11,469 research outputs found
An Intelligent Advisor for City Traffic Policies
Nowadays, city streets are populated not only by private vehicles but also by public transport, fleets of workers, and deliveries. Since
each vehicle class has a maximum cargo capacity, we study in this article how authorities could improve the road traffic by endorsing long term policies to change the different vehicle proportions: sedans, minivans, full size vans, trucks, and motorbikes, without losing the ability of moving cargo throughout the city. We have performed our study in a realistic scenario (map, road traffic characteristics, and number of vehicles) of the city of Malaga and captured the many details into the SUMO microsimulator. After analyzing the relationship between travel times, emissions, and fuel consumption, we have defined a multiobjective optimization problem to be solved, so as to minimize these city metrics. Our results provide a scientific evidence that we can improve the delivery of goods
in the city by reducing the number of heavy duty vehicles and fostering the use of vans instead.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech.
This research has been partially funded by the Spanish MINECO and FEDER projects TIN2014-57341-R, TIN2016-81766-REDT, and
TIN2017-88213-R. University of Malaga, Andalucia TECH. Daniel H. Stolfi is supported by a FPU grant (FPU13/00954) from the Spanish MECD. Christian Cintrano is supported by a FPI grant (BES-2015-074805) from Spanish MINECO
Top quark pair production via polarized and unpolarized photons in Supersymmetric QCD
QCD corrections to top quark pair production via fusion of both polarized and
unpolarized photons are calculated in Supersymmetric Model. The corrections are
found to be sizable. The dependence of the corrections on the masses of the
supersymmetric particles is also investigated. Furthermore, we studied CP
asymmetry effects arising from the complex couplings in the MSSM. The CP
violating parameter can reach for favorable parameter values.Comment: 26 pages, LaTex, including 12 figures in 12 eps files. submitted to
Phys. Rev.
Nonequilibrium relaxation of the two-dimensional Ising model: Series-expansion and Monte Carlo studies
We study the critical relaxation of the two-dimensional Ising model from a
fully ordered configuration by series expansion in time t and by Monte Carlo
simulation. Both the magnetization (m) and energy series are obtained up to
12-th order. An accurate estimate from series analysis for the dynamical
critical exponent z is difficult but compatible with 2.2. We also use Monte
Carlo simulation to determine an effective exponent, z_eff(t) = - {1/8} d ln t
/d ln m, directly from a ratio of three-spin correlation to m. Extrapolation to
t = infinity leads to an estimate z = 2.169 +/- 0.003.Comment: 9 pages including 2 figure
Advances in differential diagnosis and management of growth hormone deficiency in children
Growth hormone (GH) deficiency (GHD) in children is defined as impaired production of GH by the pituitary gland that results in growth failure. This disease might be congenital or acquired, and occurs in isolation or in the setting of multiple pituitary hormone deficiency. Isolated GHD has an estimated prevalence of 1 patient per 4000–10,000 live births and can be due to multiple causes, some of which are yet to be determined. Establishing the correct diagnosis remains key in children with short stature, as initiating treatment with recombinant human GH can help them attain their genetically determined adult height. During the past two decades, our understanding of the benefits of continuing GH therapy throughout the transition period from childhood to adulthood has increased. Improvements in transitional care will help alleviate the consequent physical and psychological problems that can arise from adult GHD, although the consequences of a lack of hormone replacement are less severe in adults than in children. In this Review, we discuss the differential diagnosis in children with GHD, including details of clinical presentation, neuroimaging and genetic testing. Furthermore, we highlight advances and issues in the management of GHD, including details of transitional care
Controlling light-with-light without nonlinearity
According to Huygens' superposition principle, light beams traveling in a
linear medium will pass though one another without mutual disturbance. Indeed,
it is widely held that controlling light signals with light requires intense
laser fields to facilitate beam interactions in nonlinear media, where the
superposition principle can be broken. We demonstrate here that two coherent
beams of light of arbitrarily low intensity can interact on a metamaterial
layer of nanoscale thickness in such a way that one beam modulates the
intensity of the other. We show that the interference of beams can eliminate
the plasmonic Joule losses of light energy in the metamaterial or, in contrast,
can lead to almost total absorbtion of light. Applications of this phenomenon
may lie in ultrafast all-optical pulse-recovery devices, coherence filters and
THz-bandwidth light-by-light modulators
Low energy properties of M-state tunneling systems in metals: New candidates for non-Fermi-liquid systems
We construct a generalized multiplicative renormalization group
transformation to study the low energy dynamics of a heavy particle tunneling
among different positions and interacting with independent conduction
electron channels. Using a -expansion we show that this M-level scales
towards a fixed point equivalent to the channel
Coqblin-Schrieffer model. Solving numerically the scaling equations we find
that a realistic M-level system scales close to this fixed point (FP) and its
Kondo temperature is in the experimentally observable range .Comment: 11 Latex pages, to appear in Phys. Rev. Lett, Figures available from
the author by reques
The underscreened Kondo effect: a two S=1 impurity model
The underscreened Kondo effect is studied within a model of two impurities
S=1 interacting with the conduction band and via an interimpurity coupling
. Using a mean-field treatment of the bosonized
Hamiltonian, we show that there is no phase transition, but a continuous
cross-over versus K from a non Kondo behaviour to an underscreened Kondo one.
For a small antiferromagnetic coupling (K>0), a completely asymmetric situation
is obtained with one s= component strongly screened by the Kondo effect
and the other one almost free to yield indirect magnetism, which shows finally
a possible coexistence between a RKKY interaction and a local Kondo effect, as
observed in Uranium compounds such as .Comment: 27 pages, RevTeX, to be published in PR
The Growth of Black Holes and Their Host Spheroids in (Sub)mm-loud QSOs at High Redshift
We study the growth of black holes and stellar population in spheroids at
high redshift using several (sub)mm-loud QSO samples. Applying the same
criteria established in an earlier work, we find that, similar to IR QSOs at
low redshift, the far-infrared emission of these (sub)mm-loud QSOs mainly
originates from dust heated by starbursts. By combining low-z IR QSOs and
high-z (sub)mm-loud QSOs, we find a trend that the star formation rate
(\Mstardot) increases with the accretion rate (\Mdot). We compare the
values of \Mstardot/\Mdot for submm emitting galaxies (SMGs), far-infrared
ultraluminous/hyperluminous QSOs and typical QSOs, and construct a likely
evolution scenario for these objects. The (sub)mm-loud QSO transition phase has
both high \Mdot and \Mstardot and hence is important for establishing the
correlation between the masses of black holes and spheroids.Comment: 19 pages,3 figures,submitted to Chin. J. Astron. Astrophys. This
paper was first prepared for publication on August 10th, 200
On The Multichannel Kondo Model"
A detailed and comprehensive study of the one-impurity multichannel Kondo
model is presented. In the limit of a large number of conduction electron
channels , the low energy fixed point is accessible to a
renormalization group improved perturbative expansion in . This
straightforward approach enables us to examine the scaling, thermodynamics and
dynamical response functions in great detail and make clear the following
features: i) the criticality of the fixed point; ii) the universal non-integer
degeneracy; iii) that the compensating spin cloud has the spatial extent of the
order of one lattice spacing.Comment: 28 pages, REVTEX 2.0. Submitted to J. Phys.: Cond. Mat. Reference
.bbl file is appended at the end. 5 figures in postscript files can be
obtained at [email protected]. The filename is gan.figures.tar.z and
it's compressed. You can uncompress it by using commands: "uncompress
gan.figures.tar.z" and "tar xvf gan.figures.tar". UBC Preprin
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