Graph-Based Detection of Seams In 360-Degree Images

In this paper, we propose an algorithm to detect a specific kind of distortions, referred to as seams, which commonly oc- cur when a 360-degree image is represented in planar domain by projecting the sphere to a polyhedron, e.g, via the Cube Map (CM) projection, and undergoes lossy compression. The proposed algorithm exploits a graph-based representation to account for the actual sampling density of the 360-degree sig- nal in the native spherical domain. The CM image is con- sidered as a signal lying on a graph defined on the spherical surface. The spectra of the processed and the original sig- nals, computed by applying the Graph Fourier Transform, are compared to detect the seams. To test our method a dataset of compressed CM 360-degree images, annotated by experts, has been created. The performance of the proposed algorithm is compared to those achieved by baseline metrics, as well as to the same approach based on spectral comparison but ignor- ing the spherical nature of the signal. The experimental results show that the proposed method has the best performance and can successfully detect up to approximately 90% of visible seams on our dataset

Visual Distortions in 360-degree Videos.

Omnidirectional (or 360°) images and videos are emergent signals being used in many areas, such as robotics and virtual/augmented reality. In particular, for virtual reality applications, they allow an immersive experience in which the user can interactively navigate through a scene with three degrees of freedom, wearing a head-mounted display. Current approaches for capturing, processing, delivering, and displaying 360° content, however, present many open technical challenges and introduce several types of distortions in the visual signal. Some of the distortions are specific to the nature of 360° images and often differ from those encountered in classical visual communication frameworks. This paper provides a first comprehensive review of the most common visual distortions that alter 360° signals going through the different processing elements of the visual communication pipeline. While their impact on viewers' visual perception and the immersive experience at large is still unknown-thus, it is an open research topic-this review serves the purpose of proposing a taxonomy of the visual distortions that can be encountered in 360° signals. Their underlying causes in the end-to-end 360° content distribution pipeline are identified. This taxonomy is essential as a basis for comparing different processing techniques, such as visual enhancement, encoding, and streaming strategies, and allowing the effective design of new algorithms and applications. It is also a useful resource for the design of psycho-visual studies aiming to characterize human perception of 360° content in interactive and immersive applications

A combined approach for comparative exoproteome analysis of Corynebacterium pseudotuberculosis

Background: Bacterial exported proteins represent key components of the host-pathogen interplay. Hence, we sought to implement a combined approach for characterizing the entire exoproteome of the pathogenic bacterium Corynebacterium pseudotuberculosis, the etiological agent of caseous lymphadenitis (CLA) in sheep and goats. Results: An optimized protocol of three-phase partitioning (TPP) was used to obtain the C. pseudotuberculosis exoproteins, and a newly introduced method of data-independent MS acquisition (LC-MSE) was employed for protein identification and label-free quantification. Additionally, the recently developed tool SurfG+ was used for in silico prediction of sub-cellular localization of the identified proteins. In total, 93 different extracellular proteins of C. pseudotuberculosis were identified with high confidence by this strategy; 44 proteins were commonly identified in two different strains, isolated from distinct hosts, then composing a core C. pseudotuberculosis exoproteome. Analysis with the SurfG+ tool showed that more than 75% (70/93) of the identified proteins could be predicted as containing signals for active exportation. Moreover, evidence could be found for probable non-classical export of most of the remaining proteins. Conclusions: Comparative analyses of the exoproteomes of two C. pseudotuberculosis strains, in addition to comparison with other experimentally determined corynebacterial exoproteomes, were helpful to gain novel insights into the contribution of the exported proteins in the virulence of this bacterium. The results presented here compose the most comprehensive coverage of the exoproteome of a corynebacterial species so far

MarinEye - A tool for marine monitoring

This work presents an autonomous system for marine integrated physical-chemical and biological monitoring – the MarinEye system. It comprises a set of sensors providing diverse and relevant information for oceanic environment characterization and marine biology studies. It is constituted by a physicalchemical water properties sensor suite, a water filtration and sampling system for DNA collection, a plankton imaging system and biomass assessment acoustic system. The MarinEye system has onboard computational and logging capabilities allowing it either for autonomous operation or for integration in other marine observing systems (such as Observatories or robotic vehicles. It was designed in order to collect integrated multi-trophic monitoring data. The validation in operational environment on 3 marine observatories: RAIA, BerlengasWatch and Cascais on the coast of Portugal is also discussed.info:eu-repo/semantics/publishedVersio

Transferência de calor através de paineis aglomerados de bagaço de cana, pinus e eucalipto : Heat transfer through against panels of sugar cane, pinus and eucaliptus

