14,421 research outputs found
Digital television, Personal Video Recorders and convergence in the Australian home
Out of the confusion of delivery technologies for domestic digital video, the function of a Personal Video Recorder (PVR) that has a content management system based on an electronic program guide emerges as a key component of a home entertainment system. Serving as a content manager for video broadcasts for free-to-air and pay-TV, PVRs can automatically record, sort, schedule, store and integrate video material from different sources in a convenient, easy-to-use and timely fashion. Devices with PVR functionality are still not yet in widespread use in Australian homes, but are the increasing subject of pioneering commercial enterprise, innovative experimentation and open-source community development. The concept of a MADE system is introduced as a system with converged functionality for Media, Automation, Data, and Entertainment. This paper describes and compares three systems with PVR functionality and evaluates their current and future roles as a component for MADE systems in Australia: the TiVo appliance, the MythTV open source software for Linux; and a Topfield set top box using IceGuide. The drivers for and threats to the convergence of functionality towards a MADE system are also considered
Digital television, Personal Video Recorders and Media, Automation, Data and Entertainment convergence in the home
Out of the confusion of possible delivery technologies for domestic digital video entertainment, the personal video recorder (PVR) with an electronic program guide (EPG) emerges as a key component. Serving as a content manager for video broadcasts, PVRs can automatically record, sort, schedule, store and integrate video material from different sources in a convenient, easy-to-use and timely fashion. Such devices are gradually being adopted in the homes of the developed world, and are the increasing subject of pioneering commercial enterprise, innovative experimentation and open-source community development. Going one step further, the concept of a 'MADE system' is introduced as a system with converged functionality for media, automation, data and entertainment. This article describes and compares three systems with PVR functionality and evaluates their current and future roles as a component for MADE systems. The drivers for and threats to the convergence of functionality towards a MADE system are also considered
Grassland Landscape Design: Working with Land-Managers
We are entering an era of landscape design in order to simultaneously tackle largescale issues such as salinity and rising water tables, whole-farm profitability and the maintenance or enhancement of rural communities. In Australia, an important element of landscape design will be the reintroduction or broadening of the base of perennial grasses within farm systems. The goal of this project was to accelerate awareness and adoption of perennial grasses in a large but ecologically-specific area, namely the already-cleared steep uplands in the high rainfall recharge areas of the Murray-Darling Basin. We used a participatory model, in which land-managers made monthly observations of grassland composition and condition, and of livestock. This paper describes the project, some of the outcomes eg that stocking rate varied more within grassland types than between types, and could be relatively high, eg 10 adult sheep equivalents per hectare on indigenous grasslands. Land-managers\u27 data eg height, were coupled to correlations with other variates such as dry matter and leaf area, to derive seasonal estimates of digestible dry matter-on-offer, and environmentally-important variates such as seasonal evaporation. Collection of these data by land-managers creates opportunities for local awareness and the development of regional data sets which are not possible through traditional small-plot research. In our view, land-manager participation, leading to awareness and in some cases enthusiasm, will be a prerequisite for regional landscape design
Noncommutative Einstein Equations
We study a noncommutative deformation of general relativity where the
gravitational field is described by a matrix-valued symmetric two-tensor field.
The equations of motion are derived in the framework of this new theory by
varying a diffeomorphisms and gauge invariant action constructed by using a
matrix-valued scalar curvature. Interestingly the genuine noncommutative part
of the dynamical equations is described only in terms of a particular tensor
density that vanishes identically in the commutative limit. A noncommutative
generalization of the energy-momentum tensor for the matter field is studied as
well.Comment: 17 Pages, LaTeX, reference adde
On the Persistent Shape and Coherence of Pulsating Auroral Patches
The pulsating aurora covers a broad range of fluctuating shapes that are
poorly characterized. The purpose of this paper is therefore to provide
objective and quantitative measures of the extent to which pulsating auroral
patches maintain their shape, drift and fluctuate in a coherent fashion. We
present results from a careful analysis of pulsating auroral patches using
all-sky cameras. We have identified four well-defined individual patches that
we follow in the patch frame of reference. In this way we avoid the space-time
ambiguity which complicates rocket and satellite measurements. We find that the
shape of the patches is remarkably persistent with 85-100% of the patch being
repeated for 4.5-8.5 min. Each of the three largest patches has a temporal
correlation with a negative dependence on distance, and thus does not fluctuate
in a coherent fashion. A time-delayed response within the patches indicates
that the so-called streaming mode might explain the incoherency. The patches
appear to drift differently from the SuperDARN-determined
X convection velocity.
