically stimulating.”

Wayne explained that the role of mathematics in important applica-tions is better recognized today than when he left graduate school.

“I think that the IMA has played an important role in fostering that appreciation,” he explained. “The emphasis on applications is still a unique aspect of the IMA’s scientific program as is the Industrial Postdoc Program.”

Although Wayne holds a Ph.D. in physics, his visit to the IMA allowed him to expand his research in a

What happens when your Ph.D. advisor spends her sabbatical at the IMA? If you’re Candice Price, you get to tag along.

From August 2011 to August 2012, Price was in residence at the IMA along with her advisor, a professor at the University of Iowa, Isabel Darcy.

During her visit, Price, who received her Ph.D. degree in May 2012, was able to spend a great deal of time completing her dissertation research—“The oriented skein relation and a biological application”—a model for protein-DNA interac-tions using a well-known relation in knot theory.

For Price, the collaborative atmosphere was a highlight of her time spent at the institute.

“I was able to give a talk to mathematicians not directly in my field. I was also able to discuss my research with non-experts and gain much-needed

more mathematical direction. In fact, since leaving the IMA he has only been employed in mathematics departments.

“The wide range of contacts I made with other visitors during my year at the IMA has also been very important for my subsequent research career. In some cases that has involved direct collaboration on research projects, but in others it has just been the development of a circle of close, profes-sional relationships that I could draw on when I had questions or other issues in my career,” he said.

Wayne’s work today focuses on math-ematical questions that arise in fluid motions. One of his Ph.D. students—Anna Barry—actually wrote her thesis on this area. Notably, she will be a postdoc at the IMA during the 2012-2013 thematic year. Wayne said that he hopes her expe-rience will be as positive as his was.

feedback. It is a great environment for collabora-tion and allows you to see a diverse world of math-ematics,” Price explained.

Her favorite event from the past year was the second annual Abel Conference held in honor of John Milnor and his work in the field of topology.

“It was great to be surrounded by such well-known topologists; it really allowed me to expand my network.”

Price said her visit has had quite an impact on not only her research but her career.

“I’ve had a wonderful time at the IMA! I’ve met so many great applied mathematicians and learned a whole new area of mathematics,” she added.

The IMA wishes Price much success as she begins her three-year assistant professorship at the U.S. Military Academy in West Point, NY.

gene Wayne, now at Boston University, was among the first class of postdocs at the ima in 1982. according to Wayne, at that time, postdocs were not as common in mathematics, so for him, it felt like a real luxury to have a year to concentrate on his research.

research

Reflections from One of the IMA’s First Postdoctoral Fellows

research

Candice Price: At the Top of Her Game

gene Wayne

candice Price

anna Barry


One could say that Rachel Ward is a “regular” at the IMA.

Now an assistant professor at the Univer-sity of Texas at Austin, Ward, who graduated with her Ph.D. degree from Princeton in 2009, has visited the IMA five times since September 2011.

In March 2012, Ward came for a month-long stay to collaborate with a few of her colleagues also in residence at the IMA and to give a talk during an IMA workshop on Machine Learning: Theory and Computa-tion entitled Robust Computer-Enabled Tests of Goodness-of-Fit.

“I came for a whole month because I just really like it here. I enjoy the whole atmosphere, the open space, the white boards, all the postdocs and other long-term visitors, and everyone’s really friendly. The atmosphere here is really conducive to collaboration,” she said

Ward also decided to stay for a month to work with her colleagues Holger Rauhut, Felix Krahmer, and Mark Iwen—all in resi-dence at the institute at that time.

She and Rauhut are working on a long-term project in the area of compressed sensing.

“Holger and I have been trying to under-stand the limits of discrete uncertainty prin-ciples. The classic uncertainty principle says that the position and velocity of a particle cannot be simultaneously measured. Similar uncertainty principles apply to other pairs of properties for mathematical objects. Inter-estingly this ‘uncertainty’ implies that if you know that a function has a sparse or low-dimensional representation with respect to one basis, then you can reconstruct the func-tion exactly from very few measurements taken with respect to the incoherent basis.”

