89 research outputs found

    The heterogeneous gas with singular interaction: Generalized circular law and heterogeneous renormalized energy

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    We introduce and analyze dd dimensional Coulomb gases with random charge distribution and general external confining potential. We show that these gases satisfy a large deviations principle. The analysis of the minima of the rate function (which is the leading term of the energy) reveals that at equilibrium, the particle distribution is a generalized circular law (i.e. with spherical support but non-necessarily uniform distribution). In the classical electrostatic external potential, there are infinitely many minimizers of the rate function. The most likely macroscopic configuration is a disordered distribution in which particles are uniformly distributed (for d=2d=2, the circular law), and charges are independent of the positions of the particles. General charge-dependent confining potentials unfold this degenerate situation: in contrast, the particle density is not uniform, and particles spontaneously organize according to their charge. In that picture the classical electrostatic potential appears as a transition at which order is lost. Sub-leading terms of the energy are derived: we show that these are related to an operator, generalizing the Coulomb renormalized energy, which incorporates the heterogeneous nature of the charges. This heterogeneous renormalized energy informs us about the microscopic arrangements of the particles, which are non-standard, strongly depending on the charges, and include progressive and irregular lattices.Comment: 26 pages, 10 figure

    The past distribution of pinus nigra arnold in northern iberia. Contribution from its macroremains.

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    The presence of Pinus nigra in central Spain, where its natural populations are very rare, has led to different interpretations of the current vegetation dynamics. Complementary to the available palynological evidence, macroremains provide local information of high taxonomic resolution that helps to reconstruct the palaeobiogeography of a given species. Here we present new macrofossil data from Tubilla del Lago, a small palaeolake located at the eastern part of the northern Iberian Meseta. We identified 17 wood samples and 71 cones on the basis of their wood anatomy and morphology, respectively. S ome of the fossil samples were radiocarbon dated (~4.230-3210 years cal BP). The results demonstrate the Holocene presence of P. nigra in the study area, where it is currently extinct. This evidence, together with other published palaeobotanical studies, indicates that the forests dominated by P. nigra must have had a larger importance on the landscape prior to the anthropogenic influence on the northern Iberian Meseta

    Active video summarization: Customized summaries via on-line interaction with the user

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    To facilitate the browsing of long videos, automatic video summarization provides an excerpt that represents its content. In the case of egocentric and consumer videos, due to their personal nature, adapting the summary to specific user's preferences is desirable. Current approaches to customizable video summarization obtain the user's preferences prior to the summarization process. As a result, the user needs to manually modify the summary to further meet the preferences. In this paper, we introduce Active Video Summarization (AVS), an interactive approach to gather the user's preferences while creating the summary. AVS asks questions about the summary to update it on-line until the user is satisfied. To minimize the interaction, the best segment to inquire next is inferred from the previous feedback. We evaluate AVS in the commonly used UTEgo dataset. We also introduce a new dataset for customized video summarization (CSumm) recorded with a Google Glass. The results show that AVS achieves an excellent compromise between usability and quality. In 41% of the videos, AVS is considered the best over all tested baselines, including summaries manually generated. Also, when looking for specific events in the video, AVS provides an average level of satisfaction higher than those of all other baselines after only six questions to the user

    Evaluation of the R&R and the compatibility index for non-independent measurements

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    This paper describes the methodology of the compatibility criteria En and the methodology of repeatability and reproducibility (R&R) throught the average and range method. With this paper we will use the methodology R&R for the evaluation of the compatibility criteria between the staff of the laboratories, where independent measurements are not insured.Postprint (published version

    Evaluation of the R&R and the compatibility index for non-independent measurements

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    This paper describes the methodology of the compatibility criteria “En” and the methodology of R&R. With this paper we’ll use the methodology R&R for the evaluation of the compatibility criteria between the staff of the laboratories, where independent measurements aren’t insured.Postprint (published version

    Predicting visual context for unsupervised event segmentation in continuous photo-streams

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    Segmenting video content into events provides semantic structures for indexing, retrieval, and summarization. Since motion cues are not available in continuous photo-streams, and annotations in lifelogging are scarce and costly, the frames are usually clustered into events by comparing the visual features between them in an unsupervised way. However, such methodologies are ineffective to deal with heterogeneous events, e.g. taking a walk, and temporary changes in the sight direction, e.g. at a meeting. To address these limitations, we propose Contextual Event Segmentation (CES), a novel segmentation paradigm that uses an LSTM-based generative network to model the photo-stream sequences, predict their visual context, and track their evolution. CES decides whether a frame is an event boundary by comparing the visual context generated from the frames in the past, to the visual context predicted from the future. We implemented CES on a new and massive lifelogging dataset consisting of more than 1.5 million images spanning over 1,723 days. Experiments on the popular EDUB-Seg dataset show that our model outperforms the state-of-the-art by over 16% in f-measure. Furthermore, CES' performance is only 3 points below that of human annotators.Comment: Accepted for publication at the 2018 ACM Multimedia Conference (MM '18

    Late Holocene vegetation dynamics in response to human activities in the Teleno Mountain Range (NW Iberia)

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    Teleno Mountains are a good area to address these questions. Today are almost completely deforested, and it is commonly assumed that Romans were the culture responsible of this situation, as they developed important mining activities all over this mountains. Our main aim has been to track human impact on the landscape of this Iberian mountainous area along the second half of the Holocene and confirm the role of Roman culture in this process. For this purpose, we have obtained a new palaeoecological record from the Teleno Mountain

    Long-term persistence of Mediterranean pine forests in the Duero Basin (central Spain) during the Holocene: The case of Pinus pinaster Aiton

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    In the southern Duero Basin of central Spain, there are vast areas of aeolian sand sheets and dune fields. A comprehensive survey of the sand quarries in this area identified a number of palaeosols in sedimentary sequences. The identification and AMS radiocarbon dating of soil charcoal fragments collected in these palaeosols indicate the persistence of Pinus pinaster in this area throughout most of the Holocene. Although potential natural vegetation models have usually considered the Pinus pinaster forests in this inland area of artificial origin, soil charcoal analysis provides firm evidence of a natural origin. Our data fit perfectly with the pattern of Holocene vegetation development for inland areas of Iberia, which are characterised by stability of pine forests throughout the Holocene. Finally, the growing body of palaeobotanical evidence from Iberia (macrofossils and pollen) is contributing to improve our knowledge of P. pinaster ecology, showing that this species has been present in most Iberian regions during the Holocene, where it has inhabited areas characterised by a very diverse set of climatic and soil conditions

    Conservación del elemento boreo-alpino del sistema central: Microrreserva de los circos de Cerezuelo y Buitrera

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    El entorno del Pico del Lobo es uno de los enclaves del Sistema Central con una mayor diversidad de taxones eurosiberianos y boreo-alpinos, presentando además diversos hábitats de carácter atlántico y orófilo bien conservados. La presencia en la zona de dos especies del Catálogo de Flora Protegida regional,Swertia perennis L. y Huperzia selago (L.) Bernh. ex Schrank & Mart .subsp. selago y en el marco del Decreto 63/2007 de la Junta de Castilla y León, se propone la creación de la presente Microrreserva de Flora
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