2,793 research outputs found

    Leveraging a Publish/Subscribe Fog System to Provide Collision Warnings in Vehicular Networks

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    [EN] Fog computing, an extension of the Cloud Computing paradigm where routers themselves may provide the virtualisation infrastructure, aims at achieving fluidity when distributing in-network functions, in addition to allowing fast and scalable processing, and exchange of information. In this paper we present a fog computing architecture based on a content island which interconnects sets of things to exchange and process data among themselves or with other content islands. We then present a use case that focuses on a smartphone-based forward collision warning application for a connected vehicle scenario. This application makes use of the optical sensor of smartphones to estimate the distance between the device itself and other vehicles in its field of view. The vehicle travelling directly ahead is identified relying on the information from the GPS, camera, and inter-island communication. Warnings are generated at both content islands, if the driver does not maintain a predefined safe distance towards the vehicle ahead. Experiments performed with the application show that with the developed method, we are able to estimate the distance between vehicles, and the inter-island communication has a very low overhead, resulting in improved performance. On comparing our proposed solution based on edge/fog computing with a cloud-based api, it was observed that our solution outperformed the cloud-based api, thus making us optimistic of the utility of the proposed architectureThis work was partially funding 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-I00Patra, S.; Manzoni, P.; Tavares De Araujo Cesariny Calafate, CM.; Zamora-Mero, WJ.; Cano, J. (2019). Leveraging a Publish/Subscribe Fog System to Provide Collision Warnings in Vehicular Networks. Sensors. 19(18):1-22. https://doi.org/10.3390/s19183852S1221918Vaquero, L. M., & Rodero-Merino, L. (2014). Finding your Way in the Fog. ACM SIGCOMM Computer Communication Review, 44(5), 27-32. doi:10.1145/2677046.2677052MQTT Version 3.1.1 http://docs.oasis-open.org/mqtt/mqtt/v3.1.1/os/mqtt-v3.1.1-os.docSultana, T., & Wahid, K. A. (2019). Choice of Application Layer Protocols for Next Generation Video Surveillance Using Internet of Video Things. IEEE Access, 7, 41607-41624. doi:10.1109/access.2019.2907525Mehmood, F., Ullah, I., Ahmad, S., & Kim, D. (2019). Object detection mechanism based on deep learning algorithm using embedded IoT devices for smart home appliances control in CoT. Journal of Ambient Intelligence and Humanized Computing. doi:10.1007/s12652-019-01272-8https://tools.ietf.org/html/rfc2616https://tools.ietf.org/html/rfc7252Volvo Official Website https://www.volvocars.com/Chang, B. R., Tsai, H. F., & Young, C.-P. (2010). Intelligent data fusion system for predicting vehicle collision warning using vision/GPS sensing. Expert Systems with Applications, 37(3), 2439-2450. doi:10.1016/j.eswa.2009.07.036Tan, H.-S., & Huang, J. (2006). DGPS-Based Vehicle-to-Vehicle Cooperative Collision Warning: Engineering Feasibility Viewpoints. IEEE Transactions on Intelligent Transportation Systems, 7(4), 415-428. doi:10.1109/tits.2006.883938Gelernter, D. (1985). Generative communication in Linda. ACM Transactions on Programming Languages and Systems, 7(1), 80-112. doi:10.1145/2363.2433Raspberry Pi Official Website https://www.raspberrypi.org/https://tools.ietf.org/html/rfc768Wallace, G. K. (1991). The JPEG still picture compression standard. Communications of the ACM, 34(4), 30-44. doi:10.1145/103085.103089Sauvola, J., & Pietikäinen, M. (2000). Adaptive document image binarization. Pattern Recognition, 33(2), 225-236. doi:10.1016/s0031-3203(99)00055-2Road Safety Authority of Ireland Suggest the Use of Two Second Rule http://www.rotr.ie/Rules_of_the_road.pdfOpenALPR Cloud-API Website https://www.openalpr.com/cloud-api.htmlPatra, S., Calafate, C. T., Cano, J.-C., & Manzoni, P. (2015). An ITS solution providing real-time visual overtaking assistance using smartphones. 2015 IEEE 40th Conference on Local Computer Networks (LCN). doi:10.1109/lcn.2015.736632

