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East Midlands FRESA targets project
Reviewed employment and skills targets in use by organisations in the East Midlands in order to inform the development of targets for the East Midlands Framework for Employment and Skills action (FRESA). Established target development process later adopted by emda for 2006 RES. Developed criteria for applying to future selection of economic performance monitoring metrics - especially for skills, based on extant best practice, such as the Treasury's 'Green Book'
Light Powered Keyboard Charging for Full-screen Devices
This disclosure describes a detachable keyboard for use with foldable computing devices. The keyboard can be charged via illumination from the display of the foldable device. Photovoltaic cells are provided on the bottom surface of the keyboard and generate electrical power from display illumination when the keyboard is placed on the display such as an organic light emitting diode (OLED) display. The illumination intensity of the pixels located directly beneath the keyboard can be adjusted to its maximum level to enable faster charging
Position-Based Multi-Agent Dynamics for Real-Time Crowd Simulation (MiG paper)
Exploiting the efficiency and stability of Position-Based Dynamics (PBD), we
introduce a novel crowd simulation method that runs at interactive rates for
hundreds of thousands of agents. Our method enables the detailed modeling of
per-agent behavior in a Lagrangian formulation. We model short-range and
long-range collision avoidance to simulate both sparse and dense crowds. On the
particles representing agents, we formulate a set of positional constraints
that can be readily integrated into a standard PBD solver. We augment the
tentative particle motions with planning velocities to determine the preferred
velocities of agents, and project the positions onto the constraint manifold to
eliminate colliding configurations. The local short-range interaction is
represented with collision and frictional contact between agents, as in the
discrete simulation of granular materials. We incorporate a cohesion model for
modeling collective behaviors and propose a new constraint for dealing with
potential future collisions. Our new method is suitable for use in interactive
games.Comment: 9 page
Radioactive Scandium in the Youngest Galactic Supernova Remnant G1.9+0.3
We report the discovery of thermal X-ray emission from the youngest Galactic
supernova remnant G1.9+0.3, from a 237-ks Chandra observation. We detect strong
K-shell lines of Si, S, Ar, Ca, and Fe. In addition, we detect a 4.1 keV line
with 99.971% confidence which we attribute to 44Sc, produced by electron
capture from 44Ti. Combining the data with our earlier Chandra observation
allows us to detect the line in two regions independently. For a remnant age of
100 yr, our measured total line strength indicates synthesis of solar masses of 44Ti, in the range predicted for both Type Ia and
core-collapse supernovae, but somewhat smaller than the
solar masses reported for Cas A. The line spectrum indicates supersolar
abundances. The Fe emission has a width of about 28,000 km/s, consistent with
an age of about 100 yr and with the inferred mean shock velocity of 14,000 km/s
deduced assuming a distance of 8.5 kpc. Most thermal emission comes from
regions of lower X-ray but higher radio surface brightness. Deeper observations
should allow more detailed spatial mapping of scandium, with significant
implications for models of nucleosynthesis in Type Ia supernovae.Comment: 5 pages, 3 figures, accepted for publication in ApJ
Nonuniform Expansion of the Youngest Galactic Supernova Remnant G1.9+0.3
We report measurements of X-ray expansion of the youngest Galactic supernova
remnant, G1.9+0.3, using Chandra observations in 2007, 2009, and 2011. The
measured rates strongly deviate from uniform expansion, decreasing radially by
about 60% along the X-ray bright SE-NW axis from 0.84% +/- 0.06% per yr to
0.52% +/- 0.03% per yr. This corresponds to undecelerated ages of 120-190 yr,
confirming the young age of G1.9+0.3, and implying a significant deceleration
of the blast wave. The synchrotron-dominated X-ray emission brightens at a rate
of 1.9% +/- 0.4% per yr. We identify bright outer and inner rims with the blast
wave and reverse shock, respectively. Sharp density gradients in either ejecta
or ambient medium are required to produce the sudden deceleration of the
reverse shock or the blast wave implied by the large spread in expansion ages.
The blast wave could have been decelerated recently by an encounter with a
modest density discontinuity in the ambient medium, such as found at a wind
termination shock, requiring strong mass loss in the progenitor. Alternatively,
the reverse shock might have encountered an order-of-magnitude density
discontinuity within the ejecta, such as found in pulsating delayed-detonation
Type Ia models. We demonstrate that the blast wave is much more decelerated
than the reverse shock in these models for remnants at ages similar to
G1.9+0.3. Similar effects may also be produced by dense shells possibly
associated with high-velocity features in Type Ia spectra. Accounting for the
asymmetry of G1.9+0.3 will require more realistic 3D Type Ia models.Comment: 6 pages, 4 figures, accepted for publication in ApJ Letters, minor
revision
The Youngest Galactic Supernova Remnant: G1.9+0.3
Our 50 ks Chandra observation of the small radio supernova remnant (SNR)
G1.9+0.3 shows a complete shell structure with strong bilateral symmetry, about
in diameter. The radio morphology is also shell-like, but only about
in diameter, based on observations made in 1985. We attribute the size
difference to expansion between 1985 and our Chandra observations of 2007.
Expansion is confirmed in comparing radio images from 1985 and 2008. We deduce
that G1.9+0.3 is of order 100 years old -- the youngest supernova remnant in
the Galaxy. Based on a very high absorbing column density of cm, we place G1.9+0.3 near the Galactic Center, at a distance
of about 8.5 kpc, where the mean remnant radius would be about 2 pc, and the
required expansion speed about km s. The X-ray spectrum is
featureless and well-described by the exponentially cut off synchrotron model
{\tt srcut}. With the radio flux at 1 GHz fixed at 0.9 Jy, we find a spectral
index of 0.65 and a rolloff frequency of Hz. The implied
characteristic rolloff electron energy of about
TeV is the highest ever reported for a shell supernova remnant. It can easily
be reached by standard diffusive shock acceleration, given the very high shock
velocities; it can be well described by either age-limited or
synchrotron-loss-limited acceleration. Not only is G1.9+0.3 the youngest known
Galactic remnant, it is also only the fourth Galactic X-ray
synchrotron-dominated shell supernova remnant.Comment: 4 pages, 5 figures; revised to include new radio data and accepted
for ApJ
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