Search results for "Computer Graphics"
showing 10 items of 530 documents
Chebyshev’s Method on Projective Fluids
2020
We demonstrate the acceleration potential of the Chebyshev semi-iterative approach for fluid simulations in Projective Dynamics. The Chebyshev approach has been successfully tested for deformable bodies, where the dynamical system behaves relatively linearly, even though Projective Dynamics, in general, is fundamentally nonlinear. The results for more complex constraints, like fluids, with a particular nonlinear dynamical system, remained unknown so far. We follow a method describing particle-based fluids in Projective Dynamics while replacing the Conjugate Gradient solver with Chebyshev’s method. Our results show that Chebyshev’s method can be successfully applied to fluids and potentially…
Graph cut-based method for segmenting the left ventricle from MRI or echocardiographic images
2017
International audience; In this paper, we present a fast and interactive graph cut method for 3D segmentation of the endocardial wall of the left ventricle (LV) adapted to work on two of the most widely used modalities: magnetic resonance imaging (MRI) and echocardiography. Our method accounts for the fundamentally different nature of both modalities: 3D echocardiographic images have a low contrast, a poor signal-to-noise ratio and frequent signal drop, while MR images are more detailed but also cluttered and contain highly anisotropic voxels. The main characteristic of our method is to work in a 3D Bezier coordinate system instead of the original Euclidean space. This comes with several ad…
A systematic comparison of kinetic modelling methods generating parametric maps for [11C]-(R)-PK11195
2006
[(11)C]-(R)-PK11195 is presently the most widely used radiotracer for the monitoring of microglia activity in the central nervous system (CNS). Microglia, the resident immune cells of the brain, play a critical role in acute and chronic diseases of the central nervous system and in host defence against neoplasia. The purpose of this investigation was to evaluate the reliability and sensitivity of five kinetic modelling methods for the formation of parametric maps from dynamic [(11)C]-(R)-PK11195 studies. The methods we tested were the simplified reference tissue model (SRTM), basis pursuit, a simple target-to-reference ratio, the Logan plot and a wavelet based Logan plot. For the reliabilit…
Coupling Mechanics of Antikythera Gearwheels
2012
This paper discusses the gear coupling mechanics of the ancient Antikythera mechanism, among whose distinctive characteristics was the triangular shaping of the teeth. The engagement of the tooth pairs is analyzed in detail, estimating the temporal variation of the speed ratio due to the back and forth shifting of the relative instant center. The admissibility of the theoretical contact points is carefully checked, and the magnitude of the successive tooth collisions is calculated together with the energy losses arising from the particular nature of the coupling. Some interesting results are that only one tooth pair turns out to be active at each time instant and the real path may belong on…
A GPU-Based Multi-agent System for Real-Time Simulations
2010
The huge number of cores existing in current Graphics Processor Units (GPUs) provides these devices with computing capabilities that can be exploited by distributed applications. In particular, these capabilites have been used in crowd simulations for enhancing the crowd rendering, and even for simulating continuum crowds. However, GPUs have not been used for simulating large crowds of complex agents, since these simulations require distributed architectures that can support huge amounts of agents. In this paper, we propose a GPU-based multi-agent system for crowd simulation. Concretely, we propose the use of an on-board GPU to implement one of the main tasks that a distributed server for c…
Old Gibellina: the map, the world, the Aleph
2019
The present contribution intends to propose an epistemological reflection on the links and relationships that interweave the map, cultural heritage, landscape and places. I have identified an interpretative horizon that intersects the scientific geographic debate with the literary subject and proposed a specific reading of the site of Old Gibellina in Sicily, Italy, where reality and representation seem to converge. In 1968, Gibellina was razed to the ground by an earthquake. Then the site of Old Gibellina was covered by the ‘Grande Cretto’: the work of Land Art made by the artist Alberto Burri. In my perspective, the Cretto represents a unique place: it is a full-size map, it is landscape…
Jews under Islam in early modern Morocco in travel chronicles
2020
This paper addresses the relationship between the ideological and legal structures that discriminated against Jews in early modern Morocco and its reflection in social practices. The study shows th...
The development and validation of the Business Cultural Intelligence Quotient
2016
Purpose– The purpose of this paper is to present a new instrument for measuring cultural intelligence in the business context (BCIQ).Design/methodology/approach– The paper describes the process of the conceptualization of the model and the development of the instrument, the sample, as well as the validation of the instrument. Directions on the use of the instrument and future research are discussed.Findings– The instrument shows good psychometric properties and good predictive power and outperforms other publicly available CQ measures on a number of dimensions.Originality/value– The unique features and advantages of the present instrument are as follows: first, a refined factor structure co…
Virtual Acoustic Rendering in Old Spaces: Application to an Early-Modern Theatre in València, “L’Olivera”
2018
The application of the VR to the renderization of ancient and lost buildings is one important topic in the cultural heritage field nowadays. Moreover, the addition of other senses apart from the graphical view, increases the sensation of immersion in a virtual application. The aim of this paper is to show the work on a virtual acoustic system, based on Unity, FMOD and Csound. This system has been implemented to render binaural auralizations and has been applied to the renderization of an old and lost theatre in Valencia (Spain). This theatre was firstly build in the 16th century, and rebuilt several times until the 18th century. It has been modelled from ancient documents. The auralization …
Definition of a Model-Based Detector of Curvilinear Regions
2007
This paper describes a new approach for detection of curvilinear regions. These features detection can be useful for any matching based algorithm such as stereoscopic vision. Our detector is based on curvilinear structure model, defined observing the real world. Then, we propose a multi-scale search algorithm of curvilinear regions and we report some preliminary results.