152 results on '"PERNICE, Riccardo"'
Search Results
2. Local and global measures of information storage for the assessment of heartbeat-evoked cortical responses
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Barà, Chiara, Zaccaro, Andrea, Antonacci, Yuri, Dalla Riva, Matteo, Busacca, Alessandro, Ferri, Francesca, Faes, Luca, and Pernice, Riccardo
- Published
- 2023
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3. Photoplethysmograhic sensors, potential and limitations: Is it time for regulation? A comprehensive review
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Scardulla, Francesco, Cosoli, Gloria, Spinsante, Susanna, Poli, Angelica, Iadarola, Grazia, Pernice, Riccardo, Busacca, Alessandro, Pasta, Salvatore, Scalise, Lorenzo, and D'Acquisto, Leonardo
- Published
- 2023
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4. Adaptive scheduling of acceleration and gyroscope for motion artifact cancelation in photoplethysmography
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Lee, Hooseok, Chung, Heewon, Ko, Hoon, Parisi, Antonino, Busacca, Alessandro, Faes, Luca, Pernice, Riccardo, and Lee, Jinseok
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- 2022
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5. Comparison of frequency domain measures based on spectral decomposition for spontaneous baroreflex sensitivity assessment after Acute Myocardial Infarction
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Pernice, Riccardo, Sparacino, Laura, Nollo, Giandomenico, Stivala, Salvatore, Busacca, Alessandro, and Faes, Luca
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- 2021
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6. Testing dynamic correlations and nonlinearity in bivariate time series through information measures and surrogate data analysis.
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Pinto, Helder, Lazic, Ivan, Antonacci, Yuri, Pernice, Riccardo, Danlei Gu, Barà, Chiara, Faes, Luca, and Ana Paula Rocha
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INFORMATION retrieval ,STOCHASTIC systems ,BIVARIATE analysis ,RESPIRATION ,HYPOTHESIS - Abstract
The increasing availability of time series data depicting the evolution of physical system properties has prompted the development of methods focused on extracting insights into the system behavior over time, discerning whether it stems from deterministic or stochastic dynamical systems. Surrogate data testing plays a crucial role in this process by facilitating robust statistical assessments. This ensures that the observed results are not mere occurrences by chance, but genuinely reflect the inherent characteristics of the underlying system. The initial process involves formulating a null hypothesis, which is tested using surrogate data in cases where assumptions about the underlying distributions are absent. A discriminating statistic is then computed for both the original data and each surrogate data set. Significantly deviating values between the original data and the surrogate data ensemble lead to the rejection of the null hypothesis. In this work, we present various surrogate methods designed to assess specific statistical properties in random processes. Specifically, we introduce methods for evaluating the presence of auto-dependencies and nonlinear dynamics within individual processes, using Information Storage as a discriminating statistic. Additionally, methods are introduced for detecting coupling and nonlinearities in bivariate processes, employing the Mutual Information Rate for this purpose. The surrogate methods introduced are first tested through simulations involving univariate and bivariate processes exhibiting both linear and nonlinear dynamics. Then, they are applied to physiological time series of Heart Period (RR intervals) and respiratory flow (RESP) variability measured during spontaneous and paced breathing. Simulations demonstrated that the proposed methods effectively identify essential dynamical features of stochastic systems. The real data application showed that paced breathing, at low breathing rate, increases the predictability of the individual dynamics of RR and RESP and dampens nonlinearity in their coupled dynamics. [ABSTRACT FROM AUTHOR]
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- 2024
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7. Wearable Ring-Shaped Biomedical Device for Physiological Monitoring through Finger-Based Acquisition of Electrocardiographic, Photoplethysmographic, and Galvanic Skin Response Signals: Design and Preliminary Measurements.
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Volpes, Gabriele, Valenti, Simone, Genova, Giuseppe, Barà, Chiara, Parisi, Antonino, Faes, Luca, Busacca, Alessandro, and Pernice, Riccardo
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GALVANIC skin response ,PATIENT monitoring ,PHYSIOLOGICAL stress ,PSYCHOLOGICAL stress ,OXYGEN saturation - Abstract
Wearable health devices (WHDs) are rapidly gaining ground in the biomedical field due to their ability to monitor the individual physiological state in everyday life scenarios, while providing a comfortable wear experience. This study introduces a novel wearable biomedical device capable of synchronously acquiring electrocardiographic (ECG), photoplethysmographic (PPG), galvanic skin response (GSR) and motion signals. The device has been specifically designed to be worn on a finger, enabling the acquisition of all biosignals directly on the fingertips, offering the significant advantage of being very comfortable and easy to be employed by the users. The simultaneous acquisition of different biosignals allows the extraction of important physiological indices, such as heart rate (HR) and its variability (HRV), pulse arrival time (PAT), GSR level, blood oxygenation level (SpO
2 ), and respiratory rate, as well as motion detection, enabling the assessment of physiological states, together with the detection of potential physical and mental stress conditions. Preliminary measurements have been conducted on healthy subjects using a measurement protocol consisting of resting states (i.e., SUPINE and SIT) alternated with physiological stress conditions (i.e., STAND and WALK). Statistical analyses have been carried out among the distributions of the physiological indices extracted in time, frequency, and information domains, evaluated under different physiological conditions. The results of our analyses demonstrate the capability of the device to detect changes between rest and stress conditions, thereby encouraging its use for assessing individuals' physiological state. Furthermore, the possibility of performing synchronous acquisitions of PPG and ECG signals has allowed us to compare HRV and pulse rate variability (PRV) indices, so as to corroborate the reliability of PRV analysis under stationary physical conditions. Finally, the study confirms the already known limitations of wearable devices during physical activities, suggesting the use of algorithms for motion artifact correction. [ABSTRACT FROM AUTHOR]- Published
- 2024
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8. One diode circuital model of light soaking phenomena in Dye-Sensitized Solar Cells
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Laudani, Antonino, Riganti Fulginei, Francesco, Salvini, Alessandro, Parisi, Antonino, Pernice, Riccardo, Ricco Galluzzo, Fabio, Cino, Alfonso C., and Busacca, Alessandro C.
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- 2018
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9. Electro-optical characterization of ruthenium-based dye sensitized solar cells: A study of light soaking, ageing and temperature effects
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Parisi, Antonino, Pernice, Riccardo, Andò, Andrea, Cino, Alfonso C., Franzitta, Vincenzo, and Busacca, Alessandro C.
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- 2017
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10. Information-Theoretic Analysis of Cardio-Respiratory Interactions in Heart Failure Patients: Effects of Arrhythmias and Cardiac Resynchronization Therapy.
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Platiša, Mirjana M., Radovanović, Nikola N., Pernice, Riccardo, Barà, Chiara, Pavlović, Siniša U., and Faes, Luca
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CARDIAC pacing ,HEART failure patients ,ARRHYTHMIA ,PATIENT selection ,SINUS arrhythmia ,INFORMATION theory - Abstract
The properties of cardio-respiratory coupling (CRC) are affected by various pathological conditions related to the cardiovascular and/or respiratory systems. In heart failure, one of the most common cardiac pathological conditions, the degree of CRC changes primarily depend on the type of heart-rhythm alterations. In this work, we investigated CRC in heart-failure patients, applying measures from information theory, i.e., Granger Causality (GC), Transfer Entropy (TE) and Cross Entropy (CE), to quantify the directed coupling and causality between cardiac (RR interval) and respiratory (Resp) time series. Patients were divided into three groups depending on their heart rhythm (sinus rhythm and presence of low/high number of ventricular extrasystoles) and were studied also after cardiac resynchronization therapy (CRT), distinguishing responders and non-responders to the therapy. The information-theoretic analysis of bidirectional cardio-respiratory interactions in HF patients revealed the strong effect of nonlinear components in the RR (high number of ventricular extrasystoles) and in the Resp time series (respiratory sinus arrhythmia) as well as in their causal interactions. We showed that GC as a linear model measure is not sensitive to both nonlinear components and only model free measures as TE and CE may quantify them. CRT responders mainly exhibit unchanged asymmetry in the TE values, with statistically significant dominance of the information flow from Resp to RR over the opposite flow from RR to Resp, before and after CRT. In non-responders this asymmetry was statistically significant only after CRT. Our results indicate that the success of CRT is related to corresponding information transfer between the cardiac and respiratory signal quantified at baseline measurements, which could contribute to a better selection of patients for this type of therapy. [ABSTRACT FROM AUTHOR]
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- 2023
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11. Abundance variations within feeding guilds reveal ecological mechanisms behind avian species richness pattern along the elevational gradient of Mount Cameroon.
