172,186 research outputs found
Alla riscoperta dei «Tesori musicali emiliani»
No full text«Tesori musicali emiliani» è una collana di edizioni critiche di musiche del Sei-Settecento che presentano grande interesse storico, stilistico ed esecutivo, e dovute a compositori emiliani per nascita o per adozione. L’iniziativa ha preso vita nel 2008, quando l’editore UtOrpheus ha accolto con favore un progetto a firma di Francesco Lora ed Elisabetta Pasquini
La ricerca pedagogico-musicale del Dipartimento delle Arti e del "Saggiatore musicale"
No full textLa ricerca scientifica in Pedagogia e Didattica della musica del Dipartimento delle Arti e del «Saggiatore musicale» si sviluppa su due fronti: la ricerca pura, teorica e metodologica, sui processi d’insegnamento e apprendimento della musica, e la ricerca applicata, che consiste nella declinazione degli esiti della ricerca pura sul terreno di un fitto, denso e intenso lavoro interistituzionale – chi si occupa di Pedagogia non può non confrontarsi in modo diretto con la società – nonché nell’organizzazione di svariate attività
Eigenvalue patterned condition numbers: Toeplitz and Hankel cases
No full textWe continue the study started in [Noschese and Pasquini, Eigenvalue condition numbers: zero-structured versus traditional. J. Comput. Appl. Math. 185 (2006) 174-189] concerning the sensitivity of simple eigenvalues of a matrix A to perturbations in A that belong to a chosen subspace of matrices. In [Noschese and Pasquini, Eigenvalue condition numbers: zero-structured versus traditional. J. Comput. Appl. Math. 185 (2006) 174-189] the zero-structured perturbations have been considered. Here we focus on patterned perturbations, and the cases of the Toeplitz and of the Hankel matrices are investigated in detail. Useful expressions of the absolute patterned condition number of the eigenvalue lambda and of the analogue of the matrix yx(H), which leads to the traditional condition number of)., are given. MATLAB codes are defined to compare traditional, zero-structured and patterned condition numbers. A report on significant numerical tests is included. (C) 2006 Elsevier B.V. All rights reserved
Statistical and deterministic approaches for multimedia forensics
No full textThe increasing availability and pervasiveness of multimedia data in our society is before our very eyes.
As a result of globalization and worldwide connectivity, people from all over the planet are exchanging constantly increasing amounts of images, videos, audio recordings on a daily basis. Coupled with the easy access to user-friendly editing software, this poses a number of problems related to the reliability and trustworthiness of such content, as well as its potential malevolent use. For this reason, the research field of multimedia forensics focuses on the development of forensic tools for verifying the authenticity of multimedia data. The hypothesis of pristine status of images, videos or audio tracks is called into question and can be rejected if traces of manipulation are detected with a certain degree of confidence. In this framework, studying traces left by any operation that could have been employed to process the data, either for malicious purposes or simply to improve their content or presentation, turns out to be of interest for a comprehensive forensic analysis.
The goal of this doctoral study is to contribute to the field of multimedia forensics by exploiting intrinsic statistical and deterministic properties of multimedia data.
With this respect, much work has been devoted to the study of JPEG compression traces in digital images, resulting in the development of several innovative approaches. Indeed, some of the main related research problems have been addressed and solution based on statistical properties of digital images have been proposed. In particular, the problem of identifying traces of JPEG compressions in images that have been decompressed and saved in uncompressed formats has been extensively studied, resulting in the design of novel statistical detectors. Given the enormous practical relevance, digital images in JPEG formats have also been considered. A novel method aimed at discriminating images compressed only once and more than once has been developed, and tested on a variety of images and forensic scenarios. Being the potential presence of intelligent counterfeiters ever increasingly studied, innovative counterforensic techniques to JPEG compression based on smart reconstruction strategies are proposed.
Finally, we explore the possibility of defining and exploiting deterministic properties related to a certain processing operation in the forensic analysis. With this respect, we present a first approach targeted to the detection in one-dimensional data of a common data smoothing operation, the median filter. A peculiarity of this method is the ability of providing a deterministic response on the presence of median filtering traces in the data under investigation
Studi e Problemi di Critica Testuale
No full textFondati da Raffaele Spongano nel 1970 e da lui diretti fino al 1995, gli «Studi e problemi di critica testuale» (ISSN: 0049-2361) sono poi passati sotto la direzione di Emilio Pasquini, cui nel 2001 si sono affiancati altri tre allievi di Spongano, Alfredo Cottignoli, Clemente Mazzotta e Vittorio Roda, nonché una redazione di giovani studiosi afferenti al Dipartimento di Italianistica dell’Università di Bologna. La rivista, semestrale, si ispira a un'idea modernamente complessa di filologia, non ristretta al puro aspetto ecdotico, ma inclusiva di tutto ciò che concerne l'esegesi dei testi letterari e la loro collocazione nel loro contesto storico e in un più vasto reticolato intertestuale. Assai ricca la sezione delle recensioni e rassegne; di grande utilità quella degli spogli da periodici italiani e stranieri.
