1,242 research outputs found
Grant Cardone International Sales Expert, Author & Coach
No full textGrant Cardone International Sales Expert, Author & Coach
Numerical schemes specially tuned for some evolutionary problems
No full textThe effective numerical integration of evolutionary problems arising from real-life applications requires the analysis of the characteristics of the phenomenon and of the corresponding mathematical model. The resulting numerical methods will therefore be able to reproduce the behavior of the analytical solution and to exploit the knowledge on the problem to reduce the computational effort. This approach has been developed for some classes of differential systems and for some classes of problems with memory modeled by integral or fractional equations.
Problems like advection-diffusion or reaction-diffusion problems are usually solved by a semidiscretization along space, which gives raise to (large) systems of ordinary differential systems characterized by a stiff part and a non-stiff one. IMEX methods treat implicitly the stiff part and explicitly the non-stiff one, in order to have strong stability properties and to reduce the computational cost. We introduce a class of IMEX general linear methods which have no coupling order conditions, do not suffer of the order reduction phenomenon thanks to the high stage order, and have optimal stability properties.
Periodic phenomena with memory, like the spread of seasonal diseases, are modeled by Volterra integral equations with periodic solution. Classical methods require a small stepsize to follow the oscillations.We apply the exponential fitting technique [8] to derive direct quadrature methods with parameters depending on an estimate of the frequency. The error is smaller than the error of classical methods, when periodic problems are treated; the numerical stability is not affected by the accuracy of the estimate of the frequency.
Fractional models can represent memory effects of natural processes and also the anomalous kinetics of some processes in physics, chemistry, pharmacokinetis. Here we focus on the numerical solution of time-fractional reaction-diffusion systems, by a spectral technique along time and a finite difference scheme along space, which are specially designed to reproduce the behavior of the analytical solution and to simplify the overall computation.
The results presented here have been obtained by various collaborations, with K. Burrage, R. D’Ambrosio, L.Gr. Ixaru, Z. Jackiewicz, B. Paternoster, A. Sandu, G. Santomauro, H. Zhang.
References
[1] Ascher, U.M., Ruuth, S.J., Spiteri, R.J. Implicit-explicit Runge-Kutta methods for timedependent partial differential equations. Appl. Numer. Math. 25, 151–167 (1997).
[2] Cardone, A., Jackiewicz, Z., Sandu, A., Zhang, H., Extrapolated implicit-explicit Runge-Kutta methods. Math. Model. Anal. 19, 18–43 (2014).
[3] Cardone, A., Jackiewicz, Z., Sandu, A., Zhang, H., Extrapolation-based implicit-explicit general linear methods. Numer. Algorithms 65, 377–399 (2014).
[4] Cardone, A., Jackiewicz, Z., Sandu, A., Zhang, H., Construction of highly stable implicit-explicit general linear methods, accepted for publication in Discrete Contin. Dyn. Systs.
[5] A. Cardone, L. Gr. Ixaru, and B. Paternoster, Exponential fitting direct quadrature methods for Volterra integral equations, Numer. Algorithms 55, no. 4, 467-480 (2010).
[6] A. Cardone, L.Gr. Ixaru, B. Paternoster, and G. Santomauro, Ef-gaussian direct quadrature methods for Volterra integral equations with periodic solution, Math. Comput. Simul., in press.
[7] V. Gafiychuk, B. Datsko, and V. Meleshko, Mathematical modeling of time fractional reaction-diffusion systems, J. Comput. Appl. Math. 220(1-2), 215-225 (2008).
[8] L.Gr. Ixaru, G. Vanden Berghe, (2004) Exponential Fitting. Kluwer Academic Publishers, Dordrecht.
