122,336 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
Public perceptions of unreliability in examination results in England: a new perspective
Presented at the 36th International Association for Educational Assessment (IAEA) Annual Conference in Bangkok, Thailand, 22-27 August 2010. This report is about a quantitative study on public perceptions of unreliability in examination results, using an online questionnaire survey
Double marking revisited
In 2002, the Qualifications and Curriculum Authority (QCA) published the report of an independent panel of experts into maintaining standards at Advanced Level (A-Level). One of its recommendations was for: ‘limited experimental double marking of scripts in subjects such as English to determine whether the strategy would signi-ficantly reduce errors of measurement’ (p. 24). This recommendation provided the impetus for this paper which reviews the all but forgotten literature on double marking and considers its relevance now
A Local Deterministic Model of Quantum Spin Measurement
The conventional view, that Einstein was wrong to believe that quantum
physics is local and deterministic, is challenged. A parametrised model, Q, for
the state vector evolution of spin 1/2 particles during measurement is
developed. Q draws on recent work on so-called riddled basins in dynamical
systems theory, and is local, deterministic, nonlinear and time asymmetric.
Moreover the evolution of the state vector to one of two chaotic attractors
(taken to represent observed spin states) is effectively uncomputable.
Motivation for this model arises from Penrose's speculations about the nature
and role of quantum gravity. Although the evolution of Q's state vector is
uncomputable, the probability that the system will evolve to one of the two
attractors is computable. These probabilities correspond quantitatively to the
statistics of spin 1/2 particles. In an ensemble sense the evolution of the
state vector towards an attractor can be described by a diffusive random walk.
Bell's theorem and a version of the Bell-Kochen_specker quantum entanglement
paradox are discussed. It is shown that proving an inconsistency with locality
demands the existence of definite truth values to certain counterfactual
propositions. In Q these deterministic propositions are physically uncomputable
and no non-algorithmic solution is either known or suspected. Adapting the
mathematical formalist approach, the non-existence of definite truth values to
such counterfactual propositions is posited. No inconsistency with experiment
is found. Hence Q is not necessarily constrained by Bell's inequality.Comment: This paper has been accepted for publication in the Proceedings of
the Royal Society of London (Proc.Roy.Soc.A) I will mail the paper's figures
on request (write to [email protected]
High angular resolution near-infrared integral field observations of young star cluster complexes in NGC1365
This paper presents and examines new near-infrared integral field
observations of the three so-called 'embedded star clusters' located in the
nuclear region of NGC1365. Adaptive-optics- corrected K-band data cubes were
obtained with the ESO/VLT instrument SINFONI. The continuum in the K-band and
emission lines such as HeI, Bracket-gamma, and several H2 lines were mapped at
an achieved angular resolution of 0.2arcsec over a field of 3x3arcsec^2 around
each source. We find that the continuum emission of the sources is spatially
resolved. This means that they are indeed cluster complexes confined to regions
of about 50pc extension. We performed robust measurements of the equivalent
width of the CO absorption band at 2.3micro and of Bracket-gamma. For the main
mid-infrared bright sources, the data only allow us to determine an upper limit
to the equivalent width of the CO bands. Under the assumption of an
instantaneously formed standard initial mass function Starburst99 model, the
new measurements are found to be incompatible with previously published
mid-infrared line ratios. We show that an upper mass limit of 25 to 30 solar
masses, lower than the typically assumed 100solar masses, allows one to simply
remove this inconsistency. For such a model, the measurements are consistent
with ages in the range of 5.5Myr to 6.5Myr, implying masses in the range from 3
to 10 x 10^6 solar masses. We detect extended gas emission both in HII and H2.
