25,887 research outputs found
Texas Natural Resources Inventory and Monitoring System (TNRIMS), Applications System Verification and Transfer (ASVT), Remote Sensing Information Subsystem (RSIS): Acceptance test procedures
There are no author-identified significant results in this report
Living with the user: Design drama for dementia care through responsive scripted experiences in the home
Participation in forms of drama and narrative can provoke empathy and creativity in user-centred design processes. In this paper, we expand upon existing methods to explore the potential for responsive scripted experiences that are delivered through the combination of sensors and output devices placed in a home. The approach is being developed in the context of Dementia care, where the capacity for rich user participation in design activities is limited. In this case, a system can act as a proxy for a person with Dementia, allowing designers to gain experiences and insight as to what it is like to provide care for, and live with, this person. We describe the rationale behind the approach, a prototype system architecture, and our current work to explore the creation of scripted experiences for design, played out though UbiComp technologies.This research is funded by the Arts and Humanities Research Council UK, (AH/K00266X/1) and Horizon Digital Economy Research (RCUK grant EP/G065802/1)
Information sharing and credit : firm-level evidence from transition countries
We investigate whether information sharing among banks has affected credit market performance in the transition countries of Eastern Europe and the former Soviet Union, using a large sample of firm-level data. Our estimates show that information sharing is associated with improved availability and lower cost of credit to firms. This correlation is stronger for opaque firms than transparent ones and stronger in countries with weak legal environments than in those with strong legal environments. In cross-sectional estimates, we control for variation in country-level aggregate variables that may affect credit, by examining the differential impact of information sharing across firm types. In panel estimates, we also control for the presence of unobserved heterogeneity at the firm level, as well as for changes in macroeconomic variables and the legal environment
The stress-energy tensor for trans-Planckian cosmology
This article presents the derivation of the stress-energy tensor of a free
scalar field with a general non-linear dispersion relation in curved spacetime.
This dispersion relation is used as a phenomelogical description of the short
distance structure of spacetime following the conventional approach of
trans-Planckian modes in black hole physics and in cosmology. This
stress-energy tensor is then used to discuss both the equation of state of
trans-Planckian modes in cosmology and the magnitude of their backreaction
during inflation. It is shown that gravitational waves of trans-Planckian
momenta but subhorizon frequencies cannot account for the form of cosmic vacuum
energy density observed at present, contrary to a recent claim. The
backreaction effects during inflation are confirmed to be important and generic
for those dispersion relations that are liable to induce changes in the power
spectrum of metric fluctuations. Finally, it is shown that in pure de Sitter
inflation there is no modification of the power spectrum except for a possible
magnification of its overall amplitude independently of the dispersion
relation.Comment: 18 pages, 2 figures. Version to appear in PRD (minor modifications
Choosing more mathematics : happiness through work?
This paper examines how A-level students construct relationships between work and happiness in their accounts of choosing mathematics and further mathematics A-level. I develop a theoretical framework that positions work and happiness as opposed, managed and working on the self and use this to examine students' dual engagement with individual practices of the self and institutional practices of school mathematics. Interviews with students acknowledge four imperatives that they use as discursive resources to position themselves as successful/unsuccessful students: you have to work, you have to not work, you have to be happy, you have to work at being happy. Tensions in these positions lead students to rework their identities or drop further mathematics. I then identify the practices of mathematics teaching that students use to explain un/happiness in work, and show how dependable mathematics and working together are constructed as 'happy objects' for students, who develop strategies for claiming control over these shapers of happiness. © 2010 British Society for Research into Learning Mathematics
Zone center phonons of the orthorhombic RMnO3 (R = Pr, Eu, Tb, Dy, Ho) perovskites
A short range force constant model (SRFCM) has been applied for the first
time to investigate the phonons in RMnO3 (R = Pr, Eu, Tb, Dy, Ho) perovskites
in their orthorhombic phase. The calculations with 17 stretching and bending
force constants provide good agreement for the observed Raman frequencies. The
infrared frequencies have been assigned for the first time.
PACS Codes: 36.20.Ng, 33.20.Fb, 34.20.CfComment: 8 pages, 1 figur
Trans-Planckian Physics and the Spectrum of Fluctuations in a Bouncing Universe
In this paper, we calculate the spectrum of scalar field fluctuations in a
bouncing, asymptotically flat Universe, and investigate the dependence of the
result on changes in the physics on length scales shorter than the Planck
length which are introduced via modifications of the dispersion relation. In
this model, there are no ambiguities concerning the choice of the initial
vacuum state. We study an example in which the final spectrum of fluctuations
depends sensitively on the modifications of the dispersion relation without
needing to invoke complex frequencies. Changes in the amplitude and in the
spectral index are possible, in addition to modulations of the spectrum. This
strengthens the conclusions of previous work in which the spectrum of
cosmological perturbations in expanding inflationary cosmologies was studied,
and it was found that, for dispersion relations for which the evolution is not
adiabatic, the spectrum changes from the standard prediction of
scale-invariance.Comment: 10 pages, 6 figures, RevTeX4. Analytical determination of the
spectrum, corrected some typos, conclusions unchange
On Signatures of Short Distance Physics in the Cosmic Microwave Background
Following a self-contained review of the basics of the theory of cosmological
perturbations, we discuss why the conclusions reached in the recent paper by
Kaloper et al are too pessimistic estimates of the amplitude of possible
imprints of trans-Planckian (string) physics on the spectrum of cosmic
microwave anisotropies in an inflationary Universe. It is shown that the likely
origin of large trans-Planckian effects on late time cosmological fluctuations
comes from nonadiabatic evolution of the state of fluctuations while the
wavelength is smaller than the Planck (string) scale, resulting in an excited
state at the time that the wavelength crosses the Hubble radius during
inflation.Comment: 11 pages, 4 figure
Inferential models: A framework for prior-free posterior probabilistic inference
Posterior probabilistic statistical inference without priors is an important
but so far elusive goal. Fisher's fiducial inference, Dempster-Shafer theory of
belief functions, and Bayesian inference with default priors are attempts to
achieve this goal but, to date, none has given a completely satisfactory
picture. This paper presents a new framework for probabilistic inference, based
on inferential models (IMs), which not only provides data-dependent
probabilistic measures of uncertainty about the unknown parameter, but does so
with an automatic long-run frequency calibration property. The key to this new
approach is the identification of an unobservable auxiliary variable associated
with observable data and unknown parameter, and the prediction of this
auxiliary variable with a random set before conditioning on data. Here we
present a three-step IM construction, and prove a frequency-calibration
property of the IM's belief function under mild conditions. A corresponding
optimality theory is developed, which helps to resolve the non-uniqueness
issue. Several examples are presented to illustrate this new approach.Comment: 29 pages with 3 figures. Main text is the same as the published
version. Appendix B is an addition, not in the published version, that
contains some corrections and extensions of two of the main theorem
Topcolor assisted technicolor models and muon anomalous magnetic moment
We discuss and estimate the contributions of the new particles predicted by
topcolor assisted technicolor(TC2) models to the muon anomalous magnetic moment
. Our results show that the contributions of Pseudo Goldstone bosons
are very small which can be safely ignored. The main contributions come from
the ETC gauge boson and topcolor gauge boson . If we
demand that the mass of is consistent with other experimental
constrains, its contributions are smaller than that of . With
reasonable values of the parameters in TC2 models, the observed BNL results for
could be explained.Comment: latex file, 11 pages, several figures and references adde
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