Debate on wind energy on "The Politics Show" - BBC1 mid-day Sunday 9th December
I'm interested (like everyone else on the planet) in the renewable energy debate, so when I saw a special report on tomorrow's announcement on new planning laws to facilitate the implementation of off-shore wind farms around the coast of Great Britain, I was interested, and took a few (very brief) brief notes, which are reproduced below. Being "The Politics Show", all the arguments naturally revolved around political and public opinion issues, with no mention of technical issues - the closest they got to that was a (perfectly valid, in my view) question regarding an over-reliance of the national grid on wind-energy: what happens if the wind stops for a long period of time (e.g. a week)?? Interesting nonetheless...
Report on off-shore wind power:
- Expansion of offshore wind farms - new planning laws to be announced tomorrow.
- 20% EU target for renewable energy production by 2020.
- Significant obstacles to this happening.
- However, very expensive for the amount of energy produced.
- Consumers will pick up the tab for offshore wind for subsidies - in addition to the already existing subsidies for on-land wind farms.
- RSPB (Royal Society for the Protection of Birds) also has concerns regarding sea-birds and migration routes.
Interview with John Hutton (Government business minister):
- Must facilitate shift to low-carbon use, and ability for Britain to supply own energy (and in a clean way.
- How much will be generated: all electricity used by households in the UK if all of the resources round the coast is used.
- 1GW from offshore at moment => want 34GW in 12 years (!)
- No single technology will solve energy problems, but wind power will be a major part.
- The choices can't be postponed - decision must be made now.
- The planning laws are changed with announcement tomorrow- at end of day, it will be private companies who will actually build the turbines.
- There will mean increases in costs for the consumer.
- What about over-reliance on wind: stressed need for a balanced approach to energy production.
- Will 20% target be met? No - not by 2020.
Interview with Alan Duncan (Conservative energy brief):
- Largely agrees with announcement. The coastline should be used.
- Electricity prices will go up: yes, but stability of carbon based fuels not guaranteed in the future, and it the difference in cost between renewables and carbon-based energy production which is of importance.
- Both bottom-up and top-down energy policies needed: both - Nuclear energy needs to be part of the energy mixture - though without subsidies.
Sunday, December 09, 2007
Wednesday, December 05, 2007
Encephalon #37
The 37th issue of Encephalon is now up (well, two days ago) at A blog around the clock. I've missed the last couple, so it's nice to catch up on some good blogging. Two particularly caught my eye this time around:
- From Brain in a vat comes a review on a paper on the perceived importance of paper authors, if there are more than one. As well as covering general trends, it looks at how the perceived importance of the author is if he/she is listed first, last or in the middle.
- From Neurophilosophy comes a series of four posts on axon guidance, with particular regard to growth cones (link to first part). The final part summarises nicely, and discusses some issues in need of clarification to further our understanding of axon guidance.
- From Brain in a vat comes a review on a paper on the perceived importance of paper authors, if there are more than one. As well as covering general trends, it looks at how the perceived importance of the author is if he/she is listed first, last or in the middle.
- From Neurophilosophy comes a series of four posts on axon guidance, with particular regard to growth cones (link to first part). The final part summarises nicely, and discusses some issues in need of clarification to further our understanding of axon guidance.
Tuesday, November 27, 2007
"Modelling natural action selection"
Introduction to the Special Issue "Modelling natural action selection"
Philosophical Transactions of the Royal Society London B
September 2007
A special issue containing fourteen papers on various aspects of modelling action selection in animals and humans. There are multiple methods in the study of biological action selection ("of deciding 'what to do next'"), each approaching the problem from different points of view: be it ethology or psychology studying the biological systems, or artificial intelligence or artificial life attempting to build artefacts based on the biological principles. These differing approaches may be characterised by distinguishing between the analytical and synthetic methods in the behavioural and brain sciences, as proposed by Braitenberg.
