1,989 research outputs found
Out-of-equilibrium dynamics of repulsive Fermi gases in quasi-periodic potentials: a Density Functional Theory study
The dynamics of a one-dimensional two-component Fermi gas in the presence of
a quasi-periodic optical lattice (OL) is investigated by means of a Density
Functional Theory approach. Inspired by the protocol implemented in recent
cold-atom experiments, designed to identify the many-body localization
transition, we analyze the relaxation of an initially prepared imbalance
between the occupation number of odd and of even sites. For quasi-disorder
strength beyond the Anderson localization transition, the imbalance survives
for long times, indicating the inability of the system to reach local
equilibrium. The late time value diminishes for increasing interaction
strength. Close to the critical quasi-disorder strength corresponding to the
noninteracting (Anderson) transition, the interacting system displays an
extremely slow relaxation dynamics, consistent with sub-diffusive behavior. The
amplitude of the imbalance fluctuations around its running average is found to
decrease with time, and such damping is more effective with increasing
interaction strengths. While our study addresses the setup with two equally
intense OLs, very similar effects due to interactions have been observed also
in recent cold-atom experiments performed in the tight-binding regime, i.e.
where one of the two OLs is very deep and the other is much weaker.Comment: Published version, 8 pages, 5 figure
City Branding and Public Space: An empirical analysis of Dolce & Gabbana's Alta Moda event in Naples
This article focuses on the celebration of the thirtieth anniversary of D&G held in Naples in June 2016. For this event iconic places of the city were used as the backdrop of the Alta Moda Fall/Winter 2016 collection. For a few days, access to different areas of 'Centro Storico' (the Neapolitan's downtown) were closed to the general public generating controversial opinions on the phenomenon of privatization of the public space. The study presents an empirical analysis of the video produced for the event and it focuses on the elements that characterize Naples as a cultural artifact capturing the authenticity of Southern Italy and simultaneously meeting the brand values of D&G. The findings revealed how the urban space becomes a tool to emphasize the core values of the fashion brand and how this process enhances the image of the city as a historical and cultural center, essence of Mediterranean and Italian culture
Construction Productivity Graph. A Structured Framework to Enhance Productivity and Safety on Construction Sites
The construction industry is characterised by the constant production of unique products in dynamic contexts where, moreover, the workplace coincides with the product itself. This limits the adoption of standardization and process automation methodologies. Furthermore, the average size of professional firms and companies often does not allow for investments in process innovation or skills development. Then, we need to consider that construction is a highly risky activity, also to the lack of standardization as aforementioned. The paper aims to present the framework of a methodology based on linking the information managed by a BIM model with Agent-based simulation techniques - ABS. The scope is to simulate the duration of the work under efficient conditions, understood as the best occupation of the available areas by a suitable number of workers. The result is the Construction Productivity Graph - CPG, a graph that indicates the optimization level of the construction process
Are low frequency macroeconomic variables important for high frequency electricity prices?