Ward says that one application of this area of “compressed sensing” is the potential for accurate MRI imaging from fewer scans. Discrete images naturally have low total variation, meaning that the differences in neighboring pixel values are almost every-where very small, with large differences occurring only around edges in the image.

Reduction in the number of MRI scans is possible because this “gradient” basis is incoherent with the “frequency” basis in which the MRI measurements are taken.

Ward and Rauhut have been working together on various aspects of this area since 2009. They’ve already published

several papers in the area, including “Sparse Legendre expansions via l1 minimization” and “Sparse recovery for spherical harmonic expansions.”

She said their working relationship is interesting because, despite the fact that they live so far apart, they are easily able to work efficiently when they are in the same place.

“We really optimize,” she said. With each paper they aim to achieve stronger mathematical results as well as more general results. “It’s a process of slowly figuring it out,” she said.

Ward shared that she is also working on a project with IMA Director Fadil Santosa and Iwen related to noisy bar code reconstruction.

“UPC bar codes (the codes on products in the super market) consist of a sequence of black and white bars. These can be inter-preted as a sequence of zeros and ones. But not every sequence of zeros and ones is a bar code.

Actually, bar codes make up fewer than .00000000000000001% of all the sequences of zeros and ones, and this is not necessarily taken into account in the current technology. We want to exploit this struc-ture to come up with more robust bar code reconstruction algorithms, or algorithms that can tolerate high levels of noise.”

In addition to spending a large amount of time collaborating with Rauhut, Iwen, and Santosa, Ward has also been working with Krahmer, who as luck would have it, was

research

Unsolved Mysteries—Rachel Ward

There are so

many problems

to understand, so

many connections

to be made. how

can i rest when

there are so many

mysteries to

solve?”

Rauhut’s postdoc in Bonn who now serves as a professor at Göttingen University.

The two are working to better understand the theory behind cross-validation, which is used extensively in learning theory and statistics for error-estimation from a limited data set, even though there are very limited performance guarantees.

“Netflix used this procedure—cross validation—to determine the winner of the Netflix prize. Netflix made a set of users and their movie preferences available to the public and challenged teams to come up with algorithms for predicting future movie preferences.” To determine the winning algorithm, Netflix tested the various algo-rithms on a second set of data that was kept hidden; the winning algorithm performed the best on this “hold out” data set. This is cross-validation. The question is: how well does the error on the “hold out” data set reflect the actual performance of the algorithm?

Ward said that they are trying to deter-mine when the procedure can be trusted to be correct.

With all of these projects, collaborations, conferences, and workshops on Ward’s plate, one may wonder how she does it all.

Her response?“There are so many problems to under-

stand, so many connections to be made. How can I rest when there are so many mysteries to solve?”

rachel Ward


research

An Analogous Pair Stephen Wright’s first visit to the IMA was in

1995, when he attended a workshop on optimiza-tion and control.

“That actually was a very important workshop for me, because I had done work on parallel-izing optimal control algorithms in the late 80s and early 90s. That was some of my very early research, but I didn’t pursue it far because there didn’t seem to be much of a market for it. It wasn’t clear that it was really necessary to make control algorithms run faster. But at that IMA workshop, I learned about a new paradigm called model predictive control, in which they need to solve these problems in real time.”

That IMA workshop actually ignited a long-lasting collaboration for Wright, which continues to this day.

“Jim Rawlings and I started working together directly as a result of the 1995 workshop. We have a collaboration that’s still going strong after 17 years. We have had numerous NSF and industry grants together. My collaboration with Jim was an important factor in my decision to move to Wisconsin. Jim and I, together with numerous students and visitors, have written papers together that have become influential and well cited. A very important part of my career came directly out of that workshop.”

Soon after the 1995 IMA workshop, Wright was invited to a workshop on chemical process control at Lake Tahoe, where he presented a paper on interior-point methods for model predictive control.

“That paper turned out to be very influential, starting a whole line of research in that area. It was a direct result of the IMA workshop,” he said.

During 2011–2012, Wright returned to the IMA for four visits during the thematic year on the Mathematics of Information, which coin-cided with his sabbatical from the University of Wisconsin, Madison, where he has served as a

professor in the Computer Sciences Department and the Department of Industrial and Systems Engineering since 2001.

