Scientific General Events

  • Number theory was coined the "Queen of Mathematics" by Gauss. It is one of the oldest branches of mathematics. Over the years, it has extended its roots into a variety of other domains such as probability, combinatorics, analysis, algebra, and geometry. We hope that this one day conference will give a glimpse into the
    diverse aspects of modern number theory.

     

  • Dr. Igor Burstyn.
    Occupational Medicine, University of Alberta.
    Title: A vignette from occupational epidemiology: Stitching evidence from tattered fabric

    Dr. Mahyar Etminan.
    Centre for Clinical Epidemiology & Evaluation, Vancouver.
    Title: TBA

    Dr. Adrian Levy. Centre for Health Evaluation and Outcome Sciences;
    Department of Health Care and Epidemiology, UBC.
    Title: TBA

    Dr. Bill Leslie.
    Department of Internal Medicine, University of Manitoba.
    Title: TBA

    Dr. Malcolm Maclure.
    Pharmaceutical Services Division, BC Ministry of Health.
    Title: You randomize. We Analyze.

    Dr.Ed Mills.
    Faculty of Health Sciences, SFU.
    Title: TBA

    Dr. Carl Phillips.
    Department of Public Health Sciences, University of Alberta.
    Title: Can quantitative methods help detect and reduce "publication bias in situ"?

    Dr. Jat Sandhu.
    Vancouver Coastal Health.
    Title: TBA

     

     

  • The Mahler measure of curves and surfaces
    by Marie José Bertin Université Pierre et Marie Curie (Paris 6), Institut de Mathématiques de Jussieu

    I report on some new examples of explicit logarithmic Mahler measures of multivariate polynomials.
    When the polynomial defines a parametrizable curve, its Mahler measure is expressed in terms of Bloch-Wigner dilogarithms of an element of the Bloch group of an imaginary quadratic field ( Thus a link with hyperbolic varieties). When the polynomial defines a singular K3-surface, I give several examples of the Mahler measure expressed in terms of the L-series of the K3-surface for s=3. Dedekind zeta motives for totally real fields by Francis Brown CNRS, Institut de Mathématiques de Jussieu, IHES

    On singular Bott-Chern classes
    by José Ignacio Burgos Gil Universidad de Barcelona

    The singular Bott-Chern classes measure the failure of an exact Riemann-Roch theorem for closed immersions at the level of currents. They are the key ingredient in the definition of direct images of hermitian vector bundles under closed immersions and in the proof of the arithmetic Riemann-Roch theorem in Arakelov geometry for closed immersions. There are two definitions of singular Bott-Chern classes. The first due to Bismut, Gillet and Soulé uses the formalism of super connections. The second, due to Zha, is an adaptation of the original definition of Bott-Chern classes by Bott and Chern.In this talk we will give an axiomatic characterization of singular Bott-Chern classes, which is similar to the characterization of Bott-Chern forms, but that depends on the choice of an arbitrary characteristic class. This characterization allow us to give a new definition of singular Bott-Chern forms by means of the deformation to the normal cone technique and to compare the previous definitions of singular Bott-Chern forms. Moreover we will give an explicit computation of the characteristic class associated to Bismut-Gillet-Soulé definition of singular Bott Chern currents.

    Generic p-rank of semi-stable fibration
    by Junmyeong Jang Purdue University

    In this presentation, I will be concerned with two pathological phenomenons of positive characteristic, the failure of Miyaoka-yau inequality and the failure of semi-positivity theorem. Szpiro showed that a Frobenius base change of non-isotrivial smooth fibration violates Miyaoka-Yau inequality. For such a fibration, if the p-rank of the generic fiber is maximal, the dimension of the Lie algebra of Picard scheme is stable after the Frobenius base change. Using this fact and a reduction argument we can construct a counter example of Miyaoka-Yau inequality with smooth Picard scheme, which is a counterexample of Parshin's expectation. And we will see for a semi-stable fibration p : X ? C of a proper smooth surface to a proper smooth curve, if the p-rank of the generic fiber is maximal, the semi-positivity theorem holds and if the p-rank of the generic fiber is 0, some Frobenius base change of p violates the semi-positivity theorem. This result may be applied to a problem of the distribution of p-ranks of reductions of a certain non-closed point in the moduli space of curves over Q¯.

    The Abel-Jacobi map on the Einsestein symbol
    by Matthew Kerr Durham University

    In this talk we consider two different constructions of motivic cohomology classes on families of toric hypersurfaces and on Kuga varieties. Under certain modularity conditions on the former we say how the constructions "coincide", obtaining a complete explanation of the phenomenon observed by Villegas, Stienstra, and Bertin in the context of Mahler measure. (This is where the AJ computation on the Kuga varieties, done using our formula with J. Lewis and S. Mueller-Stach, will be summarized). We also look at an application of the toric construction in the non-modular case, to limits of normal functions for families of Calabi-Yau 3-folds.

