68994 research outputs found
Sort by
Evaluating the effectiveness of dynamic evacuation wayfinding signage systems: comparing real-world and immersive virtual reality experiments
No full textThe fire safety of building occupants can be improved by dynamic Emergency Wayfinding Signage systems (EWSs), since they can optimize path selection tasks thanks to real-time data. In view of costs and complexities of real-world testing of dynamic EWSs, Immersive Virtual Reality (IVR) can streamline their effectiveness assessments, increasing the number of reference scenarios and of involved participants. Nevertheless, the IVR reliability should be supported by cross-validation between real-world and IVR solutions. This work is aimed at comparing the effectiveness of a dynamic EWS in real-world and two IVR setups: a head-mounted display and a CAVE. The experiments involved 228 volunteers. The experiments investigated route selection on a real-world T-shaped layout, in a university building with and without simulated smoke and lighting. The effectiveness of a dynamic EWS was assessed using the Theory of Affordance. Differences in specific affordances exist between IVR and real-world tests. Nevertheless, the analysis of functional affordance (assessing the effectiveness of EWS in guiding occupants towards a safe area) shows that IVR tests provide similar results to real-world ones, by also not overestimating the EWS effectiveness. Differences among scenario conditions and CAVE or HMD tests were identified too. On the one hand, outcomes hence support outcomes of previous works, which remark that differences could be mainly due to the scenario brightness and to the level of immersion/presence in IVR. On the other hand, results encourage the use of IVR to actively contribute to preliminary behavioural-based design and testing of dynamic EWSs
Numerical Characterization of Rodent Exposure Imbalances in Large Reverberation Chambers
No full textIn the past two decades, reverberation chambers (RCs) have been increasingly utilized in large-scale rodent bioassays to study dose-response relationships for cancer and non-cancer biological endpoints. Computational radio-frequency (RF) dosimetry plays a critical role in the design of these studies, influencing key parameters such as RC size, number, cohort size, and exposure frequencies. Given the complexity of modeling animal-loaded RCs, simplified random plane-wave (PW) superposition techniques have often been used, though full-wave characterizations have also been explored. This study expands previous research by analyzing the effects of line-of-sight (LoS) elimination in the Università Politecnica delle Marche RC at 900 MHz, modeling 96 caged rodents. Using whole-body Specific Absorption Rate (wbSAR) as the key observable, the study highlights asymmetries in RC exposures, showing higher wbSAR values near the mode-stirrer. The study investigates field diffusers and cage repositioning strategies to mitigate these imbalances. Simulations conducted with Transmission-Line Matrix (TLM) and Finite Element Method (FEM) techniques reveal a weaker correlation between wbSAR and rodent mass than previously reported. These findings suggest that real-world RC configurations introduce exposure variations not necessarily captured by idealized Rayleigh field models, impacting the interpretation of rodent bioassay results
In between coral branches: describing the courtship behavior of the Mediterranean cardinalfish Apogon imberbis (Linnaeus, 1758)
No full textThe behavior of a pair of cardinalfish Apogon imberbis (Linnaeus, 1758) (Apogonidae) was investigated through the acquisition of time-lapse images at three-min-intervals over five consecutive days, encompassing both diurnal and nocturnal hours. We characterized the phases of courtship, quantified the frequency and alternation of activity patterns, and assessed their duration across the diel cycle, highlighting potential differences between sexes. The habitat preferences by A. imberbis associated to the red octocoral Paramuricea clavata (Risso, 1827) (Cnidaria, Anthozoa) were documented for the first time in the Mediterranean Sea. The pair exhibited pronounced diel behavioral patterns, with increased nocturnal activity likely linked to zooplankton foraging, and diurnal rest in shelters provided by the coral branches. The courtship consisted in three activities that were cyclically repeated throughout the day, with a total duration of 10.2 hours. The novel behavior named “patrolling” was played by the female after the mating event, presumably linked to the egg-laying site defense. The time-lapse technique offers the possibility to collect continuous, non-invasive observations at great depths and for prolonged periods, allowing for detailed surveys of the organisms, their interactions and the use of the habitat. The advantages and potentialities of this methodology could be further improved by machine learning programs for the recognition of animal activity patterns, allowing for the processing of massive dataset, reducing human workload and improving accuracy and time-efficiency
Evaluation of 77 GHz Radar for Industrial Fan Quality Inspection
No full textQuality inspection is crucial in production lines. During the fabrication process, defects and imperfections can be present and the affected manufactured parts must be discarded. Such process must be fast and reliable to not slow down the production line and assure that out of tolerance parts are always identified. Different methodologies are investigated and applied to perform the task, but for companies, it is always of interest to discover novel methods to improve the quality inspection process. In this work, the manufactured under test is an industrial fan, and the test methodology proposed leverages a radar sensor. Two main quantities are extracted: the fan's rotation speed and its vibration displacement. To validate the radar method, reference sensors are used. At the end, a comparison in measuring rotation speed and vibration displacement with the radar and the reference sensors is provided
Large-scale Digital Twin for Civil Infrastructure Management
No full textTutti gli ambiti della scienza sono oggi permeati dal paradigma della complessità. Lo studio dei sistemi complessi si pone come una vera e propria rivoluzione scientifica scaturita dall'evidenza empirica che la comprensione o "spiegazione" di molti sistemi reali non possa essere ridotta a relazioni causa-effetto semplici e deterministiche.
