Seminars are held Tuesdays and Thursdays in POB 6.304 from 3:30-5:00 pm, unless otherwise noted. Speakers include scientists, researchers, visiting scholars, potential faculty, and ICES/UT Faculty or staff. Everyone is welcome to attend. Refreshments are served at 3:15 pm.
ICES Seminar-Babuska Forum Series
Friday, Jan 27, 2017 from 10AM to 11AM
by Scott Aaronson
Computer Science, UT Austin
In the near future, there will likely be special-purpose quantum computers with 40-50 high-quality qubits. In this talk, I'll discuss general theoretical foundations for how to use such devices to demonstrate "quantum supremacy": that is, a clear quantum speedup for some task, motivated by the goal of overturning the Extended Church-Turing Thesis (which says that all physical systems can be efficiently simulated by classical computers) as confidently as possible.
Based on recent joint work with Lijie Chen, https://arxiv.org/abs/1612.05903, and earlier joint work with Alex Arkhipov, http://arxiv.org/abs/1011.3245
Dr. Aaronson is David J. Bruton Jr. Centennial Professor of Computer Science and the founding director of UT Austin's new quantum computing center. Prior to joining UT, he was part of the faculty of Electrical Engineering and Computer Science at MIT for nine years. Dr. Aaronson received his BSc in computer science in 2000 from Cornell University with a minor in Mathematics. He then moved to the University of California, Berkeley to pursue his PhD in computer science. His primary area of research is quantum computing and computational complexity theory.
Hosted by Amir Gholaminejad
ICES Seminar-Molecular Biophysics Series
Monday, Jan 30, 2017 from 2PM to 3PM
How Hsp70s move and pull part protein complexes and aggregates
by Rui Sousa
UT Health Science Center, San Antonio
In addition to their roles in protein folding, Hsp70 chaperones function as motors that pull proteins into the ER and mitochondria, and that dissociate protein complexes and aggregates. How these physical transformations are effected has been unclear, but recent theoretical and experimental work indicates that neither a classical Brownian ratchet (in which an Hsp70 asymmetrically captures spontaneous fluctuations in its substrates), nor a power-stroke mechanism (in which a conformational change exerts a directed force coincident with a step in the ATP hydrolysis cycle) explain Hsp70 action. Instead, Hsp70s exhibit an unprecedented mechano-chemical cycle in which co-chaperones load Hsp70s onto the flexible peptide segments of their substrates within structurally constrained spaces, allowing the Hsp70s to dynamically generate pushing and pulling forces against those substrates.
Hosted by Ron Elber
ICES Seminar-Cardiovascular Simulation Series
Friday, Feb 3, 2017 from 2PM to 3PM
Mechanical instability and tortuosity of arteries: theory and applications
by Hai-Chao Han
The University of Texas at San Antonio
The mechanical stability of blood vessels is important for maintaining normal blood flow and vascular function. This talk will summarize our recent work on the buckling of arteries under various loads, including both the theoretical models and experimental results. We propose that mechanical buckling could be a possible mechanism in the development of tortuous blood vessels which is associated with aging, hypertension and degenerative diseases in many patients.
Dr. Han is the Zachry Endowed Chair Professor and Department Chair of Mechanical Engineering at the University of Texas at San Antonio (UTSA). He received his Ph.D. degree in Solid Mechanics/Biomechanics in 1991 from Xi’an Jiaotong University in China with joint training from the University of California at San Diego under the tutelage of Professor YC Fung. Dr. Han was an Associate Professor at Xi’an Jiaotong University and a Research Engineer II at Georgia Institute of Technology before joining UTSA in 2003. Dr. Han’s research interests are in the area of cardiovascular biomechanics with focus on arterial wall mechanical and instability, cardiac mechanics, and tissue remodeling. He has published over 100 peer-reviewed journal papers. He received a CAREER award from NSF in 2007. He is a Fellow of American Heart Association (AHA), College of Fellows of American Institute for Medical and Biological Engineering (AIMBE), and American Society of Mechanical Engineers (ASME). He is an Associate Editor of the ASME Journal of Biomechanical Engineering and the editorial board of a number of journals.
