99,013 research outputs found
Product and other fine structure in polynomial resolutions of mapping spaces
Let Map_T(K,X) denote the mapping space of continuous based functions between
two based spaces K and X. If K is a fixed finite complex, Greg Arone has
recently given an explicit model for the Goodwillie tower of the functor
sending a space X to the suspension spectrum \Sigma^\infty Map_T(K,X). Applying
a generalized homology theory h_* to this tower yields a spectral sequence, and
this will converge strongly to h_*(Map_T(K,X)) under suitable conditions, e.g.
if h_* is connective and X is at least dim K connected. Even when the
convergence is more problematic, it appears the spectral sequence can still
shed considerable light on h_*(Map_T(K,X)). Similar comments hold when a
cohomology theory is applied. In this paper we study how various important
natural constructions on mapping spaces induce extra structure on the towers.
This leads to useful interesting additional structure in the associated
spectral sequences. For example, the diagonal on Map_T(K,X) induces a
`diagonal' on the associated tower. After applying any cohomology theory with
products h^*, the resulting spectral sequence is then a spectral sequence of
differential graded algebras. The product on the E_\infty -term corresponds to
the cup product in h^*(Map_T(K,X)) in the usual way, and the product on the
E_1-term is described in terms of group theoretic transfers. We use explicit
equivariant S-duality maps to show that, when K is the sphere S^n, our
constructions at the fiber level have descriptions in terms of the
Boardman-Vogt little n-cubes spaces. We are then able to identify, in a
computationally useful way, the Goodwillie tower of the functor from spectra to
spectra sending a spectrum X to \Sigma ^\infty \Omega ^\infty X.Comment: Published by Algebraic and Geometric Topology at
http://www.maths.warwick.ac.uk/agt/AGTVol2/agt-2-28.abs.htm
Micellization in the presence of polyelectrolyte
We present a simple model to study micellization of amphiphiles condensed on
a rodlike polyion. Although the mean field theory leads to a first order
micellization transition for sufficiently strong hydrophobic interactions, the
simulations show that no such thermodynamic phase transition exists. Instead,
the correlations between the condensed amphiphiles can result in a structure
formation very similar to micelles.Comment: 8 pages, 7 figure
How to Evaluate Controlled Natural Languages
This paper presents a general framework how controlled natural languages can
be evaluated and compared on the basis of user experiments. The subjects are
asked to classify given statements (in the language to be tested) as either
true or false with respect to a certain situation that is shown in a graphical
notation called "ontographs". A first experiment has been conducted that
applies this framework to the language Attempto Controlled English (ACE)
Combining Semantic Wikis and Controlled Natural Language
We demonstrate AceWiki that is a semantic wiki using the controlled natural
language Attempto Controlled English (ACE). The goal is to enable easy creation
and modification of ontologies through the web. Texts in ACE can automatically
be translated into first-order logic and other languages, for example OWL.
Previous evaluation showed that ordinary people are able to use AceWiki without
being instructed
Codeco: A Grammar Notation for Controlled Natural Language in Predictive Editors
Existing grammar frameworks do not work out particularly well for controlled
natural languages (CNL), especially if they are to be used in predictive
editors. I introduce in this paper a new grammar notation, called Codeco, which
is designed specifically for CNLs and predictive editors. Two different parsers
have been implemented and a large subset of Attempto Controlled English (ACE)
has been represented in Codeco. The results show that Codeco is practical,
adequate and efficient
Futility Analysis in the Cross-Validation of Machine Learning Models
Many machine learning models have important structural tuning parameters that
cannot be directly estimated from the data. The common tactic for setting these
parameters is to use resampling methods, such as cross--validation or the
bootstrap, to evaluate a candidate set of values and choose the best based on
some pre--defined criterion. Unfortunately, this process can be time consuming.
However, the model tuning process can be streamlined by adaptively resampling
candidate values so that settings that are clearly sub-optimal can be
discarded. The notion of futility analysis is introduced in this context. An
example is shown that illustrates how adaptive resampling can be used to reduce
training time. Simulation studies are used to understand how the potential
speed--up is affected by parallel processing techniques.Comment: 22 pages, 5 figure
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