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Learning-driven and distributed optimal control methods for large-scale and multi-agent systems
Get PDFIn recent years, the interest of the control community in large-scale systems has surged, driven by their capacity to encompass behaviors integrating human and cyber-physical resources. The complexity of these systems, characterized by several interconnected units, represents a significant challenge when developing effective optimal control policies. This topic is addressed in this thesis from a threefold perspective: (i) tackling the complex nature of such settings by leveraging data-driven strategies over traditional model-based approaches, (ii) taking advantage of the interconnections typical of these large-scale applications at design level, and (iii) developing efficient and scalable centralized and distributed optimal control algorithms.
We start by developing data-driven strategies for the resolution of the Linear Quadratic Regulator problem when the underlying dynamics are unknown. First, we propose an on-policy algorithm, where the system is identified while simultaneously optimizing the control policy. Second, we design data-driven algorithms to generate controllers that adhere to particular structural constraints, such as mirroring the inherent patterns of the large-scale system.
Subsequently, we develop a first-order framework for nonlinear optimal control tailored to large-scale systems. This centralized methodology is then extended to the distributed optimal control setting. Here, we tackle a novel problem formulation that leverages the aggregative optimization framework, an approach designed to encapsulate collective behaviors. We then propose a data-driven version of the approach, based on a concurrent optimization and learning scheme. Eventually, the proposed methodology is extended to the stochastic optimal control scenario.
Finally, we consider the challenge of developing safe-by-design control policies within the multi-layer control formalism. This framework is tailored to analyzing the control architectures traditionally deployed in robotics applications, where a low-level, easy-to-deploy control policy interacts with a more advanced high-level planning strategy. In this context, we present an optimization-based trajectory generation strategy, ensuring compliance to safety-critical constraints, designed for multi-layer control architectures
Managing sustainability and efficiency: market and non-market value approaches in Mediterranean fisheries
No full textThis thesis contributes to natural resource management in Mediterranean fisheries by integrating market and non-market value perspectives, linking environmental and economic analyses. It emphasizes the necessity of quantifying the entirety of fisheries values while stressing the importance of efficient, sustainable resource management.
The first chapter scrutinizes the effectiveness of Fisheries Local Action Groups in steering sustainable development in maritime areas. Reviewing previous studies through the lens of Porter’s Diamond, we explore how FLAGs influence coastal community competitiveness. The findings underscore potential implications for the adoption of Community-Led Local Development strategies, particularly within the European Maritime, Fisheries and Aquaculture Fund framework for 2021-2027.
The second chapter investigates the economic externality created by small-scale fishing ports. Using a travel cost approach, we assess the value that visitors place on recreational activities offered by these ports. Unveiling substantial consumer surplus from artisanal ports, this chapter highlights the potential of diversifying income sources for coastal communities and advocates for small-scale fishery sector support.
The third chapter focuses on vessels efficiency in the rapido fishery of Chioggia through stochastic frontier analysis and catch profile examination. By identifying fishing strategies with optimal performance in terms of revenue generation and carbon footprint, this chapter aims to improve efficiency in one of the most problematic segments of the Adriatic Sea’s large-scale fleet.
Lastly, the fourth chapter extends the efficiency analysis by investigating price formation, seasonality effects, and price-quantity relationships for primary species targeted by rapido vessels. Examining fishers' tendencies towards revenue maximization, this chapter seeks to provide insights for fisheries management, emphasizing the need for adaptable approaches in the Mediterranean context.
Overall, this thesis aims to contribute to the ongoing discourse on the adaptability and flexibility required in managing Mediterranean fisheries, recommending more nuanced and responsive strategies in the face of dynamic market conditions and environmental challenges
The impact of dupilumab on conditioning patch tests in patients with atopic dermatitis.
Get PDFIntroduzione
La dermatite atopica (DA) è una malattia infiammatoria cronica della pelle caratterizzata da alterazioni della barriera cutanea con una prevalente via infiammatoria TH2. Il decorso clinico dell'DA può essere complicato dalla presenza di dermatite allergica da contatto (DAC). Sebbene la DAC rappresenti una reazione di ipersensibilità di tipo IV, studi cellulari suggeriscono che alcuni allergeni più deboli possono suscitare risposte immunitarie di tipo TH1, TH2, TH 22 e TH 17. Dupilumab, un farmaco approvato per il trattamento dell'AD moderato-grave, inibisce la trasduzione del segnale di IL-4 e IL-13 bloccando i meccanismi di segnalazione della via TH2.
