3,294 research outputs found
Entanglement and quantum combinatorial designs
We introduce several classes of quantum combinatorial designs, namely quantum
Latin squares, cubes, hypercubes and a notion of orthogonality between them. A
further introduced notion, quantum orthogonal arrays, generalizes all previous
classes of designs. We show that mutually orthogonal quantum Latin arrangements
can be entangled in the same way than quantum states are entangled.
Furthermore, we show that such designs naturally define a remarkable class of
genuinely multipartite highly entangled states called -uniform, i.e.
multipartite pure states such that every reduction to parties is maximally
mixed. We derive infinitely many classes of mutually orthogonal quantum Latin
arrangements and quantum orthogonal arrays having an arbitrary large number of
columns. The corresponding multipartite -uniform states exhibit a high
persistency of entanglement, which makes them ideal candidates to develop
multipartite quantum information protocols.Comment: 14 pages, 3 figures. Comments are very welcome
A Qualitative Exploration of Emerging Adults’ and Parents’ Perspectives on Communicating Adulthood Status
In this study the authors examine parent - child communication in Emerging Adulthood. Thirty - seven college students and one or both of their parents completed written questionnaires assessing whether the parent had verbally communicated or did some action to acknowledge the Emerging Adult’s maturity. Communication about changes in the parent - child relationship, as well as the Emerging Adult’s decision - making abilities, obligations to the family, and financial responsibilities were also assessed. The responses to the open ended questions were qualitatively analyzed using grounded theory. The findings indicated that the Emerging Adults’ and parents’ responses were very similar, and the overwhelming majority reported that there had indeed been an acknowledgment from the parents to indicate Emerging Adulthood status, although this was not always verbally communicated; sometimes it was indicated through the parents’ behavior.
Fast spatial simulation of extreme high-resolution radar precipitation data using INLA
We develop a methodology for modelling and simulating high-dimensional
spatial precipitation extremes, using a combination of the spatial conditional
extremes model, latent Gaussian models and integrated nested Laplace
approximations (INLA). The spatial conditional extremes model requires data
with Laplace marginal distributions, but precipitation distributions contain
point masses at zero that complicate necessary standardisation procedures. We
propose to model conditional extremes of nonzero precipitation only, while
separately modelling precipitation occurrences. The two models are then
combined to create a complete model for extreme precipitation. Nonzero
precipitation marginals are modelled using a combination of latent Gaussian
models with gamma and generalised Pareto likelihoods. Four different models for
precipitation occurrence are investigated. New empirical diagnostics and
parametric models are developed for describing components of the spatial
conditional extremes model. We apply our framework to simulate spatial
precipitation extremes over a water catchment in Central Norway, using
high-density radar data. Inference on a 6000-dimensional data set is performed
within hours, and the simulated data capture the main trends of the observed
data well
An Efficient Workflow for Modelling High-Dimensional Spatial Extremes
A successful model for high-dimensional spatial extremes should, in
principle, be able to describe both weakening extremal dependence at increasing
levels and changes in the type of extremal dependence class as a function of
the distance between locations. Furthermore, the model should allow for
computationally tractable inference using inference methods that efficiently
extract information from data and that are robust to model misspecification. In
this paper, we demonstrate how to fulfil all these requirements by developing a
comprehensive methodological workflow for efficient Bayesian modelling of
high-dimensional spatial extremes using the spatial conditional extremes model
while performing fast inference with R-INLA. We then propose a post hoc
adjustment method that results in more robust inference by properly accounting
for possible model misspecification. The developed methodology is applied for
modelling extreme hourly precipitation from high-resolution radar data in
Norway. Inference is computationally efficient, and the resulting model fit
successfully captures the main trends in the extremal dependence structure of
the data. Robustifying the model fit by adjusting for possible misspecification
further improves model performance
Feynman graphs and the large dimensional limit of multipartite entanglement
We are interested in the properties of multipartite entanglement of a system
composed by -level parties (qudits).
Focussing our attention on pure states we want to tackle the problem of the
maximization of the entanglement for such systems. In particular we effort the
problem trying to minimize the purity of the system. It has been shown that not
for all systems this function can reach its lower bound, however it can be
proved that for all values of a can always be found such that the lower
bound can be reached.
In this paper we examine the high-temperature expansion of the distribution
function of the bipartite purity over all balanced bipartition considering its
optimization problem as a problem of statistical mechanics. In particular we
prove that the series characterizing the expansion converges and we analyze the
behavior of each term of the series as .Comment: 29 pages, 11 figure
Changes in behavioural response of Mediterranean Seabass (Dicenthratus labrax L.) under different feeding distributions
Captive-induced behavioural deviations may
involve many aspects of fish behaviour such as
swimming activity and enhancement of individual
aggressiveness. We studied seabass
(Dicentrarchus labrax) behaviour as a function
of manual and automatic feeding distribution
modes. Under manual mode, the food is distributed
over an extended area for a longer period,
and its precise location is not always predictable,
while with pneumatic automatic feeders,
fish receive the same amount of resource,
which is concentrated in the same surface area
over a shorter period. We compared seabass
behaviour under automatic and manual conditions
collecting video image recordings before,
during, and after feeding distribution, in the
morning and in afternoon, on two different
days, and analysing data within independent
sessions of measurements. Feeding modes significantly
affected swimming behaviour: automatically-
fed fish were characterised by vertical
movements through the water column (towards
the surface and bottom) and by horizontal
swimming. Manually-fed fish were instead
characterised by sharp direction changes during
their swimming, mostly towards the surface.
Feeding distribution induced changes in
collision frequency and elicited aggressive
behaviour. In particular, agonistic behaviour
(i.e. a fish attacks another fish) was almost
exclusively recorded during the feeding under
automatic distribution, whereas it was constantly
expressed during all the distribution
phases under manual mod
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