1,212 research outputs found
Knowledge Rich Natural Language Queries over Structured Biological Databases
Increasingly, keyword, natural language and NoSQL queries are being used for
information retrieval from traditional as well as non-traditional databases
such as web, document, image, GIS, legal, and health databases. While their
popularity are undeniable for obvious reasons, their engineering is far from
simple. In most part, semantics and intent preserving mapping of a well
understood natural language query expressed over a structured database schema
to a structured query language is still a difficult task, and research to tame
the complexity is intense. In this paper, we propose a multi-level
knowledge-based middleware to facilitate such mappings that separate the
conceptual level from the physical level. We augment these multi-level
abstractions with a concept reasoner and a query strategy engine to dynamically
link arbitrary natural language querying to well defined structured queries. We
demonstrate the feasibility of our approach by presenting a Datalog based
prototype system, called BioSmart, that can compute responses to arbitrary
natural language queries over arbitrary databases once a syntactic
classification of the natural language query is made
Symbolic Dynamics Analysis of the Lorenz Equations
Recent progress of symbolic dynamics of one- and especially two-dimensional
maps has enabled us to construct symbolic dynamics for systems of ordinary
differential equations (ODEs). Numerical study under the guidance of symbolic
dynamics is capable to yield global results on chaotic and periodic regimes in
systems of dissipative ODEs which cannot be obtained neither by purely
analytical means nor by numerical work alone. By constructing symbolic dynamics
of 1D and 2D maps from the Poincare sections all unstable periodic orbits up to
a given length at a fixed parameter set may be located and all stable periodic
orbits up to a given length may be found in a wide parameter range. This
knowledge, in turn, tells much about the nature of the chaotic limits. Applied
to the Lorenz equations, this approach has led to a nomenclature, i.e.,
absolute periods and symbolic names, of stable and unstable periodic orbits for
an autonomous system. Symmetry breakings and restorations as well as
coexistence of different regimes are also analyzed by using symbolic dynamics.Comment: 35 pages, LaTeX, 13 Postscript figures, uses psfig.tex. The revision
concerns a bug at the end of hlzfig12.ps which prevented the printing of the
whole .ps file from page 2
Neutrino Spin Transitions and the Violation of the Equivalence Principle
The violation of the equivalence principle (VEP) causing neutrino
oscillations is of current interest. We study here the possibility of not only
flavor oscillation but spin flavor oscillation of ultra high energy ( 1
PeV) neutrinos emanating from AGN due to VEP and due to the presence of a large
magnetic field ( 1 Tesla) in AGN. In particular we look at the resonance
spin flavor conversion driven by the AGN potential. Interesting bounds on the
transition magnetic moment of neutrinos may therefore be obtained.Comment: Latex, 12 pages, no figures. To appear in Journal of Physics G:
Nuclear and Particle Physics. Two references adde
The Energy of a Trapped Interacting Bose Gas
A Bose gas in an external potential is studied by means of the semi-classical
approximation. Analytical results are derived for the energy of an interacting
Bose gas in a generic power-law trapping potential. An expression for the
chemical potential below the critical temperature is also obtained. The
theoretical results are in qualitative agreement with a recent energy
measurement.Comment: 6 pages, REVTex, one figure
Survey and scientific evaluation of medicinal plants used by the Pahan and Teli tribal communities of Natore district, Bangladesh
The Pahans and the Telis are two of the smallest indigenous communities in Bangladesh. The Pahans, numbering about 14,000 people are widely scattered in several northern districts of the country, while the Telis are such a small community that nothing has been reported on their numbers and lifestyle. Both tribes are on the verge of disappearance. One each of the Pahan and the Teli community was located after much search in two adjoining villages of Natore district, Bangladesh. Since the tribes were found to still depend on their traditional medicinal practitioners for treatment of ailments, it was the objective of the present study to document their traditional usage of medicinal plants and to evaluate such plants against modern research-based pharmacological activity studies on these plants. Interviews were conducted of the practitioners of the Pahan and Teli community of Natore district with the help of a semi-structured questionnaire and using the guided field-walk method. Plant specimens aspointed out by the practitioners were collected and pressed on the field and identification completed at the Bangladesh National Herbarium. The Pahan tribal practitioners used 13 plants distributed into 9 families for treatment of 14 different ailments. The Teli tribal practitioner used 15 plants divided into 14 families for treatment of 17 different ailments. Eight out of the thirteen plants used by the Pahan tribal practitioner (61.5%) had reported relevant pharmacological activities in the scientific literature, while six out of the fifteen plants used by the Teli tribal practitioners (40%) had such relevant pharmacological activities in accordance with their usage. The medicinal plants used by the Pahans and Telis warrant further scientific studies toward discovery of lead compounds and efficacious drugs and the documentation and protection of the traditional medical knowledge held by these tribes
Patterned Geometries and Hydrodynamics at the Vortex Bose Glass Transition
Patterned irradiation of cuprate superconductors with columnar defects allows
a new generation of experiments which can probe the properties of vortex
liquids by confining them to controlled geometries. Here we show that an
analysis of such experiments that combines an inhomogeneous Bose glass scaling
theory with the hydrodynamic description of viscous flow of vortex liquids can
be used to infer the critical behavior near the Bose glass transition. The
shear viscosity is predicted to diverge as at the Bose glass
transition, with the dynamical critical exponent.Comment: 5 pages, 4 figure
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