477 research outputs found
Three fermions with six single particle states can be entangled in two inequivalent ways
Using a generalization of Cayley's hyperdeterminant as a new measure of
tripartite fermionic entanglement we obtain the SLOCC classification of
three-fermion systems with six single particle states. A special subclass of
such three-fermion systems is shown to have the same properties as the
well-known three-qubit ones. Our results can be presented in a unified way
using Freudenthal triple systems based on cubic Jordan algebras. For systems
with an arbitrary number of fermions and single particle states we propose the
Pl\"ucker relations as a sufficient and necessary condition of separability.Comment: 23 pages LATE
Assessing the potential of autonomous submarine gliders for ecosystem monitoring across multiple trophic levels (plankton to cetaceans) and pollutants in shallow shelf seas
A combination of scientific, economic, technological and policy drivers is behind a recent upsurge in the use of marine autonomous systems (and accompanying miniaturized sensors) for environmental mapping and monitoring. Increased spatial–temporal resolution and coverage of data, at reduced cost, is particularly vital for effective spatial management of highly dynamic and heterogeneous shelf environments. This proof-of-concept study involves integration of a novel combination of sensors onto buoyancy-driven submarine gliders, in order to assess their suitability for ecosystem monitoring in shelf waters at a variety of trophic levels. Two shallow-water Slocum gliders were equipped with CTD and fluorometer to measure physical properties and chlorophyll, respectively. One glider was also equipped with a single-frequency echosounder to collect information on zooplankton and fish distribution. The other glider carried a Passive Acoustic Monitoring system to detect and record cetacean vocalizations, and a passive sampler to detect chemical contaminants in the water column. The two gliders were deployed together off southwest UK in autumn 2013, and targeted a known tidal-mixing front west of the Isles of Scilly. The gliders’ mission took about 40 days, with each glider travelling distances of >1000 km and undertaking >2500 dives to depths of up to 100 m. Controlling glider flight and alignment of the two glider trajectories proved to be particularly challenging due to strong tidal flows. However, the gliders continued to collect data in poor weather when an accompanying research vessel was unable to operate. In addition, all glider sensors generated useful data, with particularly interesting initial results relating to subsurface chlorophyll maxima and numerous fish/cetacean detections within the water column. The broader implications of this study for marine ecosystem monitoring with submarine gliders are discussed
Factors affecting hotel selection: Greek customers' perception
Selection of hotel is of high priority and significance for tourists and entails a complicated decision-making process. The paper aims at identifying the most significant hotel selection factors taken into account by Greek customers. An empirical research study was conducted using an online survey. Ten factors identified by literature review included in the investigation. The findings indicate that Cleanliness is the most important factor in the selection of accommodation, followed by Price and Staff. Considering the priorities of tourists, hotel managers may design more effectively their segmentation, targeting and positioning strategy to ensure that their offerings match the needs and wants of their guests
Factors affecting hotel selection: Greek customers' perception
Selection of hotel is of high priority and significance for tourists and entails a complicated decision-making process. The paper aims at identifying the most significant hotel selection factors taken into account by Greek customers. An empirical research study was conducted using an online survey. Ten factors identified by literature review included in the investigation. The findings indicate that Cleanliness is the most important factor in the selection of accommodation, followed by Price and Staff. Considering the priorities of tourists, hotel managers may design more effectively their segmentation, targeting and positioning strategy to ensure that their offerings match the needs and wants of their guests
Kaon photoproduction: background contributions, form factors and missing resonances
The photoproduction p(gamma, K+)Lambda process is studied within a
field-theoretic approach. It is shown that the background contributions
constitute an important part of the reaction dynamics. We compare predictions
obtained with three plausible techniques for dealing with these background
contributions. It appears that the extracted resonance parameters drastically
depend on the applied technique. We investigate the implications of the
corrections to the functional form of the hadronic form factor in the contact
term, recently suggested by Davidson and Workman (Phys. Rev. C 63, 025210). The
role of background contributions and hadronic form factors for the
identification of the quantum numbers of ``missing'' resonances is discussed.Comment: 11 pages, 7 eps figures, submitted to Phys. Rev.
Spectrum and Variability of Mrk501 as observed by the CAT Imaging Telescope
The CAT Imaging Telescope has observed the BL Lac object Markarian 501
between March and August 1997. We report here on the variability over this time
including several large flares. We present also preliminary spectra for all
these data, for the low emission state, and for the largest flare.Comment: 4 pages, 4 figures, Late
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