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Análise de distúrbios relacionados com a qualidade da energia elétrica utilizando a transformada Wavelet; Analysis of power quality disturbances using Wavelet transform

Arruda, Elcio Franklin de
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 07/04/2003 PT
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O presente trabalho visa a utilização da transformada Wavelet no monitoramento do sistema elétrico no que diz respeito a problemas de qualidade da energia com o intuito de detectar, localizar e classificar os mesmos. A transformada Wavelet tem surgido na literatura como uma nova ferramenta para análise de sinais, utilizando funções chamadas Wavelet mãe para mapear sinais em seu domínio, fornecendo informações simultâneas nos domínios tempo e freqüência. A transformada Wavelet é realizada através de filtros decompondo-se um dado sinal em análise multiresolução. Por esta, obtém-se a detecção e a localização de distúrbios relacionados com a qualidade da energia decompondo-se o sinal em dois outros que representam uma versão de detalhes (correspondente as altas freqüências do sinal) e uma versão de aproximação (correspondente as baixas freqüências do sinal). A versão de aproximação é novamente decomposta obtendo-se novos sinais de detalhes e aproximações e assim sucessivamente. Sendo assim, os distúrbios podem ser detectados e localizados no tempo em função do seu conteúdo de freqüência. Estas informações fornecem também características únicas pertinentes a cada distúrbio, permitindo classificá-los. Desta forma...

O algebroide classificante de uma estrutura geometrica; The classifying Lie algebroid of a geometric structure

Ivan Struchiner
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 23/01/2009 PT
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O objetivo desta tese é mostrar como utilizar algebróides de Lie e grupóides de Lie para compreender aspectos das teorias de invariantes, simetrias e espaços de moduli de estruturas geométricas de tipo finito. De uma forma geral, podemos descrever tais estruturas como sendo objetos, definidos em uma variedade, que podem ser caracterizados por correferenciais (possivelmente em outra variedade). Exemplos incluem G-estruturas de tipo finito e geometrias de Cartan. Para uma classe de estruturas geométricas de tipo finito cujo espaço de moduli (dos germes) de seus elementos tem dimensão finita, construímos um algebróide de Lie A X, chamado de algebróide de Lie classificante, que satisfaz as seguintes propriedades: 1. Para cada ponto na base X corresponde um germe de uma estrutura geométrica pertencente à classe. 2. Dois destes germes são isomorfos se e somente se eles correspondem ao mesmo ponto de X. 3. A álgebra de Lie de isotropia de A num ponto x é a álgebra de Lie das simetrias infinitesimais da estrutura geométrica correspondente. 4. Se dois germes de estruturas geométricas pertencem à mesma estrutura geométrica global numa variedade conexa, então eles correspondem a pontos na mesma órbita de A em X. Além do mais...

A Neural Architecture for Potentially Classifying Cytology Specimens by Machines*

Harvey, R.L.; DiCaprio, P.N.; Heinemann, K.G.; Silverman, M.L.; Dugan, J.M.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em 07/11/1990 EN
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This paper describes a general purpose vision system. We have applied the system to classifying cytology specimens. The system uses neural network and conventional processing modules to model biological vision systems. The modules make up a locating channel and a classifying channel. The locating channel finds individual cells in the field-of-view. The classifying channel learns and recognizes the cells. Learning is by example. We tested the classifying channel on 156 cell images from human cervical smears. Results suggest one can drive the false negative and false positive rates below a few percent for initial screening. Training would require several hundred cells of normal and abnormal types.

Automatically classifying sentences in full-text biomedical articles into Introduction, Methods, Results and Discussion

Agarwal, Shashank; Yu, Hong
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Artigo de Revista Científica
EN
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Biomedical texts can be typically represented by four rhetorical categories: Introduction, Methods, Results and Discussion (IMRAD). Classifying sentences into these categories can benefit many other text-mining tasks. Although many studies have applied different approaches for automatically classifying sentences in MEDLINE abstracts into the IMRAD categories, few have explored the classification of sentences that appear in full-text biomedical articles. We first evaluated whether sentences in full-text biomedical articles could be reliably annotated into the IMRAD format and then explored different approaches for automatically classifying these sentences into the IMRAD categories. Our results show an overall annotation agreement of 82.14% with a Kappa score of 0.756. The best classification system is a multinomial naïve Bayes classifier trained on manually annotated data that achieved 91.95% accuracy and an average F-score of 91.55%, which is significantly higher than baseline systems. A web version of this system is available online at—http://wood.ims.uwm.edu/full_text_classifier/.

