181 research outputs found
Un'«esperienza etimologica»: romanesco antico "peta"
No full textThe author proposes to bring the Old Abruzzese and Old Romanesco word "peta" back to a Longobard base «baida/paita», which survives in the Rhaeto-romance "peda" ‘Zeit, Weile’, a word he encountered by chance in an Engadinian translation dated 1560. The relative «etymological experience» confirms the teaching of G. Contini, according to which good etymologies are found, not sought for
Forme verbali doppie negli antichi volgari italiani. Frammenti di una «Stellungsregel» italoromanza
No full textThe author analyses a number of multiple verbal forms that characterise many
ancient and modern Italian dialects in terms of an original opposition between
clitic and tonic forms, an opposition which seems to be reflected in the relative
position preference found in medieval texts
Una lettera mercantile in volgare romanesco della fine del Trecento
No full textThe author publishes a letter written by the Roman merchant Iacobello dei Cosciari
and addressed in Genua to the captain of a Ligurian ship carrying a cargo
of grain that could not be unloaded in the port of Rome owing to a setback.
This text, together with other related letters published here, gives an idea of the
workings of the merchants’ postal system of the late Middle Ages, ensuring the
rapid diffusion of news of commercial interest. From a linguistic and philological
perspective, Iacobello’s letter is a very rare, indeed unique, example of direct
merchant writing from 14th century Rome
Disposizioni testamentarie in volgare padovano d'età carrarese
No full textThe article publishes a private text (1386) that contains the last wishes written in the vernacular by an important member of the Paduan nobility at the time of the Carrarese lordship. The text then served as a model for the notary who drew up the real will in the universal language of law, namely Latin. The vernacular document presents many aspects of interest to historians of language, palaeographers, historians of law and historians of the Italian Middle Ages. The author seeks to highlight its multifaceted nature, making it an exemplary case of interdisciplinary study
Learning-based hierarchical control of water reservoir systems
No full textThe optimal control of a water reservoir system represents a challenging problem, due to uncertain hydrologic inputs and the need to adapt to changing environment and varying control objectives. In this work, we propose a real-time learning-based control strategy based on a hierarchical predictive control architecture. Two control loops are implemented: the inner loop is aimed to make the overall dynamics similar to an assigned linear model through data-driven control design, then the outer economic model-predictive controller compensates for model mismatches, enforces suitable constraints, and boosts the tracking performance. The effectiveness of the proposed approach is illustrated on an accurate simulator of the Hoa Binh reservoir in Vietnam. Results show that the proposed approach outperforms stochastic dynamic programming
A hierarchical mean field model of interacting spins
No full textWe consider a system of hierarchical interacting spins under dynamics of spin-flip type with a ferromagnetic mean field interaction, scaling with the hierarchical distance, coupled with a system of linearly interacting hierarchical diffusions of Ornstein-Uhlenbeck type. In particular, the diffusive variables enter in the spin-flip rates, effectively acting as dynamical magnetic fields. In absence of the diffusions, the spin-flip dynamics can be thought of as a modification of the Curie-Weiss model. We study the mean field and the two-level hierarchical model, in the latter case restricting to a subcritical regime, corresponding to high temperatures, obtaining macroscopic limits at different spatio-temporal scales and studying the phase transitions in the system. We also formulate a generalization of our results to the kth level hierarchical case, for any k finite, in the subcritical regime. We finally address the supercritical regime, in the zero-temperature limit, for the two-level hierarchical case, proceeding heuristically with the support of numerics. (C) 2021 Elsevier B.V. All rights reserved
A hierarchical mean field model of interacting spins
No full textWe consider a system of hierarchical interacting spins under dynamics of spin-flip type with a ferromagnetic mean field interaction, scaling with the hierarchical distance, coupled with a system of linearly interacting hierarchical diffusions of Ornstein–Uhlenbeck type. In particular, the diffusive variables enter in the spin-flip rates, effectively acting as dynamical magnetic fields. In absence of the diffusions, the spin-flip dynamics can be thought of as a modification of the Curie–Weiss model. We study the mean field and the two-level hierarchical model, in the latter case restricting to a subcritical regime, corresponding to high temperatures, obtaining macroscopic limits at different spatio-temporal scales and studying the phase transitions in the system. We also formulate a generalization of our results to the kth level hierarchical case, for any k finite, in the subcritical regime. We finally address the supercritical regime, in the zero-temperature limit, for the two-level hierarchical case, proceeding heuristically with the support of numerics
Oscillatory Behavior in a Model of Non-Markovian Mean Field Interacting Spins
No full textWe analyze a non-Markovian mean field interacting spin system, related to the Curie–Weiss model. We relax the Markovianity assumption by replacing the memoryless distribution of the waiting times of a classical spin-flip dynamics with a distribution with memory. The resulting stochastic evolution for a single particle is a spin-valued renewal process, an example of a two-state semi-Markov process. We associate to the individual dynamics an equivalent Markovian description, which is the subject of our analysis. We study a corresponding interacting particle system, where a mean field interaction-depending on the magnetization of the system-is introduced as a time scaling on the waiting times between two successive particle’s jumps. Via linearization arguments on the Fokker–Planck mean field limit equation, we give evidence of emerging periodic behavior. Specifically, numerical analysis on the discrete spectrum of the linearized operator, characterized by the zeros of an explicit holomorphic function, suggests the presence of a Hopf bifurcation for a critical value of the temperature. The presence of a Hopf bifurcation in the limit equation matches the emergence of a periodic behavior obtained by simulating the N-particle system
Data-driven design of explicit predictive controllers with structural priors
No full textIn this letter, we propose a data-driven approach to derive explicit predictive control laws. The key idea of the presented strategy is to exploit the prior knowledge that the optimal solution is a piece-wise affine controller. As the proposed method allows us to automatically retrieve also a model of the closed-loop system, we show that we can apply classical Lyapunov techniques to perform a prior stability check for safe controller deployment. The effectiveness of the proposed strategy is assessed on a benchmark simulation example, through which we also discuss the use of regularization and preprocessing techniques to handle the presence of noise.</p
Quasi-ordered P3HT nanopillar-nanocap structures with controlled size
No full textAbstract not availableA. Santos, P. Formentin, J. Pallarés, J. Ferré-Borrull, L.F. Marsa
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