Search results for "Graphics"
showing 10 items of 1223 documents
Approximation Algorithms for Multicoloring Planar Graphs and Powers of Square and Triangular Meshes
2006
A multicoloring of a weighted graph G is an assignment of sets of colors to the vertices of G so that two adjacent vertices receive two disjoint sets of colors. A multicoloring problem on G is to find a multicoloring of G. In particular, we are interested in a minimum multicoloring that uses the least total number of colors. The main focus of this work is to obtain upper bounds on the weighted chromatic number of some classes of graphs in terms of the weighted clique number. We first propose an 11/6-approximation algorithm for multicoloring any weighted planar graph. We then study the multicoloring problem on powers of square and triangular meshes. Among other results, we show that the infi…
On the Use of GPU for Accelerating Communication-Aware Mapping Techniques
2015
Different communication-aware mapping techniques were proposed in recent years for improving the performance of distributed systems based on both, off-chip and on-chip networks. Some of these proposals were based on heuristic search for finding pseudo-optimal assignments of tasks and processing elements. However, the technology integration improvements have allowed a significant increase in the number of network nodes, requiring the acceleration of the heuristic search. In this paper, we propose a comparative study of the local search method used in a communication-aware mapping technique, when implemented on different parallel architectures. We compare the performance provided by a version…
Estimation of Purkinje trees from electro-anatomical mapping of the left ventricle using minimal cost geodesics
2015
The electrical activation of the heart is a complex physiological process that is essential for the understanding of several cardiac dysfunctions, such as ventricular tachycardia (VT). Nowadays, patient-specific activation times on ventricular chambers can be estimated from electro-anatomical maps, providing crucial information to clinicians for guiding cardiac radio-frequency ablation treatment. However, some relevant electrical pathways such as those of the Purkinje system are very difficult to interpret from these maps due to sparsity of data and the limited spatial resolution of the system. We present here a novel method to estimate these fast electrical pathways from the local activati…
Special track on Geometric Constraints and Reasoning
2008
Geometric Computing and Reasoning (GCR) aims at emphasizing recent trends in the domain of geometric constraint solving and automated, or computer aided deduction in geometry. This year sees the third edition of this technical track of SAC.
Hyperboloid and Parabolid in Orthogonal Axonometric
2012
This paper presents the issue of a long research on the representation of the complex surface in descriptive geometry. The ability to use the different techniques of representation aims to achieve results that you didn’t image before. In Palermo University, at the Engineering School, the researcher involved the study on the simplify of the so elaborated way to represent the geometry and its applications in architecture buildings and engineering implants. We just report below the application methods to represent two of the most used quadric surfaces in the practice of buildings. We are talking about Hyperboloid and Paraboloid quadric surface represented in axonometric projecting. This method…
Socio-demographic characteristics associated with emotional and social loneliness among older adults.
2021
Abstract Background International studies provide an overview of socio-demographic characteristics associated with loneliness among older adults, but few studies distinguished between emotional and social loneliness. This study examined socio-demographic characteristics associated with emotional and social loneliness. Methods Data of 2251 community-dwelling older adults, included at the baseline measure of the Urban Health Centers Europe (UHCE) project, were analysed. Loneliness was measured with the 6-item De Jong-Gierveld Loneliness Scale. Multivariable logistic regression models were used to evaluate associations between age, sex, living situation, educational level, migration background…
Space and Light, Towards an Interactive Simulation of Lighting
2003
International audience; Une image est une vue, à un instant donné, de l'équilibre lumineux présent dans une scène. Cet équilibre résulte d'un système complexe où l'énergie provenant des sources est re-distribuée dans l'espace par les matériaux appliqués aux formes. Si cet équilibre est perturbé par une modification des conditions lumineuses, l'image précédente n'est plus valide. En cela elle ne représente qu'un instant d'un lieu et non le lieu lui même. Nous proposons ici une approche pour la simulation interactive de l'éclairage dans une scène complexe. Une application à cette étude étant la production d'images vivantes et confondantes dans le cadre de la réalité augmentée.
Virtual reality school for children with learning difficulties
2005
This paper describes the process starting from the identification of educational needs of children with learning difficulties to the design of a fully interactive virtual school, where it is possible to learn about the physical and social world. The fundamentals of this design are the exclusive advantages that Real Time Graphics offer for developing tools in which children can learn while playing. This development has been done in the framework of a strongly-funded project by the Spanish Government. This ongoing project is in its final stage of development and will produce tools which are valid both for special and mainstream education, ready to be used and tested over final users.
GPU-laskennan optimointi
2013
Näytönohjaimet, grafiikkasuorittimet, tarjoavat rinnakkaisen laskennan alustan, jossa voidaan suorittaa ohjelmakoodia satojen ydinten toimesta. Tämä alusta mahdollistaa matemaattisesti työläiden ongelmien ratkaisemisen tehokkaasti. Grafiikkasuorittimen rinnakkainen suoritusympäristö kuitenkin eroaa suuresti tietokoneen suorittimen peräkkäisestä suoritusympäristöstä. Ongelmien ratkaisemiseksi tehokkaasti rinnakkaisympäristössä on noudettava ohjelmointimenetelmiä, jotka soveltuvat erityisesti rinnakkaisympäristöön. Tässä työssä tarkastellaan rinnakkaisen laskennan perusteita, miten erilaiset ohjelmointimenetelmät vaikuttavat ohjelman suoriutumiseen grafiikkasuorittimella sekä miten voidaan sa…
Design of a Generic 3-D Scene Generator for Passive Optical Missions and Its Implementation for the ESA’s FLEX/Sentinel-3 Tandem Mission
2018
During the design phase of a satellite mission, end-to-end mission performance simulator (E2ES) tools allow scientists and engineers evaluating the mission concept, consolidating system technical requirements and analyzing the suitability of the implemented technical solutions and data processing algorithms. The generation of synthetic scenes is one of the core parts of an E2ES, providing scenes (ground truth) as would be observed by satellite instruments and used as reference against simulated retrieved mission products. An appropriate generation of the scene also allows assessing the performance of the ground data processing chain replacing real instrument data before the mission is in or…