14 research outputs found

    A progressive refinement approach for the visualisation of implicit surfaces

    Get PDF
    Visualising implicit surfaces with the ray casting method is a slow procedure. The design cycle of a new implicit surface is, therefore, fraught with long latency times as a user must wait for the surface to be rendered before being able to decide what changes should be introduced in the next iteration. In this paper, we present an attempt at reducing the design cycle of an implicit surface modeler by introducing a progressive refinement rendering approach to the visualisation of implicit surfaces. This progressive refinement renderer provides a quick previewing facility. It first displays a low quality estimate of what the final rendering is going to be and, as the computation progresses, increases the quality of this estimate at a steady rate. The progressive refinement algorithm is based on the adaptive subdivision of the viewing frustrum into smaller cells. An estimate for the variation of the implicit function inside each cell is obtained with an affine arithmetic range estimation technique. Overall, we show that our progressive refinement approach not only provides the user with visual feedback as the rendering advances but is also capable of completing the image faster than a conventional implicit surface rendering algorithm based on ray casting

    Interactive ray shading of FRep objects

    Get PDF
    In this paper we present a method for interactive rendering general procedurally defined functionally represented (FRep) objects using the acceleration with graphics hardware, namely Graphics Processing Units (GPU). We obtain interactive rates by using GPU acceleration for all computations in rendering algorithm, such as ray-surface intersection, function evaluation and normal computations. We compute primary rays as well as secondary rays for shadows, reflection and refraction for obtaining high quality of the output visualization and further extension to ray-tracing of FRep objects. The algorithm is well-suited for modern GPUs and provides acceptable interactive rates with good quality of the results. A wide range of objects can be rendered including traditional skeletal implicit surfaces, constructive solids, and purely procedural objects such as 3D fractals

    doente idoso com delirium na UCI e familia

    Get PDF
    Mestrado, Enfermagem Médico Cirurgica - Pessoa Idosa, 2014, Escola Superior de Enfermagem de LisboaO delirium é uma manifestação de uma disfunção cerebral aguda frequente nos idosos internados nas Unidades de Cuidados Intensivos. Está definido no DSM-IV-TR como uma perturbação da consciência, atenção e perceção que se desenvolve num curto espaço de tempo, podendo apresentar flutuações ao longo do dia. O delirium tem ganho notoriedade nos últimos anos devido ao aumento da população idosa internada na UCI e à crescente tomada de consciência dos médicos e enfermeiros relativamente aos seus efeitos adversos que incluem: aumento do tempo de internamento na UCI e hospitalar, aumento da mortalidade e da morbilidade, declínio funcional e cognitivo, institucionalização e aumento de custos associados. A acrescentar, o facto de as suas manifestações serem extremamente perturbadoras para o doente, família e equipa de saúde. Os enfermeiros detêm um papel essencial na prevenção, identificação precoce e implementação de cuidados baseados na melhor evidência, de modo a limitar os efeitos do delirium, que muitas vezes se estendem ao período após a alta hospitalar. Efectuei um projeto com a finalidade de promover a melhoria da qualidade dos cuidados de enfermagem prestados à pessoa idosa com delirium e sua família, numa UCI de Neurocríticos. O envolvimento da equipa multidisciplinar na implementação de um instrumento de avaliação do delirium sensível e específico, bem como a uniformização dos cuidados adequados ao doente idoso com delirium e sua família, prezando a manutenção da sua autonomia e respeitando a sua dignidade, foram fundamentais para o desenvolvimento de boas práticas nos cuidados, com o fim de se atingir um nível de cuidados de enfermagem de excelênci

    Description des tâches avec un système interactif multiutilisateur et multimodal : Etude comparative de notations