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Sedláček, Ondřej, Pernice, Riccardo, Ferenc, Michal, Mudrová, Karolína, Motombi, Francis Njie, Albrecht, Tomáš, and Hořák, David
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SPECIES diversity ,ECOLOGICAL carrying capacity ,NUMBERS of species ,GUILDS ,ALTITUDES - Abstract
Two distinct diversity patterns are observed along tropical elevations: (a) decreasing number of species toward high elevations and (b) a hump‐shaped pattern with the peak at mid‐elevations. As diversity is likely supported by ecological capacity of the environment, decomposition of the overall richness into ecological facets and considering number of individuals within them is crucial for the proper understanding of richness patterns. We examined abundances of different avian guilds along the forested part of the elevational gradient on Mt. Cameroon. We (a) compared richness and abundance elevational patterns, (b) assessed the effective contribution of multiple guilds to richness and abundance patterns, and (c) assessed to what extent observed abundances of guilds differed from those expected by chance. We sampled birds in 2011–2015 during the dry season at seven elevations (30 m, 350 m, 650 m, 1100 m, 1500 m, 1850 m, 2200 m a.s.l.). For each assemblage, we estimated proportions of species and individuals that use particular diets, foraging modes, and feeding strata. We found that a rather decreasing pattern of species richness turns into a hump‐shaped one if we look at the total abundances, implying different mechanisms behind these patterns. The number of species and individuals thus do not seem to be directly related, contrary to "the more‐individuals hypothesis." Abundances of foliage gleaners at mid‐elevations, nectarivores at high elevations, and frugivores at low elevations deviated from random expectations. Our results imply that parts of ecological space are filled separately by bird species and individuals along elevation of Mt. Cameroon. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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12. Wearable Multisensor Ring-Shaped Probe for Assessing Stress and Blood Oxygenation: Design and Preliminary Measurements.
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Valenti, Simone, Volpes, Gabriele, Parisi, Antonino, Peri, Daniele, Lee, Jinseok, Faes, Luca, Busacca, Alessandro, and Pernice, Riccardo
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GALVANIC skin response ,OXYGEN in the blood ,BREATH holding ,OXYGEN saturation ,PHOTOPLETHYSMOGRAPHY ,PATIENT monitoring - Abstract
The increasing interest in innovative solutions for health and physiological monitoring has recently fostered the development of smaller biomedical devices. These devices are capable of recording an increasingly large number of biosignals simultaneously, while maximizing the user's comfort. In this study, we have designed and realized a novel wearable multisensor ring-shaped probe that enables synchronous, real-time acquisition of photoplethysmographic (PPG) and galvanic skin response (GSR) signals. The device integrates both the PPG and GSR sensors onto a single probe that can be easily placed on the finger, thereby minimizing the device footprint and overall size. The system enables the extraction of various physiological indices, including heart rate (HR) and its variability, oxygen saturation (SpO
2 ), and GSR levels, as well as their dynamic changes over time, to facilitate the detection of different physiological states, e.g., rest and stress. After a preliminary SpO2 calibration procedure, measurements have been carried out in laboratory on healthy subjects to demonstrate the feasibility of using our system to detect rapid changes in HR, skin conductance, and SpO2 across various physiological conditions (i.e., rest, sudden stress-like situation and breath holding). The early findings encourage the use of the device in daily-life conditions for real-time monitoring of different physiological states. [ABSTRACT FROM AUTHOR]- Published
- 2023
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13. Comparison of discretization strategies for the model-free information-theoretic assessment of short-term physiological interactions.
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Barà, Chiara, Sparacino, Laura, Pernice, Riccardo, Antonacci, Yuri, Porta, Alberto, Kugiumtzis, Dimitris, and Faes, Luca
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RESPIRATION ,CEREBRAL circulation ,SYSTOLIC blood pressure ,STOCHASTIC processes ,RANDOM variables ,FLOW velocity ,TIME series analysis - Abstract
This work presents a comparison between different approaches for the model-free estimation of information-theoretic measures of the dynamic coupling between short realizations of random processes. The measures considered are the mutual information rate (MIR) between two random processes X and Y and the terms of its decomposition evidencing either the individual entropy rates of X and Y and their joint entropy rate, or the transfer entropies from X to Y and from Y to X and the instantaneous information shared by X and Y. All measures are estimated through discretization of the random variables forming the processes, performed either via uniform quantization (binning approach) or rank ordering (permutation approach). The binning and permutation approaches are compared on simulations of two coupled non-identical Hènon systems and on three datasets, including short realizations of cardiorespiratory (CR, heart period and respiration flow), cardiovascular (CV, heart period and systolic arterial pressure), and cerebrovascular (CB, mean arterial pressure and cerebral blood flow velocity) measured in different physiological conditions, i.e., spontaneous vs paced breathing or supine vs upright positions. Our results show that, with careful selection of the estimation parameters (i.e., the embedding dimension and the number of quantization levels for the binning approach), meaningful patterns of the MIR and of its components can be achieved in the analyzed systems. On physiological time series, we found that paced breathing at slow breathing rates induces less complex and more coupled CR dynamics, while postural stress leads to unbalancing of CV interactions with prevalent baroreflex coupling and to less complex pressure dynamics with preserved CB interactions. These results are better highlighted by the permutation approach, thanks to its more parsimonious representation of the discretized dynamic patterns, which allows one to explore interactions with longer memory while limiting the curse of dimensionality. [ABSTRACT FROM AUTHOR]
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- 2023
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14. Assessing Transfer Entropy in cardiovascular and respiratory time series: A VARFI approach
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Rocha, Ana Paula, Pinto, Helder, Amado, Celestino, Silva, Maria Eduarda, Pernice, Riccardo, Javorka, Michal, Faes, Luca, Rocha, Ana Paula, Pinto, Helder, Amado, Celestino, Silva, Maria Eduarda, Pernice, Riccardo, Javorka, Michal, and Faes, Luca
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vector autoregressive fractionally integrated (VARFI) model ,Settore ING-INF/06 - Bioingegneria Elettronica E Informatica ,systolic arterial pressure (SAP) ,Multi-scale entropy (MSE) ,heart rate variability (HRV) - Abstract
In the study of complex biomedical systems represented by multivariate stochastic processes, such as the cardiovascular and respiratory systems, an issue of great relevance is the description of the system dynamics spanning multiple temporal scales. Recently, the quantification of multiscale complexity based on linear parametric models, incorporating autoregressive coefficients and fractional integration, encompassing short term dynamics and long-range correlations, was extended to multivariate time series. Within this Vector AutoRegressive Fractionally Integrated (VARFI) framework formalized for Gaussian processes, in this work we propose to estimate the Transfer Entropy, or equivalently Granger Causality, in the cardiovascular and respiratory systems. This allows to quantify the information flow and assess directed interactions accounting for the simultaneous presence of short-term dynamics and long-range correlations. The proposed approach is first tested on simulations of benchmark VARFI processes where the transfer entropy could be computed from the known model parameters. Then, it is applied to experimental data consisting of heart period, systolic arterial pressure and respiration time series measured in healthy subjects monitored at rest and during mental and postural stress. Both simulations and real data analysis revealed that the proposed method highlights the dependence of the information transfer on the balance between short-term and longrange correlations in coupled dynamical systems.
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- 2021
15. Feasibility of Ultra-Short-Term Analysis of Heart Rate and Systolic Arterial Pressure Variability at Rest and during Stress via Time-Domain and Entropy-Based Measures.
