Institute of Mathematics and Applied Statistics Seminars

Pure math seminar series
CSSM seminar series

Other seminars

Speaker: Venkat Subramanian, Department of Chemical Engineering, Tennessee Technological University, Cookeville, TN
Title:Modeling Electrochemical Power Sources in Hybrid Environments
Day: Friday 15th December 2006
Location: 15.113 (the Access Grid Room)
Time: 12.30 -1.30pm

Abstract: Analysis of electrochemical power sources (batteries, fuel cells, capacitors, etc) in a hybrid environment (for e.g., hybrid vehicles,mobile-platforms) requires the simultaneous simulation of one or more power sources, a direct-current (DC) motor and other components under a wide range of operating conditions. Existing physics-based models for electrochemical power sources require the solution of many coupled non-linear partial differential equations (PDEs) that represent the physics and chemistry across a variety of technical disciplines. These models require a high computing cost and are therefore not appropriate for the study, design, and optimization of hybrid power sources, including controls, power electronics, and other equipments operating on disparate time scales. While the non-electrochemical components of these systems can be suitably represented by low-order dynamic equations or circuits, there is a distinct lack of component models for
electrochemical power sources where the physics are adequately represented by a minimal set of equations.

The rigorous models for Li-ion batteries are simplified using various mathematical techniques. The simplification process is guided by physical intuition, experimental/theoretical observation and electrochemical principles. The simplified model includes all the physical and chemical phenomena and predicts the expected behavior in reduced computation time. The reduced-order models developed help analyze Li-ion batteries in stack and hybrid environments without having to use empirical or lumped-parameter models. In addition, the simplified models help predict and understand transport and kinetic limitations observed in various experiments (AC impedance, cyclic voltammetery, etc).

The presentation will also discuss current efforts in modeling and analyzing PEM fuel cells and other electrochemical systems. [Speaker's email: vsubramanian@tntech.edu]

Speaker: Dr Scott McCue, Griffith University
Title:Free-surface flows: analytical and numerical" approaches
Day: Thursday 9 November
Location: 15.113 (the Access Grid Room)
Time: 12.30 -1.30pm

Abstract:[not available]

Speaker: Chris Coleman, School of Electrical and Electronic Engineering, University of Adelaide
Title:Radio Wave Propagation Research at the University of Adelaide
Day: Wednesday, 1 November 2006
Location: 15.113 (the Access Grid Room)
Time: 12.30 -1.30pm

Abstract:This talk will give and overview of research into radio wave propagation at the University of Adelaide. Much of this work is concerned with propagation in radar systems, but there is also some work on the propagation in bush fires and some more fundamental theoretical work.

Speaker: Efim Pelinovsky, Institute of Applied Physics, Nizhny Novgorod, Russia
(Pelinovsky@hydro.appl.sci-nnov.ru)
Title:Rogue Waves: Facts, Theories and Modelling
Day: Tuesday, 10 October
Location: 15.113 (the access grid room)
Time: 12.30 -1.30pm

Abstract: A review of physical mechanisms of the rogue wave phenomenon is given. The data of marine observations as well as laboratory experiments are briefly discussed. They demonstrate that freak waves may appear in deep and shallow waters. Simple statistical analysis of the rogue wave probability based on the assumption of a Gaussian wave field is reproduced. In the context of water wave theories the probabilistic approach shows that numerical simulations of freak waves should be made for very long times on large spatial domains and large number of realizations.

The following mechanisms of the rogue wave formation are considered: dispersion enhancement of transient wave groups, geometrical focusing in basins of variable depth, wave-current interaction, nonlinear modulational instability (Benjamin-Feir instability), and wind flow action. Specific numerical simulations were performed in the framework of various mathematical models: the nonlinear Schrodinger equation, the Davey-Stewartson system, the Korteweg-de Vries equation, the Kadomtsev-Petviashvili equation, the Zakharov equation, the fully nonlinear potential equations, and their forcing versions. The results of the numerical experiments show the main features of the physical mechanisms of rogue wave phenomenon. They are used to estimate the rogue wave life-time and explain the observed data.