Le infrastrutture civili su larga scala sono sistemi complessi caratterizzati dalla reciproca interazione non lineare di molte componenti appartenenti a domini e scale differenti, ognuna delle quali, pur essendo autonoma, influenza il comportamento delle altre. Sono di fatto sistemi che manifestano spesso instabilità o equilibri dinamici che non possono essere desunti dalla semplice sovrapposizione delle leggi che governano le singole componenti. Ciò non solo per la rilevante complessità matematica del problema quanto per l’estrema variabilità dei risultati che si otterrebbero a fronte di piccolissime variazioni o mancata definizione dei dati di input che coinvolgono non solo lo stato corrente ma l’intera storia del sistema. Si può dunque affermare che, per tali sistemi, un approccio analitico classico non riesce a spiegarne il comportamento in modo significativo, né tantomeno a prevederne l'evoluzione futura, a meno di trattare una quantità e precisione di dati tale da rendere il modello matematico non operabile. Inoltre, nella pratica attuale, le analisi su infrastrutture civili su larga scala seguono puntualmente approcci tradizionali confinati in ambiti completamente isolati, privi della flessibilità necessaria per affrontare sfide che coinvolgono più discipline e più livelli di scala.
I dati più recenti includono l'assenza di visione sistemica tra i principali fattori di inefficienza nella gestione delle infrastrutture civili. Attualmente infatti, analisi multi-disciplinari e multi-livello sono gestite in ambienti di back-office attraverso processi di integrazione delle competenze che si rivelano spesso troppo lenti per una risposta in tempo reale, non riuscendo così a soddisfare efficacemente le esigenze operative e di emergenza. È pertanto necessaria una modellazione che catturi le relazioni multi-scala e multi-dominio e riveli i comportamenti emergenti del sistema e delle sue parti.
Il concetto di Digital Twin (DT) entra in gioco proprio per rispondere a queste sfide. I DT sono concepiti per analizzare sistemi in cui fenomeni estremamente eterogenei interagiscono reciprocamente e in cui anche piccoli stimoli provenienti da un singolo sottosistema possono influenzare significativamente altri sottosistemi, su diverse scale e in diversi domini. Un DT deve essere visto come un sistema di intelligenza collettiva, un'interpretazione condivisa della realtà che sincronizza sottosistemi multi-dominio e multi-scala mediante l'allineamento di agenti virtuali e reali, tra cui l’uomo. Un DT non può perciò essere concepito solo come uno strumento di simulazione, né come una semplice virtualizzazione dei sistemi fisici, pur includendoli. Il DT possiede un valore interpretativo e decisionale, che comporta sfide metodologiche e tecniche significative: rappresentare in tempo reale le relazioni tra gli agenti del sistema, laddove esistono, in funzione della loro rilevanza e pertinenza rispetto agli obiettivi di gestione. I DT modellano comportamenti sistemici emergenti e diagnosticano potenziali criticità, con capacità anche previdenziali. A differenza delle tipiche metodologie di inferenza come quelle causali, sufficienti per analisi di sistemi semplici, i DT osservano gli effetti e diagnosticano le potenziali cause, favorendo un processo decisionale informato e predittivo in tempo reale.