The analytical method seeks to describe transitions in behaviour (and to explain why they occur in any given context), either functionally through reference to some concept of utility, or mechanistically through reference to underlying neural systems. It is at the overlap between these two approaches that modelling (the "synthetic" approach - the creation of artificial systems which behave as natural ones) has an increasing influence: "what would it take to build a system that acts in this way?" It is not only formal mathematical models which are of interest, but also, and in cooperation, simulations for which mathematical solutions are intractable or unknown. This usually consists of extracting desired properties to be reproduced through observation, and their characterisation using tools from more traditional experimental sciences. In this way, novel hypotheses may be developed, and empirical data may be analysed from the perspective of the simulation model.
In creating models of action selection (and of other models of biological functioning), there are four important questions which need to be addressed and which should also be bourne in mind during development (quote from paper): "...is the model sufficiently constrained by biological data that its functioning can capture interesting properties of the natural system of interest? Do manipulations of the model, intended to mirror scientific procedures or observed natural processes, result in similar outcomes to those seen in real life? Does the model make predictions? Is the model more complex than it needs to be in order to describe a phenomenon, or is it too simple to engage with empirical data?" Concerning this last question, there is then a trade-off between simplicity for the purposes of analysis and adequate complexity for a sufficient model of the process(es) in question, neither extreme of which is suitable.
The introductory paper (by Prescott, Bryson and Seth) summarises the eight main areas covered by the special issue contributors (optimality of action selection, cortical-basal ganglia substrates, behavioural sequencing, subcortical substrates, disorders, perceptual selection, units of selection, and action selection in social contexts) and provides a discussion of modelling strategies and techniques in general. I hope to summarise a few of these papers in the coming weeks (particularly Botvinicks paper on a model of Fusters 'hierarchies').
Contents of special issue, here. Unfortunately, all of the papers are available by subscription only.
- Introduction. Modelling natural action selection TJ Prescott, JJ Bryson and AK Seth
- Do we expect natural selection to produce rational behaviour? AI Houston, JM McNamara and MD Steer
- The ecology of action selection: insights from artificial life AK Seth
- Compromise strategies for action selection FL Crabbe
- Action selection and refinement in subcortical loops through basal ganglia and cerebellum JC Houk, C Bastianen, D Fansler, A Fishbach, D Fraser, PJ Reber, SA Roy and LS Simo
- Cortical mechanisms of action selection: the affordance competition hypothesis P Cisek
- Towards an executive without a homunculus: computational models of the prefrontal cortex/basal ganglia system TE Hazy, MJ Frank and RC O'Reilly
- Multilevel structure in behaviour and in the brain: a model of Fuster's hierarchy MM Botvinick
- Is there a brainstem substrate for action selection? MD Humphries, K Gurney, and TJ Prescott
- Understanding decision-making deficits in neurological conditions: insights from models of natural action selection MJ Frank, A Scheres and SJ Sherman
- Extending a biologically inspired model of choice: multi-alternatives, nonlinearity and value-based multidimensional choice R Bogacz, M Usher, J Zhang and JL McClelland
- Biologically constrained action selection improves cognitive control in a model of the Stroop task T Stafford and KN Gurney
- Agent-based modelling as scientific method: a case study analysing primate social behaviour JJ Bryson, Y Ando and H Lehmann
- An agent-based model of group decision making in baboons WI Sellers, RA Hill and BS Logan
- Spatial models of political competition with endogenous political parties M Laver and M Schilperoord
Philosophical Transactions of the Royal Society London B
September 2007
A special issue containing fourteen papers on various aspects of modelling action selection in animals and humans. There are multiple methods in the study of biological action selection ("of deciding 'what to do next'"), each approaching the problem from different points of view: be it ethology or psychology studying the biological systems, or artificial intelligence or artificial life attempting to build artefacts based on the biological principles. These differing approaches may be characterised by distinguishing between the analytical and synthetic methods in the behavioural and brain sciences, as proposed by Braitenberg.
