117,414 research outputs found
Gli altri erano camerati, noi ci sentivamo fratelli
No full textIl volume, preceduto da una prefazione di Livia Cadei e da un'introduzione di Pierangelo Goffi, ripropone uno scritto di Lina Tridenti pubblicato nel 1966 per ringraziare don Luigi Pascoli e la madre che, durante la Resistenza, accolsero e nascosero Lina Tridenti, partigiana vicentina, assieme ai suoi compagni nella lotta clandestina.
Lo scritto testimonia il percorso di assunzione di responsabilità della giovane, assieme agli ideali che animarono la scelta di ribellione al fascismo e all'occupazione nazista
On the optimal -regularity for viscous Hamilton-Jacobi equations with subquadratic growth in the gradient
No full textThis paper studies a maximal -regularity property for nonlinear elliptic equations of second order with a zero-th order term and gradient nonlinearities having superlinear and sub-quadratic growth, complemented with Dirichlet boundary conditions. The approach is based on the combination of linear elliptic regularity theory and interpolation inequalities, so that the analysis of the maximal regularity estimates boils down to determine lower order integral bounds. The latter are achieved via a duality method, which exploits the regularity properties of solutions to stationary Fokker-Planck equations. For the latter problems, we discuss both global and local estimates. Our main novelties for the regularity properties of this class of nonlinear elliptic boundary-value problems are the treatment of equations with a zero-th order term together with the analysis of the end-point summability threshold , being the dimension of the ambient space and the growth of the first-order term in the gradient variable
Le colonie marine del fascismo. Il caso della "Principe di Piemonte" a Senigallia: le origini, l'impiego attuale, un progetto di riuso
No full textTransport equations with nonlocal diffusion and applications to Hamilton–Jacobi equations
No full textWe investigate regularity and a priori estimates for Fokker-Planck and Hamilton-Jacobi equations with unbounded ingredients driven by the fractional Laplacian of order sin(1/2,1). As for Fokker-Planck equations, we establish integrability estimates under a fractional version of the Aronson-Serrin interpolated condition on the velocity field and Bessel regularity when the drift has low Lebesgue integrability with respect to the solution itself. Using these estimates, through the Evans' nonlinear adjoint method we prove new integral, sup-norm and Hölder estimates for weak and strong solutions to fractional Hamilton-Jacobi equations with unbounded right-hand side and polynomial growth in the gradient. Finally, by means of these latter results, exploiting Calderón-Zygmund-type regularity for linear nonlocal PDEs and fractional Gagliardo-Nirenberg inequalities, we deduce optimal L^q-regularity for fractional Hamilton-Jacobi equations
Lipschitz regularity for viscous Hamilton-Jacobi equations with Lp terms
No full textWe provide Lipschitz regularity for solutions to viscous time-dependent Hamilton-Jacobi equations with right-hand side belonging to Lebesgue spaces. Our approach is based on a duality method, and relies on the analysis of the regularity of the gradient of solutions to a dual (Fokker-Planck) equation. Here, the regularizing effect is due to the non-degenerate diffusion and coercivity of the Hamiltonian in the gradient variable
On the Problem of Maximal Lq -regularity for Viscous Hamilton–Jacobi Equations
No full textIn this paper we prove a conjecture by P.-L. Lions on maximal regularity of Lq-type for periodic solutions to - Δ u+ | Du| γ= f in Rd, under the (sharp) assumption that q>dγ-1γ
Maximal Lq -Regularity for Parabolic Hamilton–Jacobi Equations and Applications to Mean Field Games
No full textIn this paper we investigate maximal Lq-regularity for time-dependent viscous Hamilton–Jacobi equations with unbounded right-hand side and superlinear growth in the gradient. Our approach is based on the interplay between new integral and Hölder estimates, interpolation inequalities, and parabolic regularity for linear equations. These estimates are obtained via a duality method à la Evans. This sheds new light on the parabolic counterpart of a conjecture by P.-L. Lions on maximal regularity for Hamilton–Jacobi equations, recently addressed in the stationary framework by the authors. Finally, applications to the existence problem of classical solutions to Mean Field Games systems with unbounded local couplings are provided
Corporate Social Responsibility and Investment Preferences of Tour Operators
No full textThis study examines the role of corporate social responsibility (CSR) in the investment preferences of tour operators through a discrete choice experiment conducted among tour operator managers worldwide. Stakeholder theory is used as a theoretical platform for explaining the role of CSR within the tour operators’ investment preferences. The findings indicate that, when making investment decisions, tour operators generally tend to balance the interests of the local community, employees and businesses, and to consider the effects of their investments on the local economy and the environment. However, empirical evidence indicates that tour operator’s investment preferences are moderated by three factors, namely: local government pressure, size of the investment, and tour operator profile. In particular, greater attention should be paid to high-scale investments, and to investments made by generalist tour operators if destinations want to preserve their distinctive sociocultural and natural assets and provide well-being to local communities
Fostering tourism destination competitiveness in developing countries: The role of sustainability
No full textThis study aims to test if sustainability influences tourism destination competitiveness in developing countries. The case study for the analysis is Brazil, where the enormous and unexploited potential for tourism makes sustainability a central issue in tourism development. Empirical results show that sustainability factors are positively associated with competitiveness indicators used as dependent variables in the regression model, thereby supporting the hypothesis that sustainability plays a key role in fostering tourism destination competitiveness. Tourism growth in developing countries has led to a number of environmental and socioeconomic problems. These results indicate that a new model of cleaner tourism that favorably affects economy, environment, and society is required. Some recommendations are provided based on empirical evidence to enable the developing countries to attain sustainable tourism development
Rethinking sustainability in the tour-operating industry: Worldwide survey of current attitudes and behaviors
No full textThis study aims to assess tour operators’ sustainability orientation and engagement and to determine whether variations among different tour operators exist, that is, from different continents, with different targets and dimensions. A survey among tour operators worldwide was conducted. A total of 204 answers were obtained with a worldwide coverage. Results affirm relatively high sustainability orientation and engagement and that the more sustainability-oriented the tour operators are, the more sustainability-engaged they are. Moreover, results show that smaller tour operators, specializing in nature and cultural tourism, and owning accommodation facilities are also highly engaged in sustainability. Significant differences are observed among regions, with higher engagement for African and Asian tour operators compared with European ones. This study proposes the development of a new approach to sustainability in this sector: by introducing corporate sustainability strategies, tour operators can maintain their economic capital while preserving natural and social capital
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