44,282 research outputs found
Exact sampling of self-avoiding paths via discrete Schramm-Loewner evolution
We present an algorithm, based on the iteration of conformal maps, that
produces independent samples of self-avoiding paths in the plane. It is a
discrete process approximating radial Schramm-Loewner evolution growing to
infinity. We focus on the problem of reproducing the parametrization
corresponding to that of lattice models, namely self-avoiding walks on the
lattice, and we propose a strategy that gives rise to discrete paths where
consecutive points lie an approximately constant distance apart from each
other. This new method allows us to tackle two non-trivial features of
self-avoiding walks that critically depend on the parametrization: the
asphericity of a portion of chain and the correction-to-scaling exponent.Comment: 18 pages, 4 figures. Some sections rewritten (including title and
abstract), numerical results added, references added. Accepted for
publication in J. Stat. Phy
Decoherence in Discrete Quantum Walks
We present an introduction to coined quantum walks on regular graphs, which
have been developed in the past few years as an alternative to quantum Fourier
transforms for underpinning algorithms for quantum computation. We then
describe our results on the effects of decoherence on these quantum walks on a
line, cycle and hypercube. We find high sensitivity to decoherence, increasing
with the number of steps in the walk, as the particle is becoming more
delocalised with each step. However, the effect of a small amount of
decoherence can be to enhance the properties of the quantum walk that are
desirable for the development of quantum algorithms, such as fast mixing times
to uniform distributions.Comment: 15 pages, Springer LNP latex style, submitted to Proceedings of DICE
200
A model for quantum queue
We consider an extension of Discrete Time Markov Chain queueing model to the
quantum domain by use of Discrete Time Quantum Markov Chain. We introduce
methods for numerical analysis of such models. Using this tools we show that
quantum model behaves fundamentally differently from the classical one.Comment: 14 pages, 7 figure
The effect of using labelled alternatives in stated choice experiments: an exploration focusing on farmland walking trails in Ireland
Discrete choice experiment data aimed at eliciting the demand for recreational walking trails on farmland in Ireland is used to explore whether some respondents reach their choices solely on the basis of the alternativeâs label. To investigate this type of processing strategy, the paper exploits a discrete mixtures approach which encompasses random parameters for the attributes. We find evidence that respondents employ different processing strategies for different alternatives and differences in processing emerge between rural and urban based respondents. Results highlight that model fit and policy conclusions are sensitive to assumptions related to processing strategies among respondentsDiscrete choice experiments, processing strategies, discrete mixtures, rural and urban comparison, outdoor recreation, welfare estimates, Land Economics/Use,
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