O objetivo deste trabalho foi determinar a transferência de calor, a temperatura de combustão e o calor específico de painéis de aglomerado feitos de bagaço de cana, pinus e eucalipto. Os painéis foram expostos a uma fonte de calor até a combustão e mantido por 30 minutos o fluxo de calor entre os materiais. Os resultados mostraram que a transferência de energia durante o aquecimento é maior para os painéis feitos de bagaço de cana-de-açúcar em comparação com os demais materiais

A validação da distribuição de espécies através de modelos preditivos: casos de estudo para a ilha da madeira

Os modelos preditivos de distribuição de espécies são uma importante ferramenta para lidar com a falta de informação biogeográfica existente para a maior parte dos taxa. Com esta técnica, estabelece -se uma relação entre a variável dependente (presença/ausência de uma espécie) e um conjunto de variáveis potencialmente preditoras, e é criado um mapa com a probabilidade de presença da espécie para uma determinada área de interesse. Neste capítulo, é usado o programa Maxent para criar modelos de distribuição potencial de um conjunto seleccionado de espécies, e os resultados obtidos são discutidos com base no conhecimento de especialistas nessas espécies.ABSTRACT: Predictive models of species distribution emerge as a valuable tool for tackling the lack of distributional information on most taxa. A function between the dependente variable (presence/absence of the species) and a set of potential predictors is established, and a map is generated for the focus area, indicating the probability of presence of the species. In this chapter, we use Maxent to develop potential distribution models for a number of selected species and we discuss the results on the basis of expert knowledge

La dinámica del contenido generado por el usuario en medios digitales de Iberoamérica y Estados Unidos

ES: En este trabajo se presenta un análisis comparativo del estatus o reconocimiento del CGU (contenido generado por el usuario) y de los niveles de control de la participación de los usuarios en las ediciones en línea de 24 diarios de Argentina, Colombia, México, Perú, Portugal, España, Estados Unidos y Venezuela. El estudio analiza las condiciones en las cuales los usuarios publican contenidos, tanto en términos de restricciones como del reconocimiento que reciben sus aportaciones por parte del medio informativo. "Periodismo participativo" se define como el resultado del incremento progresivo del intercambio de mensajes entre productores y consumidores en dos dimensiones: referencial y relacionalIn this paper we present a comparative analysis of UGC status and levels of control in 24 quality online mainstream newspapers from Argentina, Colombia, México, Perú, Portugal, Spain, US and Venezuela. The study addresses the conditions in which users provide content, in terms of constraint, and the recognition given by mainstream media to the users' activity. "Participatory journalism" is defined as the evolving materialization of an increase in message interchange activity between producers and consumers in two dimensions: content and relationshi

Abundância e sazonalidade de cigarrinhas (Hemiptera, Cicadellidae, Cicadellinae) em vegetação herbácea de pomar de laranja doce, no município de Montenegro, Estado do Rio Grande do Sul, Brasil.

O presente estudo teve por objetivo conhecer a flutuação populacional e a constância de cicadelíneos presentes na vegetação herbácea de um pomar de laranja doce (Citrus sinensis (L.) Osbeck), variedade Valência, em Montenegro, RS. O levantamento foi realizado com a metodologia da rede-de-varredura, tendo início em fevereiro de 2001 e finalizando-se em janeiro de 2002. Mensalmente foram coletadas dez amostras, sendo cada uma destas composta por 50 golpes de rede em movimento de avanço sobre a vegetação herbácea e cultura intercalar nas entrelinhas do pomar (n = 500 golpes/ocasião de coleta). No total foram coletados 928 cicadelíneos,pertencentes a nove espécies: Bucephalogonia xanthophis (Berg, 1879), Diedrocephala variegata(Fabricius, 1775), Hortensia similis(Walker, 1851), Macugonalia leucomelas (Walker, 1851), Parathona gratiosa (Blanchard, 1840), Plesiommata corniculata Young,1977, Sibovia sagata (Signoret, 1854), Sonesimia grossa (Signoret, 1854) e Tapajosa rubromarginata (Signoret, 1855). O período de maior abundância da comunidade de cicadelíneos foi durante a primavera e o verão. Hortensia similis e M. leucomelas foram as únicas espécies consideradas constantes durante o levantamento. A menor abundância dos cicadelíneos em abril e dezembro provavelmente devese a efeitos causados por fatores abióticos (pluviosidade) e aqueles relativos à estrutura da vegetação (altura das plantas) sobre a comunidade