In questa chiave, in questo lavoro di tesi si persegue una modellazione della realtà orientata verso un approccio digitale, che consente di inquadrare interazioni multi-scala e multi-dominio, contribuendo alla costruzione di un DT multi-modello per la gestione di infrastrutture civili su larga scala. La ricerca ha comportato un impegno collaborativo nello sviluppo di un'architettura di piattaforma cloud di DT e dei suoi componenti implementativi. Al centro del framework sviluppato si trova un nucleo di concertazione che orchestra molteplici microservizi e strumenti specializzati, tra cui anche algoritmi di intelligenza artificiale e computer vision. Si è definito un ambiente in cui agenti virtuali e reali sono sincronizzati per realizzare un DT su larga scala finalizzato alla gestione di infrastrutture civili, con particolare attenzione alla rappresentazione digitale delle interazioni tra sottosistemi multi-dominio e multi-scala, sviluppando metodologie, procedure e tecnologie di digital twinning per:
1. strutturare semanticamente dati eterogenei,
2. allineare geometricamente e semanticamente modelli di dati multi-dominio e -scala (registrazione),
3. automatizzare le registrazioni, anche bidirezionali (modello-campo) per abilitare ispezioni digitali,
4. rappresentare le relazioni multi-dominio e -scala, pertinenti e rilevanti, tra le informazioni e gli agenti presenti nel DT (contestualizzazione).
Valutazioni sia qualitative che quantitative delle procedure implementate sono state eseguite in laboratorio con conseguente applicazione sul campo, prendendo come riferimento scenari complessi definiti da sistemi di infrastrutture civili di grande scala.
L’approccio di digital twin e le soluzioni proposte in questo lavoro comportano innovazioni sostanziali rispetto all’attuale stato dell’arte e, in ultima analisi, hanno contribuito a definire una piattaforma cloud di DT per la gestione delle infrastrutture civili su larga scala unica nel suo genere.Today, the paradigm of complexity permeates all scientific fields. The study of complex systems represents a true scientific revolution, arising from empirical evidence that understanding or "explaining" many real-world systems cannot be reduced to simple, deterministic cause-effect relationships.
Large-scale civil infrastructures are complex systems featuring nonlinear, interdependent interactions among numerous components across different domains and scales. Each component, though autonomous, influences the behavior of others, often resulting in dynamic equilibria or instabilities that cannot be deduced by merely combining the rules governing individual components. This is not only due to the mathematical intricacy of the problem but also because of the extreme variability in outcomes that can arise from minimal changes or insufficient definition in input data, affected not only by the current state but also by the entire history of the system. Consequently, for such systems, a classical analytical approach fails to provide significant insights or reliable future predictions without an impractically large and precise data volume, rendering the mathematical model inoperable. Furthermore, in current practice the analysis of large-scale civil infrastructures is often confined within isolated, vertical domains, lacking the flexibility needed to address cross-domain and cross-scale challenges.
Data indicates that the absence of a systemic view is a major contributor to inefficiencies in infrastructure management. Presently, such interactions are managed in back-office environments through expertise integration processes that are often too slow for real-time response, failing to meet operational and emergency needs effectively. A representation that captures multi-scale, multi-domain relationships and reveals emergent behaviors of the system and its components is therefore required.
The aim of Digital Twins (DTs) is to address these challenges. DTs are meant to analyze systems where heterogeneous phenomena interact, and where even minor inputs from one subsystem can significantly impact others across scales and domains. A DT should be viewed as a system of collective intelligence—a shared interpretation of reality that synchronizes multi-domain and multi-scale subsystems by aligning both virtual and real (also human) agents. A DT cannot solely be thought as a traditional simulation tool, nor simply a virtualization of physical systems, although including them. It holds interpretive and decision-making value, which brings a significant technical challenge: representing in real time system agent’s relationships, where they exist, according to a single criterion which is their relevance and significance to management objectives. DTs can thus be used to represent systemic emergent behaviors and diagnose potential issues. Unlike typical inference methodologies (e.g., top-down causal inferences), which suffice for analyzing simple systems, DTs observe effects and diagnose potential critical phenomena with predictive capabilities, supporting informed decision-making.
In this thesis, a digital modeling approach is pursued, enabling the representation of multi-scale and multi-domain phenomena interactions, contributing to the development of a multi-model DT for the management of large-scale civil infrastructure systems. The research involved collaborative efforts to develop a Digital Twin cloud platform architecture and its implementation components (tools and microservices). At the core of the developed framework lies a concertation core that orchestrates multiple specialized microservices. We developed an environment where virtual and real agents are synchronized to realize the large-scale DT for civil infrastructure management, focusing primarily on the representation of interactions among multi-domain, multi-scale subsystems by developing digital twinning methodologies, procedures, and technologies for:
1. structuring heterogeneous data semantically,
2. achieving geometric and semantic alignment of multi-domain and -scale data models (registration),
3. establishing automatic, bidirectional (field-model) registration systems for digital inspections,
4. representing relationships among multi-domain and -scale information and agents (contextualization).
Qualitative and quantitative evaluations of the implemented procedures were performed in laboratory with subsequent field deployment.