His recent visits to the IMA, though short, enabled him to connect with a former IMA postdoc Caroline Uhler, who is now an assistant professor at the Institute of Science and Tech-nology Austria.

He and Uhler developed an immediate rapport and began working on a fascinating project.

“Caroline, whose main research interests are in algebraic statistics, had picked up an interesting problem while a graduate student at Berkeley, that dealt with the organization of chromosomes in cell nuclei. Nuclei have different sizes and shapes in different cells, and the chromosomes arrange themselves differently. The arrangements influ-ence biological function. This is a new and active research area in structural biology,” he explained.

While at Berkeley, Uhler modeled each chro-mosome as a sphere, which, according to Wright, is a rough approximation. Uhler developed an algorithm for calculating arrangements that minimize a measure of total overlap between the spheres.

“When she found out I did optimization, she told me about the problem, and she said that they really wanted to model the chromosomes with ellipsoids instead of spheres,” Wright explained. “The biologists believe that ellipsoids are much better models of chromosome territories. But trying to solve the minimum-overlap problem for ellipsoids is quite a bit more difficult than for spheres. It’s hard even to figure out how you quantify the overlap between two ellipsoids. You have to set up and solve a semidefinite program—whereas for spheres you can calculate overlaps with a few floating-point operations,” Wright explained.

Uhler and Wright joined forces in October 2011 and have been working on the project ever since.

This is a place where

important contacts are

made. it’s a career-

forming experience for

many of the postdocs

in residence. iMa is one

of the great modern

success stories in

mathematics research.”

stephen Wright


Isabel Darcy, an associate professor at the University of Iowa, arrived at the IMA in September 2011 to begin her New Directions Professorship.

“The IMA really is a great place to be. It offers a highly supportive environ-ment, and it’s the perfect place to get all of your work done. It’s also a great place to meet a lot of other people who are interested in the annual theme,” Darcy said.

Darcy, whose current research has been focused on studying the shape of DNA bound by proteins, decided to come to the IMA to spend a year as a New Directions professor because the 2011–2012 annual theme, Mathematics of Information, was a way to expand the research she was doing and explore new applications in her current field of research. She said while there will be some overlap in the mathematics, what she hopes to learn about are the new applica-tions. Moreover, she would like to be able to graphically model a distance table she created that shows the distance between knots based on the minimum number of crossing changes.

“This table tells you the minimum number of times mathematically this protein would need to act to convert one knot type to another knot type,” she explained.

This data can be visualized as a graph, and according to Darcy, she’s never actually studied the properties of this graph.

“This work relates to my old research, but it would be quite a different view of looking at this graph. While I am here, I would like to study this graph and learn new properties that would give some additional use to the DNA topology community,” she said.

For her, the IMA’s New Directions program was ideal because it allowed her to spend an entire year exploring a new area.

“You really need to spend the whole year at the IMA to immerse yourself in the research. The supplemental sabbatical support is definitely beneficial so that you can do that,” she said.

“Another great benefit is that you can bring your graduate students. That’s frequently a concern for those who are mid-career,” she added.

In addition, the professorships offer established mathematicians—typically mid-career tenured faculty at U.S. universities—an extraordinary opportunity to branch into new directions and increase the impact of their research by spending an academic year immersed in the IMA’s thematic program. Generally, participants learn new mathematics and applications, connect their research with important problems, and establish new contacts and collaborations. Wenbo Li, University of Delaware, also joined the IMA in 2011 as a New Directions professor.

An Analogous Pair

professorship

Topologist Explores New Directions at the IMA

“We started to get some interesting computa-tional results almost immediately. After leaving the IMA, we worked remotely on the theoretical results about convergence of the algorithm, and continued to run computations to refine the algorithm and try it on harder and harder problems. We had an almost-complete write up for a long time, and it’s only in the last week that we have gotten the final computational results. We both returned to the IMA this week to write up the final section,” he said. The collaborators finished and submitted their work a few days later.

The two have been sharing their work and presenting several talks in the last few months.

“It’s a very exciting topic to talk about because we are able to show movies and demonstrate how the algorithm works on simple cases,” he said. The connection to shape-packing prob-lems, a classical topic of research in discrete mathematics, gives the work additional appeal to broad audiences.

