930 resultados para Edge detectors


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Most network operators have considered reducing LSR label spaces (number of labels used) as a way of simplifying management of underlaying virtual private networks (VPNs) and therefore reducing operational expenditure (OPEX). The IETF outlined the label merging feature in MPLS-allowing the configuration of multipoint-to-point connections (MP2P)-as a means of reducing label space in LSRs. We found two main drawbacks in this label space reduction a)it should be separately applied to a set of LSPs with the same egress LSR-which decreases the options for better reductions, and b)LSRs close to the edge of the network experience a greater label space reduction than those close to the core. The later implies that MP2P connections reduce the number of labels asymmetrically

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The rat lungworm Angiostrongylus cantonensis is a worldwide-distributed zoonotic nematode that can cause human eosinophilic meningoencephalitis. Here, for the first time, we report the isolation of A. cantonensis from Achatina fulica from two Brazilian states: Rio de Janeiro (specifically the municipalities of Barra do Piraí, situated at the Paraiba River Valley region and São Gonçalo, situated at the edge of Guanabara Bay) and Santa Catarina (in municipality of Joinville). The lungworms were identified by comparing morphological and morphometrical data obtained from adult worms to values obtained from experimental infections of A. cantonensis from Pernambuco, Brazil, and Akita, Japan. Only a few minor morphological differences that were determined to represent intra-specific variation were observed. This report of A. cantonensis in South and Southeast Brazil, together with the recent report of the zoonosis and parasite-infected molluscs in Northeast Brazil, provide evidence of the wide distribution of A. cantonensis in the country. The need for efforts to better understand the role of A. fulica in the transmission of meningoencephalitis in Brazil and the surveillance of molluscs and rodents, particularly in ports, is emphasized.

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Aquest projecte es centra principalment en el detector no coherent d’un GPS. Per tal de caracteritzar el procés de detecció d’un receptor, es necessita conèixer l’estadística implicada. Pel cas dels detectors no coherents convencionals, l’estadística de segon ordre intervé plenament. Les prestacions que ens dóna l’estadística de segon ordre, plasmada en la ROC, són prou bons tot i que en diferents situacions poden no ser els millors. Aquest projecte intenta reproduir el procés de detecció mitjançant l’estadística de primer ordre com a alternativa a la ja coneguda i implementada estadística de segon ordre. Per tal d’aconseguir-ho, s’usen expressions basades en el Teorema Central del Límit i de les sèries Edgeworth com a bones aproximacions. Finalment, tant l’estadística convencional com l’estadística proposada són comparades, en termes de la ROC, per tal de determinar quin detector no coherent ofereix millor prestacions en cada situació.

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The distribution of Lutzomyia longipalpis is heterogeneous with a pattern of high abundance areas (HAAs) embedded in a matrix of low abundance areas (LAAs). The objective of this study was to describe the variability in the abundance of Lu. longipalpis at two different spatial levels and to analyse the relationship between the abundance and multiple environmental variables. Of the environmental variables analysed in each household, the condition that best explained the differences in vector abundance between HAA-LAA was the variable "land_grass", with greater average values in the peridomestic environments within the LAA, and the variables "#sp tree", "#pots" and "dist_water" that were higher in the HAA. Of the environmental variables analysed in the patches, the variable "unpaved_streets" was higher in the LAAs and the variable "prop_inf_dogs" was higher in the HAAs. An understanding of the main environmental variables that influence the vector distribution could contribute to the development of strategies for the prevention and control of visceral leishmaniasis (VL). This is the first work in which environmental variables are analysed at the micro-scale in urban areas at the southern edge of the current range of Lu. longipalpis. Our results represent a significant contribution to the understanding of the abundance of the vector in the peridomestic habitats of the region.