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Volpes, Gabriele, Barà, Chiara, Busacca, Alessandro, Stivala, Salvatore, Javorka, Michal, Faes, Luca, and Pernice, Riccardo
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SYSTOLIC blood pressure ,BLOOD pressure ,TIME series analysis ,TIME pressure ,HEART beat - Abstract
Heart Rate Variability (HRV) and Blood Pressure Variability (BPV) are widely employed tools for characterizing the complex behavior of cardiovascular dynamics. Usually, HRV and BPV analyses are carried out through short-term (ST) measurements, which exploit ~five-minute-long recordings. Recent research efforts are focused on reducing the time series length, assessing whether and to what extent Ultra-Short-Term (UST) analysis is capable of extracting information about cardiovascular variability from very short recordings. In this work, we compare ST and UST measures computed on electrocardiographic R-R intervals and systolic arterial pressure time series obtained at rest and during both postural and mental stress. Standard time–domain indices are computed, together with entropy-based measures able to assess the regularity and complexity of cardiovascular dynamics, on time series lasting down to 60 samples, employing either a faster linear parametric estimator or a more reliable but time-consuming model-free method based on nearest neighbor estimates. Our results are evidence that shorter time series down to 120 samples still exhibit an acceptable agreement with the ST reference and can also be exploited to discriminate between stress and rest. Moreover, despite neglecting nonlinearities inherent to short-term cardiovascular dynamics, the faster linear estimator is still capable of detecting differences among the conditions, thus resulting in its suitability to be implemented on wearable devices. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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16. Multiscale partial information decomposition of dynamic processes with short and long-range correlations: theory and application to cardiovascular control.
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Pinto, Hélder, Pernice, Riccardo, Eduarda Silva, Maria, Javorka, Michal, Faes, Luca, and Rocha, Ana Paula
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TIME series analysis , *GAUSSIAN processes , *PSYCHOLOGICAL stress , *SYSTOLIC blood pressure , *CARDIOVASCULAR system , *RESPIRATORY organs - Abstract
Objective. In this work, an analytical framework for the multiscale analysis of multivariate Gaussian processes is presented, whereby the computation of Partial Information Decomposition measures is achieved accounting for the simultaneous presence of short-term dynamics and long-range correlations. Approach. We consider physiological time series mapping the activity of the cardiac, vascular and respiratory systems in the field of Network Physiology. In this context, the multiscale representation of transfer entropy within the network of interactions among Systolic arterial pressure (S), respiration (R) and heart period (H), as well as the decomposition into unique, redundant and synergistic contributions, is obtained using a Vector AutoRegressive Fractionally Integrated (VARFI) framework for Gaussian processes. This novel approach allows to quantify the directed information flow accounting for the simultaneous presence of short-term dynamics and long-range correlations among the analyzed processes. Additionally, it provides analytical expressions for the computation of the information measures, by exploiting the theory of state space models. The approach is first illustrated in simulated VARFI processes and then applied to H, S and R time series measured in healthy subjects monitored at rest and during mental and postural stress. Main Results. We demonstrate the ability of the VARFI modeling approach to account for the coexistence of short-term and long-range correlations in the study of multivariate processes. Physiologically, we show that postural stress induces larger redundant and synergistic effects from S and R to H at short time scales, while mental stress induces larger information transfer from S to H at longer time scales, thus evidencing the different nature of the two stressors. Significance. The proposed methodology allows to extract useful information about the dependence of the information transfer on the balance between short-term and long-range correlations in coupled dynamical systems, which cannot be observed using standard methods that do not consider long-range correlations. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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17. Pairwise and higher-order measures of brain-heart interactions in children with temporal lobe epilepsy.
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Pernice, Riccardo, Faes, Luca, Feucht, Martha, Benninger, Franz, Mangione, Stefano, and Schiecke, Karin
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- 2022
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18. Information decomposition in the frequency domain: a new framework to study cardiovascular and cardiorespiratory oscillations.
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Faes, Luca, Pernice, Riccardo, Mijatovic, Gorana, Antonacci, Yuri, Cernanova Krohova, Jana, Javorka, Michal, and Porta, Alberto
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TIME series analysis , *OSCILLATIONS , *MULTIVARIATE analysis , *SUPINE position , *PREDICATE calculus , *HEART beat , *STOCHASTIC processes , *FLUCTUATIONS (Physics) - Abstract
While cross-spectral and information-theoretic approaches are widely used for the multivariate analysis of physiological time series, their combined utilization is far less developed in the literature. This study introduces a framework for the spectral decomposition of multivariate information measures, which provides frequencyspecific quantifications of the information shared between a target and two source time series and of its expansion into amounts related to how the sources contribute to the target dynamics with unique, redundant and synergistic information. The framework is illustrated in simulations of linearly interacting stochastic processes, showing how it allows us to retrieve amounts of information shared by the processes within specific frequency bands which are otherwise not detectable by time-domain information measures, as well as coupling features which are not detectable by spectral measures. Then, it is applied to the time series of heart period, systolic and diastolic arterial pressure and respiration variability measured in healthy subjects monitored in the resting supine position and during head-up tilt. We show that the spectral measures of unique, redundant and synergistic information shared by these variability series, integrated within specific frequency bands of physiological interest and reflect the mechanisms of short-term regulation of cardiovascular and cardiorespiratory oscillations and their alterations induced by the postural stress. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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19. Multivariate Correlation Measures Reveal Structure and Strength of Brain–Body Physiological Networks at Rest and During Mental Stress.
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Pernice, Riccardo, Antonacci, Yuri, Zanetti, Matteo, Busacca, Alessandro, Marinazzo, Daniele, Faes, Luca, and Nollo, Giandomenico
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PSYCHOLOGICAL stress ,HUMAN body ,BLOOD volume ,TIME series analysis ,HEART beat - Abstract
In this work, we extend to the multivariate case the classical correlation analysis used in the field of network physiology to probe dynamic interactions between organ systems in the human body. To this end, we define different correlation-based measures of the multivariate interaction (MI) within and between the brain and body subnetworks of the human physiological network, represented, respectively, by the time series of δ, θ, α, and β electroencephalographic (EEG) wave amplitudes, and of heart rate, respiration amplitude, and pulse arrival time (PAT) variability (η, ρ, π). MI is computed: (i) considering all variables in the two subnetworks to evaluate overall brain–body interactions; (ii) focusing on a single target variable and dissecting its global interaction with all other variables into contributions arising from the same subnetwork and from the other subnetwork; and (iii) considering two variables conditioned to all the others to infer the network topology. The framework is applied to the time series measured from the EEG, electrocardiographic (ECG), respiration, and blood volume pulse (BVP) signals recorded synchronously via wearable sensors in a group of healthy subjects monitored at rest and during mental arithmetic and sustained attention tasks. We find that the human physiological network is highly connected, with predominance of the links internal of each subnetwork (mainly η−ρ and δ−θ, θ−α, α−β), but also statistically significant interactions between the two subnetworks (mainly η−β and η−δ). MI values are often spatially heterogeneous across the scalp and are modulated by the physiological state, as indicated by the decrease of cardiorespiratory interactions during sustained attention and by the increase of brain–heart interactions and of brain–brain interactions at the frontal scalp regions during mental arithmetic. These findings illustrate the complex and multi-faceted structure of interactions manifested within and between different physiological systems and subsystems across different levels of mental stress. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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20. Respiratory Sinus Arrhythmia Mechanisms in Young Obese Subjects.
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Javorka, Michal, Krohova, Jana, Czippelova, Barbora, Turianikova, Zuzana, Mazgutova, Nikoleta, Wiszt, Radovan, Ciljakova, Miriam, Cernochova, Dana, Pernice, Riccardo, Busacca, Alessandro, and Faes, Luca
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SINUS arrhythmia ,HEART beat ,AUTONOMIC nervous system ,SYSTOLIC blood pressure ,KNOWLEDGE transfer - Abstract
Autonomic nervous system (ANS) activity and imbalance between its sympathetic and parasympathetic components are important factors contributing to the initiation and progression of many cardiovascular disorders related to obesity. The results on respiratory sinus arrhythmia (RSA) magnitude changes as a parasympathetic index were not straightforward in previous studies on young obese subjects. Considering the potentially unbalanced ANS regulation with impaired parasympathetic control in obese patients, the aim of this study was to compare the relative contribution of baroreflex and non-baroreflex (central) mechanisms to the origin of RSA in obese vs. control subjects. To this end, we applied a recently proposed information-theoretic methodology – partial information decomposition (PID) – to the time series of heart rate variability (HRV, computed from RR intervals in the ECG), systolic blood pressure (SBP) variability, and respiration (RESP) pattern measured in 29 obese and 29 age- and gender-matched non-obese adolescents and young adults monitored in the resting supine position and during postural and cognitive stress evoked by head-up tilt and mental arithmetic. PID was used to quantify the so-called unique information transferred from RESP to HRV and from SBP to HRV, reflecting, respectively, non-baroreflex and RESP-unrelated baroreflex HRV mechanisms, and the redundant information transferred from (RESP, SBP) to HRV, reflecting RESP-related baroreflex RSA mechanisms. Our results suggest that obesity is associated: (i) with blunted involvement of non-baroreflex RSA mechanisms, documented by the lower unique information transferred from RESP to HRV at rest; and (ii) with a reduced response to postural stress (but not to mental stress), documented by the lack of changes in the unique information transferred from RESP and SBP to HRV in obese subjects moving from supine to upright, and by a decreased redundant information transfer in obese compared to controls in the upright position. These findings were observed in the presence of an unchanged RSA magnitude measured as the high frequency (HF) power of HRV, thus suggesting that the changes in ANS imbalance related to obesity in adolescents and young adults are subtle and can be revealed by dissecting RSA mechanisms into its components during various challenges. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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21. Comparison of methods for the assessment of nonlinearity in short-term heart rate variability under different physiopathological states.
