14,196 research outputs found
Path, theme and narrative in open plan exhibition settings
Three arguments are made based on the analysis of science exhibitions. First,sufficiently refined techniques of spatial analysis allow us to model the impact oflayout upon visitors' paths, even in moderately sized open plans which allow almostrandom patterns of movement and relatively unobstructed visibility. Second, newlydeveloped or adapted techniques of analysis allow us to make a transition frommodeling the mechanics of spatial movement (the way in which movement is affectedby the distribution of obstacles and boundaries), to modeling the manner in whichmovement might register additional aspects of visual information. Third, theadvantages of such purely spatial modes of analysis extend into providing us with asharper understanding of some of the pragmatic constrains within which exhibitioncontent is conceived and designed
The CGLMP Bell Inequalities and Quantum Theory
Quantum non-locality tests have been of interest since the original EPR
paper. The present paper discusses whether the CGLMP (Bell) inequalities
obtained by Collins et al are possible tests for showing that quantum theory is
not underpinned by local hidden variable theory (LHVT). It is found by applying
Fine's theorem that the CGLMP approach involves a LHVT for the probabilities
associated with measurements on two observables (each from one of the two
sub-subsystems), even though the underlying probabilities for measurements of
all four observables involve a hidden variable theory which is not required to
be local. Although the CGLMP inequalities involve probabilities for
measurements of one observable per sub-system and are compatible with the
Heisenberg uncertainty principle, there is no unambiguous quantum measurement
process linked to the probabilities in the CGLMP inequalities. Quantum
measurements corresponding to the different classical measurements that give
the same CGLMP probability are found to yield different CGLMP probabilities.
However, violation of a CGLMP inequality based on any one of the possible
quantum measurement sequences is sufficient to show that the Collins et al LHVT
does not predict the same results as quantum theory. This is found to occur for
a state considered in their paper - though for observables whose physical
interpretation is unclear. In spite of the problems of comparing the HVT
inequalities with quantum expressions, it is concluded that the CGLMP
inequalities are indeed suitable for ruling out local hidden variable theories.
The state involved could apply to a macroscopic system, so the CGLMP Bell
inequalities are important for finding cases of macroscopic violations of Bell
locality. Possible experiments in double-well Bose condensates involving atoms
with two hyperfine components are discussed.Comment: 23 pages, 0 figures. Version 4. Significant revision of previous
version. Relation of CGLMP inequalities to local hidden variable theories
demonstrated via Fine's theore
Theory of decoherence in Bose-Einstein condensate interferometry
A full treatment of decoherence and dephasing effects in BEC interferometry
has been developed based on using quantum correlation functions for treating
interferometric effects. The BEC is described via a phase space distribution
functional of the Wigner type for the condensate modes and the positive P type
for the non-condensate modes. Ito equations for stochastic condensate and
non-condensate field functions replace the functional Fokker-Planck equation
for the distribution functional and stochastic averages of field function
products determine the quantum correlation functions.Comment: Proceedings DICE 06 Conference, 11-15 Sept 2006, Piombino, Ital
Theory of decoherence in Bose-Einstein condensate interferometry
A full treatment of decoherence and dephasing effects in BEC interferometry
has been developed based on using quantum correlation functions for treating
interferometric effects. The BEC is described via a phase space distribution
functional of the Wigner type for the condensate modes and the positive P type
for the non-condensate modes. Ito equations for stochastic condensate and
non-condensate field functions replace the functional Fokker-Planck equation
for the distribution functional and stochastic averages of field function
products determine the quantum correlation functions.Comment: Proceedings DICE 06 Conference, 11-15 Sept 2006, Piombino, Ital
Theory of decoherence in Bose-Einstein condensate interferometry
A full treatment of decoherence and dephasing effects in BEC interferometry
has been developed based on using quantum correlation functions for treating
interferometric effects. The BEC is described via a phase space distribution
functional of the Wigner type for the condensate modes and the positive P type
for the non-condensate modes. Ito equations for stochastic condensate and
non-condensate field functions replace the functional Fokker-Planck equation
for the distribution functional and stochastic averages of field function
products determine the quantum correlation functions.Comment: Proceedings DICE 06 Conference, 11-15 Sept 2006, Piombino, Ital
A HEDONIC MODEL OF RICE TRAITS: ECONOMIC VALUES FROM FARMERS IN WEST AFRICA
New crop varieties often have been promoted in developing countries based upon superior yield vis-a-vis locally available varieties. This research presents a hedonic model for upland rice by drawing upon the input characteristics and consumer good characteristics model literature. Model specification tests determine that a combination of production and consumption characteristics best explains the willingness to pay for new upland rice varieties. This non-separable household model specification determined that four traits explain the willingness to pay for new rice varieties: plant cycle length, plant height, grain elongation/swelling and tenderness. Yield was not significant explanatory variable for the willingness to pay for seed. The implications of this model are two-fold. First, varietal development and promotion must include post-harvest characteristics in addition to production traits when determining which varieties to promote for official release. Secondly, non-yield production characteristics such as plant height and cycle length are significant factors in producers' assessments of the value of a new variety. Overall, this paper provides an alternative explanation for limited adoption of modern upland rice varieties in West Africa: varietal evaluation programs have focused too narrowly on yield evaluation and have not promoted varieties with superior non-yield characteristics than locally available varieties.hedonic, upland rice, West Africa, household modelling, Crop Production/Industries,
Cascade atom in high-Q cavity: The spectrum for non-Markovian decay
The spontaneous emission spectrum for a three level cascade configuration
atom in a single mode high-Q cavity coupled to a zero temperature reservoir of
continuum external modes is determined from the atom-cavity mode master
equation using the quantum regression theorem. Initially the atom is in its
upper state and the cavity mode empty of photons. Following Glauber, the
spectrum is defined via the response of a detector atom. Spectra are calculated
for the detector located inside the cavity (case A), outside the cavity end
mirror (Case B-end emission), or placed for emission out the side of the cavity
(Case C). The spectra for case A and case B are found to be essentially the
same. In all the cases the predicted lineshapes are free of instrumental
effects and only due to cavity decay. Spectra are presented for intermediate
and strong coupling regime situations (where both atomic transitions are
resonant with the cavity frequency), for cases of non-zero cavity detuning, and
for cases where the two atomic transition frequencies differ. The spectral
features for Cases B(A) and C are qualitatively similar, with six spectral
peaks for resonance cases and eight for detuned cases. These general features
of the spectra can be understood via the dressed atom model. However, Case B
and C spectra differ in detail, with the latter exhibiting a deep spectral hole
at the cavity frequency due to quantum interference effects.Comment: 29 pages, 14 figures; v2: very minor correction to two equations,
thicker lines in some figure
Data registration and integration requirements for severe storms research
Severe storms research is characterized by temporal scales ranging from minutes (for thunderstorms and tornadoes) to hours (for hurricanes and extra-tropical cyclones). Spatial scales range from tens to hundreds of kilometers. Sources of observational data include a variety of ground based and satellite systems. Requirements for registration and intercomparison of data from these various sources are examined and the potential for operational forecasting application of techniques resulting from the research is discussed. The sensor characteristics and processing procedures relating to the overlay and integrated analysis of satellite and surface observations for severe storms research are reviewed
Configuration description and load analysis for the Atmospheric and Oceanographic Information Processing System (AOIPS)
A computer system for processing image data is described. It essentially consists of two minicomputer systems. System components are listed and discussed, and flow charts are shown
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