60,004 research outputs found
Private languages and private theorists
Simon Blackburn objects that Wittgenstein's private language argument overlooks the possibility that a private linguist can equip himself with a criterion of correctness by confirming generalizations about the patterns in which his private sensations occur. Crispin Wright responds that appropriate generalizations would be too few to be interesting. But I show that Wright's calculations are upset by his failure to appreciate both the richness of the data and the range of theories that would be available to the private linguist
Recognising Desire: A psychosocial approach to understanding education policy implementation and effect
It is argued that in order to understand the ways in which teachers experience their work - including the idiosyncratic ways in which they respond to and implement mandated education policy - it is necessary to take account both of sociological and of psychological issues. The paper draws on original research with practising and beginning teachers, and on theories of social and psychic induction, to illustrate the potential benefits of this bipartisan approach for both teachers and researchers. Recognising the significance of (but somewhat arbitrary distinction between) structure and agency in teachers’ practical and ideological positionings, it is suggested that teachers’ responses to local and central policy changes are governed by a mix of pragmatism, social determinism and often hidden desires. It is the often underacknowledged strength of desire that may tip teachers into accepting and implementing policies with which they are not ideologically comfortable
Unified model for vortex-string network evolution
We describe and numerically test the velocity-dependent one-scale (VOS)
string evolution model, a simple analytic approach describing a string network
with the averaged correlation length and velocity. We show that it accurately
reproduces the large-scale behaviour (in particular the scaling laws) of
numerical simulations of both Goto-Nambu and field theory string networks. We
explicitly demonstrate the relation between the high-energy physics approach
and the damped and non-relativistic limits which are relevant for condensed
matter physics. We also reproduce experimental results in this context and show
that the vortex-string density is significantly reduced by loop production, an
effect not included in the usual `coarse-grained' approach.Comment: 5 pages; v2: cosmetic changes, version to appear in PR
Mechanism for the failure of the Edwards hypothesis in the SK spin glass
The dynamics of the SK model at T=0 starting from random spin configurations
is considered. The metastable states reached by such dynamics are atypical of
such states as a whole, in that the probability density of site energies,
, is small at . Since virtually all metastable states
have a much larger , this behavior demonstrates a qualitative failure of
the Edwards hypothesis. We look for its origins by modelling the changes in the
site energies during the dynamics as a Markov process. We show how the small
arises from features of the Markov process that have a clear physical
basis in the spin-glass, and hence explain the failure of the Edwards
hypothesis.Comment: 5 pages, new title, modified text, additional reference
The Near-Infrared Extinction Law in Regions of High Av
We present a spectroscopic study of the shape of the dust-extinction law
between 1.0 and 2.2um towards a set of nine ultracompact HII regions with Av >
15 mag. We find some evidence that the reddening curve may tend to flatten at
higher extinctions, but just over half of the sample has extinction consistent
with or close to the average for the interstellar medium. There is no evidence
of extinction curves significantly steeper than the standard law, even where
water ice is present. Comparing the results to the predictions of a simple
extinction model, we suggest that a standard extinction law implies a robust
upper limit to the grain-size distribution at around 0.1 - 0.3um. Flatter
curves are most likely due to changes in this upper limit, although the effects
of flattening due to unresolved clumpy extinction cannot be ruled out.Comment: 9 pages, 7 figure
The Renal Lymphatics - an Important Fluid Transport System
Study of renal lymph fluid transport syste
Speech-plans: Generating evaluative responses in spoken dialogue
Recent work on evaluation of spoken dialogue systems indicates that better algorithms are needed for the presentation of complex information in speech. Current dialogue systems often rely on presenting sets of options and their attributes sequentially. This places a large memory burden on users, who have to remember complex trade-offs between multiple options and their attributes. To address these problems we build on previous work using multiattribute decision theory to devise speech-planning algorithms that present usertailored summaries, comparisons and recommendations that allow users to focus on critical differences between options and their attributes. We discuss the differences between speech and text planning that result from the particular demands of the speech situation.
Using post-measurement information in state discrimination
We consider a special form of state discrimination in which after the
measurement we are given additional information that may help us identify the
state. This task plays a central role in the analysis of quantum cryptographic
protocols in the noisy-storage model, where the identity of the state
corresponds to a certain bit string, and the additional information is
typically a choice of encoding that is initially unknown to the cheating party.
We first provide simple optimality conditions for measurements for any such
problem, and show upper and lower bounds on the success probability. For a
certain class of problems, we furthermore provide tight bounds on how useful
post-measurement information can be. In particular, we show that for this class
finding the optimal measurement for the task of state discrimination with
post-measurement information does in fact reduce to solving a different problem
of state discrimination without such information. However, we show that for the
corresponding classical state discrimination problems with post-measurement
information such a reduction is impossible, by relating the success probability
to the violation of Bell inequalities. This suggests the usefulness of
post-measurement information as another feature that distinguishes the
classical from a quantum world.Comment: 10 pages, 4 figures, revtex, v2: published version, minor change
Interface energies in Ising spin glasses
The replica method has been used to calculate the interface free energy
associated with the change from periodic to anti-periodic boundary conditions
in finite-dimensional spin glasses. At mean-field level the interface free
energy vanishes but after allowing for fluctuation effects, a non-zero
interface free energy is obtained which is significantly different from
numerical expectations.Comment: 4 pages. Minor changes and clarification
- …