906 research outputs found

    Semi-parametric multivariate modelling when the marginals are the same

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    A model is developed for multivariate distributions which have nearly the same marginals, up to shift and scale. This model, based on "interpolation" of characteristic functions, gives a new notion of "correlation". It allows straightforward nonparametric estimation of the common marginal distribution, which avoids the "curse of dimensionality" present when nonparametically estimating the full multivariate distribution. The method is illustrated with environmental monitoring network data, where multivariate modelling with common marginals is often appropriate

    Diseño de un sistema de mensajería instantánea para redes comunitarias

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    [ES] Cerca de 3.000 millones de personas en todo el mundo no pueden aprovechar ni siquiera los servicios de conectividad más básicos, ya que la mayoría de ellas viven en zonas rurales o países en vías de desarrollo. Incluso los servicios de mensajería más simples serian de gran ayuda, por ejemplo, para los agricultores que desean conocer el precio de las mercancías que les interesa vender o comprar antes de decidir si se emprende un viaje posiblemente largo, caro y agotador. La tecnología LoRa permite realizar enlaces de larga distancia con un consumo reducido de energía a bajo coste, siendo su principal limitación el escaso ancho de banda que ofrece. Con LoRa, los lugares remotos, como las zonas rurales, pueden beneficiarse de servicios basados en la conectividad que, de otro modo, serían imposibles. Nuestra propuesta entra en la categoría de redes comunitarias, en las que los usuarios construyen su propia red cuando no hay infraestructura comercial disponible. Además de la simple aplicación de mensajería, LoRa puede utilizarse para distribuir información de sensores a las comunidades o para proporcionar alertas de desastres o datos meteorológicos. Presentamos un protocolo flexible basado en la tecnología LoRa que permite la transferencia de "contenido" denominado LoRaCTP, el cual proporciona los mecanismos necesarios para que LoRa sea fiable, introduciendo una configuración de conexión ligera. Hemos diseñado este protocolo también como soporte de comunicación para las soluciones IoT basadas en edge computing, dada su estabilidad, el bajo consumo de energía y la posibilidad de cubrir largas distancias. Integramos una arquitectura que permite la recolección de datos de fuentes externas genéricas. Especialmente las fuentes de audio, apuntando a dos servicios básicos: un sistema de mensajería de voz que permite a los usuarios que no saben leer o escribir, realizar notas de voz, y un servicio de compresión de audio para extraer las principales características de la entrada de audio y utilizarla para desarrollar análisis de audio inteligente basado en Machine Learning. Combinamos IoT y Edge computing en un enfoque de innovación frugal, para proponer una solución "ingeniosa", en términos de utilización mínima de recursos y sostenibilidad, para construir un soporte básico para un sistema IoT en áreas rurales. Incluimos un proxy MQTT para integrar dispositivos de bajo coste y bajo consumo en un sistema de mensajería basado en LoRa. A través de una interfaz REST, mostramos cómo se puede usar nuestra plataforma para distribuir información de sensores de las comunidades rurales. Además, MQTT permite que estos datos se proporcionen a "lagos de datos" externos para que puedan usarse para tareas tales como informes, visualización, análisis avanzado y aprendizaje automático. Describimos una arquitectura genérica de edge/fog, utilizando microservicios, un sistema basado en MQTT que puede recopilar datos de ingreso, manejar su persistencia y coordinar la integración de datos con la nube utilizando un servicio específico llamado agregador. Las estaciones edge tienen un canal dedicado con el agregador que se basa en LoRa para permitir transmisiones de largo alcance con bajo consumo de energía.[CA] Prop de 3.000 milions de persones a tot el món no poden aprofitar ni tan sols els serveis de connectivitat més bàsics, ja que la majoria d'elles viuen en zones rurals o països en vies de desenvolupament. Fins i tot els serveis de missatgeria més simples serien de gran ajuda, per exemple, per als agricultors que desitgen conèixer el preu de les mercaderies que els interessa vendre o comprar abans de decidir si s'emprèn un viatge possiblement llarg, car i esgotador. La tecnologia LoRa permet realitzar enllaços de llarga distància amb un consum reduït d'energia a baix cost, sent la seua principal limitació l'escassa amplada de banda que ofereix. Amb LoRa, els llocs remots, com les zones rurals, poden beneficiar-se de serveis basats en la connectivitat que, d'una altra manera, serien impossibles. La nostra proposta entra en la categoria de xarxes comunitàries, en les quals els usuaris construeixen la seua pròpia xarxa quan no hi ha infraestructura comercial disponible. A més de la simple aplicació de missatgeria, LoRa pot utilitzarse per a distribuir informació de sensors a les comunitats o per a proporcionar alertes de desastres o dades meteorològiques. Presentem un protocol flexible basat en la tecnologia LoRa que permet la