Laser scanning technique from airborne and land platforms has been largely used for collecting 3D data in large volumes in the field of geosciences. Furthermore, the laser pulse intensity has been widely exploited to analyze and classify rocks and biomass, and for carbon storage estimation. In general, a laser beam is emitted, collides with targets [...]
This paper presents a comparative study about 3D reconstruction based on active and passive sensors, mainly LiDAR – Terrestrial Laser Scanner (TLS) and raster images (photography), respectively. An accuracy analysis has been performed in the positioning of outcrop point clouds obtained by both techniques. To make the comparison feasible, datasets are composed by point clouds [...]
Authentication and authorization are two of the most important services for any IT infrastructure. Taking into account the current state of affairs of cyber warfare, the security and dependability of such services is a first class priority. For instance, the correct and continuous operation of identity providers (e.g., OpenID) and authentication, authorization and accounting services [...]
Elasticity is undoubtedly one of the most striking characteristics of cloud computing. Especially in the area of high performance computing (HPC), elasticity can be used to execute irregular and CPU-intensive applications. However, the on- the-fly increase/decrease in resources is more widespread in Web systems, which have their own IaaS-level load balancer. Considering the HPC area, [...]
Researchers, in Multimodal Interaction Systems, devote substantial effort to the integration of external stimulus and signal, to the internal representation of this information and to the response generation. Nevertheless, they focus less effort on how to integrate studies in Cognitive Psychology regarding the human interaction subject. Therefore, it becomes interesting to evaluate the assumption that [...]
Process rescheduling is a known technique to face with system heterogeneity and dynamism, being especially pertinent on Bulk Synchronous Parallel (BSP) programs. These programs are organized in a set of round-based supersteps, in which the slowest process determines the moment of synchronization. This approach motivated us to develop a first model called MigBSP, which combines [...]
Elasticity is one of the most known capabilities related to cloud computing, being largely deployed reactively using thresholds. In this way, maximum and minimum limits are used to drive resource allocation and deallocation actions, leading to the following problem statements: How can cloud users set the threshold values to enable elasticity in their cloud applications? [...]
This paper presents a parallel modeling of a lossy image compression method based on the fractal theory and its evaluation over two versions of dual-core processors: with and without simultaneous multithreading (SMT) support. The idea is to observe the speedup on both configurations when changing application parameters and the number of threads at operating system [...]
Descrição: A qualidade de serviços e a experiência dos usuários é de extrema importância para a melhoria de redes sem fio. Por exemplo, serviços oferecidos pela rede sem fio EDUROAM, gerenciada pela Rede Nacional de Ensino e Pesquisa (RNP), poderiam ser aperfeiçoados através da coleta de informações dos dispositivos e usuários. Entretanto, soluções em prol [...]
Professionals are constantly seeking qualification and consequently increasing their knowledge in their area of expertise. Thus, it is interesting to develop a computer system that knows its users and their work history. Using this information, even in the case of professional role change, the system could allow the renewed authorization for activities, based on previously [...]