2,501,578 research outputs found
The expressive power of modal logic with inclusion atoms
Modal inclusion logic is the extension of basic modal logic with inclusion
atoms, and its semantics is defined on Kripke models with teams. A team of a
Kripke model is just a subset of its domain. In this paper we give a complete
characterisation for the expressive power of modal inclusion logic: a class of
Kripke models with teams is definable in modal inclusion logic if and only if
it is closed under k-bisimulation for some integer k, it is closed under
unions, and it has the empty team property. We also prove that the same
expressive power can be obtained by adding a single unary nonemptiness operator
to modal logic. Furthermore, we establish an exponential lower bound for the
size of the translation from modal inclusion logic to modal logic with the
nonemptiness operator.Comment: In Proceedings GandALF 2015, arXiv:1509.0685
OH emission from cometary knots in planetary nebulae
We model the molecular emission from cometary knots in planetary nebulae
(PNe) using a combination of photoionization and photodissociation region (PDR)
codes, for a range of central star properties and gas densities. Without the
inclusion of ionizing extreme ultraviolet (EUV) radiation, our models require
central star temperatures to be near the upper limit of the range
investigated in order to match observed H and OH surface brightnesses
consistent with observations - with the addition of EUV flux, our models
reproduce observed OH surface brightnesses for .
For , the predicted OH surface brightness is much
lower, consistent with the non-detection of this molecule in PNe with such
central star temperatures. Our predicted level of H emission is somewhat
weaker than commonly observed in PNe, which may be resolved by the inclusion of
shock heating or fluorescence due to UV photons. Some of our models also
predict ArH and HeH rotational line emission above detection
thresholds, despite neither molecule having been detected in PNe, although the
inclusion of photodissociation by EUV photons, which is neglected by our
models, would be expected to reduce their detectability.Comment: Accepted by MNRAS, 11 pages, 15 figures. Author accepted manuscript.
Accepted on 24/04/18. Deposited on 27/04/1
Susy Particles
Analysis of the SUSY spectrum in supergravity unified models is given under
the naturalness criterion that the universal scalar mass and the gluino
mass satisfy the constraint less than or
equal to 1 TeV. The SUSY spectrum is analysed in four different scenarios: (1)
minimal supergravity models ignoring proton decay from dimension five
operators, (2) imposing proton stability constraint in supergravity models with
SU(5) type embedding which allow proton decay via dimension five operators, (3)
with inclusion of dark matter constraints in models of type (1), and (4) with
inclusion of dark matter constraint in models of type (2). It is found that
there is a very strong upper limit on the light chargino mass in models of type
(4), i.e., the light chargino mass is less than or equals 120 GeV.Comment: 16 pages+ 6 figs(hard copies available on request
POS tagging for German : how important is the right context?
Part-of-Speech tagging is generally performed by Markov models, based on bigram or trigram models. While Markov models have a strong concentration on the left context of a word, many languages require the inclusion of right context for correct disambiguation. We show for German that the best results are reached by a combination of left and right context. If only left context is available, then changing the direction of analysis and going from right to left improves the results. In a version of MBT (Daelemans et al., 1996) with default parameter settings, the inclusion of the right context improved POS tagging accuracy from 94.00% to 96.08%, thus corroborating our hypothesis. The version with optimized parameters reaches 96.73%
Mean-field limit for collective behavior models with sharp sensitivity regions
We rigorously show the mean-field limit for a large class of swarming
individual based models with local sharp sensitivity regions. For instance,
these models include nonlocal repulsive-attractive forces locally averaged over
sharp vision cones and Cucker-Smale interactions with discontinuous
communication weights. We construct global-in-time defined notion of solutions
through a differential inclusion system corresponding to the particle
descriptions. We estimate the error between the solutions to the differential
inclusion system and weak solutions to the expected limiting kinetic equation
by employing tools from optimal transport theory. Quantitative bounds on the
expansion of the 1-Wasserstein distance along flows based on a weak-strong
stability estimate are obtained. We also provide different examples of
realistic sensitivity sets satisfying the assumptions of our main results
Political Interest, Cognitive Ability and Personality - Determinants of Voter Turnout in Britain
This paper uses longitudinal data from the National Cohort Development Study (NCDS) to investigate the determinants of voter turnout in the 1997 British General Election. It introduces measures of cognitive ability and personality into models of electoral participation and finds that firstly, their inclusion reduces the impact of education and secondly, that standard turnout models may be biased by the inclusion of the much used “interest in politics” measure. A bivariate probit model of turnout and interest then shows that individuals with high ability, an aggressive personality and a sense of civic duty are more likely to both turn out to vote and to have an interest in politics.Turnout, Education, Ability, Personality
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