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Welcome to the Department of Mathematics

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Event: 56th annual meeting of the Canadian Operational Research Society (CORS) in Ottawa.

As in the past two years, we encouraged the undergraduates in Math 402W Operations Research Clinic to submit their projects to the CORS undergraduate student paper competition.  And, once again, they won both prizes.  This year, all 3 projects submitted were chosen as finalists, and presented their work at the meeting. (The fourth finalist was from the University of Alberta; nine entries were received.)  Congratulations go to:

Winners:
Kishley Bhalla, Craig Mathews, W. Brett Robinson and Katie Sclater "Selecting Optimal Tolling Levels: A Case Study for the Fraser River in the Greater Vancouver Area"

Honourable Mention:
Nicole Mo, Alborz Namazi, Joyce Tai and Eric Yuen "Optimal Locations of Telecommunication Equipment: A Case Study for the City of Richmond, British Columbia, Canada"

Finalists:
Kingsley Cheang, Feiqi He, Sarah Lin and Ashlie Neufelt "The Community Mailbox Location-Routing Problem"

Additionally, Second Prize in the CORS Practice Competition went to Daniel Karapetyan (SFU Math postdoc 2011-13) and Abraham Punnen, for their paper "Operational Research Models and Algorithms for Fleet Size Planning and Schedule Optimisation for the British Columbia Ferry Services Inc."  Finalists for the practice competition included teams from the University of Toronto and IBM, first prize went to UOIT.

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Daily News

Upcoming Events

  • Jeffrey Wiens, Ph.D. Thesis Defence, Mathematics Room: K9509 **TIME CHANGED TO 9:30 am
    9:30 AM - 11:30 AM
    August 1, 2014
    (Sr. Supervisor: John Stockie) Title: An efficient parallel immersed boundary algorithm, with application to the suspension of flexible fibers Abstract: We design an efficient algorithm for studying problems in fluid-structure interaction on distributed-memory computer clusters using the standard and generalized immersed boundary (IB) equations. The algorithm utilizes a pseudo-compressibility method recently proposed by Guermond and Minev that uses a directional splitting strategy to discretize the incompressible Navier-Stokes equations, thereby reducing the linear systems to a series of one-dimensional tridiagonal systems. This endows our algorithm with the computational complexity of a completely explicit method and excellent parallel scaling properties. We demonstrate the effectiveness of our IB algorithm through detailed numerical and performance studies. For several model problems, we report the accuracy and convergence rates of our algorithm in two and three dimensions. These results are then compared with alternate projection-based IB algorithms. The execution time and scaling properties of our algorithm are then investigated and we discuss the performance benefits over alternative approaches. We conclude with an investigation of the dynamics of flexible fibers in a shear flow using the generalized IB method. In our simulations, we reproduce the orbit classes observed experimentally by Mason and co-workers. Lastly, using parallel tiling techniques, we simulate dilute suspensions that contain as many as 256 fibers.
  • Symposium on Mathematics and Computation
    9:00 AM - 4:30 PM
    August 6, 2014
    Invited Speakers Ben Adcock (Mathema(cs, SFU) Andrew King (D-Wave Systems, Burnaby) 1 Greg Mori (Computer Science, SFU) Chris Sinclair (Mathema(cs, Oregon)
 Stephanie van Willigenburg (Mathema(cs, UBC)
  • Colin Exley, M.Sc. Thesis Defence, Mathematics Room: PIMS 8500 TASC II
    10:00 AM - 12:00 PM
    August 6, 2014
    (Sr. Supervisor: JF Williams) Title: An Agent-Based Approach to Modelling Chronic Offenders Abstract: Police departments are required to ensure the safety of the general population using limited resources. Chronic offenders are a major drain on police resources. The precise definition of a chronic offender may change between jurisdictions but the general concept is a class of offenders who commit many crimes in short intervals. Unlike other offenders who typically stop committing crimes early in life, chronic offenders continue committing crimes late in life. Understanding this class of offenders allows police departments to modify their operational strategies and make better use of their limited resources. We develop an agent-based model of how chronic offenders move between incarceration and freedom. Under appropriate limits we convert the agent-based model to a system of differential equations which can be analyzed using established differential equation methods.
  • Clinton Innes, M.Sc. Thesis Defence, Mathematics Room: PIMS 8500 TASC II
    10:30 AM - 12:30 PM
    August 7, 2014
    (Sr. Supervisor: Razvan Fetecau) Title: Quantifying the effect of open-mindedness on opinion dynamics and advertising optimization Abstract: Group opinion dynamics shape our world in innumerable ways. Societal aspects ranging from the political parties we support to the economic decisions we make in our daily lives are all directly affected in some way by group opinion dynamics. This makes understanding and potentially being able to predict the complex inter-relationships between individuals’ opinions and group opinion dynamics invaluable both scientifically and economically. We propose an aggregation model incorporating in group out group dynamics, as well as media influence, to establish potential causal relationships between various types of social interaction and social phenomena such as the occurrence of group consensus and the hostile media effect. We further apply our model to simplified comercial applications relating to advertisement optimization to determine the optimal proportion of a population to target with advertising in order to maximize opinion shift while fixing cost.
  • Ryan McMahon, M.Sc. Thesis Defence, Mathematics Room: K9509
    10:00 AM - 12:00 PM
    August 11, 2014
    (Sr. Supervisor: Nils Bruin) Title: Solvability of ternary equations of signature (3,3,2) Abstract: In this thesis we examine the primitive solvability of Diophantine equations of the form ax^3 + by^3 = cz^2. For square-free a,b,c, we identify various criteria necessary for the existence of primitive solutions, including a sufficient one. We also present a relatively efficient algorithm to determine whether this criterion is satisfied. Using the algorithm, we compute some data on the relative distribution of the occurrence of various obstructions to the existence of primitive solutions.
  • Avinash Kulkarni, M.Sc. Thesis Defence, Mathematics Room: K9509
    10:00 AM - 12:00 PM
    August 12, 2014
    (Sr. Supervisor: Nils Bruin) Title: On Jacobians of dimension 2g that decompose into Jacobians of dimension g. Abstract: In this thesis we describe a family of Jacobian varieties of non-hyperelliptic genus 2g curves that are isogenous to a product of Jacobians of genus g curves in a specific way. For any hyperelliptic genus g curve C we construct a 2-parameter family of hyperelliptic genus g curves H with J(H)[2] isomorphic to J(C)[2], and a generically non-hyperelliptic curve A such that there is an isogeny from J(C) x J(H) to J(A) whose kernel is the graph of the isomorphism taking J(H)[2] to J(C)[2]. This is accomplished by first showing C can be considered as a subcover of a Galois cover of a P^1 that has A and H naturally arising as subcovers and then showing the naturally occurring isogeny relations have the desired kernel. We also list some corollaries to the main result and provide a magma script to generate non-hyperelliptic genus 4 curves that have curious automorphism groups.
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