1,721,114 research outputs found
Leveraging, Capture and Resistance: Local Adaptation of the Discourse on European Cohesion Policies in Italian Regions
Full text linkCohesion policy accounts for more than one third of the budget of the European Union, but research mostly focuses on economic aspects. In this paper we tackle the discursive dimension of cohesion policy, and in particular, we address the debate on newspapers at national and regional level. As regions can be deemed as the product of struggle over meaning, and as discourses are able to mould and change reality and how we perceive it, we explore the topics used by media when dealing with Cohesion Policy, and in particular we address to what extent national and regional debate differ, also considering regions that differ according to the effectiveness of funds’ management. We performed a topic model on newspapers articles, and we also collected economic data through Eurispes. Our findings point at three processes, which we called leverage, capture, and resistance, which define the local (regional) adaptation of national discourses on cohesion policy. These processes reflect entrenched power relations and depend on the specific context of programming periods, on contingent events, and on structural factors pertaining to regions’ history of economic and social development
High order pressure-based semi-implicit IMEX schemes for the 3D Navier-Stokes equations at all Mach numbers
No full textThis article aims at developing a high order pressure-based solver for the solution of the 3D compressible Navier-Stokes system at all Mach numbers. We propose a cell-centered discretization of the governing equations that splits the fluxes into a fast and a slow scale part, that are treated implicitly and explicitly, respectively. A novel semi-implicit discretization is proposed for the kinetic energy as well as the enthalpy fluxes in the energy equation, hence avoiding any need of iterative solvers. The implicit discretization yields an elliptic equation on the pressure that can be solved for both ideal gas and general equation of state (EOS). A nested Newton method is used to solve the mildly nonlinear system for the pressure in case of nonlinear EOS. High order in time is granted by implicit-explicit (IMEX) time stepping, whereas a novel CWENO technique efficiently implemented in a dimension-by-dimension manner is developed for achieving high order in space for the discretization of explicit convective and viscous fluxes. A quadrature-free finite volume solver is then derived for the high order approximation of numerical fluxes. Central schemes with no dissipation of suitable order of accuracy are finally employed for the numerical approximation of the implicit terms. Consequently, the CFL-type stability condition on the maximum admissible time step is based only on the fluid velocity and not on the sound speed, so that the novel schemes work uniformly for all Mach numbers. Convergence and robustness of the proposed method are assessed through a wide set of benchmark problems involving low and high Mach number regimes, as well as inviscid and viscous flows
Time relaxed Monte Carlo methods for the Boltzmann equation
No full textA new family of Monte Carlo schemes is introduced for the numerical solution of the Boltzmann equation of rarefied gas dynamics. The schemes are inspired by the Wild sum expansion of the solution of the Boltzmann equation for Maxwellian molecules and consist of a novel time discretization of the equation. In particular, high order terms in the expansion are replaced by the equilibrium Maxwellian distribution. The two main features of the schemes are high order accuracy in time and asymptotic preservation. The first property allows to recover accurate solutions with time steps larger than those required by direct simulation Monte Carlo (DSMC), while the latter guarantees that for the vanishing Knudsen number, the numerical solution relaxes to the local Maxwellian. Conservation of mass, momentum, and energy are preserved by the scheme. Numerical results on several space homogeneous problems show the improvement of the new schemes over standard DSMC. Applications to a one-dimensional shock wave problem are also presented
La selezione degli inediti di narrativa nel campo editoriale contemporaneo
No full textIn questo articolo mostreremo in che modo viene effettuata la selezione di opere di autori inediti nel campo editoriale italiano contemporaneo. L'analisi si inserisce in una più ampia ricerca, il cui obiettivo è studiare il settore della produzione editoriale di narrativa italiana e, in particolare, il processo di ammissione alla produzione di autori esordienti: quel processo che ha inizio con un aspirante autore, con un dattiloscritto, e termina con una casa editrice che accetta l’inedito per la pubblicazione. La ricerca è stata condotta in due fasi, con tecniche qualitative, attraverso interviste semi-strutturate. Nella prime sono stati intervistati editori,
direttori editoriali ed editor di 13 case editrici diverse per dimensione, localizzazione e orientamento verso gli esordienti. Nella seconda si è risaliti lungo i canali di approvvigionamento dei manoscritti: qui sono stati intervistati agenti che costituiscono il campo editoriale, indicati come importanti per la ricerca e selezione degli inediti. Sono state realizzate in tutto 57 interviste, fra il 2010 e la prima metà del 2011. Ognuna è stata trascritta fedelmente e codificata per l’analisi con l’aiuto del software Nvivo. Coerentemente con la letteratura sulla ricerca qualitativa, le interviste sono considerate sia come accesso ad una realtà esterna, che come narrazione: sono quindi analizzate sia per descrivere le caratteristiche oggettive del lavoro degli agenti del campo editoriale, che il senso soggettivo che ognuno ha del proprio ruolo. L’articolo è così strutturato: in primo luogo presentiamo le risposte degli editor circa le caratteristiche ricercate nei manoscritti; analizzeremo poi il rapporto fra ricerca di qualità o di libri che possano avere successo di vendita. Il terzo paragrafo è dedicato alla ricerca di esordienti: come e perché viene effettuata. Seguono le versioni degli agenti letterari e degli altri attori che, dalle loro posizioni nel campo editoriale, contribuiscono alla produzione materiale e simbolica dei libri
