Coordinated Control of Robotic Swarms in Unknown Environments

This thesis gathers the work carried out by the author in the last three years of research and it concerns the study and implementation of algorithms to coordinate and control a swarm of mobile robots moving in unknown environments. In particular, the author's attention is focused on two different approaches in order to solve two different problems. The first algorithm considered in this work deals with the possibility of decomposing a main complex task in many simple subtasks by exploiting the decentralized implementation of the so called \emph{Null Space Behavioral} paradigm. This approach to the problem of merging different subtasks with assigned priority is slightly modified in order to handle critical situations that can be detected when robots are moving through an unknown environment. In fact, issues can occur when one or more robots got stuck in local minima: a smart strategy to avoid deadlock situations is provided by the author and the algorithm is validated by simulative analysis. The second problem deals with the use of concepts borrowed from \emph{graph theory} to control a group differential wheel robots by exploiting the Laplacian solution of the consensus problem. Constraints on the swarm communication topology have been introduced by the use of a range and bearing platform developed at the Distributed Intelligent Systems and Algorithms Laboratory (DISAL), EPFL (Lausanne, CH) where part of author's work has been carried out. The control algorithm is validated by demonstration and simulation analysis and, later, is performed by a team of four robots engaged in a formation mission. To conclude, the capabilities of the algorithm based on the local solution of the consensus problem for differential wheel robots are demonstrated with an application scenario, where nine robots are engaged in a hunting task.

Unveiling the unknown of cool stars with high-resolution spectroscopy

Cool giant and supergiant stars are among the brightest populations in any stellar system and they are easily observable out to large distances, especially at infrared wavelengths. These stars also dominate the integrated light of star clusters in a wide range of ages, making them powerful tracers of stellar populations in more distant galaxies. High-resolution near-IR spectroscopy is a key tool for quantitatively investigating their kinematic, evolutionary and chemical properties. However, the systematic exploration and calibration of the NIR spectral diagnostics to study these cool stellar populations based on high-resolution spectroscopy is still in its pioneering stage. Any effort to make progress in the field is innovative and of impact on stellar archaeology and stellar evolution. This PhD project takes the challenge of exploring that new parameter space and characterizing the physical properties, the chemical content and the kinematics of cool giants and supergiants in selected disc fields and clusters of our Galaxy, with the ultimate goal of tracing their past and recent star formation and chemical enrichment history. By using optical HARPS-N and near-infrared GIANO-B high-resolution stellar spectra in the context of the large program SPA-Stellar Population Astrophysics: the detailed, age-resolved chemistry of the Milky Way disk” (PI L. Origlia), an extensive study of Arcturus, a standard calibrator for red giant stars, has been performed. New diagnostics of stellar parameters as well as optimal linelists for chemical analysis have been provided. Then, such diagnostics have been used to determine evolutionary properties, detailed chemical abundances of almost 30 different elements and mixing processes of a homogeneous sample of red supergiant stars in the Perseus complex.

Audience attitudes towards simil sync: a pilot study

This thesis is based on a pilot investigation which explores the attitudes of a sample of Italian viewers towards the simil sync technique which in Italy is used for the dub of non-fictional television contents. The thesis seeks to analyse and define the characteristics of this dubbing modality which is often considered by scholars and professionals in the dubbing industry a hybrid modality of standard synchronised dubbing and voice-over. In order to investigate viewers’ attitudes, I organised 4 focus groups sessions which, due to the impact of Covid-19 pandemic, were carried out online. The online recruitment of participants, which was a difficult task, resulted in a small sample of eighteen participants (and two interviewees). The four online focus groups revealed that participants were aware of the simil sync technique. They recognised that the clips were dubbed in a different modality from standard synchronised dubbing. The characteristic that was mostly mentioned for detecting simil sync was the original soundtrack that was audible below the dub, followed by the identification of the genre of the programme in the clip and the absence of lip sync. Moreover, while simil sync with a barely audible original soundtrack received neutral or positive attitudes, simil sync with a more audible original soundtrack, instead, was tolerated or considered annoying. Simil sync passed unnoticed in the in-depth interviews in which the discussion about dubbing was not focused on the distinction between two dubbing modalities, for instance simil sync versus standard synchronised dubbing, but rather on the distinction between programmes that originated in Italian and those that were translated into Italian from another language and then dubbed.