transferència de "contingut" denominat LoRaCTP, el qual proporciona els mecanismes necessaris perquè LoRa siga fiable, introduint una configuració de connexió lleugera. Hem dissenyat aquest protocol també com a suport de comunicació per a les solucions IoT basades en edge computing, donada la seua estabilitat, el baix consum d'energia i la possibilitat de cobrir llargues distàncies. Integrem una arquitectura que permet la recol·lecció de dades de fonts externes genèriques. Especialment, les fonts d'àudio, apuntant a dos serveis bàsics: un sistema de missatgeria de veu que permet als usuaris que no saben llegir o escriure realitzar notes de veu, i un servei de compressió d'àudio per a extraure les principals característiques de l'entrada d'àudio i utilitzar-la per a desenvolupar anàlisi d'àudio intel·ligent basat en Machine Learning. Combinem IoT i Edge computing en un enfocament d'innovació frugal, per a proposar una solució "enginyosa", en termes d'utilització mínima de recursos i sostenibilitat, per a construir un suport bàsic per a un sistema IoT en àrees rurals. Incloem un proxy MQTT per a integrar dispositius de baix cost i baix consum en un sistema de missatgeria basat en LoRa. A través d'una interfície REST, vam mostrar com es pot usar la nostra plataforma per a distribuir informació de sensors de les comunitats rurals. A més, MQTT permet que aquestes dades es proporcionen a "llacs de dades" externes perquè puguen usar-se per a tasques com ara informes, visualització, anàlisi avançada i aprenentatge automàtic. Descrivim una arquitectura genèrica de edge/fog, utilitzant microserveis, un sistema basat en MQTT que pot recopilar dades d'ingrés, manejar la seua persistència i coordinar la integració de dades amb el núvol utilitzant un servei específic anomenat agregador. Les estacions edge tenen un canal dedicat amb el agregador que es basa en LoRa per a permetre transmissions de llarg abast amb baix consum d'energia.[EN] Nearly 3 billion people around the world are unable to take advantage of even the most basic connectivity services, as most of them live in rural areas or developing countries. Even the simplest messaging services would be of great help, for example, to farmers who want to know the price of goods they are interested in selling or buying before deciding whether to embark on a possibly long, expensive and exhausting journey. LoRa technology enables long-distance links with reduced power consumption at low cost, its main limitation being the low bandwidth it offers. With LoRa, remote locations, such as rural areas, can benefit from connectivity-based services that would otherwise be impossible. Our proposal falls into the category of community networks, where users build their own network when commercial infrastructure is not available. In addition to a simple messaging application, LoRa can be used to distribute sensor information to communities or to provide disaster alerts or weather data. We present a flexible protocol based on LoRa technology that enables the transfer of "content" called LoRaCTP, which provides the necessary mechanisms for LoRa to be reliable, introducing a lightweight connection setup. We have designed this protocol also as a communication support for IoT solutions based on edge computing, given its stability, low power consumption and the possibility of covering long distances. Likewise, we integrated an architecture that allows data collection from generic external sources. Especially audio sources, targeting two basic services: a voice messaging system that allows users who cannot read or write to make voice notes, and an audio compression service to extract the main features of the audio input and use it to develop intelligent audio analytics based on Machine Learning. We combine IoT and Edge computing in a frugal innovation approach, to propose an "ingenious" solution, in terms of minimum resource utilization and sustainability, to build a basic support for an IoT system in rural areas. We include an MQTT proxy to integrate low-cost and low-power devices into a LoRa-based messaging system. Through a REST interface, we show how our platform can be used to distribute sensor information from rural communities. In addition, MQTT allows this data to be provided to external "data lakes" so that it can be used for tasks such as reporting, visualization, advanced analytics, and machine learning. We describe a generic edge/fog architecture, using microservices, an MQTT-based system that can collect ingress data, manage its persistence, and coordinate data integration with the cloud using a specific service called an aggregator. The edge stations have a dedicated channel with the aggregator that is based on LoRa to enable long-range transmissions with low power consumption.Agradezco al Gobierno de los Estados Unidos Mexicanos a través del Consejo Nacional de Ciencia y Tecnología (CONACYT) y al Gobierno de Chiapas mediante el Consejo de Ciencia y Tecnología del Estado de Chiapas (COCYTECH) por brindarme la oportunidad de mejoramiento profesional y académico por medio del programa de becas “CONACYT - Gobierno del Estado de Chiapas” en la convocatoria del 2017.Nakamura Pinto, MK. (2022). Diseño de un sistema de mensajería instantánea para redes comunitarias [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/18894