    Moduli of polarized logarithmic Hodge structures and period maps
    by Sampei Usui Osaka University

    Height and GIT weight
    by Xiaowei Wang The Chinese University of Hong Kong

    In this talk, we will establish a new connection between the weight in the geometric invariant theory and the height introduced by Cornalba and Harris CH and Zhang Z. Then I will explains two applications of this connection.

    Talks will be held at CAB 269 (April 12, 14, 15, 16) and ETL E1 008 (April 13). We have booked the computer lab at CAB 341. map

  • This workshop will bring together scientists working on mathematical modeling of viral disease with a focus on viral evolution and epidemiology, and with particular application to influenza and HIV.

    Please note: People registering after March 25th will not be registered for the dinner on Friday, April 4th. Please inquire at the meeting about the availability of space at the dinner, if you wish to attend.

  • Waves, Vortices, and Climate Modelling

  • Welcome to the 2008 Applied Mathematics Graduate Student Conference (AMGSC) webpage. The conference was held on Saturday, January 26 and Sunday, January 27 at Simon Fraser University. Some students gave short presentations based on past course project or current research.

  • Speaker: Derek Bingham
    Title: Statistical Research in a Collaborative Environment
    Modern statistical research is often motivated by applied problems that arise in other areas of science. Finding solutions to these applied problems leads to collaborations between statisticians and subject-specific researchers. Working in such a collaborative environment brings much benefit to both parties, but is not without challenges. This talk will relate some of my experiences working in such an environment, and how one might build successful long-term collaborative relationships.

    Title: Confidence intervals for proportions and quantiles with application to NHANES
    Speaker: Cindy Feng
    It has been noted that the usual confidence interval for proportions does not perform well for large and small values of p. In surveys the issue is complicated by the survey design and issues of whether to use design effects, effective sample size and effective degrees of freedom arise. The question is which of the many possible confidence intervals available should be recommended for the U.S. National Health and Nutrition Examination Surveys (NHANES) end users and what cautions should be given. In addition, the issues may be different if the interval is actually being used in combination with Woodruff’s method to form confidence intervals for small and large quantiles.

    Title: Median Loss Analysis
    Speaker: Pen Yu
    In classical decision theory in statistics, Wald (1950) first introduced the risk function, and used it to evaluate how good the estimators are. Conventionally, the risk is assumed to be finite in most situations. In other words, we cannot handle the problems of heavy-tail distributions like the Cauchy distribution. In this talk, I will introduce the median version of the risk, called the median loss, and compare it with the risk and other domination criteria. Moreover, we will see that the estimator by the median loss approach is more loss robustness than the estimator by the risk, such as the Bayes estimator.

    Title: Statistical Monitoring of Clinical Trials with Multivariate Response or Multiple Arms Using Repeated Confidence Bands
    Speaker: Lihui Zhao
    Coauthors:
    X. Joan Hu (Simon Fraser University) Stephen W. Lagakos (Harvard University)
    Clinical trials with multivariate response or multiple arms have become increasingly common because of their potential efficiency and cost saving. Interim analyses of such studies are often guided by parametric assumptions for the underlying probability models. There are situations where it is not clear at the outset how the responses differ among the treatment groups and what kinds of differences are clinically meaningful. More flexible designs and monitoring procedures are therefore desirable. In this talk, we extend the repeated confidence bands approach (Hu and Lagakos, 1999) to studies with multivariate target function. We use a recent AIDS clinical trial to illustrate how to apply the multivariate repeated confidence bands (MRCB) approach in practice.

    Title: Prior Sensitivity and Cross-Validation using Sequential Monte Carlo
    Speaker: Luke Bornn
    In a Bayesian setting, adequately approximating the model of interest can be computationally expensive in the order of hours or even days. Prior sensitivity and cross-validation are both tasks that involve repeating this approximation repeatedly, potentially hundreds or thousands of times. In this talk I will demonstrate how sequential Monte Carlo methods can make prior sensitivity and cross-validation feasible in situations where the distribution of interest is not available analytically, reducing computational time by an order of magnitude or more in most settings.

    Title: The Publication Process in Statistics
    Speaker: Paul Gustafson
    Peer-reviewed academic journals are central to scientific life. Scientists of all stripes spend substantial proportions of their time reading, writing, and reviewing for journals. Based on my experiences as an author, a reviewer, an associate editor, and an editor, I will make some comments on how academic journals function, and try to offer some advice on navigating the publication process.

    Title: Finding approximate solutions to combinatorial problems with very large datasets using BIRCH
    Speaker: Justin Harrington
    Over time the boundaries between Computer Science and Statistics have blurred, with a number of disciplines (e.g. Machine Learning) being actively researched in both schools. One such technique is called BIRCH (Balanced Iterative Reducing and Clustering using Hierarchies) (Zhang et al, 1997), which is a data pre-processing tool used for clustering extremely large datasets with a k-means algorithm. The advantage of this algorithm is that it generates "sufficient statistics" with only one pass of the dataset, and these values can then be used instead of the whole dataset for certain applications.
    In this talk we demonstrate this algorithm's application in two fields, namely robust statistics and (if time permits) a new clustering method called Linear Grouping Analysis (Van Aeslt et al, 2006).

