1,721,090 research outputs found
Metodo implementato mediante computer per la rimappatura di una texture di un oggetto grafico tridimensionale
No full textWavelet–Fourier CORSING techniques for multidimensional advection–diffusion–reaction equations
Full text linkWe present and analyze a novel wavelet–Fourier technique for the numerical treatment of multidimensional advection–diffusion–reaction equations based on the COmpRessed SolvING (CORSING) paradigm. Combining the Petrov–Galerkin technique with the compressed sensing approach the proposed method is able to approximate the largest coefficients of the solution with respect to a biorthogonal wavelet basis. Namely, we assemble a compressed discretization based on randomized subsampling of the Fourier test space and we employ sparse recovery techniques to approximate the solution to the partial differential equation (PDE). In this paper we provide the first rigorous recovery error bounds and effective recipes for the implementation of the CORSING technique in the multidimensional setting. Our theoretical analysis relies on new estimates for the local a-coherence, which measures interferences between wavelet and Fourier basis functions with respect to the metric induced by the PDE operator. The stability and robustness of the proposed scheme are shown by numerical illustrations in the one-, two- and three-dimensional cases
A dimension-reduction model for brittle fractures on thin shells with mesh adaptivity
No full textIn this paper, we derive a new 2D brittle fracture model for thin shells via dimension reduction, where the admissible displacements are only normal to the shell surface. The main steps include to endow the shell with a small thickness, to express the three-dimensional energy in terms of the variational model of brittle fracture in linear elasticity, and to study the L-limit of the functional as the thickness tends to zero. The numerical discretization is tackled by first approximating the fracture through a phase field, following an Ambrosio-Tortorelli like approach, and then resorting to an alternating minimization procedure, where the irreversibility of the crack propagation is rigorously imposed via an inequality constraint. The minimization is enriched with an anisotropic mesh adaptation driven by an a posteriori error estimator, which allows us to sharply track the whole crack path by optimizing the shape, the size, and the orientation of the mesh elements. Finally, the overall a..
Influence of zinc ions on protein secretion in a heavy metal tolerant strain of the ericoid mycorrhizal fungus Oidiodendron maius.
No full text19th International Conference on Finite Elements in Flow Problems
No full textThis special issue presents contributions from the semi-plenary lecturers of the Nineteenth International Conference on Finite Elements in Flow Problems held in Rome, Italy, on 5–7 April 2017. The papers provide an overview of the current developments in the vanguard of finite-element methods in fluid dynamics and related areas, and cover a wide range of techniques, including model reduction, cut and immersed-boundary methods, space-time methods and isogeometric analysis, with applications spanning fluid-solid interaction, biology and biomechanics, and multi-phase flows
Le competenze interculturali negli adolescenti: il ruolo delle caratteristiche individuali e ambientali.
No full textGoing Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Hierarchical model reduction techniques for flow modeling in a parametrized setting
Full text linkIn this work we focus on two different methods to deal with parametrized partial differential equations in an efficient and accurate way. Starting from high fidelity approximations built via the hierarchical model reduction discretization, we consider two approaches, both based on a projection model reduction technique. The two methods differ for the algorithm employed during the construction of the reduced basis. In particular, the former employs the proper orthogonal decomposition, while the latter relies on a greedy algorithm according to the certified reduced basis technique. The two approaches are preliminarily compared on two-dimensional scalar and vector test cases
Molecular identification of root fungal associates in Orchis pauciflora Tenore
No full textThe terrestrial orchid, Orchis pauciflora Ten., growing in poor grassland and garrigue of Central Mediterranean region, is
local and rare and has been included in the red lists of several Italian regions. We investigated the diversity of fungal
associates in O. pauciflora adult plants collected in two protected areas of Tuscany (Central Italy). Genomic DNA was
extracted from mycorrhizal roots of 12 orchid plants and the fungal ITS were amplified and sequenced. Several fungal
associates, belonging to different taxa of basidiomycetes (Tulasnellaceae) and ascomycetes such as Leptodontidium, Exophiala
and Phialophora species, were recovered. The trophic role of these fungi and their impact on O. pauciflora growth and
conservation are discussed
- …