And the applications for this new discovery?Wright said that one goal of his work with

Uhler is to explain the observed arrangements of chromosomes on the basis of simple geometric principles, such as minimal overlap. He hopes that their methodology will complement the developments in biology because biologists are still in the early days of studying chromosome organization and its effects.

“This is an area that’s very much in its infancy,” explained Wright. “We are showing our work to the biologists to see what they think. Hope-fully, it will help guide their future experiments in this area.” After Uhler sent the completed manuscript to one of the leading biologists in the area, Thomas Cremer, he quickly invited her to visit his lab in Munich for further discussions.

The pair recently made another exciting new breakthrough that took their research one step further.

“Caroline found a very recent article in the biological literature that observed that homolo-gous pairs of chromosomes tend to be farther apart than the others. About six weeks ago, we modified our formulation accordingly, and started to get results that are much more like what the biologists are observing experimentally, so we were very excited about that,” Wright said.

For Wright, the IMA was instrumental to helping forge this collaboration, but he notes that he’s not the only one.

“The IMA has touched the professional lives of many people, and I am sure my story has been replicated many times,” he said. “This is a place where important contacts are made. It’s a career-forming experience for many of the postdocs in residence. IMA is one of the great modern success stories in mathematics research.” isabel Darcy (center) with graduate students mary Therese Padberg (left) and candice Price (right).


Ruth Williams, who currently serves as a distin-guished professor in the Mathematics Department at the University of California, San Diego, was recently elected to the National Academy of Sciences (NAS).

Williams says she was deeply honored to find out she had been elected to NAS—one of the highest honors given to a scientist or engineer in the United States.

Williams has had a long relationship with the IMA, beginning as a postdoc in the spring of 1986, shortly after she received her Ph.D. in mathematics from Stanford University in 1983. She then continued her work at the IMA as a participant and co-organizer for many workshops and programs as well as serving as a member of the Board of Governors (2003–2006).

Williams was a postdoc during the 1985–1986 Annual Thematic Program on Stochastic Differential Equations and their Applications. The organizers for the year were D. Stroock, W. Fleming, T. Harris, P.-L. Lions, S. Orey, and G. Papanicolaou. Notably, four of these organizers subsequently became members of the NAS and one was awarded the Fields Medal.

“For me, one of the great advantages of IMA workshops is that they provide the opportunity to learn firsthand the latest developments on an exciting research topic in the mathematical sciences from the key players in several different disciplines. As a postdoc at the IMA, I had the opportunity to hear lectures and to interact one on one over an extended period of time with leaders in the field of probability and its applications. In addition, I got to know other junior researchers in my field. Subsequently, I have collaborated with some of the participants and I have maintained contact with many over the years,” she explained.

The final workshop of that year focused on Stochastic Differential Systems, Stochastic Control Theory, and Applications and featured several talks involving viscosity solutions of Hamilton-Jacobi-Bellman (HJB) and HJB-Isaacs equations.

Kudos

Former IMA Postdoc Ruth Williams Elected to NAS“This was at a time when the new theory of

viscosity solutions was still under development and had barely begun to percolate to the community of researchers interested in applications involving stochastic control. This workshop was instrumental in disseminating this important new theory to that community,” Williams explained.

According to Williams, the article by J. M. Harrison in the conference proceedings (IMA series, volume 10) has often been cited by subsequent researchers as the seed for research on diffusion approximations for scheduling control in stochastic networks.

Returning to the IMA during the 1993–1994 Thematic Year on Emerging Applications of Prob-ability, Williams attended a workshop that, for many researchers, was the first time they had heard surprising examples by Lu-Kumar, Rybko-Stolyar, and Bramson, which showed that multiclass queueing networks could be unstable even when a natural traffic intensity condition was satisfied.

“Participants heard of ongoing efforts to under-stand the stability behavior of such networks based on a preprint of Jim Dai, which showed that fluid models could be used to dramatically simplify this task,” she said. “Since then, a deep understanding of the stability and heavy traffic performance of multiclass queueing networks, and the critical role that fluid models play in this, has been developed by researchers who attended that workshop. In fact, Maury Bramson and I spoke of our cooperative work on such develop-ments in our invited talks at the 1998 International Congress of Mathematicians held in Berlin.”

