1,725,081 research outputs found
Corrado Cagli e il suo magistero. Mezzo secolo di arte italiana dalla Scuola Romana all'astrattismo
No full textIn occasione del centenario della nascita di Corrado Cagli (1910-1976), nell’ottobre 2010, il Museo Civico d’Arte di Pordenone ha organizzato una grande mostra sull’artista, curata da Fabio Benzi, con il contributo tecnico di Francesco Leone e del direttore del Museo, Gilberto Ganzer.
Data la complessità dell’artista, si è messo a punto un progetto che rendesse omaggio alla sua grande versatilità intellettuale, che lo rese uno dei personaggi più straordinari e internazionali del Novecento italiano, capace di influenzare generazioni di artisti tra i maggiori del nostro Paese con la sua forza creativa e il suo magistero artistico.
L’enorme influenza artistica e culturale di Corrado Cagli si diffuse su una quantità di artisti e di movimenti, riconosciuta da tutti come determinante: dalla Scuola Romana a Corrente, dall’astrattismo del dopoguerra all’Informale.
Il catalogo della mostra è costituito da un’introduzione monografica su Cagli, di Fabio Benzi, in cui si ripercorre l’intero suo percorso artistico, e da una serie di sezioni nelle quali si mettono a fuoco i rapporti di influenza del Maestro sui suoi compagni di strada come sulle più giovani generazioni: Afro, Mirko, Dino, Capogrossi, Cavalli, Melli, Gentilini, Ziveri, Guttuso, Leoncillo, Fazzini, Purificato, Birolli, Tomea, Mafai, Franchina, Mannucci, Dova, Baj, Crippa, Tancredi, Scialoja, Pizzinato, Berti, Novelli e molti altri artisti dagli anni Trenta agli anni Sessanta. La vasta attività creativa di Cagli è presentata nella sua interezza, mettendola a confronto con quella dei suoi amici, illustrando così il ruolo di protagonista che rivestì in oltre mezzo secolo di dibattito artistico italiano e internazionale.
Il catalogo contiene anche saggi di E. Crispolti, A. Del Puppo, G. Ganzer, F. Leone, H. Romani. F. Benzi è autore, oltre che del saggio introduttivo (pp. 13-51), di Cagli e il gruppo della Scuola Romana (pp. 199-204), Cagli e la Scuola Romana tra Tonalismo, espressionismo e neo-barocco (p.214-223)
Modelling the COVID-19 Pandemic: Epidemiological, Epistemological, and Ethical Challenges
No full textIf we were seeking consolation for the huge difficulties that have plagued us since the COVID-19 pandemic broke out, we might draw some comfort from the breadth and depth of the discussions that it has given rise to, for all that these have often led to the expression and propagation of misleading views. The present number of Argumenta opens with a Special Issue that intends to take stock of the tenor and quality of these discussions, bringing to light the awareness that we have been acquiring over the last few months about our overall cognitive situation.
The Special Issue, edited by Margherita Benzi, Raffaella Campaner and Francesco Barone-Adesi, is entitled Modelling the COVID-19 Pandemic: Epidemiological, Epistemological, and Ethical Challenges, and draws attention to the intricacy of formulating models that take into account the many factors at work in a pandemic. The result is an up-to-date discussion of these aspects that, by focusing on epistemological and epidemiological views, seek to identify what epistemic virtues should guide the choice of models for explanatory and predictive purposes
Per una più moderna cultura giuridica (3). Intervista di Angelo Costanzo a Margherita Benzi
No full textFormazione giurifica, logica, teoria dell'argomentazion
Performance and stability of direct methods for computing generalized inverses of the graph Laplacian. ETNA - Electronic Transactions on Numerical Analysis
Get PDFWe consider the computation of generalized inverses of the graph Laplacian for both undirected and directed graphs, with a focus on the group inverse and the closely related absorption inverse. These generalized inverses encode valuable information about the underlying graph as well as the regular Markov process generated by the graph Laplacian. In [Benzi et al., Linear Algebra Appl., 574 (2019), pp. 123–152], both direct and iterative numerical methods have been developed for the efficient computation of the absorption inverse and related quantities. In this work, we present two direct algorithms for the computation of the group inverse and the absorption inverse. The first is based on the Gauss-Jordan elimination and the reduced row echelon form of the Laplacian matrix and the second on the bottleneck matrix, the inverse of a submatrix of the Laplacian matrix. These algorithms can be faster than the direct algorithms proposed in [Benzi et al., Linear Algebra Appl., 574 (2019), pp. 123–152]
Statistical properties of low-frequency variability in the Northern Hemisphere
