20,285 research outputs found

### Using a cognitive prosthesis to assist foodservice managerial decision-making

The artificial intelligence community has been notably unsuccessful in producing intelligent agents that think for themselves. However, there is an obvious need for increased information processing power in real life situations. An example of this can be witnessed in the training of a foodservice manager, who is expected to solve a wide variety of complex problems on a daily basis. This article explores the possibility of creating an intelligence aid, rather than an intelligence agent, to assist novice foodservice managers in making decisions that are congruent with a subject matter expert\u27s decision schema

### Curvature Dependent Diffusion Flow on Surface with Thickness

Particle diffusion in a two dimensional curved surface embedded in $R_3$ is
considered. In addition to the usual diffusion flow, we find a new flow with an
explicit curvature dependence. New diffusion equation is obtained in $\epsilon$
(thickness of surface) expansion. As an example, the surface of elliptic
cylinder is considered, and curvature dependent diffusion coefficient is
calculated.Comment: 8 pages, 8 figures, Late

### Effects of antibodies against dynein and tubulin on the stiffness of flagellar axonemes

Antidynein antibodies, previously shown to inhibit flagellar oscillation and active sliding of axonemal microtubules, increase the bending resistance of axonemes measured under relaxing conditions, but not the bending resistance of axonemes measured under rigor conditions. These observations suggest that antidynein antibodies can stabilize rigor cross-bridges between outer-doublet microtubules, by interfering with ATP-induced cross-bridge detachment. Stabilization of a small number of cross-bridge appears to be sufficient to cause substantial inhibition of the frequency of flagellar oscillation. Antitubulin antibodies, previously shown to inhibit flagellar oscillation without inhibiting active sliding of axonemal microtubules, do not increase the static bending resistance of axonemes. However, we observed a viscoelastic effect, corresponding to a large increase in the immediate bending resistance. This immediate bending resistance increase may be sufficient to explain inhibition of flagellar oscillation; but several alternative explanations cannot yet be excluded

### The Yang-Mills gradient flow and SU(3) gauge theory with 12 massless fundamental fermions in a colour-twisted box

We perform the step-scaling investigation of the running coupling constant,
using the gradient-flow scheme, in SU(3) gauge theory with twelve massless
fermions in the fundamental representation. The Wilson plaquette gauge action
and massless unimproved staggered fermions are used in the simulations. Our
lattice data are prepared at high accuracy, such that the statistical error for
the renormalised coupling, g_GF, is at the subpercentage level. To investigate
the reliability of the continuum extrapolation, we employ two different lattice
discretisations to obtain g_GF. For our simulation setting, the corresponding
gauge-field averaging radius in the gradient flow has to be almost half of the
lattice size, in order to have this extrapolation under control. We can
determine the renormalisation group evolution of the coupling up to g^2_GF ~ 6,
before the onset of the bulk phase structure. In this infrared regime, the
running of the coupling is significantly slower than the two-loop perturbative
prediction, although we cannot draw definite conclusion regarding possible
infrared conformality of this theory. Furthermore, we comment on the issue
regarding the continuum extrapolation near an infrared fixed point. In addition
to adopting the fit ansatz a'la Symanzik for performing this task, we discuss a
possible alternative procedure inspired by properties derived from low-energy
scale invariance at strong coupling. Based on this procedure, we propose a
finite-size scaling method for the renormalised coupling as a means to search
for infrared fixed point. Using this method, it can be shown that the behaviour
of the theory around g^2_GF ~ 6 is still not governed by possible infrared
conformality.Comment: 24 pages, 6 figures; Published version; Appendix A added for
tabulating data; One reference included; Typos correcte

### Lattice study of infrared behaviour in SU(3) gauge theory with twelve massless flavours

We present details of a lattice study of infrared behaviour in SU(3) gauge
theory with twelve massless fermions in the fundamental representation. Using
the step-scaling method, we compute the coupling constant in this theory over a
large range of scale. The renormalisation scheme in this work is defined by the
ratio of Polyakov loops in the directions with different boundary conditions.
We closely examine systematic effects, and find that they are dominated by
errors arising from the continuum extrapolation. Our investigation suggests
that SU(3) gauge theory with twelve flavours contains an infrared fixed point.Comment: 29 pages, 15 figures, 4 tables. Minor revision. Published versio