I festival culturali come strumento di creazione di cittadinanza attiva: il caso di Arona Citta Teatro

DOMANDA DI RICERCA La cultura comprende il patrimonio collettivo materiale e immateriale, sia come frutto di pensiero e speculazione, sia come insieme di pratiche, compresi i festival. Con la loro ritualità e creazione di identità collettiva, i festival culturali hanno un impatto sociale, culturale ed economico sul territorio e sui cittadini coinvolti. Ma in che modo festival culturali, seppur con la loro temporaneità, contribuiscono alla creazione di cittadinanza attiva? TEORIE DI RIFERIMENTO La ricerca si inserisce nella crescente attenzione ai festival culturali nell'ambito degli Event Studies che approfondiscono le questioni relative a eventi e manifestazioni, compresi i festival. Allo scopo di comprendere se i festival siano dispositivi della crescita del benessere del territorio, si calerà il dibattito all’interno delle riflessioni sui temi dell’audience development e del welfare culturale. METODOLOGIA Il festival caso studio per la ricerca, seguendo alcuni criteri selettivi, è stato individuato come Teatro sull'Acqua, festival nato ad Arona nel 2011 diretto da Dacia Maraini. Il caso studio è stato analizzato in oltre un anno di osservazione (aprile 2021 - settembre 2022), con un approccio mixed method, combinano ricerca qualitativa e quantitativa, ovvero si sono effettuate l’osservazione partecipante; interviste semi-strutturata; quattro questionari. RISULTATI Tra i risultati raggiunti c'è l'individuazione delle tipologie di audience del festival analizzato. Il campione di riferimento restituisce l'immagine di un pubblico prevalentemente femminile, maturo, con un alto livello di istruzione, locale e appartenente a un ceto medio. Un pubblico fidelizzato e fortemente partecipe alle pratiche culturali, per i quali il festival diventa un momento relazione, di condivisione esperienziale e sociale. Il festival ha un forte impatto sulla comunità e ha avvicinato a materie culturali prima sconosciuti, incentivando la fruizione a nuove attività culturali.

Cancers of unknown primary site (CUPs) as a model of metastatic process.

Cancers of unknown primary site (CUPs) are a rare group of metastatic tumours, with a frequency of 3-5%, with an overall survival of 6-10 month. The identification of tumour primary site is usually reached by a combination of diagnostic investigations and immunohistochemical testing of the tumour tissue. In CUP patients, these investigations are inconclusive. Since international guidelines for treatment are based on primary site indication, CUP treatment requires a blind approach. As a consequence, CUPs are usually empiric treated with poorly effective. In this study, we applied a set of microRNAs using EvaGreen-based Droplet Digital PCR in a retrospective and prospective collection of formalin-fixed paraffin-embedded tissue samples. We assessed miRNA expression of 155 samples including primary tumours (N=94), metastases of known origin (N=10) and metastases of unknown origin (N=50). Then, we applied the shrunken centroids predictive algorithm to obtain the CUP’s site(s)-of-origin. The molecular test was successfully applied to all CUP samples and provided a site-of-origin identification for all samples, potentially within a one-week time frame from sample inclusion. In the second part of the study we derived two CUP cell lines, and corresponding patient-derived xenografts (PDXs). CUP cell lines and PDXs underwent histological, molecular, and genomic characterization confirming the features of the original tumour. Tissues-of-origin prediction was obtained from the tumour microRNA expression profile and confirmed by single cell RNA sequencing. Genomic testing analysis identified FGFR2 amplification in both models. Drug-screening assays were performed to test the activity of FGFR2-targeting drug and the combination treatment with the MEK inhibitor trametinib, which proved to be synergic and exceptionally active, both in vitro and in vivo. In conclusion, our study demonstrated that miRNA expression profiling could be employed as diagnostic test. Then we successfully derived two CUP models from patients, used for therapy tests, bringing personalized therapy closer to CUP patients.