- Author
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Faes, Luca, Gómez-Extremera, Manuel, Pernice, Riccardo, Carpena, Pedro, Nollo, Giandomenico, Porta, Alberto, and Bernaola-Galván, Pedro
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HEART beat ,SUPINE position ,ALPHA rhythm ,INFORMATION retrieval ,MYOCARDIAL infarction - Abstract
Despite the widespread diffusion of nonlinear methods for heart rate variability (HRV) analysis, the presence and the extent to which nonlinear dynamics contribute to short-term HRV are still controversial. This work aims at testing the hypothesis that different types of nonlinearity can be observed in HRV depending on the method adopted and on the physiopathological state. Two entropy-based measures of time series complexity (normalized complexity index, NCI) and regularity (information storage, IS), and a measure quantifying deviations from linear correlations in a time series (Gaussian linear contrast, GLC), are applied to short HRV recordings obtained in young (Y) and old (O) healthy subjects and in myocardial infarction (MI) patients monitored in the resting supine position and in the upright position reached through head-up tilt. The method of surrogate data is employed to detect the presence and quantify the contribution of nonlinear dynamics to HRV. We find that the three measures differ both in their variations across groups and conditions and in the percentage and strength of nonlinear HRV dynamics. NCI and IS displayed opposite variations, suggesting more complex dynamics in O and MI compared to Y and less complex dynamics during tilt. The strength of nonlinear dynamics is reduced by tilt using all measures in Y, while only GLC detects a significant strengthening of such dynamics in MI. A large percentage of detected nonlinear dynamics is revealed only by the IS measure in the Y group at rest, with a decrease in O and MI and during T, while NCI and GLC detect lower percentages in all groups and conditions. While these results suggest that distinct dynamic structures may lie beneath short-term HRV in different physiological states and pathological conditions, the strong dependence on the measure adopted and on their implementation suggests that physiological interpretations should be provided with caution. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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22. Non-uniform doping concentration CIGS absorber profile for highefficiency solar cells
- Author
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PERNICE, Riccardo, PARISI, Antonino, ADAMO, Gabriele, CARDONA, Fabio, CINO, Alfonso Carmelo, Crupi, Isodiana, BUSACCA, Alessandro, Pernice, R, Parisi, A, Adamo, G, Cardona, F, Cino, AC, Crupi, I, and Busacca, A
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Settore ING-INF/02 - Campi Elettromagnetici ,CIGS, simulations, solar cell, photovoltaics ,Settore ING-INF/01 - Elettronica - Abstract
The quaternary chalcopyrite semiconductor alloy Cu(In,Ga)Se2 (CIGS) is nowadays commonly considered one of the most suitable materials to fabricate cost-effective and high-efficiency photovoltaic cells. Thanks to the optical and structural properties of the absorber layer and to the tunable bandgap, thin-film CIGS cells have reached efficiencies around 20%, not far from the maximum values of traditional crystalline silicon cells. This high efficiency, together with the conceivable low fabrication costs, makes CIGS cells a promising alternative to silicon technology for large-scale production. In order to further improve the cells performance, in a previous work we have already proposed a simple structure having a linear graded carrier concentration absorber profile, which allows to induce a quasi-electrical field directed towards the back-contact, like CIGS cells with a Ga back-graded profile. Thanks to the increase of Ec and Ev towards the backcontact, while keeping the energy gap constant along the depth, the generation process is even more efficient in our structure, thus improving cells performance (efficiency over 21%). Herein, we investigate on other non-uniform doping concentration profiles that can be technologically easily realised, still maintaining the already demonstrated high-efficiency values.
- Published
- 2016
23. Radiofrequency performances of different Graphene Field Effect Transistors geometries
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Giambra, Marco Angelo, Benfante, Antonio, PERNICE, Riccardo, STIVALA, Salvatore, CALANDRA, Enrico, BUSACCA, Alessandro, Zeiss, L, Pernice, W. H. P, Danneau, R., Giambra, M A, Zeiss, L, Benfante, A, Pernice, R, Stivala, S, Calandra, E, Busacca, A, Pernice, W H P, and Danneau, R.
- Subjects
Graphene, Graphene Field Effect Transistors, Graphene microwave transistors - Abstract
In this work, we investigated on microwave parameters geometry dependence in Graphene Field Effect Transistors (GFETs). A DC and RF characterization of the fabricated GFETs has been performed. The parametric analysis was carried out on 24 GFET families fabricated on the same chip and differing only for the channel length (Δ) and the gate length (Lg). In order to obtain a statistical average, each family included ten devices with the same geometry.Our study demonstrates that the output resistance and the cut-off frequency depend on both Δ and Lg. As expected, Rout increases with the graphene channel surface thus confirming the good quality of the fabrication procedures. An optimum region which maximizes the cut-off frequency has been found.
- Published
- 2016
24. Cardiovascular parameters detection using a Photoplethismographic system
- Author
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GUARINO, Saverio, PARISI, Antonino, ANDO', Andrea, PERNICE, Riccardo, ADAMO, Gabriele, ZINGALES, Massimiliano, BUSACCA, Alessandro, Guarino, S, Parisi, A, Andò, A, Pernice, R, Adamo, G, Zingales, M, and Busacca, A
- Subjects
PPG ,Cardiovascular ,Settore ING-INF/01 - Elettronica ,Photoplethismographic - Abstract
We propose an innovative, cost-effective and easy to employ photoplethysmographic (PPG) system using Silicon Photomultipliers (SiPMs) sensors to measure cardiovascular parameters that can potentially represent markers for arterial stiffness
- Published
- 2016
25. Light Soaking measurements on Ruthenium-based Dye Sensitized Solar Cells
- Author
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PARISI, Antonino, PERNICE, Riccardo, ANDO', Andrea, CINO, Alfonso Carmelo, BUSACCA, Alessandro, Parisi, A, Pernice, R, Andò, A, Cino, AC, and Busacca, A
- Subjects
solar cell ,photovoltaic ,electro-optical characterization ,Settore ING-INF/02 - Campi Elettromagnetici ,DSSC ,Settore ING-INF/01 - Elettronica - Abstract
An interesting phenomenon occurring in Dye Sensitized Solar Cells (DSSCs) when exposed to an uninterrupted period of illumination is the so-called light soaking effect, which consists in the increase of the main electrical parameters of the cell, such as the photocurrent and the efficiency. Studying such an effect has noteworthy practical implications, ranging from the optimization of the manufacturing process to stability tests of DSSCs. In this paper, we present an experimental investigation on the performance variation, due to light soaking, of Ruthenium-based DSSCs.
