Past Industrial and Interdisciplinary Workshops

12 March 2010
11:30
to
13:00
Various
Abstract
• Amy Smith presents: “Multiscale modelling of coronary blood flow derived from the microstructure” • Laura Gallimore presents: “Modelling Cell Motility” • Jean-Charles Seguis presents: “Coupling the membrane with the cytosol: a first encounter”
  • Industrial and Interdisciplinary Workshops
12 March 2010
10:00
to
11:15
Lenny Smith, Dan Rowlands, Tim Palmer, Chris Farmer et al.
Abstract
This will not be a normal workshop with a single scientist presenting an unsolved problem where mathematics may help. Instead it is more of a discussion meeting with a few speakers all interested in a single theme. So far we have: Lenny Smith (LSE) on Using Empirically Inadequate Models to inform Your Subjective Probabilities: How might Solvency II inform climate change decisions? Dan Rowlands (AOPP, Oxford) on "objective" climate forecasting; Tim Palmer (ECMWF and AOPP, Oxford) on Constraining predictions of climate change using methods of data assimilation; Chris Farmer (Oxford) about the problem of how to ascertain the error in the equations of a model when in the midst of probabilistic forecasting and prediction.
  • Industrial and Interdisciplinary Workshops
5 March 2010
10:00
to
13:00
Ralph Brownie and Andy Stove
Abstract
Synthetic Aperture Radars (SARs) produce high resolution images over large areas at high data rates. An aircraft flying at 100m/s can easily image an area at a rate of 1square kilometre per second at a resolution of 0.3x0.3m, i.e. 10Mpixels/sec with a dynamic range of 60-80dB (10-13bits). Unlike optical images, the SAR image is also coherent and this coherence can be used to detect changes in the terrain from one image to another, for example to detect the distortions in the ground surface which precede volcanic eruptions. It is clearly very desirable to be able to compress these images before they are relayed from one place to another, most particularly down to the ground from the aircraft in which they are gathered. Conventional image compression techniques superficially work well with SAR images, for example JPEG 2000 was created for the compression of traditional photographic images and optimised on that basis. However there is conventional wisdom that SAR data is generally much less correlated in nature and therefore unlikely to achieve the same compression ratios using the same coding schemes unless significant information is lost. Features which typically need to be preserved in SAR images are: o texture to identify different types of terrain o boundaries between different types of terrain o anomalies, such as military vehicles in the middle of a field, which may be of tactical importance and o the fine details of the pixels on a military target so that it might be recognised. The talk will describe how Synthetic Aperture Radar images are formed and the features of them which make the requirements for compression algorithms different from electro-optical images and the properties of wavelets which may make them appropriate for addressing this problem. It will also discuss what is currently known about the compression of radar images in general.
  • Industrial and Interdisciplinary Workshops
26 February 2010
10:00
to
11:15
Jorn Dunkel
Abstract
Micron-sized bacteria or algae operate at very small Reynolds numbers. In this regime, inertial effects are negligible and, hence, efficient swimming strategies have to be different from those employed by fish or bigger animals. Mathematically, this means that, in order to achieve locomotion, the swimming stroke of a microorganism must break the time-reversal symmetry of the Stokes equations. Large ensembles of bacteria or algae can exhibit rich collective dynamics (e.g., complex turbulent patterns, such as vortices or spirals), resulting from a combination of physical and chemical interactions. The spatial extent of these structures typically exceeds the size of a single organism by several orders of magnitude. One of our current projects in the Soft and Biological Matter Group aims at understanding how the collective macroscopic behavior of swimming microorganisms is related to their microscopic properties. I am going to outline theoretical and computational approaches, and would like to discuss technical challenges that arise when one tries to derive continuum equations for these systems from microscopic or mesoscopic models.
  • Industrial and Interdisciplinary Workshops
19 February 2010
10:00
to
11:15
Abstract
I have reconstructed multiple palaeoecological records from sites across the British Isles; this work has resulted in detailed time series that demonstrate changes in vegetation, herbivore density, nitrogen cycling, fire levels and air temperature across an 8,000 year time span covering the end of the last glacial period. The aim of my research is to use statistics to infer the relationships between vegetation changes and changes in the abiotic and biotic environment in which they occurred. This aim is achieved by using a model-fitting and model-selection method whereby sets of ordinary differential equations (ODE) are ‘fitted’ to the time series data via maximum likelihood estimation in order to find the model(s) that provide the closest match to the data. Many of the differential equation models that I have used in this study are well established in the theoretical ecology literature (i.e. plant – resource dynamics and plant – herbivore dynamics); however, there are no existing ODE models of fire or temperature dynamics that were appropriate for my data. For this workshop, I will present the palaeoecological data that I collected along with the models that I have chosen to work with (including my first attempt at models for fire and temperature dynamics) and I hope to get your feedback on these models and suggestions for other useful modelling methods that could be used to represent these dynamics.
  • Industrial and Interdisciplinary Workshops

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