79,524 research outputs found
Adapting to climate change in Europe and Central Asia: background paper on water supply and sanitation
Hearing loss: theoretical absence and visual bullying
The origins of Anglophone cultural theory in the mid-twentieth century were predominantly scopocentric, partly because of its epistemological history, and for the
cognate reason that visual tropes are so deeply embedded in the English language. As this scopocentricity comprehensively colonised cultural research, studies of nonvisual practices and texts were both marginalised and deformed. The discipline of film studies was dominated by attention to visual theoretical models, centred for
example on “the gaze”. Studies of film sound have burgeoned in recent times, but often have been hobbled by inappropriately scopic theoretical models, or they have
eschewed these models by withdrawing into more purely empirical approaches, such as genre studies or atomised “case studies”. While disclosing what E.P. Thompson called “the poverty of theory”, such studies have often found themselves in a conceptual no-man’s land. Without proposing a return to theoretical “master narratives” which compromise the integrity of the text, we argue that studies of film
sound should build on the work of scholars like Philip Tagg to develop further theoretical modelling based on the specificity of sound and its deployment in film
Selfadjoint and sectorial extensions of Sturm-Liouville operators
The self-adjoint and -sectorial extensions of coercive Sturm-Liouville
operators are characterised, under minimal smoothness conditions on the
coefficients of the differential expression.Comment: accepted by IEOT, in IEOT 201
Conserved mass models with stickiness and chipping
We study a chipping model in one dimensional periodic lattice with continuous
mass, where a fixed fraction of the mass is chipped off from a site and
distributed randomly among the departure site and its neighbours; the remaining
mass sticks to the site. In the asymmetric version, the chipped off mass is
distributed among the site and the right neighbour, whereas in the symmetric
version the redistribution occurs among the two neighbours. The steady state
mass distribution of the model is obtained using a perturbation method for both
parallel and random sequential updates. In most cases, this perturbation theory
provides a steady state distribution with reasonable accuracy.Comment: 17 pages, 4 eps figure
Spontaneous Symmetry Breaking in a Non-Conserving Two-Species Driven Model
A two species particle model on an open chain with dynamics which is
non-conserving in the bulk is introduced. The dynamical rules which define the
model obey a symmetry between the two species. The model exhibits a rich
behavior which includes spontaneous symmetry breaking and localized shocks. The
phase diagram in several regions of parameter space is calculated within
mean-field approximation, and compared with Monte-Carlo simulations. In the
limit where fluctuations in the number of particles in the system are taken to
zero, an exact solution is obtained. We present and analyze a physical picture
which serves to explain the different phases of the model
Spacetime Supersymmetry in a nontrivial NS-NS Superstring Background
In this paper we consider superstring propagation in a nontrivial NS-NS
background. We deform the world sheet stress tensor and supercurrent with an
infinitesimal B_{\mu\nu} field. We construct the gauge-covariant super-Poincare
generators in this background and show that the B_{\mu\nu} field spontaneously
breaks spacetime supersymmetry. We find that the gauge-covariant spacetime
momenta cease to commute with each other and with the spacetime supercharges.
We construct a set of "magnetic" super-Poincare generators that are conserved
for constant field strength H_{\mu\nu\lambda}, and show that these generators
obey a "magnetic" extension of the ordinary supersymmetry algebra.Comment: 13 pages, Latex. Published versio
Exact solution of the zero-range process: fundamental diagram of the corresponding exclusion process
In this paper, we propose a general way of computing expectation values in
the zero-range process, using an exact form of the partition function. As an
example, we provide the fundamental diagram (the flux-density plot) of the
asymmetric exclusion process corresponding to the zero-range process.We express
the partition function for the steady state by the Lauricella hypergeometric
function, and thereby have two exact fundamental diagrams each for the parallel
and random sequential update rules. Meanwhile, from the viewpoint of
equilibrium statistical mechanics, we work within the canonical ensemble but
the result obtained is certainly in agreement with previous works done in the
grand canonical ensemble.Comment: 12 pages, 2 figure
Pair-factorized steady states on arbitrary graphs
Stochastic mass transport models are usually described by specifying hopping
rates of particles between sites of a given lattice, and the goal is to predict
the existence and properties of the steady state. Here we ask the reverse
question: given a stationary state that factorizes over links (pairs of sites)
of an arbitrary connected graph, what are possible hopping rates that converge
to this state? We define a class of hopping functions which lead to the same
steady state and guarantee current conservation but may differ by the induced
current strength. For the special case of anisotropic hopping in two dimensions
we discuss some aspects of the phase structure. We also show how this case can
be traced back to an effective zero-range process in one dimension which is
solvable for a large class of hopping functions.Comment: IOP style, 9 pages, 1 figur
Development of fuel cell electrodes Semiannual report, 30 Jun. 1966 - 30 Dec. 1966
Fuel cell using circulating liquid electrolyte and water removal by transpiration through porous electrode
Phase Transition in the ABC Model
Recent studies have shown that one-dimensional driven systems can exhibit
phase separation even if the dynamics is governed by local rules. The ABC
model, which comprises three particle species that diffuse asymmetrically
around a ring, shows anomalous coarsening into a phase separated steady state.
In the limiting case in which the dynamics is symmetric and the parameter
describing the asymmetry tends to one, no phase separation occurs and the
steady state of the system is disordered. In the present work we consider the
weak asymmetry regime where is the system size and
study how the disordered state is approached. In the case of equal densities,
we find that the system exhibits a second order phase transition at some
nonzero .
The value of and the optimal profiles can be
obtained by writing the exact large deviation functional. For nonequal
densities, we write down mean field equations and analyze some of their
predictions.Comment: 18 pages, 3 figure
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