1,110 research outputs found
The unacknowledged legacy
This paper presents a critical discussion of the treatment of mimetic art, and particularly poetry and the theatre, in the work of the Athenian philosopher Plato (427-347 BC). It centres on Plato's discussion of the corrupting powers of the arts in the Republic, and the implications that his fierce attack on poetry and theatre have for his construction of the ideal polity. The legacy of Platonic ideas in later elaborations of the corrupting power of the arts is discussed. Furthermore, the paper investigates the relationship between current debates on cultural policy and the Platonic idea that the transformative powers of the arts ought to be harnessed by the state to promote a just society. The conclusion thus reached is that “instrumental cultural policy”, rather then being a modern invention, was in fact first theorized precisely in Plato's Republic
A field study of team working in a new human supervisory control system
This paper presents a case study of an investigation into team behaviour in an energy distribution company. The main aim was to investigate the impact of major changes in the company on system performance, comprising human and technical elements. A socio-technical systems approach was adopted. There were main differences between the teams investigated in the study: the time of year each control room was studied (i.e. summer or winter),the stage of development each team was in (i.e. 10 months), and the team structure (i.e. hierarchical or heterarchical). In all other respects the control rooms were the same: employing the same technology and within the same organization. The main findings were: the teams studied in the winter months were engaged in more `planning’ and `awareness’ type of activities than those studies in the summer months. Newer teams seem to be engaged in more sharing of information than older teams, which maybe indicative of the development process. One of the hierarchical teams was engaged in more `system-driven’ activities than the heterarchical team studied at the same time of year. Finally, in general, the heterarchical team perceived a greater degree of team working culture than its hierarchical counterparts. This applied research project confirms findings from laboratory research and emphasizes the importance of involving ergonomics in the design of team working in human supervisory control
Anomalously large oxygen-ordering contribution to the thermal expansion of untwinned YBa2Cu3O6.95 single crystals: a glass-like transition near room temperature
We present high-resolution capacitance dilatometry studies from 5 - 500 K of
untwinned YBa2Cu3Ox (Y123) single crystals for x ~ 6.95 and x = 7.0. Large
contributions to the thermal expansivities due to O-ordering are found for x ~
6.95, which disappear below a kinetic glass-like transition near room
temperature. The kinetics at this glass transition is governed by an energy
barrier of 0.98 +- 0.07 eV, in very good agreement with other O-ordering
studies. Using thermodynamic arguments, we show that O-ordering in the Y123
system is particularly sensitive to uniaxial pressure (stress) along the chain
axis and that the lack of well-ordered chains in Nd123 and La123 is most likely
a consequence of a chemical-pressure effect.Comment: 4 pages, 3 figures, submitted to PR
What determines the spreading of a wave packet?
The multifractal dimensions D2^mu and D2^psi of the energy spectrum and
eigenfunctions, resp., are shown to determine the asymptotic scaling of the
width of a spreading wave packet. For systems where the shape of the wave
packet is preserved the k-th moment increases as t^(k*beta) with
beta=D2^mu/D2^psi, while in general t^(k*beta) is an optimal lower bound.
