128,162 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
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
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
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)
AceWiki: Collaborative Ontology Management in Controlled Natural Language
AceWiki is a prototype that shows how a semantic wiki using controlled
natural language - Attempto Controlled English (ACE) in our case - can make
ontology management easy for everybody. Sentences in ACE can automatically be
translated into first-order logic, OWL, or SWRL. AceWiki integrates the OWL
reasoner Pellet and ensures that the ontology is always consistent. Previous
results have shown that people with no background in logic are able to add
formal knowledge to AceWiki without being instructed or trained in advance
Local Multicoloring Algorithms: Computing a Nearly-Optimal TDMA Schedule in Constant Time
The described multicoloring problem has direct applications in the context of
wireless ad hoc and sensor networks. In order to coordinate the access to the
shared wireless medium, the nodes of such a network need to employ some medium
access control (MAC) protocol. Typical MAC protocols control the access to the
shared channel by time (TDMA), frequency (FDMA), or code division multiple
access (CDMA) schemes. Many channel access schemes assign a fixed set of time
slots, frequencies, or (orthogonal) codes to the nodes of a network such that
nodes that interfere with each other receive disjoint sets of time slots,
frequencies, or code sets. Finding a valid assignment of time slots,
frequencies, or codes hence directly corresponds to computing a multicoloring
of a graph . The scarcity of bandwidth, energy, and computing resources in
ad hoc and sensor networks, as well as the often highly dynamic nature of these
networks require that the multicoloring can be computed based on as little and
as local information as possible
AceWiki: A Natural and Expressive Semantic Wiki
We present AceWiki, a prototype of a new kind of semantic wiki using the
controlled natural language Attempto Controlled English (ACE) for representing
its content. ACE is a subset of English with a restricted grammar and a formal
semantics. The use of ACE has two important advantages over existing semantic
wikis. First, we can improve the usability and achieve a shallow learning
curve. Second, ACE is more expressive than the formal languages of existing
semantic wikis. Our evaluation shows that people who are not familiar with the
formal foundations of the Semantic Web are able to deal with AceWiki after a
very short learning phase and without the help of an expert.Comment: To be published as: Proceedings of Semantic Web User Interaction at
CHI 2008: Exploring HCI Challenges, CEUR Workshop Proceeding
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