Time-varying volume visualization

Volume rendering is a very active research field in Computer Graphics because of its wide range of applications in various sciences, from medicine to flow mechanics. In this report, we survey a state-of-the-art on time-varying volume rendering. We state several basic concepts and then we establish several criteria to classify the studied works: IVR versus DVR, 4D versus 3D+time, compression techniques, involved architectures, use of parallelism and image-space versus object-space coherence. We also address other related problems as transfer functions and 2D cross-sections computation of time-varying volume data. All the papers reviewed are classified into several tables based on the mentioned classification and, finally, several conclusions are presented.Preprin

The evolution of the ventilatory ratio is a prognostic factor in mechanically ventilated COVID-19 ARDS patients

Background: Mortality due to COVID-19 is high, especially in patients requiring mechanical ventilation. The purpose of the study is to investigate associations between mortality and variables measured during the first three days of mechanical ventilation in patients with COVID-19 intubated at ICU admission. Methods: Multicenter, observational, cohort study includes consecutive patients with COVID-19 admitted to 44 Spanish ICUs between February 25 and July 31, 2020, who required intubation at ICU admission and mechanical ventilation for more than three days. We collected demographic and clinical data prior to admission; information about clinical evolution at days 1 and 3 of mechanical ventilation; and outcomes. Results: Of the 2,095 patients with COVID-19 admitted to the ICU, 1,118 (53.3%) were intubated at day 1 and remained under mechanical ventilation at day three. From days 1 to 3, PaO2/FiO2 increased from 115.6 [80.0-171.2] to 180.0 [135.4-227.9] mmHg and the ventilatory ratio from 1.73 [1.33-2.25] to 1.96 [1.61-2.40]. In-hospital mortality was 38.7%. A higher increase between ICU admission and day 3 in the ventilatory ratio (OR 1.04 [CI 1.01-1.07], p = 0.030) and creatinine levels (OR 1.05 [CI 1.01-1.09], p = 0.005) and a lower increase in platelet counts (OR 0.96 [CI 0.93-1.00], p = 0.037) were independently associated with a higher risk of death. No association between mortality and the PaO2/FiO2 variation was observed (OR 0.99 [CI 0.95 to 1.02], p = 0.47). Conclusions: Higher ventilatory ratio and its increase at day 3 is associated with mortality in patients with COVID-19 receiving mechanical ventilation at ICU admission. No association was found in the PaO2/FiO2 variation

Conceptes avançats en desenvolupament de programari lliure, febrer 2007

En aquesta assignatura es presenten tecnologies avançades per al desenvolupament d'aplicacions mitjançant l'ús de programari lliure. Inclouen eines per a facilitar la programació, interfícies gràfiques d'usuari i alguns elements gràfics existents, entre d'altres. També s'hi inclouen alguns conceptes importants i metodologies per a ajudar en l'esmentada tasca de programació.En esta asignatura se presentan tecnologías avanzadas para el desarrollo de aplicaciones mediante el uso de software libre. Estas incluyen herramientas para facilitar la programación, interfaces gráficas de usuario, así como algunos elementos gráficos existentes, entre otros. Se incluyen también algunos conceptos importantes y metodologías para ayudar en dicha tarea de programación.In this course advanced technologies for the development of applications through the use of free software are presented. These include tools to facilitate programming, graphical user interfaces, as well as some existing graphical elements, among others. Some important concepts and methodologies are also included to help in this task of programming

Conceptos avanzados en desarrollo de software libre, febrero 2007

En aquesta assignatura es presenten tecnologies avançades per al desenvolupament d'aplicacions mitjançant l'ús de programari lliure. Inclouen eines per a facilitar la programació, interfícies gràfiques d'usuari i alguns elements gràfics existents, entre d'altres. També s'hi inclouen alguns conceptes importants i metodologies per a ajudar en l¿esmentada tasca de programació.En esta asignatura se presentan tecnologías avanzadas para el desarrollo de aplicaciones mediante el uso de software libre. Estas incluyen herramientas para facilitar la programación, interfaces gráficas de usuario, así como algunos elementos gráficos existentes, entre otros. Se incluyen también algunos conceptos importantes y metodologías para ayudar en dicha tarea de programación.In this course advanced technologies for the development of applications through the use of free software are presented. These include tools to facilitate programming, graphical user interfaces, as well as some existing graphical elements, among others. Some important concepts and methodologies are also included to help in this task of programming

