24,509 research outputs found
FURY: Fuzzy unification and resolution based on edit distance
We present a theoretically founded framework for fuzzy
unification and resolution based on edit distance over trees.
Our framework extends classical unification and resolution
conservatively. We prove important properties of the framework
and develop the FURY system, which implements the
framework efficiently using dynamic programming. We
evaluate the framework and system on a large problem in
the bioinformatics domain, that of detecting typographical
errors in an enzyme name databas
A representational framework and user-interface for an image understanding workstation
Problems in image understanding involve a wide variety of data (e.g., image arrays, edge maps, 3-D shape models) and processes or algorithms (e.g., convolution, feature extraction, rendering). The underlying structure of an Image Understanding Workstation designed to support mulitple levels and types of representations for both data and processes is described, also the user-interface. The Image Understanding Workstation consists of two parts: the Image Understanding (IU) Framework, and the user-interface. The IU Framework is the set of data and process representations. It includes multiple levels of representation for data such as images (2-D), sketches (2-D), surfaces (2 1/2 D), and models (3-D). The representation scheme for processes characterizes their inputs, outputs, and parameters. Data and processes may reside on different classes of machines. The user-interface to the IU Workstation gives the user convenient access for creating, manipulating, transforming, and displaying image data. The user-interface follows the structure of the IU Framework and gives the user control over multiple types of data and processes. Both the IU Framework and user-interface are implemented on a LISP machine
Interactive visualisation and exploration of biological data
International audienceno abstrac
Biscayne aquifer in Dade and Broward Counties, Florida
The Biscayne Aquifer is the principal source of water for the heavily
populated area in the vicinity of West Palm Beach and Miami. The
publication of this data is timely and will assist in the intelligent development
of the water resources of the area.(PDF has 64 pages
Algorithm for astronomical, point source, signal to noise ratio calculations
An algorithm was developed to simulate the expected signal to noise ratios as a function of observation time in the charge coupled device detector plane of an optical telescope located outside the Earth's atmosphere for a signal star, and an optional secondary star, embedded in a uniform cosmic background. By choosing the appropriate input values, the expected point source signal to noise ratio can be computed for the Hubble Space Telescope using the Wide Field/Planetary Camera science instrument
Willingness-To-Pay for Food of the Own Region: Empirical Estimates from Hypothetical and Incentive Compatible Settings
The ongoing liberalisation of the European food market provides incentives to producers to seek for innovative strategies of product differentiation. One possibility to differentiate the own product from competing ones is its region-of-origin. In this paper, we investigate consumers' willingness-to-pay and underlying preferences for food of the own region. We consider fresh milk as an example. Underlying data stem from a hypothetical contingent valuation and from an incentive compatible experimental setting with real payoffs. We find that consumers perceive fresh milk from local farmers as a trustful, high quality product, and that consumers are interested in supporting local producers. Given that price premiums are small, both methods suggest a substantial demand for local products. However, compared to contingent-valuation estimates, the inclusion of real payoffs leads to a significant decrease in the willingness-to-pay stated. This decrease can mainly be assigned to "pretending altruists": free riding subjects who respond according to social norms as long as no costs are involved.Consumer/Household Economics,
A survey of stellar X-ray flares from the XMM-Newton serendipitous source catalogue: Hipparcos-Tycho cool stars
The X-ray emission from flares on cool (i.e. spectral-type F-M) stars is
indicative of very energetic, transient phenomena, associated with energy
release via magnetic reconnection. We present a uniform, large-scale survey of
X-ray flare emission. The XMM-Newton Serendipitous Source Catalogue and its
associated data products provide an excellent basis for a comprehensive and
sensitive survey of stellar flares - both from targeted active stars and from
those observed serendipitously in the half-degree diameter field-of-view of
each observation. The 2XMM Catalogue and the associated time-series
(`light-curve') data products have been used as the basis for a survey of X-ray
flares from cool stars in the Hipparcos Tycho-2 catalogue. In addition, we have
generated and analysed spectrally-resolved (i.e. hardness-ratio), X-ray
light-curves. Where available, we have compared XMM OM UV/optical data with the
X-ray light-curves. Our sample contains ~130 flares with well-observed
profiles; they originate from ~70 stars. The flares range in duration from ~1e3
to ~1e4 s, have peak X-ray fluxes from ~1e-13 to ~1e-11 erg/cm2/s, peak X-ray
luminosities from ~1e29 to ~1e32 erg/s, and X-ray energy output from ~1e32 to
~1e35 erg. Most of the ~30 serendipitously-observed stars have little
previously reported information. The hardness-ratio plots clearly illustrate
the spectral (and hence inferred temperature) variations characteristic of many
flares, and provide an easily accessible overview of the data. We present flare
frequency distributions from both target and serendipitous observations. The
latter provide an unbiased (with respect to stellar activity) study of flare
energetics; in addition, they allow us to predict numbers of stellar flares
that may be detected in future X-ray wide-field surveys. The serendipitous
sample demonstrates the need for care when calculating flaring rates.Comment: 26 pages, 24 figures. Additional tables and figures available as 4
ancillary files. To be published in Astronomy and Astrophysic
A statistical mechanics model for free-for-all airplane passenger boarding
I present and discuss a model for the free-for-all passenger boarding which
is employed by some discount air carriers. The model is based on the principles
of statistical mechanics where each seat in the aircraft has an associated
energy which reflects the preferences of the population of air travelers. As
each passenger enters the airplane they select their seats using Boltzmann
statistics, proceed to that location, load their luggage, sit down, and the
partition function seen by remaining passengers is modified to reflect this
fact. I discuss the various model parameters and make qualitative comparisons
of this passenger boarding model with models which involve assigned seats. This
model can also be used to predict the probability that certain seats will be
occupied at different times during the boarding process. These results may be
of value to industry professionals as a useful description of this boarding
method. However, it also has significant value as a pedagogical tool since it
is a relatively unusual application of undergraduate level physics and it
describes a situation with which many students and faculty may be familiar.Comment: version 1: 4 pages 2 figures version 2: 7 pages with 5 figure
Biochemistry and Waste Treatment
Paper by E. D. Schroeder, a graduate student in Environmental Science and Engineering at Rice Universit
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