RICARDO AMARAL

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Martin Checa-Artasu

Universidad Autónoma Metropolitana-Iztapalapa

Gustavo Zatelli

University of Helsinki

Juan Ballesteros Sánchez

Universidad Pablo de Olavide

Arturo Sanchez Sanz

Universidad Complutense de Madrid

Andrés Maximiliano Tello

Universidad de Playa Ancha de Ciencias de la Educacion

Adolfo Vasquez Rocca

Universidad Complutense de Madrid

Viacheslav Kuleshov

Stockholm University

Juan Albarrán Diego

Universidad Autónoma de Madrid

Philipp Altmann

Universidad Central del Ecuador (UCE)

Pavel H Valer Bellota

Universidad Nacional de San Antonio Abad del Cusco

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Papers by RICARDO AMARAL

Classification of multispectral images in coral environments using a hybrid of classifier ensembles

Neurocomputing, 2010

The accuracy attained in the mapping of underwater areas is limited by the effect of variations i... more The accuracy attained in the mapping of underwater areas is limited by the effect of variations in the water column, which degrade the signal received by the orbital sensor, creating interclasses confusion that introduce errors into the final result of the classification process. In this article we will describe a hybrid classifier ensembles; the classification is done by progressive refining in three stages. At the end of this process, a combining unit links the various partial classifications generated and achieve the accuracy level desired. At the end, the result obtained by the ensemble is compared to the results achieved by the application of multi-class voting scheme methods based on support vector machine: One-Against-the-Rest and One-Against-One. Classification accuracy showed the viability and the potential of using the proposed ensemble to classify images.

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Holocene coastal tectonics in NE Brazil

Geological Society, London, Special Publications, 1998

SP330 Tectonic and Stratigraphic Evolution of Zagros and Makran during the Mesozoic-Cenozoic. Lye... more

Morphological characteristics of rhodolith and correlations with associated sediment in a sandstone reef: Northeast Brazil

Regional Studies in Marine Science, 2016

The continental shelf of Northeast Brazil is a unique geological region, consisting of shallow-wa... more The continental shelf of Northeast Brazil is a unique geological region, consisting of shallow-water rhodolith beds. However, very little information exists about the complexity of this part of the continental shelf and its biogenic sedimentation. The present study analysed the characteristics of rhodoliths (size, shape and structure) and compares these characteristics with the associated sediments (Grain size, biogenic composition and percentage of CaCO3). The study area was located on a sandstone reef area on the inner continental shelf of Northeast Brazil. Our results show that recently dead rhodoliths are the main component of the pebble fraction with mean diameter near to 2 cm. The focal area is characterised by beds of rhodoliths, featuring individuals of all shapes (discoidal, ellipsoidal and spheroidal), with the ellipsoidal shape being the most abundant. The larger rhodoliths exhibited a near spheroidal shape, and their outer growth forms show high branching density (BIV). The associated sediment was predominantly composed of carbonate from marine fauna and flora, and calcareous algae contributed most to the sand fraction of the sediments. Foraminifera and molluscs were the most abundant biogenic fauna associated with the sediment. The grain size of the sediment was mostly medium and coarse carbonate sand. The results illustrate that there are correlations between the morphology of rhodoliths and the associated sediment. The biogenic composition of the sediment (Rhodophyta and Rizopoda) was correlated with different branching densities of rhodoliths (BII and BIV). The distribution of the sediment grain size also correlated with size, shape (diameter and sphericity) and structure (Branching BIII and BIV) of rhodoliths. Therefore, our results highlight that the correlations between associated sediment and diameter of rhodoliths is a reflection of the abiotic conditions, being principally determined by depth and hydrodynamic energy.

Mapping of coral reefs in the continental shelf of Brazilian Northeast through remote sensing

Revista de Gestão Costeira Integrada, 2016

The Continental Shelf has great importance in the study of coastal evolution, provided this area ... more The Continental Shelf has great importance in the study of coastal evolution, provided this area was affected by fluctuations in sea level during the Quaternary period. In the shallow continental shelf of the Northeastern Rio Grande do Norte, Brazil, submerged important geomorphological features can be found in the distance of 6 km from the coastline. Among these features, highlights the reef complex called Parrachos of Rio do Fogo. This study aims to characterize and analyze geomorphological features and benthic surface features found in this reef complex, from the analysis and interpretation of remote sensing products and in situ data collection. In this work, a digital model of bathymetry was created based on unpublished bathymetric data and compositions from images bands of satellite sensors OLI/Landsat-8, MS/GeoEye and PAN/WordView-1, and then analyzed, interpreted and validated through field work. All obtained data and information were stored in a Geographic Information System (GIS). The following geoenvironmental units were mapped: intertidal reefs, submerged reefs, spurs and grooves, pools, sandy bank, sea grasses, bank of algaes, submerged roads, Barreta Channel and the Rio do Fogo Channel. The use of the proposed methodology provided a detailed analysis of submerged geomorphology in the study area. This study may be used as a guide for future decision-making for environmental management in the region.

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Análise da imagem que turistas e comunidade local têm da Área de Proteção Ambiental dos Recifes de Corais - APARC (RN)

Using small format aerial photographs (SFAP) to map coral reefs in Rio Grande do Norte, Brazil

IEEE International Conference on Robotics and Automation, 2004. Proceedings. ICRA '04. 2004, 2004

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Vulnerabilidade Da Zona Costeira De Pititinga/RN, Brasil

Mercator, 2013

Este trabalho apresenta estudo sobre a Vulnerabilidade Natural e Ambiental da região costeira de ... more Este trabalho apresenta estudo sobre a Vulnerabilidade Natural e Ambiental da região costeira de Pititinga, município de Rio do Fogo/RN. Para análise da vulnerabilidade foram considerados os aspectos do meio físico incluindo geologia, geomorfologia e pedologia, o meio biótico representado pelo tema vegetação e o meio antrópico pelo uso e ocupação do solo. O procedimento metodológico para gerar os mapas envolveu visitas a campo, fotointerpretação e análise espacial em um ambiente de Sistema de Informações Geográficas (SIG). Para gerar o mapa de vulnerabilidade natural foram cruzados os mapas do meio físico (híbrido dos mapas de geologia, pedologia e geomorfologia) com o de vegetação, enquanto que o de vulnerabilidade ambiental consistiu no cruzamento do mapa de vulnerabilidade natural com o de uso e ocupação do solo. O mapa de vulnerabilidade natural demonstrou um predomínio de ambientes com vulnerabilidade baixa (29,6%) e média (42,4%), destacando dunas frontais e móveis como as áreas de maior vulnerabilidade. Tal resultado mostra a possibilidade de utilização e ocupação de até 72% do território, através de planejamento e ordenamento das atividades. O mapa de vulnerabilidade ambiental demonstrou uma preponderância de áreas com vulnerabilidade muito baixa (29,2%) e baixa (53,8%), indicando que a área de estudo foi pouco modificada pelo homem.

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