Valeria Simoncini talks about Model-Assisted Effective Large Scale Matrix Computations (Photo credit: Nick Higham)

Valeria Simoncini of Universita’ di Bologna, Italy, gave an account of recent advances in the solution of large scale matrices. Many advanced mathematical models require the solution of large algebraic linear systems, making these models computationally effective. Dr. Simoncini described several state-of-the-art iterative linear system solvers in an invited talk titled Model-Assisted Effective Large Scale Matrix Computations. Examples included matrices and vectors which inherit spectral properties of underlying continuous operators.

Claude LeBris of the CERMICS Research unit at Ecole Nationale des Ponts et Chaussées in France gave an invited lecture on Multiscale Problems Involving Disorder: A Mathematical Perspective. He described modeling and numerical approaches to study materials that are seen as small random perturbations of periodic materials The theoretical concepts are designed to make the mechanics of non-periodic materials more practical, keeping the computational workload minimal despite the presence of disorder.

In his Past President’s Address, SIAM Past President Douglas Arnold of the University of Minnesota began by recounting the progress SIAM has made in increased membership numbers, new projects and publications, and geographical reach. “The ‘A’ in SIAM does not stand for American,” he said going on to describe SIAM’s international growth over the past few years, specifically its recent reach in China.

Doug Arnold thanking other SIAM officers from his tenure as President (Photo credit: Nick Higham)

He then took the opportunity to address a very timely and relevant issue: problems facing scholarly publishing.

“Math literature is enduring,” he said, noting that citations in mathematical journals often go back decades, and emphasizing the need for mathematicians to take a stance on this important issue. “Refereeing is super-important in math because we believe in the truth.” He explained a few cases of plagiarism that should be very worrisome to the community, reinforcing the importance of tools like CrossCheck employed by SIAM Journals. He then turned his focus on impact factors and their skewed nature due to self-citations and self-references. Illustrating how impact factors can be greatly influenced by self-citations with a series of convincing graphs, he cautioned the audience to be more guarded about the authenticity of bibliometrics.

The final part of Dr. Arnold’s talk focused on his personal views on the influence of large commercial publishers and one in particular–Elsevier–which, in his opinion is affecting the publishing world with its non-competitive prices, journal bundling, and huge profit margins, all the while relying on unpaid volunteer labor. Lastly, he mentioned the need to redefine copyright laws in general, transferring more rights to authors and less to publishers. In a very engaging lecture, Dr. Arnold inspired a lot of food for thought about the future of mathematical publishing.

Robert Bridson delivering the I. E. Block Lecture: Creating Reality: The Mathematics Behind Visual Effects

The 2012 W. T. and Idalia Reid Prize Lecture was awarded to Ruth Curtain of the University of Groningen in the Netherlands. She delivered her prize lecture, Algebraic Properties of Riccati Equations yesterday afternoon, in which she described algebraic properties of Riccati equations whose results have direct applications to spatially distributed and invariant systems. Dr. Curtain elucidated on positive results for both commutative and noncommutative algebras. She described recent results of  algebraic properties of the LQR Riccati equation, explaining that similar techniques can be used to obtain algebraic properties of other Riccati equations.

In the I.E. Block Community Lecture held last evening, Dr. Robert Bridson of the University of British Columbia gave the audience a highly engaging,  behind-the-scenes look at the mathematics that underlies movie special effects.

Dr. Robert Bridson concluding his talk on Creating Reality: the mathematics behind visual effects. "We need more math!"

Using examples of fluid flow, cloth animation, smoke and fire, he illustrated the existence of math-based special effects in movies ranging from blockbusters like Avatar to more obscure productions such as Inkheart. Dr. Bridson broke down the simulation of water using basic schematics. Since fluids like water are amorphous and can take any shape, and simulating each molecule would be computationally intensive, they are usually discretized into blobs or particles, he explained. Following this, various physical parameters are introduced into the simulation, such as gravity, other forces, interaction among molecules, and so on. The physical equation would also take into account the fact that water is incompressible with the density remaining the same, thus equating the inflow to the outflow.

He thus illustrated how the use of math and physics in virtual effects allows natural motion to just emerge from equations. Physics-based animation gets behind the fundamental math of the phenomenon, hence a lot of numerical methods are involved.

If the gasps and claps were any indication, mathematicians, researchers, and the general public alike greatly enjoyed the presentation. A mathematician who has studied visual effects and 3-D animations for years, Dr. Bridson is co-creator of Naiad, a software that provides liquid and gas simulations to movie studios worldwide, redefining the industry standard for fluid simulations. Free and open to the public, the event no doubt achieved its goal of inspiring public appreciation for math and its influence on the world around us.

Tweets of the day:

nhigham Jul 11, 8:11pm via HootSuite

Robert Bridson – we can’t yet efficiently simulate the foam in the fountain outside the hotel. #SIAMAN12 ow.ly/i/LmeU

michiexile Jul 11, 7:43pm via web

Good news: #VFX is not Civil Engineering — noone will die if they screw up the numerics! #SIAMAN12

michiexile Jul 11, 7:26pm via web

Recommended #VFX watching: vimeo.com/9078364 vimeo.com/9076775 #SIAMAN12

What to look for on Thursday:

Student Day Events:

SIAM Book Giveaway – Exhibit Hall STUDENTS ONLY: 4:00-4:30 p.m.

Invited Presentations and Special Lectures

8:30 AM – 9:15 AM

IC7 Freeform Architecture and Discrete Differential Geometry

Helmut Pottmann, King Abdullah University of Science and Technology, Saudi Arabia

Nicollet ABC – Level 1

8:30 AM – 9:15 AM

IC8 Computing Essentials: What SIAM Members Should Know About Emerging Architectures

Michael A. Heroux, Sandia National Laboratories, USA

Nicollet D2/3 – Level 1

9:15 AM – 10:00 AM

IP1 On Mean Field Games

Pierre-Louis Lions, Collège de France, France

Nicollet ABC – Level 1

2:00 PM – 2:45 PM

IP2 Complex Adaptive Systems and the Challenge of Sustainability

Simon Levin, Princeton University, USA

Nicollet ABC – Level 1

2:45 PM – 3:30 PM

IP3 The Isoperimetric Problem Revisited: Exposing Euler’s 1744 Proof of Necessity as a Proof of Sufficiency, as Such the First and Shortest in History

Richard A. Tapia, Rice University, USA

Nicollet ABC – Level 1

Special Events:

6:15 PM – 9:15 PM

Professional Development Evening

Nicollet ABC – Level 1