We argue that the central cluster complexes are the sources of excitation for
the whole nebulae, through ionisation and shock heating. We detect a blue wing
on the Bracket-gamma emission profile, suggesting the existence of gas outflows
centred on the cluster complexes. We do not find any evidence for the presence
of a lower mass cluster population, which would fill up a 'traditional' power
law cluster mass function.Comment: 15 pages, 10 figures, accepted for publication in A&
The Neutral Hydrogen Column Density towards Q1937--1009 from the Unabsorbed Intrinsic Continuum in the Lyman- Forest
The absorption system at towards Q1937--1009 provides the best
extragalactic measurement of the atomic deuterium to hydrogen ratio, D/H. We
have obtained a new low-resolution, high signal-to-noise ratio (SNR) Keck
spectrum to re-measure the total neutral hydrogen column density N(H I) using
the amount of Lyman continuum absorption. We develop a new method to directly
determine the intrinsic unabsorbed quasar continuum from low-resolution spectra
of the \Lya forest for the first time. We use three types of spectra to measure
N(H I): (1) A wide slit spectrum for flux calibration, (2) a high-resolution
spectrum to determine the unabsorbed continuum between \Lya forest lines, and
(3) a high SNR spectrum to measure the residual flux below the Lyman limit. We
measure Log [N(H I)] = 17.86 0.02 \cm2, which is reliable because N(H I)
is fully specified by the data. This result is consistent with the N(H I)
measured by Tytler, Fan & Burles (1996) from the Lyman series absorption lines,
but not with absorption models proposed by Wampler (1996) nor estimates of the
total N(H I) by Songaila et al. (1997), both of which suggested lower N(H I)
and higher D/H. The Wampler models predict abundant flux below the Lyman limit
which is absent from both our old and new spectra, taken with different
instruments. The new Keck data is consistent with the data presented by
Songaila et al. (1997). The results differ due to the different methods of
analysis, and our measurement of the QSO continuum does not agree with the
continuum models assumed by Songaila et al. (1997).Comment: 15 pages, 6 figures, To appear in the Astronomical Journal in October
199
Measurement of SUSY masses via cascade decays for SPS 1a
If R-parity conserving supersymmetry exists below the TeV-scale, new particles will be produced and decay in cascades at the LHC. The lightest supersymmetric particle will escape the detectors, thereby complicating the full reconstruction of the decay chains. In this paper we expand on existing methods for determining the masses of the particles in the cascade from endpoints of kinematical distributions. We perform scans in the mSUGRA parameter space to delimit the region where this method is applicable. From the examination of theoretical distributions for a wide selection of mass scenarios it is found that caution must be exerted when equating the theoretical endpoints with the experimentally obtainable ones. We provide analytic formulae for the masses in terms of the endpoints most readily available. Complications due to the composite nature of the endpoint expressions are discussed in relation to the detailed analysis of two points on the SPS 1a line. Finally we demonstrate how a Linear Collider measurement can improve dramatically on the precision of the masses obtained
Development and Validation of the Behavioral Tendencies Questionnaire
At a fundamental level, taxonomy of behavior and behavioral tendencies can be described
in terms of approach, avoid, or equivocate (i.e., neither approach nor avoid). While there are
numerous theories of personality, temperament, and character, few seem to take advantage
of parsimonious taxonomy. The present study sought to implement this taxonomy by
creating a questionnaire based on a categorization of behavioral temperaments/tendencies
first identified in Buddhist accounts over fifteen hundred years ago. Items were developed
using historical and contemporary texts of the behavioral temperaments, described as
“Greedy/Faithful”, “Aversive/Discerning”, and “Deluded/Speculative”. To both maintain
this categorical typology and benefit from the advantageous properties of forced-choice
response format (e.g., reduction of response biases), binary pairwise preferences for items
were modeled using Latent Class Analysis (LCA). One sample (n1 = 394) was used to estimate
the item parameters, and the second sample (n2 = 504) was used to classify the participants
using the established parameters and cross-validate the classification against
multiple other measures. The cross-validated measure exhibited good nomothetic span
(construct-consistent relationships with related measures) that seemed to corroborate the
ideas present in the original Buddhist source documents. The final 13-block questionnaire
created from the best performing items (the Behavioral Tendencies Questionnaire or BTQ)
is a psychometrically valid questionnaire that is historically consistent, based in behavioral
tendencies, and promises practical and clinical utility particularly in settings that teach and
study meditation practices such as Mindfulness Based Stress Reduction (MBSR)
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