97,259 research outputs found
Measurable cardinals and good -wellorderings
We study the influence of the existence of large cardinals on the existence
of wellorderings of power sets of infinite cardinals with the property
that the collection of all initial segments of the wellordering is definable by
a -formula with parameter . A short argument shows that the
existence of a measurable cardinal implies that such wellorderings do
not exist at -inaccessible cardinals of cofinality not equal to
and their successors. In contrast, our main result shows that these
wellorderings exist at all other uncountable cardinals in the minimal model
containing a measurable cardinal. In addition, we show that measurability is
the smallest large cardinal property that interferes with the existence of such
wellorderings at uncountable cardinals and we generalize the above result to
the minimal model containing two measurable cardinals.Comment: 14 page
Improving Retrieval Results with discipline-specific Query Expansion
Choosing the right terms to describe an information need is becoming more
difficult as the amount of available information increases.
Search-Term-Recommendation (STR) systems can help to overcome these problems.
This paper evaluates the benefits that may be gained from the use of STRs in
Query Expansion (QE). We create 17 STRs, 16 based on specific disciplines and
one giving general recommendations, and compare the retrieval performance of
these STRs. The main findings are: (1) QE with specific STRs leads to
significantly better results than QE with a general STR, (2) QE with specific
STRs selected by a heuristic mechanism of topic classification leads to better
results than the general STR, however (3) selecting the best matching specific
STR in an automatic way is a major challenge of this process.Comment: 6 pages; to be published in Proceedings of Theory and Practice of
Digital Libraries 2012 (TPDL 2012
The Hurewicz dichotomy for generalized Baire spaces
By classical results of Hurewicz, Kechris and Saint-Raymond, an analytic
subset of a Polish space is covered by a subset of if and
only if it does not contain a closed-in- subset homeomorphic to the Baire
space . We consider the analogous statement (which we call
Hurewicz dichotomy) for subsets of the generalized Baire space
for a given uncountable cardinal with
, and show how to force it to be true in a cardinal
and cofinality preserving extension of the ground model. Moreover, we show that
if the Generalized Continuum Hypothesis (GCH) holds, then there is a cardinal
preserving class-forcing extension in which the Hurewicz dichotomy for
subsets of holds at all uncountable regular
cardinals , while strongly unfoldable and supercompact cardinals are
preserved. On the other hand, in the constructible universe L the dichotomy for
sets fails at all uncountable regular cardinals, and the same
happens in any generic extension obtained by adding a Cohen real to a model of
GCH. We also discuss connections with some regularity properties, like the
-perfect set property, the -Miller measurability, and the
-Sacks measurability.Comment: 33 pages, final versio
Expectation Propagation on the Maximum of Correlated Normal Variables
Many inference problems involving questions of optimality ask for the maximum
or the minimum of a finite set of unknown quantities. This technical report
derives the first two posterior moments of the maximum of two correlated
Gaussian variables and the first two posterior moments of the two generating
variables (corresponding to Gaussian approximations minimizing relative
entropy). It is shown how this can be used to build a heuristic approximation
to the maximum relationship over a finite set of Gaussian variables, allowing
approximate inference by Expectation Propagation on such quantities.Comment: 11 pages, 7 figure
Literary Acoustics
Bringing together sound studies and intermediality theory, this essay revisits the notion of âliterary acousticsâ to inquire into the usefulness of intermediality studies for analyzing the relations between literature and sound. The second part of the essay is dedicated to an illustrative analysis of Ben Marcusâs highly experimental, noisy book The Age of Wire and String
Discursive Killings: Intertextuality, Aestheticization, and Death in Nabokov's Lolita
This essay argues that Nabokov's Lolita is suffused with a rhetoric of death. Humbert Humbert's discursive constructions of Lolita trap her in a semantic web of death that conjures up her literal death in childbed at the age of seventeen. My reading of Lolita traces the fibres of that web in the more sinister implications of Humbert's intertextual references, his persistent gestures of aestheticization and his reflections on the nature of nymphets
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