958 research outputs found

    Smart meter privacy via the trapdoor channel

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    A battery charging policy that provides privacy guarantees for smart meter systems with finite capacity battery is proposed. For this policy an upper bound on the information leakage rate is provided. The upper bound applies for general random processes modelling the energy consumption of the user. It is shown that the average energy consumption of the user determines the information leakage rate to the utility provider. The upper bound is shown to be tight by deriving the probability law of a random process achieving the bound

    Modelling and Configuration Control of Wing-Shaped Bi-Stable Piezoelectric Composites Under Aerodynamic Loads

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    Bi-stable composites have been considered for morphing applications thanks to their ability to hold two statically stable shapes with no energy consumption. In this paper, the modelling of the dynamic response of cantilevered wing-shaped bi-stable composites is presented. To this end, an analytical model approximating the dynamic response about each statically stable shape of wing-shaped bi-stable composites is derived. Theoretical modal properties are obtained to attain or stabilise a desired configuration following a previously introduced resonant control strategy. The resonant control technique is evaluated for a wing-shaped bi-stable composite subject to aerodynamic loads. Wind tunnel experiments are conducted on a wing-shaped specimen showing the ability of the control strategy to stabilise or attain a desired stable shape under aerodynamic loads

    El Futuro de los museos etnológicos. Consideraciones introductorias para un debate

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    Esta introducción al volumen es una reflexión sobre la situación de los museos de etnología a nivel internacional y más específicamente en el caso de España. Este libro reúne las ponencias presentadas en torno al futuro de los museos etnológicos aportando propuestas de renovación para estas instituciones tanto de contenidos como de objetivos

    Thermal behaviour of natural ester based oil used in distribution transformers

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    This work compares the thermal behavior of a distribution transformer when using as dielectric liquid a mineral oil or natural esters. These cases have been analyzed using Finite Elements Method (FEM) at the software COMSOL Multiphysics® with a 3D-symmetrical model through the Heat Transfer in Solid module. The results of simulations show a higher values of maximum temperature in mineral oil submerged transformer than in natural ester, for the same operational conditions

    Resiliencia en la escuela: promoción de factores constructores de la resiliencia dentro del ámbito educativo desde una perspectiva humanista

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    El objetivo de esta investigación fue identificar las acciones que realizan los docentes de una escuela primaria de Zapopan, Jalisco, para promover la resiliencia en los niños. Se buscó visibilizar los factores del proceso constructores de la resiliencia y la relación sobre cómo los docentes pueden promover estos pilares en la escuela a través del uso de capacidades como entrega de afecto y apoyo, transmisión de expectativas elevadas, oportunidades de participación, exploración de sus fortalezas, el desarrollo del estilo proactivo de resolución de problemas y la enseñanza del error como parte del aprendizaje

    Design a Robust Proportional-Derivative Gain-Scheduling Control for a Magnetic Levitation System

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    This study focuses on the design of a robust PD gain-scheduling controller (PD-GS-C) for an unstable SISO (single-input, single-output) magnetic levitation system with two electromagnets (MLS2EM). Magnetic levitation systems offer various advantages, including friction-free, reliable, fast, and cost-effective operations. However, due to their unstable and highly nonlinear nature, these systems require sophisticated feedback control techniques to ensure optimal performance and functionality. To address these challenges, in this study, we derive the nonlinear state-space mathematical model of the MLS2EM and linearize it around five different operating points. The PDGS-C controller aims to stabilize the system and improve steady-state control error. The strategy for obtaining the PD controller gains involves a parameter space technique, which specifies performance requirements. This technique results in ranges of proportional (KP) and derivative (KD) gains that are used by the PD-GS-C structure. To optimize the controller's performance further, we utilize the big bang-big crunch optimization technique (BB-BC) to determine the optimal PD gains within the specified ranges. The optimization process focuses on achieving optimal performance in terms of a specific performance index function. This function quantifies the system's time-domain step response criteria, which include minimizing overshoot percentage, settling time, and rising time. The index function is inversely proportional to the desired performance criteria, meaning that the goal is to maximize the index function to optimize the system's performance. To validate the effectiveness and viability of the proposed strategy, we conducts MATLAB simulations and real-time experiments. The simulations and experimental findings serve to demonstrate the controller's performance and verify its capabilities in stabilizing the MLS2EM magnetic levitation system

    Universal privacy guarantees for smart meters

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    Smart meters enable improvements in electricity distribution system efficiency at some cost in customer privacy. Users with home batteries can mitigate this privacy loss by applying charging policies that mask their underlying energy use. A battery charging policy is proposed and shown to provide universal privacy guarantees subject to a constraint on energy cost. The guarantee bounds our strategy's maximal information leakage from the user to the utility provider under general stochastic models of user energy consumption. The policy construction adapts coding strategies for non-probabilistic permuting channels to this privacy problem

    Linguistic evaluation of support verb constructions by OpenLogos and google translate

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    This paper presents a systematic human evaluation of translations of English support verb constructions produced by a rule-based machine translation (RBMT) system (OpenLogos) and a statistical machine translation (SMT) system (Google Translate) for five languages: French, German, Italian, Portuguese and Spanish. We classify support verb constructions by means of their syntactic structure and semantic behavior and present a qualitative analysis of their translation errors. The study aims to verify how machine translation (MT) systems translate fine-grained linguistic phenomena, and how well-equipped they are to produce high-quality translation. Another goal of the linguistically motivated quality analysis of SVC raw output is to reinforce the need for better system hybridization, which leverages the strengths of RBMT to the benefit of SMT, especially in improving the translation of multiword units. Taking multiword units into account, we propose an effective method to achieve MT hybridization based on the integration of semantico-syntactic knowledge into SMT.info:eu-repo/semantics/acceptedVersio

    Direct As(V) Determination Using Screen-Printed Electrodes Modified with Silver Nanoparticles

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    Carbon-nanofiber-based screen-printed electrodes modified with silver nanoparticles (Ag-NP-SPCNFEs) were tested in a pioneering manner for the direct determination of As(V) at low μg L-1 levels by means of differential pulse anodic stripping voltammetry. Screen-printed electrodes were modified with two different types of Ag-NPs, nanoseeds (NS), and nanoprisms (NPr) and characterized both microscopically and electrochemically. Furthermore, after optimizing the direct voltammetric determination of As(V), the analytical performance of considered sensors was compared for the direct determination of As(V). These results suggest that Ag-NS offer a better analytical response compared to Ag-NPr, with a detection and quantification limit of 0.6 and 1.9 µg L-1, respectively. The proposed methodology was validated using a spiked tap water sample with a very high reproducibility and good agreement with inductively coupled plasma - mass spectrometry (ICP-MS) measurements
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