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A Theory of Dynamic Selective Vigilance and Preference Reversal, Based on the Example of New Coke
A neural network theory of preference reversal is presented. This theory includes a model of why New Coke was preferred to Old Coke on taste tests but was unpopular in the market. The model uses competing drive lod representing "excitement" and "security." Context influences which drive wins the competition, hence, which stimulus attributes are attended to. Our network's design, outlined m stages, is based on Grossberg's gated dipole theory. Three sets of dipoles, representing attributes, categories, and drives, are connected by modifiable associative synapses. The network also includes competition among categories and enhancement oi attention by mismatch of expectation
Direct observation of domain wall structures in curved permalloy wires containing an antinotch
The formation and field response of head-to-head domain walls in curved permalloy wires, fabricated to contain a single antinotch, have been investigated using Lorentz microscopy. High spatial resolution maps of the vector induction distribution in domain walls close to the antinotch have been derived and compared with micromagnetic simulations. In wires of 10 nm thickness the walls are typically of a modified asymmetric transverse wall type. Their response to applied fields tangential to the wire at the antinotch location was studied. The way the wall structure changes depends on whether the field moves the wall away from or further into the notch. Higher fields are needed and much more distorted wall structures are observed in the latter case, indicating that the antinotch acts as an energy barrier for the domain wal
Multiple Transitions to Chaos in a Damped Parametrically Forced Pendulum
We study bifurcations associated with stability of the lowest stationary
point (SP) of a damped parametrically forced pendulum by varying
(the natural frequency of the pendulum) and (the amplitude of the external
driving force). As is increased, the SP will restabilize after its
instability, destabilize again, and so {\it ad infinitum} for any given
. Its destabilizations (restabilizations) occur via alternating
supercritical (subcritical) period-doubling bifurcations (PDB's) and pitchfork
bifurcations, except the first destabilization at which a supercritical or
subcritical bifurcation takes place depending on the value of . For
each case of the supercritical destabilizations, an infinite sequence of PDB's
follows and leads to chaos. Consequently, an infinite series of period-doubling
transitions to chaos appears with increasing . The critical behaviors at the
transition points are also discussed.Comment: 20 pages + 7 figures (available upon request), RevTex 3.
Direct current control of three magnon scattering processes in spin-valve nanocontacts
We have investigated the generation of spin waves in the free layer of an
extended spin-valve structure with a nano-scaled point contact driven by both
microwave and direct electric current using Brillouin light scattering
microscopy. Simultaneously with the directly excited spin waves, strong
nonlinear effects are observed, namely the generation of eigenmodes with
integer multiple frequencies (2 \emph{f}, 3 \emph{f}, 4 \emph{f}) and modes
with non-integer factors (0.5 \emph{f}, 1.5 \emph{f}) with respect to the
excitation frequency \emph{f}. The origin of these nonlinear modes is traced
back to three magnon scattering processes. The direct current influence on the
generation of the fundamental mode at frequency \emph{f} can be related to the
spin-transfer torque, while the efficiency of three-magnon-scattering processes
is controlled by the Oersted field as an additional effect of the direct
current
On the computation of zone and double zone diagrams
Classical objects in computational geometry are defined by explicit
relations. Several years ago the pioneering works of T. Asano, J. Matousek and
T. Tokuyama introduced "implicit computational geometry", in which the
geometric objects are defined by implicit relations involving sets. An
important member in this family is called "a zone diagram". The implicit nature
of zone diagrams implies, as already observed in the original works, that their
computation is a challenging task. In a continuous setting this task has been
addressed (briefly) only by these authors in the Euclidean plane with point
sites. We discuss the possibility to compute zone diagrams in a wide class of
spaces and also shed new light on their computation in the original setting.
The class of spaces, which is introduced here, includes, in particular,
Euclidean spheres and finite dimensional strictly convex normed spaces. Sites
of a general form are allowed and it is shown that a generalization of the
iterative method suggested by Asano, Matousek and Tokuyama converges to a
double zone diagram, another implicit geometric object whose existence is known
in general. Occasionally a zone diagram can be obtained from this procedure.