E' una delle 5 riviste di italianistica italiane incluse nel Citation Index dell'ISI
Hadron Tomography through Wigner Distributions
No full textWe study the Wigner functions of the nucleon which provide multidimensional images of the quark distributions in phase space and combine in a single picture all the information contained in the generalized parton distributions (GPDs) and the transverse-momentum dependent parton distributions (TMDs). In particular, we present results for the distribution of unpolarized quarks in a longitudinally polarized nucleon obtained in a light-cone constituent quark model. Treating the Wigner distribution as it was a classical distribution, we obtain the quark orbital angular momentum and compare it with alternative definitions given in terms of the GPDs and the TMDs
Effective localization induced by noise and nonlinearity
No full textBlanchard P, Pasquini M, Serva M. Effective localization induced by noise and nonlinearity. PHYSICA D. 2000;141(3-4):214-220.With the aid of a very simple model with only two possible configurations, we study the dynamical transition from delocalized to localized states for quantum bistable systems. Results may have relevance for the understanding of the phenomenology of some mesoscopic systems which are usually found in a localized state as for example pyramidal AsH3 molecule. The interaction with the environment is modeled by considering bath external noise disturbance and nonlinear effects due to the contraction of the Hilbert space. The noise alone produces decoherence and suppression of tunneling, but delocalized states spontaneously evolve into localized ones only when nonlinearity is also present. (C) 2000 Elsevier Science B.V. All rights reserved
On the Origin of Model Relations among Transverse-Momentum Dependent Parton Distributions
No full textpeer reviewedTransverse-momentum dependent parton distributions (TMDs) are studied in the framework of quark models. In particular, quark-model relations among TMDs are reviewed, elucidating their physical origin in terms of the quark-spin structure in the nucleon. The formal aspects of the derivation of these relations are complemented with explicit examples, emphasizing how and to which extent the conditions which lead to relations among TMDs are implemented in different classes of quark models
Quark Wigner Distributions and Orbital Angular Momentum
No full textpeer reviewedWe study the Wigner functions of the nucleon which provide multidimensional images of the quark distributions in phase space. These functions can be obtained through a Fourier transform in the transverse space of the generalized transverse-momentum dependent parton distributions. They depend on both the transverse position and the three-momentum of the quark relative to the nucleon, and therefore combine in a single picture all the information contained in the generalized parton distributions and the transverse-momentum dependent parton distributions. We focus the discussion on the distributions of unpolarized/longitudinally polarized quark in an unpolarized/longitudinally polarized nucleon. In this way, we can study the role of the orbital angular momentum of the quark in shaping the nucleon and its correlations with the quark and nucleon polarizations. The quark orbital angular momentum is also calculated from its phase-space average weighted with the Wigner distribution of unpolarized quarks in a longitudinally polarized nucleon. The corresponding results obtained within different light-cone quark models are compared with alternative definitions of the quark orbital angular momentum, as given in terms of generalized parton distributions and transverse-momentum dependent parton distributions
Information-theoretic bounds of resampling forensics: New evidence for traces beyond cyclostationarity
No full textAlthough several methods have been proposed for the detection of resampling operations in multimedia signals and the estimation of the resampling factor, the fundamental limits for this forensic task leave open research questions. In this work, we explore the effects that a downsampling operation introduces in the statistics of a 1D signal as a function of the parameters used. We quantify the statistical distance between an original signal and its downsampled version by means of the Kullback-Leibler Divergence (KLD) in case of a wide-sense stationary 1st-order autoregressive signal model. Values of the KLD are derived for different signal parameters, resampling factors and interpolation kernels, thus predicting the achievable hypothesis distinguishability in each case. Our analysis reveals unexpected detectability in case of strong downsampling due to the local correlation structure of the original signal. Moreover, since existing detection methods generally leverage the cyclostationarity of resampled signals, we also address the case where the autocovariance values are estimated directly by means of the sample autocovariance from the signal under investigation. Under the considered assumptions, the Wishart distribution models the sample covariance matrix of a signal segment and the KLD under different hypotheses is derived
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