94 resultados para hierarchical classification system

em Repositório Institucional UNESP - Universidade Estadual Paulista "Julio de Mesquita Filho"


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Malware has become a major threat in the last years due to the ease of spread through the Internet. Malware detection has become difficult with the use of compression, polymorphic methods and techniques to detect and disable security software. Those and other obfuscation techniques pose a problem for detection and classification schemes that analyze malware behavior. In this paper we propose a distributed architecture to improve malware collection using different honeypot technologies to increase the variety of malware collected. We also present a daemon tool developed to grab malware distributed through spam and a pre-classification technique that uses antivirus technology to separate malware in generic classes. © 2009 SPIE.

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Land cover mappings represent important tools for the regional planning. However, the current mappings are related to very specific purposes and, consequently, they are limited in their capacity to define the wide variety of existing types of land cover. In that context, this paper aims at developing a wide and including hierarchical classification system for land cover mapping in regional scale, which should contribute for a future standardization of classes. Besides, it is intended to test that system for a study case that contemplates the use of a classification method based on fuzzy approach, which has shown to be more appropriate than conventional approaches. Therefore, it was proposed a hierarchical classification system with three detailing levels and a study case was defined with the specification of the test area and of the classification project. Then, the georreferencing of a TM/Landsat-5 image that comprises the test area was carried out. Later, it was applied a fuzzy classification approach in the TM/Landsat-5 image, starting from images of probability for the mapped classes and an uncertainty image were generated. Finally, it was produced a conventional output that represents the thematic mapping of the test area.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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This paper proposes a fuzzy classification system for the risk of infestation by weeds in agricultural zones considering the variability of weeds. The inputs of the system are features of the infestation extracted from estimated maps by kriging for the weed seed production and weed coverage, and from the competitiveness, inferred from narrow and broad-leaved weeds. Furthermore, a Bayesian network classifier is used to extract rules from data which are compared to the fuzzy rule set obtained on the base of specialist knowledge. Results for the risk inference in a maize crop field are presented and evaluated by the estimated yield loss. © 2009 IEEE.

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In this paper we presente a classification system that uses a combination of texture features from stromal regions: Haralick features and Local Binary Patterns (LBP) in wavelet domain. The system has five steps for classification of the tissues. First, the stromal regions were detected and extracted using segmentation techniques based on thresholding and RGB colour space. Second, the Wavelet decomposition was applied in the extracted regions to obtain the Wavelet coefficients. Third, the Haralick and LBP features were extracted from the coefficients. Fourth, relevant features were selected using the ANOVA statistical method. The classication (fifth step) was performed with Radial Basis Function (RBF) networks. The system was tested in 105 prostate images, which were divided into three groups of 35 images: normal, hyperplastic and cancerous. The system performance was evaluated using the area under the ROC curve and resulted in 0.98 for normal versus cancer, 0.95 for hyperplasia versus cancer and 0.96 for normal versus hyperplasia. Our results suggest that texture features can be used as discriminators for stromal tissues prostate images. Furthermore, the system was effective to classify prostate images, specially the hyperplastic class which is the most difficult type in diagnosis and prognosis.

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Schistosomiasis is still an endemic disease in many regions, with 250 million people infected with Schistosoma and about 500,000 deaths per year. Praziquantel (PZQ) is the drug of choice for schistosomiasis treatment, however it is classified as Class II in the Biopharmaceutics Classification System, as its low solubility hinders its performance in biological systems. The use of cyclodextrins is a useful tool to increase the solubility and bioavailability of drugs. The aim of this work was to prepare an inclusion compound of PZQ and methyl-beta-cyclodextrin (MeCD), perform its physico-chemical characterization, and explore its in vitro cytotoxicity. SEM showed a change of the morphological characteristics of PZQ:MeCD crystals, and IR data supported this finding, with changes after interaction with MeCD including effects on the C-H of the aromatic ring, observed at 758 cm(-1). Differential scanning calorimetry measurements revealed that complexation occurred in a 1:1 molar ratio, as evidenced by the lack of a PZQ transition temperature after inclusion into the MeCD cavity. In solution, the PZQ UV spectrum profile in the presence of MeCD was comparable to the PZQ spectrum in a hydrophobic solvent. Phase solubility diagrams showed that there was a 5.5-fold increase in PZQ solubility, and were indicative of a type A(L) isotherm, that was used to determine an association constant (K(a)) of 140.8 M(-1). No cytotoxicity of the PZQ:MeCD inclusion compound was observed in tests using 3T3 cells. The results suggest that the association of PZQ with MeCD could be a good alternative for the treatment of schistosomiasis.