She noted that she attended the March 1994 work-shop which featured a talk by Walter Willinger. She said the work of Willinger and his collaborators led to subsequent intense activity aimed at measuring, modeling, and controlling traffic in telecommunica-tion networks. Notably, the IMA highlighted the developments in this area by hosting Hot Topics Workshops on Scaling Phenomena in Communica-tion Networks (fall 1999) and Mathematical Oppor-tunities in Large-Scale Network Dynamics (summer 2001).

for me, one of the

great advantages of

iMa workshops is

that they provide the

opportunity to learn

firsthand the latest

developments on an

exciting research topic

in the mathematical

sciences from the

key players in several

different disciplines.”


Mariel Vazquez, a former long-term visitor at the IMA during the institute’s 2007 Thematic Year on Mathematics of Molecular and Cellular Biology and an associate professor of mathematics at San Francisco State Univeristy, recently received the Presidential Early Career Award for Scientists and Engineers (PECASE), the nation’s highest honor for researchers in the early stages of their careers.

PECASE recipients are awarded for their innovative research and commitment to community service. Vazquez is a pioneer in the burgeoning field of DNA topology, specializing in the applications of topological methods and computational tools to the study of DNA packing, DNA-protein interactions, and DNA rearrangements.

Kudos

Vazquez Receives Presidential Early Career AwardToday, Williams’ research interests lie in

probability stochastic processes and their applications; her current research is concerned with developing new theories and applications for stochastic networks.

Williams noted that the IMA has played an important role in bringing together researchers from several different academic fields and from industry, and in holding timely workshops featuring new theoretical developments and new application areas as they have arisen in her particular area of expertise—stochastic networks.

“The growth in quantitative modeling in molecular biology is an emerging area of interest for stochastic networks,” she said. “And the IMA has been helping catalyze research in this area. For example, in spring 2008, as part of the thematic year on the Mathematics of Molecular and Cellular Biology, the IMA featured a Hot Topics Workshop on Stochastic Models for Intracellular Reaction Networks.”

Looking to the future, the IMA Workshop on Stochastic Modeling of Biological Processes, to be held in spring 2013, will bring together researchers from a variety of fields to share the latest developments on this very active topic.

In her recent work, Williams has analyzed models of the Internet to understand the entrainment effects of using fair bandwidth-sharing policies, and has used insights from queueing theory to study coupled enzymatic processing in protein networks, in collabora-tion with researchers in synthetic biology.

Williams is a fellow of the American Academy of Arts and Sciences, the American Association for the Advancement of Science, the Institute of Mathematical Statistics, and the Institute for Operations Research and the Management Sciences. She has been a U.S. National Science Foundation Presidential Young Investigator, an Alfred P. Sloan Fellow, and a Guggenheim Fellow. She is past president of the Institute of Mathematical Statistics, a major professional society for those doing research in probability and statistics.

2012 Pi Summer Program

Georgia Institute of Technology Hosts Algebraic Geometry for Applications

From June 18 to July 6, 2012, the Georgia Institute of Technology (Georgia Tech) hosted the 2012 Participating Institution (PI) Summer Program, Algebraic Geometry for Applications. The program, geared toward graduate students of PIs, covered techniques and algorithmic methods from algebraic geometry that are making an impact on applied mathematics and engineering.

“Algebraic techniques provide new approaches to hard computational problems. They deliver exact answers desired in many applications through symbolic computation and enhance approximate numerical solving,” explained program organizer Greg Blecherman.

Blecherman (Georgia Tech), along with Anton Leykin (Georgia Tech), an IMA postdoctoral fellow at the IMA from 2006 to 2008, and Josephine Yu (Georgia Tech), a long-term visitor in 2007, organized the event and also served as the program’s main lecturers.

The course covered foundational material as well as current applications of algebraic geometry, including Gröbner bases, numerical algebraic geometry, semidefinite programming and real algebraic geometry, and tropical geometry.