- Published
- 2016
26. Photoelectric valuation of highly efficient Dye-Sensitized Solar Cells
- Author
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PARISI, Antonino, DI GARBO, Chiara, PERNICE, Riccardo, ADAMO, Gabriele, CINO, Alfonso Carmelo, LIVRERI, Patrizia, Ricco Galluzzo, F, Calogero, G, Di Marco, G, Vasi, C, BUSACCA, Alessandro, Parisi, A, Di Garbo, C, Pernice, R, Adamo, G, Cino, AC, Livreri, P, Ricco Galluzzo, F, Calogero, G, Di Marco, G, Vasi, C, and Busacca, A
- Subjects
solar cell ,photovoltaic ,electro-optical characterization ,Settore ING-INF/02 - Campi Elettromagnetici ,DSSC ,Settore ING-INF/01 - Elettronica - Abstract
Nowadays, a growing demand for free and clean energy requires the study and the development of new low-cost solar photovoltaic (PV) cells. Among them, Dye Sensitized Solar Cells (DSSCs) based on ruthenium complexes as sensitizers are assuming a great importance. The DSSCs under study are composed placing in succession a transparent conductive glass on which is screen-printed a mesoporous TiO2 thin film sensitized by a ruthenium based dye (N719) , an electrolytic solution containing a redox couple (I-/I3-) and another conductive glass covered by a thin transparent catalyst platinum film. In this work, we have measured the main photoelectrochemical parameters of the above mentioned DSSCs at different irradiance levels, incident wavelengths, temperatures and hours of light soaking.
- Published
- 2015
27. Fabrication and electro-optical characterization of Ruthenium-based Dye-Sensitized Solar Cells
- Author
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PARISI, Antonino, DI GARBO, Chiara, PERNICE, Riccardo, ADAMO, Gabriele, CINO, Alfonso Carmelo, LIVRERI, Patrizia, Ricco Galluzzo, F, BUSACCA, Alessandro, Calogero, G, Di Marco, G, Vasi, C., Parisi, A, Di Garbo, C, Pernice, R, Adamo, G, Cino, AC, Livreri, P, Ricco Galluzzo, F, Busacca, A, Calogero, G, Di Marco, G, and Vasi, C
- Subjects
Laser Beam Induced Current (LBIC) ,Dye Sensitized Solar cells (DSSCs) ,electro-optical characterization ,Settore ING-INF/02 - Campi Elettromagnetici ,Photovoltaic ,Settore ING-INF/01 - Elettronica - Abstract
In this paper, we measure the main photoelectrical parameters of Dye Sensitized Solar Cells (DSSCs) based on ruthenium complexes at different irradiance levels, incident wavelengths, temperatures and hours of light soaking
- Published
- 2015
28. Characterization of thin film CIG(S,SE)2 submodules using solar simulator and laser beam induced current techniques (Versione estesa)
- Author
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PARISI, Antonino, ADAMO, Gabriele, PERNICE, Riccardo, INGUANTA, Rosalinda, STIVALA, Salvatore, CINO, Alfonso Carmelo, MICELI, Rosario, SUNSERI, Carmelo, BUSACCA, Alessandro, Ricco Galluzzo, F, CARUSO, Massimo, Oliveri, RL, Ferrara, G, GUARINO, Saverio, Parisi, A, Ricco Galluzzo, F, Caruso, M, Adamo, G, Pernice, R, Oliveri, RL, Ferrara, G, Inguanta, R, Guarino, S, Stivala, S, Cino, AC, Miceli, R, Sunseri, C, and Busacca, A
- Subjects
Laser Beam Induced Current (LBIC) ,Optical characterization ,Submodule ,Settore ING-INF/02 - Campi Elettromagnetici ,Settore CHIM/07 - Fondamenti Chimici Delle Tecnologie ,Semiconducting selenium compound ,Solar simulator ,Settore ING-INF/01 - Elettronica ,Electrical parameter - Abstract
In this work, the electrical and optical characterization of CIG(S, Se)2 sub-modules using both a solar simulator equipment and the Laser Beam Induced Current (LBIC) technique is presented. By using the solar simulator and a proper set-up, the electrical parameters of the modules at varying irradiance and temperatures are determined. In addition, the LBIC measurements are carried out to analyze the 2D photocurrent uniformity of the modules at two different wavelengths. Dispersion values of extracted parameters can be very useful for practically tuning the modelling stage at device/module level.
- Published
- 2015
29. Electro-optical characterization of highly efficient Dye-Sensitized solar cells
- Author
-
PARISI, Antonino, DI GARBO, Chiara, PERNICE, Riccardo, ADAMO, Gabriele, CINO, Alfonso Carmelo, LIVRERI, Patrizia, Ricco Galluzzo, F, Calogero, G, Di Marco, G, Vasi, C, BUSACCA, Alessandro, Parisi, A, Di Garbo, C, Pernice, R, Adamo, G, Cino, AC, Livreri, P, Ricco Galluzzo, F, Calogero, G, Di Marco, G, Vasi, C, and Busacca, A
- Subjects
photovoltaic ,electro-optical characterization ,Solar cell ,Settore ING-INF/02 - Campi Elettromagnetici ,DSSC ,Settore ING-INF/01 - Elettronica - Abstract
Nowadays, a growing demand for free and clean energy requires the study and the development of new low-cost solar photovoltaic (PV) cells. Among them, Dye Sensitized Solar Cells (DSSCs) based on ruthenium complexes as sensitizers are assuming a great importance. The DSSCs under study are composed placing in succession a transparent conductive glass on which is screen-printed a mesoporous TiO2 thin film sensitized by a ruthenium based dye (N719), an electrolytic solution containing a redox couple (I-/I3-) and another conductive glass covered by a thin transparent catalyst platinum film. In this work, we have measured the main photoelectrochemical parameters of the above mentioned DSSCs at different irradiance levels, incident wavelengths, temperatures and hours of light soaking.
- Published
- 2015
30. Characterization of Ruthenium-based Dye-Sensitized solar cells
- Author
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PARISI, Antonino, DI GARBO, Chiara, PERNICE, Riccardo, ADAMO, Gabriele, CINO, Alfonso Carmelo, LIVRERI, Patrizia, Ricco Galluzzo, F, Calogero, G, Di Marco, G, Vasi, C, BUSACCA, Alessandro, Parisi, A, Di Garbo, C, Pernice, R, Adamo, G, Cino, AC, Livreri, P, Ricco Galluzzo, F, Calogero, G, Di Marco, G, Vasi, C, and Busacca, A
- Subjects
solar, cell, dssc, ruthenium, solar cells ,Settore ING-INF/02 - Campi Elettromagnetici ,Settore ING-INF/01 - Elettronica - Abstract
In this paper, we measure the main photoelectrical parameters of Dye Sensitized Solar Cells (DSSCs) based on ruthenium complexes at different irradiance levels, incident wavelengths, temperatures and hours of light soaking.
- Published
- 2015
31. Comparison of short-term heart rate variability indexes evaluated through electrocardiographic and continuous blood pressure monitoring.
- Author
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Pernice, Riccardo, Javorka, Michal, Krohova, Jana, Czippelova, Barbora, Turianikova, Zuzana, Busacca, Alessandro, Faes, Luca, and Member, IEEE
- Subjects
- *
HEART beat , *BLOOD pressure , *ELECTROCARDIOGRAPHY , *GOLD standard , *PHOTOPLETHYSMOGRAPHY - Abstract
Heart rate variability (HRV) analysis represents an important tool for the characterization of complex cardiovascular control. HRV indexes are usually calculated from electrocardiographic (ECG) recordings after measuring the time duration between consecutive R peaks, and this is considered the gold standard. An alternative method consists of assessing the pulse rate variability (PRV) from signals acquired through photoplethysmography, a technique also employed for the continuous noninvasive monitoring of blood pressure. In this work, we carry out a thorough analysis and comparison of short-term variability indexes computed from HRV time series obtained from the ECG and from PRV time series obtained from continuous blood pressure (CBP) signals, in order to evaluate the reliability of using CBP-based recordings in place of standard ECG tracks. The analysis has been carried out on short time series (300 beats) of HRV and PRV in 76 subjects studied in different conditions: resting in the supine position, postural stress during 45° head-up tilt, and mental stress during computation of arithmetic test. Nine different indexes have been taken into account, computed in the time domain (mean, variance, root mean square of the successive differences), frequency domain (low-to-high frequency power ratio LF/HF, HF spectral power, and central frequency), and information domain (entropy, conditional entropy, self entropy). Thorough validation has been performed using comparison of the HRV and PRV distributions, robust linear regression, and Bland-Altman plots. Results demonstrate the feasibility of extracting HRV indexes from CBP-based data, showing an overall relatively good agreement of time-, frequency-, and information-domain measures. The agreement decreased during postural and mental arithmetic stress, especially with regard to band-power ratio, conditional, and self-entropy. This finding suggests to use caution in adopting PRV as a surrogate of HRV during stress conditions. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
