328,935 research outputs found
Dalle Accademie agrarie all'Università. L'istituzionalizzazione dell'economia politica a Macerata e nelle Marche
No full textLa ricerca contenuta in questo volume - composto da una Introduzione di Bini e da 11 saggi di autori vari - mira a ricostruire i modi e i canali attraverso i quali gli studi di agronomia e di economia effettuati in varie istituzioni della regione Marche hanno fornito un non trascurabile contributo al processo di modernizzazione economica, politica e civile del territorio marchgiano durante tutto l'Ottocento, e soprattutto nel periodo post-unitario
Reply to Claus Riedl's Letter to the Editor re: Antonella Giannantoni, Vittorio Bini, Roger Dmochowski, et al. Contemporary Management of the Painful Bladder: A Systematic Review
No full textReply to Claus Riedl's Letter to the Editor re: Antonella Giannantoni, Vittorio Bini, Roger Dmochowski, et al. Contemporary Management of the Painful Bladder: A Systematic Review
Improved cyclic reduction for solving queueing problems
No full textThe cyclic reduction technique (Buzbee et al., 1970), rephrased in functional form (Bini and Meini, 1996), provides a numerically stable, quadratically convergent method for solving the matrix equation X = Sigma(i=0)(+infinity) X(i)A(i), where the A(i)'s are nonnegative k x k matrices such that Sigma(i=0)(+infinity) A(i) is column stochastic. In this paper we propose a further improvement of the above method, based on a point-wise evaluation/interpolation at a suitable set of Fourier points, of the functional relations defining each step of cyclic reduction (Bini and Meini, 1996). This new technique allows us to devise an algorithm based on FFT having a lower computational cost and a higher numerical stability. Numerical results and comparisons are provided
Human-Environment Relationship and Landscape Evolution since Etruscan Times: Case Studies from Apuo-Versilia Plain and Pisa Urban Area (NW Italy)
No full textDuring the last millennia human and natural processes in the Mediterranean Basin have become strongly intertwined, modifying the Earth’s surface in many different ways (Butzer, 2008; Zanchetta et al., 2013). Evident traces of this joint human-nature activity can be detected in coastal areas and alluvial plains, where an enduring synergic relationship commonly occurs between landscape, ancient cultures and society evolution (Butzer, 2008).
A holistic geoarchaeological approach helps understand the history of these areas encompassing both natural and human-induced changes. In this regards interesting cases are the Apuo-Versilia plain and the Pisa urban area.
For instance the Apuo-Versilia plain experienced a discontinuous progradation of the coastline between Etruscan times and the Middle Ages. A change in the progradation rate was documented after Modern Age and was related to an increase in flood frequencies due to the overlap of climate events and human impact (Bini et al. 2013).
Whereas, Pisa is a multilayered city located nowadays on a 4 m-high mound composed of anthropogenic, made-ground deposits dated from the Roman period onwards (Bini et al., 2015). These deposits, totally due to human activities, overlie alluvial, man-modified sediments recording intense human frequentation in a context of a natural environment developed since the early Etruscan age. Changes in Pisa topography through time, quantified using stratigraphic data and the Digital Elevation Model for five historical periods, indicate that the maximum increase in volume and thickness of anthropogenic deposits occurs during the Etruscan-Roman transition, which potentially corresponds to the local onset of the Anthropocene. Integration of DEM analysis with high-resolution stratigraphy allows to reconstruct the spatio-temporal distribution patterns of human frequentation and urban ground growth.
The comparison of these two sectors, therefore, indicates interesting relation between human activity and change in the landscape
A computational framework for two-dimensional random walks with restarts
No full textThe treatment of two-dimensional random walks in the quarter plane leads to Markov processes which involve semi-infinite matrices having Toeplitz or block Toeplitz structure plus a low-rank correction. We propose an extension of the framework introduced in [D. A. Bini, S. Massei, and B. Meini, Math. Comp., 87 (2018), pp. 2811-2830] which allows us to deal with more general situations such as processes involving restart events. This is motivated by the need for modeling processes that can incur in unexpected failures like computer system reboots. We present a theoretical analysis of an enriched Banach algebra that, combined with appropriate algorithms, enables the numerical treatment of these problems. The results are applied to the solution of bidimensional quasi-birth-death processes with infinitely many phases which model random walks in the quarter plane, relying on the matrix analytic approach. The reliability of our approach is confirmed by extensive numerical experimentation on several case studies
Dalle Accademie Agrarie all’Università. L’istituzionalizzazione dell’economia politica a Macerata e nelle Marche.