Obbiettivo
L’obiettivo dello studio era valutare l'attendibilità dei patch test nei pazienti sottoposti a terapia con dupilumab, la prevalenza di DAC nei pazienti con DA moderato-grave, le classi di allergeni prevalenti e maggiormente interessati dal trattamento.
Materiali e metodi
Sono stati reclutati 92 pazienti adulti con DA moderato-grave. I pazienti sono stati sottoposti a patch test prima di iniziare il trattamento con dupilumab e, solo nei pazienti risultati positivi, dopo 32 settimane di trattamento, sono stati ripetuti i patch test, confrontando i risultati.
Risultati
Abbiamo osservato una prevalenza di sensibilizzazione del 29,34% (27/92). Le categorie di apteni risultati positivi corrispondevano in ordine di frequenza a metalli (16,3%), profumi (8,7%) e conservanti (5,3%). Dal nostro studio è emerso che il 72,7% delle positività osservate prima del trattamento con dupilumab si sono conservate anche dopo 32 settimane di terapia.
Conclusione
Dupilumab non sembra influenzare i risultati del patch test. La perdita di positività è stata del 18,2% e ciò suggerisce che, sebbene la maggior parte delle positività sia stata mantenuta durante il trattamento con dupilumab, alcune reazioni del patch test nei pazienti trattati potrebbero essere soppresse. In ogni caso, non è mai consigliabile interrompere Dupilumab prima di eseguire i patch test.Introduction
Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by alterations of the skin barrier with a prevalent TH2- inflammation pathway. The clinical course of AD can be complicated by the presence of allergic contact dermatitis (ACD). Although ACD represents a type IV hypersensitivity reaction, cellular studies suggest that some weaker allergens can elicit immune responses of TH1, TH2, TH 22 and TH 17 types. Dupilumab, a drug approved for the treatment of moderate-severe AD, inhibits the signal transduction of IL-4 and IL-13 by blocking the signaling mechanisms of TH2 pathway.
Objective
The objective of the study was to evaluate the reliability of patch tests in patients undergoing therapy with dupilumab, the prevalence of ACD in patients with moderate-severe AD, the classes of allergens prevalent and most affected by the treatment.
Materials and methods
92 adults patients with moderate-severe AD were recruited. Patients underwent patch tests before starting treatment with dupilumab and, only in patients who tested positive, after 32 weeks of treatment, patch tests were repeated, comparing the results.
Results
We observed a sensitization prevalence of 29.34% (27/92). The categories of haptens tested positive corresponded in order of frequency to metals (16.3%), fragrances (8.7%) and preservatives (5.3%). Our study showed that 72.7% of the positivities observed before treatment with dupilumab were preserved even after 32 weeks of therapy.
