Search results for "computer graphic"
showing 10 items of 530 documents
MESH COMPARISON USING ATTRIBUTE DEVIATION METRIC
2004
We propose a mesh comparison method using a new attribute deviation metric. The considered meshes contain geometrical and appearance attributes (material color, texture, temperature, etc.). The proposed deviation metric computes local differences between the attributes of two meshes. A mesh comparison assessment can be done easily and quickly using this metric. The techniques proposed are applicable in a number of ways, e.g. 3D matching and registration, and the example described in the paper is the simplification of a surface by iteratively reducing its complexity according to an error metric. The results are presented showing the success of the algorithm through comparisons with other me…
A general 4th-order PDE method to generate Bézier surfaces from the boundary
2006
In this paper we present a method for generating Bezier surfaces from the boundary information based on a general 4th-order PDE. This is a generalisation of our previous work on harmonic and biharmonic Bezier surfaces whereby we studied the Bezier solutions for Laplace and the standard biharmonic equation, respectively. Here we study the Bezier solutions of the Euler-Lagrange equation associated with the most general quadratic functional. We show that there is a large class of fourth-order operators for which Bezier solutions exist and hence we show that such operators can be utilised to generate Bezier surfaces from the boundary information. As part of this work we present a general method…
Boolean operations with implicit and parametric representation of primitives using R-functions
2005
We present a new and efficient algorithm to accurately polygonize an implicit surface generated by multiple Boolean operations with globally deformed primitives. Our algorithm is special in the sense that it can be applied to objects with both an implicit and a parametric representation, such as superquadrics, supershapes, and Dupin cyclides. The input is a constructive solid geometry tree (CSG tree) that contains the Boolean operations, the parameters of the primitives, and the global deformations. At each node of the CSG tree, the implicit formulations of the subtrees are used to quickly determine the parts to be transmitted to the parent node, while the primitives' parametric definition …
Entire reflective object surface structure understanding based on reflection motion estimation
2015
An sub-segmentation method for the reflective surface structure understanding.The use of reflection motion features as spatiotemporal coherence for video segmentation.Straightforward implementation.A building block for object recognition. The presence of reflection on a surface has been a long-standing problem for object recognition since it brings negative effects on object's color, texture and structural information. Because of that, it is not a trivial task to recognize the surface structure affected by the reflection, especially when the object is entirely reflective. Most of the cases, reflection is considered as noise. In this paper, we propose a novel method for entire reflective obj…
La Responsabilidad Social de la Educación Superior como Bien Común. Concepto y desafíos
2018
Este artículo atiende al planteamiento de la Unesco de considerar como bien común a la Educación Superior, en un momento en que las Instituciones de Educación Superior están inmersas en procesos caracterizados por una progresiva mercantilización del conocimiento que condiciona el acceso a la financiación por posicionamiento en rankings internacionales, poniendo en riesgo el objeto de contribuir a un desarrollo sostenible en sus contextos. Mediante un particular análisis de aspectos relacionados con la Responsabilidad Social y la relación con los grupos de interés, se realiza una contribución a la reflexión teórica y a los desafíos para conceptualizar la Educación Superior como un bien común.
Another defence of enumerated types
1991
I claim that enumerations, while of course not strictly necessary, are an elegant and useful facility in modern programming languages. I try to show that arguments recently given against them are weak at best and bogus a t worst, for general-purpose programming. Some related issues on types in programming languages are touched as well. These make it even more questionable whether Oberon marks progress or regress in language design.
A Viscoelastic Model for the Long-Term Deflection of Segmental Prestressed Box Girders
2017
Most of segmental prestressed concrete box girders exhibit excessive multidecade deflections unforeseeable by past and current design codes. To investigate such a behavior, mainly caused by creep and shrinkage phenomena, an effective finite element (FE) formulation is presented in this article. This formulation is developed by invoking the stationarity of an energetic principle for linear viscoelastic problems and relies on the Bazant creep constitutive law. A case study representative of segmental prestressed concrete box girders susceptible to creep is also analyzed in the article, that is, the Colle Isarco viaduct. Its FE model, based on the aforementioned energetic formulation, was succ…
A 3D REWORKING OF THE URBAN TRANSFORMATIONS OF PALERMO IN RECENT HISTORY FOR A HYPOTHESIS OF A "CITY MUSEUM" BASED ON DIGITAL VISUALIZATIONS
2021
Abstract. The objective that drives this research is given by a multitude of information which, in addition to the contribution of technology, allows us to study, analyze, verify and remodel the sites, monuments and evolutions of the city through graphic processes of perspective restitution that start from the analysis of historical photos. The drawing methods, the digital graphic rendering and through the aid of geometric techniques, contribute to the reconstruction of projects and architectures that are now lost, this is possible thanks to the methods of perspective, axonometry and three-dimensional restitution.This remarkable photographic heritage belonging to Palermo, but also to any ot…
In vivo evaluation of three-dimensional of volumetric changes using a CAD/CAM chair-side system : technical procedure
2017
An intraoral digital scanner in combination with specialized three-dimensional surface analysis software monitors volumetric changes to soft tissues or dental restorations. This technology can evaluate the success of a specific technique or medium- or long-term clinical outcomes in both clinical and research situations. This article describes how this technology was used to provide immediate chair-side data analysis without the help of specialized laboratory support. Key words:Intraoral scanner, CAD-CAM, best fit-method, surface tessellation language.
Processes of Reflection in the Teaching and Learning Research Lab: Effects of Reflecting on Classroom Actions
2021
The ability to reflect on teaching is crucially important for the professionalization of trainee teachers. The fostering of reflection processes – by means of the systematic analysis of one’s own and others’ teaching from subject-specific, methodological, and educational science perspectives – plays a central role in a continuing and consecutive two-semester teacher training seminar concept at the University of Mainz. This paper explores the different effects of reflection on teaching on the basis of a quasi-experimental pre-post test design. Additionally, it shows how systematic reflection on teaching affects the students’ subjective experience of competence as well as the extent the semin…