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<p>The two primarily methodologies discussed in this thesis are the nonparametric entropy-based synthetic timeseries (NEST) and Directed infusion of data (DIOD) algorithms. </p> <p><br></p> <p>The former presents a novel synthetic data algorithm that is shown to outperform sismilar state-of-the-art, including generative networks, in terms of utility and data consistency. Majority of data used are open-source, and are cited where appropriate.</p> <p><br></p> <p>DIOD presents a novel data masking paradigm that presevres the utility, privacy, and efficiency required by the current industrial paradigm, and presents a cheaper alternative to many state-of-the-art. Data used include simulation data (source code cited), equations-based data, and open-source images (cited as needed). </p>

[pt] O som e o silêncio, como elementos constitutivos do cinema, têm sido atravessados por diferentes mudanças tecnológicas no decorrer de sua história. Cada modificação alterou de certa forma os seus modos de realização e de escuta, transformando também as próprias estruturas da indústria cinematográfica. Atualmente, devido à passagem da tecnologia analógica para a digital, características como: o considerável aumento de faixas de áudio para captura e edição simultânea, maior facilidade na manipulação das ondas sonoras capturadas, o desenvolvimento eletroacústico das salas de cinema e sistemas de produção particular, entre outros, sugerem a impressão de um incremento sensitivo nas produções cinematográficas recentes, revelando uma notoriedade acentuada nos ruídos e, principalmente, no silêncio e em seu potencial efeito dramático. O objetivo desta pesquisa é, portanto, analisar as diferentes propriedades que pode presentar o silêncio como efeito sonoro dentro do cinema contemporâneo brasileiro e colombiano. O estudo deste fenômeno acústico, como elemento da linguagem cinematográfica, estará baseado em pesquisas anteriores sobre o som e o silêncio no audiovisual e em produções realizadas principalmente no século XXI, procurando reflexionar sobre o silêncio no cinema dentro da era digital. / [en] Sound and silence, as constituent elements of cinema, have been crossed by diferent technological changes throughout its history. Each modification has altered its ways of realization and listening to some extent, also transforming the very structures of the film industry. Currently, due to the transition from analogue to digital technology, features such as: the considerable increase in audio tracks for simultaneous capture and editing, greater ease in handling captures sound waves, the electroacoustic development of movie theaters and private productions systems, among others, they suggest the impression of a sensory increase in recent cinematographic productions, revealing a marked notoriety in noise and, mainly, in silence and its potential dramatic effect. The objective of this research is, therefore, to analyze the different properties that silence can present as a sound effect within contemporary Brazilian and Colombian cinema. The study of this acoustic phenomenon, as an element of cinematographic language, will be based on previous research on sound and silence in audiovisual and on productions executed mainly in the 21st century, seeking to reflect on silence in cinema within the digital age.

One of the key security aspects which must be evaluated for cryptosystems is their resistance against side-channel attacks. Masking is a commonly used countermeasure against side-channel attacks, in which the secret to be protected is partitioned into multiple shares using random “masks”. A k-order masked implementation uses k+1 shares. Masked implementations are available for the key encapsulation mechanism of Saber, a finalist in the NIST post-quantum cryptography standardization project. Though Saber has not been selected for standardization, it is similar to the selected CRYSTALS-Kyber, and may therefore have similar leakage. In this thesis, a side-channel attack against a higher-order masked implementation of Saber is attempted. A previous attack on first-order masked Saber using a deep learning-based approach is used as a starting point, though differences in the implementations make the attack not directly applicable to the higher-order case. A byte-wise leakage is found in the higher-order masked implementation, and two different attacks on this leakage