The analytical method seeks to describe transitions in behaviour (and to explain why they occur in any given context), either functionally through reference to some concept of utility, or mechanistically through reference to underlying neural systems. It is at the overlap between these two approaches that modelling (the "synthetic" approach - the creation of artificial systems which behave as natural ones) has an increasing influence: "what would it take to build a system that acts in this way?" It is not only formal mathematical models which are of interest, but also, and in cooperation, simulations for which mathematical solutions are intractable or unknown. This usually consists of extracting desired properties to be reproduced through observation, and their characterisation using tools from more traditional experimental sciences. In this way, novel hypotheses may be developed, and empirical data may be analysed from the perspective of the simulation model.
In creating models of action selection (and of other models of biological functioning), there are four important questions which need to be addressed and which should also be bourne in mind during development (quote from paper): "...is the model sufficiently constrained by biological data that its functioning can capture interesting properties of the natural system of interest? Do manipulations of the model, intended to mirror scientific procedures or observed natural processes, result in similar outcomes to those seen in real life? Does the model make predictions? Is the model more complex than it needs to be in order to describe a phenomenon, or is it too simple to engage with empirical data?" Concerning this last question, there is then a trade-off between simplicity for the purposes of analysis and adequate complexity for a sufficient model of the process(es) in question, neither extreme of which is suitable.
The introductory paper (by Prescott, Bryson and Seth) summarises the eight main areas covered by the special issue contributors (optimality of action selection, cortical-basal ganglia substrates, behavioural sequencing, subcortical substrates, disorders, perceptual selection, units of selection, and action selection in social contexts) and provides a discussion of modelling strategies and techniques in general. I hope to summarise a few of these papers in the coming weeks (particularly Botvinicks paper on a model of Fusters 'hierarchies').
Contents of special issue, here. Unfortunately, all of the papers are available by subscription only.
- Introduction. Modelling natural action selection TJ Prescott, JJ Bryson and AK Seth
- Do we expect natural selection to produce rational behaviour? AI Houston, JM McNamara and MD Steer
- The ecology of action selection: insights from artificial life AK Seth
- Compromise strategies for action selection FL Crabbe
- Action selection and refinement in subcortical loops through basal ganglia and cerebellum JC Houk, C Bastianen, D Fansler, A Fishbach, D Fraser, PJ Reber, SA Roy and LS Simo
- Cortical mechanisms of action selection: the affordance competition hypothesis P Cisek
- Towards an executive without a homunculus: computational models of the prefrontal cortex/basal ganglia system TE Hazy, MJ Frank and RC O'Reilly
- Multilevel structure in behaviour and in the brain: a model of Fuster's hierarchy MM Botvinick
- Is there a brainstem substrate for action selection? MD Humphries, K Gurney, and TJ Prescott
- Understanding decision-making deficits in neurological conditions: insights from models of natural action selection MJ Frank, A Scheres and SJ Sherman
- Extending a biologically inspired model of choice: multi-alternatives, nonlinearity and value-based multidimensional choice R Bogacz, M Usher, J Zhang and JL McClelland
- Biologically constrained action selection improves cognitive control in a model of the Stroop task T Stafford and KN Gurney
- Agent-based modelling as scientific method: a case study analysing primate social behaviour JJ Bryson, Y Ando and H Lehmann
- An agent-based model of group decision making in baboons WI Sellers, RA Hill and BS Logan
- Spatial models of political competition with endogenous political parties M Laver and M Schilperoord
10,000
A week or two ago now (I don't know exactly, since I've not been about much to check), this little blog received its 10,000th visitor - which is around 9,900 more than I was expecting when I started just over a year ago, since it was intended as a repository of my thoughts and notes. I hope that there has been something of interest and utility, and I would like to use this opportunity to thank all those who have linked here or left comments - many have led me in directions of research both interesting and useful to my own work.
Paul :-)
Paul :-)
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