[9] L. Pareschi, G. Russo, Implicit-explicit Runge-Kutta schemes and applications to hyperbolic systems with relaxation, J. Sci. Comput. 25(1-2), 129–155 (2005)
Il successo di EGA presso gli studiosi italiani / EGA’s success amongst Italian academics,
No full text[EN] Since a long time I have been convinced that EGA is the best architectural representation magazine – or maybe of all graphic representation ones – and it’s not a mistery. It is obvious that not everyone will share this oppinion and someone could get angry when I say it, but it is meditated oppinion, supported by irrefutable data, released from my personal relationship with the magazine and the colleagues who participate in it.[IT] Da molti anni sono convinto che EGA sia la migliore rivista di rappresentazione dell’architettura – se non addirittura di tutte quelle che si interessano di rappresentazione grafica – e non ne faccio mistero. È ovvio che non tutti condividono e qualcuno si arrabbia quando lo affermo, ma si tratta di opinione meditata, suffragata da dati inoppugnabili, svincolati dal mio personale rapporto con la rivista e i colleghi che la curano.Cardone, V. (2018). Il successo di EGA presso gli studiosi italiani. EGA. Revista de Expresión Gráfica Arquitectónica. 23(34):206-211. https://doi.org/10.4995/ega.2018.10852SWORD2062112334AMORUSO, G., 2018. El espacio ilusorio barroco en las perspectivas arquitectónicas de Girolamo Curti y Angelo Michele Colonna en el Palacio de la Ciudad de Bolonia, EGA Expresión Gráfica Arquitectónica, 33, pp. 78-89. https://doi.org/10.4995/ega.2018.10389Barba, S., Messina, B. (in charge of), 2005. Il disegno dei viaggiatori. Salerno: CUES.Bartolomei, C., Ippolito, A., 2015. Faros italianos entre geometría y simbolismo, EGA Expresión Gráfica Arquitectónica, 25, pp. 192-199. https://doi.org/10.4995/ega.2015.3679Borja Molero, A., Barba, S., Álvaro Tordesillas, A., 2016., Documentación del patrimonio cultural. Método basado en la fusión de técnicas fotogramétricas y de escaneado óptico de triangulación, EGA Expresión Gráfica Arquitectónica, 28, pp. 236-245. https://doi.org/10.4995/ega.2016.6308Cabezos Bernal, P., Rossi, A., 2017. Técnicas de musealización virtual. Los capiteles del Monasterio de San Cugat, EGA Expresión Gráfica Arquitectónica, 29, pp. 48-57. https://doi.org/10.4995/ega.2017.7340Calisi, D., Cianci, M.G., 2018. De lo virtual a lo real. Un modelo de madera para la reconstrucción filológica del barrio Alessandrino en la zona arqueológica central de Roma, EGA Expresión Gráfica Arquitectónica, 33, pp. 90-102. https://doi.org/10.4995/ega.2018.8924Capone, M., Nigro, E., 2017. Desde la geometría hasta la representación generativa. La búsqueda de una solución optimizada en el proyecto del Club Táchira (Caracas, 1955), E GA Expresión Gráfica Arquitectónica, 31, pp. 172-183.Cardone, V., 2002. Pedro Luis Escrivá: forma e funzione nel disegno delle fortificazioni, EGA Expresión Gráfica Arquitectónica, 7, pp. 36-47.Cardone, V., 2003. Pedro Luis Escrivá, ingegnere militare del Regno di Napoli. Salerno: CUES.Cardone, V., 2005. A proposito di nome, contenuti, programmi e prospettive per la nostra area culturale, EGA Expresión Gráfica Arquitectónica, 10, pp. 48-57. https://doi.org/10.4995/ega.2005.10329Cardone, V., 2017. Editoriale, diségno, n.1, luglio-dicembre 2017, pp. 5-8.Cipriani, L., Fantini, F., Bertacchi, S., 2015. El color en las piedras y en los mosaicos de Rávena: nuevas imágenes de los monumentos antiguos a través de la fotogrametría no convencional de última generación, EGA Expresión Gráfica Arquitectónica, 26, pp. 190-201. https://doi.org/10.4995/ega.2015.4052De Sanctis, A., Fortunato, G., Zappani, A.A., 2017. Nuevos levantamientos y documentos de archivo para el conocimiento de los bienes arquitectónicos: la construcción en el siglo xvii de un nuevo vestíbulo en el Convento- Santuario de San Francisco de Paula (Paula- Italia), EGA Expresión Gráfica Arquitectónica, 30, pp. 118-129. https://doi.org/10.4995/ega.2017.7835Fantini, F., 2012. Modelos con nivel de detalle variable realizados mediante un levantamiento digital aplicados a la arqueología, EGA Expresión Gráfica Arquitectónica, 19, pp. 306-317. https://doi.org/10.4995/ega.2012.1383Gombrich, E.H., 1993. Historia del arte y psicología en Viena, hace cincuenta años, EGA Expresión Gráfica Arquitectónica, 1, pp. 38-41.Leserri, M., Rossi, G., 2013. Arquitecturas de piedra seca, un levantamiento problemático, EGA Expresión Gráfica Arquitectónica, 22, pp. 184-195. https://doi.org/10.4995/ega.2013.1532Maestri, D., 1993. Axonometría, dibujo y arquitectura, EGA Expresión Gráfica Arquitectónica, 1, pp. 99-108.Rossi, A., Palmero, L., DeGregorio, S., 2018. El análisis de la forma en el diseño arquitectónico: desde el proyecto a la ejecución, EGA Expresión Gráfica Arquitectónica, 32, pp. 186-197. https://doi.org/10.4995/ega.2018.894
Analisi Sperimentale delle Prestazioni e delle Emissioni di un Motore Diesel Alimentato con Miscele di Biocombustibile e Gasolio
No full textAnalisi Sperimentale delle Prestazioni e delle Emissioni di un Motore Diesel Alimentato con Miscele di Biocombustibile e Gasolio
No full text
L'identità dei Campi Flegrei
No full textIl libro è il frutto di una ricerca sui Campi Flegrei, condotta sulla base di fonti storiche, letterarie, economiche, iconografiche, molte delle quali inedite, nonchè di un corposo repertorio di rilievi architettonici e ambientali
Low surface brightness galaxies rotation curves in the low energy limit of R**n gravity: no need for dark matter?
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