We analyse the importance of low frequency hard and soft macroeconomic
information, respectively the industrial production index and the manufacturing
Purchasing Managers' Index surveys, for forecasting high-frequency daily
electricity prices in two of the main European markets, Germany and Italy. We
do that by means of mixed-frequency models, introducing a Bayesian approach to
reverse unrestricted MIDAS models (RU-MIDAS). Despite the general parsimonious
structure of standard MIDAS models, the RU-MIDAS has a large set of parameters
when several predictors are considered simultaneously and Bayesian inference is
useful for imposing parameter restrictions. We study the forecasting accuracy
for different horizons (from day ahead to days ahead) and by
considering different specifications of the models. Results indicate that the
macroeconomic low frequency variables are more important for short horizons
than for longer horizons. Moreover, accuracy increases by combining hard and
soft information, and using only surveys gives less accurate forecasts than
using only industrial production data.Comment: This paper has previously circulated with the title: "Forecasting
daily electricity prices with monthly macroeconomic variables" (ECB Working
paper Series No. 2250
"IO PER ME SONO UN'OMBRA". GIOVAN BATTISTA STROZZI IL GIOVANE (1551 - 1634) FRA POESIA E RIFLESSIONE LETTERARIA
La tesi propone uno studio monografico sul fiorentino Giovan Battista Strozzi il Giovane detto il Cieco (1551-1634), letterato e animatore di circoli culturali dalla Firenze medicea alla Roma barberiniana, attraverso la Milano borromaica e i cenacoli capitolini degli Aldobrandini e degli Umoristi. Nel primo dei tre capitoli che scandiscono la ricerca si è appuntata l’attenzione sulla partecipazione del Giovane alle attività di due vivaci consessi della sua città natale: l’Accademia Fiorentina e l’Accademia degli Alterati. Nel secondo è stata condotta una disamina dell’opera in versi – per la maggior parte ancora inedita – che comprende decine di epistole metriche in endecasillabi sciolti, un incompiuto poema in onore di Amerigo Vespucci, nonché un ricco corpus di madrigali, la cui stesura, nell’esperienza del Cieco, procedette di conserva con la speculazione teorica intorno alla nuova fisionomia cinquecentesca di questo antico genere lirico. La terza sezione si concentra invece sul contributo dello Strozzi alle discussioni di poetica (la ‘Commedia’ dantesca, il poema eroico, le unità aristoteliche) che accesero gli ambienti letterari italiani nella seconda metà del secolo XVI. Affiancando l’esegesi dei testi alla ricostruzione biografica – condotta su un ampio numero di documenti epistolari editi e inediti –, si è cercato di restituire il giusto spessore storico a ciascuno degli scritti presi in esame, ricostruendo i differenti contesti culturali in cui furono composti e scandagliando la fitta trama di relazioni – umane e letterarie – che si profila sullo sfondo di essi. Completano il lavoro una bibliografia delle opere antiche e moderne, un indice dei manoscritti e un indice dei nomi di persona.The thesis proposes a monographic study on the Florentine Giovan Battista Strozzi the Younger also known as the Blind (1551-1634). He was a writer with connections in cultural circles across Renaissance Italy, including Medici’s Florence, Barberini’s Rome, Borromean Milan and the Roman cenacles of the Aldobrandini and the Humorists. The thesis consists of three chapters. The first chapter focuses on the participation of Strozzi the Younger in the activities of two lively groups in his hometown: the Florentine Academy and the Alterati Academy. The second chapter discusses his poetical works – for the most part still unpublished –, including dozens of versified epistles in loose hendecasyllables, an unfinished poem in honor of Amerigo Vespucci, as well as a rich corpus of madrigals. The drafting of this last corpus proceeded together with Strozzi the Younger’s theoretical speculation around the new sixteenth-century appearance of this ancient lyrical genre. The third section considers the contribution of Strozzi the Younger to the discussions on poetics (Dante’s ‘Comedy’, the heroic poem, the Aristotelian units) that went on in Italian literary circles in the second half of the sixteenth century. In this work, we aimed to restore the appropriate historical depth to each of the writings examined, through the exegesis of texts combined with the biographical reconstruction conducted on a large number of published and unpublished epistolary documents. We also tried to reconstruct the different cultural contexts in which these writings were composed and attempted to analyze the dense network of relationships, both human and literary, that loomed in the background. The thesis is completed by a bibliography of ancient and modern works, an index of manuscripts and an index of names
Metodologie progettuali digitali per l’ottimizzazione, il controllo e la gestione dei processi di realizzazione dell’architettura