Speaker: Dr Mary Myerscough, School of Mathematics and Statistics, University of Sydney
Title:Deterministic and stochastic models for nest-site selection by honeybees
Day: Thursday 14 September 2006
Location: Rm15.206
Time: 12.30 -1.30pm

Abstract: In spring a swarm of bees may leave a hive to establish a new colony. The swarm settles a few hundred metres away from the hive and scouts go out to search for a suitable cavity for a new home. A returning scout who has found a suitable nesting site communicates the location and quality of the site to her nestmates by performing a waggle dance. Most scouts visit only one potential nest site, yet the swarm is still able to choose the best available site.

I present two quite different models for this process. The first model, which is deterministic, is based on ideas from population biology, which encapsulates the important features of the house-hunting process and explains how bees' individual behaviour leads to a collective decision.

It is clear, however, from observation and from published data that there is considerable variation among bees in their success at communicating their dance information to others. Even though the deterministic model suggests that bees are be able to correctly choose the best site, this is not always what happens in real life! Therefore we have constructed a stochastic model using a density dependent Markov process so that we can consider the effect of random behaviour on the swarm's decision.

Speaker: Bob Anderssen, CSIRO, Mathematical and Information Sciences, Canberra.
(Bob.Anderssen@csiro.au)
Title:Pianos, Pasta and Plants - Their Impact on Mathematics
Day: Thursday 17 August 2006
Location: CEDIR presentation room, Level 1, Bld 20
Time: 12.30 -1.30pm

Abstract: "The profound study of nature is the most fertile source of mathematical discoveries."J. P. J. Fourier

Clearly, Fourier understood mathematics' role in solving challenging real-world problems and how that catalyses the development of new mathematics or new interpretations of established mathematics. Mathematics allows a rigorous framework to be defined in which specific matters can be resolved. The impact arises when the matter under investigation leads to a question which can only be answered after the further development of established or new
mathematical results.

Thus, from an R&D perspective, it is "applications" that have the most profound effect on the directions in which mathematics develops and evolves. As V. I. Arnold once remarked "My best pure mathematics was in applied mathematics, and my best applied mathematics was in pure mathematics".

Applications connected with vibrating piano strings, the drying of pasta and plant breeding will be used to illustrate some of the different ways in which the impact occurs.

Speaker: Dr Rabinovich, Moscow Institute of Oceanology
Title:Boxing Day Sumatra Tsunami-2004 and its impact on the Australia Coast
Day: Tuesday, 9 May 2006
Location: 15.113
Time: 12.30 -1.30pm

Abstract: [no abstract]

Speaker: Dr Scott McCue, School of Science, Griffith University
Title:Hele-Shaw flows
Day: Thursday 4 May 2006
Location: 15.113
Time: 12.30 -1.30pm

Abstract: [no abstract]

Speaker: Geoff Lee, ABS
Title: ABS data for researchers: selected directions
Day: Friday 31 March 2006
Location: Union Function Centre (Bld 11)
Time: 11.30 -12.45pm

Abstract: Geoff Lee, head of the Methodology Division at the Australian Bureau of
Statistics, will given an overview talk describing some of the ways ABS is working to make official statistical data more accessible to researchers. He will mention the ABS website, and electronic publishing; confidentialised unit record files, how you access them and where ABS would like to head with them; some of the more interesting datasets under development in ABS at the moment; and finally, the National Data Network concept, what it is now, and where it is headed. Geoff's more than happy to receive questions, and where he's able, will do his best to answer them!

