2,839 research outputs found
The next generation demand network in quick response systems:Intelligent products, packet switching and dynamic information
Nanoscale temperature measurements using non-equilibrium Brownian dynamics of a levitated nanosphere
Einstein realised that the fluctuations of a Brownian particle can be used to
ascertain properties of its environment. A large number of experiments have
since exploited the Brownian motion of colloidal particles for studies of
dissipative processes, providing insight into soft matter physics, and leading
to applications from energy harvesting to medical imaging. Here we use
optically levitated nanospheres that are heated to investigate the
non-equilibrium properties of the gas surrounding them. Analysing the sphere's
Brownian motion allows us to determine the temperature of the centre-of-mass
motion of the sphere, its surface temperature and the heated gas temperature in
two spatial dimensions. We observe asymmetric heating of the sphere and gas,
with temperatures reaching the melting point of the material. This method
offers new opportunities for accurate temperature measurements with spatial
resolution on the nanoscale, and a new means for testing non-equilibrium
thermodynamicsComment: 5 pages, 4 figures, supplementary material available upon reques
Observation of Scaling Violations in Scaled Momentum Distributions at HERA
Charged particle production has been measured in deep inelastic scattering
(DIS) events over a large range of and using the ZEUS detector. The
evolution of the scaled momentum, , with in the range 10 to 1280
, has been investigated in the current fragmentation region of the Breit
frame. The results show clear evidence, in a single experiment, for scaling
violations in scaled momenta as a function of .Comment: 21 pages including 4 figures, to be published in Physics Letters B.
Two references adde
Optimal control of a dengue epidemic model with vaccination
We present a SIR+ASI epidemic model to describe the interaction between human
and dengue fever mosquito populations. A control strategy in the form of
vaccination, to decrease the number of infected individuals, is used. An
optimal control approach is applied in order to find the best way to fight the
disease.Comment: This is a preprint of a paper accepted for presentation at ICNAAM
2011, Halkidiki, Greece, 19-25 September 2011, and to appear in AIP
Conference Proceedings, volume 138
Intense violet–blue emission and paramagnetism of nanocrystalline Gd3+ doped ZnO ceramics
Nanocrystalline Zn1-xGdxO (x = 0, 0.02, 0.04, 0.06, and 0.08) ceramics were synthesized by ball milling and subsequent solid-state reaction. The transmission electron microscopy (TEM) micrograph of as synthesized samples revealed the formation of crystallites with an average diameter of 60 nm, and the selected area electron diffraction (SAED) pattern confirmed the formation of wurtzite structure. A red shift in the band gap was observed with increasing Gd3+ concentration. The photoluminescence of nanocrystalline Gd3+ doped ZnO exhibited a strong violet–blue emission. Concentration dependence of the emission intensity of Gd3+ in ZnO was studied, and the critical concentration was found to be 4 mol% of Gd3+. The Gd3+ doped ZnO exhibited paramagnetic behavior at room temperature, and the magnetic moment increased with Gd3+ concentration
Modeling and Optimal Control Applied to a Vector Borne Disease
A model with six mutually-exclusive compartments related to Dengue disease is
presented. In this model there are three vector control tools: insecticides
(larvicide and adulticide) and mechanical control. The problem is studied using
an Optimal Control (OC) approach. The human data for the model is based on the
Cape Verde Dengue outbreak. Some control measures are simulated and their
consequences analyzed
Relative Riemann-Hilbert correspondence in dimension one
We prove that, on a Riemann surface, the functor constructed
in a previous work as a right quasi-inverse of the solution functor from the
bounded derived category of regular relative holonomic modules to that of
relative constructible complexes satisfies the left quasi-inverse property in a
generic sense.Comment: 10 pages. V2: revised version, some mistake corrected, improvement of
the presentation. V3: final version to be publishe
Foraging for foundations in decision neuroscience: insights from ethology
Modern decision neuroscience offers a powerful and broad account of human behaviour using computational techniques that link psychological and neuroscientific approaches to the ways that individuals can generate near-optimal choices in complex controlled environments. However, until recently, relatively little attention has been paid to the extent to which the structure of experimental environments relates to natural scenarios, and the survival problems that individuals have evolved to solve. This situation not only risks leaving decision-theoretic accounts ungrounded but also makes various aspects of the solutions, such as hard-wired or Pavlovian policies, difficult to interpret in the natural world. Here, we suggest importing concepts, paradigms and approaches from the fields of ethology and behavioural ecology, which concentrate on the contextual and functional correlates of decisions made about foraging and escape and address these lacunae
Insecticide control in a Dengue epidemics model
A model for the transmission of dengue disease is presented. It consists of
eight mutually-exclusive compartments representing the human and vector
dynamics. It also includes a control parameter (insecticide) in order to fight
the mosquitoes. The main goal of this work is to investigate the best way to
apply the control in order to effectively reduce the number of infected humans
and mosquitoes. A case study, using data of the outbreak that occurred in 2009
in Cape Verde, is presented.Comment: Accepted 28/07/2010 in the special session "Numerical Optimization"
of the 8th International Conference of Numerical Analysis and Applied
Mathematics (ICNAAM 2010), Rhodes, Greece, 19-25 September 201
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