No full textWe discuss some statistical properties of the observed tropospheric circulation in Northern Hemisphere mid-latitudes. The data used consist of the twice-daily 500 mb height NMC analyses for the period 1966–77. Our analysis is performed in the context of the quasi-unidimensional theory. Estimates of the probability distribution of wave amplitude in the low-frequency range (10–40 days) seem to reveal a bimodal character, while similar estimates for the zonal wind fail to show stable multiple peaks in the occupation frequency, although the process involved seems to be more complex than Gaussian. Possible dynamical interpretations of such statistical properties are discussed in the light of other properties resulting from different types of analysis. The emerging physical picture reveals an intermittent process, operating on planetary scales through a predominantly baroclinic conversion, in agreement with the theoretical considerations of Benzi et al
Ranking hubs and authorities using matrix functions
No full textThe notions of subgraph centrality and communicability, based on the exponential of the adjacency matrix of the underlying graph, have been effectively used in the analysis of undirected networks. In this paper we propose an extension of these measures to directed networks, and we apply them to the problem of ranking hubs and authorities. The extension is achieved by bipartization, i.e., the directed network is mapped onto a bipartite undirected network with twice as many nodes in order to obtain a network with a symmetric adjacency matrix. We explicitly determine the exponential of this adjacency matrix in terms of the adjacency matrix of the original, directed network, and we give an interpretation of centrality and communicability in this new context, leading to a technique for ranking hubs and authorities. The matrix exponential method for computing hubs and authorities is compared to the well known HITS algorithm, both on small artificial examples and on more realistic real-world networks. A few other ranking algorithms are also discussed and compared with our technique. The use of Gaussian quadrature rules for calculating hub and authority scores is discussed
Localization in matrix computations: Theory and applications
No full textMany important problems in mathematics and physics lead to (nonsparse) functions, vectors, or matrices in which the fraction of nonnegligible entries is vanishingly small compared the total number of entries as the size of the system tends to infinity. In other words, the nonnegligible entries tend to be localized, or concentrated, around a small region within the computational domain, with rapid decay away from this region (uniformly as the system size grows). When present, localization opens up the possibility of developing fast approximation algorithms, the complexity of which scales linearly in the size of the problem.While localization already plays an important role in various areas of quantum physics and chemistry, it has received until recently relatively little attention by researchers in numerical linear algebra. In this chapter we survey localization phenomena arising in various fields, and we provide unified theoretical explanations for such phenomena using general results on the decay behavior of matrix functions. We also discuss computational implications for a range of applications
A Relaxed Dimensional Factorization preconditioner for the incompressible Navier–Stokes equations
Get PDFIn this paper we introduce a Relaxed Dimensional Factorization (RDF) preconditioner for saddle point problems. Properties of the preconditioned matrix are analyzed and compared with those of the closely related Dimensional Splitting (DS) preconditioner recently introduced by Benzi and Guo [7]. Numerical results for a variety of finite element discretizations of both steady and unsteady incompressible flow problems indicate very good behavior of the RDF preconditioner with respect to both mesh size and viscosity. © 2011 Elsevier Inc
Tuning of Heterocyclic Ring in <i>Para</i>-Benzi Heterosapphyrins
No full textThree examples of moderately aromatic p-benzi
dithiasapphyrin and p-benzi tellurathiasapphyrins
have been synthesized by condensing p-benzithiophene
diol with 16-thia/telluratripyrrane under acid-catalyzed reaction
conditions. The X-ray structural analysis showed that the thiophene
ring in p-benzi dithiasapphyrin was inverted, whereas
the tellurophene ring in p-benzi tellurathiasapphyrins
was normal conformation with respect to the macrocyclic core. However,
NMR studies revealed that the thiophene ring in protonated p-benzi dithiasapphyrin flips to normal, whereas the tellurophene
ring in p-benzi tellurathiasapphyrins flips to inverted
orientation
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