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In this paper we present first results of the study of planktonic Foraminifera, large benthic Foraminifera and carbonate facies of La Désirade, aiming at a definition of the age and depositional environments of the Neogene carbonates of this island. The study of planktonic Foraminifera from the Detrital Offshore Limestones (DOL) of the Anciènne Carrière allows to constrain the biochronology of this formation to the lower Zone N19 and indicates a latest Miocene to early Pliocene (5.48 - 4.52 Ma) age. Large benthic Foraminifera were studied both as isolated and often naturally split specimens from the DOL, and in thin sections of limestones from the DOL and the Limestone Table (LT). The assemblages of Foraminifera include Nummulitidae, Amphisteginidae, Asterigerinidae, Peneroplidae, Soritidae, Rotalidae (Globigerinidae: Globigerinoides, Sphaeroidenellopsis, Orbulina) and incrusting Foraminifera (Homotrema and Sporadotrema). The genera Amphistegina, Archaias and Operculina are discussed. Concerning the Nummulitidae we include both "Paraspiroclypeus" chawneri and "Nummulites" cojimarensis, as well as a newly described species, Operculina desiradensis new species, in the genus Operculina, because the differences between these 3 species are rather on the specific than the generic level, while their morphology, studied by SEM, is compatible with the definition of the genus Operculina (D'Orbigny1826, emend. Hottinger 1977). The three species can be easily distinguished on the basis of their differences in spiral growth: while O. desiradensis has an overall logarithmic spiral growth, O. cojimarensis and especially O. chawneri show a tighter and more geometric spiral growth. O. cojimarensis and O. chawneri were originally described from Cuba in outcrops originally dated as Oligocene and later redated as early Pliocene. Therefore, O. chawneri was considered until now as restricted to the early Pliocene. However, in the absence of a detailed morphometric and biostratigraphic study of the Caribbean Neogene nummulitids, it is difficult to evaluate the biochronologic range of these species.The history of the carbonates begins with the initial tectonic uplift and erosion of the Jurassic igneous basement of La Désirade, that must have occurred at latest in late Miocene times, when sea-level oscillated around a long term stable mean. The rhythmic deposition of the Désirade Limestone Table (LT) can be explained by synsedimentary subsidence in a context of rapidly oscillating sea-level due to precession-driven (19-21 kyr) glacio-eustatic sea-level changes during the latest Miocene- Pliocene. Except for a thin reef cap present at the eastern edge of the LT, no other in-place reefal constructions have been observed in the LT. The DOL of western Désirade are interpreted as below wave base gravity deposits that accumulated beneath a steep fore-reef slope. They document the mobilisation of carbonate material (including Larger Foraminifera) from an adjacent carbonate platform by storms and their gravitational emplacement as debris and grain flows. The provenance of both the reefal carbonate debris and the tuffaceous components redeposited in the carbonates of La Désirade must be to the west, i. e. the carbonate platforms of Marie Galante and Grande Terre.

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Current research on sleep using experimental animals is limited by the expense and time-consuming nature of traditional EEG/EMG recordings. We present here an alternative, noninvasive approach utilizing piezoelectric films configured as highly sensitive motion detectors. These film strips attached to the floor of the rodent cage produce an electrical output in direct proportion to the distortion of the material. During sleep, movement associated with breathing is the predominant gross body movement and, thus, output from the piezoelectric transducer provided an accurate respiratory trace during sleep. During wake, respiratory movements are masked by other motor activities. An automatic pattern recognition system was developed to identify periods of sleep and wake using the piezoelectric generated signal. Due to the complex and highly variable waveforms that result from subtle postural adjustments in the animals, traditional signal analysis techniques were not sufficient for accurate classification of sleep versus wake. Therefore, a novel pattern recognition algorithm was developed that successfully distinguished sleep from wake in approximately 95% of all epochs. This algorithm may have general utility for a variety of signals in biomedical and engineering applications. This automated system for monitoring sleep is noninvasive, inexpensive, and may be useful for large-scale sleep studies including genetic approaches towards understanding sleep and sleep disorders, and the rapid screening of the efficacy of sleep or wake promoting drugs.

