2,001 research outputs found
Integration and Conventional Systems at STAR
At the beginning of the design and construction of the STAR Detector, the
collaboration assigned a team of physicists and engineers the responsibility of
coordinating the construction of the detector. This group managed the general
space assignments for each sub-system and coordinated the assembly and planning
for the detector. Furthermore, as this group was the only STAR group with the
responsibility of looking at the system as a whole, the collaboration assigned
it several tasks that spanned the different sub-detectors. These items included
grounding, rack layout, cable distribution, electrical, power and water, and
safety systems. This paper describes these systems and their performance.Comment: 17 pages, 6 figures, Contribution to a NIM Volume Dedicated to the
Detectors and the Accelerator at RHI
Brane Fluctuation and anomalous muon magnetic moment
We study the effects of extra dimensions on the muon anomalous magnetic
moment with brane fluctuation. Since the coupling is naturally suppressed if
brane fluctuation is considered by exponential softening factor for heavier
states, the contribution from the whole Kaluza-Klein graviton tower is shown to
be finite. The recent BNL E821 result is accomodated with
dimensional gravitational scale, , in the range of
TeV (), and TeV () with the brane
tension parameter , in the range TeV.Comment: 8 pages, LaTeX, 2 eps Figures, references added, version to appear in
PL
Camera distortion self-calibration using the plumb-line constraint and minimal Hough entropy
In this paper we present a simple and robust method for self-correction of
camera distortion using single images of scenes which contain straight lines.
Since the most common distortion can be modelled as radial distortion, we
illustrate the method using the Harris radial distortion model, but the method
is applicable to any distortion model. The method is based on transforming the
edgels of the distorted image to a 1-D angular Hough space, and optimizing the
distortion correction parameters which minimize the entropy of the
corresponding normalized histogram. Properly corrected imagery will have fewer
curved lines, and therefore less spread in Hough space. Since the method does
not rely on any image structure beyond the existence of edgels sharing some
common orientations and does not use edge fitting, it is applicable to a wide
variety of image types. For instance, it can be applied equally well to images
of texture with weak but dominant orientations, or images with strong vanishing
points. Finally, the method is performed on both synthetic and real data
revealing that it is particularly robust to noise.Comment: 9 pages, 5 figures Corrected errors in equation 1
Framework for contextualized learning ecosystems
Proceedings of: 6th European Conference of Technology Enhanced Learning, EC-TEL 2011, Palermo, Italy, September 20-23, 2011Using mobile personal devices to interact with pervasive smart learning objects and services that create contextualized learning ecosystems can
enhance both the learning outcomes and the motivational states of students.
This paper defines and analyzes several pervasive learning ecosystems in which
students at the Carlos III University of Madrid interact with contextualized
learning objects and services. The technology defining the contextualized
learning environments is first introduced and later used in two user
experiments. These experiments provide data both about the learning outcomes
for students after interacting with smart learning objects and services and about
the motivational impact that the use of these technologies have on themThe research leading to these results has been partially funded
by the ARTEMISA project TIN2009-14378-C02-02 within the Spanish "Plan
Nacional de I+D+I", the Madrid regional community projects S2009/TIC-1650 and
CCG10-UC3M/TIC-4992 and the SOLITE CYTED Program 508AC0341. Thanks to
INNOVISION for providing the NFC tags for this experiment. Gustavo Ramirez-
Gonzalez is funded by the EU Programme Alban, scholarship number
E06D101768CO and by the Universidad del Cauca
Emergency Mosquito Control on a Selected Area in Eastern North Carolina After Hurricane Irene
Natural disasters such as hurricanes may contribute to mosquito abundance and, consequently, arbovirus transmission risk. In 2011, flooding from Hurricane Irene in eastern North Carolina (NC) resulted in increased mosquito populations that hindered recovery efforts. Budget shortfalls in NC have reduced the functionality of long-term mosquito surveillance and control programs; hence, many counties rely on the Federal Emergency Management Agency for post-disaster mosquito control. This pilot study examines mosquito abundance pre- and post-aerial insecticide spraying at eight study sites in Washington and Tyrrell Counties in rural eastern NC after Hurricane Irene. Percent change was calculated and compared for traps in areas that received aerial pesticide application and those that did not. Traps in spray zones show decreases in mosquito abundance when compared to control traps (treatment: −52.93%; control: 3.55%), although no significant differences (P = 0.286) were found in mosquito abundance between groups. Implications of reactive rather than proactive mosquito control responses are discussed
