Mervyn Freeman 12th Nov 2014

On Wednesday 12th November, Mervyn Freeman, from the British Antarctic Survey, Cambridge, will give the talk:

Some random walks in space weather

Please note this is being held at an earlier time (2pm)

Mountbatten Room 4025A (53/4025A), Highfield Campus, 2pm. All welcome. Refreshments served after the talk.

Abstract: Space weather – the natural variability of near-Earth space – is a hazard to modern society, with the potential to affect satellite services and electricity supply. It is the fourth highest natural hazard risk on the Government’s National Risk Register, alongside heatwaves and low temperatures. Arguably the greatest source of uncertainty is the substorm – an earthquake-like disruption of near-Earth space that eludes deterministic prediction. In this talk, I will show how substorm occurrence may be understood as a random walk towards an absorbing barrier, similar to the Gerstein-Mandelbrot model of neuron firing in the brain. I will discuss the limits of prediction and similarities to the space weather of Jupiter and Saturn.

Advertisements

Alex Kalloniatis 5th Nov 2014

CS4-20141105-Alex-KalloniatisOn Wednesday 5th October, Alex Kalloniatis, from Defence Science and Technology Organisation, Canberra, Australia, will give the talk:

Networks and synchronisation: mathematical modelling of socio-technical decision making systems

Life Sciences Building (85), room 2207, Highfield Campus, 4pm. All welcome. Refreshments served after the talk.

Abstract: Much of the decision making in structured organisations such as military, business and administrative units is distributed across many individuals, each contributing information that spans the spectrum from simple ‘facts’ about who and what is ‘out there’, to an integrated understanding of what is happening and why, and what will happen in the future – so that future actions can be determined. They also involve a variety of technological systems and displays to facilitate such Situation Awareness and Sense-Making. Such decision making systems may be represented as networks, and the process of making decisions may be represented as the evolution of individual and collective states in time. In this talk I will present my own efforts at encoding such a model in terms of a system of differential equations based on the well known system of synchronising oscillators, the Kuramoto model. I present two adaptations of this model. The first represents two adversary organisations engaging in a competitive process, each seeking to outpace the speed of decision making of the other. The second focuses on a single organisation but structured in the manner of a typical Divisional construct with separate branches performing different organisational functions, operating under different time pressures and cycles. In both cases, rich seemingly unexpected behaviour arises from numerical solution or simulation – there is ’emergence’ – and dynamical regimes lying between order and chaos. I discuss the value of such models in their tractability to explore, for example, optimal network structures, and the scope for expanding such models to find a balance between Levins’ dimensions of Realism, Precision and Generality.

Doyne Farmer 29th October 2014

doynefarmerOn Wednesday 29th October, Doyne Farmer, from the University of Oxford, will give the talk:

A long-term vision for computational economics

Nightingale Building (67) room 1003, Highfield Campus, 4pm. All welcome. Refreshments served after the talk.

Abstract: The ability to simulate phenomena is probably the biggest driver of theoretical progress in physical science during the last 50 years.  The same is not true in economics and social science in general.   Why is this so?  I will argue that the time is ripe for this to happen and present a plan for how it could be done and what breakthroughs are required.  I will review the accomplishments of agent-based models in economics so far, discuss the key theoretical and practical challenges for creating the next generation of models, and present key lessons from the CRISIS project (for which I am scientific coordinator).   I will particularly focus on the need for large scale simulation models, analogous to the global circulation models used in meteorology and climate, and discuss the similarities and differences with meteorology.  Finally I will present a vision of what such large scale models might be like and what they would enable us to do ten or twenty years from now.