1,471 research outputs found
Detection of faint companions through stochastic speckle discrimination
We propose a new post-processing technique for the detection of faint
companions from a sequence of adaptive optics corrected short exposures. The
algorithm exploits the difference in shape between the on-axis and off-axis
irradiance distributions and it does not require the signal to be above the
noise level. We show that the method is particularly useful in dealing with
static speckles. Its application to real and simulated data gives excellent
results in the low-signal regime where it outperforms the standard approach of
computing signal-to-noise ratio on one long exposure. We also show that
accurate noise estimation in adaptive optics images of close companions is
rendered impossible due to the presence of static speckles. This new method
provides means of reliable estimation of the confidence intervals for the
detection hypothesis.Comment: accepted for publication in Ap
Categories of Product Innovations. A Prospective Categorization Framework for Innovation Projects in Early Development Phases Based on Empirical Data
AbstractMost of the categorization frameworks for innovation projects in early development phases are not designed for supporting the product engineer in decision making and leave space for further improvement. Based on empirical data from 13 innovation projects, the authors introduce a novel categorization framework for innovation projects and discuss the relevance of identified key criteria. The focus is to provide a fundamental understanding of the varieties of product innovation projects and establish a basis for decision support frameworks regarding the adoption of tools and methods
Performance Studies of Prototype II for the CASTOR forward Calorimeter at the CMS Experiment
We present results of the performance of the second prototype of the CASTOR
quartz-tungsten sampling calorimeter, to be installed in the very forward
region of the CMS experiment at the LHC. The energy linearity and resolution,
as well as the spatial resolution of the prototype to electromagnetic and
hadronic showers are studied with E=20-200 GeV electrons, E=20-350 GeV pions,
and E=50,150 GeV muons from beam tests carried out at CERN/SPS in 2004. The
responses of the calorimeter using two different types of photodetectors
(avalanche photodiodes APDs, and photomultiplier tubes PMTs) are compared.Comment: 16 pages, 22 figs., submitted to EPJ-
Formation of Centauro and Strangelets in Nucleus-Nucleus Collisions at the LHC and their Identification by the ALICE Experiment
We present a phenomenological model which describes the formation of a
Centauro fireball in nucleus-nucleus interactions in the upper atmosphere and
at the LHC, and its decay to non-strange baryons and Strangelets. We describe
the CASTOR detector for the ALICE experiment at the LHC. CASTOR will probe, in
an event-by-event mode, the very forward, baryon-rich phase space 5.6 < \eta <
7.2 in 5.5 A TeV central Pb + Pb collisions. We present results of simulations
for the response of the CASTOR calorimeter, and in particular to the traversal
of Strangelets.Comment: 4 pages, 4 figures, to appear in the proceedings of the 26th ICR
CASTOR: Centauro and Strange Object Research in nucleus-nucleus collisions at LHC
We describe the CASTOR detector designed to probe the very forward,
baryon-rich rapidity region in nucleus-nucleus collisions at the LHC. We
present a phenomenological model describing the formation of a QGP fireball in
a high baryochemical potential environment, and its subsequent decay into
baryons and strangelets. The model explains Centauros and the long-penetrating
component and makes predictions for the LHC.
Simulations of Centauro-type events were done. To study the response of the
apparatus to new effects different exotic species (DCC, Centauros, strangelets
etc.) were passed through the deep calorimeter. The energy deposition pattern
in the calorimeter appears to be a new clear signature of the QGP.Comment: Talk given by E. Gladysz-Dziadus for the CASTOR group, Intern.
Workshop on Nuclear Theory, 10-15 June, 2002, Bulgaria, Rila Mountains, 15
pages, 14 figure
5,6-dehydro[3.3]Paracyclophane: Bridged benzobarrelene formation by intramolecular trapping of a novel aryne
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/21925/1/0000332.pd
Speckle noise and dynamic range in coronagraphic images
This paper is concerned with the theoretical properties of high contrast
coronagraphic images in the context of exoplanet searches. We derive and
analyze the statistical properties of the residual starlight in coronagraphic
images, and describe the effect of a coronagraph on the speckle and photon
noise. Current observations with coronagraphic instruments have shown that the
main limitations to high contrast imaging are due to residual quasi-static
speckles. We tackle this problem in this paper, and propose a generalization of
our statistical model to include the description of static, quasi-static and
fast residual atmospheric speckles. The results provide insight into the
effects on the dynamic range of wavefront control, coronagraphy, active speckle
reduction, and differential speckle calibration. The study is focused on
ground-based imaging with extreme adaptive optics, but the approach is general
enough to be applicable to space, with different parameters.Comment: 31 pages, 18 figure
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