    No full text
    International audienceMulti-user multimodal interactive systems involve multiple users who can use multiple interactionmodalities. Multi-user multimodal systems are becoming more prevalent, especially systems based on largeshared multi-touch surfaces or video game centers such as Wii or Xbox. In this article we address thedescription of the tasks with such interactive systems. We review existing notations for the description of taskswith a multi-user multimodal interactive system and focus particularly on tree-based notations. For elementarytasks (e.g. actions), we also consider the notations that describe multimodal interaction. The contribution isthen a comparison of existing notations based on a set of organized concepts. While some concepts are generalto any notation, other concepts are specific to human-computer interaction, or to multi-user interaction andfinally to multimodal interaction.De nombreux systèmes interactifs, professionnels ou grand public, permettent conjointementl’interaction multiutilisateur et multimodale. Un système interactif est multimodal lorsqu’un utilisateur peutinteragir avec le système par l’usage de plusieurs modalités d’interaction (en entrée ou en sortie) de façonparallèle ou non. Nous constatons que de plus en plus de systèmes multiutilisateurs ou collecticiels sontmultimodaux, comme ceux construits autour d’une surface interactive et les consoles de jeu de type Wii ouXbox. Nous traitons dans cet article de la description des tâches-utilisateur avec de tels systèmes interactifsmultiutilisateurs et multimodaux. Précisément, nous dressons un panorama des notations existantes permettantla description des tâches mono ou multi-utilisateur avec une attention particulière pour les notations à based’arbre de tâches. Nous focalisons aussi sur les tâches élémentaires ou actions mono/multi-modales del’utilisateur en considérant les notations de description de l’interaction multimodale. Pour cela, nousproposons une étude comparative d'un ensemble de notations de description selon une grille d’analyseregroupant des concepts généraux à l’interaction et des concepts propres à l’interaction multiutilisateur etmultimodale

    Relatório de atividades : 2013

    Get PDF
    Relatório de atividades referente ao ano de 2013 do Departamento de Ciências e Tecnologia - DCe

    Scientific History of Incipit in the period 2010-2016

    Get PDF
    Historial de la actividad científica y técnica del Instituto de Ciencias del Patrimonio (Incipit) del CSIC, basado en Santiago de Compostela, desde su fecha de creación (2010) hasta el año 2016. Se presentan la misión y las líneas de investigación del Incipit, centradas principalmente en el estudio de los procesos de patrimonialización y de valorización social del patrimonio cultural realizadas con una perspectiva transdisciplinar. Se relacionan las publicaciones, proyectos de investigación, actividades de ciencia pública, eventos de comunicación y productos de divulgación que su personal investigador ha producido a lo largo de estos años.General introduction to the Incipit. Presentation of the Research Line: Cultural Heritage Studies: Sub-Theme: Landscape Archaeology and Cultural Landscapes, Sub-theme: Heritagization Processes: Memory, Power and Ethnicity, Sub-theme: Socioeconomics of Cultural Heritage, Sub-theme: Archaeology of the Contemporary Past, Sub-theme: Material culture and formalization processes of cultural heritage. Scientific Contributions. Transfer of Knowledge. International Activities. Other Activities and Results. Scientific DisseminationN

    Real-Time Inverse Lighting for Augmented Reality Using a Dodecahedral Marker

    Get PDF
    Lighting is a major factor in the perceived realism of virtual objects, and thus lighting virtual objects so that they appear to be illuminated by real-world light sources - a process known as inverse lighting - is a crucial component to creating realistic augmented reality images. This work presents a new, real-time inverse lighting method that samples the light reflected off of a regular, twelve-sided (dodecahedral), 3D object to estimate the light direction of a scene's primary light source. Using the light sample results, each visible face of the dodecahedron is determined to either be in light or in shadow. One or more light vectors then are calculated for each face by either using the surface normal vector of the face as a light direction vector if the face is in light, or by reflecting the face's surface normal across the normal vector of every adjacent illuminated face in the case of shadowed faces. If the shadowed face is not adjacent to any illuminated faces, the normal vector is reversed instead. These light vectors then are averaged to produce a vector pointing to the primary light source in the environment. This method is designed with special consideration to ease of use for the user, requiring no configuration stages.Computer Scienc