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Aquesta tesi explora la possibilitat de fer servir enllaços inductius per a una aplicació de l’automòbil on el cablejat entre la centraleta (ECU) i els sensors o detectors és difícil o impossible. S’han proposat dos mètodes: 1) el monitoratge de sensors commutats (dos possibles estats) via acoblament inductiu i 2) la transmissió mitjançant el mateix principi físic de la potència necessària per alimentar els sensors autònoms remots. La detecció d'ocupació i del cinturó de seguretat per a seients desmuntables pot ser implementada amb sistemes sense fils passius basats en circuits ressonants de tipus LC on l'estat dels sensors determina el valor del condensador i, per tant, la freqüència de ressonància. Els canvis en la freqüència són detectats per una bobina situada en el terra del vehicle. S’ha conseguit provar el sistema en un marge entre 0.5 cm i 3 cm. Els experiments s’han dut a terme fent servir un analitzador d’impedàncies connectat a una bobina primària i sensors comercials connectats a un circuit remot. La segona proposta consisteix en transmetre remotament la potència des d’una bobina situada en el terra del vehicle cap a un dispositiu autònom situat en el seient. Aquest dispositiu monitorarà l'estat dels detectors (d'ocupació i de cinturó) i transmetrà les dades mitjançant un transceptor comercial de radiofreqüència o pel mateix enllaç inductiu. S’han avaluat les bobines necessàries per a una freqüència de treball inferior a 150 kHz i s’ha estudiat quin és el regulador de tensió més apropiat per tal d’aconseguir una eficiència global màxima. Quatre tipus de reguladors de tensió s’han analitzat i comparat des del punt de vista de l’eficiència de potència. Els reguladors de tensió de tipus lineal shunt proporcionen una eficiència de potència millor que les altres alternatives, els lineals sèrie i els commutats buck o boost. Les eficiències aconseguides han estat al voltant del 40%, 25% i 10% per les bobines a distàncies 1cm, 1.5cm, i 2cm. Les proves experimentals han mostrat que els sensors autònoms han estat correctament alimentats fins a distàncies de 2.5cm.

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We analysed the composition of phyllosilicate minerals in sediments deposited by the Rhone and Oberaar glaciers (Swiss Alps), in order to identify processes and rates of biogeochemical weathering in relation to glacial erosion. The investigated sediments are part of chronosequences consisting of (A) suspended, "fresh" sediment in melt water; (B) terminal moraines from the Little Ice Age (LIA; approximately 1560-1850); and (C) tilts of the Younger Dryas interval (YD; approximately 11'500y BP). Secondary weathering products associated with the suspended sediment have not been observed: we therefore exclude intermittent subglacial storage and weathering of this material and assume that the suspended sediment is directly derived from mechanically abraded bedrock. This implies that biogeochemical weathering processes started once the glacially-derived sediment was deposited in the proglacial area. The combination of a developing vegetation cover, the generally high permeability allowing the percolation of precipitation, and the chemical reactivity related to the dominance of fine-grained material (<63 pm) drives the weathering process and the initial Umbrepts present in LIA profiles undergo podzolisation and lead to the formation of Humods observed in YD profiles. Systematic XRD analyses of these chronosequences show a progressive decrease in biotite contents and a concomitant increase in pedogenically formed vermiculite with increasing sediment age. Biotite contents decrease by 25-50% in the upper 30 cm of the moraines after 145-275 yr in the proglacial environment. Biotite weathering rates are calculated using the difference in the biotite content between unweathered and weathered glacial sediments within the investigated profiles. The reactive mineral surface area is estimated geometrically, both with regards to the total relative surface (WRT) as well as to the relative edge surface (WRE). WRT Biotite weathering rates are estimated as 10(-13)-10-(15) mol(biotite) m(biotite)(-2) s(-1). WRE Biotite weathering rates are on the order of 10(-13)-10(-14) mol(biotite) m(biotite)(-2) s(-1). Biotite weathering rates obtained by this study are in the order of one magnitude higher in comparison to other published field-based weathering rates. Using biotite as an indicator, we therefore suggest that glacially-derived material in the area of the Oberaar and Rhone glaciers is generally subjected to enhanced biogeochemical weathering, starting immediately after deposition in the proglacial zone and subsequently continuing for thousands of years after glacier retreat.