Furthermore, we show that in d dimensions asymptotically in time the center of
any wave packet decreases spatially as a power law with exponent D_2^psi - d
and present numerical support for these results.Comment: Physical Review Letters to appear, 4 pages postscript with figure
Enhancement of Noise-induced Escape through the Existence of a Chaotic Saddle
We study the noise-induced escape process in a prototype dissipative
nonequilibrium system, the Ikeda map. In the presence of a chaotic saddle
embedded in the basin of attraction of the metastable state, we find the novel
phenomenon of a strong enhancement of noise-induced escape. This result is
established by employing the theory of quasipotentials. Our finding is of
general validity and should be experimentally observable.Comment: 4 page
Recommended from our members
The convective storm initiation project
Copyright @ 2007 AMSThe Convective Storm Initiation Project (CSIP) is an international project to understand precisely where, when, and how convective clouds form and develop into showers in the mainly maritime environment of southern England. A major aim of CSIP is to compare the results of the very high resolution Met Office weather forecasting model with detailed observations of the early stages of convective clouds and to use the newly gained understanding to improve the predictions of the model. A large array of ground-based instruments plus two instrumented aircraft, from the U.K. National Centre for Atmospheric Science (NCAS) and the German Institute for Meteorology and Climate Research (IMK), Karlsruhe, were deployed in southern England, over an area centered on the meteorological radars at Chilbolton, during the summers of 2004 and 2005. In addition to a variety of ground-based remote-sensing instruments, numerous rawin-sondes were released at one- to two-hourly intervals from six closely spaced sites. The Met Office weather radar network and Meteosat satellite imagery were used to provide context for the observations made by the instruments deployed during CSIP. This article presents an overview of the CSIP field campaign and examples from CSIP of the types of convective initiation phenomena that are typical in the United Kingdom. It shows the way in which certain kinds of observational data are able to reveal these phenomena and gives an explanation of how the analyses of data from the field campaign will be used in the development of an improved very high resolution NWP model for operational use.This work is funded by the National Environment Research Council following an initial award from the HEFCE Joint Infrastructure Fund
The electronic state of vortices in YBa2Cu3Oy investigated by complex surface impedance measurement
The electromagnetic response to microwaves in the mixed state of
YBa2Cu3Oy(YBCO) was measured in order to investigate the electronic state
inside and outside the vortex core. The magnetic-field dependence of the
complex surface impedance at low temperatures was in good agreement with a
general vortex dynamics description assuming that the field-independent viscous
damping force and the linear restoring force were acting on the vortices. In
other words, both real and imaginary parts of the complex resistivity, \rho_1,
and \rho_2, were linear in B. This is explained by theories for d-wave
superconductors. Using analysis based on the Coffey-Clem description of the
complex penetration depth, we estimated that the vortex viscosity \eta at 10 K
was (4 \sim 5) \times 10^{-7} Ns/m^2. This value corresponds to \omega_0 \tau
\sim 0.3 - 0.5, where \omega_0 and \tau are the minimal gap frequency and the
quasiparticle lifetime in the vortex core, respectively. These results suggest
that the vortex core in YBCO is in the moderately clean regime. Investigation
of the moderately clean vortex core in high-temperature superconductors is
significant because physically new effects may be expected due to d-wave
characteristics and to the quantum nature of cuprate superconductors. The
behavior of Z_s as a function of B across the first order transition (FOT) of
the vortex lattice was also investigated. Unlike Bi2Sr2CaCu2Oy (BSCCO), no
distinct anomaly was observed around the FOT in YBCO. Our results suggest that
the rapid increase of X_s due to the change of superfluid density at the FOT
would be observed only in highly anisotropic two-dimensional vortex systems
like BSCCO. We discuss these results in terms of the difference of the
interlayer coupling and the energy scale between the two materials.Comment: 10 pages, 6 figures, to be published in Phys. Rev. B, one reference
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Haemodynamic consequences of changing bicarbonate and calcium concentrations in haemodialysis fluids
Background. In a previous study we demonstrated that mild metabolic alkalosis resulting from standard bicarbonate haemodialysis induces hypotension. In this study, we have further investigated the changes in systemic haemodynamics induced by bicarbonate and calcium, using non-invasive procedures
Communities and patterns of scientific collaboration in Business and Management
This is the author's accepted version of this article deposited at arXiv (arXiv:1006.1788v2 [physics.soc-ph]) and subsequently published in Scientometrics October 2011, Volume 89, Issue 1, pp 381-396. The final publication is available at link.springer.com http://link.springer.com/article/10.1007%2Fs11192-011-0439-1Author's note: 17 pages. To appear in special edition of Scientometrics. Abstract on arXiv meta-data a shorter version of abstract on actual paper (both in journal and arXiv full pape
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