32,900 research outputs found
Threat perception while viewing single intruder conflicts on a cockpit display of traffic information
Subjective estimates of the threat posed by a single intruder aircraft were determined by showing pilots photographs of a cockpit display of traffic information. The time the intruder was away from the point of minimum separation was found to be the major determinant of the perception of threat. When asked to choose a maneuver to reduce the conflict, pilots selected maneuvers with a bias toward those that would have kept the intruders in sight had they been visible out the cockpit window
Star formation and accretion in the circumnuclear disks of active galaxies
We explore the evolution of supermassive black holes (SMBH) centered in a
circumnuclear disk (CND) as a function of the mass supply from the host galaxy
and considering different star formation laws, which may give rise to a
self-regulation via the injection of supernova-driven turbulence. A system of
equations describing star formation, black hole accretion and angular momentum
transport was solved for an axisymmetric disk in which the gravitational
potential includes contributions from the black hole, the disk and the hosting
galaxy. Our model extends the framework provided by Kawakatu et al. (2008) by
separately considering the inner and outer part of the disk, and by introducing
a potentially non-linear dependence of the star formation rate on the gas
surface density and the turbulent velocity. The star formation recipes are
calibrated using observational data for NGC 1097, while the accretion model is
based on turbulent viscosity as a source of angular momentum transport in a
thin viscous accretion disk. We find that current data provide no strong
constraint on the star formation recipe, and can in particular not distinguish
between models entirely regulated by the surface density, and models including
a dependence on the turbulent velocity. The evolution of the black hole mass,
on the other hand, strongly depends on the applied star formation law, as well
as the mass supply from the host galaxy. We suggest to explore the star
formation process in local AGN with high-resolution ALMA observations to break
the degeneracy between different star formation models.Comment: 13 pages, 15 figures, 6 tables, accepted at A&
6D Muon Ionization Cooling with an Inverse Cyclotron
A large admittance sector cyclotron filled with LiH wedges surrounded by
helium or hydrogen gas is explored. Muons are cooled as they spiral
adiabatically into a central swarm. As momentum approaches zero, the momentum
spread also approaches zero. Long bunch trains coalesce. Energy loss is used to
inject the muons into the outer rim of the cyclotron. The density of material
in the cyclotron decreases adiabatically with radius. The sector cyclotron
magnetic fields are transformed into an azimuthally symmetric magnetic bottle
in the center. Helium gas is used to inhibit muonium formation by positive
muons. Deuterium gas is used to allow captured negative muons to escape via the
muon catalyzed fusion process. The presence of ionized gas in the center may
automatically neutralize space charge. When a bunch train has coalesced into a
central swarm, it is ejected axially with an electric kicker pulse.Comment: Five pages. LaTeX, three postscript figure files. To appear in the
AIP Conference Proceedings for COOL05: International Workshop on Beam
Cooling, Galena, IL, 18-23 Sept. 200
Effect of field of view and monocular viewing on angular size judgements in an outdoor scene
Observers typically overestimate the angular size of distant objects. Significantly, overestimations are greater in outdoor settings than in aircraft visual-scene simulators. The effect of field of view and monocular and binocular viewing conditions on angular size estimation in an outdoor field was examined. Subjects adjusted the size of a variable triangle to match the angular size of a standard triangle set at three greater distances. Goggles were used to vary the field of view from 11.5 deg to 90 deg for both monocular and binocular viewing. In addition, an unrestricted monocular and binocular viewing condition was used. It is concluded that neither restricted fields of view similar to those present in visual simulators nor the restriction of monocular viewing causes a significant loss in depth perception in outdoor settings. Thus, neither factor should significantly affect the depth realism of visual simulators
A Pulsed Synchrotron for Muon Acceleration at a Neutrino Factory
A 4600 Hz pulsed synchrotron is considered as a means of accelerating cool
muons with superconducting RF cavities from 4 to 20 GeV/c for a neutrino
factory. Eddy current losses are held to less than a megawatt by the low
machine duty cycle plus 100 micron thick grain oriented silicon steel
laminations and 250 micron diameter copper wires. Combined function magnets
with 20 T/m gradients alternating within single magnets form the lattice. Muon
survival is 83%.Comment: 4 pages, 1 figures, LaTeX, 5th International Workshop on Neutrino
Factories and Superbeams (NuFact 03), 5-11 Jun 2003, New Yor
Guidance, Flight Mechanics and Trajectory Optimization. Volume 5 - State Determination And/or Estimation
Guidance, flight mechanics, and trajectory optimizatio
Missing in Action? Electronic Gaming Machines in Gambling Studies Research
In the past thirty years casinos across the world have become dominated by the rise of “electronic gaming machines” (EGMs). Expanding with tremendous speed, this technology has arguably become the dominant form of non-online gambling around the world at time of writing (DeMichele, 2017; Schwartz, 2018). EGMs are also noted as being one of the most harmful forms of gambling, with significant numbers of players betting beyond their financial limits (MacLaren et al, 2012; Stewart & Wohl, 2013), spending a disproportionate amount of time playing (Cummings, 1999; Ballon, 2005; Schüll, 2012; cf. Dickerson, 1996), becoming disconnected from the world outside of the “zone” (Schüll, 2012) of gambling play, and even becoming bankrupt or otherwise financially crippled as a result of their use (Petry, 2003; Scarf et al, 2011). Using metadata from Web of Science and Scopus databases, we analysed peer-reviewed gambling research produced in Australia, New Zealand, North America and the UK published between 1996 and 2016. Surprisingly, we found that the overwhelming of majority of articles do not specifically address EGMs as the most popular and pervasive gambling technology available. Our paper teases out some concerning implications of this finding for the interdisciplinary field of gambling studies
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