11,054 research outputs found
Recommended from our members
Do social networking groups support online petitions?
This article is the post-print version of the final paper that has been accepted for publication and is forthcoming in Transforming Government: People, Process and Policy. Copyright @ Emerald Group Publishing LimitedEPetitioning has been emerging as arguably the most important eParticipation institutional activity. This paper aims to provide some insights into how ePetitions are perceived and supported by social networking sites. The connection between the UK government’s ePetitioning system and social networking groups linking to governmental petitions was investigated. Online data from Facebook were collected and analysed with respect to numbers of supporters compared to official signatures. The results indicate that although the process of signing an official petition is not more complex than joining a Facebook group, the membership of respective Facebook groups can be much higher. In particular, certain topics experienced very high support on Facebook which did not convert to signatures. The paper raises interesting questions about the potential uptake of citizen-government interactions in policy making mechanisms.The online research tool used for data collection in this paper was developed by Steven Sams who acknowledges support by the World Class University (WCU) program through the National Research Foundation of Korea. The program is funded by the Korean Ministry of Education, Science and Technology (No. 515-82-06574
Teaching Teachers for the Future (TTF) Project: Development of the TTF TPACK survey instrument
This paper presents a summary of the key findings of the TTF TPACK Survey developed and administered for the Teaching the Teachers for the Future (TTF) Project implemented in 2011. The TTF Project, funded by an Australian Government ICT Innovation Fund grant, involved all 39 Australian Higher Education Institutions which provide initial teacher education. TTF data collections were undertaken at the end of Semester 1 (T1) and at the end of Semester 2 (T2) in 2011. A total of 12881 participants completed the first survey (T1) and 5809 participants completed the second survey (T2). Groups of like-named items from the T1 survey were subject to a battery of complementary data analysis techniques. The psychometric properties of the four scales: Confidence - teacher items; Usefulness - teacher items; Confidence - student items; Usefulness- student items, were confirmed both at T1 and T2. Among the key findings summarised, at the national level, the scale: Confidence to use ICT as a teacher showed measurable growth across the whole scale from T1 to T2, and the scale: Confidence to facilitate student use of ICT also showed measurable growth across the whole scale from T1 to T2. Additional key TTF TPACK Survey findings are summarised
Discovery of Resolved Debris Disk Around HD 131835
We report the discovery of the resolved disk around HD 131835 and present the
analysis and modeling of its thermal emission. HD 131835 is a ~15 Myr A2 star
in the Scorpius-Centaurus OB association at a distance of 122.7 +16.2 -12.8
parsec. The extended disk has been detected to ~1.5" (200 AU) at 11.7 {\mu}m
and 18.3 {\mu}m with T-ReCS on Gemini South. The disk is inclined at an angle
of ~75{\deg} with the position angle of ~61{\deg}. The flux of HD 131835 system
is 49.3+-7.6 mJy and 84+-45 mJy at 11.7 {\mu}m and 18.3 {\mu}m respectively. A
model with three grain populations gives a satisfactory fit to both the
spectral energy distribution and the images simultaneously. This best-fit model
is composed of a hot continuous power-law disk and two rings. We characterized
the grain temperature profile and found that the grains in all three
populations are emitting at temperatures higher than blackbodies. In
particular, the grains in the continuous disk are unusually warm; even when
considering small graphite particles as the composition.Comment: 11 pages, 5 figures, Accepted for Publication in Ap
A Ring of Warm Dust in the HD 32297 Debris Disk
We report the detection of a ring of warm dust in the edge-on disk
surrounding HD 32297 with the Gemini-N/MICHELLE mid-infrared imager. Our
N'-band image shows elongated structure consistent with the orientation of the
scattered-light disk. The Fnu(11.2 um) = 49.9+/-2.1 mJy flux is significantly
above the 28.2+/-0.6 mJy photosphere. Subtraction of the stellar point spread
function reveals a bilobed structure with peaks 0.5"-0.6" from the star. An
analysis of the stellar component of the SED suggests a spectral type later
than A0, in contrast to commonly cited literature values. We fit
three-dimensional, single-size grain models of an optically thin dust ring to
