8,646 research outputs found
Wheelchair-based game design for older adults
Few leisure activities are accessible to institutionalized older adults using wheelchairs; in consequence, they experience lower levels of perceived health than able-bodied peers. Video games have been shown to be an engaging leisure activity for older adults. In our work, we address the design of wheelchair-accessible motion-based games. We present KINECTWheels, a toolkit designed to integrate wheelchair movements into motion-based games, and Cupcake Heaven, a wheelchair-based video game designed for older adults using wheelchairs. Results of two studies show that KINECTWheels can be applied to make motion-based games wheelchair-accessible, and that wheelchair-based games engage older adults. Through the application of the wheelchair as an enabling technology in play, our work has the potential of encouraging older adults to develop a positive relationship with their wheelchair. Copyright 2013 ACM
The Black Hole Mass - Galaxy Bulge Relationship for QSOs in the SDSS DR3
We investigate the relationship between black hole mass and host galaxy
velocity dispersion for QSOs in Data Release 3 of the Sloan Digital Sky Survey.
We derive black hole mass from the broad Hbeta line width and continuum
luminosity, and the bulge stellar velocity dispersion from the [OIII] narrow
line width. At higher redshifts, we use MgII and [OII] in place of Hbeta and
[OIII]. For redshifts z < 0.5, our results agree with the black hole mass -
bulge velocity dispersion relationship for nearby galaxies. For 0.5 < z < 1.2,
this relationship appears to show evolution with redshift in the sense that the
bulges are too small for their black holes. However, we find that part of this
apparent trend can be attributed to observational biases, including a Malmquist
bias involving the QSO luminosity. Accounting for these biases, we find ~0.2
dex evolution in the black hole mass-bulge velocity dispersion relationship
between now and redshift z ~ 1.Comment: Accepted by ApJ, 15 pages, 9 figure
Quasar outflow energetics from broad absorption line variability
Quasar outflows have long been recognized as potential contributors to the
co-evolution between supermassive black holes (SMBHs) and their host galaxies.
The role of outflows in AGN feedback processes can be better understood by
placing observational constraints on wind locations and kinetic energies. We
utilize broad absorption line (BAL) variability to investigate the properties
of a sample of 71 BAL quasars with PV broad absorption. The
presence of PV BALs indicates that other BALs like CIV
are saturated, such that variability in those lines favours clouds crossing the
line of sight. We use these constraints with measurements of BAL variability to
estimate outflow locations and energetics. Our data set consists of
multiple-epoch spectra from the Sloan Digital Sky Survey and MDM Observatory.
We detect significant (4) BAL variations from 10 quasars in our sample
over rest frame time-scales between < 0.2-3.8 yr. Our derived distances for the
10 variable outflows are nominally < 1-10 pc from the SMBH using the
transverse-motion scenario, and < 100-1000 pc from the central source using
ionization-change considerations. These distances, in combination with the
estimated high outflow column densities (i.e. > 10
cm), yield outflow kinetic luminosities between ~ 0.001-1 times the
bolometric luminosity of the quasar, indicating that many absorber energies
within our sample are viable for AGN feedback.Comment: 19 pages, 3 figures, 4 tables, 1 supplementary figure, accepted to
MNRA
A Radio Transmitter for Quail
This paper describes a small radio-transmitter that has been developed specifically for use on quail. The transmitter weighs 5g, is disk-shaped (25mm diameter X 7mm thick) and is worn on the chest. It is kept in place by a harness made from nylon covered, stainless-steel wire that also functions as the antenna. Because of the transmitter\u27s light weight, shape, and position, quail seem to tolerate it very well. Also, it cannot be seen by aerial predators. The nominal signal consists of 30 msec pulses with a frequency of 1 ha. Movement produces one extra 40 rnsec pulse per cycle, 500 msec after the 30 msec pulse. These characteristics allow for relatively simple automatic detection and recording of activity. The transmission range, using a commercially available 3-element Yagi and receiver, exceeds one-half mile. Life expectancy is about 60 days. Components for the transmitter cost about $25.00 (1981)
Bell-inequality violation with a triggered photon-pair source
Here we demonstrate, for the first time, violation of Bell's inequality using
a triggered quantum dot photon-pair source without post-selection. Furthermore,
the fidelity to the expected Bell state can be increased above 90% using
temporal gating to reject photons emitted at times when collection of
uncorrelated light is more probable. A direct measurement of a CHSH Bell
inequality is made showing a clear violation, highlighting that a quantum dot
entangled photon source is suitable for communication exploiting non-local
quantum correlations.Comment: 14 pages, 4 figure
The Quasar SDSS J105041.35+345631.3: Black Hole Recoil or Extreme Double-Peaked Emitter?
The quasar SDSS J105041.35+345631.3 (z = 0.272) has broad emission lines
blueshifted by 3500 km/s relative to the narrow lines and the host galaxy. Such
an object may be a candidate for a recoiling supermassive black hole, binary
black hole, a superposition of two objects, or an unusual geometry for the
broad emission-line region. The absence of narrow lines at the broad line
redshift argues against superposition. New Keck spectra of J1050+3546 place
tight constraints on the binary model. The combination of large velocity shift
and symmetrical H-beta profile, as well as aspects of the narrow line spectrum,
make J1050+3546 an interesting candidate for black hole recoil. Other aspects
of the spectrum, however, suggest that the object is most likely an extreme
case of a ``double-peaked emitter.'' We discuss possible observational tests to
determine the true nature of this exceptional object.Comment: 5 pages, 2 figures, LaTeX; substantial revision
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