Both the digital twinning approach and vertical analytical solutions proposed in this work represent substantial innovations compared to the current state of the art and ultimately helped define a unique DT cloud platform built on methodological choices and technological solutions that overcome the cited critical limitations found in today’s approaches and systems for civil infrastructure management
Nut Consumption Is Associated with Cognitive Status in Southern Italian Adults
No full textBackground: Nut consumption has been considered a potential protective factor against cognitive decline. The aim of this study was to test whether higher total and specific nut intake was associated with better cognitive status in a sample of older Italian adults. Methods: A cross-sectional analysis on 883 older adults (>50 y) was conducted. A 110-item food frequency questionnaire was used to collect information on the consumption of various types of nuts. The Short Portable Mental Status Questionnaire was used to assess cognitive status. Multivariate logistic regression analyses were performed to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for the association between nut intake and cognitive status after adjusting for potential confounding factors. Results: The median intake of total nuts was 11.7 g/day and served as a cut-off to categorize low and high consumers (mean intake 4.3 g/day vs. 39.7 g/day, respectively). Higher total nut intake was significantly associated with a lower prevalence of impaired cognitive status among older individuals (OR = 0.35, CI 95%: 0.15, 0.84) after adjusting for potential confounding factors. Notably, this association remained significant after additional adjustment for adherence to the Mediterranean dietary pattern as an indicator of diet quality, (OR = 0.32, CI 95%: 0.13, 0.77). No significant associations were found between cognitive status and specific types of nuts. Conclusions: Habitual nut intake is associated with better cognitive status in older adults
Hydrogeochemical evaluation of Caleta de Los Loros Patagonian salt marsh in response to the geomorphological evolution of the coast during the Holocene
No full textSea level oscillations occurred during the Quaternary conditioned the marsh landscape by limiting the factors that regulate water salinity in this environment. The aim of this work was to evaluate geochemical processes that condition groundwater salinity in Caleta de Los Loros marsh considering geomorphological – climatic factors associated with the Holocene evolution of this Argentinean Patagonia coastal area. In this sense, a mapping and a geomorphological characterization was performed based on satellite images, digital elevation models and field surveys. A monitoring network including both surface and groundwater was made in order to measure in situ pH and electrical conductivity and to take samples to determine major ions and stable isotopes in the laboratory. The set of results obtained highlights that variations in salinity, major ions composition and isotopic signal recorded in the groundwater of Caleta de Los Loros marsh vary in the different sectors of the intertidal plains resulting from geomorphological evolution from the middle Holocene to the present day. The older intertidal deposits (2100 years B.P.) currently located in the more continental sector host high salinity environments with high marshes vegetated with Salicornia sp. The hydrochemical and isotopic signal indicates that in them salinity responds primarily to evaporitic salt dissolution – precipitation cycles. Meanwhile, more coastal intertidal deposits have less than 500 years and they host low marsh environments vegetated with Spartina sp. Hydrochemistry and isotopic composition in them reflect that tidal water flooding is the main water contribution to the system, being marsh groundwater hydrogeochemichally similar to surface water. Locally, contributions from adjacent beach ridges and hydrochemical variations associated with CO2(g) dissolution were also recognized. Understanding environmental changes that occur in marshes as a product of their geomorphological quaternary evolution allows to understand the distribution of salinity patterns that develop in them and to give an idea of the time scale on which the salinization of these environments occur
Investitori retail e equity crowdfunding: pronti per l’innovazione finanziaria?
No full textQuesto studio esamina le determinanti dell’intenzione di investimento in equity crowdfunding (Ecf), strumento di finanza innovativa e segmento dell’ecosistema FinTech, tra gli investitori retail. I risultati del modello di equazioni strutturali evidenziano il ruolo centrale dell’alfabetizzazione finanziaria digitale nella formazione delle intenzioni di investimento. L’«effetto gregge» influisce significativamente sulle decisioni di investimento, sottolineando la natura sociale delle piattaforme Ecf. Contrariamente alle teorie convenzionali, lo studio mette in discussione la presunta importanza delle informazioni di tipo quantitativo sulle nuove imprese e sulle campagne di raccolta nell’influenzare le intenzioni di investimento in Ecf. Lo studio suggerisce implicazioni per i programmi di alfabetizzazione finanziaria e per la gestione proattiva dell’effetto gregge e offre futuri spunti di ricerca.This study examines the determinants of investment intention in equity crowdfunding (Ecf) – which is an innovative financial instrument and segment of the FinTech ecosystem – among retail investors. Results from the Structural Equation Model highlight the pivotal role of digital finance literacy in shaping investment intentions in FinTech. Herd behavior significantly impacts investment decisions, emphasizing the social nature of Ecf platforms. Contrary to conventional theories, the study challenges the presumed importance of hard information about new ventures and fundraising campaigns in influencing investment intentions in Ecf. The study suggests implications for financial literacy programs and proactive management of herd behavior and offers insights for future research
PIANIFICAZIONE PERFORMANCE-BASED PER LA RIDUZIONE DELLA VULNERABILITÀ SISMICA URBANA Framework metodologico per azioni di resilienza urbana nei Piccoli comuni
No full textIl Sendai Framework attribuisce alla dimensione locale, compresa quella di natura privata, una rinnovata centralità nelle politiche di mitigazione e di prevenzione dei rischi ambientali, riconoscendo che le istituzioni non possono agire da sole e che tutte le parti interessate hanno la responsabilità di ridurre i livelli di rischio. Affinché le politiche di mitigazione e prevenzione trovino una propria espressione operativa, la pianificazione urbanistica ricopre un ruolo cardine per coordinare l’azione e per costruire una dimensione di resilienza urbana.
