9,939 research outputs found
Power-law statistics and stellar rotational velocities in the Pleiades
In this paper we will show that, the non-gaussian statistics framework based
on the Kaniadakis statistics is more appropriate to fit the observed
distributions of projected rotational velocity measurements of stars in the
Pleiades open cluster. To this end, we compare the results from the
and -distributions with the Maxwellian.Comment: 13 pages, 3 figure
Compactly Supported Wavelets Derived From Legendre Polynomials: Spherical Harmonic Wavelets
A new family of wavelets is introduced, which is associated with Legendre
polynomials. These wavelets, termed spherical harmonic or Legendre wavelets,
possess compact support. The method for the wavelet construction is derived
from the association of ordinary second order differential equations with
multiresolution filters. The low-pass filter associated with Legendre
multiresolution analysis is a linear phase finite impulse response filter
(FIR).Comment: 6 pages, 6 figures, 1 table In: Computational Methods in Circuits and
Systems Applications, WSEAS press, pp.211-215, 2003. ISBN: 960-8052-88-
RDSim: A fast, accurate and flexible framework for the simulation of the radio emission and detection of downgoing air showers
RDSim is a fast, accurate and flexible framework for the simulation of the
radio emission of downgoing air showers and its detection by an arbitrary
array, including showers initiated by neutrino interactions or tau-lepton
decays. RDSim was build around speed and is based on simple and fast, yet still
accurate, toymodel-like approaches. It models the radio emission using a
superposition emission model that disentangles the Askaryan and geomagnetic
components of the shower radio emission. It uses full ZHAireS simulations as an
input to estimate the electric field at any position on the ground. A single
input simulation can be scaled in energy and rotated in azimuth, taking into
account all relevant effects. This makes it possible to simulate a huge number
of geometries and energies using just a few ZHAireS input simulations. RDSim
takes into account the main characteristics of the detector, such as trigger
setups, thresholds and antenna patterns. To accommodate arrays that use
particle detectors for triggering, such as the Auger RD extension, it also
features a second toymodel to estimate the muon density at ground level and
perform simple particle trigger simulations. Owing to the large statistics made
possible by its speed, it can be used to investigate in detail events with a
very low trigger probability and geometrical effects due to the array layout,
making it specially suited to be used as a fast and accurate aperture
calculator. In case more detailed studies of the radio emission and detector
response are desired, RDSim can also be used to sweep the phase-space for the
efficient creation of dedicated full simulation sets. This is particularly
important in the case of neutrino events, that have extra variables that
greatly impact shower characteristics, such as interaction or decay
depth as well as the type of interaction and it's fluctuations
RDSim, a fast and comprehensive simulation of radio detection of air showers
We present RDSim, a fast and comprehensive framework for the simulation of
the radio emission and detection of downgoing air showers. It can handle any
downgoing shower that can be simulated with ZHAireS including those induced by
CC and NC neutrino interactions and decays. RDSim is based on a
superposition toymodel that disentangles the Askaryan and geomagnetic
components of the shower emission. By using full ZHAireS simulations as input,
it is able to estimate the full radio footprint on the ground. A single input
simulation at a given energy and arrival direction can be scaled in energy and
rotated in azimuth by taking into account all relevant effects. This makes it
possible to simulate a huge number of geometries and energies using just a few
ZHAireS input simulations. The framework takes into account the main
characteristics of the detector, such as trigger setups, thresholds and antenna
patterns. To accommodate arrays that use particle detectors for triggering,
such as the Auger RD extension, it also features a second toymodel to estimate
the muon density at ground level, which is used to perform simple particle
trigger simulations. It's speed makes it possible to investigate in detail
events with a very low trigger probability, as well as many geometrical effects
due to the array layout. In case more detailed studies of the radio detection
are needed, RDSim can also be used to sweep the phase-space for the efficient
creation of dedicated full simulation sets. This is particularly important in
the case of neutrino events, that have extra variables that greatly impact
shower characteristics, such as interaction or decay depth as well as
the type of interaction and it's fluctuations.Comment: arXiv admin note: text overlap with arXiv:2307.0735
Seismic hazard in Nicaragua: a case study of Managua
Nicaragua, país centroamericano de 6.2 millones de habitantes, conocido por sus grandes lagos y volcanes activos, se encuentra en el cinturón de fuego del Pacífico, en la zona de subducción de la Placa Coco bajo la Placa Caribe. El país tiene un amplio historial de destrucción causado por sucesivos terremotos de fuerte magnitud. Centenas de fallas geológicas causan sismos frecuentes en la capital, Managua. El propósito de este trabajo es analizar el caso singular de Managua y su alto riesgo de sufrir pérdidas y daños por desastres naturales catastróficos, presentando para eso, el escenario tectónico-volcánico del país; el estudio se enfoca en los episodios más extremos ocurridos, analizando la amenaza sísmica en Managua. Como resultado de este trabajo se entrega un panorama general de los tipos de amenazas geológicas que desafían Nicaragua, concentrándose en las amenazas sísmicas y algunos episodios trágicos en el historial de desastres naturales geológicos, contribuyendo así con la difusión de conocimientos necesarios al planteamiento de políticas de mitigación y prevención de desastres geológicos sísmicos y volcánicos.Nicaragua, Central American country of 6.2 million people, is known for its large lakes and active volcanoes. Yet, the country has a long history of destruction caused by successive strong earthquakes, due to its location on the Pacific Ring of Fire in the subduction zone of the Cocos plate under the Caribbean plate. As such, Managua, the capitol, with 1.480.000 million inhabitants, is the most susceptible area to disasters, as a result of hundreds of faults that cause frequent earthquakes. The purpose of this paper is to analyze the risks that the city of Managua faces of suffering material and human losses, in the event of an extreme natural disaster, by describing the tectonic-volcanic conditions of the country, taking as theoretical reference the concepts of natural hazards and natural disasters. The empirical section analyzes data from Nicaraguan scientific institutes and specialized literature, from which an overview of the types of geological hazards that prevail in the country is laid out. By focusing on seismic hazards and on some tragic episodes in the history of geological disasters,the paper aims to contribute to the current body of knowledge necessary for the definition of mitigation and prevention policies of seismic and volcanic geological disasters
Electron paramagnetic resonance study of .pi. system interaction in dithiin derivatives
The anion radical of tetracyanodithiin (I) is shown to be a divalent sulfur system in which d-orbital participation
in conjugation is negligible. The g value (2.0024) indicates that spin-orbit coupling is very
small, and a molecular =ode1 shows that direct A-A overlap of the ethylene moieties is probable. Other
S-containing cation and anion systems are compared, including 2,5-diphenyldithiin (IV) and tetracyanothiophene
(VI). Large cation g value deviations and small anion deviations of S heterocycles are contrasted
with hydrocarbon
ESTIMATION OF COST ALLOCATION COEFFICIENTS AT THE FARM LEVEL USING AN ENTROPY APPROACH
This paper aims to estimate the farm cost allocation coefficients from whole farm input costs. An entropy approach was developed under a Tobit formulation and was applied to a sample of farms from the 2004 FADN data base for Alentejo region, Southern Portugal. A Generalized Maximum Entropy model and Cross Generalized Entropy model were developed to the sample conditions and were tested. Model results were assessed in terms of their precision and estimation power and were compared with observed data. The entropy approach showed to be a flexible and valid tool to estimate incomplete information, namely regarding farm costs.
Keywords: Generalized maximum entropy; costs; estimation; Alentejo, FADN
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