30,888 research outputs found
Towards Large-scale Inconsistency Measurement
We investigate the problem of inconsistency measurement on large knowledge
bases by considering stream-based inconsistency measurement, i.e., we
investigate inconsistency measures that cannot consider a knowledge base as a
whole but process it within a stream. For that, we present, first, a novel
inconsistency measure that is apt to be applied to the streaming case and,
second, stream-based approximations for the new and some existing inconsistency
measures. We conduct an extensive empirical analysis on the behavior of these
inconsistency measures on large knowledge bases, in terms of runtime, accuracy,
and scalability. We conclude that for two of these measures, the approximation
of the new inconsistency measure and an approximation of the contension
inconsistency measure, large-scale inconsistency measurement is feasible.Comment: International Workshop on Reactive Concepts in Knowledge
Representation (ReactKnow 2014), co-located with the 21st European Conference
on Artificial Intelligence (ECAI 2014). Proceedings of the International
Workshop on Reactive Concepts in Knowledge Representation (ReactKnow 2014),
pages 63-70, technical report, ISSN 1430-3701, Leipzig University, 2014.
http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-15056
Study and Design of a Cesium Bombardment Ion Engine System
Cesium bombardment ion engine system design, modification, and testin
Confocal laser scanning microscopy (CLSM) study of hepatocytes cultured on collagen films and gels
Summary of paper describing the process whereby primary hepatocyte cultures form an integral part of many hybrid artificial liver designs, and the extracellular matrix environment of the cultures is an important factor for optimal expression of hepatocyte-specific phenotype. This study investigates the effect of incorporating 20% chondroitin-6-sulphate (Ch6SO4), a glycosaminoglycan (GAG), into collagen films and gels, and crosslinking the films and the gels with 1,6-diaminohexane (DAH) on the viability of hepatocytes cultured for 48 hours
Optimal eavesdropping on QKD without quantum memory
We consider the security of the BB84, six-state and SARG04 quantum key
distribution protocols when the eavesdropper doesn't have access to a quantum
memory. In this case, Eve's most general strategy is to measure her ancilla
with an appropriate POVM designed to take advantage of the post-measurement
information that will be released during the sifting phase of the protocol.
After an optimization on all the parameters accessible to Eve, our method
provides us with new bounds for the security of six-state and SARG04 against a
memoryless adversary. In particular, for the six-state protocol we show that
the maximum QBER for which a secure key can be extracted is increased from
12.6% (for collective attacks) to 20.4% with the memoryless assumption.Comment: 7 pages, 3 figures. Analysis of six-state and SARG04 QKD protocols
adde
Design and testing of a contra-rotating tidal current turbine
A contra-rotating marine current turbine has a number of attractive features: nearzero reactive torque on the support structure, near-zero swirl in the wake, and high relative inter-rotor rotational speeds. Modified blade element modelling theory has been used to design and predict the characteristics of such a turbine, and a model turbine and test rig have been constructed. Tests in a towing tank demonstrated the feasibility of the concept. Power coefficients were high for such a small model and in excellent agreement with predictions, confirming the accuracy of the computational modelling procedures. High-frequency blade loading data were obtained in the course of the experiments. These show the anticipated dynamic components for a contra-rotating machine. Flow visualization of the wake verified the lack of swirl behind the turbine. A larger machine is presently under construction for sea trials
Collective Spin-Density-Wave Response Perpendicular to the Chains of the Quasi One-Dimensional Conductor (TMTSF)2PF6
Microwave experiments along all three directions of the spin-density-wave
model compound (TMTSF)PF reveal that the pinned mode resonance is
present along the and axes. The collective transport is
considered to be the fingerprint of the condensate. In contrast to common quasi
one-dimensional models, the density wave also slides in the perpendicular
direction. The collective response is absent along the least
conducting direction.Comment: 3 pages, 4 figure
The NASA Astrophysics Data System: Data Holdings
Since its inception in 1993, the ADS Abstract Service has become an
indispensable research tool for astronomers and astrophysicists worldwide. In
those seven years, much effort has been directed toward improving both the
quantity and the quality of references in the database. From the original
database of approximately 160,000 astronomy abstracts, our dataset has grown
almost tenfold to approximately 1.5 million references covering astronomy,
astrophysics, planetary sciences, physics, optics, and engineering. We collect
and standardize data from approximately 200 journals and present the resulting
information in a uniform, coherent manner. With the cooperation of journal
publishers worldwide, we have been able to place scans of full journal articles
on-line back to the first volumes of many astronomical journals, and we are
able to link to current version of articles, abstracts, and datasets for
essentially all of the current astronomy literature. The trend toward
electronic publishing in the field, the use of electronic submission of
abstracts for journal articles and conference proceedings, and the increasingly
prominent use of the World Wide Web to disseminate information have enabled the
ADS to build a database unparalleled in other disciplines.
The ADS can be accessed at http://adswww.harvard.eduComment: 24 pages, 1 figure, 6 tables, 3 appendice
Time dependent diffusion in a disordered medium with partially absorbing walls: A perturbative approach
We present an analytical study of the time dependent diffusion coefficient in
a dilute suspension of spheres with partially absorbing boundary condition.
Following Kirkpatrick (J. Chem. Phys. 76, 4255) we obtain a perturbative
expansion for the time dependent particle density using volume fraction of
spheres as an expansion parameter. The exact single particle -operator for
partially absorbing boundary condition is used to obtain a closed form
time-dependent diffusion coefficient accurate to first order in the
volume fraction . Short and long time limits of are checked against
the known short-time results for partially or fully absorbing boundary
conditions and long-time results for reflecting boundary conditions. For fully
absorbing boundary condition the long time diffusion coefficient is found to be
, to the first order of
perturbation theory. Here is small but non-zero, the diffusion
coefficient in the absence of spheres, and the radius of the spheres. The
validity of this perturbative result is discussed
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