1,470 research outputs found
Conditioning super-Brownian motion on its boundary statistics, and fragmentation
We condition super-Brownian motion on "boundary statistics" of the exit
measure from a bounded domain . These are random variables defined on
an auxiliary probability space generated by sampling from the exit measure
. Two particular examples are: conditioning on a Poisson random measure
with intensity and conditioning on itself. We find the
conditional laws as -transforms of the original SBM law using Dynkin's
formulation of -harmonic functions. We give explicit expression for the
(extended) -harmonic functions considered. We also obtain explicit
constructions of these conditional laws in terms of branching particle systems.
For example, we give a fragmentation system description of the law of SBM
conditioned on , in terms of a particle system, called the backbone.
Each particle in the backbone is labeled by a measure ,
representing its descendants' total contribution to the exit measure. The
particle's spatial motion is an -transform of Brownian motion, where
depends on . At the particle's death two new particles are born,
and is passed to the newborns by fragmentation.Comment: Published in at http://dx.doi.org/10.1214/12-AOP778 the Annals of
Probability (http://www.imstat.org/aop/) by the Institute of Mathematical
Statistics (http://www.imstat.org
Recombining Plasma & Gamma-ray Emission in the Mixed-morphology Supernova Remnant 3C 400.2
3C 400.2 belongs to the mixed morphology supernova remnant class, showing
center-filled X-ray and shell-like radio morphology. We present a study of 3C
400.2 with archival Suzaku and Fermi-LAT observations. We find recombining
plasma (RP) in the Suzaku spectra of north-east and south-east regions. The
spectra of these regions are well described by two-component thermal plasma
models: The hard component is in RP, while the soft component is in collisional
ionization equilibrium (CIE) conditions. The RP has enhanced abundances
indicating that the X-ray emission has an ejecta origin, while the CIE has
solar abundances associated with the interstellar material. The X-ray spectra
of north-west and south-west regions are best fitted by a two-component thermal
plasma model: an ionizing and a CIE plasma. We have detected GeV gamma-ray
emission from 3C 400.2 at the level of 5 assuming a point-like
source model with a power-law (PL) type spectrum. We have also detected a new
GeV source at the level of 13 assuming a Gaussian extension model
with a PL type spectrum in the neighborhood of the SNR. We report the analysis
results of 3C 400.2 and the new extended gamma-ray source and discuss the
nature of gamma-ray emission of 3C 400.2 in the context of existing NANTEN CO
data, DRAO HI data, and the Suzaku X-ray analysis results.Comment: Accepted to be published in the Astrophysical Journa
Making the right call: Redesigning call centres from the bottom up
First author at the time at Department of Management, London School of Economics
The Influence of Management Style and Quality on the Operation of Incentive Pay: School Teachers' Performance Pay in England and Wales 2014-2015.
Application of Self Tuning Fuzzy Logic Control to Full Railway Vehicle Model
AbstractThis paper presents the dynamic modeling and intelligent control of the full railway vehicle against the railway irregularities. In order to safe and comfortable transportation of passengers, vibration analysis and control studies are investigated by using Matlab–Simulink software. The 54 degrees of freedom railway vehicle model is used for analysis. The controllers are placed between the car body and bogies. For reducing the car body vibrations caused by a lateral and two vertical sinusoidal track irregularities, fuzzy logic and self-tuning fuzzy logic control schemes are applied to railway vehicle. The fuzzy logic based algorithms herein are used for realizing the active control of car body vibrations. The simulations of vibration analysis are obtained in time and frequency domains and compared with uncontrolled case. A good vibration reduction performance is achieved by using applied control algorithms
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