### Excitons and biexcitons in symmetric electron-hole bilayers

Symmetric electron-hole bilayer systems have been studied at zero temperature
using the diffusion quantum Monte Carlo method. A flexible trial wave function
is used that can describe fluid, excitonic and biexcitonic phases. We calculate
condensate fractions and pair correlation functions for a large number of
densities rs and layer separations d. At small d we find a one-component fluid
phase, an excitonic fluid phase, and a biexcitonic fluid phase, and the
transitions among them appear to be continuous. At d = 0, excitons appear to
survive down to about rs = 0.5 a.u., and biexcitons form at rs > 2.5 a.u.Comment: 5 pages, 4 figure

### Quantum dynamics of non-relativistic particles and isometric embeddings

It is considered, in the framework of constrained systems, the quantum
dynamics of non-relativistic particles moving on a d-dimensional Riemannian
manifold M isometrically embedded in $R^{d+n}$. This generalizes recent
investigations where M has been assumed to be a hypersurface of $R^{d+1}$. We
show, contrary to recent claims, that constrained systems theory does not
contribute to the elimination of the ambiguities present in the canonical and
path integral formulations of the problem. These discrepancies with recent
works are discussed.Comment: Revtex, 14 page

### Polymers in Curved Boxes

We apply results derived in other contexts for the spectrum of the Laplace
operator in curved geometries to the study of an ideal polymer chain confined
to a spherical annulus in arbitrary space dimension D and conclude that the
free energy compared to its value for an uncurved box of the same thickness and
volume, is lower when $D < 3$, stays the same when $D = 3$, and is higher when
\mbox{$D > 3$}. Thus confining an ideal polymer chain to a cylindrical shell,
lowers the effective bending elasticity of the walls, and might induce
spontaneous symmetry breaking, i.e. bending. (Actually, the above mentioned
results show that {\em {any}} shell in $D = 3$ induces this effect, except for
a spherical shell). We compute the contribution of this effect to the bending
rigidities in the Helfrich free energy expression.Comment: 20 pages RevTeX, epsf; 4 figures; submitted to Macromoledule

### Leaf area index and topographical effects on turburlent diffusion in a deciduous forest

In order to investigate turbulent diffusion in a deciduous forest canopy, wind velocity
measurements were conducted from late autumn of 2009 to early spring of 2010, using an observation tower
20 m in height located in the campus of Kanazawa University. Four sonic anemometers mounted on the
tower recorded the average wind velocities and temperatures, as well as their fluctuations, at four different
heights simultaneously. Two different types of data sets were selected, in which the wind velocities, wind
bearings and atmospheric stabilities were all similar, but the Leaf Area Indexes (LAI's) were different.
Vertical profiles of average wind velocities were found to have an approximately exponential profile in each
case. The characteristic length scales of turbulence were evaluated by both von Karman's method and the
integral time scale deduced from the autocorrelation from time-series analyses. Both methods produced
comparable values of eddy diffusivity for the cases with some foliage during late autumn, but some
discrepancy in the upper canopy layer was observed when the trees did not have their leaves in early spring.
It was also found that the eddy diffusivities generally take greater values at higher positions, where the wind
speeds are large. Anisotropy of eddy diffusivities between the vertical and horizontal components was also
observed, particularly in the cases when the canopy does not have leaves, when the horizontal eddy
diffusivities are generally larger than the vertical ones. On the other hand, the anisotropy is less visible when
the trees have some foliage during autumn. The effects of topography on the turbulent diffusion were also
investigated, including evaluation of the non-zero time-averaged vertical wind velocities. The results show
that the effects are marginal for both cases, and can be neglected as far as diffusion in the canopy is
concerned

### Operation of solar cell arrays in dilute streaming plasmas

Operation of solar cell arrays in dilute streaming plasma

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