Conclusion
Dupilumab does not appear to affect patch test results. The loss of positivity was 18.2% and this suggests that, although most positivities were maintained during treatment with dupilumab, some patch test reactions in treated patients may be suppressed. In any case, it is never recommended to stop Dupilumab before patch testing
The role of payments in digital finance
Get PDFThis thesis investigates the role of payment in digital finance through a collection of papers that delve into theoretical, empirical, and policy-centric aspects. The first paper sets the thesis in the domain of policy-relevant research and connects the literature on digital finance with current policy discussions. The review covers topics such as technology-based lending, distributed ledger technology, and the impact of emerging technologies on supervisors' practices. It highlights the need for collaborative efforts between academia and supervisors to propel future research. The second paper analyses the impact of open banking policy on financial intermediaries. It examines the effects of open banking frameworks on loan interest rates and emphasizes the role of regulators in mitigating challenges. The third paper investigates the role of payments in financial intermediation, especially during the COVID-19 pandemic. It highlights the impact of payment systems on systemic risk and emphasizes the importance of an optimized capital structure and timely government intervention in averting liquidity shocks. In conclusion, this thesis offers nuanced insights into digital finance, covering policy implications, open banking frameworks, and systemic risk dynamics. It provides a comprehensive understanding of the evolving financial landscape and is relevant to academic discourse and policy-makers
Unveiling the expansion history of the universe with cosmic chronometers and gravitational waves
Get PDFThis Thesis explores two novel and independent cosmological probes, Cosmic Chronometers (CCs) and Gravitational Waves (GWs), to measure the expansion history of the Universe. CCs provide direct and cosmology-independent measurements of the Hubble parameter H(z) up to z∼2. In parallel, GWs provide a direct measurement of the luminosity distance without requiring additional calibration, thus yielding a direct measurement of the Hubble constant H0=H(z=0). This Thesis extends the methodologies of both of these probes to maximize their scientific yield. This is achieved by accounting for the interplay of cosmological and astrophysical parameters to derive them jointly, study possible degeneracies, and eventually minimize potential systematic effects. As a legacy value, this work also provides interesting insights into galaxy evolution and compact binary population properties. The first part presents a detailed study of intermediate-redshift passive galaxies as CCs, with a focus on the selection process and the study of their stellar population properties using specific spectral features. From their differential aging, we derive a new measurement of the Hubble parameter H(z) and thoroughly assess potential systematics. In the second part, we develop a novel methodology and pipeline to obtain joint cosmological and astrophysical population constraints using GWs in combination with galaxy catalogs. This is applied to GW170817 to obtain a measurement of H0. We then perform realistic forecasts to predict joint cosmological and astrophysical constraints from black hole binary mergers for upcoming gravitational wave observatories and galaxy surveys. Using these two probes we provide an independent reconstruction of H(z) with direct measurements of H0 from GWs and H(z) up to z∼2 from CCs and demonstrate that they can be powerful independent probes to unveil the expansion history of the Universe
An architecture for network acceleration as a service in the cloud continuum
Get PDFThe pervasive availability of connected devices in any industrial and societal sector is pushing for an evolution of the well-established cloud computing model. The emerging paradigm of the cloud continuum embraces this decentralization trend and envisions virtualized computing resources physically located between traditional datacenters and data sources. By totally or partially executing closer to the network edge, applications can have quicker reactions to events, thus enabling advanced forms of automation and intelligence. However, these applications also induce new data-intensive workloads with low-latency constraints that require the adoption of specialized resources, such as high-performance communication options (e.g., RDMA, DPDK, XDP, etc.). Unfortunately, cloud providers still struggle to integrate these options into their infrastructures. That risks undermining the principle of generality that underlies the cloud computing scale economy by forcing developers to tailor their code to low-level APIs, non-standard programming models, and static execution environments. This thesis proposes a novel system architecture to empower cloud platforms across the whole cloud continuum with Network Acceleration as a Service (NAaaS). To provide commodity yet efficient access to acceleration, this architecture defines a layer of agnostic high-performance I/O APIs, exposed to applications and clearly separated from the heterogeneous protocols, interfaces, and hardware devices that implement it. A novel system component embodies this decoupling by offering a set of agnostic OS features to applications: memory management for zero-copy transfers, asynchronous I/O processing, and efficient packet scheduling. This thesis also explores the design space of the possible implementations of this architecture by proposing two reference middleware systems and by adopting them to support interactive use cases in the cloud continuum: a serverless platform and an Industry 4.0 scenario. A detailed discussion and a thorough performance evaluation demonstrate that the proposed architecture is suitable to enable the easy-to-use, flexible integration of modern network acceleration into next-generation cloud platforms
Distributed and synchronized measurements for the wide-area observation of electric power systems in distorted and low-inertia conditions
Get PDFWith the aim of heading towards a more sustainable future, there has been a noticeable increase in the installation of Renewable Energy Sources (RES) in power systems in the latest years. Besides the evident environmental benefits, RES pose several technological challenges in terms of scheduling, operation, and control of transmission and distribution power networks. Therefore, it raised the necessity of developing smart grids, relying on suitable distributed measurement infrastructure, for instance, based on Phasor Measurement Units (PMUs). Not only are such devices able to estimate a phasor, but they can also provide time information which is essential for real-time monitoring. This Thesis falls within this context by analyzing the uncertainty requirements of PMUs in distribution and transmission applications. Concerning the latter, the reliability of PMU measurements during severe power system events is examined, whereas for the first, typical configurations of distribution networks are studied for the development of target uncertainties. The second part of the Thesis, instead, is dedicated to the application of PMUs in low-inertia power grids. The replacement of traditional synchronous machines with inertia-less RES is progressively reducing the overall system inertia, resulting in faster and more severe events. In this scenario, PMUs may play a vital role in spite of the fact that no standard requirements nor target uncertainties are yet available. This Thesis deeply investigates PMU-based applications, by proposing a new inertia index relying only on local measurements and evaluating their reliability in low-inertia scenarios. It also develops possible uncertainty intervals based on the electrical instrumentation currently used in power systems and assesses the interoperability with other devices before and after contingency events
New insights into vaginal environment during pregnancy: a multi-omics approach
Get PDFThe present thesis aims to provide a thorough comprehension of the vaginal ecosystem of pregnant women and enhance the knowledge of pregnancy pathophysiology.
