3,345 research outputs found
TaXEm: a tool for aiding the evaluation of domain topic.
The notorious advances in textual information storage need fast and effcient tools to organize, retrieve and browse this information and tools for knowledge extraction. A very interesting way to organize specific domain information is the topic taxonomy building. Moreover a great challenge in this research area is the result evaluation and validation. This evaluation can be carried out through objective measures or through a subjective analysis, which is based on the domain specialist judgment. The measures CQM and SQM [1] are used to evaluate a generated taxonomy against a reference taxonomy. A reference taxonomy is constructed by human and consolidated through its community use along the years. The CQM is used to evaluate the generated taxonomy relatively to the selected descriptors for each taxonomy node; on the other hand, the SQM is used to evaluate the taxonomy structure. As these objective measures do not encompass the specialist knowledge, the specialist evaluation is very important. However the human evaluation is expensive, because this task involves readiness, time and dedication from the specialists. In this way, the TaXEm tool claims to reduce the subjective evaluation costs. The TaXEm (Taxonomia em XML da Embrapa) tool offers subsidies for carrying out a taxonomy (semi)automatic evaluation, which allows the user to implement some automatic evaluation before going on a subjective evaluation.Propor 2010. Demonstration
Modeling quasi-dark states with Temporal Coupled-Mode Theory
Coupled resonators are commonly used to achieve tailored spectral responses
and allow novel functionalities in a broad range of applications, from optical
modulation and filtering in integrated photonic circuits to the study of
nonlinear dynamics in arrays of resonators. The Temporal Coupled-Mode Theory
(TCMT) provides a simple and general tool that is widely used to model these
devices and has proved to yield very good results in many different systems of
low-loss, weakly coupled resonators. Relying on TCMT to model coupled
resonators might however be misleading in some circumstances due to the
lumped-element nature of the model. In this article, we report an important
limitation of TCMT related to the prediction of dark states. Studying a coupled
system composed of three microring resonators, we demonstrate that TCMT
predicts the existence of a dark state that is in disagreement with
experimental observations and with the more general results obtained with the
Transfer Matrix Method (TMM) and the Finite-Difference Time-Domain (FDTD)
simulations. We identify the limitation in the TCMT model to be related to the
mechanism of excitation/decay of the supermodes and we propose a correction
that effectively reconciles the model with expected results. A comparison with
TMM and FDTD allows to verify both steady-state and transient solutions of the
modified-TCMT model. The proposed correction is derived from general
considerations, energy conservation and the non-resonant power circulating in
the system, therefore it provides good insight on how the TCMT model should be
modified to eventually account for the same limitation in a different
coupled-resonator design. Moreover, our discussion based on coupled microring
resonators can be useful for other electromagnetic resonant systems due to the
generality and far-reach of the TCMT formalism.Comment: 7 pages, 4 figure
PERCEPÇÕES E PRÁTICAS DE MÃES DE PRÉ-ESCOLARES BRASILEIROS ACERCA DA ALIMENTAÇÃO DOS FILHOS
Introduction: In March, 2006, there were 5,.588,.153 children aged 4 to 6 years enrolled in Brazilian pre-schools. Unfortunately only 3.8% of these institutions have a health professional, in addition to which, the relationship between the pre-schools and the Health System is poor. The first 5 years of life are crucial in the development of good eating habits, and consequently, for preventing degenerative illnesses in later life, such as obesity. Objective: The aim of this study is to identify and analyze maternal perceptions and practices concerning the eating behaviors of children aged 3 to 6 years attending a Brazilian pre-school. Material and methods: A qualitative survey was carried out using individual, non-directive interviews. 