    Parcerias logisticas: estudos de caso

    Get PDF
    O processo de globalização tem contribuído para o desenvolvimento da reestruturação das firmas, por vezes são necessárias alianças, o que implica alterações na cadeia de valor, sendo fundamentais novas formas de relacionamento interpessoal e de operação. Os Pólos Industriais representam a presença física de entidades em determinadas posições geográficas, responsáveis pelo desenvolvimento económico, tecnológico e social da região. Este trabalho de investigação tem como intuito geral verificar o contributo efetivo para o aumento de vantagem competitiva das firmas parceiras na logística e produção de componentes para o setor automóvel, tendo como estudo do caso Caetano Coatings Automotive. O estudo foi realizado no Pólo Industrial do Carregado, com base numa pesquisa empírica, cumulativamente com revisão da literatura inerente às parcerias em cluster no sector automóvel e várias visitas ao local. Para a realização deste objetivo foi utilizado o método do estudo do caso por permitir ao investigador através da observação direta e entrevista analisar fenómenos atuais. Tal recolha de dados demonstra que alterações de localização e o fator proximidade contribuem para aumento de competitividade do Pólo Industrial através da redução do espaço e tempo e consequentemente redução de custos e lead-time. Foram analisadas de forma comparativa o desenvolvimento das firmas que detinham e detêm parcerias no Pólo Industrial, tendo sido identificado de forma significativa as contribuições para o aumento da vantagem competitiva. Os resultados obtidos evidenciam fatores que contribuem para novos tipos de relacionamento e aumento de vantagem competitiva foi devida à deslocalização das firmas parceiras integradas no Pólo Industrial.The globalization process has contributed to the development of the restructuring of firms, sometimes alliances are necessary, which implies changes in the value chain, with key new forms of interpersonal and operation. Industrial Poles represent the physical presence of entities in certain geographic locations, responsible for economic development, technological and social region. This research has as objective to verify the overall effective contribution to increasing competitive advantage of firms partner in logistics and production of components for the automotive sector, with the case study Caetano Automotive Coatings. The study was conducted in the Industrial Pole of the loaded, based on empirical research, cumulatively with literature review inherent in cluster partnerships in the automotive sector and several site visits. To accomplish this goal we used the case study method because it allows the researcher through direct observation and interviews to analyze current events. This collection of data shows those changes in location and proximity factor contributing to increased competitiveness of the industrial pole through the reduction of space and time and consequently reduce costs and lead time Were analyzed in a comparative way the development of firms that held and holds partnerships in the Industrial Pole, has been identified as significant contributions to increasing the competitive advantage. The results show factors that contribute to new relationships and increased competitive advantage was due to the relocation of firms integrated partner in the Industrial Pole

    Realistic reconstruction and rendering of detailed 3D scenarios from multiple data sources

