170,293 research outputs found
Planol de la carretera de Madrid a França per la Jonquera : travessia d'El Masnou / Aureli Farguer (?). El Masnou, agost del 1936
No full text1 Mapa. - Obra atribuïda Aureli Farguer.1:50033 x 449 c
Planol de la carretera de Madrid a França per la Jonquera : travessia d'El Masnou / Aureli Farguer (?). El Masnou, agost del 1936
No full text1 Mapa. - Obra atribuïda Aureli Farguer.1:50033 x 449 c
Nuovi approfondimenti di studio nell’ambito del comparto delle piccole imprese: le ethnic and minority businesses
No full textTra i vari ambiti di specializzazione dell’Economia Aziendale, un campo di indagine particolarmente importante è rappresentato dal comparto delle piccole imprese, le cui peculiarità hanno fatto emergere, fin dai primi anni ’80, la necessità di individuare modelli interpretativi diversi da quelli sviluppati in letteratura con riferimento alle grandi imprese (Atti del Convegno AIDEA, 1986). In effetti, la dimensione limitata e la centralità dei fattori soggettivi legati della figura dell’imprenditore proprietario non sempre rendevano applicabili le teorie generali di governo aziendale (Marchini, 1995), ma indicavano addirittura l’esistenza di diverse tipologie di piccole imprese, aventi specifici problemi di governo e difficilmente riconducibili ad un modello unitario (Marchini, 2002).
Negli ultimi anni, a seguito dell’incremento dei flussi migratori verso i Paesi più industrializzati, è apparsa, all’interno di questo eterogeneo comparto, una nuova classe di imprese (c.d. ethnic and minority businesses) distinguibili in virtù della nazionalità o dell’etnia di appartenenza dell’imprenditore. Il fenomeno -indicato in Italia con il termine di imprenditorialità straniera o immigrata- ha assunto una dimensione rilevante (Caritas, 2007), apportando benefici sia economici che sociali. Tuttavia, poche e molto frammentate sono le ricerche sul tema (Aureli, 2005).
Spinti dalla necessità di superare l’attuale stato delle ricerche italiane, peraltro non sempre condotte con rigore scientifico, ed integrare nella nostra dottrina lo studio di questa nuova realtà economica, ci proponiamo, innanzitutto, di analizzare le teorie interpretative sviluppate a livello internazionale nell’ambito di studi specialistici, appartenenti anche a discipline diverse, per poi verificare se la creazione ed i comportamenti di queste imprese possono essere efficacemente spiegati anche attraverso teorie aziendali generali già note, sì da riflettere sulla validità dei principi teorici costruiti nel tempo dagli studiosi di Economia Aziendale e sui potenziali benefici derivanti dall’applicazione di concetti derivanti da discipline diverse
Analisi informativa: un approccio orientato alla pragmatica
No full text2005 Crocco C., Aureli M., “Analisi informativa: un approccio orientato alla pragmatica”, in F. Albano Leoni e R. Giordano (eds.), Italiano Parlato. Analisi di un dialogo, pp. 213-229, Napoli, Liguori Editore
Imputation techniques for the reconstruction of missing interconnected data from higher Educational Institutions
No full textEducational Institutions data constitute the basis for several important analyses on the educational systems; however they often contain not negligible shares of missing values, for several reasons. We consider in this work the relevant case of the European Tertiary Education Register (ETER), describing the Educational Institutions of Europe. The presence of missing values prevents the full exploitation of this database, since several types of analyses that could be performed are currently impracticable. The imputation of artificial data, reconstructed with the aim of being statistically equivalent to the (unknown) missing data, would allow to overcome these problems. A main complication in the imputation of this type of data is given by the correlations that exist among all the variables. We propose several imputation techniques designed to deal with the different types of missing values appearing in these interconnected data. We use these techniques to impute the database. Moreover, we evaluate the accuracy of the proposed approach by artificially introducing missing data, by imputing them, and by comparing imputed and original values. Results show that the information reconstruction does not introduce statistically significant changes in the data and that the imputed values are close enough to the original values
Energy refurbishment of the general physiology institute at Sapienza university campus
No full textThe energy requalification of the existing building heritage is one of the pillars European Union energy policy. A large part of the building heritage was built without taking into consideration the problem of energy consumption. With the aim of energy efficiency and energy savings in electrical uses, there are wide and diversified possibilities for improvement, including interventions on the building envelope and on the systems, with the introduction, where possible, of renewable energy sources. In this context, the redevelopment of historic buildings constitutes an important challenge, which involves both historical-artistic aspects and technological aspects relating to the improvement of energy efficiency and comfort. A critical analysis of every possibility is essential to preserve the balance between efficiency and architecture. The purpose of the study is the energy retrofitting of the Institute of General Physiology located within the "Sapienza" University campus. The proposed interventions include the renovation of the whole building envelope, investigated by thermographic surveys, and the installation of new heating and cooling systems. The results were analysed to identify the best intervention for a sustainable energy renovation of the historic building, taking into account the preservation of its architectural values and making it suitable for modern use
A weighted surface-depth gradient method for the solution of the 2D shallow water equations
No full textThe two dimensional shallow water equations (SWE) are currently accepted as a mathematical basis for the study of several rapidly varying flows, such as those induced by dam breaking or embankment failure. Among the many methodologies available for the numerical integration of SWE, the finite volume MUSCL-Hancock cell-centred schemes are nowadays frequently used. These schemes should also include a robust and efficient treatment of the bottom source term in order to track the wetting and drying fronts and to preserve the static condition of a quiescent fluid over an irregular topography (C–property).
In particular the Surface Gradient Method (SGM – Zhou et al. 2001) computes water depth at the intercells from the extrapolation of the water surface level and introduces the bottom slope source term through a centred unsplit discretization; it can satisfy the C-property on a Cartesian grid even on irregular topographies, but it is not efficient in tracking wetting and
drying fronts. On the other hand, many schemes that evaluate water depth at the cell interfaces through the extrapolation of the same conserved variable (Depth Gradient Method, DGM) and
perform the splitting of the bed slope source term, do not satisfy the C-property, but are robust and stable near moving boundaries. In this paper a Weighted Surface-Depth Gradient Method, capable of preserving the good capabilities of the previously mentioned methods, is proposed. In the framework of the SGM scheme, the water depth at cell interfaces is estimated through a weighted average of the boundary extrapolated values deriving from MUSCL DGM and SGM reconstructions. The weight parameter is evaluated on the basis of the local Froude number through a formulation that allows a smooth transition between a fully SGM and a fully DGM treatment. The numerical scheme is validated through the application to some reference test cases whose exact solution is available in literature. The first set of tests concerns 1D steady flows on a steep parabolic bump in a rectangular frictionless channel (Liska & Wendroff 1998); the
second deals with two exact solutions (Thacker 1981) related to the periodic motion of a volume of water in a frictionless basin whose shape is a parabola of revolution. In all the tests the results obtained by the application of the Weighted Surface-Depth Gradient Method are better or, at least, equal to those obtained by the SGM or DGM schemes
L’evoluzione dell’attività condivisa nel secondo anno di vita: interventi materni e risposte del bambino
No full textL'attività condivisa madre-bambino nel secondo anno di vita: interventi materni e risposte del bambino
No full text- …