21 mothers were interviewed: 10 with children enrolled in full-time classes and 11 with children in part-time classes. In terms of height and weight, the children were between the 10 and 90 percentile (NCHS standard). For data analysis we used the method of Thematic Content Analysis, as proposed by Bardin. Results: Diet is an issue of major concern for these mothers. The main difficulty is child development: they do not know how to deal with it. Therefore, they use harmful strategies, such as bargaining, coercion, disguising food, and punishment. Also, they do not know how food is served in the pre-school. However, 15 of the 21 children improved their eating behavior after attending the institution (autonomy, regular meal times, and better meal choices), particularly twhose attending the pre-school on a full-time basis. Conclusion: Brazilian pre-schools ought to implement health programs in partnership with the SUS (Unified Health System) - the Brazilian national health system.En marzo de 2006, existían 5.588.153 de niños entre 4 y 6 años de edad matriculados en escuelas de preescolar en Brasil. Lamentablemente, sólo el 3.8% de esas instituciones tiene un profesional de salud y, además, no existe una relación efectiva entre esas instituciones y el Sistema de Salud en el país. Los primeros cinco años de vida son cruciales en el desarrollo de hábitos alimentares sanos y, consecuentemente, en la prevención de enfermedades degenerativas en la fase adulta, y también de la obesidad. Objetivo: Identificar y analizar las percepciones y prácticas maternas sobre la alimentación de niños de 3 a 6 años que frecuentaban una preescuela brasileña. Material y Método: Estudio cualitativo con entrevistas a fondo, individuales y no directivas, involucrando a madres de preescolares, donde los criterios para inclusión fueron: edad del niño entre 3 y 6 años; mínimo de 1 año de preescuela y peso del niños entre los percentiles 10 y 90 (gráficos NCHS). 21 madres fueron entrevistadas: 10 cuyos hijos estaban matriculados en el período integral y 11 en el período parcial. Para el análisis de los datos, fueron utilizados los métodos del Análisis Temático de Contenido, propuesto por Bardin. Resultados: La alimentación es tema de gran preocupación para las madres. La principal dificultad se refiere a los cambios propios del desarrollo infantil: No saben lidiar con esos cambios y, así, usan varias estrategias perjudiciales, tales como cambalache, insistencia, castigo y coerción, además de camuflar o mezclar los alimentos recusados con los aceptados. Las madres en este estudio tampoco sabían cómo eran los momentos de alimentación en la preescuela, aunque 15 de los 21 niños mejoraron la conducta alimentaria después de frecuentar la institución (autonomía, mejora en elhábito alimentario y estandarización en los horarios de las comidas), especialmente los niños de período integral. Conclusión: Las preescuelas brasileñas deberían implementar programas de salud en colaboración con el Sistema Único de Salud.Introdução: Em Março de 2006, existiam 5.588.153 crianças de 4 a 6 anos matriculadas em pré-escolas no Brasil. Infelizmente, apenas 3.8% dessas instituições têm um profissional da saúde e, adicionalmente, não existe relação efetiva entre essas instituições e o Sistema de Saúde no país. Os primeiros cinco anos de vida são cruciais no desenvolvimento de hábitos alimentares saudáveis e, consequentemente, na prevenção de doenças degenerativas na fase adulta, assim como a obesidade. Objetivo: identificar e analisar as percepções e práticas maternas sobre a alimentação de crianças de 3 a 6 anos que frequentavam uma pré-escola brasileira. Material e Método: estudo qualitativo com entrevistas aprofundadas, individuais e não-diretivas, realizado com mães de pré-escolares, onde os critérios para inclusão foram: idade da criança entre 3 e 6 anos; tempo de frequência à pré-escola de, no mínimo 1 ano e peso da criança entre os percentis 10 e 90 (gráficos NCHS). Vinte e uma mães foram entrevistadas: 10 cujos filhos estavam matriculados no período integral e 11 no período parcial. Para a análise dos dados, foram utilizados os métodos da Análise Temática de Conteúdo, proposta por Bardin. Resultados: a alimentação é assunto que causa preocupação e dificuldades para as mães, devido as mudanças peculiares ao desenvolvimento infantil. Devido a isto usam diversas estratégias negativas para tentar modificar o comportamento alimentar dos filhos, sendo elas: barganha, insistência, castigo e coação, além de misturar ou camuflar os alimentos recusados com os aceitos. Além