    Title: Designs for Computer Experiments
    Speaker: Chunfang Lin
    Latin hypercube designs have been widely adopted in conducting computer experiments. In this talk, we introduce methods for constructing a rich class of Latin hypercube designs with appealing projection and space-filling properties. The class includes many orthogonal Latin hypercube designs that are not available in the literature, as well as nearly-orthogonal Latin hypercubes and two-level orthogonal-array based orthogonal Latin hypercube designs. This is joint work with Randy R. Sitter.

  • The 29th Annual Alberta Statisticians Meeting is sponsored by the Department of Mathematics and
    Statistics and the Faculty of Science at the University of Calgary, and also by PIMS.

    This meeting serves many purposes. It allows faculty and graduate students working in probability and statistics
    at different universities in Alberta to interact, make contacts, and discuss their research. It serves as a training
    vehicle for highly qualified people (HQP) working in probability and statistics. It affords statisticians working in
    the private and non-academic public sector to discuss their problems with academic researchers. In addition,
    it affords graduate students an opportunity to present their work and themselves to possible future employers.

    Registration will be at the door.

    For further information, please contact David Scollnik at scollnik@math.ucalgary.ca.

  • The Cycle Double Cover Conjecture (CDC) was proposed independently by
    P.D. Seymour (1979) and G. Szekeres (1973). The conjecture is easy to state:
    "For finite every 2-connected graph, there is a list of cycles (polygons)
    such that every edge of the graph is an edge of exactly two cycles
    in the list."

    As an example, if the graph is embedded in a surface (without crossing
    edges) in such a way that all faces are bounded by cycles,
    then the boundary cycles of the faces will "double cover" the edges.
    Although the statement of the conjecture is very simple, the solution
    has eluded dozens of attacks over 30 years.

    This conjecture (and its numerous variants) is considered by most graph
    theorists to be one of the major open questions in the field.
    One reason for this is the close connections that this problem has
    with topological graph theory, the theory of Nowhere-zero flows,
    graph colouring and polyhedral combinatorics. MathSciNet lists more
    25 articles with "cycle double cover" (or "double cycle cover") in
    the title.

    The workshop will include some formal presentations
    with the purpose of bringing the participants up to date on
    techniques and recent results. Long collaborative working periods will
    take the majority of the working time.

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    The 19th Annual Canadian Conference on Computational Geometry (CCCG 2007) will
    be held in Ottawa, Canada on August 20-22, 2007 at Carleton University, with a
    welcome reception on the evening of August 19th.

    CCCG focuses on the computational aspects of geometric problems. Computational
    Geometry applies to all fields that touch geometric computing. Application
    areas are as diverse as computer graphics and animation, computer vision,
    CAD/CAM, GIS, pattern recognition, wireless communication, robotics, urban
    planning, graph drawing, or statistical analysis to name just a few.

    CCCG is intended to be a forum, accessible to a broad variety of researchers in
    the area, to disseminate and discuss new results. All submitted papers will be
    refereed, but we have no maximum target on the number of submissions that are
    accepted. All papers that present new, original, and error free results that
    are of interest to the greater computational geometry community will be
    accepted. The intended audience for this conference includes graduate and
    undergraduate students, researchers in the area and members of industry that
    work in areas requiring the use of intensive geometric computation.

  • The International Conference of Theoretical and Numerical Fluid Mechanics
    III is being held in honor of Professors Giovanni Paolo Galdi and Rolf
    Rannacher, in celebration of their sixtieth birthdays. Reflecting their
    interests, it will be an interdisciplinary meeting within the general field
    of mathematical and computational fluid dynamics, devoted mainly to
    Newtonian and non-Newtonian viscous flow. While promoting a high quality of
    mathematical treatment, no area of practical application will be excluded
    due to the present intractability of interesting mathematical difficulties.
    Thus, there will be lectures on turbulence, blood flow, sedimentation,
    fluid structure interaction, flow control, and the dynamical systems
    perspective, as well as key issues of the Navier-Stokes theory.

    Short courses will be offered by Professors Galdi and Rannacher on the two
    days preceding the conference. Professor Rannacher will lecture on
    “Numerical methods for the simulation of fluid-structure interaction”.
    Professor Galdi will lecture on “Topics in the Mathematical Theory of
    Fluid-Solid Interaction”.

    Registration is open to the general scientific and engineering community.
    All registrants are invited to give poster presentations. Also, all
    registrants along with their families are welcome and encouraged to join in
    all of our sponsored social events. PIMS has provided special funds for
    supporting the travel of graduate students to attend this meeting. Graduate
    students wishing such support should apply for it by writing to John
    Heywood at heywood@math.ubc.ca
    .

  • CECM, Maplesoft, MITACS, IRMACS and PIMS are pleased to present "CECM 2007", a summer conference hosted by CECM under the title "Summer Workshop on Computational Mathematics" at Simon Fraser University.

    The Workshop Program includes talks and a poster session which cover diverse topics in mathematics with an emphasis on computation.

    Registration is required.

    For more information, please visit:
    www.cecm.sfu.ca/events/CECM07/