3,319 research outputs found
Portraits of Leonardo da Vinci
No full textUsing an iterative method, applied to image processing, a portrait of a young man, probably a self-portrait of Leonardo da Vinci, is restored. Merging this portrait with the self-portrait in red chalk, we can have the features of a middle-aged Leonardo. This digital portrait can be compared with the image of Plato, depicted by Raphael in the Scuola di Atene, generally considered as a portrait of Leonardo. The iterative method used for the image processing had been developed by the author on previous iterative calculations used to solve the Boltzmann equatio
Digital Signal Processing and Embedded Systems for Wireless Networked Music Performance
No full textLe nuove piattaforme per il mobile computing, introdotte alcuni anni fa hanno avuto un impatto notevole su tecnologia e società.
Due aspetti tecnici che hanno alimentato lo sviluppo del mobile computing e a loro volta sono stati alimentati da esso, sono stati la maturazione della comunità del software open-source e la disponibilità per molto produttori di silicio della proprietà intellettuale di un'architettura di calcolo molto efficiente in termini energetici. Come conseguenza dell'ampia diffusione del mobile computing, le comunità accademiche della computer music e del music computing, hanno messo a frutto le conoscenze sviluppate nell'ambito del laptop computing per portare alla fioritura di numerosi progetti di physical computing.
In questa tesi di dottorato tutti questi aspetti vengono sviluppati e studiati in maniera organica, con un interesse specifico per l'elaborazione del segnale (DSP) nello strumento musicale digitale e la performance wireless su rete. L'idea di una piattaforma di physical computing in grado di supportare il ruolo di strumento musicale e connettersi ad altri strumenti viene elaborata. Processori di segnale e algoritmi per l'industria musicale vengono analizzati da una prospettiva tecnica e storica per definire delle specifiche tecniche. Sviluppi innovativi nel DSP per la sintesi, il trattamento, il campionamento e la trasmissione del segnale sonoro sono dettagliati Lo stato dell'arte per le performance musicali in rete (NMP) viene riportato insieme alle sfide tecniche che questo impone, in modo da definire le necessità da soddisfare per una piattaforma embedded per la NMP wireless. Da questo approccio multidisciplinare scaturisce il progetto WeMUST (Wireless Music Studio), che investiga su alcune delle problematiche attualmente riscontrate ed evidenziate in precedenza e verifica la fattibilità di realizzare un sistema di NMP wireless basato su soluzioni hardware e software di largo uso.
Giunto lo sviluppo ad uno stadio soddisfacente, una prima versione del software WeMUST è stata rilasciata ed un caso d'uso è stato mostrato in pubblico nel luglio 2014 con la performance Waterfront, con musicisti su barche sulla costa di Ancona. Questa occasione di valutazione del lavoro è servita anche come riferimento per future fasi di sviluppo
Wireless networked music performance
No full textThis book presents a comprehensive overview of the state of the art in Networked Music Performance (NMP) and a historical survey of computer music networking. It introduces current technical trends in NMP and technical issues yet to be addressed. It also lists wireless communication protocols and compares these to the requirements of NMP. Practical use cases and advancements are also discussed
Ibrida: a new DWT-domain sound hybridization tool
No full textThis paper presents a new deterministic algorithm for the creative morphing or hybridization of two sounds, for use in movies and videogames sonification, experimental music composition or creative sound synthesis. The algorithm is based on DiscreteWavelet Transform (DWT) filter banks, for sound decomposition, and one IDWT filter bank where a mix of the DWT coefficients streams is transformed back in the time domain for output. The use of the DWT for this purpose proves more computationally efficient than stochastic methods while more perceptually oriented than DFT because of its nonuniform time-frequency decomposition and introduces less control parameters. The addition of an onset detection algorithm in the wavelet domain helps creating dynamic morphing. A Pure Data implementation of the algorithm has been performed to investigate the problem of controlling the morphing parameters with physical interfaces such as touch sensitive screens
Towards a Sustainable Internet of Sounds
No full textThe Internet of Sounds (IoS) is an emerging research area at the intersection of engineering fields and humanities including computing, communication technology, audio signal processing, acoustic monitoring, music and arts. Although this research field is expected to have beneficial impacts on society through entertainment, creativity, well-being, monitoring and security, it is paramount to be aware of the adverse impact of current technology on the environment in terms of greenhouse gases emissions, pollution and soil consumption. In this study we provide a survey of the environmental issues produced by current information and communication technology (ICT) and relate these to the use cases that the IoS envisions. On the basis of this survey, we identify some key aspects to reduce the footprint of IoS services and products and then we provide suggestions to make advancements in IoS environment-aware
Totally Asymmetric Limit for Models of Heat Conduction
No full textWe consider one dimensional weakly asymmetric boundary driven models of heat
conduction. In the cases of a constant diffusion coefficient and of a quadratic mobility we
compute the quasi-potential that is a non local functional obtained by the solution of a
variational problem. This is done using the dynamic variational approach of the macroscopic
fluctuation theory (Bertini et al. in Rev Mod Phys 87:593, 2015). The case of a concave
mobility corresponds essentially to the exclusion model that has been discussed in Bertini
et al. (J Stat Mech L11001, 2010; Pure Appl Math 64(5):649–696, 2011; Commun Math
Phys 289(1):311–334, 2009) and Enaud and Derrida (J Stat Phys 114:537–562, 2004). We
consider here the convex case that includes for example the Kipnis-Marchioro-Presutti (KMP)
model and its dual (KMPd) (Kipnis et al. in J Stat Phys 27:6574, 1982). This extends to the
weakly asymmetric regime the computations in Bertini et al. (J Stat Phys 121(5/6):843–
885, 2005). We consider then, both microscopically and macroscopically, the limit of large
externalfields. Microscopically we discuss some possible totally asymmetric limits of the
KMP model. In one case the totally asymmetric dynamics has a product invariant measure.
Another possible limit dynamics has instead a non trivial invariant measure for which we
give a duality representation. Macroscopically we show that the quasi-potentials of KMP
and KMPd, which are non local for any value of the external field, become local in the limit.
Moreover the dependence on one of the external reservoirs disappears. For models having
strictly positive quadratic mobilities we obtain instead in the limit a non local functional
having a structure similar to the one of the boundary driven asymmetric exclusion process
Gibbsian Stationary Non-equilibrium States
No full textWe study the structure of stationary non-equilibrium states for interacting particle
systems from a microscopic viewpoint. In particular we discuss two different discrete
geometric constructions. We apply both of them to determine non reversible transition rates
corresponding to a fixed invariant measure. The first one uses the equivalence of this problem
with the construction of divergence free flows on the transition graph. Since divergence
free flows are characterized by cyclic decompositions we can generate families of models
from elementary cycles on the configuration space. The second construction is a functional
discrete Hodge decomposition for translational covariant discrete vector fields. According to
this, for example, the instantaneous current of any interacting particle system on a finite torus
can be canonically decomposed in a gradient part, a circulation term and an harmonic component.
All the three components are associated with functions on the configuration space.
This decomposition is unique and constructive. The stationary condition can be interpreted
as an orthogonality condition with respect to an harmonic discrete vector field and we use
this decomposition to construct models having a fixed invariant measur
Introduzione. «Arti di pinna»: Leonardo Sciascia Saggista
No full textThe article presents the main theme of the XIV Sciascia Colloquium - the essay form explored by Leonardo Sciascia in his works - discussing each contribution and the focus each author chose to develop for this volume publication
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