What's On at UWA

The aim of this course is to introduce you to basic statistics. It will cover descriptive statistics (means and standard deviations); data exploration; basic categorical data analysis; simple linear regression and basic analysis of variance (ANOVA). The statistical package SPSS will be used to illustrate the ideas demonstrated. The course will be held in a computer laboratory allowing participants to immediately apply the material covered through a series of practical examples.

Dugald MacPherson (University of Leeds)

will speak on

Metrically homogeneous graphs

at 3pm Friday February the 21st in Blakers Lecture Theatre.

Abstract:

A `homogeneous structure' is a countably infinite relational structure M (e.g. graph, k-uniform hypergraph, digraph,...) with the property that every isomorphism between finite induced substructures of M extends to an automorphism of M. These are constructed by an amalgamation method developed by Fraisse (and independently Jonsson) in the 1950s. There are classification results, often very hard, in restricted contexts (e.g. graphs, partial orders, digraphs, totally ordered graphs) but in general classification seems out of reach.

I will discuss an attempt to classify `metrically homogeneous graphs', that is, countably infinite graphs M which become homogeneous when enriched by binary `distance relations' corresponding to graph-distance in M. This notion generalises distance transitivity for countably infinite graphs. Cherlin has produced a `catalogue' of metrically homogeneous graph and conjectures that it is complete. In joint work in progress with Amato and Cherlin, we verify the conjecture for metrically homogeneous graphs of diameter at most three.

Eric Swartz (UWA)

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Subgroup covering numbers of symmetric groups

at 3pm Friday February the 28th in Weatherburn Lecture Theatre.

Abstract:

Let G be a group. The subgroup covering number of G is defined to be the least integer m such that G is equal to the set theoretic union of m proper subgroups of G. In 2005, Maroti determined the subgroup covering number for the symmetric group S_n, when n > 9 is odd, and he provided bounds for sufficiently large even values of n. I will discuss these previous results, joint work with Luise-Charlotte Kappe and Daniela Nikolova towards filling in the gap for small values of n, and ongoing work to determine the exact value for large even values of n.

New to the club this year? Want to meet some of the other new people, some older people, and do some computer stuff? At 5pm this Friday, all Freshers and new members should come on up to the loft (just above the clubroom; see your fresher guide) to break the ice on your UCC experience. There'll be a few short presentations and introductions on how to make the most of all the services the club supplies, including a basic introduction to Linux. As an added incentive, all first time members get FREE pizza!

Binzhou Xia (Peking University)

will speak on

Factorizations of almost simple groups with a soluble factor

at 3pm Friday March the 7th in Weatherburn Lecture Theatre.

Abstract:

Factorizations of almost simple groups arise in many contexts. I will talk about the factorizations with one factor soluble, including construction of examples in classical groups and the classification result.

Come along and hear from Teach for Australia about their 2-year graduate program. This session will deliver information about the program, the application process, and an opportunity to ask an alumnus about what the experience was like.

"Our award-winning leadership program affords an accelerated two years of unprecedented personal growth and a Masters level of professional training. Come along to ask an alumnus why Australia's most outstanding young leaders are choosing our associate experience to rapidly advance their careers and make an impact on educational inequity".

All disciplines (particularly Science and Maths Graduates) outside of education are encouraged to attend and find out more.

UCC's AGM, for the election of express purpose of electing the eight new committee members for 2014: president, vice president, treasurer, secretary, three ordinary commmittee members (OCMs), and one fresher representative (fresher rep).

Send all nominations and agenda items to [email protected]. The current agenda can be found at http://wiki.ucc.asn.au/AGM2014Agenda.

If you don't know where the Council Meeting Room is, join the group leaving the clubroom just before 1pm, on Tuesday, 11th of March.

Hope to see lots of people there!

John Bamberg (UWA)

will speak on

The brilliant career of Frédéric Vanhove

at 3pm Friday March the 14th in Weatherburn Lecture Theatre.

Pablo Spiga (Universita' di Milano-Bicocca)

will speak on

Have we ever tried to count Cayley graphs?

at 3pm Friday March the 21st in Weatherburn Lecture Theatre.

Abstract:

In this talk we give some elementary upper bounds on the number of finite Cayley graphs. The asymptotic number of Cayley graphs is much harder to pin down and we give a brief outline of the main technique and the main ingredients needed for this counting. On the way we leave some problems on oriented Cayley graphs and tournaments.

In the week beginning 24 March 2014, iVEC will offer the following short courses on supercomputing topics:

Introduction to iVEC: 1:00 – 2:00pm Mon 24th March

Introduction to Linux: 3:00 – 4:00pm Mon 24th March

Introduction to Supercomputing: 10:00am – 4:00pm Tues 25th March

Developing with MPI and OpenMP: 10:00am – 4:00pm Wed 26th March

Debugging with DDT: 10am – 12:00 noon Thurs 27th March

Introduction to Optimisation and Profiling: 1:00 – 4:00pm Thurs 27 March

Courses are delivered in a face to face classroom style. Attendees are encouraged to bring and work on their own laptops. Staff from the Supercomputing Team will be facilitating so you can meet and chat with them.

Free parking available on-site.

Courses are free of charge and open to all, however places are limited.

Light refreshments and lunch will be provided on each day (no lunch on Monday).

Register online at http://www.ivec.org/ai1ec_event/ivec-supercomputing-training-february-2014-2/?instance_id=

Michael Zieve (University of Michigan)

will speak on

Primitive groups, diophantine equations, and functional equations

at 3pm Friday March the 28th in Weatherburn Lecture Theatre.

Abstract:

I will explain how results about primitive groups play a crucial role in proving results about diophantine equations and functional equations. A sample application is that, for any polynomial f(X) with rational coefficients, the function Q-->Q defined by c --> f(c) is (<=6)-to-1 over all but finitely many values.