Speaker: Prof. Julian Gale, Nanochemistry Research Institute, Department of Applied
Chemistry, Curtin University of Technology, Perth
Title: Challenges in numerical electronic structure theory
Day: Part A: Tuesday 29 November 05; Part B: Thursday 1 December 05.
Location: 15.108
Time: 12.30 -1.30pm

Abstract: The last decade has seen a major change in the range of techniques available for the calculation of the electronic structure of solids. Instead of being dominated by Gaussians and planewaves, there are now many different basis representations for wavefunctions being explored including real space grids, wavelets, radial splines and finite elements. As yet there is no clear winner in terms of ease of use and numerical efficiency.

In this presentation, an introduction to the SIESTA methodology for linear scaling numerical electronic structure theory will be given. The merits and problems of the approach will be discussed, including the issues of fast solution of the Coulomb problem, choice of numerical integration methods, the minimization of a complex functional and sparse matrix eigensolution. Comments and suggestions from qualified mathematicians will be most welcome!

Speaker: Professor Bruce Berndt, the Department of Mathematics at the University of Illinois
Title: Ramanujan's Lost Notebook
Day: Tuesday 18 October 2005
Location: Belmore Room, Function Centre (Bld 11)
Time: 12.30 -1.30pm

Abstract: Srinivasa Ramanujan, generally regarded as the greatest mathematician in Indian history, was born in 1887 and died in 1920 at the age of 32. Most of his work was recorded without proofs in notebooks. In the spring of 1976, while searching through papers of the late G. N. Watson at Trinity College, Cambridge, George Andrews found a sheaf of 138 pages of Ramanujan's work. In view of the fame of Ramanujan's "ordinary" notebooks, Andrews naturally called this collection of sheets Ramanujan's "lost notebook." This work, comprising about 650 results with no proofs, arises from the last year of Ramanujan's life and represents some of his deepest work. After a brief history of Ramanujan's life and notebooks, the history and origin of the lost notebook will be given. The remainder of the lecture will be devoted to a survey of some of the most interesting entries in the lost notebook. These include claims in q-series, theta functions, continued fractions, integrals, partitions, and other infinite series.

The lecture should be of wide interest.

Speaker: Dr. Chunsheng Lu, Centre for Advanced Materials Technology (CAMT), School of
Aerospace, Mechanical and Mechatronic Engineering, University of Sydney
Title:Modelling of novel physical behaviour in nanostructured materials
Day: Wednesday 7 September 2005
Location: 15.111
Time: 12.30 -1.30pm

Abstract: Materials based on nanometre-sized structural components exhibit unique electronic, optical, magnetic, and mechanical properties, which are often remarkably superior to those of their conventional counterparts. Using two case studies (superhard nanocomposite coatings and polymer-clay nanocomposites) as examples, the physical and statistical/mathematical modelling of novel emerging behaviour in nanostructured materials will be briefly discussed in this talk.

Speaker: Dr. Weihua Li, Mechatronic Engineering
Title: "Magnetorheological fluids" and "Manipulation and separation of micro- and nano- biological particles using dielectrophoresis"
Day: Thursday 18th August 2005
Location: 15.111
Time: 11.30 -12.30pm

Abstract: In the presentation, I will introduce my two major research interests: (a) Magnetorheological (MR) Fluids & Applications; (b) Manipulation and Separation of Micro- and Nano- Biological Particles Using Dielectrophoresis (DEP). For the MR research, the mechanisms, materials, properties, and applications of MR technology will be covered; the challenges as well as the comparison with electrorheological fluids will be described. For the DEP research, our new ARC Discovery Project on "DEP Manipulation of Biological Particles" will be described. Some initial numerical and experimental research results will be presented. The potential applications in bioMEMS will be discussed.

Speaker: Dr Andrew Minett, The Intelligent Polymer Research Institute
Title:Carbon nanotubes
Day: Wednesday 17 August 2005
Location: 15.111
Time: 11.30 -12.30pm

Abstract: Since their discovery, carbon nanotubes have attracted an enormous amount of experimental and theorical interest.

