The CMD 2012 Program is a showcase of research in computational mathematics at SFU, UBC, and UVic.

Program Schedule

Date: Wednesday, August 8th, 2012 Location: IRMACS Centre, Simon Fraser University 

Influence in Social Networks.

Benjamin Lundell, University of Washington

The behavior of members of a social network has been studied for many years. The traditional approach has been to look at the aggregate behavior of the network, and then average this aggregate over the network's users to determine a "representative member" of the network. In particular, this method assumes that each member acts independently of his or her peers and ignores the influence one member might have on another. In the last ten years, computer scientists and physicists have developed new approaches to studying this problem which are based on the assumption that a members' peers greatly influence his or her behavior. Thus, these models raise the question, "Who are the most influential members of a social network?" In this talk, I'll discuss some ideas on how to answer this question, and share some results of an ongoing project about political influence in the United States. This is joint work with Chris Aholt.

Towards generating random mammalian genomes.

Marni Mishna, Simon Fraser University

Genome arrangements, a major mechanism of evolution, shuffle genetic material along chromosomes. Thus, a now standard approach models groups of close genomes as signed permutations. The correct data structure to study permutations in this context is the common interval tree. In this talk we will describe the process of considering tree parameters to refine the class of common interval trees (hence permutations) to those that represent mammalian genomes well. These refinements are particularly amenable to Boltzmann random generation and analytic enumerative techniques. Work in collaboration with Mathilde Bouvel, Cedric Chauve, Rosemary McCloskey, Cyril Nicaud and Carine Pivoteau.

Formal Identification of DC Operating Points in Integrated Circuits and some Lessons in (Ir)Reproducible Research in Computational Math

Ian Mitchell, University of British Columbia

A DC operating point is an equilibrium toward which a circuit will be drawn for sufficiently nearby initial conditions when any inputs are held fixed.  DC operating points may or may not be desirable features in a circuit -- in an oscillator they represent lockup, but in a memory element they are the mechanism whereby discrete state is
stored.  Consequently, it is useful to identify a circuit's DC operating points.  Because the circuit is naturally drawn towards them, the most common technique to identifying such equilibria is through simulation; however, it is quite possible for the domain of attraction of an equilibrium to be small enough that simulation is unlikely to find it, yet large enough to cause occasional problems.

In joint work with Mohamed Zaki & Mark Greenstreet, we strung together a collection of public software from the formal verification and numerical analysis communities to rigourously identify and classify all potential DC operating points for surprisingly complex circuit models.  Unfortunately, the resulting workflow has proved fragile, and significant effort would be required for reproduction and/or extension.  In the second half of the talk I will discuss some tools and techniques that would have significantly improved the reproducibility of the results had they been adopted.

Venn diagrams and tatami tilings: vignettes from computational mathematics.

Frank Ruskey, University of Victoria

In this talk I will explain how computation has helped me and my students in resolving certain mathematical questions, via two specific recent examples. In the first example, we consider the problem of constructing a simple rotationally symmetric 11-Venn diagram. This problem was open for about 40 years and several incorrect solutions were proposed. Initially the problem seemed to be beyond the reach of exhaustive searches, but our recognition of a new type of "near-symmetry" in Venn diagrams suggested that searching in a certain reduced solution space might be fruitful --- which indeed it was. In the second example, we consider a tiling problem first investigated by Don Knuth. On the basis of his computations it seemed that the generating function for counting those tilings was I(z)*S(z) where I(z) was a mysterious irreducible polynomial and S(z) was a well structured and predictable. We have proved that S(z) is what it seemed to be, and revealed many interesting properties of the irreducible I(z), but its exact expression is still not known. [The students mentioned above are Khalegh Mamakani and Alejandro Erickson.]

Spectral Analysis and Dynamical Behavior of Complex Networks.

Ljiljana Trajkovic, Simon Fraser University

Discovering properties of the Internet topology is important for evaluating performance of various network protocols and applications. The discovery of power-laws and the application of spectral analysis to the Internet topology data indicate a complex behavior of the underlying network infrastructure that carries a variety of the Internet applications. In this talk, we present analysis of datasets collected from the Route Views and RIPE projects. The analysis of collected data shows certain historical trends in the development of the Internet topology. While values of various power-laws exponents have not substantially changed over the recent years, spectral analysis of matrices associated with Internet graphs reveals notable changes in the clustering of Autonomous Systems and their connectivity.