    Caffeine, but not other phytochemicals, in mate tea (Ilex paraguariensis St. Hilaire) attenuates high-fat-high-sucrose-diet-driven lipogenesis and body fat accumulation

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    Authors followed the guidelines of the National Institutes of Health guide for the care and use of Laboratory animals (NIH Publications No.8023, revised 1978)The objective was to examine the effectiveness of mate tea (MT, Ilex paraguariensis St. Hilaire) and caffeine from mate tea (MC) on in vitro lipid accumulation and in vivo diet-driven-obesity. MC and decaffeinated mate (DM) were obtained using supercritical CO2 extraction and mainly composed of caffeine and caffeoylquinic acids, respectively. MC reduced lipid accumulation (41%) via downregulation of fatty acid synthase (Fasn) (39%) in 3T3-L1 adipocytes. Rats fed a high-fat-high-sucrose-diet and 0.1% of caffeine from MC, MT, or DM. MC attenuated weight gain (16%) and body fat accumulation (22%). MC reduced Fasn expression in both adipose tissue (66%) and liver (37%). MC diminished pyruvate kinase (PK, 59%) and microsomal triglyceride transfer protein (MTP, 50%) hepatic expression. In silico, neochlorogenic acid interacted with PK and MTP allosteric sites. FAS β‐ketoacyl reductase domain showed the highest affinity to 3,5-dicaffeoylquinic acid. Caffeine suppressed lipid accumulation and body weight gain, through the modulation of lipogenic gene expressio

    A Low-Cost and Low-Power Messaging System Based on the LoRa Wireless Technology

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    [EN] In this paper we describe a low-cost and low-power consumption messaging system based on LoRa technology. More that one billion people worldwide cannot access even the most basic connectivity services. For them even simple messaging services would be of great help, for example to farmers wishing to know the price of goods they want to sell or buy before deciding whether a possibly long, expensive and exhausting trip is undertaken. LoRa networks allow for very long wireless links that can connect villages and towns. This system falls in the category of community networks, where users build their own network where no commercial infrastructure is available. In addition to the simple messaging application, LoRa can be used to distribute sensor information to communities or to provide disaster alerts or meteorological data.Moreno Cardenas, A.; Nakamura Pinto, MK.; Pietrosemoli, E.; Zennaro, M.; Rainone, M.; Manzoni, P. (2020). A Low-Cost and Low-Power Messaging System Based on the LoRa Wireless Technology. Mobile Networks and Applications (Online). 25(3):961-968. https://doi.org/10.1007/s11036-019-01235-5S96196825