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O presente trabalho objetivou verificar a possibilidade da utilização de métodos estatísticos multivariados na caracterização das fases do desenvolvimento do mosaico sucessional de um trecho de floresta estacional semidecidual, através de variáveis estruturais. Foram alocadas parcelas de 10 m x 10 m, em que se procedeu à análise estrutural, ou seja, levantamento fitossociológico acrescido das variáveis Porcentagem de Cobertura (PC), Altura do Dossel (AD) e Cobertura por Lianas (CL). Os métodos estatísticos empregados foram Análise de Componentes Principais e Análise de Agrupamento, mais especificamente Classificação Hierárquica Ascendente. O primeiro componente principal explicou 43,96% da variância total, enquanto o segundo, 25,66%. As variáveis Área Basal (AB), Diâmetro Médio (DM) e Dominância Média (DOM) apresentaram correlações positivas entre si superiores a 0,75, podendo ser DM e DOM consideradas como um grupo de variáveis. As variáveis Número de Indivíduos (NI) e Número de Espécies (NE) apresentaram correlação 0,60, enquanto AD, CL e PC baixas correlações com as demais, indicando a importância da inclusão destas na análise. A classificação hierárquica e a partição dos grupos em quatro foram feitas considerando os dois primeiros eixos fatoriais. Os resultados indicaram dois comportamentos diferenciados: 1) valores baixos para AD e AB: Grupo 1, com valores baixos também para NI, NE e PC (fase de clareira); e Grupo 2, com valores elevados para NI e CL e baixos para DOM e DM (fase de construção); e 2) valores altos para AD e AB: Grupo 3, com valores altos também para NI, NE e PC e valor baixo para CL (fase madura); e Grupo 4, com valores elevados para DOM e DM e mais baixos para CL (fase de degradação). Os métodos estatísticos multivariados permitiram caracterizar as fases do desenvolvimento do mosaico sucessional, através das variáveis estruturais. A forma como foram estimadas as variáveis AD, CL e PC, porém, deve ser aprimorada, assim como é preciso incluir variáveis que discriminem melhor cada fase.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Este artigo deriva de uma pesquisa mais ampla sobre a educação em astronomia e a formação de professores, e apresenta um panorama geral sobre o tema em âmbito nacional. Procuramos gerar uma classificação das instituições e outras iniciativas brasileiras dedicadas à astronomia, levando em conta os seus objetivos, tais como o ensino formal, informal, não-formal, bem como aqueles destinados à popularização dessa ciência. Comenta-se, em forma de um breve ensaio, a importância da atuação contextualizada destas instâncias no ensino da astronomia, levantando um desafio ainda a ser considerado, referente ao estudo das possíveis relações entre estes estabelecimentos e iniciativas, visando o avanço da educação em astronomia, em um movimento contrário à dispersão e pulverização de atividades locais e pontuais dos mesmos. Argumentamos que a pesquisa em ensino de astronomia tem potencial para exercer este papel integrador.

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This study contributes to a critical synthesis of the principle of literary warrant, initially formulated by Hulme in 1911. Hulme proposed that the terms of a classification system should be derived from the literature to be classified, rather than based on purely theoretical considerations. Founding literary warrant on literature which is actually documented rather than on scientific or philosophical classifications or on the supposed authority of the first classificationists implied a clear departure from the conceptions of Harris and Dewey, who had used the classifications of Bacon and Leibniz as models. The validity of this principle over the past century is studied by means of diverse documental data (entries in dictionaries, retrieval by Google, etc.), as it is recognized as a main methodological element for classification standards and systems. This study also discusses the situation with respect to the top-down or bottom-up methodologies of system design. Three traditional applications of literary warrant are described as well as three new applications are suggested, in light of its methodological potential. It is possible to conclude that this principle will find increasing applications in other contexts, within and beyond Information Science.