    Get PDF
    During the last years, we have witnessed significant improvements in digital terrain modeling, mainly through photogrammetric techniques based on satellite and aerial photography, as well as laser scanning. These techniques allow the creation of Digital Elevation Models (DEM) and Digital Surface Models (DSM) that can be streamed over the network and explored through virtual globe applications like Google Earth or NASA WorldWind. The resolution of these 3D scenes has improved noticeably in the last years, reaching in some urban areas resolutions up to 1m or less for DEM and buildings, and less than 10 cm per pixel in the associated aerial imagery. However, in rural, forest or mountainous areas, the typical resolution for elevation datasets ranges between 5 and 30 meters, and typical resolution of corresponding aerial photographs ranges between 25 cm to 1 m. This current level of detail is only sufficient for aerial points of view, but as the viewpoint approaches the surface the terrain loses its realistic appearance. One approach to augment the detail on top of currently available datasets is adding synthetic details in a plausible manner, i.e. including elements that match the features perceived in the aerial view. By combining the real dataset with the instancing of models on the terrain and other procedural detail techniques, the effective resolution can potentially become arbitrary. There are several applications that do not need an exact reproduction of the real elements but would greatly benefit from plausibly enhanced terrain models: videogames and entertainment applications, visual impact assessment (e.g. how a new ski resort would look), virtual tourism, simulations, etc. In this thesis we propose new methods and tools to help the reconstruction and synthesis of high-resolution terrain scenes from currently available data sources, in order to achieve realistically looking ground-level views. In particular, we decided to focus on rural scenarios, mountains and forest areas. Our main goal is the combination of plausible synthetic elements and procedural detail with publicly available real data to create detailed 3D scenes from existing locations. Our research has focused on the following contributions: - An efficient pipeline for aerial imagery segmentation - Plausible terrain enhancement from high-resolution examples - Super-resolution of DEM by transferring details from the aerial photograph - Synthesis of arbitrary tree picture variations from a reduced set of photographs - Reconstruction of 3D tree models from a single image - A compact and efficient tree representation for real-time rendering of forest landscapesDurant els darrers anys, hem presenciat avenços significatius en el modelat digital de terrenys, principalment gràcies a tècniques fotogramètriques, basades en fotografia aèria o satèl·lit, i a escàners làser. Aquestes tècniques permeten crear Models Digitals d'Elevacions (DEM) i Models Digitals de Superfícies (DSM) que es poden retransmetre per la xarxa i ser explorats mitjançant aplicacions de globus virtuals com ara Google Earth o NASA WorldWind. La resolució d'aquestes escenes 3D ha millorat considerablement durant els darrers anys, arribant a algunes àrees urbanes a resolucions d'un metre o menys per al DEM i edificis, i fins a menys de 10 cm per píxel a les fotografies aèries associades. No obstant, en entorns rurals, boscos i zones muntanyoses, la resolució típica per a dades d'elevació es troba entre 5 i 30 metres, i per a les corresponents fotografies aèries varia entre 25 cm i 1m. Aquest nivell de detall només és suficient per a punts de vista aeris, però a mesura que ens apropem a la superfície el terreny perd tot el realisme. Una manera d'augmentar el detall dels conjunts de dades actuals és afegint a l'escena detalls sintètics de manera plausible, és a dir, incloure elements que encaixin amb les característiques que es perceben a la vista aèria. Així, combinant les dades reals amb instàncies de models sobre el terreny i altres tècniques de detall procedural, la resolució efectiva del model pot arribar a ser arbitrària. Hi ha diverses aplicacions per a les quals no cal una reproducció exacta dels elements reals, però que es beneficiarien de models de terreny augmentats de manera plausible: videojocs i aplicacions d'entreteniment, avaluació de l'impacte visual (per exemple, com es veuria una nova estació d'esquí), turisme virtual, simulacions, etc. En aquesta tesi, proposem nous mètodes i eines per ajudar a la reconstrucció i síntesi de terrenys en alta resolució partint de conjunts de dades disponibles públicament, per tal d'aconseguir vistes a nivell de terra realistes. En particular, hem decidit centrar-nos en escenes rurals, muntanyes i àrees boscoses. El nostre principal objectiu és la combinació d'elements sintètics plausibles i detall procedural amb dades reals disponibles públicament per tal de generar escenes 3D d'ubicacions existents. La nostra recerca s'ha centrat en les següents contribucions: - Un pipeline eficient per a segmentació d'imatges aèries - Millora plausible de models de terreny a partir d'exemples d’alta resolució - Super-resolució de models d'elevacions transferint-hi detalls de la fotografia aèria - Síntesis d'un nombre arbitrari de variacions d’imatges d’arbres a partir d'un conjunt reduït de fotografies - Reconstrucció de models 3D d'arbres a partir d'una única fotografia - Una representació compacta i eficient d'arbres per a navegació en temps real d'escenesPostprint (published version
    corecore