637 research outputs found
Combining Neuro-Fuzzy Classifiers for Improved Generalisation and Reliability
In this paper a combination of neuro-fuzzy
classifiers for improved classification performance and reliability
is considered. A general fuzzy min-max (GFMM) classifier with
agglomerative learning algorithm is used as a main building
block. An alternative approach to combining individual classifier
decisions involving the combination at the classifier model level is
proposed. The resulting classifier complexity and transparency is
comparable with classifiers generated during a single crossvalidation
procedure while the improved classification
performance and reduced variance is comparable to the ensemble
of classifiers with combined (averaged/voted) decisions. We also
illustrate how combining at the model level can be used for
speeding up the training of GFMM classifiers for large data sets
Heegaard Floer homology and integer surgeries on links
Let L be a link in an integral homology three-sphere. We give a description
of the Heegaard Floer homology of integral surgeries on L in terms of some data
associated to L, which we call a complete system of hyperboxes for L. Roughly,
a complete systems of hyperboxes consists of chain complexes for (some versions
of) the link Floer homology of L and all its sublinks, together with several
chain maps between these complexes. Further, we introduce a way of presenting
closed four-manifolds with b_2^+ > 1 by four-colored framed links in the
three-sphere. Given a link presentation of this kind for a four-manifold X, we
then describe the Ozsvath-Szabo mixed invariants of X in terms of a complete
system of hyperboxes for the link. Finally, we explain how a grid diagram
produces a particular complete system of hyperboxes for the corresponding link.Comment: 231 pages, 54 figures; major revision: we now work with one U
variable for each w basepoint, rather than one per link component; we also
added Section 4, with an overview of the main resul
General fuzzy min-max neural network for clustering and classification
This paper describes a general fuzzy min-max (GFMM) neural network which is a generalization and extension of the fuzzy min-max clustering and classification algorithms of Simpson (1992, 1993). The GFMM method combines supervised and unsupervised learning in a single training algorithm. The fusion of clustering and classification resulted in an algorithm that can be used as pure clustering, pure classification, or hybrid clustering classification. It exhibits a property of finding decision boundaries between classes while clustering patterns that cannot be said to belong to any of existing classes. Similarly to the original algorithms, the hyperbox fuzzy sets are used as a representation of clusters and classes. Learning is usually completed in a few passes and consists of placing and adjusting the hyperboxes in the pattern space; this is an expansion-contraction process. The classification results can be crisp or fuzzy. New data can be included without the need for retraining. While retaining all the interesting features of the original algorithms, a number of modifications to their definition have been made in order to accommodate fuzzy input patterns in the form of lower and upper bounds, combine the supervised and unsupervised learning, and improve the effectiveness of operations. A detailed account of the GFMM neural network, its comparison with the Simpson's fuzzy min-max neural networks, a set of examples, and an application to the leakage detection and identification in water distribution systems are given
Learning Hybrid Neuro-Fuzzy Classifier Models From Data: To Combine or Not to Combine?
To combine or not to combine? Though not a question of the same gravity as the Shakespeareâs to be or not
to be, it is examined in this paper in the context of a hybrid neuro-fuzzy pattern classifier design process. A general fuzzy
min-max neural network with its basic learning procedure is used within six different algorithm independent learning
schemes. Various versions of cross-validation, resampling techniques and data editing approaches, leading to a generation
of a single classifier or a multiple classifier system, are scrutinised and compared. The classification performance on
unseen data, commonly used as a criterion for comparing different competing designs, is augmented by further four
criteria attempting to capture various additional characteristics of classifier generation schemes. These include: the ability
to estimate the true classification error rate, the classifier transparency, the computational complexity of the learning
scheme and the potential for adaptation to changing environments and new classes of data. One of the main questions
examined is whether and when to use a single classifier or a combination of a number of component classifiers within a
multiple classifier system
A global optimization approach to solve multi-aircraft routing problems
"This chapter appears in Computational Models, Software Engineering and Advanced Technologies in Air Transportation edited by Dr. Li Weigang and Dr. Alexandre G. de Barros. Chap.12 pp.237-259. Copyright 2009. Posted by permission of the publisher."This paper describes the formulation and solution of a multi-aircraft routing problem which is posed as a global optimization calculation. The paper extends previous work (involving a single aircraft using two dimensions) which established that the algorithm DIRECT is a suitable solution technique. The present work considers a number of ways of dealing with multiple routes using different problem decompositions. A further enhancement is the introduction of altitude to the problems so that full three-dimensional routes can be produced. Illustrative numerical results are presented involving up to three aircraft and including examples which feature routes over real-life terrain data
Constructive spherical codes on layers of flat tori
A new class of spherical codes is constructed by selecting a finite subset of
flat tori from a foliation of the unit sphere S^{2L-1} of R^{2L} and designing
a structured codebook on each torus layer. The resulting spherical code can be
the image of a lattice restricted to a specific hyperbox in R^L in each layer.
Group structure and homogeneity, useful for efficient storage and decoding, are
inherited from the underlying lattice codebook. A systematic method for
constructing such codes are presented and, as an example, the Leech lattice is
used to construct a spherical code in R^{48}. Upper and lower bounds on the
performance, the asymptotic packing density and a method for decoding are
derived.Comment: 9 pages, 5 figures, submitted to IEEE Transactions on Information
Theor
Heegaard Floer homology of surgeries on two-bridge links
We give an time algorithm to compute the generalized Heegaard
Floer complexes 's for a two-bridge
link by using nice diagrams. Using the link surgery
formula of Manolescu-Ozsv\'{a}th, we also show that and their
-invariants of all integer surgeries on two-bridge links are determined by
's. We obtain a polynomial time
algorithm to compute of all the surgeries on two-bridge links,
with coefficients. In addition, we calculate some
examples explicitly:
and the -invariants of all integer surgeries on a family of
hyperbolic two-bridge links including the Whitehead link.Comment: 58 pages, 14 figures. Abstract and introduction revised; Theorem 1.1,
Theorem 5.12 (now 5.13) adapted; Section 5.1 adapted; Section 5.6 and Example
5.16 added; sign errors fixed; typos in statement of Proposition 6.8 (now
6.9) corrected and computations simplified; Definition 2.2 (now 2.3)
corrected. arXiv admin note: text overlap with arXiv:1011.1317 by other
author
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