Paola Girdinio - Academia.edu (original) (raw)

Papers by Paola Girdinio

2019 International Symposium on Advanced Electrical and Communication Technologies (ISAECT), 2019

Anomaly detection is an important issue heavily investigated within different research areas and ... more Anomaly detection is an important issue heavily investigated within different research areas and application domains. Its application in the industrial systems sector may be essential also for the protection of critical infrastructures. Due to the huge amount of involved data and to their complexity the use of machine learning may be the clue. The basic idea is describing an industrial process by a series of key attributes whose measures (the features) compose a state vector including heterogeneous types of measurements. Each feature should be a key attribute which can help discriminate between a normal functioning condition and an anomaly. In this context, the paper presents the use of a deep neural network architecture called autoencoder to detect anomalies due to either system faults or cyberattacks. The chosen application field is a photovoltaic system connected to the grid. The results, even if preliminary, are really promising.

International Journal for Numerical Methods in Engineering, 1999

ABSTRACT The adaptive finite element methods developed by the authors for a class of 2-D problems... more ABSTRACT The adaptive finite element methods developed by the authors for a class of 2-D problems in computational electromagnetics are presented. The cases covered are: magnetostatic, electrostatic, DC conduction and linear AC steady-state eddy currents, both plane and axialsymmetric. Theory is developed in the linear case only, but the resulting methods are applied on a heuristic basis also to non-linear cases and prove able to cope with them. These methods make use of an element-by-element error estimation and two different h-refinement techniques to adapt meshes made up of first or second-order triangular elements. Element-by- element error estimation has two main advantages: it is well suited to cope with the intricate geometries of electromagnetic devices and, at the same time, very cheap from a computational viewpoint. The local error is estimated by approximately solving a differential problem in each element. Theory on which this error estimation method is grounded is developed in full details and the underlying assumptions are pointed out. The presence in electromagnetic problems of surface currents and interfaces between different materials poses new problems in the error estimation with respect to other applications in which similar methods are used. The h-refinement technique can be selected between the bisection method and the centroid method followed by a Delaunay step. Accuracy and efficiency of the proposed method is discussed on the basis of previous work of the authors and further numerical experiments. Applications to realistic models showing good performances of the proposed methods are reported. Copyright © 1999 John wiley & Sons, Ltd.

Sensors

Distributed Energy Resources (DERs) are growing in importance Power Systems. Battery Electrical S... more Distributed Energy Resources (DERs) are growing in importance Power Systems. Battery Electrical Storage Systems (BESS) represent fundamental tools in order to balance the unpredictable power production of some Renewable Energy Sources (RES). Nevertheless, BESS are usually remotely controlled by SCADA systems, so they are prone to cyberattacks. This paper analyzes the vulnerabilities of BESS and proposes an anomaly detection algorithm that, by observing the physical behavior of the system, aims to promptly detect dangerous working conditions by exploiting the capabilities of a particular neural network architecture called the autoencoder. The results show the performance of the proposed approach with respect to the traditional One Class Support Vector Machine algorithm.

The paper describes a decision-making exploratory modelling approach to simulate different situat... more The paper describes a decision-making exploratory modelling approach to simulate different situations leading to a sustainable consumption of energy. An Agent Based Model (ABM) is proposed in order to study the individual and collective behavioural changes toward environmental sustainability using ICT-based services, the SAM4SN (Spread of Awareness Model for Social Norms) model. It explores the role of awareness in the consumption of a resource. Simulating how environmental awareness spreads is an interdisciplinary issue that involves ICT, energy and environmental science, as well as social and behavioural sciences. The agents of SAM4SN represent households whose consumption of energy has to be reduced. Agents influence each other. Such influence improves their awareness that, in turn, impacts on resource consumption. The social influence plays an important role in spreading awareness. The model includes the role of smart metering functions. The role of the sustainability tipping po...

2017 AEIT International Annual Conference, 2017

The main goal of the present paper is that of proposing a methodology for the optimal sizing of a... more The main goal of the present paper is that of proposing a methodology for the optimal sizing of a Photovoltaic (PV) unit and a Storage (ST) device, basing on data concerning typical load and PV production profiles. To achieve this result, a set of simple requirements to manage the charging/discharging of the storage is firstly proposed. Then, the overall cost of the whole system is deduced as a function of two variables (PV and ST sizes) and minimized in order to find the optimal sizing of the system. Finally, an economic analysis is presented to determine whether or not the investment is profitable.