How I Met My Publisher: Casual and Serial Intermediaries in First-Time Authors’ Publication in the Italian Literary Field
No full textWhich cultural intermediaries are involved in the search for, and selection of, aspiring authors in the Italian book publishing industry? What do they do and why? I provide an in-depth description of cultural intermediaries involved in book production, based on a study of the Italian literary field, which has been characterised in recent years by an intense search for successful books by first-time authors. I find that two types of intermediaries are involved in the book pre-selection process: casual intermediaries who occasionally build on their position within the field to broker manuscripts between aspiring authors and publishers, and serial intermediaries who choose repeatedly to act as gatekeepers. Both types of intermediaries are rewarded with social capital, whereas serial intermediaries earn symbolic capital as well. Publishers rely on the same intermediaries for the selection of both literary and popular fiction. Cooperation among agents in the field is more common than expected
What editors talk about when they talk about editors? A public discourse analysis of market and aesthetic logics
No full textIn this paper, we address the topic of the changing relationships between market and aesthetic logics in fields of cultural production with a focus on public discourse. We explore the contemporary Italian literary field and examine editors’ public discursive reconstructions of their work related to the media to understand the particular shape of market and aesthetic logics in their public discourse and explain the influencing factors. Using a text analysis of 87 media interviews combining topic modeling and multiple correspondence analysis, we inductively explore how editors narrate their work. Far from incorporating a market discourse, editors mostly maintain an idiosyncratic discourse focusing on aesthetic values, experience with books and publishers, intellectual status and skills. Surprisingly, publishers’ sizes and geographical locations, but not the industry structure or professional role within the field, are organizational factors that account for the balance between market and aesthetic discourses as editors working for medium-sized publishers are more prone to address aesthetic issues, while editors working for large publishers are more prone to refer to personal experience, and only editors working for small publishers explicitly refer to the market logic
Dinamiche sociali ed equazioni alle derivate parziali in ambito epidemiologico
No full textIn questo breve sunto divulgativo discuteremo l’importanza delle dinamiche sociali in ambito epidemico e la loro modellizzazione matematica tramite equazioni alle derivate parziali. Presenteremo inizialmente modelli di interazione tra individui in cui le caratteristiche sociali, come l’età degli individui, il numero di contatti sociali e la loro ricchezza economica, giocano un ruolo chiave nella diffusione di un’epidemia. Successivamente, accenneremo a modelli che tengono conto anche di caratteristiche aggiuntive quali la carica virale e le difese immunitarie dell’individuo. Infine, analizzeremo alcuni modelli alle derivate parziali per la descrizione degli spostamenti degli individui, sia su scala urbana che extra urbana, ed evidenzieremo come le dinamiche di movimento giochino un ruolo chiave sull’avanzamento dell’epidemia
From agent-based models to the macroscopic description of fake-news spread: the role of competence in data-driven applications
Full text linkFake news spreading, with the aim of manipulating individuals' perceptions of
facts, is now recognized as a major problem in many democratic societies. Yet,
to date, little has been understood about how fake news spreads on social
networks, what the influence of the education level of individuals is, when
fake news is effective in influencing public opinion, and what interventions
might be successful in mitigating their effect. In this paper, starting from
the recently introduced kinetic multi-agent model with competence by the first
two authors, we propose to derive reduced-order models through the notion of
social closure in the mean-field approximation that has its roots in the
classical hydrodynamic closure of kinetic theory. This approach allows to
obtain simplified models in which the competence and learning of the agents
maintain their role in the dynamics and, at the same time, the structure of
such models is more suitable to be interfaced with data-driven applications.
Examples of different Twitter-based test cases are described and discussed.Comment: Minor changes to align the manuscript to its published versio
An implicit Monte arlo method for rarefied gas dynamics - 1. The space homogeneous case
No full textFor the space homogeneous Boltzmann equation, we formulate a hybrid Monte Carlo method that is robust in the fluid dynamic limit. This method is based on an analytic representation of the solution over a single time step and involves implicit time differencing derived from a suitable power series expansion of the solution (a generalized Wild expansion). A class of implicit, yet explicitly implementable, numerical schemes is obtained by substituting a Maxwellian distribution in place of the high order terms in the expansion. The numerical solution is represented as a convex combination of a non-equilibrium particle distribution and a Maxwellian. The hybrid distribution is then evolved by Monte Carlo using the implicit formulation for the time evolution. Computational simulations of spatially homogeneous problems by our method are presented here for the Kac model and for the variable hard sphere model (including Maxwell molecules). Comparison to exact solutions and to direct simulation Monte Carlo (DSMC) computations shows the robustness and the efficiency of the new method
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