17,351 research outputs found
The Segment Ontology: Bridging Music-generic and Domain-specific
Existing semantic representations of music analysis encapsulate narrow sub-domain concepts and are frequently scoped by the context of a particular MIR task. Segmentation is a crucial abstraction in the investigation of phenomena which unfold over time; we present a Segment Ontology as the backbone of an approach that models properties from the musicological domain independently from MIR implementations and their signal processing foundations, whilst maintaining an accurate and complete description of the relationships that link them. This framework provides two principal advantages which are explored through several examples: a layered separation of concerns that aligns the model with the needs of the users and systems that consume and produce the data; and the ability to link multiple analyses of differing types through transforms to and from the Segment axis
Aggregation without the aggravation? Nonparametric analysis of the representative consumer.
In the tradition of Afriat (1967), Diewert (1973) and Varian (1982), we provide a revealed preference characterisation of the representative consumer. Our results are simple and complement those of Gorman (1953, 1961), Samuelson (1956) and others. They can also be applied to data very readily and without the need for auxilliary parametric or statistical assumptions. We investigate the application of our characterisation by means of a balanced microdata panel survey. Our findings provide robust evidence against the existence of a representative consumer for our data.
Aggregation without the Aggravation? Nonparametric Analysis of the Representative Consumer
Abstract: In the tradition of Afriat (1967), Diewert (1973) and Varian (1982), we provide a revealed preference characterisation of the representative consumer. Our results are simple and complement those of Gorman (1953, 1961), Samuelson (1956) and others. They can also be applied to data very readily and without the need for auxilliary parametric or statistical assumptions. We investigate the application of our characterisation by means of a balanced microdata panel survey. Our findings provide robust evidence against the existence of a representative consumer for our data.revealed preference;aggregation;Gorman Polar Form;GARP
Aggregation without the aggravation? Nonparametric analysis of the representative consumer
In the tradition of Afriat (1967), Diewert (1973) and Varian (1982), we provide a revealed preference characterisation of the representative consumer. Our results are simple and complement those of Gorman (1953, 1961), Samuelson (1956) and others. They can also be applied to data very readily and without the need for auxiliary parametric or statistical assumptions. We investigate the application of our characterisation by means of a balanced microdata panel survey. Our findings provide robust evidence against the existence of a representative consumer for our data.
Aggregation without the Aggravation? Nonparametric Analysis of the Representative Consumer
In the tradition of Afriat (1967), Diewert (1973) and Varian (1982), we provide a revealed preference characterisation of the representative consumer. Our results are simple and complement those of Gorman (1953, 1961), Samuelson (1956) and others. They can also be applied to data very readily and without the need for auxilliary parametric or statistical assumptions. We investigate the application of our characterisation by means of a balanced microdata panel survey. Our findings provide robust evidence against the existence of a representative consumer for our data.revealed preference, aggregation, Gorman polar form, GARP
Modelling the effect of nuclear motion on the attosecond time-resolved photoelectron spectra of ethylene
Using time dependent density functional theory (TDDFT) we examine the energy,
angular and time-resolved photoelectron spectra (TRPES) of ethylene in a
pump-probe setup. To simulate TRPES we expose ethylene to an ultraviolet (UV)
femtosecond pump pulse, followed by a time delayed extreme ultraviolet (XUV)
probe pulse. Studying the photoemission spectra as a function of this delay
provides us direct access to the dynamic evolution of the molecule's electronic
levels. Further, by including the nuclei's motion, we provide direct chemical
insight into the chemical reactivity of ethylene. These results show how
angular and energy resolved TRPES could be used to directly probe electron and
nucleus dynamics in molecules.Comment: 9 pages, 6 figure
Quantum tomography for Dirac spinors
We present a tomographic scheme, based on spacetime symmetries, for the
reconstruction of the internal degrees of freedom of a Dirac spinor. We discuss
the circumstances under which the tomographic group can be taken as SU(2), and
how this crucially depends on the choice of the gamma matrix representation. A
tomographic reconstruction process based on discrete rotations is considered,
as well as a continuous alternative.Comment: 9 pages, LaTeX; v2: minor changes, references added. A slightly
revised version has been accepted for publication in Phys. Lett.
Interstellar reddening towards six small areas in Puppis-Vela
We investigate the distribution of the interstellar dust towards six small
volumes of the sky in the region of the Gum nebula. New high-quality
four-colour uvby and H\beta\ Str\"omgren photometry obtained for 352 stars in
six selected areas of Kapteyn, complemented with data obtained in a previous
investigation for two of these areas, were used to estimate the colour excess
and distance to these objects. The obtained colour excess versus distance
diagrams, complemented with other information, when available, were analysed in
order to infer the properties of the interstellar medium permeating the
observed volumes. On the basis of the overall standard deviation in the
photometric measurements, we estimate that colour excesses and distances are
determined with an accuracy of 0.010 mag and better than 30%, respectively, for
a sample of 520 stars. A comparison with 37 stars in common with the new
Hipparcos catalogue attests to the high quality of the photometric distance
determination. The obtained colour excess versus distance diagrams testify to
the low density volume towards the observed lines-of-sight. Very few stars out
to distances of 1 kpc from the Sun have colour excesses larger than E(b-y) =
0.1 mag. In spite of the low density character of the interstellar medium
towards the Puppis-Vela direction, the obtained reddening as a function of the
distance indicates that two or more interstellar structures are crossed towards
the observed lines-of-sight. One of these structures may be associated with the
very low density wall of the Local Cavity, which has a distance of 100-150 pc
from the Sun. Another structure might be related to the Gum nebula, and if so,
its front face would be located at about 350 pc from the Sun.Comment: Accepted by Astronomy and Astrophysic
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