Sensors, 2021

Critical Infrastructures (CIs) are sensible targets. They could be physically damaged by natural ... more Critical Infrastructures (CIs) are sensible targets. They could be physically damaged by natural or human actions, causing service disruptions, economic losses, and, in some extreme cases, harm to people. They, therefore, need a high level of protection against possible unintentional and intentional events. In this paper, we show a logical architecture that exploits information from both physical and cybersecurity systems to improve the overall security in a power plant scenario. We propose a Machine Learning (ML)-based anomaly detection approach to detect possible anomaly events by jointly correlating data related to both the physical and cyber domains. The performance evaluation showed encouraging results—obtained by different ML algorithms—which highlights how our proposed approach is able to detect possible abnormal situations that could not have been detected by using only information from either the physical or cyber domain.

Applied Sciences, 2021

Microgrids are growing in importance in the Smart Grid paradigm for power systems. Microgrid secu... more Microgrids are growing in importance in the Smart Grid paradigm for power systems. Microgrid security is becoming crucial since these systems increasingly rely on information and communication technologies. Many technologies have been proposed in the last few years for the protection of industrial control systems, ranging from cryptography, network security, security monitoring systems, and innovative control strategies resilient to cyber-attacks. Still, electrical systems and microgrids present their own peculiarities, and some effort has to be put forth to apply cyber-protection technologies in the electrical sector. In the present work, we discuss the latest advancements and research trends in the field of microgrid cybersecurity in a tutorial form.

Proceedings of CEM 2002 - 4th International Conference on Computation in Electromagnetics, 2002

ABSTRACT An effective method to evaluate the field coupling to a line of finite length has been p... more ABSTRACT An effective method to evaluate the field coupling to a line of finite length has been presented in this paper. It allows analyzing structures typically solved by means of the TL method even when the assumptions about the absence of the common mode current and about the TEM (or quasi-TEM) propagation mode (which implies the constraints on the line transverse dimensions with respect both to the line length and to the minimum field wavelength) are disregarded.

Journal on Policy and Complex Systems, 2017

The paper discusses the impact of social interaction on individual and collective behaviors and i... more The paper discusses the impact of social interaction on individual and collective behaviors and its effect on the consumption of energy. The underlying hypothesis is that ICT tools enable societal and psychological mechanisms leading to sustainable lifestyles. We envision tools supporting social norms, i.e. rules governing an individual\u2019s behavior by social sanctions that encourage sustainable behavior on the part of user and consumers. We present SAM4SN (Spread of Awareness Model for Social Norms), an Agent-Based Model (ABM) to explore the role of awareness in the consumption of a resource. Agents represent households that use a resource \u2013 e.g. energy or water \u2013 whose consumption has to be reduced. Agents influence each other and such influence improves their awareness that, in turn, influences resource consumption. Social influence and the role of smart metering functions as awareness's catalyst are described. SAM4SN is an exploratory model to play and explore different situations, leading or not to a sustainable consumption of energy. In particular, the sustainability tipping point and its role in decision-making will be introduced

Impresa Progetto Electronic Journal of Management, 2014

Il concetto di "Smart city", oggetto di crescente attenzione da parte dei media a livello interna... more Il concetto di "Smart city", oggetto di crescente attenzione da parte dei media a livello internazionale, sta avendo grande risonanza, come dimostrano i diversi bandi del Ministero dell'Istruzione, dell'Università e della Ricerca, anche con riferimento alle Amministrazioni Pubbliche nazionali. Le molteplici iniziative sul tema della "smartness urbana" fiorite in Italia sono inoltre indice di un incontro di competenze tecnologiche di tipo industriale, scientifico e istituzionale che rappresenta una straordinaria opportunità di sviluppo. In tale contesto la città di Genova ha intuito l'importanza di questa tematica mostrando una forte sensibilità alle iniziative europee in campo energetico e ambientale. Nel 2010, è stata infatti costituita l'Associazione Genova Smart City (AGSC), intesa come luogo di sinergie tra tutti i portatori di interesse a vario titolo coinvolti, i cui principali soggetti sono: il Comune di Genova, l'Università degli Studi di Genova, le imprese, le Organizzazioni Non Governative, le cooperative, le associazioni e le comunità di cittadini. Inoltre, per stimolare la partecipazione della cittadinanza al processo decisionale verso una città "smart", il Comune organizza periodicamente incontri periodici per raccogliere elementi sulle reali necessità della città e delle imprese del territorio. AGSC agisce, in effetti, come catalizzatore sul territorio delle competenze e delle energie esistenti nella città per caratterizzare e potenziare la sua "smartness". Al suo interno, il Comitato Scientifico si colloca in una posizione sia di indipendenza dagli specifici interessi dei singoli attori sia di servizio verso gli stessi, col fine di contrastare i possibili rischi che possono causare l'arenarsi di un progetto di simile portata.