32. Graphene Field-Effect Transistors Employing Different Thin Oxide Films: A Comparative Study.
- Author
-
Giambra, Marco A., Benfante, Antonio, Pernice, Riccardo, Miseikis, Vaidotas, Fabbri, Filippo, Reitz, Christian, Pernice, Wolfram H. P., Krupke, Ralph, Calandra, Enrico, Stivala, Salvatore, Busacca, Alessandro C., and Danneau, Romain
- Published
- 2019
- Full Text
- View/download PDF
33. CuInSe2/Zn(S,O,OH) junction by electrochemical and chemical route for photovoltaic applications (GE 2014)
- Author
-
OLIVERI, Roberto Luigi, INGUANTA, Rosalinda, FERRARA, Germano, PIAZZA, Salvatore, SUNSERI, Carmelo, PARISI, Antonino, CURCIO, Luciano, ADAMO, Gabriele, PERNICE, Riccardo, ANDO', Andrea, STIVALA, Salvatore, CINO, Alfonso Carmelo, BUSACCA, Alessandro, Rocca, V, Giordano, A, GUARINO, Saverio, Oliveri, RL, Inguanta, R, Ferrara, G, Piazza, S, Sunseri, C, Parisi, A, Curcio, L, Adamo, G, Rocca, V, Pernice, R, Andò, A, Stivala, S, Giordano, A, Guarino, S, Cino, AC, and Busacca, A
- Subjects
solar cell ,photovoltaic ,Settore ING-IND/23 - Chimica Fisica Applicata ,thin film ,CIGS ,Settore ING-INF/01 - Elettronica - Abstract
Electrodeposition is a convenient technique for the development of low cost materials for photovoltaic (PV) device processing. Using a single step electrodeposition route, several groups have fabricated CIS (CuInSe) and CIGS (CuInGaSe) films. One of the most important requirements for successful application of one-step electrodeposition film formation is the ability to control composition of the deposited films and to develop polycrystalline microstructures with a low surface roughness and high sintered density.
- Published
- 2014
34. HYDROGELS WITH ORDER POROSITY AT THE MESO-SCALE FOR SENSING
- Author
-
SABATINO, Maria Antonietta, PERNICE, Riccardo, ADAMO, Gabriele, STIVALA, Salvatore, PARISI, Antonino, D'ACQUISTO, Leonardo, BUSACCA, Alessandro, DISPENZA, Clelia, Sabatino, MA, Pernice, R, Adamo, G, Stivala, S, Parisi, A, D’Acquisto, L, Busacca, A, and Dispenza C
- Subjects
sensing - Published
- 2014
35. Fading mitigation coding techniques for space to ground free space optical communications
- Author
-
ANDO', Andrea, PERNICE, Riccardo, CURCIO, Luciano, STIVALA, Salvatore, MANGIONE, Stefano, GALLO, Pierluigi, GARBO, Giovanni, BUSACCA, Alessandro, Andò, A, Pernice, R, Curcio, L, Stivala, S, Mangione, S, Gallo, P, Garbo, G, and Busacca, A
- Subjects
Settore ING-INF/03 - Telecomunicazioni ,Space-to-Ground FSO links, time-series, rateless code ,fading mitigation ,Settore ING-INF/02 - Campi Elettromagnetici ,Optical Wireless Communication ,Settore ING-INF/01 - Elettronica - Published
- 2014
36. Signal to noise ratio measurements of silicon photomultipliers
- Author
-
ADAMO, Gabriele, AGRO', Diego, STIVALA, Salvatore, PARISI, Antonino, TOMASINO, Alessandro, CURCIO, Luciano, PERNICE, Riccardo, GIACONIA, Giuseppe Costantino, BUSACCA, Alessandro, FALLICA, G., Adamo, G, Agro', D, Stivala, S, Parisi, A, Tomasino, A, Curcio, L, Pernice, R, Giaconia, GC, Busacca, A, and FALLICA, G
- Subjects
photomultipliers, silicon, snr, detector ,Settore ING-INF/02 - Campi Elettromagnetici ,Settore ING-INF/01 - Elettronica - Abstract
We report on our signal to noise ratio (SNR) measurements carried out, in the continuous wave regime, on a novel class of silicon photomultipliers (SiPMs) fabricated in planar technology on silicon p-type substrate. SiPMs are large area detectors consisting of a parallel array of Geiger Mode APDs with individual integrated quenching resistors. Each photodiode is an independent photon counting microcell and is connected to a common analog output to produce a summation signal proportional to the number of detected photons [1], [2]. SNR of SiPMs is expressed by the ratio of the SiPM average signal current and the RMS deviation of the overall current (i.e., the overall shot noise current). The measured noise takes into account the shot noise, resulting from the photocurrent and the dark current, while background light is not present in our setup. Unlike the shot noise, SiPM average dark current is an offset term and it can be filtered through a simple external DC removal circuit and, for this reason, we discarded it.
- Published
- 2014
37. Signal to Noise Ratio of Silicon Photomultipliers: a study in the Continuous Wave Regime
- Author
-
ADAMO, Gabriele, AGRO', Diego, STIVALA, Salvatore, PARISI, Antonino, TOMASINO, Alessandro, CURCIO, Luciano, PERNICE, Riccardo, GIACONIA, Giuseppe Costantino, BUSACCA, Alessandro, FALLICA, G., Adamo, G, Agro', D, Stivala, S, Parisi, A, Tomasino, A, Curcio, L, Pernice, R, Giaconia, GC, Busacca, A, and FALLICA, G
- Subjects
Settore ING-INF/02 - Campi Elettromagnetici ,Settore ING-INF/01 - Elettronica ,sipm, snr, photomultiplier, noise, silicon - Abstract
We report on Signal to Noise Ratio measurements carried out, in the continuous wave regime, at different bias voltages, frequencies and temperatures, on a novel class of silicon photomultipliers fabricated in planar technology on silicon p-type substrate. Signal to Noise Ratio has been measured as the ratio of the photogenerated current, filtered and averaged by a lock-in amplifier, and the Root Mean Square deviation of the same current. The measured noise takes into account the shot noise, resulting from the photocurrent and the dark current. We have also performed a comparison between our SiPMs and a photomultiplier tube in terms of Signal to Noise Ratio, as a function of the temperature of the SiPM package and at different bias voltages. Our results show the outstanding performance of this novel class of SiPMs even without the need of any cooling system.
- Published
- 2014
38. Electrochemical and chemical synthesis of CIS/Zn(S,O,OH) for thin film solar cells
- Author
-
Ficicchia, A, Oliveri, RL, DI GARBO, Chiara, INGUANTA, Rosalinda, FERRARA, Germano, PIAZZA, Salvatore, SUNSERI, Carmelo, PARISI, Antonino, CURCIO, Luciano, ADAMO, Gabriele, PERNICE, Riccardo, CINO, Alfonso Carmelo, STIVALA, Salvatore, CUSUMANO, Pasquale, LIVRERI, Patrizia, BUSACCA, Alessandro, Ficicchia, A, Oliveri, RL, Inguanta, R, Ferrara, G, Piazza, S, Sunseri, C, Parisi, A, Curcio, L, Adamo, G, Pernice, R, Cino, AC, Stivala, S, Cusumano, P, Di Garbo, C, Livreri, P, and Busacca A
- Subjects
CuInSe2 ,Electrodeposition ,Solar Cell ,Thin Film ,Mo foil - Abstract
In this work, we are reporting results on the electrodeposition of the CuInSe2 thin films on molybdenum thin foil substrates. We have used an aqueous non-buffered electrolyte and a careful choice of deposition parameters to ensure a good quality and composition of the deposited films. In addition, CdS was replaced in the buffer layer with a wider bandgap Zn(S,O,OH) film obtained by chemical bath deposition. The deposited films were annealed in inert atmosphere at different temperatures. The influence of annealing temperature on the properties of the films is briefly discussed. Films were also characterized by photoelectrochemical and I-V measurements. Structural characterization was carried out by XRD and Raman spectroscopy. Results show the growth of good quality films with very uniform morphology and good chemical composition.
