1,887 research outputs found
Formaliser la multiplicité des constructions sociales de la réalité par les systèmes multi-agents institutionnels
Les institutions et les normes ont été traités de différentes façons : dans nos travaux en modéli- sation des dynamiques sociales du point de vue de l'anthropologie du droit où une multiplicité d'interprétations légales des acteurs, des choses et des actes était nécessaire, en philosophie qui insiste sur le rôle des définitions dans les institutions à travers les normes constitutives, et dans le domaine des systèmes multi-agents pour spécifier les interactions entre agents à tra- vers une multiplicité de rôles. Nous proposons dans ce papier une synthèse permettant de trai- ter conjointement la multiplicité des interpréta- tions, des normes constitutives et des structures de rôles. Nous proposons également une spé- cification de systèmes multi-agents institution- nels spatialisés, montrant sa capacité à rendre compte syntaxiquement et sémantiquement de cette synthèse. En particulier, nous montrons comment cette multiplicité interprétative struc- ture l'espace en autant de territoire
Assessment of the potential of MERIS near-infrared water vapour products to correct ASAR interferometric measurements
Atmospheric water vapour is a major limitation for high precision Interferometric Synthetic Aperture Radar (InSAR) applications due to its significant impact on microwave signals. We propose a statistical criterion to test whether an independent water vapour product can reduce water vapour effects on InSAR interferograms, and assess the potential of the Medium Resolution Imaging Spectrometer (MERIS) near-infrared water vapour products for correcting Advanced SAR (ASAR) data. Spatio-temporal comparisons show c. 1.1mm
agreement between MERIS and GPS/radiosonde water vapour products in terms of standard deviations. One major limitation with the use of MERIS water vapour products is the frequency of cloud free conditions. Our analysis indicates that in spite of the low global cloud free conditions (~25%), the frequency can be much higher for certain areas such as Eastern Tibet (~38%) and Southern
California (~48%). This suggests that MERIS water vapour products show potential for correcting ASAR interferometric measurements in certain regions
A simple and quick sensitivity analysis method for methane isotopologues detection with GOSAT-TANSO-FTS
Measurements of methane isotopologues can differentiate between different source types, be
they biogenic (e.g. marsh lands) or abiogenic (e.g. industry). Global measurements of these
isotopologues would greatly benefit the current disconnect between ‘top-down’ (knowledge from
chemistry transport models and satellite measurements) and ‘bottom-up’ (in situ measurement
inventories) methane measurements. However, current measurements of these isotopologues are
limited to a small number of in situ studies and airborne studies. In this paper we investigate the
potential for detecting the second most common isotopologue of methane (13CH4) from space using
the Japanese Greenhouse Gases Observing Satellite applying a quick and simple residual radiance
analysis technique. The method allows for a rapid analysis of spectral regions, and can be used
to teach university students or advanced school students about radiative transfer analysis. Using
this method we find limited sensitivity to 13CH4, with detections limited to total column methane
enhancements of >6%, assuming a desert surface albedo of >0.3
Circulating microparticles from pulmonary hypertensive rats are vectors of oxidative stress
Date du colloque : 04/2010National audienc
Negative specific heat in a thermodynamic model of multifragmentation
We consider a soluble model of multifragmentation which is similar in spirit
to many models which have been used to fit intermediate energy heavy ion
collision data. In this model is always positive but for finite nuclei
can be negative for some temperatures and pressures. Furthermore,
negative values of can be obtained in canonical treatment. One does not
need to use the microcanonical ensemble. Negative values for can persist
for systems as large as 200 paticles but this depends upon parameters used in
the model calculation. As expected, negative specific heats are absent in the
thermodynamic limit.Comment: Revtex, 13 pages including 6 figure
Photonic band structure of highly deformable, self-assembling systems
We calculate the photonic band structure at normal incidence of highly
deformable, self-assembling systems - cholesteric elastomers subjected to
external stress. Cholesterics display brilliant reflection and lasing owing to
gaps in their photonic band structure. The band structure of cholesteric
elastomers varies sensitively with strain, showing new gaps opening up and
shifting in frequency. A novel prediction of a total band gap is made, and is
expected to occur in the vicinity of the previously observed de Vries bandgap,
which is only for one polarisation
Model of multifragmentation, Equation of State and phase transition
We consider a soluble model of multifragmentation which is similar in spirit
to many models which have been used to fit intermediate energy heavy ion
collision data. We draw a p-V diagram for the model and compare with a p-V
diagram obtained from a mean-field theory. We investigate the question of
chemical instability in the multifragmentation model. Phase transitions in the
model are discussed.Comment: Revtex, 9 pages including 6 figures: some change in the text and Fig.
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