2,517 research outputs found

    Visualization of Skewed Data: A Tool in R

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    In this work we present a visualization tool specifically tailored to deal with skewed data. The technique is based upon the use of two types of notched boxplots (the usual one, and one which is tuned for the skewness of the data), the violin plot, the histogram and a nonparametric estimate of the density. The data is assumed to lie on the same line, so the plots are compatible. We show that a good deal of information can be extracted from the inspection of this tool; in particular, we apply the technique to analyze data from synthetic aperture radar images. We provide the implementation in R.Comment: Submitted to the Revista Colombiana de Estad\'istic

    Classification and Verification of Online Handwritten Signatures with Time Causal Information Theory Quantifiers

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    We present a new approach for online handwritten signature classification and verification based on descriptors stemming from Information Theory. The proposal uses the Shannon Entropy, the Statistical Complexity, and the Fisher Information evaluated over the Bandt and Pompe symbolization of the horizontal and vertical coordinates of signatures. These six features are easy and fast to compute, and they are the input to an One-Class Support Vector Machine classifier. The results produced surpass state-of-the-art techniques that employ higher-dimensional feature spaces which often require specialized software and hardware. We assess the consistency of our proposal with respect to the size of the training sample, and we also use it to classify the signatures into meaningful groups.Comment: Submitted to PLOS On

    Circuit Theory

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    Contains reports on one research project

    Pinworms of the red howler monkey (Alouatta seniculus) in Colombia. Gathering the pieces of the pinworm-primate puzzle

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    Pinworms of primates are believed to be highly host specific parasites, forming co-evolutionary associations with their hosts. In order to assess the strength and reach of such evolutionary links, we need to have a broad understanding of the pinworm diversity associated with primates. Here, we employed an integrative taxonomic approach to assess pinworm diversity in red howler monkeys in Colombia. Molecular and morphological evidence validate the presence of at least four different species of Trypanoxyuris occurring in red howler monkeys: T. minutus, a widely distributed species, and three new species, T. seunimiii n. sp., T. kemuimae n. sp. and T. kotudoi n. sp. The mitochondrial COI gene and the 28S ribosomal gene were used for phylogenetic assessments through Bayesian inference. The three new species were morphologically distinct and formed reciprocally monophyletic lineages. Further molecular lineage subdivision in T. minutus and T. kotudoi n. sp. without morphological correspondence, suggests the potential scenario for the existence of cryptic species. Phylogenetic relationships imply that the different species of Trypanoxyuris occurring in each howler monkey species were acquired through independent colonization events. On-going efforts to uncover pinworm diversity will allow us to test the degree of host specificity and the co-phylogenetic hypothesis, as well as to further unravel the primate-pinworm evolutionary history puzzle

    Linking ICTs and Climate Change Adaptation: A Conceptual Framework for eResilience and eAdaptation

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    Also published as University of Manchester, Climate change, innovation and ICTs paper no. 2The aim of this paper is to set out a conceptual foundation that links climate change, livelihoods vulnerability, and the potential of information and communication technologies (ICTs) in supporting systemic resilience. A systemic perspective allows for the identification of key components, processes and properties, as well as the feedback and interactions that play a role in the realisation of adaptation processes in vulnerable settings. The concept of e-resilience is defined as a property of livelihood systems by which ICTs interact with a set of resilience sub-properties, enabling the system to adapt to the effects of climate change
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