16,720 research outputs found
Enabling occupational therapy students to take a fresh approach to psychosis
This practice evaluation describes the implementation of a 2-day workshop on
psychosis with third-year undergraduate occupational therapy students at
Brunel University. The work was undertaken by the teaching team at Brunel
University, a clinical psychologist working in assertive outreach and an
occupational therapist working in community mental health. The background
to the project and the way in which the 2-day workshop was adapted to
accommodate the university timetable are outlined. An evaluation of the
workshop, its place in the occupational therapy programme and the feedback
from students are presented
Black holes, cosmological singularities and change of signature
There exists a widespread belief that signature type change could be used to
avoid spacetime singularities. We show that signature change cannot be utilised
to this end unless the Einstein equation is abandoned at the suface of
signature type change. We also discuss how to solve the initial value problem
and show to which extent smooth and discontinuous signature changing solutions
are equivalent.Comment: 14pages, Latex, no figur
Unified first law of black-hole dynamics and relativistic thermodynamics
A unified first law of black-hole dynamics and relativistic thermodynamics is
derived in spherically symmetric general relativity. This equation expresses
the gradient of the active gravitational energy E according to the Einstein
equation, divided into energy-supply and work terms. Projecting the equation
along the flow of thermodynamic matter and along the trapping horizon of a
blackhole yield, respectively, first laws of relativistic thermodynamics and
black-hole dynamics. In the black-hole case, this first law has the same form
as the first law of black-hole statics, with static perturbations replaced by
the derivative along the horizon. There is the expected term involving the area
and surface gravity, where the dynamic surface gravity is defined as in the
static case but using the Kodama vector and trapping horizon. This surface
gravity vanishes for degenerate trapping horizons and satisfies certain
expected inequalities involving the area and energy. In the thermodynamic case,
the quasi-local first law has the same form, apart from a relativistic factor,
as the classical first law of thermodynamics, involving heat supply and
hydrodynamic work, but with E replacing the internal energy. Expanding E in the
Newtonian limit shows that it incorporates the Newtonian mass, kinetic energy,
gravitational potential energy and thermal energy. There is also a weak type of
unified zeroth law: a Gibbs-like definition of thermal equilibrium requires
constancy of an effective temperature, generalising the Tolman condition and
the particular case of Hawking radiation, while gravithermal equilibrium
further requires constancy of surface gravity. Finally, it is suggested that
the energy operator of spherically symmetric quantum gravity is determined by
the Kodama vector, which encodes a dynamic time related to E.Comment: 18 pages, TeX, expanded somewhat, to appear in Class. Quantum Gra
Accurate angle-of-arrival measurement using particle swarm optimization
As one of the major methods for location positioning, angle-of-arrival (AOA) estimation is a significant technology in radar, sonar, radio astronomy, and mobile communications. AOA measurements can be exploited to locate mobile units, enhance communication efficiency and network capacity, and support location-aided routing, dynamic network management, and many location-based services. In this paper, we propose an algorithm for AOA estimation in colored noise fields and harsh application scenarios. By modeling the unknown noise covariance as a linear combination of known weighting matrices, a maximum likelihood (ML) criterion is established, and a particle swarm optimization (PSO) paradigm is designed to optimize the cost function. Simulation results demonstrate that the paired estimator PSO-ML significantly outperforms other popular techniques and produces superior AOA estimates
Angular momentum conservation for uniformly expanding flows
Angular momentum has recently been defined as a surface integral involving an
axial vector and a twist 1-form, which measures the twisting around of
space-time due to a rotating mass. The axial vector is chosen to be a
transverse, divergence-free, coordinate vector, which is compatible with any
initial choice of axis and integral curves. Then a conservation equation
expresses rate of change of angular momentum along a uniformly expanding flow
as a surface integral of angular momentum densities, with the same form as the
standard equation for an axial Killing vector, apart from the inclusion of an
effective energy tensor for gravitational radiation.Comment: 5 revtex4 pages, 3 eps figure
Cohort Survival Analysis is Not Enough: Why Local Planners Need to Know More About the Residential Mobility of the Elderly
The residential mobility choices of the elderly (aging-in-place, local moves, or migration) have very different policy implications forming a dynamic system of inter-related issues that present planners with a number of dilemmas which are particularly sensitive to local context. These include competing models of care and service delivery, provision of appropriate housing, physically and socially supportive local environments, community development, relocation services, housing specialization and age integration, the introduction of housing options within neighbourhoods, population redistribution, economic development, social integration, and localized differences in the demand for services. Local planners need to move beyond simple estimates of future demand based expected numbers and present use patterns, to examine the possible impact of these issues on the integration of an aging population within their communities.residential mobility; elderly; planning
Using fractals and power laws to predict the location of mineral deposits
Around the world the mineral exploration industry is interested in getting that small increase in probability measure on the earth's surface of where the next large undiscovered deposit might be found. In particular WMC Resources Ltd has operations world wide looking for just that edge in the detection of very large deposits of, for example, gold. Since the pioneering work of Mandelbrot, geologists have been familiar with the concept of fractals and self similarity over a few orders of magnitude for geological features. This includes the location and size of deposits within a particular mineral province. Fractal dimensions have been computed for such provinces and similarities of these aggregated measures between provinces have been noted. This paper explores the possibility of making use of known information to attempt the inverse process. That is, from lesser dimensional measures of a mineral province, for example, fractal dimension or more generally multi-fractal measures, is it possible to infer, even with small increase in probability, where the unknown (preferably large) deposits might be located
Instrumented transducer for study of the bat echolocation process
Evolution has enabled the bat to echolocate with ease and efficiency, to the extent that the bats capabilities far exceed the most technologically advanced manmade systems. Such capabilities reinforce mans intrigue in the animal kingdom. In studying bats we aspire to quantify and understand their inherent skills in the hope of transferring them to engineering systems. In trying to further our understanding of the animal kingdom it is often the case that we try to replicate or mimic what the animal is doing. In terms of echolocation it is thought that a bat emits a signal and retains memory of an exact copy to be used in conjunction with the returning echo to reveal information about the target. To emulate the vocalisation and auditory system of a bat it is necessary to both accurately generate and detect sound waves
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