Papers by Alessio Guarino
A fast fuel cell parametric identification approach based on machine learning inverse models
Energy, 2022
Games and Economic Behavior, Sep 1, 2011
We introduce a new model of aggregate information cascades where only one of two possible actions... more We introduce a new model of aggregate information cascades where only one of two possible actions is observable to others. Agents make a binary decision in sequence. The order is random and agents are not aware of their own position in the sequence. When called upon, they are only informed about the total number of others who have chosen the observable action before them. This informational structure arises naturally in many applications. Our most important result is that only one type of cascade arises in equilibrium, the aggregate cascade on the observable action. A cascade on the unobservable action never arises.
Stability Measurements in Multifilamentary Tapes
We have analyzed the behavior of a 10 cm long straight piece of copper stabilized multifilamentar... more We have analyzed the behavior of a 10 cm long straight piece of copper stabilized multifilamentary tape, manufactured by Columbus Superconductors, in a nearly adia- batic condition. The tape was biased at different current values as a function of either the temperature or the induced heat dis- turbances at fixed temperatures. From the analyses of the voltage increase, recorded from voltage taps placed at known positions, we estimated the highest temperatures which give rise to a quench of the tape at constant values of the current bias. We also measured the minimum energy triggering the quench at fixed values of current bias and temperature. The voltage taps have also been used for homogeneity check of the physical properties which rule the thermal runaway in the tape. The voltage-versus-time curves in different sections of the tape also provide information about the quench propagation speed as a function of the hot spot energy and the temperature. Due to the composite nature of the tape, made of nickel, iron, copper, and , to perform simple FEA computation we modeled the tape with a one dimensional single wire with averaged value of the physical quantities involved in the Joule heat generation and thermal conductivity.
Improving Science Teaching in Primary Schools : FoCoSTEP, a French Experience of Training Support
HAL (Le Centre pour la Communication Scientifique Directe), 2018
Development of renewable energy in Brazil: the case of Enel Green Power Ituverava Solar Park
The Brazilian macroeconomic scenario. The power sector. The clean energy sector. Photovoltaic ene... more The Brazilian macroeconomic scenario. The power sector. The clean energy sector. Photovoltaic energy. The ituverava project.
Social Science Research Network, 2020
We examine how professional traders behave in two financial market experiments; we contrast profe... more We examine how professional traders behave in two financial market experiments; we contrast professional traders' behavior to that of undergraduate students, the typical experimental subject pool. In our first experiment, both sets of participants trade an asset over multiple periods after receiving private information about its value. Second, participants play the Guessing Game. Finally, they play a novel, individual-level version of the Guessing Game and we collect data on their cognitive abilities, risk preferences, and confidence levels. We find three differences between traders and students: Traders do not generate the price bubbles observed in previous studies with student subjects; traders aggregate private information better; and traders show higher levels of strategic sophistication in the Guessing Game. Rather than reflecting differences in cognitive abilities or other individual characteristics, these results point to the impact of traders' on-the-job learning and traders' beliefs about their peers' strategic sophistication.
L’ASPEP de l’Université de la Réunion : Un Dispositif intégré au processus alternatif de professionnalisation des futurs enseignants du premier degré
HAL (Le Centre pour la Communication Scientifique Directe), Mar 1, 2017
Kaiser effect in porous materials
HAL (Le Centre pour la Communication Scientifique Directe), Oct 9, 2016
Automatic features extraction of faults in PEM fuel cells by a siamese artificial neural network
International Journal of Hydrogen Energy, Oct 1, 2021
Abstract In this paper, a procedure aimed at the automatic extraction of the features from polyme... more Abstract In this paper, a procedure aimed at the automatic extraction of the features from polymer electrolyte membrane fuel cell impedance spectra is proposed. An artificial neural network that is trained by exploiting the similarity learning concept has been used. The network learns the features of the impedance spectra and maps each of them into the embedding space by clustering them accurately and by emphasising differences among spectra corresponding to different faults. The siamese network structure is optimised and the quality of the learnt representation is evaluated by analysing the clusters obtained in the features space. The dataset of experimental spectra has been augmented in two different ways and the results are compared. The clustering quality of the proposed siamese network is compared with the one of other state of the art approaches.
IOP conference series, Dec 1, 2017
Industrial process controllers for cryogenic systems used in test facilities for superconducting ... more Industrial process controllers for cryogenic systems used in test facilities for superconducting magnets are typically PIDs, tuned by operational expertise according to users' requirements (covering cryogenic transients and associated thermo-mechanical constraints). In this paper, an alternative fully-automatic solution, equally based on PID controllers, is proposed. Following the comparison of the operational expertise and alternative fully-automatic approaches, a new process control configuration, based on an estimated multiple-input/multipleoutput (MIMO) model is proposed. The new MIMO model-based approach fulfils the required operational constraints while improving performance compared to existing solutions. The analysis and design work is carried out using both theoretical and numerical tools and is validated on the case study of the High Field Magnet (HFM) cryogenic test bench running at the SM18 test facility located at CERN. The proposed solution have been validated by simulation using the CERN ECOSIMPRO software tools using the cryogenic library (CRYOLIB [1]) developed at CERN.