No full textQuesto libro contiene i risultati di varie ricerche effettuate originariamente nel corso degli anni Novanta da alcuni studiosi legati all’Università di Macerata, coordinati da Piero Bini. Tali ricerche dimostrano che l’economia politica ha fornito un non trascurabile contributo al processo di modernizzazione economica, politica e civile del territorio marchigiano durante tutto l’Ottocento, ma soprattutto nel periodo post-unitario. Un momento in un certo senso emblematico di questo processo è da ravvisarsi nell’istituzione, nel 1861, della cattedra di economia politica presso l’Università di Macerata
Geografia e ecologia politica: teorie, pratiche, discorsi
No full textLa storia dell'ecologia politica si intreccia profondamente da un lato con la geografia umana, dall'altro con la militanza ecologista e con la demistificazione dei discorsi dei poteri politici ed economici sull'ambiente. L'ecologia politica è piuttosto recente tra gli autori italiani, ma affonda le sue radici nel magistero di Lucio Gambi e della svolta della geografia umana italiana dagli anni Settanta in poi a favore dell'impegno della disciplina nella trasformazione della società circa i suoi impatti sul territorio
Politiques sanitaires et ségrégation urbaine dans les villes africaines: de la peur de l'épidémie à l'épidémie de la peur
No full textVodun Sakpata et épidémie de variole dans la littérature orale sacrée du golfe du Benin, M. KAKPO - Politiques sanitaires et ségrégation urbaine dans les villes africaines: de la peur de l’épidémie à l’épidémie de la peur, V. BINI - Le “mal invisible”: sida et littérature africaine francophone, J. MICONI - L’épidémie de vert dans On a giflé la montagne! de Yamba Élie Ouédraogo, F. PARABOSCHI - De la Terre à la Lune et retour. La mise en abyme des épidémies historiques dans ...Et l’homme triompha! de Makouta-Mboukou, S. RIVA - “Était-ce bien ça, l’Amérique?” L’été de l’île de Grâce entre le mythe et l’histoire, M. MODENESI - La variole ou l’inéluctable déshumanisation dans Les Tortues de Loys Masson, V. MOOTOSAMY - Épidémies dans les vocabulaires francophones. Une exploration “transversale” de la BDLP, C. BRANCAGLION - Études linguistiques, dir. C. BRANCAGLION - Francophonie européenne, dir. G.L. DI BERNARDINI - Francophonie du Maghreb, dir. D. MAURI - Francophonie de l’Afrique subsaharienne, dir. Liana NISSIM et M. B. COLLINI - Francophonie du Québec et du Canada, dir. A. FERRARO - Francophonie des Caraïbes, dir. M. MODENESI - OEuvres générales et autres francophonies, dir. S. RIVA
Solving secular and polynomial equations: A multiprecision algorithm
No full textWe present an algorithm for the solution of polynomial equations and secular equations of the form for , which provides guaranteed approximation of the roots with any desired number of digits. It
relies on the combination of two different strategies for dealing with the precision of the floating point computation: the strategy used in the package MPSolve of D.~Bini and G.~Fiorentino [Numer.~Algo.~23, 2000] and the strategy used in the package Eigensolve of S.~Fortune [J. Symb. Comput.~33, 2002]. The algorithm is based on the Ehrlich-Aberth (EA) iteration, and on several results introduced in the paper. In particular, we extend the concept and the properties of root-neighborhoods from polynomials to secular functions, provide perturbation results of the roots, obtain an effective stop condition for the EA iteration and guaranteed a posteriori error ounds. We provide an implementation, released in the package MPSolve 3.0, based on the GMP library. From the many numerical experiments it turns out that our code is generally much faster than MPSolve 2.0 and of the package Eigensolve. For certain polynomials, like the Mandelbrot or the partition polynomials the acceleration is dramatic. The algorithm exploits the parallel architecture of the computing platform
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