Cai-Heng Li (UWA)

will speak on

Edge transitive dessins d'enfant

at 3pm Friday April the 4th in Weatherburn Lecture Theatre.

Abstract:

A 2-cell embedding of a bipartite graph in an orientable surface is called a dessin d'enfant. Thus a dessin d'enfant is an orientable bipartite map. I will present an explicit representation of an edge transitive dessin in terms of a group with two distinguished generators, and apply it to study the dessin.

There will be presentations by international visitors, games, prizes, a photo booth, treats on offer and lots and lots of information about exchange and study abroad opportunities for UWA students.

Come along to Profectus UWA's Inaugral 2014 AGM on Tuesday April 8. If you are passionate about business and entrepreneurship be sure to drop by at 1pm to learn more about our agenda. We will answer any questions you have about Profectus and events being held this semester!!!

Steven Noble (Brunel University)

will speak on

Graphs are to matroids what ribbon graphs are to ...?

at 3pm Friday April the 11th in Weatherburn Lecture Theatre.

Abstract:

Much of the combinatorial structure of an abstract connected graph is encoded in its set of spanning trees. These form one of the canonical examples of the bases of a matroid. Ribbon graphs contain extra topological information on the embedding of the underlying abstract graph in a surface. The structures playing the role of spanning trees are the subgraphs having one boundary component. The combinatorial structure which they form is a delta-matroid, which roughly speaking is like a matroid except that the bases do not need to have the same size. We will discuss three classes of delta-matroids, some natural operations on ribbon graphs which correspond to natural operations on delta-matroids, give an excluded minor theorem for one of the classes of delta-matroids and, time-permitting describe the Bollobas-Riordan polynomial which forms one way of generalizing the Tutte polynomial to ribbon graphs.

Michael Giudici (UWA)

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Some recent results on elusive groups

at 3pm Friday May the 2nd in Weatherburn Lecture Theatre.

Abstract:

Every transitive permutation group has a derangement of prime power order but not necessarily a derangement of prime order. A transitive permutation group is called elusive if it has no derangements of prime order. I will talk about some recent results on this topic including elusive groups of automorphisms of graphs of small valency and a new construction of elusive groups.

Luke Morgan (UWA)

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Locally-transitive graphs and their vertex stabilisers

at 3pm Friday May the 9th in Weatherburn Lecture Theatre.

Abstract:

Let D be a graph with a group of automorphisms G and suppose that D is G-locally-arc-transitive (for each vertex x of D the vertex stabiliser G(x) acts transitively on the neighbourhood of x). Fixing the valency of D one can ask if there is a bound on the order of G(x)? For valency three there are fundamental results due to Tutte and Goldschmidt. We'll instead fix the `local actions’, that is, the possible permutation groups induced on neighbourhoods in D (there can be at most two of these) and ask again: is there a bound on the order of G(x)? I will revisit some of the interesting results on this question. Then I will talk about some recent results like: when there can be a bound; when there is no bound; given a bound (and a little more) an instance when G(x) can be completely determined. Spread throughout this is joint work with Giudici, Giudici-Ivanov-Praeger and Spiga-Verret.

Denis Weaire

Gledden Visiting Fellow, Institute for Advanced Studies, UWA

and

School of Physics, Trinity College, Dublin, Ireland

will speak on

Classic problems of packing in 2d, 3d and on a cylinder

at 3pm Friday May the 16th in Weatherburn Lecture Theatre.

Abstract:

Some classic problems of optimal packing are reviewed: the Kepler Problem, the Kelvin Problem, and cylindrical packings of spheres and disks. The latter are tentatively associated with the celebrated phenomenon of spiral Phyllotaxis, much in evidence in the splendid gardens of UWA. If the speaker omits or forgets anything, it is to be found in the book Pursuit of Perfect Packing, T. Aste and D. Weaire, 2nd Edition.

iVEC and CSIRO invite you to attend training on MOOSE – Multiphysics Object-Oriented Simulation Environment. The MOOSE platform is a general problem solver that can accommodate many mathematical models. It has recently been released as open-source software, making it even easier for academic researchers to adopt. Some of the capabilities of MOOSE include:

Fully-coupled, fully-implicit multiphysics solver

Dimension independent physics

Automatically parallel (largest runs >100,000 CPU cores!)

Modular development simplifies code reuse

Built-in mesh adaptivity

Continuous and Discontinuous Galerkin (DG) (at the same time!)

Intuitive parallel multi scale solves

Dimension agnostic, parallel geometric search (for contact related applications)

Flexible, plugable graphical user interface

~30 plugable interfaces allow specialisation of every part of the solve

More information about MOOSE can be found at the MOOSE website: http://mooseframework.org

Please refer to the URL for the Program Overview and more information.

Cody Permann’s visit is sponsored by CSIRO to support researchers in WA. If you would like to arrange a meeting with Cody, please contact Thomas Poulet <[email protected]>, other enquiries should be directed to Rebecca Hartman-Baker <[email protected]>.

Although the training is free, you must register your attendance (through the URL) as places are limited. The intensive program builds a solid foundation for MOOSE use, so attendance on all three days is advised.

Gordon Royle (UWA)

will speak on

Chromatic roots of graphs and matroids

at 3pm Friday May the 23rd in Weatherburn Lecture Theatre.

Abstract:

The location of the real and/or complex roots of the chromatic polynomial of a graph has been studied for many years, both by combinatorial mathematicians and statistical physicists, yet despite this many fundamental questions remain unsolved. And even though the chromatic polynomial is most generally a matroidal concept, very little indeed is known about the location of chromatic roots of matroids that are not graphic or cographic. In this talk, I will present a necessarily-personal survey of the major results and my favourite open problems in this area.