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Background: Cerebral palsy (CP) presents changes in posture and movement as a core characteristic, which requires therapeutic monitoring during the habilitation or rehabilitation of children. Besides clinical treatment, it is fundamental that professionals use systems of evaluation to quantify the difficulties presented to the individual and assist in the organization of a therapeutic program. The aim of this study was to quantitatively verify the performance of children with spastic di-paresia type CP.Methods: The Pediatric Evaluation of Disability Inventory (PEDI) and Gross Motor Function Classification System (GMFM) tests were used and classification made through the GMFCS in the assessment of 7 patients with CP, 4 females and 3 males, average age of 9 years old.Results: According to GMFCS scales, 17% (n=1) were level II and 83% (n=6) were level III. The PEDI test and 88 GMFM items were used in the area of mobility. We observed that there was high correlation between mobility and gross motor function with Pearson's correlation coefficient =0.929) showing the likely impact of these areas in the functional skills and the quality of life of these patients.Conclusion: We suggest the impact of the limitation of the areas in functional skills and quality of life of these patients.

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This work presents a bibliometric profile of Bioethics Journal according to the following journal databases: MEDLINE, LILACS, The Philosopher' s Index, Ulrich's, SciELO and Qualis classification system (Brazil). We found that: from 38 titles indexed in MEDLINE, 25 (66%) still exist; the country with the highest number is the U. S. A (36%); most Bioethics journals appeared in the 1990's (47%), and 36% have less than 10 years of existence. From those that disappeared (34%), the average survival time was about 4 years. There are only 12 countries with indexed journals. In Brazil, from 3 Bioethics journals, only one is (partially) indexed. English is the preponderant language (45%). Only 3% of journals are monthly. LILACS has two additional publications (Acta Bioethica, Chile, and Revista Latino Americana, Colombia). SciELO has only Acta Bioethica. In Ulrich's database, there are eight additional publications. In "Qualis" classification system there are four journals.

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OBJETIVO: A catarata é a principal causa tratável de cegueira e deficiência visual em países subdesenvolvidos. Este estudo foi realizado para avaliar se a catarata continua sendo uma importante causa de cegueira no centro-oeste do Estado de São Paulo. MÉTODOS: Um estudo transversal, de caráter observacional, realizado em cinco cidades da região centro-oeste do Estado de São Paulo, para as quais o centro de referência é a cidade de Botucatu. A amostra estabelecida para este estudo, de forma aleatória, seria composta por 5.555 indivíduos, sendo que foram examinados 4.229 indivíduos (8.458 olhos), ou seja, 78% da amostra pretendida. Os indivíduos foram submetidos a um exame oftalmológico completo que consistia em avaliação da acuidade visual (com e sem correção), tonometria, biomicroscopia, fundoscopia e exame refracional. O diagnóstico de catarata foi dado aos indivíduos que apresentassem opacidade de cristalino na biomicroscopia, de acordo com o Sistema de Classificação de Opacidade do Cristalino II (LOCS II). Olhos apresentando deficiência visual ou cegueira, com a melhor correção e causados por catarata, foram considerados após excluir outras patologias que pudessem causar baixa da acuidade visual (AV). Olhos com deficiência visual foram considerados quando 0,05 < AV < 0,3 e olhos cegos quando AV < 0,05. Indivíduos com deficiência visual foram considerados quando 0,05 < AV < 0,3 e indivíduos cegos quando AV < 0,3, no melhor olho com a melhor correção. Foi considerado o número de olhos com catarata, o número de olhos com deficiência visual e cegueira e o número de indivíduos com deficiência visual e cegueira. RESULTADOS: A prevalência de catarata na população estudada foi de 4,94% (209 indivíduos), afetando principalmente indivíduos com mais de 50 anos (92,34%) e do sexo feminino (61,11%). A catarata foi a causa de deficiência visual para 0,96% e a causa de cegueira para 0,52% de toda a população estudada. CONCLUSÃO: Nossos resultados mostraram que a prevalência de catarata na população estudada é semelhante aos índices de países desenvolvidos.

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O objetivo do estudo foi comparar os resultados de investigações de acidentes aeronáuticos brasileiros do Centro de Investigação e Prevenção de Acidentes Aeronáuticos (Cenipa) com os do sistema de análise e classificação de fatores humanos (Human Factors Analysis and Classification System - HFACS). Foram analisados e comparados os relatórios finais de 36 investigações de acidentes aeronáuticos ocorridos entre 2000 e 2005, no estado de São Paulo. Foram mencionados 163 fatores contribuintes dos acidentes aeronáuticos nos relatórios do Cenipa, enquanto 370 foram identificados por meio do HFACS. Conclui-se que as análises do Cenipa não contemplaram fatores organizacionais associados aos acidentes aéreos.