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El poder de l'Estat i la sobirania tradicional s'està deteriorant de manera constant, sobretot en termes de la provisió de certs béns públics fonamentals. Els Estats, en particular, són incapaços de manejar el coneixement i la informació que és essencial per mantenir la competitivitat i la sostenibilitat en una economia interdependent. Estructures fiables de la governança mundial i la cooperació internacional estan lluny de ser establertes. Energia com a problema a les agendes p dels governs, les empreses privades i la societat civil és un exemple manifest d'aquesta dinàmica.. L'actual sistema de governança mundial d'energia implica accions polítiques disperses per actors divers. L'Agència Internacional de l'Energia té un paper destacat, però està debilitat per la seva composició limitada i basada en el coneixement- epistèmic en lloc del material o executiu. Aquest treball sosté que ni la mida ni nombre de membres disponibles estan dificultant la governabilitat mundial d'energia. Més aviat, l'energia és una sèrie de béns públics que es troben als llimbs, on els estats no poden pagar la seva disposició, així com els diversos interessos impedir l'establiment d'una autoritat internacional. Després de la introducció de la teoria del règim internacional i el concepte de coneixement basats en les comunitats epistèmiques, l'article revisa l'estat actual de la governabilitat de l'energia mundia. A continuació es presenta una comparació d'aquesta estructura amb els règims de govern nacional i regional, d'una banda, i amb règims globals ambientals i de salut, de l'altra

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We propose a segmentation method based on the geometric representation of images as 2-D manifolds embedded in a higher dimensional space. The segmentation is formulated as a minimization problem, where the contours are described by a level set function and the objective functional corresponds to the surface of the image manifold. In this geometric framework, both data-fidelity and regularity terms of the segmentation are represented by a single functional that intrinsically aligns the gradients of the level set function with the gradients of the image and results in a segmentation criterion that exploits the directional information of image gradients to overcome image inhomogeneities and fragmented contours. The proposed formulation combines this robust alignment of gradients with attractive properties of previous methods developed in the same geometric framework: 1) the natural coupling of image channels proposed for anisotropic diffusion and 2) the ability of subjective surfaces to detect weak edges and close fragmented boundaries. The potential of such a geometric approach lies in the general definition of Riemannian manifolds, which naturally generalizes existing segmentation methods (the geodesic active contours, the active contours without edges, and the robust edge integrator) to higher dimensional spaces, non-flat images, and feature spaces. Our experiments show that the proposed technique improves the segmentation of multi-channel images, images subject to inhomogeneities, and images characterized by geometric structures like ridges or valleys.

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Time is embedded in any sensory experience: the movements of a dance, the rhythm of a piece of music, the words of a speaker are all examples of temporally structured sensory events. In humans, if and how visual cortices perform temporal processing remains unclear. Here we show that both primary visual cortex (V1) and extrastriate area V5/MT are causally involved in encoding and keeping time in memory and that this involvement is independent from low-level visual processing. Most importantly we demonstrate that V1 and V5/MT are functionally linked and temporally synchronized during time encoding whereas they are functionally independent and operate serially (V1 followed by V5/MT) while maintaining temporal information in working memory. These data challenge the traditional view of V1 and V5/MT as visuo-spatial features detectors and highlight the functional contribution and the temporal dynamics of these brain regions in the processing of time in millisecond range. The present project resulted in the paper entitled: 'How the visual brain encodes and keeps track of time' by Paolo Salvioni, Lysiann Kalmbach, Micah Murray and Domenica Bueti that is now submitted for publication to the Journal of Neuroscience.