La tesi si propone di analizzare le attuali metodologie per la gestione del processo edilizio e le prospettive che queste possono avere, in parallelo allo sviluppo delle possibilità e competenze informatiche raggiunte dal settore della progettazione e costruzione dell'architettura. Tali metodologie vengono introdotte e analizzate mediante un esteso approfondimento storico e dello stato dell'arte, al fine di meglio definire il quadro di riferimento e gli indirizzi delle linee di ricerca del settore. Nella parte sperimentale, si riportano i risultati ottenuti dall'impiego del prototipo informatico sviluppato. Questo applicativo combina le potenzialità della modellazione informativa dell'edificio (BIM) con tecniche di Intelligenza Artificiale, in tre casi studio. I risultati dimostrano chiaramente i vantaggi, in termini economici e di durata del cantiere, e aprono la strada ad ulteriori sviluppi delle sinergie tra informatica e ingegneria per l'architettura
Educare a convivere. Una ricerca empirica nella scuola secondaria di primo grado
In order to know the relational dynamics underlying school coexistence, a descriptive study of correlation was carried out through the administration of a questionnaire to a sample of 2080 students and 119 teachers from nine Apulian secondary schools. The main objective of the research was to identify the types of disturbing behaviors, with particular attention to the indiscipline. The first results highlight the need of a pedagogical intervention focused on the adolescent disaffection and on the promotion of a “positive discipline”.Al fine di conoscere le dinamiche relazionali alla base della convivenza scolastica, è stato svolto uno studio descrittivo di correlazione attraverso la somministrazione di un questionario a un campione di 2080 studenti e 119 docenti di nove scuole secondarie di primo grado pugliesi. Obiettivo principale della ricerca è stato identificare le tipologie di comportamenti di disturbo, con particolare attenzione all’indisciplina. I primi risultati sottolineano l’esigenza di un intervento pedagogico incentrato sulla presa in carico del disagio scolastico e sulla promozione di una “positive discipline”
Coherent excitation transport through ring-shaped networks
The coherent quantum transport of matter wave through a ring-shaped circuit
attached to leads defines an iconic system in mesoscopic physics that has
allowed both to explore fundamental questions in quantum science and to draw
important avenues for conceiving devices of practical use.
Here we study the source-to-drain transport of excitations going through a
ring-network, without propagation of matter waves. We model the circuit in
terms of a spin system with specific long-range interactions that are relevant
for quantum technology, such as Rydberg atoms trapped in optical tweezers or
ion traps. Inspired by the logic of rf- and dc-SQUIDs, we consider rings with
one and two local energy offsets, or detunings. As a combination of specific
phase shifts in going though the localized detunings and as a result of
coherent tunneling, we demonstrate how the transport of excitations can be
controlled, with a distinctive dependence on the range of interactions.Comment: Main text: 9 pages, 4 figures. Appendix: 16 pages, 10 figure
Fuzzy Logic Method for the Speed Estimation in All-Wheel Drive Electric Racing Vehicles
This paper presents a method for the vehicle speed estimation with a Fuzzy Logic based algorithm. The algorithm acquires the measurements of the yaw rate, steering angle, wheel velocities and exploits a set of five Fuzzy Logics dedicated to different driving conditions. The technique estimates the speed exploiting a weighted average of the contributions provided by the longitudinal acceleration and the credibility assigned by the Fuzzy Logics to the measurements of the wheels' speed. The method is experimentally evaluated on an all-wheel drive electric racing vehicle and is valid for the front and rear wheel drive configurations. The experimental validation is performed by comparing the obtained estimation with the result of computing the speed as the average of the linear velocity of the four wheels. A comparison to the integral of the vehicle acceleration over time is reported
Controlled flow of excitations in a ring-shaped network of Rydberg atoms
Highly excited Rydberg atoms are a powerful platform for quantum simulation
and information processing. Here, we propose atomic ring networks to study
chiral currents of Rydberg excitations. The currents are controlled by a phase
pattern imprinted via a Raman scheme and can persist even in the presence of
dephasing. Depending on the interplay between the Rabi coupling of Rydberg
states and the dipole-dipole atom interaction, the current shows markedly
different features. The excitations propagate with a velocity displaying a
characteristic peak in time, reflecting the chiral nature of the current. We
find that the time-averaged current in a quench behaves similarly to the
ground-state current. This analysis paves the way for the development of new
methods to transport information in atomic networks.Comment: 6 pages main, 6 figures + appendice
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