The first study emphasized the importance of limiting protein intake from animal sources, consuming carbohydrates, and avoiding starting pregnancy overweight to maintain a healthy vaginal environment characterized by lactobacilli and related metabolites.
In the second paper, a reduction in bacterial diversity, an increase in Lactobacillus abundance, and a decrease in bacterial vaginosis-related genera were observed during pregnancy. Lactobacillus abundance correlated with higher levels of lactate, sarcosine, and amino acids, while bacterial vaginosis-related genera were associated with amines, formate, acetate, alcohols, and short-chain fatty acids. An association between intrapartum antibiotic prophylaxis for Group B Streptococcus and higher vaginal abundance of Prevotella was found. Moreover, women experiencing a first-trimester miscarriage displayed a higher abundance of Fusobacterium.
The third study explored the presence of macrolides and tetracyclines resistance genes in the vaginal environment, highlighting that different vaginal microbiota types were associated with distinct resistance profiles. Lactobacilli-dominated ecosystems showed fewer or no resistance genes, while women with increased bacterial vaginosis-related genera were positive for resistance genes.
The last two papers aimed to identify potential biomarkers of vaginal health or disease status.
The fourth paper showed that positivity for Torquetenovirus decreased from the first to the third trimester, being more prevalent in women with higher vaginal leukocyte counts. Torquetenovirus-positive samples showed higher levels of cytokines, propionate, and cadaverine. Lactobacillus species decreased in Torquetenovirus-positive samples, while Sneathia and Shuttleworthia increased.
The last work pointed out the association between clade 2 of Gardnerella vaginalis and bacterial vaginosis. Moreover, as the number of simultaneously detected G. vaginalis clades increased, bacterial vaginosis-associated bacteria also tended to increase. Additionally, sialidase gene levels negatively correlated with Lactobacillus and positively correlated with Gardnerella, Atopobium, Prevotella, Megasphaera, and Sneathia
Assessment of the effects of water salinity on greenhouse gas fluxes and carbon balance in coastal wetlands
Get PDFPart I of this study gives an overlook on coastal wetlands and their role climate change mitigation, as reservoirs for organic carbon in soils. Part II investigates the impact of salinity on greenhouse gas emissions, in four wetlands along the northeast Adriatic coast. Over a year, comprehensive measurements, including soil properties, CH4 and CO2 fluxes, and water parameters, revealed a significant reduction in CH4 emissions at water heights exceeding 50 cm. Notably, temperature and irradiance strongly influenced CH4 emissions, with distinctions observed between freshwater and brackish systems. Part III delves into the relationship between microbial communities, biogeochemical processes, and potential climate-related feedbacks in temperate coastal wetlands. Addressing the dual role of these ecosystems as carbon sinks and CH4 sources, the study characterizes microbial communities using advanced sequencing techniques. Focused on three temperate wetlands along a salinity gradient, results highlight the prevalence of sulfur-reducing bacteria in salinized sites, impacting CH4 and CO2 emissions. This section underscores the need for a better understanding of wetland ecosystems, salinity effects, and climate-related feedbacks to inform conservation and climate change mitigation strategies. In Part IV, the study aims at reviewing hydrological processes and carbon dynamics in temperate wetlands. Analyzing data extracted from 50 wetlands, this section examines the interplay between environmental variables and their significant impact on CH4 budgets and carbon balances. The water column height, emerges as a critical factor influencing wetland biogeochemistry. Seasonal dynamics, including alternating inundation and drought periods, affect redox conditions, impacting CH4 generation by methanogenic bacteria. This chapter highlights some limitation of the sampling techniques used in this research. Part V resumes the finals remarks of this study. The multidisciplinary approach of this work seeks to enhance carbon storage strategies, combat climate change, and better understand the role of temperate coastal wetlands in climate change mitigation