disto, as mães não tinham informações sobre a alimentação na pré-escola. No entanto, 15 das 21 crianças melhoraram o comportamento alimentar depois de começarem a frequentar a instituição. Ficaram mais autônomas, passaram a aceitar novos alimentos e padronizaram os horários das refeições. As mudanças foram mais evidentes nas crianças que frequentam a pré-escola período integral (de 8 a 9.5 horas por dia). Conclusão: as mães não sabem lidar, no domicílio, com as peculiaridades de desenvolvimento dos filhos na área de alimentação. Além disto, desconhecem seus comportamentos alimentares na pré-escola, onde há melhoras em comparação com o domicílio. Sugere-se melhorar a comunicação entre famílias e pré-escola, além de parceria entre estas e o sistema público de saúde
Generative Temporal Models with Spatial Memory for Partially Observed Environments
In model-based reinforcement learning, generative and temporal models of
environments can be leveraged to boost agent performance, either by tuning the
agent's representations during training or via use as part of an explicit
planning mechanism. However, their application in practice has been limited to
simplistic environments, due to the difficulty of training such models in
larger, potentially partially-observed and 3D environments. In this work we
introduce a novel action-conditioned generative model of such challenging
environments. The model features a non-parametric spatial memory system in
which we store learned, disentangled representations of the environment.
Low-dimensional spatial updates are computed using a state-space model that
makes use of knowledge on the prior dynamics of the moving agent, and
high-dimensional visual observations are modelled with a Variational
Auto-Encoder. The result is a scalable architecture capable of performing
coherent predictions over hundreds of time steps across a range of partially
observed 2D and 3D environments.Comment: ICML 201
Facilitando a avaliação de taxonomias de tópicos automaticamente geradas no domínio do agronegócio.
O custo de avaliação de taxonomias automaticamente geradas costuma ser alto se realizado exclusivamente por especialistas do domínio. Neste trabalho propõe-se uma forma de validação objetiva para o vocabulário automaticamente obtido, com o qual uma taxonomia automaticamente gerada é representada. Para isso, o vocabulário gerado é comparado ao de uma taxonomia pré-existente, já validada, bem aceita e que use um thesaurus ou dicionário específico do domínio. Como taxonomias validadas foram utilizadas algumas árvores da Agência de Informação Embrapa e como vocabulário padrão o contido no Thesagro.SBIAgro 2009
Easily labelling hierarchical document clusters.
One of the problems of automatic models that generate topic taxonomies is the process of creating the most significant term list that discriminates each document group. In this paper, a new method to label document hierarchical clusters is proposed, which is completely independent from the clustering method. This method automatically decides the number of the words in each label list, avoids word repetitions in a tree branch and provides a kind of cutting for the cluster tree. The obtained results were tested as search queries in a retrieval process and showed a very good performance. Additionally, the use of the method was experimented by some specialists in the text collection domain, trying to evaluate their understanding and expectations over the results
Spectral Engineering with Coupled Microcavities: Active Control of Resonant Mode-Splitting
Optical mode-splitting is an efficient tool to shape and fine-tune the
spectral response of resonant nanophotonic devices. The active control of
mode-splitting, however, is either small or accompanied by undesired resonance
shifts, often much larger than the resonance-splitting. We report a control
mechanism that enables reconfigurable and widely tunable mode-splitting while
efficiently mitigating undesired resonance shifts. This is achieved by actively
controlling the excitation of counter-traveling modes in coupled resonators.
The transition from a large splitting (80 GHz) to a single-notch resonance is
demonstrated using low power microheaters (35 mW). We show that the spurious
resonance-shift in our device is only limited by thermal crosstalk and
resonance-shift-free splitting control may be achieved.Comment: 4 pages, 3 figure
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