Poster Information

The SFU Mathematics Department invites undergraduate and graduate research students, postdoctoral fellows and faculty members to participate in the Computational Math Day 2012 Poster Session.

The only requirement is that the poster has mathematics in it. It may be applied, pure, computational or experimental mathematics. If you have already prepared a poster for a presentation at another scientific meeting this year, and you would like to present it to members of the Department, this is an appropriate venue. If you wish to present a computer demo this is also possible.

Prizes

There will be one prize of $200 (winner) and one prize of $100 (runner-up) for the best undergraduate poster, and one prize of $200 (winner) and one prize of $100 (runner-up) for the best graduate poster. Judging will be based on both content and presentation.

Submission Details

Poster titles must be submitted via the online registration form by August 2nd, 2012. Presenters are responsible for printing their own poster.

Display Details

The posters will be displayed in the IRMACS atrium. Poster presenters can set up their posters as early as 9:00am on August 8th, 2012. The poster and demo session will take place from 11:15am to 1:15pm. Awards will be made at 4:30pm, followed by a presentation of the winning undergraduate and winning graduate poster.

Details

• Registration is required by July 31st, 2012, for catering purposes. A registration fee of $30 per participant will be charged to all participants except invited speakers and invited guests. The registration fee includes the cost of a buffet lunch at IRMACS.
• Students may wish to ask their supervisor to pay for their registration fee.
• The registration fee may be paid by cash or cheque at the registration desk on the day of CMD 2012 (receipt will be provided at registration) or through an SFU account (journal voucher).
• Participants who need assistance with the payment should contact Paul Tupper. 

Thank you to our Sponsors

	Maplesoft, a subsidiary of Cybernet Systems Co. Ltd. in Japan, is the leading provider of high-performance software tools for engineering, science, and mathematics. Its product suite reflects the philosophy that given great tools, people can do great things. Maplesoft’s core technologies include the world’s most advanced symbolic computation engine and revolutionary physical modeling techniques. Combined together, these technologies enable the creation of cutting-edge tools for design, modeling, and high-performance simulation.
	The IRMACS Centre is a unique, interdisciplinary research facility that enables collaborative interaction - intellectually, physically and virtually. IRMACS focuses on facilitating the human interactions that are critical in interdisciplinary research by providing the technologies and technical support to promote effective interactions (computational, networking, human-computer interaction, remote collaboration, and visualization). By removing the traditional boundaries between scientific disciplines and physical boundaries due to distance, IRMACS creates a synergistic environment on an international scale.
	PIMS promotes research in and applications of the mathematical sciences, facilitates the training of highly qualified personnel, enriches public awareness of and education in the mathematical sciences, and creates mathematical partnerships with similar organizations in other countries.
	Motivated by the expanding role of scientific computation and mathematical modeling in science and engineering, the Centre for Scientific Computing was formed to bring together interdisciplinary research teams from various Simon Fraser University faculties. The major purpose of the Centre is to provide Simon Fraser University with a visible focus for computational research both on campus and in the wider Pacific Rim research community. Specifically, the Centre's goals are to facilitate discussion between scientific computing research groups (through seminars, workshops, conferences) to provide advanced instruction in computational techniques and applications (through graduate and post-doctoral programs), and to actively pursue joint research ventures with industry, government and laboratories.
	The Department of Mathematics currently numbers 39 faculty. In a typical semester the ranks of regular faculty are augmented with up to 20 post-doctoral fellows and Visiting Professors. At present the Department has a graduate enrolment around 80. The Department has earned a national and international reputation as one of the most forward-looking and broad-based mathematical sciences departments in Canada. Undergraduate and graduate students thrive in the highly interactive and personalized environment which characterizes the Department and is typical of the unique character of Simon Fraser University. We offer a broad program of training in contemporary Mathematics, but also specialize in various areas for which we are internationally recognized.

View photos from this event.