IEEE Transactions on Electrical Insulation, 1985

A computer model of the field-enhanced motion of impurity particles has been developed by some of... more A computer model of the field-enhanced motion of impurity particles has been developed by some of the authors. It requires as input data some parameters, relevant essentially to the contact phase, in which the charge exchange between particle and electrode takes place. The parameters are to be identified experimentally, by means of various techniques, such as high-speed movies and electrical measurements of various kinds. To facilitate the parameter identification, an advanced data acquisition system, allowing an automatic analysis of film frames obtained by highspeed movies of impurity particle motion, has been devised and built. In the paper, the procedures for frame analysis are described and the data obtained are reviewed, compared with previous results, and discussed.

Digest of the Fifth Biennial IEEE Conference on Electromagnetic Field Computation

ABSTRACT Not Available

2015 IEEE 15th International Conference on Environment and Electrical Engineering (EEEIC), 2015

The present contribution proposes an adaptive two-step Energy Management System (EMS) for the opt... more The present contribution proposes an adaptive two-step Energy Management System (EMS) for the optimal operation of the Savona Campus Smart Polygeneration Microgrid (SPM). The first step aims at performing an economical optimization, as it provides the active power set-point for the programmable units that minimizes the overall production cost. The second step is related to power quality issues (power factor correction or voltage support), as it produces in output the reactive power reference signal for all the devices under converter. Moreover, due to the presence of uncertainties in the electric and thermal load request and in the Renewable Energy Sources (RES) power production, an update forecasting logic is proposed that, applied at each time step of the optimization process, refines the forecast accuracy. The experimental validation performed on the SPM shows the efficacy of the proposed EMS in satisfying both the economic and the power quality objectives.

Journal of Engineering Mathematics, 2015

The problem of the high-frequency electromagnetic field coupling with a terminated transmission l... more The problem of the high-frequency electromagnetic field coupling with a terminated transmission line is formulated and discussed in detail. Existence and uniqueness of the solution of the integro-differential equation describing the model are shown, pointing out, on the contrary, the not continuous dependence on the data. The problem is solved with three regularization methods (Landweber, Tikhonov and Truncated Singular Value Decomposition algorithms), and a comparative analysis is presented taking as reference the numerical results obtained using the Numerical Electromagnetic Code (NEC-2).

This paper addresses the issue of the analysis of t he effects of lightning flashes (direct and i... more This paper addresses the issue of the analysis of t he effects of lightning flashes (direct and indirec t) on power grid HV substations, in terms of the evaluation of overvoltage/overcurrent waveforms reaching the devices which could be potentially more afflicted by such d isturbances, namely the power transformers (or autotransformers). The study is mainly devoted to i dentify the more suitable models, methodologies and investigation tools to carry out transient evaluati ons on HV substations (1) with the final aim to def ine a calculation platform into the PSCAD-EMTDC electromagnetic environment (2) for the simulation of real p ower grid configurations. To investigate the cause of lightning failures of i nterconnection (auto)transformers, the first issue to be considered is the definition of suitable high frequ ency (HF) models for all the components of the power system under analysis (Fig. 1) and the development of tech niques for fitting the model parameters with rated character...

2011 IEEE Trondheim PowerTech, 2011

ABSTRACT The Cooray-Rubinstein (CR) formula is one of the most popular techniques used to take in... more ABSTRACT The Cooray-Rubinstein (CR) formula is one of the most popular techniques used to take into account the finite ground conductivity in the evaluation of the radial component of the lightning return stroke electric field. Nevertheless, one difficulty lies in its application: as it is expressed in the frequency domain, it can be difficult to code it in time domain simulation programs for lightning-induced overvoltages analysis. The paper shows how a suitable rational approximation of the impedance term appearing in the CR formula can lead to a simple time domain implementation of this formula. The proposed implementation offers a considerably higher computational efficiency than that of conventional methods.

Renewable and Sustainable Energy Reviews, 2009

De toenemende energievraag in de wereld, de uitputting en ongelijke verdeling van fossiele brands... more De toenemende energievraag in de wereld, de uitputting en ongelijke verdeling van fossiele brandstoffen en de gevaren van klimaatverandering vormen de drijvende kracht achter de ontwikkeling van alternatieve energiebronnen. Naar aanleiding van de in het Kyoto Protocol afgesproken doelstelling voor reductie van de uitstoot van broeikasgassen, is momenteel een verschuiving aan de gang van fossiele brandstoffen naar duurzame energiebronnen, met het doel de energievoorziening op zowel nationaal als internationaal niveau veilig te stellen.

Parallel Computing, 1989

ABSTRACT The most critical point in the implementation on a vector computer of iterative methods ... more ABSTRACT The most critical point in the implementation on a vector computer of iterative methods to solve sparse linear algebraic systems is the sparse matrix-vector product. Therefor we have compared its performance under three different sparse matrix storage schemes found in literature. These schemes have been tested on a FPS M64/330 using matrices similar to those arising in finite element or finite difference discretizations.The results are reported and discussed. On the basis of them a new storage scheme is proposed and tested in similar situations. The obtained performance is never worse and often much better than those of the other schemes we have analyzed.