point are considered. The first uses the Hamming weights of bytes and is able to recover Hamming weights of individual shares but not the complete message or secret keys from 2nd-order masked Saber. The other uses a method from a different previous side-channel attack in which message bytes are recovered using biased deep learning models. This method successfully recovers all message bytes from 1st-order masked Saber and is shown to successfully recover byte values from 2nd-order masked Saber by training multiple biased models and selecting the best performing models from these, though this also requires a much larger amount of attack data than the 1st-order masking case. This shows that a bytewise leakage in higher-order masked Saber can be exploited using a power analysis side-channel attack, though recovering the complete message and secret keys remains as future work. / En av de främsta säkerhetsaspekterna som måste utvärderas för krypteringsalgoritmer är resistens mot sidokanalsattacker. Maskning är en av de vanligaste åtgärderna för att skydda mot sidokanalsattacker, där känslig information partitioneras i flera delar med hjälp av slumpmässiga värden. En maskning av ordning k använder k+1 delar. Maskade implementationer finns tillgängliga för Saber, en av finalisterna NISTs postkvantkryptografiska standardiseringsprojekt. Saber har inte valts som standard, men har många likheter med den valda standarden CRYSTALS-Kyber och kan därför ha liknande sårbarheter. I detta examensarbete utförs en sidokanalsattack på en högre ordnings maskad implementation av Saber. En tidigare attack på första ordningens maskad Saber används som utgångspunkt, men skillnader i implementationen gör att denna attack inte kan användas direkt. Ett läckage på byte-nivå hittads i den högre ordnings maskade implementationen, och två olika attacker utförs. Den första, som använder Hammingvikten av en byte i meddelandet, kunde erhålla Hammingvikterna för individuella delar av det maskade meddelandet, men inte det ursprungliga meddelandet. Den andra attacken använder en metod från en tidigare sidokanalsattack där meddelanden kunde erhållas med hjälp av partiska djupinlärningsmodeller. Den här metoded kunde användas för att erhålla alla bytevärden från meddelandet med fösta ordningens maskning. Med betydligt mer data och genom att träna ett flertal djupinlärningsmodeller och sedan välja de bästa från bland dessa kunda även vissa bytevärden erhållas från andra ordningens maskning. Detta visar att denna svaghet på byte-nivå kan användas vid en attack på högre ordnings maskad Saber, men det återstår att extrahera hela meddelandet och hemliga nycklar.

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This paper handles the background theory, methods and results of the master thesis project titled "Variable acoustics in multi-functional stadiums". \\ The purpose of the project was to investigate whether variable room acoustics could be applicable to large multi-functional stadiums to improve their ability to adapt the soundscape in the stadium for different types of events. The two events which were analyzed during the project was electrically amplified concerts and ice hockey matches. \\ The paper starts by going over relevant acoustical and psycho-acoustical parameters and concepts as well as giving a few examples on already existing multi-functional stadiums including their acoustical strengths and weaknesses towards the two types of events. The report concludes that reflections are of the utmost importance for both types of events, especially early-arriving reflection with great magnitudes. At concerts, these are wished to be repressed while at hockey-matches, the early reflections should be amplified and increased in quantity to give the crowd a better feedback from the stadium increasing the supporters ability to create a loud and intense atmosphere. \\ Gallon fabric, aluminum and plexi-glass was tested in the MWL-laboratory in order to assess the materials reflective capabilities as the idea was to use these materials as reflectors during the hockey-matches. The results showed close to full reflection across the entire spectrum for aluminum and plexi-glass while the gallon fabric showed great reflective capabilities for the higher frequencies while letting the lower frequencies pass through the material. \\ The effects off the reflectors on the soundscape was simulated in a fictional stadium which was built in the modelling software SketchUp using the simulation software ODEON. The results showed great promise as the reflectors gave a great increase in the early reflections. As for the concerts, rolling-curtains which can easily be mounted and removed was added around the walls of the stadium while the reflectors was removed. This solution also showed great results during the simulations as the early reflections was now suppressed instead of magnified. / Denna uppsats behandlar bekgrundsteori, metodik och resultat från examensarbetet titulerat "Variabel rumsakustik i multi-funktions arenor".