Hosted by Michael Sacks
ICES Seminar - Computational Medicine Series
Friday, Feb 10, 2017 from 2PM to 3PM
Abdominal Aortic Aneurysm Risk Assessment: Biomechanics or Geometry-based Criterion?
by Ender Finol
Associate Professor, Department of Mechanical Engineering, University of Texas at San Antonio
The rupture of an abdominal aortic aneurysm (AAA) is believed to represent the culmination of a complex vascular mechanism partially driven by the forces exerted on the arterial wall. To prevent rupture, a diagnosed AAA is differentiated by its suitability for surgical or endovascular repair based on its maximum diameter or expansion rate measured over time during patient follow-up. At nearly all major hospitals in the U.S., subjects with aneurysms smaller than 5.5 cm (on average) are placed under clinical surveillance while those greater or equal than 5.5 cm or growing at a rate 3 0.5 cm/year are recommended for elective repair. Since AAA is a largely asymptomatic condition, the screening necessary to measure growth rate over time often cannot be completed. It is a known fact, however, that basing the clinical management of this disease on expansion rate and/or maximum diameter is not a reliable measure of individual rupture risk. This is evident by the number of small aneurysms that rupture prior to reaching the critical diameter of 5.5 cm and the many more that are diagnosed at an advanced stage of expansion having exceeded the threshold size for intervention and yet did not rupture. This inability to predict accurately the individual at-risk status of an AAA has led to extensive research into other potential indicators of rupture or equivalent evaluation criteria for assessing the need for repair. Our laboratory is using a combination of image processing and numerical methods to model the geometry and the biomechanical environment of patient-specific AAAs. In this talk, I will describe our efforts in accurately modeling these aneurysms at the organ and tissue scales and the useful quantitative information we can predict from clinical images. This research represents a contribution to the ultimate goal of developing a computational tool that can be used in a clinical setting to assess the individual aneurysm rupture potential on the same day of AAA diagnosis.
Dr. Finol received his B.E. degree in Mechanical Engineering from Universidad de Carabobo, Venezuela (1994), M.S. degree in Mechanical Engineering from University of Massachusetts Lowell (1997) and Ph.D. degree with a dual major in Mechanical and Biomedical Engineering (2002) from Carnegie Mellon University. He is currently an Associate Professor in the Department of Mechanical Engineering at University of Texas at San Antonio and previously a research faculty at Carnegie Mellon Universitys Institute for Complex Engineered Systems (ICES). Dr. Finol operates the Vascular Biomechanics and Biofluids Laboratory and has research interests that include non-destructive tissue mechanics, fluid and solid mechanics modeling of blood vessels, design and optimization of intravascular medical devices, and medical image analysis.
Hosted by Michael Sacks
Tuesday, Mar 28, 2017 from 3:30PM to 5PM
Analysis of the DG method applied to an elliptic problem with nonlinear Newton boundary conditions
by Miloslav Feistauer
Professor, Charles University, Faculty of Mathematics and Physics Prague, Czech Republic
The lecture will be devoted to the analysis of the discontinuous Galerkin method (DGM) for the numerical solution of an elliptic boundary value problem with a nonlinear Newton boundary condition in a two-dimensional polygonal domain. Problems of this type appear in the modeling of electrolysis of aluminium, radiation heat transfer problems or in nonlinear elasticity. Using the monotone operator theory, it is possible to prove the existence and uniqueness of the exact weak solution and the approximate DG solution. The main attention is paid to the study of error estimates. To this end, the regularity of the weak solution is investigated and it is shown that due to the singular boundary points, the solution looses regularity in a vicinity of these points. It comes out that the error estimation depends essentially on the opening angle of the corner points and the nonlinearity in the boundary term. It also depends on the parameter defining the nonlinear behaviour of the Newton boundary condition. Important tools in the analysis are the results of A. Buffa and C. Ortner on compact embeddings of broken Sobolev spaces. Theoretical results are accompanied by numerical experiments showing nonstandard behaviour of the error in the L2-norm and the H1-seminorm.