The iuridicate of Alexandria and Egypt in the institutional system of the high Roman Empire
Get PDFLa presente dissertazione di dottorato si pone l’obiettivo di colmare una lacuna all’interno degli studi, cioè quello di realizzare un’analisi della figura istituzionale dello iuridicus Alexandreae et Aegypti, la seconda carica a livello gerarchico dell’Egitto romano, durante la fase storica dell’alto Impero. Dopo la Guida alla lettura, nella quale vengono spiegati alcuni elementi tecnici riguardanti la tesi, nell’Introduzione è proposto un résumé della letteratura precedente e una panoramica completa delle fonti che pertengono al funzionario. Il corpo vero e proprio della dissertazione è focalizzato sullo studio delle principali tematiche concernenti l’officium. Il primo capitolo è incentrato sulla questione dell’introduzione della carica all’interno della provincia, con particolare attenzione all’individuazione del periodo nel quale ciò avvenne. Il secondo capitolo è di carattere prosopografico e contiene i fasti iuridicorum, cioè un nuovo computo delle personalità che ricoprirono l’incarico, con specifico riguardo alla loro datazione. Il terzo capitolo è imperniato sull’individuazione di quel potere afferente al römisches Staatsrecht, la iuridisctio mandata, che doveva essere alla base dell’attività giurisdizionale del quadro. Il quarto capitolo indaga le principali caratteristiche della carica, ad esempio la titolatura, la possibile durata dell’incarico, l’occupazione simultanea della procuratio dell’idios logos, l’interim della dioikesis e della vice praefectura. Il quinto capitolo è finalizzato allo studio delle mansioni dello iuridicus, all’interno delle diverse sfere entro le quali si estrinsecava la sua attività, come la iurisdictio contentiosa, la iurisdictio voluntaria, lo Strafrecht e il campo dell’amministrazione. Il sesto capitolo è rivolto alla ricostruzione del dossier e del processo di Drusilla, che ha visto l’intervento di diversi iuridici. Nelle conclusioni è presente un compendio del lavoro svolto e si trovano alcune considerazioni di carattere generale riguardanti l’ufficiale. Chiude la dissertazione un’appendice concernente le attestazioni extra Aegyptum della radice δικαιοδοτ- con un significato diverso dallo iuridicato.This doctoral dissertation aims at filling a gap in the literature by carrying out an analysis of the iuridicus Alexandreae et Aegypti institutional office, the second highest-ranking position in Roman Egypt during the historical phase of the High Empire. The reading guide offers a detailed overview of the methodology that informs this study and it is followed by the introduction that summarises the pre-existing literature and provides a comprehensive overview of the sources pertaining to the office. The main body of this study delves into a detailed investigation of the officium across six chapters. The first chapter focuses on the introduction of the office within the provincia, particularly with regards to the time during which this introduction took place. The second is of prosopographic nature and includes the fasti iuridicorum, i.e. a recount of the personalities who held the office, specifically in terms of their timings. The third identifies the iuridisctio mandata as the power pertaining to the römisches Staatsrecht as well as the basis of the framework's jurisdictional activity. The fourth chapter examines the main characteristics of the office, e.g. the titling, the possible duration of the role, the simultaneous occupation of the procuratio of the idios logos, the interim of the dioikesis and vice praefectura. The fifth looks closely at the iuridicus’ duties across the different spheres within which his role was carried out, such as iurisdictio contentiosa, iurisdictio voluntaria, Strafrecht, and the field of administration. The final chapter is dedicated to the reconstruction of Drusilla's dossier and trial to which various iuridici attended. The conclusion provides a summary of the study and includes some final observations regarding the officer. An appendix that explores the extra Aegyptum attestations of the root δικαιοδοτ – with a meaning other than iuridicate – serves as this dissertation’s close