O sistema de classificação nominal Akwe-Xerente (Jê): âmbitos de análise; The system of classification Akwe-Xerente:scope of analysis

SIQUEIRA, Kênia Mara de Freitas
Fonte: Universidade Federal de Goiás; BR; UFG; Doutorado em Letras e Linguistica; Linguistica, Letras e Artes Publicador: Universidade Federal de Goiás; BR; UFG; Doutorado em Letras e Linguistica; Linguistica, Letras e Artes
Tipo: Tese de Doutorado Formato: application/pdf
POR
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The need to describe and document the languages threatened with extinction has been gaining importance in the last decades, given the growing risks of cultural loss and the knowledge accumulated by indigenous people. The purpose of continuity of each one of these languages is ensured by actions based on the results of studies which focus on the description of the sociolinguistic problem, as well as on the description and analysis of the linguistic aspects which characterize the language of a determined linguistic family, since the death of a language means, among many other things, an undetermined loss of the science of Linguistics and, above all, the disrespect for the rights of these people to preserve their immaterial richness. The present research has as objective to answer some questions regarding the use of classifiers, terms of classes and names in classifying function as components of the classifying system of the language Akwe-Xerente (Jê), spoken by the indigenous people of the same name. The Akwe-Xerente add up to about 3,100 people and inhabit indigenous lands in the region of Tocantinia, in the Tocantins State. The description of the system of the Xerente classification is based on theoretical functional references for the recognition and differentiation of some nominal radicals which may occur in the function of classifying or organizing the classes which show common characteristics amongst the designated items such as form...

A taxonomical structure for classifying the goods purchased by the Federal Government

Wenger, Brian L.
Fonte: Monterey, California. Naval Postgraduate School Publicador: Monterey, California. Naval Postgraduate School
Tipo: Tese de Doutorado
EN_US
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Approved for public release, distribution unlimited; This thesis is an attempt to develop a taxonomical structure to use in the classification of the goods purchased by the Federal Government. The primary objective was to develop a usable scheme that practitioners could employ in classifying goods along a continuum from simple to complex. A secondary objective of this thesis was to determine the characteristics of the goods, other than their obvious physical differences, to utilize in classifying. Using 21 randomly selected heterogeneous goods and a scaling process, a survey was conducted to determine the relationship between these goods and the chosen characteristics. Cluster analysis was then utilized to group the goods into categories that exhibited similar characteristics. As a result of the research, a taxonomical structure for classifying the population of Government goods into five categories was developed. The potential benefits from using such a scheme could arise in the staffing and directing of procurement functions, training and education of the acquisition workforce, and refinement of procurement policy. It is recommended that the taxonomical model resulting from this research be validated and refined through further use.

A taxonomical structure for classifying the services procured by the Federal Government

Allen, Scott Thomas
Fonte: Monterey, California: U.S. Naval Postgraduate School Publicador: Monterey, California: U.S. Naval Postgraduate School
Tipo: Tese de Doutorado
EN_US
Relevância na Pesquisa
26.76%
This thesis was an attempt to develop a taxonomical scheme that practitioners may employ in classifying services that are procured by the Federal Government along a continuum from procurements that are strategically complex. A secondary research objective was to determine what characteristics are appropriate for classifying services on a strategic basis. A literature review, expert interviews, and survey using 20 heterogeneous sample services were conducted to determine the relationship between characteristics and services. Cluster analysis was used to group services into categories with similar compositions of selected characteristics. A taxonomical structure was developed for classifying services into five categories. Potential benefits may arise via application to staffing and directing of procurement functions and refinement of procurement policy. Is is recommended that the taxonomical model resulting from this research be validated and refined through further use.