- Published
- 2014
39. Optical turbulence measurements and channel modeling of an indoor Free Space Optics link (Versione estesa)
- Author
-
PERNICE, Riccardo, ANDO', Andrea, PARISI, Antonino, CURCIO, Luciano, ADAMO, Gabriele, STIVALA, Salvatore, BUSACCA, Alessandro, Musso, D, Pernice, R, Andò, A, Musso, D, Parisi, A, Curcio, L, Adamo, G, Stivala, S, and Busacca, A
- Subjects
optical turbulence ,Settore ING-INF/03 - Telecomunicazioni ,Free Space Optic ,Gamma-Gamma model ,time-serie ,Settore ING-INF/01 - Elettronica - Abstract
In this work, we propose an indoor experimental set-up able to generate several optical turbulence conditions in a Free Space Optics link. Using this set-up, we prove the effectiveness of an irradiance time-series generator based on the Gamma-Gamma model and able to predict the irradiance fluctuations at the receiver, under both weak and moderate turbulence conditions.
- Published
- 2014
40. Fabrication and Characterization of Dye-Sensitized Solar Cells
- Author
-
Bongiovanni, A, Ficicchia, A, Calogero, G, Di Marco, G, Canicattì, R, DI GARBO, Chiara, Vasi, C, PARISI, Antonino, PALMISANO, Giovanni, CURCIO, Luciano, PERNICE, Riccardo, ROMANO, Pietro, VIOLA, Fabio, CINO, Alfonso Carmelo, STIVALA, Salvatore, ADAMO, Gabriele, CUSUMANO, Pasquale, LIVRERI, Patrizia, BUSACCA, Alessandro, Bongiovanni, A, Parisi, A, Ficicchia, A, Palmisano, G, Curcio, L, Calogero, G, Di Marco, G, Pernice, R, Romano, P, Viola, F, Cino, AC, Stivala, S, Canicattì, R, Adamo, G, Di Garbo, C, Cusumano, P, Livreri, P, Vasi, C, and Busacca, A
- Subjects
solar cell ,Fabrication ,thin film ,Characterization ,Settore ING-INF/02 - Campi Elettromagnetici ,DSSC ,Settore CHIM/07 - Fondamenti Chimici Delle Tecnologie ,Settore ING-INF/01 - Elettronica - Abstract
Among the next-generation solar cells, a predominant role is played by Dye sensitized solar cells (DSSC) based on ruthenium complexes as sensitizers. They take advantage of a photoelectrochemical system to transform solar radiation into electric energy. In fact, DSSCs represent a cost-effective alternative to traditional silicon-based photovoltaic devices and they do not require expensive and sophisticated apparatus for their fabrication. In this work, we have produced and tested ruthenium DSSCs. In particular, we have measured the main parameters of these cells, such as the electrical and power performances and the efficiency levels, at different irradiance levels and at different incident wavelengths. Our results show a maximum conversion efficiency between 11% and 12% in the range within 540 and 550 nm. The results are in a fairly good agreement with theoretical predictions, especially with regard to the dependence of the parameters on the irradiance levels. Nevertheless, there are some aspects that suggest the need for further and more detailed studies on the deterioration mechanisms and fabrication processes.
- Published
- 2014
41. Optical turbulence measurements and channel modeling of an indoor Free Space Optics link (Abstract)
- Author
-
PERNICE, Riccardo, ANDO', Andrea, PARISI, Antonino, CURCIO, Luciano, STIVALA, Salvatore, BUSACCA, Alessandro, Musso, D, Lionti, F, Giglio, F, Pernice, R, Andò, A, Musso, D, Lionti, F, Giglio, F, Parisi, A, Curcio, L, Stivala, S, and Busacca, A
- Subjects
optical turbulence ,time-correlated Gamma-Gamma channel model ,Settore ING-INF/03 - Telecomunicazioni ,Free Space Optic ,Settore ING-INF/01 - Elettronica ,indoor link - Published
- 2014
42. CulnSe2/Zn(S,O,OH) junction on Mo foil by electrochemical and chemical route for photovoltaic applications
- Author
-
OLIVERI, Roberto Luigi, INGUANTA, Rosalinda, FERRARA, Germano, PIAZZA, Salvatore, SUNSERI, Carmelo, PARISI, Antonino, CURCIO, Luciano, ADAMO, Gabriele, Rocca, V, PERNICE, Riccardo, ANDO', Andrea, STIVALA, Salvatore, Giordano, A, GUARINO, Saverio, CINO, Alfonso Carmelo, BUSACCA, Alessandro, Oliveri, RL, Inguanta, R, Ferrara, G, Piazza, S, Sunseri, C, Parisi, A, Curcio, L, Adamo, G, Rocca, V, Pernice, R, Andò, A, Stivala, S, Giordano, A, Guarino, S, Cino, AC, and Busacca, A
- Subjects
photovoltaicS ,Settore ING-IND/23 - Chimica Fisica Applicata ,Electrodeposition ,Solar Cell ,Settore ING-INF/02 - Campi Elettromagnetici ,Thin Film ,CulnSe2 ,Settore ING-INF/01 - Elettronica ,Mo foil - Abstract
Electrodeposition is a convenient technique for the development of low cost materials for photovoltaic (PV) device processing. Using a single step electrodeposition route, several groups have fabricated CIS (CuInSe) and CIGS (CuInGaSe) films [1]. One of the most important requirements for successful application of one-step electrodeposition film formation, is the ability to control composition of the deposited films and to develop polycrystalline microstructures with a low surface roughness and high sintered density. In this preliminary work, CIS films were produced by single bath electrodeposition finding the optimal conditions in order to achieve a dense film with high crystallinity and uniform, flat surfaces, which are of critical importance for photovoltaic applications. Electrodeposition was carried out in the potentiostatic mode using a conventional three-electrode configuration.
- Published
- 2014
43. Fading mitigation coding techniques for space to ground free space optical communications (Euro Med Telco 2014)
- Author
-
ANDO', Andrea, PERNICE, Riccardo, CURCIO, Luciano, STIVALA, Salvatore, MANGIONE, Stefano, GALLO, Pierluigi, CAMPANELLA, Matteo, GARBO, Giovanni, BUSACCA, Alessandro, Andò, A, Pernice, R, Curcio, L, Stivala, S, Mangione, S, Gallo, P, Campanella, M, Garbo, G, and Busacca, A
- Subjects
Space-to- Ground FSO link ,Settore ING-INF/03 - Telecomunicazioni ,fading mitigation ,rateless code ,Settore ING-INF/02 - Campi Elettromagnetici ,Optical Wireless Communication ,time-serie ,Settore ING-INF/01 - Elettronica - Abstract
In this manuscript, a Geostationary satellite-toground Free Space Optics (FSO) downlink channel model has been implemented, which is able to predict temporal irradiance fluctuations caused by scintillation at a wide range of turbulence conditions and for different values of the zenith angle. In order to mitigate fading events that occur in FSO communications, we have also tested the performance of three different families of Rateless Codes (Luby Transform, Raptor and RaptorQ) into our model and found that RaptorQ is the best candidate to mitigate errors in FSO links.