A battery residual capacity indicator based on the battery internal resistance: an experimental study
Capacity fade of lithium-ion rechargeable battery is a slow process, driven by the passing time (... more Capacity fade of lithium-ion rechargeable battery is a slow process, driven by the passing time (calendar aging) and by the battery operating conditions (cycling aging). The operating conditions exhibit very fast dynamics (e.g., the battery current of an electric vehicle) as well as moderately slow ones (e.g., the ambient temperature variation). Because of the huge time-scale differences between the capacity fade phenomenon and the battery usage waveforms, it is very difficult to compact the waveform information and to predict the actual capacity. It is therefore necessary to extract a minimal set of indicators that are useful for the capacity estimation. For this reason, we analyse the possibility of using the battery internal resistance as a predictor for the estimation of the residual capacity. The analysis is carried out for Lithium Cobalt batteries continuously operated with random current patterns and in pulsed current tests, where the influence of the state of charge can be neglected. The results show that a linear correlation between the internal resistance and the capacity can be established, so that it is possible to use the resistance to assess the residual capacity.
Mathematics and Computers in Simulation, Jun 1, 2021
SoC-based embedded real-time simulation of mismatched photovoltaic strings, Mathematics and Compu... more SoC-based embedded real-time simulation of mismatched photovoltaic strings, Mathematics and Computers in Simulation (2020),
HAL (Le Centre pour la Communication Scientifique Directe), Apr 30, 2019
Energies, Sep 2, 2019
In this paper, the Dual Kalman Filter (DKF) is used for the parametric identification of an RC mo... more In this paper, the Dual Kalman Filter (DKF) is used for the parametric identification of an RC model of a Polymer Electrolyte Membrane Fuel Cell (FC) stack. The identification is performed for diagnostic purposes, starting from time-domain voltage and current signals in the framework of Electrochemical Impedance Spectroscopy (EIS) tests. Here, the sinusoidal input of the tests makes the identification of DKF parameters challenging. The paper analyzes the filter performance and proposes a possible approach to address the filter tuning to let it work with FC operating either in normal conditions or in the presence of drying and flooding fault conditions, or in fuel starvation mode. The analysis is mainly performed in a simulated environment, where the Fouquet model is used to simulate the FC. Some criteria to tune the filter are derived from the analysis and used also with experimental data produced by some EIS tests, to achieve the best estimate in constrained conditions. The results show that the DKF can be turned into a valuable tool to identify the model parameters even with signals developed for other scopes. The identification results envisage the possibility of assisting the model-based FC diagnosis by means of a very simple tool that can run on a low-cost embedded device. Indeed, the simplicity of the filter approach and a lightweight implementation allow the deployment of the algorithm in embedded solutions.
RePEc: Research Papers in Economics, 2010
We study a sequential trading financial market where there are gains from trade, that is, where i... more We study a sequential trading financial market where there are gains from trade, that is, where informed traders have heterogeneous private values. We show that an informational cascade (i.e., a complete blockage of information) arises and prices fail to aggregate information dispersed among traders. During an informational cascade, all traders with the same preferences choose the same action, following the market (herding) or going against it (contrarianism). We also study financial contagion by extending our model to a two-asset economy. We show that informational cascades in one market can be generated by informational spillovers from the other. Such spillovers have pathological consequences, generating long-lasting misalignments between prices and fundamentals.
Social Science Research Network, 2015
We study the informational channel of Önancial contagion in the laboratory. In our experiment, tw... more We study the informational channel of Önancial contagion in the laboratory. In our experiment, two markets with privately informed subjects open sequentially. Subjects in the second market observe the history of trades and prices in the Örst market. Although in both markets private information is imperfectly aggregated, subjects in the second market make correct inferences from the information coming from the Örst market. As theory predicts, when fundamentals are correlated, contagion occurs in the laboratory; in contrast, with independent fundamentals, there is no contagion e §ect. In both cases, the correlation between asset prices is very close to the theoretical one.
Pemfc Fault Classification Based on Noisy and Noiseless Eis Impedance Spectra
Social Science Research Network, 2022
CHROMATOGRAPHIC SEPARATION AND RADIOMETRIC ANALYSIS OF C$sup 14$-LABELLED SUBSTANCES HAVING A HIGH BOILING POINT
A technique for the simultaneous chromotographic and radiometric analysis of substances containin... more A technique for the simultaneous chromotographic and radiometric analysis of substances containing radiocarbon and having a high boiling point is described. This method is based on the continuous combustion of radioactive compounds flowing from the column together with water and CO/sup 2/, the latter then comes to the thermoconductive cell of the chromatograph and to a flux ionization chamber. Measurement is made of the concentration and activity of separated compounds. (auth)
A Comparison of Ensemble Machine Learning Techniques for the Estimate of Residual Capacity of Li-Ion Batteries
State of Health is a generalised indicator to establish the ageing conditions of a battery and it... more State of Health is a generalised indicator to establish the ageing conditions of a battery and it is usually calculated by starting from the remaining capacity. Unfortunately, under normal operating conditions, the residual capacity is not measurable, and therefore it is necessary to estimate it. Various techniques have been employed to perform the estimation, both from the model-based and the data-driven domains, with results that are strongly dependent on the underlying model accuracy or on the quality and on the processing of the input predictor vector. In this paper, the capacity estimation problem is tackled by employing ensemble learning techniques with data obtained under operating conditions that are deliberately challenging to perform a data-driven estimate. A comparison framework was settled and the performance of two ensemble learning techniques, called bagging and boosting, were investigated when trained with two different predictor vectors. Analysing and crossing the obtained results, it is possible to show that, while both techniques seem to be insensitive to some peculiar predictor vectors, bagging provides a lower estimation error than the boosting technique.
A hydrodynamics model to help prevent hypoxia of the fauna and flora in Polynesian’s Bays
HAL (Le Centre pour la Communication Scientifique Directe), 2018
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Papers by Alessio Guarino