Browse Issues:

### New Mathematics for Extreme-scale Computational Science?

Let’s start with the good news: Mathematics continues to be the most important contributor to any work in large-scale computational science. This is so because computational complexity becomes ever more important with faster computers. Once systems are large enough, the best algorithms will always be the ones with the best asymptotic complexity. High-quality journals, such as the SIAM Journals on Numerical Analysis and Scientific Computing, regularly publish papers in this area that advance the research frontier.

### Obituaries

Michael James David Powell, who passed away on April 19, was one of the giants who established numerical analysis as a major discipline and created its current intellectual landscape. From his life work  have emerged both mathematical foundations and practical algorithms of nonlinear optimization, as well as decisive contributions to approximation theory.

### On Markov Decision Processes

Sequential planning under uncertainty is a basic optimization problem that arises in many different settings, ranging from artificial intelligence to operations research. In a generic system, we have an agent who chooses among different actions and then receives a reward, after which the system moves on in a stochastic way. Usually the aim is to maximize the expected (discounted) reward of the system over a finite or, in certain cases, as described below, an infinite time horizon.

### A Minimalist Minimizes an Integral

In this issue we present a solution that is shorter than Johann Bernoulli’s famous optics-based idea of minimizing
 $\tag{1} \int_{\gamma OA}F(y)ds$

over smooth curves connecting two given points $$A$$ and $$B$$; here $$F(y) > 0$$ is a given function and $$ds$$ is an element of arc length. Bernoulli based his beautiful solution on the equivalence between Fermat’s principle and Snell’s law.

### The Moody’s Mega Math Challenge Marks 10th Year

Can you recall the first time you worked with a team on a significant mathematical modeling problem? For me, it was as a senior at Oberlin College, in a project for NASA in an operations research course taught by Professor Bruce Pollack-Johnson (now at Villanova). I am certain that the experience played a large role in my decision to become an applied mathematician and to join the faculty at Harvey Mudd College, which provides industrial mathematical modeling experiences through its senior capstone clinic projects. SIAM provides students with mathematical modeling experiences through the Moody’s Mega Math (M3) Challenge, which, like COMAP’s Hi-MCM, makes the experience of team-based modeling available to U.S. high school students. M3 is entirely Internet-based, and carries no entry or participation fees.

### U.S. National Academies Elect New Members

Among the most important honors accorded to scientists and engineers in the U.S. is election to the National Academies of Engineering and Sciences. The National Academies were created (NAS in 1863 by President Abraham Lincoln; NAE in 1964) to advise the federal government in matters of science and technology. At their annual meetings, each announces the names of newly elected members. Distinguished members of the SIAM community appear regularly on both lists, and 2015 is no exception.

### European Students Gather at TU Delft for Krylov Day

On February 2, the SIAM Student Chapter at TU Delft held a one-day workshop on Krylov subspace methods. The speakers, 12 PhD students in numerical linear algebra, gave overviews of their current work and its relation to Krylov subspaces. Participants came from different universities in The Netherlands and other European countries; among them were representatives of SIAM Student Chapters at Magdeburg, Manchester, and Prague.

### Numerical Notation Systems as Cultural Artifacts

BOOK REVIEW: Numerical Notation: A Comparative History. By Stephen Chrisomalis, Cambridge University Press, New York, 2010, 496 pages, \$114.99.

### AAAS & the SIAM Community

This year’s SIAM Conference on CSE featured a new attraction: “SIAM Communication Doctors,” a booth for people wishing to craft effective messages about their research—for communication to future employers, at outreach events, or for the press. Graduate students, postdocs, and faculty visited the booth, hoping that booth doctors could turn their research summaries into good stories that would appeal to the public. At the booth, reporter Flora Lichtman, whose work has appeared in The New York Times and on NPR’s Science Friday, joined conference attendees Nick Higham (University of Manchester), Jeff Humpherys (Brigham Young University), Rachel Levy (Harvey Mudd College), and Matt Parno (Massachusetts Institute of Technology) to offer feedback as people pitched their ideas.

## SIAM Connect

 Tristan van Leeuwen receives SIAM Activity Group on Geosciences Junior Scientist Prize SIAM joins call to action for American Innovation Imperative Mathematical models with complicated dynamics for disease study

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## Professional Opportunities

 Accenture Analytics - Global Management - Data Scientist Analyst+ - Accenture - New York, NY Staff Scientist I - Speech Recognition, NLP and Multimedia - New MS Grad - Raytheon - Cambridge, MA Microsoft: Data Scientists - Microsoft: Data Scientists - Redmond, WA

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## Conferences & Events

July 08, 2015 To July 10, 2015

SIAM Conference on Control and Its Applications (CT15)

July 06, 2015 To July 10, 2015

ICERM IdeaLab: Inverse Problems and Uncertainty Quantification

July 07, 2015 To July 23, 2015

Graduate Summer School: Games and Contracts for Cyber-Physical Security

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## Inside SIAM

#### Upcoming SIAM Events

July 08, 2015 To July 10, 2015

SIAM Conference on Control and Its Applications (CT15)

August 03, 2015 To August 07, 2015

SIAM Conference on Applied Algebraic Geometry (AG15)

August 10, 2015 To August 14, 2015

8th International Congress on Industrial and Applied Mathematics (ICIAM 2015)

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