5,279 research outputs found
Taylorism, targets and the pursuit of quantity and quality by call centre management
The paper locates the rise of the call centre within the context of the development of Taylorist methods and technological change in office work in general. Managerial utilisation of targets to impose and measure employees' quantitative and qualitative performance is analysed in four case-study organisations. The paper concludes that call centre work reflects a pardigmic re-configuration of customer servicing operations, and that the continuing application of Taylorist methods appears likely
Self Running Droplet: Emergence of Regular Motion from Nonequilibrium Noise
Spontaneous motion of an oil droplet driven by chemical nonequilibricity is
reported. It is shown that the droplet undergoes regular rhythmic motion under
appropriately designed boundary conditions, whereas it exhibits random motion
in an isotropic environment. This study is a novel manifestation on the direct
energy transformation of chemical energy into regular spatial-motion under
isothermal conditions. A simple mathematical equation including noise
reproduces the essential feature of the transition from irregularity into
periodic regular motion. Our results will inspire the theoretical study on the
mechanism of molecular motors in living matter, working under significant
influence of thermal fluctuation.Comment: 4 pages, 4 figure
The effect of pedunculopontine nucleus deep brain stimulation on postural sway and vestibular perception
© 2016 The Authors. European Journal of Neurology published by John Wiley & Sons Ltd on behalf of Europe an Academy of Neurology. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and re production in any medium, provided the original work is properly cited, see https://creativecommons.org/licenses/by/3.0/BACKGROUND AND PURPOSE: Deep brain stimulation (DBS) of the pedunculopontine nucleus (PPN) reduces the number of falls in patients with Parkinson's disease (PD). It was hypothesized that enhanced sensory processing contributes to this PPN-mediated gait improvement. METHODS: Four PD patients (and eight matched controls) with implanted bilateral PPN and subthalamic nucleus DBS electrodes were assessed on postural (with/without vision) and vestibular perceptual threshold tasks. RESULTS: Pedunculopontine nucleus ON stimulation (compared to OFF) lowered vestibular perceptual thresholds but there was a disproportionate increase in the normal sway increase on going from light to dark. CONCLUSIONS: The disproportionate increased sway with PPN stimulation in the dark may paradoxically improve balance function since mechanoreceptor signals rapidly adapt to continuous pressure stimulation from postural akinesia. Additionally, the PPN-mediated vestibular signal enhancement also improves the monitoring of postural sway. Overall, PPN stimulation may improve sensory feedback and hence balance performance.Peer reviewedFinal Published versio
Commercials, careers and culture: travelling salesmen in Britain 1890s-1930s
Within the lower middle-class, British commercial travellers established a strong fraternal culture before 1914. This article examines their interwar experiences in terms of income, careers, and associational culture. It demonstrates how internal labour markets operated, identifies the ways in which commercial travellers interpreted their role, and explores their social and political attitudes
A Note on D-brane - Anti-D-brane Interactions in Plane Wave Backgrounds
We study aspects of the interaction between a D-brane and an anti-D-brane in
the maximally supersymmetric plane wave background of type IIB superstring
theory, which is equipped with a mass parameter mu. An early such study in flat
spacetime (mu=0) served to sharpen intuition about D-brane interactions,
showing in particular the key role of the ``stringy halo'' that surrounds a
D-brane. The halo marks the edge of the region within which tachyon
condensation occurs, opening a gateway to new non-trivial vacua of the theory.
It seems pertinent to study the fate of the halo for non--zero mu. We focus on
the simplest cases of a Lorentzian brane with p=1 and an Euclidean brane with
p=-1, the D--instanton. For the Lorentzian brane, we observe that the halo is
unaffected by the presence of non--zero mu. This most likely extends to other
(Lorentzian) p. For the Euclidean brane, we find that the halo is affected by
non-zero mu. As this is related to subtleties in defining the exchange
amplitude between Euclidean branes in the open string sector, we expect this to
extend to all Euclidean branes in this background.Comment: 14 pages, LaTeX, 2 eps figures. v2: a reference and some clarifying
remarks added; v3: Considerably revised version; halo unaffected by plane
wave background for Lorentzian branes, but Euclidean branes' halo is modifie
On d=4,5,6 Vacua with 8 Supercharges
We show how all known N=2, d=4,5,6 maximally supersymmetric vacua (Hpp-waves
and aDSxS solutions) are related through dimensional reduction/oxidation
preserving all the unbroken supersymmetries. In particular we show how the N=2,
d=5 family of vacua (which are the near-horizon geometry of supersymmetric
rotating black holes) interpolates between aDS_2xS^3 and aDS_3xS^2 in parameter
space and how it can be dimensionally reduced to an N=2, d=4 dyonic
Robinson-Bertotti solution with geometry aDS_2xS^2 and oxidized to an N=2, d=6
solution with aDS_3xS^3 geometry (which is the near-horizon of the self-dual
string).Comment: Latex2e, 19 pages, 1 figure. v2: typos corrected, refs. added. v3:
very minor corrections, more refs. added, version to be published in
Classical and Quantum Gravit
p-branes on the waves
We present a large family of simple, explicit ten-dimensional supergravity
solutions describing extended extremal supersymmetric Ramond-Ramond p-branes
embedded into time-dependent dilaton-gravity plane waves of an arbitrary
(isotropic) profile, with the brane world-volume aligned parallel to the
propagation direction of the wave. Generalizations to the non-extremal case are
not analyzed explicitly, but can be pursued as indicated.Comment: 11 pages; v.2 minor notation changes, minor typos corrected
(published version
Strings on type IIB pp-wave backgrounds with interacting massive theories on the worldsheet
We consider superstring theories on pp-wave backgrounds which result in an
integrable supersymmetric Landau-Ginzburg theory on the
worldsheet. We obtain exact eigenvalues of the light-cone gauge superstring
hamiltonian in the massive and interacting world-sheet theory with
superpotential . We find the modes of the supergravity part of the
string spectrum, and their space-time interpretation. Because the system is
effectively at strong coupling on the worldsheet, these modes are not in
one-to-one correspondence with the usual type IIB supergravity modes in the
limit. However, the above correspondence holds in the limit.Comment: 20 pages, 1 figure; minor changes, comments adde
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