- Published
- 2014
44. Optical sensors for ethanol vapor based on polystyrene opals infiltrated with hydrogel
- Author
-
PERNICE, Riccardo, ADAMO, Gabriele, STIVALA, Salvatore, PARISI, Antonino, BUSACCA, Alessandro, SABATINO, Maria Antonietta, D'ACQUISTO, Leonardo, DISPENZA, Clelia, Spigolon, D, Pernice, R, Adamo, G, Stivala, S, Parisi, A, Busacca, A, Spigolon, D, Sabatino, MA, D’Acquisto, L, and Dispenza, C
- Subjects
Optical sensing and sensor ,Nanostructure fabrication ,Hydrogels ,Photonic crystal ,Settore CHIM/07 - Fondamenti Chimici Delle Tecnologie ,Settore ING-INF/01 - Elettronica ,Sensor - Abstract
This paper deals with a novel class of optical sensors for ethanol vapor, based on polystyrene opals infiltrated with a hydrogel sensitive to ethanol. Optical characterization of such opals has been performed, proving their effectiveness as sensors
- Published
- 2013
45. Photonic crystal hydrogel films responsive to ethanol vapors
- Author
-
SABATINO, Maria Antonietta, D'ACQUISTO, Leonardo, SPADARO, Giuseppe, ALESSI, Sabina, DISPENZA, Clelia, BUSACCA, Alessandro, PERNICE, Riccardo, ADAMO, Gabriele, STIVALA, Salvatore, PARISI, Antonino, Sabatino, MA, D'Acquisto, L, Spadaro, G, Alessi, S, Dispenza, C, Busacca, A, Pernice, R, Adamo, G, Stivala, S, and Parisi, A
- Subjects
Photonic crystal ,Settore CHIM/07 - Fondamenti Chimici Delle Tecnologie - Published
- 2013
46. Analytical Model for wideband THz sources and detectors based on Optical Rectification and Electro-Optic Sampling
- Author
-
Tomasino, A, Peccianti, M, Morandotti, R., PARISI, Antonino, STIVALA, Salvatore, PERNICE, Riccardo, CURCIO, Luciano, CINO, Alfonso Carmelo, BUSACCA, Alessandro, Tomasino, A, Parisi, A, Stivala, S, Pernice, R, Curcio, L, Cino, AC, Busacca, A, Peccianti, M, and Morandotti, R
- Subjects
Electro-optic sampling ,Terahertz sources, Terahertz detectors ,Optical rectification ,Terahertz radiation ,Settore ING-INF/02 - Campi Elettromagnetici ,Settore ING-INF/01 - Elettronica - Abstract
An analytical model describing a laser based set-up for wideband THz generation and detection is presented. Particular attention is focused on the main broadband phenomena, which occur when THz radiations have to be handled.
- Published
- 2013
47. 5th EOS Topical Meeting on Optical Microsystems, Poster OμS13_1569798553: Analytical Model for wideband THz sources and detectors based on Optical Rectification and Electro-Optic Sampling
- Author
-
Tomasino, A, Peccianti, M, Morandotti, R., PARISI, Antonino, STIVALA, Salvatore, PERNICE, Riccardo, CURCIO, Luciano, CINO, Alfonso Carmelo, BUSACCA, Alessandro, Tomasino, A, Parisi, A, Stivala, S, Pernice, R, Curcio, L, Cino, AC, Busacca, A, Peccianti, M, and Morandotti, R
- Subjects
Electro-optic sampling ,Terahertz detectors ,Optical rectification ,Terahertz radiation ,Terahertz source ,Settore ING-INF/02 - Campi Elettromagnetici ,Settore ING-INF/01 - Elettronica - Published
- 2013
48. Optical wireless GEO satellite-to-ground downlinks: rateless codes as solution for scintillation fading
- Author
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ANDO', Andrea, MANGIONE, Stefano, CURCIO, Luciano, PERNICE, Riccardo, GARBO, Giovanni, BUSACCA, Alessandro, Andò, A, Mangione, S, Curcio, L, Pernice, R, Garbo, G, and Busacca, A
- Subjects
Settore ING-INF/03 - Telecomunicazioni ,Settore ING-INF/02 - Campi Elettromagnetici ,Settore ING-INF/01 - Elettronica ,Free Space Optics, Rateless codes, LT codes, Raptor codes, RaptorQ codes, channel modeling - Abstract
Scintillation fading can corrupt a satellite-to-ground optical wireless links with burst errors. Rateless codes, suitable for erasure channel, are able to eliminate or to reduce these communication errors. We analyzed the performances of three different rateless codes in a simulated Geo satellite-to-ground downlink.
- Published
- 2013
49. Periodically nanostructured hydrogels for ethanol vapors sensing
- Author
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SABATINO, Maria Antonietta, Spigolon, D, ADAMO, Gabriele, PARISI, Antonino, D'ACQUISTO, Leonardo, PERNICE, Riccardo, STIVALA, Salvatore, BUSACCA, Alessandro, DISPENZA, Clelia, Sabatino, MA, Spigolon, D, D’Acquisto, L, Pernice, R, Adamo, G, Stivala, S, Parisi, A, Busacca, A, and Dispenza, C
- Subjects
nanostructured hydrogels, vapors sensing - Abstract
Chemical sensing using optics has been under extensive research all over the world during last decades and many optical chemical sensors are nowadays finding increasing applications in industry, environmental monitoring, medicine, biomedicine and chemical analysis. These optical sensors can be based on various optical principles, such as absorbance, reflectance or transmittance, luminescence and fluorescence, covering different regions of the spectrum (UV, visible, IR, NIR). Optical chemical sensors have several advantages over conventional electricity-based sensors, in terms of selectivity, immunity to electromagnetic interference, higher sensitivity, and they are also relatively inexpensive and minimally invasive. A wide class of optical chemical sensors is based on Photonic Crystals (PCs), i.e. regular arrays of materials with different refractive indices. In particular, they are artificial structures with a periodic dielectric function. In this paper, we present the optical characterization of a polystyrene opal, infiltrated with a stimuli responsive hydrogel specifically formulated to be sensitive to ethanol (EtOH), also in the presence of water. Stimuli-responsive hydrogels are interesting materials for sensing applications due to thefact that they can change their volume significantly in response to small alterations of certain environmental parameters. In fact, hydrogels are increasingly considered as responsive materials to generate active inverse opals fortheir ability to exhibit significant reversible diffraction shifts as a response of a variety of stimuli, such astemperature, pH and ionic strength, single molecules binding and mechanical forces.The stimuliresponsiveness must be accompanied by adequate elasticity and chemical stability forthe inverse opal to be able to survive, without collapsing, to the template removal process byorganic solvents (for polymer colloids) during preparation and to withstand repeated swelling/deswelling cycles when in use, as well as erosion due to prolonged exposure to the swelling medium. While there are interesting studies which report diffraction shifts in a wide region of the visible spectral region when e.g. a crosslinked 2-hydroxyethyl methacrylate (HEMA) hydrogel is exposed either to pure liquid water or to concentrated ethanol/water liquid solutions, at the best of our knowledge there are no equivalent studies which report on the ability of hydrogel inverse opals tospecifically respond to ethanol vapors when already swollen by water.The hydrogel network should be designed so that it can uptake and retain water, when exposed towater vapor-rich atmospheres, and further swell when the atmosphere which is exposed to isprogressively concentrated of ethanol vapors. For this purpose, 2-hydroxyethyl methacrylate (HEMA) was used as main building block for the network, for its known favorable Flory-Hugginsmixing parameter with ethanol; acrylic acid (AA) at two different ratios was also considered as co-monomerfor its affinity toward water and its contribution to hydrogel network mechanicalproperties, due to establishment of further crosslinking through strong secondary interactions;finally poly-ethylene glycol-200dimethacrylate (PEG200DMA) was used as crosslinking agent. The polymerization process combined a “cold” UV-photocrosslinking step and a thermal post-cure.Preliminary swelling studies in the presence of both liquid ethanol and ethanol vapors were carried out on the macrogel analogue as well as a dynamic mechanical thermal analysis to withdraw usefulinformation on the hydrogels mechanical spectra and validate both the formulation and curingprocess. The most promising of the two formulations was selected to infiltrate a polystyrene (PS)opal structure, which was generated onto pre-etched silica through self-assembly of PS nanoparticles. The periodically nanostructured hydrogel film (Fig.1) was then evaluated as active component of an ethanol vapor optical sensor by means of UV-Vis transmission measurements atthe variance of ethanol vapor concentration (Fig.2).
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- 2013
50. Numerical Model of THz sources and detectors based on Optical Rectification and Electro-Optic Sampling
- Author
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Tomasino, A, STIVALA, Salvatore, PERNICE, Riccardo, CURCIO, Luciano, BUSACCA, Alessandro, Tomasino, A, Stivala, S, Pernice, R, Curcio, L, and Busacca, A
- Subjects
THz-TDS ,Electro Optic Sampling ,Wideband THz source ,Settore ING-INF/02 - Campi Elettromagnetici ,Optical Rectification (OR) ,Ultrashort laser pulse ,Settore ING-INF/01 - Elettronica - Abstract
A model describing a laser based set-up for wideband THz generation and detection is presented. Particular attention is focused on the main broadband phenomena, which occur when THz radiations have to be handled.
- Published
- 2013
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