    Adding voice messages to a low-cost long-range data messaging system

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    [EN] Remote locations in rural areas can benefit from any system that would provide some form of connectivity. In a previous work we described a low cost architecture that, thanks to the use of the LoRa technology, allowed long links using low energy and a cheap infrastructure. In this work we extend those results by adding the possibility to include generic external sources of data using an MQTT based interface. More specifically, we describe a voice messaging system that allows users that cannot read or write to send voice based messages. We describe how the system was integrated into the existing platform and present so me performance results. We consider that these results are promising and provide a tool that can offer a useful service at a low cost.This work was partially supported by the Ministerio de Ciencia, Innovación y Universidades, Programa Estatal de Investigación, Desarrollo e Innovación Orientada a los Retos de la Sociedad, Proyectos I+D+I 2018, Spain, under Grant RTI2018-096384-B-I00.Nakamura, K.; Manzoni, P.; Zennaro, M.; Cano, J.; Tavares De Araujo Cesariny Calafate, CM. (2020). Adding voice messages to a low-cost long-range data messaging system. Association for Computing Machinery (ACM). 42-47. https://doi.org/10.1145/3411170.3411238S424

    Constraint and gauge shocks in one-dimensional numerical relativity

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    We study how different types of blow-ups can occur in systems of hyperbolic evolution equations of the type found in general relativity. In particular, we discuss two independent criteria that can be used to determine when such blow-ups can be expected. One criteria is related with the so-called geometric blow-up leading to gradient catastrophes, while the other is based upon the ODE-mechanism leading to blow-ups within finite time. We show how both mechanisms work in the case of a simple one-dimensional wave equation with a dynamic wave speed and sources, and later explore how those blow-ups can appear in one-dimensional numerical relativity. In the latter case we recover the well known ``gauge shocks'' associated with Bona-Masso type slicing conditions. However, a crucial result of this study has been the identification of a second family of blow-ups associated with the way in which the constraints have been used to construct a hyperbolic formulation. We call these blow-ups ``constraint shocks'' and show that they are formulation specific, and that choices can be made to eliminate them or at least make them less severe.Comment: 19 pages, 8 figures and 1 table, revised version including several amendments suggested by the refere

    A LoRa-based protocol for connecting IoT edge computing nodes to provide small-data-based services

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    [EN] Data is becoming increasingly personal. Individuals regularly interact with a variety of structured data, ranging from SQLite databases on the phone to personal sensors and open government data. The ¿digital traces left by individuals through these interactions¿ are sometimes referred to as ¿small data¿. Examples of ¿small data¿ include driving records, biometric measurements, search histories, weather forecasts and usage alerts. In this paper, we present a flexible protocol called LoRaCTP, which is based on LoRa technology that allows data ¿chunks¿ to be transferred over large distances with very low energy expenditure. LoRaCTP provides all the mechanisms necessary to make LoRa transfer reliable by introducing a lightweight connection setup and allowing the ideal sending of an as-long-as necessary data message. We designed this protocol as communication support for small-data edge-based IoT solutions, given its stability, low power usage, and the possibility to cover long distances. We evaluated our protocol using various data content sizes and communication distances to demonstrate its performance and reliability.This work was partially supported by the "Conselleria de Innovacion, Universidades, Ciencia y Sociedad Digital", Proyectos AICO/2020, Spain, under Grant AICO/2020/302 and "Ministerio de Ciencia, Innovacion y Universidades, Programa Estatal de Investigacion, Desarrollo e Innovacion Orientada a los Retos de la Sociedad, Proyectos IDI 2018", Spain, under Grant RTI2018-096384-B-I00.Nakamura, K.; Manzoni, P.; Redondi, A.; Longo, E.; Zennaro, M.; Cano, J.; Tavares De Araujo Cesariny Calafate, CM. (2022). A LoRa-based protocol for connecting IoT edge computing nodes to provide small-data-based services. Digital Communications and Networks. 8(3):257-266. https://doi.org/10.1016/j.dcan.2021.08.0072572668
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