However, in a nonrotating reference frame the patches drift with 230-287 m/s in
a north eastward direction, which is what typically could be expected for the
convection return flow
Chaos in a Relativistic 3-body Self-Gravitating System
We consider the 3-body problem in relativistic lineal gravity and obtain an
exact expression for its Hamiltonian and equations of motion. While
general-relativistic effects yield more tightly-bound orbits of higher
frequency compared to their non-relativistic counterparts, as energy increases
we find in the equal-mass case no evidence for either global chaos or a
breakdown from regular to chaotic motion, despite the high degree of
non-linearity in the system. We find numerical evidence for a countably
infinite class of non-chaotic orbits, yielding a fractal structure in the outer
regions of the Poincare plot.Comment: 9 pages, LaTex, 3 figures, final version to appear in Phys. Rev. Let
Chaos in an Exact Relativistic 3-body Self-Gravitating System
We consider the problem of three body motion for a relativistic
one-dimensional self-gravitating system. After describing the canonical
decomposition of the action, we find an exact expression for the 3-body
Hamiltonian, implicitly determined in terms of the four coordinate and momentum
degrees of freedom in the system. Non-relativistically these degrees of freedom
can be rewritten in terms of a single particle moving in a two-dimensional
hexagonal well. We find the exact relativistic generalization of this
potential, along with its post-Newtonian approximation. We then specialize to
the equal mass case and numerically solve the equations of motion that follow
from the Hamiltonian. Working in hexagonal-well coordinates, we obtaining
orbits in both the hexagonal and 3-body representations of the system, and plot
the Poincare sections as a function of the relativistic energy parameter . We find two broad categories of periodic and quasi-periodic motions that we
refer to as the annulus and pretzel patterns, as well as a set of chaotic
motions that appear in the region of phase-space between these two types.
Despite the high degree of non-linearity in the relativistic system, we find
that the the global structure of its phase space remains qualitatively the same
as its non-relativisitic counterpart for all values of that we could
study. However the relativistic system has a weaker symmetry and so its
Poincare section develops an asymmetric distortion that increases with
increasing . For the post-Newtonian system we find that it experiences a
KAM breakdown for : above which the near integrable regions
degenerate into chaos.Comment: latex, 65 pages, 36 figures, high-resolution figures available upon
reques
High resolution Ge/Li/ spectrometer reduces rate-dependent distortions at high counting rates
Modified spectrometer system with a low-noise preamplifier reduces rate-dependent distortions at high counting rates, 25,000 counts per second. Pole-zero cancellation minimizes pulse undershoots due to multiple time constants, baseline restoration improves resolution and prevents spectral shifts
Unified model for network dynamics exhibiting nonextensive statistics
We introduce a dynamical network model which unifies a number of network
families which are individually known to exhibit -exponential degree
distributions. The present model dynamics incorporates static (non-growing)
self-organizing networks, preferentially growing networks, and (preferentially)
rewiring networks. Further, it exhibits a natural random graph limit. The
proposed model generalizes network dynamics to rewiring and growth modes which
depend on internal topology as well as on a metric imposed by the space they
are embedded in. In all of the networks emerging from the presented model we
find q-exponential degree distributions over a large parameter space. We
comment on the parameter dependence of the corresponding entropic index q for
the degree distributions, and on the behavior of the clustering coefficients
and neighboring connectivity distributions.Comment: 11 pages 8 fig
Epigenetics, Eh! A meeting summary of the canadian conference on epigenetics
In May 2011, the Canadian Conference on Epigenetics Epigenetics Eh! was held in London, Canada. The objectives of this conference were to showcase the breadth of epigenetic research on environment and health across Canada and to provide the catalyst to develop collaborative Canadian epigenetic research opportunities, similar to existing international epigenetic initiatives in the US and Europe. With ten platform sessions and two sessions with over 100 poster presentations, this conference featured cutting-edge epigenetic research, presented by Canadian and international principal investigators and their trainees in the feld of epigenetics and chromatin dynamics. An EpigenART competition included ten artists, creating a unique opportunity for artists and scientists to interact and explore their individual interpretations of this scientific discipline. The conference provided a unique venue for a significant cross-section of Canadian epigenetic researchers from diverse disciplines to meet, interact, collaborate and strategize at the national level. © 2011 Landes Bioscience
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