Speaker: Dr. Benchawan Wiwatanapataphee, Mahidol University, Thailand
Title:A 3-D simulation of unsteady state blood flows in stenotic arteries using Carreau Model
Day: Thursday 16 August 2005
Location: 15.111
Time: 12.30 -1.00pm

Abstract: [not available]

Applied Mathematics and Mathematical Modelling meeting, 7 July, Rm15.206.

• 2:00 - 2:40 pm ~ Professor Jim Hill (School of Mathematics & Applied Statistics) Title: Nanomechanics
• 2:50 - 3:20 pm ~ Professor Geoff Spinks (IPRI, University of Wollongong) Title: Some unusual observations relating to dimension changes occurring in pH-sensitive hydrogels
• 3:20 - 3:50 pm ~ Dr Frank Bierbrauer (School of Mathematics & Applied Statistics) Title: Hydrogel Drug Delivery: Diffusion Models
• 4:00 - 4:30 pm ~ Dr. Steve Barry (Australian Defence Force Academy, Canberra) Title: Interdisciplinary teaching of engineering students -- A problem based approach using Matlab.
• 4:30 - 5:00 pm ~ James Caunce (Australian Defence Force Academy, Canberra) Title: Modelling a wool scour bowl

Please find the abstracts below.

Dr. Steve Barry (Australian Defence Force Academy, Canberra) Title: Interdisciplinary teaching of engineering students -- A problem based approach using Matlab.

Abstract: Who should teach Numerical Methods to Engineering students? At our university the computer scientists, mathematicians and engineers all claimed jurisdiction and fought over the lucrative EFTSUs. So management told us we had to share it. What resulted was a problem based course taught simultaneously by three lecturers. Every two weeks the engineer posed a `real engineering' problem that the students had to complete. The mathematician gave the students a lecture on the background mathematics and some numerical methods. The computer scientist talked to them about error propagation, computer limitations and so on. Each assignment reflected our individual perspectives of what Numerical Methods meant. By the end, the students had tackled six unique assignments on the fundamental topics (integration, interpolation, and so on) and had reluctantly realised that they knew how to set up and solve a real problem, program the problem using Matlab, and understand some of the relevant issues behind the methods.

Setting up a course like this is not easy. Hence this seminar will discuss how we overcame the numerous obstacles and designed a course which we felt was a great way to teach engineering students.

Dr Frank Bierbrauer (School of Mathematics & Applied Statistics) Title: Hydrogel Drug Delivery: Diffusion Models

Abstract: An approximate list of topics covered in this talk is: 1) Introduction to biomedical hydrogels * types * examples of uses 2) Drug delivery devices * reservoir * matrix * swelling controlled release 3) Diffusion of drugs * Fickian diffusion * molar flux * time dependent diffusion 4) Static drug Delivery * fractional drug release * aspects 5) Dynamic drug delivery (swelling) * molar flux * time dependent diffusion * moving boundary * aspects * changing diffusion coefficient

James Caunce (Australian Defence Force Academy, Canberra) Title: Modelling a wool scour bowl

Abstract: Wool scouring is the process of washing dirty wool once it has been removed from the sheep's back. It involves running the wool through a set of `scour bowls' filled with water and cleaning agents to remove contaminant into settling tanks. The purpose of developing a model is to gain a better understanding as to the operating parameters that will produce effective and efficient scouring of wool at Michell's scouring plant in Adelaide.

Our model simulates, using the advection-diffusion equation, the movement of contaminants within a scour bowl. Results start with simple systems and work up to more realistic scenarios of four settling tanks. The effects of varying the important parameters are investigated and interesting but simple relationships found which give insight into the subtle dynamics of a scour bowl.