\\ Syftet med projektet var att undersöka huruvida variabel rumsakustik skulle kunna tillämpas på stora multi-funktions arenor för att förbättra dess förmåga att anpass sin ljudbild för olika typer av evenemang. Projektet riktar sig mot elförstärkta konserter och ishockey-matcher. \\ Uppsatsen börjar med att gå igenom relevanta akustiska och psyko-akustiska parametrar och begrepp för att sedan ge några exempel på redan existerande multi-funktions arenors akustiska styrkor och svagheter vid de bägge typerna av evenemang. Rapporten drar slutsatsen att reflektioner är av yttersta vikt vid bägge fallen, särkiljt de som är tidigt anländande och av hög magnitud. Under konserter önskas dessa att dämpas medans man vid ishockey-matcher önskar att förstärka dessa och öka dess antal för att ge publiken en starkare akustisk återkoppling från arenan och underlätta för supportrarna att skapa en högljudd och intensiv atmosfär. \\ Galonstyg, aluminium och plexiglas testades i MWL-laboratoriet för att bedöma dess reflekterande förmågor då idén var att använda dessa material som reflektorer under ishockey-matcherna. Resultaten visade nära full reflektion över hela spektrat för de aluminiumet och plexi-glaset medan galonstyget visade stora reflketerande egenskaper vid högre frekvenser samtidigt som det tillät de lägre frekvenserna passera genom materialet. \\ Reflektorernas effekt på ljudbilden simulerades i en påhittat arena som byggdes i moddeleringsprogrammet SketchUp med hjälp av simuleringsprogrammet ODEON. Resultaten var mycket lovande då en stor ökning sågs hos de tidiga reflexerna, både i kvantitet och kvalitet. För konserterna användes istället ljudabsorberande rullgardiner längs arenans väggar medans reflektorerna togs bort. Simuleringsresultaten visade nu istället en markant minsking i tidiga reflexer.

H διδακτορική διατριβή μελετά ζητήματα που αφορούν την ενσωμάτωση υπολογιστικών μοντέλων ακοής για την μοντελοποίηση και επεξεργασία ηχητικών σηματών για την βέλτιστη αναπαραγωγή τους σε χώρους με αντήχηση καθώς και την κωδικοποίηση ηχητικών δεδομένων. Το κύριο μέρος της διατριβής επικεντρώθηκε στην μοντελοποίηση των αντιληπτικά σημαντικών αλλοιώσεων λόγω αντήχησης, με την βοήθεια κατάλληλα οριζόμενων μόνο-ωτικών και διαφορικών ενδο-καναλικών παραμέτρων και την απεικόνιση τους με τη βοήθεια χρονο-συχνοτικών 2Δ αναπαραστάσεων. Ο λεπτομερής εντοπισμός των αλλοιώσεων στα ηχητικά σήματα μέσω του προτεινόμενου Δείκτη Επικάλυψης λόγω Αντήχησης (ΔΕΑ) διαμόρφωσε κατάλληλη μεθοδολογία ανάλυσης-σύνθεσης, για την καταστολή της αντήχησης σε συγκεκριμένες χρονο-συχνοτικές περιοχές. Το κύριο πλεονέκτημα της προτεινόμενης, εξαρτώμενης του σήματος, μεθοδολογίας είναι ότι επιτυγχάνεται η καταστολή των, με σχετική καθυστέρηση, παραμορφώσεων λόγω αντήχησης σε μια μεγαλύτερη κλίμακα, δεδομένου ότι μόνο οι αντιληπτικά σημαντικές περιοχές του σήματος επηρεάζονται από την επεξεργασία. Επιπλέον, αναζητήθηκε η δυνατότητα ανάλυσης των ηχητικών δεδομένων με βάση τις εσωτερικές τους αναπαραστάσεις (όπως δηλαδή τις παρέχει το υπολογιστικό μοντέλο ακοής) με εφαρμογή στην περιοχή της κωδικοποίησης σημάτων. Ο προτεινόμενος μη-ομοιόμορφος κβαντιστής πραγματοποιεί τη διαδικασία της κβάντισης χρονο-συχνοτικά με κατάλληλη οδήγηση από το υπολογιστικό μοντέλο ακοής, εξασφαλίζοντας καλύτερη υποκειμενική ηχητική ποιότητα, σε σχέση με ένα ομοιόμορφο PCM κβαντιστή. Χρησιμοποιώντας τη βασική λειτουργία του μη-ομοιόμορφου κβαντιστή, υλοποιήθηκε ενά κριτήριο αξιολόγησης ηχητικών δεδομένων, όπου σε αντίθεση με καθιερώμενα κριτήρια (όπως το Noise to Mask Ration, NMR) επιτελεί τις λειτουργίες του στο πεδίο χρόνου-συχνότητας και παρέχει τη δυνατότητα εντοπισμού της υποκειμενικά σημαντικής παραμόρφωσης με βάση την χρονική εξέλιξη του σήματος. / The dissertation studies issues concerning the integration of computational auditory models for modeling