Guest lectures were also given by leading researchers in the field, includ-ing Diane Maclagan (University of Warwick), an IMA long-term visitor in 2006; Alicia Dickenstein (University of Buenos Aires), a long-term visitor in 2006 and 2007; Pablo Parrilo (MIT) and Mike Stillman (Cornell University), frequent visitors to the IMA; Bernd Sturmfels (University of California, Berkley), a frequent visitor and a postdoctoral fellow from 1987 to June 1988; Rekha Thomas (University of Washington), a long-term visitor in 2007; and Charles Wampler (General Motors), a long-term visitor from September 2006 to October 2006.


ima at the great minnesota get TogetherOn Sunday, September 4, 2011, the IMA joined the excitement of the Minnesota State Fair. The IMA’s exhibit featured postdocs currently in residence at the institute to share a little about what the IMA does. “Our booth’s theme, ‘Math is the Answer,’ illustrated how we use math to address challenges facing health, the environment, and national security,” IMA director Fadil Santosa explained. The booth featured various kid-friendly math activities, from learning about tsunami prediction to cracking a code using an interactive cryptography activity. A homemade wooden map of Minnesota could also be used to play the infamous Traveling Salesman game. The postdocs and staff had a ton of fun, sharing their stories and meeting friendly faces at the fair.

ima Video archiverecord views reached, improvements coming soon Did you know that the IMA records its talks, workshops, specials semi-nars, and public lectures, and you can watch many of them streaming live online? In fact, the IMA’s video archive is the second most-visited section of the website after program information. The video page received approximately 15,000 page views during the 2011–2012 program year! The IMA’s staff is currently working on improving the video quality and resolution, aiming to make all of the live video high definition as well as more mobile friendly. If you’ve missed a lecture, or want to re-visit one of your favorites, please visit www.ima.umn.edu/videos.

math and science Family Fun FairIn November 2011, the IMA headed to the University of Minnesota College of Science and Engineering’s Math and Science Family Fun Fair. The fair, featuring activities, hands-on exhibits, and entertaining presentations, created a fun atmosphere for kids of all ages. IMA postdoctoral fellows Brendan Ames, Aycil Cesmelioglu, Paolo Codenotti, and Yulia Hristova attended the booth.

The kids really enjoyed the

cryptography activity,” said

hristova. “They were able to

have fun, create a ‘Math is

cool’ message, and learn a little

about this important area of

mathematics at the same time.” —Yulia hRisToVa

University of chicago University of Delaware University of Houston University of illinois at Urbana

champaignUniversity of iowa University of Kentucky University of maryland University of michigan University of minnesota University of North carolina,

greensboroUniversity of Notre Dame University of Pennsylvania University of Pittsburgh University of Tennessee University of Wisconsin-madisonUniversity of Wyoming Wayne state University Worcester Polytechnic institute Zhejiang University

CoRPoRaTions

Boeing corningeaton exxonmobil Ford general motors Honeywell iBm

GoVERnMEnT laBs

lawrence livermore National laboratory

los alamos National laboratory medtronicsandia National laboratoriesschlumberger-Doll researchsiemens

insTiTuTions

arizona state University, Tempe colorado state Universitygeorgia institute of Technology indiana University iowa state University Korea advanced institute of science

and Technology (KaisT) michigan state University michigan Technological University mississippi state University Northern illinois University ohio state University Pennsylvania state University Pohang University of science and

Technology (PosTecH)Portland state UniversityPurdue University rice University rutgers University seoul National University Texas a&m University University of central Florida