Imaging Spectroscopy of a White-Light Solar Flare
We report observations of a white-light solar flare (SOL2010-06-12T00:57,
M2.0) observed by the Helioseismic Magnetic Imager (HMI) on the Solar Dynamics
Observatory (SDO) and the Reuven Ramaty High-Energy Solar Spectroscopic Imager
(RHESSI). The HMI data give us the first space-based high-resolution imaging
spectroscopy of a white-light flare, including continuum, Doppler, and magnetic
signatures for the photospheric FeI line at 6173.34{\AA} and its neighboring
continuum. In the impulsive phase of the flare, a bright white-light kernel
appears in each of the two magnetic footpoints. When the flare occurred, the
spectral coverage of the HMI filtergrams (six equidistant samples spanning
\pm172m{\AA} around nominal line center) encompassed the line core and the blue
continuum sufficiently far from the core to eliminate significant Doppler
crosstalk in the latter, which is otherwise a possibility for the extreme
conditions in a white-light flare. RHESSI obtained complete hard X-ray and
\Upsilon-ray spectra (this was the first \Upsilon-ray flare of Cycle 24). The
FeI line appears to be shifted to the blue during the flare but does not go
into emission; the contrast is nearly constant across the line profile. We did
not detect a seismic wave from this event. The HMI data suggest stepwise
changes of the line-of-sight magnetic field in the white-light footpoints.Comment: 14 pages, 7 figures, Accepted by Solar Physic
Muon anomalous magnetic moment and the stabilized Randall-Sundrum scenario
We study the effects of extra dimension on the muon anomalous magnetic moment
in the stabilized Randall-Sundrum scenario. The effects of the Kaluza-Klein
states heavier than the cut-off scale expected to be of order are
neglected. Contribution from the spin-2 Kaluza-Klein states dominates over that
from the spin-0 radion. The recent BNL E821 results impose a strict constraint
on the parameter space of the model: TeV with
. Small is preferred if
is TeV scale.Comment: 9 pages, ReVTeX, reference added, version to appear in PL
A microsatellite marker for yellow rust resistance in wheat
Bulk segregant analysis (BSA) was used to identify molecular markers associated with yellow rust disease resistance in wheat (Triticum aestivum L.). DNAs isolated from the selected yellow rust tolerant and susceptible F-2 individuals derived from a cross between yellow rust resistant and susceptible wheat genotypes were used to established a "tolerant" and a "susceptible" DNA pool. The BSA was then performed on these DNA pools using 230 markers that were previously mapped onto the individual wheat chromosomes. One of the SSR markers (Xgwm382) located on chromosome group 2 (A, B, D genomes) was present in the resistant parent and the resistant bulk but not in the susceptible parent and the susceptible bulk, suggesting that this marker is linked to a yellow rust resistance gene. The presence of Xgwm382 was also tested in 108 additional wheat genotypes differing in yellow rust resistance. This analysis showed that 81% of the wheat genotypes known to be yellow rust resistant had the Xgwm382 marker, further suggesting that the presence of this marker correlates with yellow rust resistance in diverse wheat germplasm. Therefore, Xgwm382 could be useful for marker assisted selection of yellow rust resistances genotypes in wheat breeding programs
Small scale energy release driven by supergranular flows on the quiet Sun
In this article we present data and modelling for the quiet Sun that strongly suggest a ubiquitous small-scale atmospheric heating mechanism that is driven solely by converging supergranular flows.
A possible energy source for such events is the power transfer to the plasma via the work done on the magnetic field by photospheric convective flows, which exert drag of the footpoints of magnetic structures. In this paper we present evidence of small scale energy release events driven directly by the hydrodynamic forces that act on the magnetic elements in the photosphere, as a result of supergranular scale flows. We show strong spatial and temporal correlation between quiet Sun soft X-ray emission (from <i>Yohkoh</i> and <i>SOHO</i> MDI-derived flux removal events driven by deduced photospheric flows.
We also present a simple model of heating generated by flux submergence, based on particle acceleration by converging magnetic mirrors.
In the near future, high resolution soft X-ray images from XRT on the <i>Hinode</i> satellite will allow definitive, quantitative verification of our results
- …