323 research outputs found

    Hábitos alimentarios de Sigaria lateralis (Heteroptera, Corixidae)

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    Approximation of proximities by aggregating T-indistinguishability operators

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    For a continuous Archimedean t-norm T a method to approximate a proximity relation R (i.e. a reflexive and symmetric fuzzy relation) by a T-transitive one is provided. It consists of aggregating the transitive closure R of R with a (maximal) T-transitive relation B contained in R using a suitable weighted quasi-arithmetic mean to maximize the similarity or minimize the distance to R.Peer Reviewe

    Combining Fine- and Coarse-Grained Classifiers for Diabetic Retinopathy Detection

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    Visual artefacts of early diabetic retinopathy in retinal fundus images are usually small in size, inconspicuous, and scattered all over retina. Detecting diabetic retinopathy requires physicians to look at the whole image and fixate on some specific regions to locate potential biomarkers of the disease. Therefore, getting inspiration from ophthalmologist, we propose to combine coarse-grained classifiers that detect discriminating features from the whole images, with a recent breed of fine-grained classifiers that discover and pay particular attention to pathologically significant regions. To evaluate the performance of this proposed ensemble, we used publicly available EyePACS and Messidor datasets. Extensive experimentation for binary, ternary and quaternary classification shows that this ensemble largely outperforms individual image classifiers as well as most of the published works in most training setups for diabetic retinopathy detection. Furthermore, the performance of fine-grained classifiers is found notably superior than coarse-grained image classifiers encouraging the development of task-oriented fine-grained classifiers modelled after specialist ophthalmologists.Comment: Pages 12, Figures

    Investigating cortico-subcortical circuits during auditory sensory attenuation: A combined magnetoencephalographic and dynamic causal modeling study

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    Sensory attenuation refers to the decreased intensity of a sensory percept when a sensation is self‐generated compared with when it is externally triggered. However, the underlying brain regions and network interactions that give rise to this phenomenon remain to be determined. To address this issue, we recorded magnetoencephalographic (MEG) data from 35 healthy controls during an auditory task in which pure tones were either elicited through a button press or passively presented. We analyzed the auditory M100 at sensor‐ and source‐level and identified movement‐related magnetic fields (MRMFs). Regression analyses were used to further identify brain regions that contributed significantly to sensory attenuation, followed by a dynamic causal modeling (DCM) approach to explore network interactions between generators. Attenuation of the M100 was pronounced in right Heschl's gyrus (HES), superior temporal cortex (ST), thalamus, rolandic operculum (ROL), precuneus and inferior parietal cortex (IPL). Regression analyses showed that right postcentral gyrus (PoCG) and left precentral gyrus (PreCG) predicted M100 sensory attenuation. In addition, DCM results indicated that auditory sensory attenuation involved bi‐directional information flow between thalamus, IPL, and auditory cortex. In summary, our data show that sensory attenuation is mediated by bottom‐up and top‐down information flow in a thalamocortical network, providing support for the role of predictive processing in sensory‐motor system

    A logical study of local and global graded similarities

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    In this work we study the relationship between global and local similarities in the graded framework of fuzzy class theory (FCT), in which there already exists a graded notion of similarity. In FCT we can express the fact that a fuzzy relation is reflexive, symmetric, or transitive up to a certain degree, and similarity is defined as a first-order sentence, which is the fusion of three sentences corresponding to the graded notions of reflexivity, symmetry, and transitivity. This allows us to speak in a natural way of the degree of similarity of a relation. We consider global similarities defined from local similarities using t-norms as aggregation operators, and we obtain some results in the framework of FCT that, adequately interpreted, allow us to say that when we take a t-norm as an aggregation operator, the properties of reflexivity, symmetry, and transitivity of fuzzy binary relations are inherited from the local to the global level, and that the global similarity is a congruence if some of the local similarities are congruence