La ricerca indaga il concetto di resilienza urbana associato alla dimensione spaziale dei Piccoli comuni, un campo solo parzialmente esplorato in letteratura. Dall’analisi dello stato dell’arte emerge che in questi contesti il tema della mitigazione è affidato quasi esclusivamente ad azioni pubbliche di ripristino-recupero post calamità. Riscontrata questa evidenza, la ricerca si è posta come obiettivo lo sviluppo di un framework metodologico per sistematizzare azioni di resilienza urbana (pubbliche e private) negli strumenti di pianificazione urbanistica dei Piccoli comuni. L’attività di ricerca si focalizza sul rischio sismico urbano, per definire una strategia integrata e un’architettura normativa per i piani urbanistici, ponendo alla base del framework un apparato di regole performance-based per ridurre la vulnerabilità sismica urbana. Il framework definisce una gerarchia di regole performative incentrata sui parametri e sugli indici di vulnerabilità e di esposizione. In questa gerarchia, l’indice di esposizione assume il ruolo di valore obiettivo di controllo, e l’indice di vulnerabilità svolge la funzione di parametro d’azione per lo sviluppo della resilienza urbana. Questo paradigma normativo può favorire un funzionamento urbano auto-adattivo, nel quale è consentita la libera collocazione di usi e funzioni purché non si creino effetti negativi al sistema.
Utilizzando tecnologie geospaziali, il metodo è stato sperimentato attraverso ipotesi scenariali e sono stati confrontati i rispettivi risultati. Dalla disamina degli scenari emerge come anche un singolo intervento di cambio di destinazione d’uso può incidere notevolmente sull’esposizione urbana. La strategia di mitigazione alla base del framework, sfrutta la progressiva evoluzione del sistema socio-culturale ed economico locale per ridurre i livelli di rischio e far convergere azione pubblica e privata. Il paradigma si configura come una concatenazione di “tecniche urbanistiche”, in cui la valutazione della vulnerabilità rappresenta una componente indipendente connessa ad un telaio normativo incentrato sull’esposizione.The Sendai Framework highlights the role of the local dimension, including the private sector, in environmental risk mitigation and prevention policies, recognizing that institutions cannot act alone and that all stakeholders share responsibility for reducing risk levels. For mitigation and prevention policies to achieve operational effectiveness, urban planning plays a pivotal role in coordinating actions and fostering urban resilience.
This research explores the concept of urban resilience associated with the spatial dimension of small towns, a field only partially addressed in the literature. A review of the state of the art reveals that, in these contexts, mitigation efforts are almost exclusively reliant on public post-disaster restoration and recovery actions. Acknowledging this, the research aims to develop a methodological framework to systematize urban resilience actions (both public and private) within the urban planning tools of small towns. The study focuses on urban seismic risk, defining an integrated strategy and a regulatory framework for urban planning, with performance-based rules at the core of the framework to reduce urban seismic vulnerability.
The framework establishes a hierarchy of performance-based rules centered on vulnerability and exposure parameters and indices. Within this hierarchy, the exposure index serves as a control target, while the vulnerability index functions as an operational parameter for developing urban resilience. This paradigm can promote a self-adaptive urban system, allowing for the flexible placement of uses and functions as long as no negative impacts are created within the system.
Using geospatial technologies, the method was tested through scenario-based hypotheses, and the respective results were compared. The scenario analysis highlights that even a single change in land use can significantly impact urban exposure. The mitigation strategy underpinning the framework leverages the progressive evolution of the local socio-cultural and economic system to reduce risk levels and align public and private actions. The paradigm is structured as a chain of "urban planning techniques," where vulnerability assessment is an independent component connected to a regulatory framework focused on exposure