The results were obtained in cooperation with Filip Roskovec and Anna-Margarete Sandig.
Prof. Dr. Miloslav Feistauer, DrSc., Dr.h.c., professor of mathematics at Charles University in Prague, was born in Náchod into a family of teachers. From an early age he was interested in mathematics and physics, and also devoted himself to music. After eleven years at high school in 1960, wondering whether to study violin or mathematics, he decided to study at the Faculty of Mathematics and Physics, Charles University. There he has spent all his professional life. After graduating in Applied Mathematics in 1965, he joined the Department of Applied Mathematics. After three years he was appointed lecturer and in the following year received the degree of Doctor of Natural Sciences (RNDr.). In 1972 he defended the scientific degree of Candidate of Sciences (Ph.D.) and in 1982 took a habilitation in mathematics. However, since Prof. Feistauer had From Pokroky Mat. Fyz. Astronom. 58 (2013), 73–75. Translated by Miluša Bubeníková 489 never been politically active, his appointment to the position of associate professor was held up till 1988. In 1990 he was awarded the degree of Doctor of Sciences (DrSc.) and shortly thereafter in 1991 was appointed full professor of mathematics in the field of approximate and numerical methods. In this position he has worked up to now. In the period of 1986–1994 he worked at the Mathematical Institute of Charles University and in 1994 he gained the post of the head of the Department of Numerical Mathematics at Charles University in open competition. In this position he served till 2006. Professionally, Prof. Feistauer's scientific activity has been in the areas of partial differential equations, numerical and computational mathematics and mathematical methods in fluid dynamics. More than 200 papers, 3 monographs, more than 130 invited lectures at universities, more than 180 lectures at conferences (including 68 invited main or plenary lectures and 15 lectures in Oberwolfach), organizing conferences in the Czech Republic and abroad (e.g., member of the Program Committee of the series of the conferences ENUMATH). Teaching activities of Prof. Feistauer are in accord with his successful research activities. In addition to courses on numerical mathematics he presents lectures on mathematical methods in fluid mechanics and mathematical modelling and supervises seminars on continuum mechanics and numerical mathematics. He has significantly contributed to the development of numerical analysis and mathematical modelling at the Faculty of Mathematics and Physics. His lectures are highly evaluated by students. He has trained a number of graduate and doctoral students who were awarded in various national and international competitions. Many of his former students became prominent experts, associate professors and full professors at universities in the Czech Republic and abroad where they continue his work and fulfil his aims and objectives. In the years 1994–2012 Prof. Feistauer was member of the Scientific Council of the Faculty of Mathematics and Physics. He has worked in various committees and bodies of the faculty, but also beyond. He is member of the committee for doctoral studies F11 and M6 at Charles University, he was member of the Scientific Council of the Faculty of Mechanical Engineering, currently he is member of the Scientific Council of the Faculty of Chemical Engineering at the Institute of Chemistry and Technology in Prague and for many years he worked in an advisory commission of the Grant Agency of the Czech Republic. He is member of numerous scientific
societies (GAMM, ISIM, AMS, EUROMECH, ECMI and others) and member of the editorial boards of five international journals. His research and teaching activities were awarded by the medal of the Faculty of Mathematics and Physics and by the silver medal of Charles University. In 2004 he was elected member of the Learned Society of the Czech Republic. In 2006, Prof. Feistauer received another prestigious award, the title of Honorary Doctor of the Technical University of Dresden. Among his more recent awards, Feistauer received the 2008 Memorial Medal of the Charles University and the 2013 Memorial Medal of the Czech Mathematical Society. His nonprofessional interests include the history of art, music: painting, playing violin, viola, and music composition.
Hosted by Ivo Babuska
Tuesday, Apr 11, 2017 from 3:30PM to 5PM
by Ioannis Kevrekidis
Hosted by Greg Rodin