Hyperspectral
Mostrando 1-12 de 47 artigos, teses e dissertações.
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1. Sparse Estimation of the Precision Matrix and Plug-In Principle in Linear Discriminant Analysis for Hyperspectral Image Classification
ABSTRACT In this paper, a new method for supervised classification of hyperspectral images is proposed for the case in which the size of the training sample is small. It consists of replacing in the Mahalanobis distance the maximum likelihood estimator of the precision matrix by a sparse estimator. The method is compared with two other existing versions of L
Trends in Computational and Applied Mathematics. Publicado em: 2022
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2. HYPERSPECTRAL SPECTROSCOPY TO DETECT DIFFERENT RESPONSES OF TWO SOYBEAN (GLYCINE MAX) CULTIVARS TO CHARCOAL ROT (MACROPHOMINA PHASEOLINA) TOXIN
ABSTRACT Previous studies have confirmed the potential of hyperspectral spectroscopy (HS) to detect charcoal rot toxin effect on soybean (Glycine max). However, there is no evidence that it can differentiate among difference responses to that effect. This research tested the potential of HS (900–2400 nm) to differentiate different responses to charcoal rot
Eng. Agríc.. Publicado em: 2021-02
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3. Vibrational Spectroscopy and Chemometrics in Forensic Chemistry: Critical Review, Current Trends and Challenges
The present manuscript makes an extensive review of the scientific approaches developed in the last decade involving infrared and Raman spectroscopy combined with chemometrics for solving several issues in the investigation of the most relevant forensic traces, such as questioned documents and currency, explosives, gunshot residues, illicit drugs and body fl
J. Braz. Chem. Soc.. Publicado em: 24/10/2019
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4. CLASS-BASED AFFINITY PROPAGATION FOR HYPERSPECTRAL IMAGE DIMENSIONALITY REDUCTION AND IMPROVEMENT OF MAXIMUM LIKELIHOOD CLASSIFICATION ACCURACY
Resumo Este artigo investiga um método de classificação alternativo que integra o algoritmo de clusterização propagação de afinidade baseado nas classes (PAC) e o Classificador Máxima Verossimilhança (MAXVER) com a finalidade de superar as limitações do MAXVER na classificação de dados de alta dimensionalidade e, assim, melhorar a sua acurácia.
Bol. Ciênc. Geod.. Publicado em: 18/04/2019
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5. Use of Infrared Spectroscopy and Near Infrared Hyperspectral Images to Evaluate Effects of Different Chemical Agents on PET Bottle Surface
PET - poly (ethylene terephthalate) - bottle surfaces were exposed to chemical agents and evaluated with middle infrared spectroscopy (MIR) and near infrared hyperspectral imaging (HSI-NIR). Images (928-2.524 nm) were acquired at different times from bottle surfaces exposed to alkaline, acidic and ethanolic media. Savitzky-Golay smoothing (2nd order polynomi
Mat. Res.. Publicado em: 09/08/2018
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6. Non-invasive spectral detection of the beneficial effects of Bradyrhizobium spp. and plant growth-promoting rhizobacteria under different levels of nitrogen application on the biomass, nitrogen status, and yield of peanut cultivars
ABSTRACT High-throughput phenotyping using spectral reflectance measurements offers the potential to provide more information for making better-informed management decisions at the crop canopy level in real time. The aim of this study was to investigate the suitability of hyperspectral reflectance measurements of the crop canopy for the assessment of biomass
Bragantia. Publicado em: 15/05/2017
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7. Hyperspectral remote sensing to assess the water status, biomass, and yield of maize cultivars under salinity and water stress
ABSTRACT Spectral remote sensing offers the potential to provide more information for making better-informed management decisions at the crop canopy level in real time. In contrast, the traditional methods for irrigation management are generally time-consuming, and numerous observations are required to characterize them. The aim of this study was to investig
Bragantia. Publicado em: 30/01/2017
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8. Physiological and lifestyle factors contributing to risk and severity of peri-orbital dark circles in the Brazilian population
AbstractBACKGROUND:Peri-orbital dark circles are a cosmetic concern worldwide, and have been attributed to hyperpigmentation from allergy or atopic dermatitis, blood stasis, structural shadowing effects, and a thin epidermis/dermis under the eye. It is of interest to better understand lifestyle and demographic risk factors and the relative impact of melanin,
An. Bras. Dermatol.. Publicado em: 2015-08
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9. Resolução multivariada de curvas com mínimos quadrados alternantes: descrição, funcionamento e aplicações
Multivariate Curve Resolution with Alternating Least Squares (MCR-ALS) is a resolution method that has been efficiently applied in many different fields, such as process analysis, environmental data and, more recently, hyperspectral image analysis. When applied to second order data (or to three-way data) arrays, recovery of the underlying basis vectors in bo
Quím. Nova. Publicado em: 2014
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10. CLASSIFICAÇÃO DE FASES EM IMAGENS HIPERESPECTRAIS DE RAIOS X CARACTERÍSTICOS PELO MÉTODO DE AGRUPAMENTO POR DESLOCAMENTO PARA A MÉDIA / PHASE CLASSIFICATION IN CHARACTERISTIC X-RAYS HYPERSPECTRAL IMAGES BY MEAN SHIFT CLUSTERING METHOD
No presente trabalho será introduzido o algoritmo de Agrupamento por Deslocamento para a Média (ADM) como uma alternativa para executar a classificação de fases em materiais a partir de imagens hiperspectrais de mapas raios X característicos. Ao contrário de outras técnicas estatísticas multivariadas, tal como Análise de Componentes Principais (ACP)
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 23/01/2012
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11. Assessing biophysical variable parameters of bean crop with hyperspectral measurements
Recently high spectral resolution sensors have been developed, which allow new and more advanced applications in agriculture. Motivated by the increasing importance of hyperspectral remote sensing data, the need for research is important to define optimal wavebands to estimate biophysical parameters of crop. The use of narrow band vegetation indices (VI) der
Scientia Agricola. Publicado em: 2012-04
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12. Desenvolvimento de um algoritmo para identificação e correção de spikes em espectroscopia Raman de imagem
Raman imaging spectroscopy is a highly useful analytical tool that provides spatial and spectral information on a sample. However, CCD detectors used in dispersive instruments present the drawback of being sensitive to cosmic rays, giving rise to spikes in Raman spectra. Spikes influence variance structures and must be removed prior to the use of multivariat
Química Nova. Publicado em: 2012