    Propagation of gravity waves and spread F in the low-latitude ionosphere over Tucumán, Argentina, by continuous Doppler sounding: first results

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    Results of systematic analysis of propagation directions and horizontal velocities of gravity waves (GWs) and spread F structures in low-latitude ionosphere (magnetic inclination ~27°) in Tucumán region, Argentina, are presented. Measurements were carried out by multipoint continuous Doppler system during 1 year from December 2012 to November 2013. It was found that meridian propagation of GWs dominated and that southward propagation prevailed in the local summer. Oblique spread structures observed in Doppler shift spectrograms and associated with spread F propagated roughly eastward at velocities from ~70 to ~180 m/s and were observed at night from ~ September to ~ March. The velocities were computed for 182 events and the azimuths for 64 events. Continuous Doppler sounding makes it possible to analyze more events compared to optical observations often used for propagation studies since the measurements do not depend on weather.Fil: Chum, J.. Institute of Atmospheric Physics; República ChecaFil: Miranda Bonomi, Fernando Alberto. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Departamento de Electricidad, Electrónica y Computación. Laboratorio de Telecomunicaciones; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Fišer, J.. Institute of Atmospheric Physics; República ChecaFil: Cabrera, M. A.. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Departamento de Electricidad, Electrónica y Computación. Laboratorio de Telecomunicaciones; Argentina. Universidad Tecnológica Nacional. Facultad Regional Tucuman; ArgentinaFil: Ezquer, Rodolfo Gerardo. Universidad Tecnológica Nacional. Facultad Regional Tucuman; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Departamento de Física. Laboratorio de Ionosfera; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Burešová, D.. Institute of Atmospheric Physics; República ChecaFil: Laštovička, J.. Institute of Atmospheric Physics; República ChecaFil: Baše, J.. Institute of Atmospheric Physics; República ChecaFil: Hruška, F.. Institute of Atmospheric Physics; República ChecaFil: Molina, Maria Graciela. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Departamento de Ciencias de la Computación; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ise, Juan Eduardo. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Departamento de Electricidad, Electrónica y Computación. Laboratorio de Telecomunicaciones; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cangemi, José Ignacio. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Departamento de Electricidad, Electrónica y Computación. Laboratorio de Telecomunicaciones; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Šindelářová, T.. Institute of Atmospheric Physics; República Chec

    Coulomb corrections to low energy antiproton annihilation cross sections on protons and nuclei

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    We calculate, in a systematic way, the enhancement effect on antiproton-proton and antiproton-nucleus annihilation cross sections at low energy due to the initial state electrostatic interaction between the projectile and the target nucleus. This calculation is aimed at future comparisons between antineutron and antiproton annihilation rates on different targets, for the extraction of pure isospin channels.Comment: 18 pages, 4 figures (latex format

    First determination of the one-proton induced Non-Mesonic Weak Decay width of p-shell {\Lambda}-Hypernuclei

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    Previous studies of proton and neutron spectra from Non-Mesonic Weak Decay of eight Lambda-Hypernuclei (A = 5-16) have been revisited. New values of the ratio of the two-nucleon and the one-proton induced decay widths, Gamma_2N/Gamma_p, are obtained from single proton spectra, Gamma_2N/Gamma_p = 0.50 +/- 0.24, and from neutron and proton coincidence spectra, Gamma_2N/Gamma_p = 0.36 +/- 0.14stat +0.05sys -0.04sys , in full agreement with previously published ones. With these values, a method is developed to extract the one-proton induced decay width in units of the free Lambda decay width, Gamma_p/Gamma_Lambda, without resorting to Intra Nuclear Cascade models but by exploiting only experimental data, under the assumption of a linear dependence on A of the Final State Interaction contribution. This is the first systematic determination ever done and it agrees within the errors with recent theoretical calculations.Comment: 16 pages, 3 figures, 2 table

    A practical guide to the simultaneous determination of protein structure and dynamics using metainference