Professor Geoff Spinks (IPRI, University of Wollongong) Title: Some unusual observations relating to dimension changes occurring in pH-sensitive hydrogels

Abstract: Many hydrogels produce enormous volume changes in response to a change in the pH of the surrounding electrolyte medium. These volume changes may be useful for a range of applications including artificial muscles and controlled release devices. We are interested in developing hydrogels for artificial muscles and have been studying the volume changes that occur when the hydrogel is subject to an external mechanical load. Under such circumstances the change in mechanical properties of the hydrogel must be considered in addition to the "free" swelling or contraction behaviour. Not all of our experimental results fit with the simple models of that have been previously developed.

Speaker: Dr Ron Thatcher (School of Mathematics, The University of Manchester, UK)
Title: Flame edges in a counterflow
Day: Thursday 21 April 2005
Location: 15.111
Time: 12.30-13.30

Abstract: In a recent comprehensive review article entitled Edge-Flames, John Buckmaster [1] describes the nature of edge flames, where they arise and their importance in the study of combustion. Edge flames, or as we call them flame edges, give us information about how flames propagate. This talk will discuss a numerical study of flame edges in a counterflow describing the range of phenomena that can arise. We shall consider the results in [2] concerning flame edges that breaks up into cellular flames and isolated flame tubes when the
Lewis number of the fuel is less than one. We shall also describe the results in [3] on multiple propagations speeds of flame edges for Lewis numbers greater than one. Finally we shall discuss some recent work done in collaboration with Joel Daou extending his work in [4] on flame edges in the presence of heat loss.

References:
[1] Buckmaster, J. (2002) Edge-Flames. Progress in Energy and Combustion
Science 28. 435-475.
[2] Thatcher, R.W., Dold, J.W. (2000). Edges of flames that do not exist:
flame-edge dynamics in a non-premixed counterflow. Combustion
Theory and Modelling 4. 435-457.
[3] Thatcher, R.W., Omon-Arancibia, A.A. Multiple speeds of edge flame
propagation for Lewis numbers above one. Submitted, October 2004.
[4] Daou, R., Daou, J., Dold, J.W. (2003) Effect of heat-loss on flame-edges
in a premixed counterflow. Combustion Theory and Modelling 7.,
221-242.

Speaker: Yury Stepanyants (Australian Nuclear Science and Technology Organisation)
Title:Compound solitons and compactons in systems with large-scale dispersion
Day: Thursday 13 April 2005
Location: 15.111
Time: 12.30 -1.30pm

Abstract: As is known, the wave-breaking phenomenon caused by nonlinearity can be averted either by small-scale dissipation, described by Bateman-Burgers equation, or small-scale dispersions, described by Korteweg-de Vries (KdV) equation. In both these cases, steady-state solutions in the form of shock waves, periodic cnoidal waves, or solitons appear as a result of interplay between nonlinearity and dissipation/dispersion.

In this talk, after an extensive tutorial introduction, I will discuss whether the large-scale dispersion can prevent wave-breaking. The situations where the large-scale dispersion is important in physical systems are widely spread. The corresponding model equation, the reduced Ostrovsky equation, has the same universality as the classical KdV equation. It was derived for many applications including waves in oceans, nonlinear acoustics, plasma physics, relaxing media, media with random parameters, etc. Detailed analysis of solitary and periodic stationary solutions to this equation will be presented in the talk. The relationship of the reduced Ostrovsky equation with its full version combining quadratic nonlinearity with two types of dispersion, small-scale and large-scale, will be also discussed. An interesting specific feature of these equations, the zero-mass integral, will be pointed out, and its effect on the solution structure will be studied. Different types of compound solitons, spikons (sharp-crest solitons with infinite derivatives), loop solitons, compactons (solitons on a finite support), and periodic waves will be presented and classified.

Speaker: Dr. Achim Casties from ac3
Title: High Performance Computing at ac3
Day: Thursday 7 April 2005
Location: ITS presentation room, Level 2 Building 17
Time: 12.30 -3.30pm

Abstract: The workshop will discuss issues such as
- the different platforms at APAC and ac3
- types of HPC
- the queueing system in detail
- batch scripts
- short view at OpenMP and MPI
- resource allocation

This training session should substantially increase users' hpc skills. It is worth attending for part of the 3-hour workshop if you have another commitment. Contact A/Prof Tim Marchant for more details.