Classifying aging as a disease in the context of ICD-11

Zhavoronkov, Alex; Bhullar, Bhupinder
Fonte: Frontiers Media S.A. Publicador: Frontiers Media S.A.
Tipo: Artigo de Revista Científica
Publicado em 04/11/2015 EN
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Aging is a complex continuous multifactorial process leading to loss of function and crystalizing into the many age-related diseases. Here, we explore the arguments for classifying aging as a disease in the context of the upcoming World Health Organization’s 11th International Statistical Classification of Diseases and Related Health Problems (ICD-11), expected to be finalized in 2018. We hypothesize that classifying aging as a disease with a “non-garbage” set of codes will result in new approaches and business models for addressing aging as a treatable condition, which will lead to both economic and healthcare benefits for all stakeholders. Actionable classification of aging as a disease may lead to more efficient allocation of resources by enabling funding bodies and other stakeholders to use quality-adjusted life years (QALYs) and healthy-years equivalent (HYE) as metrics when evaluating both research and clinical programs. We propose forming a Task Force to interface the WHO in order to develop a multidisciplinary framework for classifying aging as a disease with multiple disease codes facilitating for therapeutic interventions and preventative strategies.

Espacios clasificantes de categorías fibradas; Classifying spaces of fibred categories

del Hoyo, Matías L.
Fonte: Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires Publicador: Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires
Tipo: info:eu-repo/semantics/doctoralThesis; tesis doctoral; info:eu-repo/semantics/publishedVersion Formato: application/pdf
Publicado em //2009 SPA
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Esta tesis se desarrolla en torno al estudio de los espacios clasificantes de fibraciones de categorías. Toda categoría pequeña tiene asociado de un modo natural un espacio topológico, su espacio clasificante. Introducimos variantes de esta construcción para el caso en que la categoría tiene estructura fibrada. A partir de estas nuevas construcciones obtenemos nuevos resultados en la teoría de homotopía de categorías, e interpretamos desde un nuevo punto de vista y de un modo conceptual varios de los teoremas clásicos de Quillen, Segal y Thomason. Entre los resultados obtenidos destacamos una versión relativa del Teorema A de Quillen, una versión homológica de ese mismo Teorema y una sucesión espectral, análoga a la clásica sucesión espectral de Serre, para calcular la homología de fibraciones de Grothendieck. Exponemos también una construcción novedosa para la subdivisión de una categoría, y derivaciones de esta construcción en teoría de homotopía de posets y en teoría de categorías. Por último, estudiamos la generalización de espacios clasificantes a 2-categorías, e implementamos los resultados expuestos en homotopía de categorías fibradas para caracterizar los espacios de lazos de las 2-categorías. Parte de los resultados obtenidos fueron publicados en los artículos [dH08a] y [dH08b]...

The Borel-Serre Compactification for the Classifying Space of Hodge Structures

Scherk, John
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
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A 1-parameter variation of Hodge structures corresponds to a holomorphic, horizontal, locally liftable map into a classifying space of Hodge structures. In this paper it is shown that such a map has a limit in the reductive Borel-Serre compactification of the classifying space. The boundary component in which the limit lies is a union over possible polarizations of classifying spaces of Hodge structures on the primitive parts. It is discussed which boundary components can contain such limit points.; Comment: This paper has been withdrawn by the author. Errors in article

The classifying topos of a topological bicategory

Bakovic, Igor; Jurco, Branislav
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
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26.85%
For any topological bicategory B, the Duskin nerve NB of B is a simplicial space. We introduce the classifying topos BB of B as the Deligne topos of sheaves Sh(NB) on the simplicial space NB. It is shown that the category of geometric morphisms Hom(Sh(X),BB) from the topos of sheaves Sh(X) on a topological space X to the Deligne classifying topos is naturally equivalent to the category of principal B-bundles. As a simple consequence, the geometric realization |NB| of the nerve NB of a locally contractible topological bicategory B is the classifying space of principal B-bundles, giving a variant of the result of Baas, Bokstedt and Kro derived in the context of bicategorical K-theory. We also define classifying topoi of a topological bicategory B using sheaves on other types of nerves of a bicategory given by Lack and Paoli, Simpson and Tamsamani by means of bisimplicial spaces, and we examine their properties.; Comment: accepted for a publication in "Homology, Homotopy and Applications"

