19,350 research outputs found
Psychophysical identity and free energy
An approach to implementing variational Bayesian inference in biological
systems is considered, under which the thermodynamic free energy of a system
directly encodes its variational free energy. In the case of the brain, this
assumption places constraints on the neuronal encoding of generative and
recognition densities, in particular requiring a stochastic population code.
The resulting relationship between thermodynamic and variational free energies
is prefigured in mind-brain identity theses in philosophy and in the Gestalt
hypothesis of psychophysical isomorphism.Comment: 22 pages; published as a research article on 8/5/2020 in Journal of
the Royal Society Interfac
On the distribution of stellar-sized black hole spins
Black hole spin will have a large impact on searches for gravitational waves
with advanced detectors. While only a few stellar mass black hole spins have
been measured using X-ray techniques, gravitational wave detectors have the
capacity to greatly increase the statistics of black hole spin measurements. We
show what we might learn from these measurements and how the black hole spin
values are influenced by their formation channels.Comment: 4 pages, 2 figures, pre-GW150914 detection, refereed and accepted
contribution to proceedings of 11th Edoardo Amaldi Conference on
Gravitational Waves, June 2015, Gwangju, Kore
The 'what' and 'how' of learning in design, invited paper
Previous experiences hold a wealth of knowledge which we often take for granted and use unknowingly through our every day working lives. In design, those experiences can play a crucial role in the success or failure of a design project, having a great deal of influence on the quality, cost and development time of a product. But how can we empower computer based design systems to acquire this knowledge? How would we use such systems to support design? This paper outlines some of the work which has been carried out in applying and developing Machine Learning techniques to support the design activity; particularly in utilising previous designs and learning the design process
Coulomb drag in quantum circuits
We study drag effect in a system of two electrically isolated quantum point
contacts (QPC), coupled by Coulomb interactions. Drag current exhibits maxima
as a function of QPC gate voltages when the latter are tuned to the transitions
between quantized conductance plateaus. In the linear regime this behavior is
due to enhanced electron-hole asymmetry near an opening of a new conductance
channel. In the non-linear regime the drag current is proportional to the shot
noise of the driving circuit, suggesting that the Coulomb drag experiments may
be a convenient way to measure the quantum shot noise. Remarkably, the
transition to the non-linear regime may occur at driving voltages substantially
smaller than the temperature.Comment: 6 pages, 2 figure
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