Speaker: Dr Olivier Thas, Ghent University, Belgium
Title:EleStat: A collection of tools for an e-course in statistics
Day: Wednesday 30 March 2005
Location: 15.206
Time: 6.30 -7.30pm

Abstract: In recent years there has been an increasing interest in using computers intensively in statistics courses. The ultimate goal is to develop a complete independent e-course that replaces all lectures.

In Belgium, the government has given grants for such innovative projects. Since the late 1990’s I have been involved in some of these projects. In this talk I will give an overview of the efforts that we have done, and I will present some of the tools that we have developed so far.

During the presentation, I will illustrate some applets and show some of the web-based individualised exercises. I will tell about our experience with these tools, and how students react. Finally, I will say something about how these tools may be combined into a complete independent e-course, but it will become clear that there is still a lot of glue missing to make it a strong coherent course that perhaps one day may replace the lecturer.

Abstract: The steady isobaric combustion behaviour and combustion instability of premixed burner-stabilized flames undergoing a direct one-step irreversible Arrhenius-type exothermic global reaction with a constant but general Lewis number is studied in the physically interesting limit of large activation energy. The main concern of this work is to study analytically the behaviour of a flame stabilized in a premixed tubular flame burner. The asymptotic structure and diffusional-thermal instability of a planar premixed burner-stabilized flame suffering either upstream or downstream volumetric heat loss with a rate described by a linear dependence on temperature is studied to gain an understanding of the role of upstream (i.e., in the unburned region) and downstream (i.e., in the burned region) heat losses on the structure and instability of premixed burner-stabilized flames. The asymptotic structure and pulsating instability of premixed tubular flames is then analysed for two cases: either a boundary condition for mass fraction involving convection and diffusion of the reactant at the burner (Hirschfelder condition) or a plug flow boundary condition for mass fraction.

Background

Miccal has both a Bachelor of Mathematics and a Bachelor of Engineering (Chemical) from the University of Newcastle. He stayed at Newcastle for postgraduate study where he has recently submitted a PhD in Engineering (Chemical) on the topic of his seminar

Speaker: Sayed Hoseini, PhD candidate, UoW
Title:Solitary wave interaction for the higher-order NLS equation
Day: Wednesday 23 March 2005
Location: 15.111
Time: 12.30 -1.00pm

Abstract: [no abstract]

Speaker: Dr Pam Davy
Title: Introduction to Latex on PC
Day: Wednesday 16 March, 9.30 - 10.30 or Monday 21 March, 9.30 - 10.30 (repeat)
Location: 15.210 (Horner Lab)

Abstract: A hands-on introduction to using LaTeX via the WinEdt editor on PC for the purpose of typesetting theses and presentation overheads, for Honours and postgraduate students.

Speaker: Eugenio Fedriani Martel, Associate Professor at Pablo de Olavide University, Sevilla
Title: A First Approach to Topological Graph Theory
Day: Thursday 17 March 2005
Location: 15.206
Time: 12.30 -1.30pm

Abstract: We begin with a brief summary of the most basic definitions in Graph Theory directed to the introduction of the notion of a graph drawing, or embedding, which implies that its vertices are represented by points in the Euclidean plane, its edges are represented by curves between these points, and different curves meet only in common endpoints. We also explain the concept of outerplanarity and its generalizations, giving some recent results about these concepts. [Slides of the talk are available at http://www.uow.edu.au/~adamp/PMSeminar.html]

Abstract: The Todd--Coxeter Coset Enumeration Procedure is a cornerstone of computational group theory. We discuss an illuminating geometric interpretation and some applications.

Abstract: [no abstract]

Abstract: [no abstract]

Seminars in 2004

Seminars in 2003

Updated: Oct 05