Alternative stable homotopy classification of p-completed classifying spaces

Ragnarsson, Kari
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
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We give an alternative to the stable classification of p-completed homotopy types of classifying spaces of finite groups offered by Martino-Priddy. For a finite group G with Sylow subgroup S, we regard the stable p-completed classifying space of G as an object under the stable p-completed classifying space of S via the canonical inclusion map. Thus we get a classification in terms of induced fusion systems. Applying Oliver's solution to the Martino-Priddy conjecture, we obtain the surprising result that the unstable p-completed homotopy type of BG is determined by the stable p-completed inclusion of BS in BG, but not by the stable p-completed homotopy type of BG.; Comment: 10 pages. Clarified text after Definition 1.1 and altered discussion in Section 4 following suggestions from referee. To appear in Topology

A Segal conjecture for p-completed classifying spaces

Ragnarsson, Kari
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
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We formulate and prove a new variant of the Segal Conjecture describing the group of homotopy classes of stable maps from the p-completed classifying space of a finite group G to the classifying space of a compact Lie group K as the p-adic completion of the Grothendieck group of finite principal (G,K)-bundles whose isotropy groups are p-groups. Collecting the result for different primes p, we get a new and simple description of the group of homotopy classes of stable maps between (uncompleted) classifying spaces of groups. This description allows us to determine the kernel of the map from the Grothendieck group A(G,K) of finite principal (G,K)-bundles to the group of homotopy classes of stable maps from BG to BK.; Comment: 31 pages. Minor changes. Final version, to appear in Advances in Mathematics

Classifying spaces for homogeneous manifolds and their related Lie isometry deformations

Rainer, M.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 28/02/1996
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Among plenty of applications, low-dimensional homogeneous spaces appear in cosmological models as both, classical factor spaces of multidimensional geometry and minisuperspaces in canonical quantization. Here a new tool to restrict their continuous deformations is presented: Classifying spaces for homogeneous manifolds and their related Lie isometry deformations. The adjoint representation of n-dimensional real Lie algebras induces a natural topology on their classifying space, which encodes the natural algebraic relationship between different Lie algebras therein. For n>1 this topology is not Hausdorffian. Even more it satisfies only the separation axiom T_0, but not T_1, i.e. there is a constant sequence which has a limit different from the members of the sequence. Such a limit is called a transition. Recently it was found that transitions are the natural generalization and transitive completion of the well-known In\"on\"u-Wigner contractions. For n<5 the relational classifying spaces are constructed explicitly. Calculating their characteristic scalar invariants via triad representations of the characteristic isometry, local homogeneous Riemannian 3-spaces are classified in their natural geometrical relations to each other. Their classifying space is a composition of pieces with different isometry types. Although it is Hausdorffian...

De Morgan classifying toposes

Caramello, Olivia
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 11/08/2008
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26.76%
We present a general method for deciding whether a Grothendieck topos satisfies De Morgan's law (resp. the law of excluded middle) or not; applications to the theory of classifying toposes follow. Specifically, we obtain a syntactic characterization of the class of geometric theories whose classifying toposes satisfy De Morgan's law (resp. are Boolean), as well as model-theoretic criteria for theories whose classifying toposes arise as localizations of a given presheaf topos.; Comment: 37 pages

Classifying spectra of saturated fusion systems

Ragnarsson, Kari
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
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The assignment of classifying spectra to saturated fusion systems was suggested by Linckelmann and Webb and has been carried out by Broto, Levi and Oliver. A more rigid (but equivalent) construction of the classifying spectra is given in this paper. It is shown that the assignment is functorial for fusion-preserving homomorphisms in a way which extends the assignment of stable p-completed classifying spaces to finite groups, and admits a transfer theory analogous to that for finite groups. Furthermore the group of homotopy classes of maps between classifying spectra is described, and in particular it is shown that a fusion system can be reconstructed from its classifying spectrum regarded as an object under the stable classifying space of the underlying p-group.; Comment: This is the version published by Algebraic & Geometric Topology on 26 February 2006

Classifying spaces for braided monoidal categories and lax diagrams of bicategories