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PURPOSE: : We describe a retinal endovascular fibrinolysis technique to directly reperfuse experimentally occluded retinal veins using a simple micropipette. METHODS: : Retinal vein occlusion was photochemically induced in 12 eyes of 12 minipigs: after intravenous injection of 10% fluorescein (1-mL bolus), the targeted retinal vein segment was exposed to thrombin (50 units) and to Argon laser (100-200 mW) through a pars plana approach. A beveled micropipette with a 30-μm-diameter sharp edge was used for micropuncture of the occluded vein and endovascular microinjection of tissue plasminogen activator (50 μg/mL) in 11 eyes. In one control eye, balanced salt solution was injected. The lesion site was examined histologically. RESULTS: : Retinal vein occlusion was achieved in all cases. Endovascular microinjection of tissue plasminogen activator or balanced salt solution led to reperfusion of the occluded retinal vein in all cases. Indicative of successful reperfusion were the following: continuous endovascular flow, unaffected collateral circulation, no optic disk ischemia, and no venous wall bleeding. However, balanced salt solution injection was accompanied by thrombus formation at the punctured site, whereas no thrombus was observed with tissue plasminogen activator injection. CONCLUSION: : Retinal endovascular fibrinolysis constitutes an efficient method of micropuncture and reperfusion of an experimentally occluded retinal vein. Thrombus formation at the punctured site can be prevented by injection of tissue plasminogen activator.

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Next Generation Access Networks (NGAN) are the new step forward to deliver broadband services and to facilitate the integration of different technologies. It is plausible to assume that, from a technological standpoint, the Future Internet will be composed of long-range high-speed optical networks; a number of wireless networks at the edge; and, in between, several access technologies, among which, the Passive Optical Networks (xPON) are very likely to succeed, due to their simplicity, low-cost, and increased bandwidth. Among the different PON technologies, the Ethernet-PON (EPON) is the most promising alternative to satisfy operator and user needs, due to its cost, flexibility and interoperability with other technologies. One of the most interesting challenges in such technologies relates to the scheduling and allocation of resources in the upstream (shared) channel. The aim of this research project is to study and evaluate current contributions and propose new efficient solutions to address the resource allocation issues in Next Generation EPON (NG-EPON). Key issues in this context are future end-user needs, integrated quality of service (QoS) support and optimized service provisioning for real time and elastic flows. This project will unveil research opportunities, issue recommendations and propose novel mechanisms associated with the convergence within heterogeneous access networks and will thus serve as a basis for long-term research projects in this direction. The project has served as a platform for the generation of new concepts and solutions that were published in national and international conferences, scientific journals and also in book chapter. We expect some more research publications in addition to the ones mentioned to be generated in a few months.

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Actualment ens trobem en un món on tot gira al voltant de les noves tecnologies, i un pilar fonamental és l'oci i l'entreteniment. Això engloba principalment les indústries del cinema, videojocs i realitat virtual. Un dels problemes que tenen aquestes indústries és com crear l'escenari on es produeix la història. L'objectiu d'aquest projecte de final de carrera és crear una eina integrada al skylineEngine, que serveixi per crear edificis de manera procedural, on l'usuari pugui definir l'estètica d'aquest edifici, introduint la seva planta i els perfils adequats. El que s'implementarà serà una eina de modelatge per a dissenyadors, que a partir d'una planta i perfils pugui crear l'edifici.Aquest projecte es desenvoluparà a sobre del mòdul de generació d'edificis del skylineEngine, una eina pel modelatge de ciutats que s'executa sobre el Houdini 3D, que és una plataforma genèrica pel modelatge procedural d'objectes.El desenvolupament d'aquest projecte implica:• Estudi de la plataforma de desenvolupament Houdini 3D i de les llibreries necessàries per la incorporació de scripts Python. Estudi de les EEDD internes de Houdini.• Aprendre i manejar el llenguatge de programació Python.• Estudi del codi de l'article Interactive Architectural Modeling with Procedural Extrusions, per en Tom Kelly i en Peter Wonka, publicat a la revista ACM Transactions on Graphics (2011).• Desenvolupament d'algorismes de conversió de geometria d'una estructura tipus face-vertex a una de tipus half-edge, i viceversa.• Modificació del codi Java per acceptar crides sense interfície d'usuari i amb estructures de dades generades des de Python.• Aprendre el funcionament de la llibreria JPype per permetre enllaçar el Java dins el Python.• Estudi del skylineEngine i de les llibreries per la creació d'edificis.• Integració del resultat dintre del skylineEngine.• Verificació i ajust de les regles i paràmetres de la simulació per a diferents edificis