and processing of audio signals for optimal reproduction in reverberant spaces as well as topics related to audio coding. Based on the theoretical framework analysis that was established, the necessity of a signal-dependent approach was underlined for modeling the perceptually-relevant effects of reverberation. The main part of the dissertation thesis was focused on describing the perceptually-relevant alterations due to reverberation, based on appropriate defined monaural and differential inter-channel parameters and also their representation with well-defined time-frequency 2D maps. The detailed localization of alterations due to reverberation in the acoustic signals via the proposed Reverberation Masking Index (RMI) introduced an analysis-synthesis methodology for the compensation of reverberation in perceptually-significant time-frequency regions incorporating also, well-established digital signal processing techniques. The main advantage of the proposed signal-dependent methodology is that the suppression of reverberant tails can be achieved on a larger scale under practical conditions, since only perceptually significant regions of the signal are affected after processing. Additionally, the proposed framework complements the more traditional system-dependent inverse filtering methods, enabling novel and efficient signal processing schemes to evolve for room dereverberation applications. The thesis examines also the feasibility of the acoustic signal analysis based on the internal representations provided by the computational auditory model, applicable in the area of audio coding. The proposed non-uniform quantizer operates in the time-frequency domain, where a novel quantization process is driven by the computational auditory model, thus enabling an overall better perceptual quality with respect to uniform PCM quantizer. Considering the fundamental operation of the novel non-uniform quantizer, a criterion for audio quality evaluation was proposed, where contrary to well-established criteria (i.e., Noise to Mask Ratio, NMR) its potential structure performs in the time-frequency domain and provides the detailed localization of perceptually-important distortions based on the input signal’s evolution.

<pre><p>Difficulty understanding speech in background noise is the most common hearing complaint. Elucidating the neurophysiological mechanisms underlying speech intelligibility in everyday environments with multiple sound sources and distortions is hence important for any technology that aims to improve real-world listening. Using a combination of behavioral, electroencephalography (EEG), and computational modeling experiments, this dissertation provides insight into how the brain analyzes such complex scenes, and what roles different acoustic cues play in facilitating this process and in conveying phonetic content. Experiment #1 showed that brain oscillations selectively track the temporal envelopes (i.e., modulations) of attended speech in a mixture of competing talkers, and that the strength and pattern of this attention effect differs between individuals. Experiment #2 showed that the fidelity of neural tracking of attended-speech envelopes is strongly shaped by the modulations in interfering sounds as well as the temporal fine structure (TFS) conveyed by the cochlea, and predicts speech intelligibility in diverse listening environments. Results from Experiments #1 and #2 support the theory that temporal coherence of sound elements across envelopes and/or TFS shapes scene analysis and speech intelligibility. Experiment #3 tested this theory further by measuring and computationally modeling consonant categorization behavior in a range of background noises and distortions. We found that a physiologically plausible model that incorporated temporal-coherence effects predicted consonant confusions better than conventional speech-intelligibility models, providing independent evidence that temporal coherence influences scene analysis. Finally, results from Experiment #3 also showed that TFS is used to extract speech content (voicing) for consonant categorization even when intact envelope cues are available. Together, the novel insights provided by our results can guide future models of speech intelligibility and scene analysis, clinical diagnostics, improved assistive listening devices, and other audio technologies.</p></pre>

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