Carrasco, P.; Cegarra, A. M.; Garzón, A. R.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
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This work contributes to clarifying several relationships between certain higher categorical structures and the homotopy type of their classifying spaces. Bicategories (in particular monoidal categories) have well understood simple geometric realizations, and we here deal with homotopy types represented by lax diagrams of bicategories, that is, lax functors to the tricategory of bicategories. In this paper, it is proven that, when a certain bicategorical Grothendieck construction is performed on a lax diagram of bicategories, then the classifying space of the resulting bicategory can be thought of as the homotopy colimit of the classifying spaces of the bicategories that arise from the initial input data given by the lax diagram. This result is applied to produce bicategories whose classifying space has a double loop space with the same homotopy type, up to group completion, as the underlying category of any given (non-necessarily strict) braided monoidal category. Specifically, it is proven that these double delooping spaces, for categories enriched with a braided monoidal structure, can be explicitly realized by means of certain genuine simplicial sets characteristically associated to any braided monoidal categories, which we refer to as their (Street's) geometric nerves.; Comment: This a revised version (with 59 pages now) of our paper on realizations of braided categories...

Classifying Topoi and Preservation of Higher Order Logic by Geometric Morphisms

Henry, Shawn J.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 14/05/2013
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26.85%
Topoi are categories which have enough structure to interpret higher order logic. They admit two notions of morphism: logical morphisms which preserve all of the structure and therefore the interpretation of higher order logic, and geometric morphisms which only preserve only some of the structure and therefore only some of the interpretation of higher order logic. The question then arises: what kinds of higher order theories are preserved by geometric morphisms? It is known that certain first order theories called internal geometric theories are preserved by geometric morphisms, and these admit what are known as classifying topoi. Briefly, a classifying topos for an internal geometric theory $\mathbb{T}$ in a topos $\mathcal{E}$ is a topos $\mathcal{E}[\mathbb{T}]$ such that models of $\mathbb{T}$ in any topos $\mathcal{F}$ with a geometric morphism to $\mathcal{E}$ are in one to one correspondence with geometric morphisms from $\mathcal{F}$ to $\mathcal{E}[\mathbb{T}]$ over $\mathcal{E}$. One useful technique for showing that a higher order theory $\mathcal{T}$ is preserved by geometric morphisms is to define an internal geometric theory $\mathbb{T}$ of "bad sets" for $\mathcal{T}$ and show that $\mathcal{T}$ is equivalent to the higher order theory which says "the classifying topos for $\mathbb{T}$ is degenerate". We set up a deduction calculus for internal geometric theories and show that it proves a contradiction if and only if the classifying topos of that theory is degenerate. We use this result to study a variant of the higher order theory of Dedekind finite objects and the higher order theory of field objects considered as ring objects with no non-trivial ideals.

Recognizing nullhomotopic maps into the classifying space of a Kac-Moody group

Foley, John D.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
26.91%
This paper extends certain characterizations of nullhomotopic maps between p-compact groups to maps with target the p-completed classifying space of a connected Kac-Moody group and source the classifying space of either a p-compact group or a connected Kac-Moody group. A well known inductive principle for p-compact groups is applied to obtain general, mapping space level results. An arithmetic fiber square computation shows that a null map from the classifying space of a connected compact Lie group to the classifying space of a connected topological Kac-Moody group can be detected by restricting to the maximal torus. Null maps between the classifying spaces of connected topological Kac-Moody groups cannot, in general, be detected by restricting to the maximal torus due to the nonvanishing of an explicit abelian group of obstructions described here. Nevertheless, partial results are obtained via the application of algebraic discrete Morse theory to higher derived limit calculations which show that such detection is possible in many cases of interest.; Comment: References added, minor corrections; 29 pages, 4 figures, one table

Intermediaries in Bredon (co)homology and classifying spaces

Dembegioti, F.; Petrosyan, N.; Talelli, O.
Fonte: Universidade Autônoma de Barcelona Publicador: Universidade Autônoma de Barcelona
Tipo: Artigo de Revista Científica Formato: application/pdf
Publicado em //2012 ENG
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36.63%
For certain contractible G-CW-complexes and F a family of subgroups of G, we construct a spectral sequence converging to the F-Bredon cohomology of G with E1-terms given by the F-Bredon cohomology of the stabilizer subgroups. As applications, we obtain several corollaries concerning the cohomological and geometric dimensions of the classifying space EFG. We also introduce, for any subgroup closed class of groups F, a hierarchically de ned class of groups and show that if a group G is in this class, then G has finite F ∩ G-Bredon (co)homological dimension if and only if G has jump F ∩ G-Bredon (co)homology.