    Learning Task-Specific Generalized Convolutions in the Permutohedral Lattice

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    Dense prediction tasks typically employ encoder-decoder architectures, but the prevalent convolutions in the decoder are not image-adaptive and can lead to boundary artifacts. Different generalized convolution operations have been introduced to counteract this. We go beyond these by leveraging guidance data to redefine their inherent notion of proximity. Our proposed network layer builds on the permutohedral lattice, which performs sparse convolutions in a high-dimensional space allowing for powerful non-local operations despite small filters. Multiple features with different characteristics span this permutohedral space. In contrast to prior work, we learn these features in a task-specific manner by generalizing the basic permutohedral operations to learnt feature representations. As the resulting objective is complex, a carefully designed framework and learning procedure are introduced, yielding rich feature embeddings in practice. We demonstrate the general applicability of our approach in different joint upsampling tasks. When adding our network layer to state-of-the-art networks for optical flow and semantic segmentation, boundary artifacts are removed and the accuracy is improved.Comment: To appear at GCPR 201

    Toda la ciudad era un paisaje. Naturaleza, arquitectura y pintura en la obra de Wang Shu

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    Según Wang Shu, su arquitectura produce una experiencia análoga a la que ofrece la contemplación de la pintura tradicional china. Esta se diferencia del arte occidental en que no trata de expresar la sensibilidad visual de su autor a través de la descripción de la luz, el espacio y los objetos. No define los temas a través del color sino perfilándolos con líneas oscuras y unas pocas tonalidades. El pintor no trabaja del natural; normalmente es, también, filósofo y poeta, además de dominar muchas otras disciplinas técnicas y humanísticas; vive aislado en los parajes elegidos antes de pintarlos, para captar el funcionamiento estructural del mundo natural del que forma parte y compartir después, a través de su arte, ese conocimiento. Provocar ese mismo tipo de vivencias es también para Wang Shu el principal propósito de su arquitectura

    STECF Multiannual management plans SWW and NWW (STECF-15-08)

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    The STECF was tasked with an analysis of the likely effects of proposed management plans for the Southwestern (Bay of Biscay and Iberia) and Northwestern (Celtic sea) waters. Quantitative analyses were carried out to compare the likely effect of those management plans and of the direct application of the CFP on both stocks and fleets involved in these fisheries. Based on the results of simulations of the provisions of the proposed management plans, STECF concluded that, setting fishing opportunities in line with single-species FMSY ranges will provide managers with additional flexibility compared to the basic provisions of the 2013 CFP. Such flexibility is likely to help alleviate the problem of mismatches in quota availability in mixed-species fisheries thereby reducing the risk of early closure of some fisheries due to choke species. Adopting FMSY ranges will therefore increase the likelihood that desired exploitation rates will be achieved and will reduce the risk that some fishing fleets will go out of business. STECF considers that it is crucial that managers take note that persistent fishing at the upper limits of the FMSY ranges across all or most stocks simultaneously negates the flexibility introduced by the FMSY ranges and greatly increases the risk of overfishing. Such an approach will also increase the risk that the objectives of the CFP will not be achieved. STECF concludes that single species biomass safeguards for all stocks should be maintained to provide a basic level of protection. STECF notes that for the fleets affected by the SWW MAP, those providing the highest employment are generally not dependent to a great extent on the species that will be regulated through the MAP proposals. STECF notes that in the NWW there are some fleets which provide significant levels of employment and seem to be very dependent on the species that will be regulated through the MAP proposals. Nevertheless, there are a number of fleets in the NWW area that are not included in the employment analysis because of an absence of appropriate data. .Regarding the number and scope of MAPs as currently defined, STECF considers that a MAP covering a wider geographic area has advantages in terms of reducing management overheads and avoiding multiple regulations affecting the sector. A larger MAP area however, may have disadvantages associated with reducing the emphasis on local management measures and this may discourage the involvement of stakeholders, although this effect will depend on how the process of regionalization operates within the MAP. To evaluate the question of whether management of the species that drive the fisheries adequately allows for the management of by-catch species, the EWG carried out an analysis of correlations between catches of driver species identified in the plan and a variety of by-catch species. The analysis suggested only limited correlation. In view of this, the STECF notes that it is unlikely that relying on the TAC of the driver species to manage other species will be effective, in accordance with CFP requirements. STECF however notes that when analysis was performed at the fleet level, there were more obvious correlations, suggesting some scope to use fleet related management measures for the driver species as a way of managing some of the bycatch species. STECF therefore concludes that management of exploitation rates of non-driver (or bycatch) species is unlikely to occur as an automatic consequence of the management of the main (driver) stocks by TAC considered in the MAP.DG MAR
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