our image and the SED using a Markov chain Monte Carlo algorithm in a Bayesian
framework. The best-fit effective grain sizes are submicron, suggesting the
same dust population is responsible for the bulk of the scattered light. The
inner boundary of the warm dust is located 0.5"-0.7" (~65 AU) from the star,
which is approximately cospatial with the outer boundary of the scattered-light
asymmetry inward of 0.5". The addition of a separate component of larger,
cooler grains that provide a portion of the 60 um flux improves both the
fidelity of the model fit and consistency with the slopes of the
scattered-light brightness profiles. Previous indirect estimates of the stellar
age (~30 Myr) indicate the dust is composed of debris. The peak vertical
optical depths in our models (~0.3-1 x 1e-2) imply that grain-grain collisions
likely play a significant role in dust dynamics and evolution. Submicron grains
can survive radiation pressure blow-out if they are icy and porous. Similarly,
the inferred warm temperatures (130-200 K) suggest that ice sublimation may
play a role in truncating the inner disk.Comment: ApJ accepted, 8 pages, 4 figure
Demonstration of a Near-IR Laser Comb for Precision Radial Velocity Measurements in Astronomy
We describe a successful effort to produce a laser comb around 1.55 m in
the astronomical H band using a method based on a line-referenced,
electro-optical-modulation frequency comb. We discuss the experimental setup,
laboratory results, and proof of concept demonstrations at the NASA Infrared
Telescope Facility (IRTF) and the Keck-II telescope. The laser comb has a
demonstrated stability of 200 kHz, corresponding to a Doppler precision of
~0.3 m/s. This technology, when coupled with a high spectral resolution
spectrograph, offers the promise of 1 m/s radial velocity precision suitable
for the detection of Earth-sized planets in the habitable zones of cool M-type
stars
First scattered light images of debris disks around HD 53143 and HD 139664
We present the first scattered light images of debris disks around a K star
(HD 53143) and an F star (HD 139664) using the coronagraphic mode of the
Advanced Camera for Surveys (ACS) aboard the Hubble Space Telescope (HST). With
ages 0.3 - 1 Gyr, these are among the oldest optically detected debris disks.
HD 53143, viewed ~45 degrees from edge-on, does not show radial variation in
disk structure and has width >55 AU. HD 139664 is seen close to edge-on and has
belt-like morphology with a dust peak 83 AU from the star and a distinct outer
boundary at 109 AU. We discuss evidence for significant diversity in the radial
architecture of debris disks that appears unconnected to stellar spectral type
or age. HD 139664 and possibly the solar system belong in a category of narrow
belts 20-30 AU wide. HD 53143 represents a class of wide disk architecture with
characteristic width >50 AU.Comment: 7 pages, 3 figure
Infinite partition monoids
Let and be the partition monoid and symmetric
group on an infinite set . We show that may be generated by
together with two (but no fewer) additional partitions, and we
classify the pairs for which is
generated by . We also show that may be generated by the set of all idempotent partitions
together with two (but no fewer) additional partitions. In fact,
is generated by if and only if it is
generated by . We also
classify the pairs for which is
generated by . Among other results, we show
that any countable subset of is contained in a -generated
subsemigroup of , and that the length function on
is bounded with respect to any generating set
CCRS proposal for evaluating LANDSAT-4 MSS and TM data
The measurement of registration errors in LANDSAT MSS data is discussed as well as the development of a revised algorithm for the radiometric calibration of TM data and the production of a geocoded TM image
Ferromagnetism in substituted zinc oxide
Room-temperature ferromagnetism is observed in (110) oriented ZnO films
containing 5 at % of Sc, Ti, V, Fe, Co or Ni, but not Cr, Mn or Cu ions. There
are large moments, 1.9 and 0.5 muB/atom for Co- and Ti-substituted oxides,
respectively. Sc-substituted ZnO shows also a moment of 0.3 muB/Sc.
Magnetization is very anisotropic, with variations of up to a factor three
depending on the orientation of the applied field relative to the R-cut
sapphire substrates. Results are interpreted in terms of a spin-split donor
impurity band model, which can account for ferromagnetism in insulating or
conducting high-k oxides with concentrations of magnetic ions that lie far
below the percolation threshold. The variation of the ferromagnetism with
oxygen pressure used during film growth is evidence of a link between
ferromagnetism and defect concentration.Comment: 15 pages, 4 figure
- …