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    Accurate protein structural ensembles can be determined with metainference, a Bayesian inference method that integrates experimental information with prior knowledge of the system and deals with all sources of uncertainty and errors as well as with system heterogeneity. Furthermore, metainference can be implemented using the metadynamics approach, which enables the computational study of complex biological systems requiring extensive conformational sampling. In this chapter, we provide a step-by-step guide to perform and analyse metadynamic metainference simulations using the ISDB module of the open-source PLUMED library, as well as a series of practical tips to avoid common mistakes. Specifically, we will guide the reader in the process of learning how to model the structural ensemble of a small disordered peptide by combining state-of-the-art molecular mechanics force fields with nuclear magnetic resonance data, including chemical shifts, scalar couplings and residual dipolar couplings.Comment: 49 pages, 9 figure

    Hot and repulsive traffic flow

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    We study a message passing model, applicable also to traffic problems. The model is implemented in a discrete lattice, where particles move towards their destination, with fluctuations around the minimal distance path. A repulsive interaction between particles is introduced in order to avoid the appearance of traffic jam. We have studied the parameter space finding regions of fluid traffic, and saturated ones, being separated by abrupt changes. The improvement of the system performance is also explored, by the introduction of a non-constant potential acting on the particles. Finally, we deal with the behavior of the system when temporary failures in the transmission occurs.Comment: 22 pages, uuencoded gzipped postscript file. 11 figures include

    Economic optimization of sugarcane-livestock integration for bioenergy expansion in Brazil.

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    This study compares and analyses the profitability of (i) a sugarcane ethanol distillery (producing ethanol and bioelectricity) and a typical livestock system without integration and (ii) an integrated system producing the same output of ethanol and beef with half of the area

    Overlapping redox zones control arsenic pollution in Pleistocene multi-layer aquifers, the Po Plain (Italy)

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    Understanding the factors that control As concentrations in groundwater is vital for supplying safe groundwater in regions with As-polluted aquifers. Despite much research, mainly addressing Holocene aquifers hosting young (12,000 yrs) groundwaters are not yet fully understood and so are assessed here through an evaluation of the redox properties of the system in a type locality, the Po Plain (Italy). Analyses of redox-sensitive species and major ions on 22 groundwater samples from the Pleistocene arsenic-affected aquifer in the Po Plain shows that groundwater concentrations of As are controlled by the simultaneous operation of several terminal electron accepters. Organic matter, present as peat, is abundant in the aquifer, allowing groundwater to reach a quasi-steady-state of highly reducing conditions close to thermodynamic equilibrium. In this system, simultaneous reduction of Fe-oxide and sulfate results in low concentrations of As (median 7 μg/L) whereas As reaches higher concentrations (median of 82 μg/L) during simultaneous methanogenesis and Fe-reduction. The position of well-screens is an additional controlling factor on groundwater As: short screens that overlap confining aquitards generate higher As concentrations than long screens placed away from them. A conceptual model for groundwater As, applicable worldwide in other Pleistocene aquifers with reducible Fe-oxides and abundant organic matter is proposed: As may have two concentration peaks, the first after prolonged Fe-oxide reduction and until sulfate reduction takes place, the second during simultaneous Fe-reduction and methanogenesis

    Securing combined Fog-to-Cloud systems: challenges and directions

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    Nowadays, fog computing is emerged for providing computational power closer to the users. Fog computing brings real-time processing, lowlatency, geo-distributed and etc. Although, fog computing do not come to compete cloud computing, it comes to collaborate. Recently, Fog-To-Cloud (F2C) continuum system is introduced to provide hierarchical computing system and facilitates fog-cloud collaboration. This F2C continuum system might encounter security issues and challenges due to their hierarchical and distributed nature. In this paper, we analyze attacks in different layer of F2C system and identify most potential security requirements and challenges for the F2C continuum system. Finally, we introduce the most remarkable efforts and trends for bringing secure F2C system.This work is supported by the H2020 projects mF2C (730929). It is also supported by the Spanish Ministry of Economy and Competitiveness and the European Regional Development Fund both under contract RTI2018-094532-B-100.Peer ReviewedPostprint (author's final draft
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