The actual (approximate) computation of the iterations is based on a simple
algorithm which enables the approximate computation of Voronoi diagrams in a
general setting. Our analysis also yields a few byproducts of independent
interest, such as certain topological properties of Voronoi cells (e.g., that
in the considered setting their boundaries cannot be "fat").Comment: Very slight improvements (mainly correction of a few typos); add DOI;
Ref [51] points to a freely available computer application which implements
the algorithms; to appear in Discrete & Computational Geometry (available
online
The health and well-being of children and young people who are looked after: Findings from a face-to-face survey in Glasgow
Evidence suggests children and young people who are looked after (LACYP) may have poorer health outcomes than children and young people in the general population, particularly in relation to mental health. This paper discusses findings from a survey of the health and well-being of LACYP in Glasgow. A structured questionnaire used in the 2010 Glasgow Schools Survey (GSS) was adapted and administered in face-to- face interviews with 130 young people aged 11â18 in 2014â2015 to investigate various aspects of health and well-being including physical activity, diet and sleep, smoking, alcohol and drugs, health feelings and worries, behaviours, attitudes and expectations. LACYP were more likely to report that they had tried drugs, slightly more likely to have scores indicating a high level of difficulties on the Strengths and Difficulties Questionnaire (SDQ) and less likely to report that they ate fruit and vegetables, used active transport methods to get to school and expected to go on to further or higher education; however, reported rates of physical activity, smoking and drinking were similar. LACYP were less likely to report that they had engaged in antisocial behaviour, truancy or bullying or been exposed to environmental tobacco smoke, less likely to worry or have low self-esteem, and more likely to rate their health positively. There were some variations according to placement type. The findings of this study present a more positive picture of the health and well-being of LACYP in Glasgow than might have been expected but should be treated with caution due to small sample size. Further research is needed to identify differences in relation to placement type and to determine whether being looked after might be associated with improved health and well-being outcomes for some children and young people
Mechanical design report of the barrel liquid argon presampler
The note describes the mechanical design of the Atlas barrel presampler and its evolution since the publication of thecalorimeter TDR in December 9
Stigma and Fear: the 'Psy Professional' in Cultural Artifacts
This is the author accepted manuscript. The final version is available from Wiley via the DOI in this record.The loss of reason called madness provokes perhaps the greatest human fear, for it is reason that
dignifies humanity and separates us from beasts. The âpsy professionalsâ - those who prescribe and
administer treatments for madness - are frequently portrayed in fiction, film, comics, computer
games and entertainments, along with the mad themselves and the asylums that confine them.
Overall, these depictions are malign: the reader/watcher/player is encouraged to fear the mad, the
madhouse and the mad-doctor. Choosing to use less abrasive vocabulary to name the condition of
madness makes no difference to the terror the condition arouses, for the content of many books and
games aims to inspire fear. In spite of considerable efforts over many years, the stigma which
attaches to mental illness remains firmly in place for patients, while psy professionals also carry their
share of âsome of the discredit of the stigmatizedâ (Goffman 1968, p 43) and join patients in a
stigmatized group. Popular belief often equates the psy professions with madness (Walter, 1989).
This paper explores ways in which the fear of madness, and the stigma which clings to sufferers and
their professional carers, is perpetuated by a constant stream of popular cultural artifacts
Chronic fatigue syndrome: identifying zebras amongst the horses
There are currently no investigative tools or physical signs that can confirm or refute the presence of chronic fatigue syndrome (CFS). As a result, clinicians must decide how long to keep looking for alternative explanations for fatigue before settling on a diagnosis of CFS. Too little investigation risks serious or easily treatable causes of fatigue being overlooked, whilst too many increases the risk of iatrogenic harm and reduces the opportunity for early focused treatment. A paper by Jones et al published this month in BMC Medicine may help clinicians in deciding how to undertake such investigations. Their results suggest that if clinicians look for common psychiatric and medical conditions in those complaining of prolonged fatigue, the rate of detection will be higher than previously estimated. The most common co-morbid condition identified was depression, suggesting a simple mental state examination remains the most productive single investigation in any new person presenting with unexplained fatigue. Currently, most diagnostic criteria advice CFS should not be diagnosed when an active medical or psychiatric condition which may explain the fatigue is identified. We discuss a number of recent prospective studies that have provided valuable insights into the aetiology of chronic fatigue and describe a model for understanding chronic fatigue which may be equally relevant regardless of whether or not an apparent medical cause for fatigue can be identified
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