Search results for "programming."
showing 10 items of 3035 documents
Semi-Regular Triangle Remeshing: A Comprehensive Study
2014
Semi-regular triangle remeshing algorithms convert irregular surface meshes into semi-regular ones. Especially in the field of computer graphics, semi-regularity is an interesting property because it makes meshes highly suitable for multi-resolution analysis. In this paper, we survey the numerous remeshing algorithms that have been developed over the past two decades. We propose different classifications to give new and comprehensible insights into both existing methods and issues. We describe how considerable obstacles have already been overcome, and discuss promising perspectives.
Analogy Construction and Success in Mathematics and Science Problem-solving: a Study with Secondary Students // Construcción de analogías y éxito en …
2012
We conducted an empirical study to analyse the association between students’ perception of surface and structural analogies between problems, and their algebraic success. Different surface and structural relationships between one ‘source’ problem and ‘target’ problems were considered. We also considered high (daily life) and low (scientific) familiarity contexts. Algebraic success was measured by the equations selected to solve each problem. Similarities and differences between problems were explicitly asked to students. Results showed a significant correlation between detecting the correct structural relation between problems and selecting the correct equations to solve them. Low familiari…
Multiresolution Analysis for Meshes with Appearance Attributes
2005
International audience; We present a new multiresolution analysis framework for irregular meshes with attributes based on the lifting scheme. We introduce a surface prediction operator to compute the detail coefficients for the geometry and the attributes of the model. Attribute analysis gives appearance information to complete the geometrical analysis of the model. A set of experimental results are given to show the efficiency of our framework. We present two applications to adaptive visual-ization and denoising.
Metal clusters on an inert surface: A simple model
1997
The shapes of metal clusters (with 2 to 14 valence electrons) on an inert surface are studied with a simple model based on the ultimate jellium model. It is shown that within certain approximations the surface-cluster interaction can be described with an external potential in the Kohn-Sham method. No restrictions for the cluster geometry are imposed. The results show that depending on the strength of the interaction and on the size of the cluster, the ground state is either planar or three-dimensional, but in many cases both geometries are stable and there is a marked energy barrier between them. The results agree qualitatively with ab initio calculations of Na clusters on a NaCl(100) surfa…
Thermodynamics of Nanoparticles: Experimental Protocol Based on a Comprehensive Ginzburg-Landau Interpretation
2014
MATERIAUX+SMR:SDA; The effects of surface and interface on the thermodynamics of small particles require a deeper understanding. This step is crucial for the development of models that can be used for decision-making support to design nanomaterials with original properties. On the basis of experimental results for phase transitions in compressed ZnO nanoparticles, we show the limitations of classical thermodynamics approaches (Gibbs and Landau). We develop a new model based on the Ginzburg-Landau theory that requires the consideration of several terms, such as the interaction between nanoparticles, pressure gradients, defect density, and so on. This phenomenological approach sheds light on …
Near-surface defect profiling with slow positrons: Argon-sputtered Al(110).
1985
We report on slow-positron measurements of atomic defect distribution near a solid surface. Defects are produced by argon-ion bombardment of an Al(110) surface in ultrahigh vacuum. Defect profiles have a typical width of 15–25 Å and contain a broader tail extending to 50–100 Å. The defect density at the outermost atomic layers saturates at high argon fluences to a few atomic percent, depending on sputtering conditions. Defect production rate at >1 keV Ar+ energies is typically 1–5 vacancy-interstitial pairs per incident ion. Molecular-dynamics simulations of the collision cascade predict similar defect distributions. Peer reviewed
Multiresolution Analysis for Irregular Meshes
2003
International audience; The concept of multiresolution analysis applied to irregular meshes has become more and more important. Previous contributions proposed a variety of methods using simplification and/or subdivision algorithms to build a mesh pyramid. In this paper, we propose a multiresolution analysis framework for irregular meshes with attributes. Our framework is based on simplification and subdivision algorithms to build a mesh pyramid. We introduce a surface relaxation operator that allows to build a non-uniform subdivision for a low computational cost. Furthermore, we generalize the relaxationoperator to attributes such as color, texture, temperature, etc. The attribute analysis…
The range of non-surjective convolution operators on Beurling spaces
1996
AbstractLet μ ≠ 0 be an ultradistribution of Beurling type with compact support in the space . We investigate the range of the convolution operator Tμ on the space of non-quasianalytic functions of Beurling type associated with a weight w, in the case the operator is not surjective. It is proved that the range of TM always contains the space of real-analytic functions, and that it contains a smaller space of Beurling type for a weight σ ≥ ω if and only if the convolution operator is surjective on the smaller class.
Sustainable European fishery and the Friend of the Sea scheme: tools to achieve sustainable development in the fishery sector
2015
This paper investigates the role of the Friend of the Sea (FOS) scheme as a market tool for sustainable competitive advantage. To capture this effect, we apply a theoretical framework based on the stakeholder theory (SHT) and the natural-resource-based view (NRBV) to two case studies each in Italy and Spain. Our model allows us to explain the main factors determining an effective and competitive sustainable business model in the fishery sector. The results confirm the relevant influence of market forces in acquiring FOS certification and the role of the same as a counterpart to state authority.
Bildning as a Central Concept in the Cultural Policy of the Swedish Government : From Arthur Engberg to Alice Bah Kuhnke
2015
This article explores bildning as a central concept in the development of the explicit cultural policy of the Swedish government. It takes its point of departure in how the concept of bildning was interpreted by Arthur Engberg, the minister responsible for cultural policy in the Social Democrat governments 1932–1939. In his interpretation bildning was liked both to upholding the high arts and the national culture and to the idea of re-invigorating these through cultural policy and education. The article continues by looking at the role and the interpretations of this concept in the later government reports and government bills aiming to cover the entirety of Swedish cultural policy, i.e. th…