Board of Governors

PeTer W. BaTes michigan state University, 2009–2013

reNe carmoNa Princeton University, 2011–2015

DaViD cHocK University of michigan, 2009–2013

amir DemBo stanford University, 2012-2016

BreNDa l. DieTricH iBm, 2008–2012

roBerT gHrisT University of Pennsylvania, 2009–2013

aNNa gilBerT University of michigan, 2007–2011

THomas graNDiNe Boeing, 2012–2016

THomas yiZHao HoU california institute of Technology, 2010–2014

TracHeTTe l. JacKsoN University of michigan, 2012–2016

DiaNe lamBerT google inc., 2008–2012

ricHarD m. mUrray california institute of Technology, 2011–2015

DoUglas W. NycHKa National center for atmospheric research

2011–2015

DaNa raNDall georgia institute of Technology, 2010–2014

DaViD H. sHarP los alamos National laboratory, 2007–2011

PaNagioTis e. soUgaNiDis University of chicago, 2010–2014

VlaDimir sVeraK University of minnesota, 2008–2012

Community Relations Committee

riDgWay scoTT University of chicago

DoNalD KaHN University of minnesota

WillarD miller University of minnesota

JoHN DexHeimer First analysis

roger lUi Worcester Polytechnic institute

locKWooD carlsoN carlson consulting group

William PUlleyBlaNK United states military academy

FaDil saNTosa ima

aNasTacia QUiNN DaVis University of minnesota

iMa Directors and staff

Fadil santosa, Director

Jiaping Wang, Deputy Director

luca capogna, associate Director

chehrzad shakiban, associate Director

Katherine D. cramer, chief of staff

eve marofsky, office supervisor

georgia Kroll, Workshop coordinator

Holly Pinkerton, Housing/Visa coordinator

ines Foss, accounting supervisor

samuel richter, accountant

amanda aranowski, communications coordinator

Kumsup lee, systems manager

Qing cui, Database systems manager

chad sullivan, assistant systems manager

2011-2012 Postdoctoral fellowsBrendan ames

Paolo codenotti

xin liu

shiqian ma

arthur szlam

caroline Uhler

Divyanshu Vats

Teng Zhang

industrial Postdoctoral fellowsgabriela martinez, 2011 Ph.D., stevens institute of Technology

Junshan lin, 2011 Ph.D., michigan state University

Postdoctoral Employment, 2012aycil cesmelioglu, 2010 Ph.D., rice University, oakland University

Jintao cui, 2010 Ph.D., louisiana state University, University of arkansas, little rock

raya Horesh, 2010 Ph.D., emory University, iBm research

yulia Hristova, 2010 Ph.D., Texas a&m University, University of michigan, Dearborn

shiqian ma, 2010 Ph.D., columbia University, city University of Hong Kong

yu (David) mao, 2010 Ph.D., University of california-los angeles, google

Dimitrios mitsotakis, 2007 Ph.D., University of athens, University of california, merced

Weifeng (Frederick) Qiu, 2010 Ph.D., University of Texas-austin, city University of Hong Kong

iMa Partners

The ima is a partnership of the National science Foundation, the University of minnesota, and a broad con-sortium of affiliated universities, government laboratories, and corporations. affiliation brings many benefits to members, including access to research, influence over the ima’s agenda, collaboration within the ima’s network, and opportunities to participate in workshops, short courses, and tutorials.

The institute for mathematics and its applications connects scientists, engineers, and mathematicians in order to address scientific and technological challenges in a collaborative, engaging environment, devel-oping transformative, new mathematics and exploring its applications, while training the next generation of researchers and educators. it receives major funding from the National science Foundation and the University of minnesota.

The University of minnesota is an equal opportunity educator and employer. The University’s mission, carried out on multiple campuses and throughout the state, is threefold: research and discovery, teaching and learning, and outreach and public service.

This publication/material is available in alternative formats upon request. Direct requests to georgia Kroll, workshop coordinator, at [email protected].

© 2013 regents of the University of minnesota. all rights reserved.

Credits Writer/editor: amanda aranowskiDesigner: Dawn mathersPhotography: istock, amanda aranowski


Infinite Dimensional and Stochastic Dynamical Systems

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Workshops

Dynamical Systems in Studies of Partial Differential Equations september 24–28, 2012

Random Dynamical Systems october 22–26, 2012

Lattice and Nonlocal Dynamical Systems and Applications December 3–7, 2012

Theory and Applications of Stochastic PDEs january 14–18, 2013

Stochastic Modeling of the Oceans and Atmosphere March 11–15, 2013

Stochastic Modeling of Biological Processes May 13–17, 2013

orgAnIzIng CoMMItteePeter Bates / Michigan State University

Martin Hairer / Warwick University

Kening Lu / Brigham Young University

Peter Polacik / University of Minnesota

Wenxian Shen / Auburn University

sept 2012 – june 2013

Documents

IMA Institute for Mathematics and its Applications … › ... › files › AnnualReport2012.pdfThe Year in Review Fiscal year July 1, 2011, to June 30, 2012 Program year september