3,994 research outputs found

    Security Improvements for Connected Vehicles Position-Based Routing

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    The constant growing on the number of vehicles is increasing the complexity of traffic in urban and highway environments. It is paramount to improve traffic management to guarantee better road usage and people’s safety. Through efficient communications, Vehicular Ad hoc Networks (VANETs) can provide enough information for traffic safety initiatives, daily traffic data processing, and entertainment information. However, VANETs are vulnerable to malicious nodes applying different types of net-work attacks, where an attacker can, for instance, forge its position to receive the data packet and drop the message. This can lead vehicles and authorities to make incorrect assumptions and decisions, which can result in dangerous situations. Therefore, any data dissemination protocol designed for VANET should consider security issues when selecting the next-hop forwarding node. In this paper, we propose a security scheme designed for position-based routing algorithms, which analyzes nodes position, transmission range, and hello packet interval. The scheme deals with malicious nodes performing network attacks, faking their positions forcing packets to be dropped. We used the Simulation of Urban MObility (SUMO) and Network Simulator-version 3 (NS-3) to compare our proposed scheme integrated with two well-known position-based algorithms. The results were collected in an urban Manhattan grid environment varying the number of nodes, the number of malicious nodes, as well as the number of source-destination pairs. The results show that the proposed security scheme can successfully improve the packet delivery ratio while maintaining low average end-to-end delay of the algorithms.

    Electric and magnetic fields effects on the excitonic properties of elliptic core-multishell quantum wires

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    The effect of eccentricity distortions of core-multishell quantum wires on their electron, hole and exciton states is theoretically investigated. Within the effective mass approximation, the Schrodinger equation is numerically solved for electrons and holes in systems with single and double radial heterostructures, and the exciton binding energy is calculated by means of a variational approach. We show that the energy spectrum of a core-multishell heterostructure with eccentricity distortions, as well as its magnetic field dependence, are very sensitive to the direction of an externally applied electric field, an effect that can be used to identify the eccentricity of the system. For a double heterostructure, the eccentricities of the inner and outer shells play an important role on the excitonic binding energy, specially in the presence of external magnetic fields, and lead to drastic modifications in the oscillator strength.Comment: 17 pages, 10 figure

    Odontological patients clustering based on art2 neural network

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    This work presents the application of Artificial Neural Networks, in particular the ART2, for the customer clustering of a dentistry room. The input data used in the application is based on the odontological anamn esis that is a form with a questionnaire applied about the professional to identify the customer case history. The three proposed customer clustering (good, medium, bad) were created with basis on the buccal hygiene care and the similar habits among the cu stomers. The network is trained using non -supervised learning that can be fast or slow learning. Each input data line is formed by the number of interviewed customers (rows) and by the answered questions (columns). However, the first step was to transform the answers into binary cells.Eje: Sistemas inteligentesRed de Universidades con Carreras en Informática (RedUNCI

    Transient electrical discharges in small devices

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    Fundamental and applied research on plasmas with high energy density that are unstable and radiate can be done at a relatively low cost with small plasma pinches. In this paper we discuss three experiments using small pinch devices: a capillary discharge, a Z-pinch driven by a small generator, and a low energy plasma focus. The experiments were complemented by magnetohydrodynamics numerical calculations in order to assist the design and physical interpretation of the experimental data. The diagnostics used in the experiments include current and voltage monitors, multipinhole camera, holographic interferometry, and vacuum ultraviolet spectroscopy.Fil: Soto, Leopoldo. Comision Chilena de Energia Nuclear; ChileFil: Esaulov, Andrey. University Of Toyama; Japón. Comision Chilena de Energia Nuclear; ChileFil: Moreno, José. Comision Chilena de Energia Nuclear; ChileFil: Silva, Patricio. Comision Chilena de Energia Nuclear; ChileFil: Sylvester, Gustavo. Comision Chilena de Energia Nuclear; ChileFil: Zambra, Marcelo. Comision Chilena de Energia Nuclear; ChileFil: Nazarenko, Andrey. Comision Chilena de Energia Nuclear; ChileFil: Clausse, Alejandro. Universidad Nacional del Centro de la Provincia de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil; Argentin
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