Search results for "UNI"
showing 10 items of 37626 documents
The uniform convergence of a double sequence of functions at a point and Korovkin-type approximation theorems
2020
Abstract In this paper, we introduce an interesting kind of convergence for a double sequence called the uniform convergence at a point. We give an example and demonstrate a Korovkin-type approximation theorem for a double sequence of functions using the uniform convergence at a point. Then we show that our result is stronger than the Korovkin theorem given by Volkov and present several graphs. Finally, in the last section, we compute the rate of convergence.
Inverse problems for $p$-Laplace type equations under monotonicity assumptions
2016
We consider inverse problems for $p$-Laplace type equations under monotonicity assumptions. In two dimensions, we show that any two conductivities satisfying $\sigma_1 \geq \sigma_2$ and having the same nonlinear Dirichlet-to-Neumann map must be identical. The proof is based on a monotonicity inequality and the unique continuation principle for $p$-Laplace type equations. In higher dimensions, where unique continuation is not known, we obtain a similar result for conductivities close to constant.
Custom measurement system for memristor characterisation
2021
Abstract A cheap, compact and customisable characterisation system for memristor devices, working between ± 10 V, is presented. SPICE (Simulation Program with Integrated Circuit Emphasis) simulations are performed to verify the circuit feasibility and a proper software is developed to drive the system. The potentiality of the realised system is tested by performing several electrical measurements on both Cu/HfO2/Pt memristors and two-terminals commercial devices.
Pulsed Electro-Acoustic Method for specimens and cables employed in HVDC systems: Some feasibility considerations
2018
Recent experiments on the use of the PEA method for testing dielectric materials in specimens and comparison with a detailed model provide an insight of the phenomenon and suggest the need of adopting similar models also for cables. What is said is even more important considering the possible future adoption of the PEA methodology to test DC cables for Pre-Qualification and Type Tests. The use of an accurate model of the PEA cell used for testing specimens and related experiments prove that the thickness of the different parts composing the PEA setup is a basic element for providing accurate charge reading and interpretation of the phenomenon. Both simulation and experimental results, carri…
Conic optical fiber probe for generation and characterization of microbubbles in liquids
2021
Abstract A novel optical fiber probe has been developed to provide mechanical stability to microbubbles generated in fluids, the tip of the fiber is etched with hydrofluoric acid to pierce a truncated horn that fastens the microbubbles to the fiber tip and prevents misalignment or detachment caused by convection currents, vibrations or shocks in the liquid. Microbubbles are photo-thermally generated on the etched fiber and used as Fabry-Perot cavity sensor. Two methods were used to interrogate the probe: the first one, in the wavelength domain, is suitable for calibration in static or quasi static situations; the second one, in the time domain, can be used in dynamic environments. Experimen…
Flexible and efficient computer-aided design tool for advanced comb-line rectangular waveguide filters
2015
A very flexible and efficient computer-aided design CAD tool, specifically suited for advanced comb-line rectangular waveguide filters, is presented in this work. The developed software tool, which makes use of a full-wave analysis technique based on the Boundary Integral-Resonant Mode Expansion method, allows loading the considered comb-line resonators with any number of radially symmetrical partial-height metallic posts. The implemented CAD tool also allows dealing with coupling windows of arbitrary cross-section, thus drastically enhancing the flexibility of the CAD process. The excitation of the analyzed components, which is performed using generalized coaxial probes, has also been inte…
Simultaneous Synthesis and Consolidation of Nanostructured MoSi2
2002
A new process combining electric field activation and the imposition of pressure from mechanically activated powder mixtures is demonstrated as a means to simultaneously synthesize and densify nano-MoSi2 in one step. Nanophase reactants (Mo + 2Si) produced by mechanical activation are reacted by field activation with the simultaneous application of a uniaxial pressure. Mo + 2Si powders were comilled in a specially designed planetary mill to obtain nanometric reactants but to avoid formation of any product phases. These were then subjected to high alternating currents (1600 A) and pressures of 106 MPa. Under these conditions, a reaction is initiated and completed within a short period of tim…
Analog isolated electronic dynamometer based on a magnetoresistive current sensor.
2017
In this work, an electronic system is presented to measure the force applied by a solenoid. The originality of the work is focused on the use of a magnetoresistive current sensor to provide the isolation barrier needed in the actual industrial plant where the solenoids are working. The design of the electronic system is presented as well as experimental measurements as a result of a calibration process showing a negligible hysteresis with that specific sensor. The magnetoresistive current sensor is used to develop transmission functions rather than playing its usual sensing roles.
Un estudio comparativo entre dos herramientas de respuesta de audiencia en las aulas universitarias
2019
El objetivo de este texto es investigar la influencia del uso de herramientas tecnológicas en las aulas universitarias. En concreto, analizamos y evaluamos la aplicación de dos herramientas de respuesta de audiencia libres (específicamente Socrative y Kahoot!) como herramientas que fomentan la participación y asistencia de los alumnos a las sesiones teóricas y facilitan el proceso de enseñanza-aprendizaje. Se analiza si estas herramientas pueden ser utilizadas como motivadoras, fomentadoras de la participación del alumnado y facilitadoras del aprendizaje. Además, la opinión de los estudiantes sobre la utilidad de estas herramientas en el aula y como métodos de enseñanza-aprendizaje. La mues…
Enabling partially reconfigurable IP cores parameterisation and integration using MARTE and IP-XACT
2012
International audience; This paper presents a framework which facilitates the parameterization and integration of IP cores into partially reconfigurable SoC platforms, departing from a high-level of abstraction. The approach is based in a Model-Driven Engineering (MDE) methodology, which exploits two widely used standards for Systems-on-Chip specification, MARTE and IP-XACT. The presented work deals with the deployment level of the MDE approach, in which the abstract components of the platform are first linked to the lower level IP-XACT counterparts. At this phase, information for parameterization and integration is readily available, and a synthesizable model can be obtained from the gener…