Conceptos avanzados en desarrollo de software libre, febrero 2007

En aquesta assignatura es presenten tecnologies avançades per al desenvolupament d'aplicacions mitjançant l'ús de programari lliure. Inclouen eines per a facilitar la programació, interfícies gràfiques d'usuari i alguns elements gràfics existents, entre d'altres. També s'hi inclouen alguns conceptes importants i metodologies per a ajudar en l¿esmentada tasca de programació.En esta asignatura se presentan tecnologías avanzadas para el desarrollo de aplicaciones mediante el uso de software libre. Estas incluyen herramientas para facilitar la programación, interfaces gráficas de usuario, así como algunos elementos gráficos existentes, entre otros. Se incluyen también algunos conceptos importantes y metodologías para ayudar en dicha tarea de programación.In this course advanced technologies for the development of applications through the use of free software are presented. These include tools to facilitate programming, graphical user interfaces, as well as some existing graphical elements, among others. Some important concepts and methodologies are also included to help in this task of programming

Conceptos avanzados en desarrollo de software libre, febrero 2007

En aquesta assignatura es presenten tecnologies avançades per al desenvolupament d'aplicacions mitjançant l'ús de programari lliure. Inclouen eines per a facilitar la programació, interfícies gràfiques d'usuari i alguns elements gràfics existents, entre d'altres. També s'hi inclouen alguns conceptes importants i metodologies per a ajudar en l¿esmentada tasca de programació.En esta asignatura se presentan tecnologías avanzadas para el desarrollo de aplicaciones mediante el uso de software libre. Estas incluyen herramientas para facilitar la programación, interfaces gráficas de usuario, así como algunos elementos gráficos existentes, entre otros. Se incluyen también algunos conceptos importantes y metodologías para ayudar en dicha tarea de programación.In this course advanced technologies for the development of applications through the use of free software are presented. These include tools to facilitate programming, graphical user interfaces, as well as some existing graphical elements, among others. Some important concepts and methodologies are also included to help in this task of programming

Conceptes avançats en desenvolupament de programari lliure, febrer 2007

En aquesta assignatura es presenten tecnologies avançades per al desenvolupament d'aplicacions mitjançant l'ús de programari lliure. Inclouen eines per a facilitar la programació, interfícies gràfiques d'usuari i alguns elements gràfics existents, entre d'altres. També s'hi inclouen alguns conceptes importants i metodologies per a ajudar en l'esmentada tasca de programació.En esta asignatura se presentan tecnologías avanzadas para el desarrollo de aplicaciones mediante el uso de software libre. Estas incluyen herramientas para facilitar la programación, interfaces gráficas de usuario, así como algunos elementos gráficos existentes, entre otros. Se incluyen también algunos conceptos importantes y metodologías para ayudar en dicha tarea de programación.In this course advanced technologies for the development of applications through the use of free software are presented. These include tools to facilitate programming, graphical user interfaces, as well as some existing graphical elements, among others. Some important concepts and methodologies are also included to help in this task of programming

System for Automated Assistance in Correction of Programming Exercises (SAC)

In university programming classes often hundreds of students participate having to solveeach hundreds of programming assignments a situation which puts instructors to the difficult task of validating hundreds of programming assignments. We present a framework thatcan help instructors and students in organization and validation of program code. Our “System for Automated Assistance in Correction of Programming Exercises“ (short: SAC) is aweb-platform for test-driven development and automated validation. The web-platform isbased on Java Server Pages technology with tomcat as servlet container, and allows teachersto specify and define program exercises and students to upload their solutions. Students can get immediate feedback on the validity of their code and both instructors and students cansee statistics about each programming assignment. We explain our platform and proposehow the automatic validation can be extended. QC 2012020

Organisational adaptation of multi-agent systems in a peer-to-peer scenario

Organisations in Multi-Agent Systems (MAS) have proven to be successful in regulating agent societies. Nevertheless, changes in agents' behaviour or in the dynamics of the environment may lead to a poor fulfilment of the system's purposes, and so the entire organisation needs to be adapted. In this paper we focus on endowing the organisation with adaptation capabilities, instead of expecting agents to be capable of adapting the organisation by themselves. We regard this organisational adaptation as an assisting service provided by what we call the Assistance Layer. Our generic Two Level Assisted MAS Architecture (2-LAMA) incorporates such a layer. We empirically evaluate this approach by means of an agent-based simulator we have developed for the P2P sharing network domain. This simulator implements 2-LAMA architecture and supports the comparison between different adaptation methods, as well as, with the standard BitTorrent protocol. In particular, we present two alternatives to perform norm adaptation and one method to adapt agents'relationships. The results show improved performance and demonstrate that the cost of introducing an additional layer in charge of the system's adaptation is lower than its benefits