2016
Autores
Dias, J; Sousa, F; Ribeiro, F; Campos, R; Ricardo, M;
Publicação
2016 12TH ANNUAL CONFERENCE ON WIRELESS ON-DEMAND NETWORK SYSTEMS AND SERVICES (WONS)
Abstract
The rise of the Internet of Things and the growth of the IP cameras market are making Wireless Video Sensor Networks (WVSNs) popular. In turn, Wi-Fi is becoming the enabling technology for WVSNs due to its flexibility, high bitrates provided and low cost; however, these networks suffer from three major problems: bad performance, throughput unfairness, and energy inefficiency. In order to address the lack of holistic solutions to solve these problems, we propose the FM-WiFIX+ solution. This solution uses FM radio as an out-of-band control channel to signal when a video sensor should turn its IEEE 802.11 interface OFF, thus saving energy. The results obtained with a proof-of-concept prototype show that for a network with 7 nodes the proposed solution can achieve gains of energy up to 48 %, while maintaining good levels of performance and throughput fairness.
2016
Autores
Bessa, J; Barreira, J; Faria, N; Martins, J; Barbosa, L; Bessa, M;
Publicação
2016 11TH IBERIAN CONFERENCE ON INFORMATION SYSTEMS AND TECHNOLOGIES (CISTI)
Abstract
In the last three decades with the Information Technologies advent and the growth of the concept of Virtual Environments, a set of new ways to perform tasks have emerged, in the most diversified areas of society. The main focus of this work was to verify if it was possible to increase the sense of presence through multi-sensory stimulation, creating a virtual environment of simulation that causes stress in exposure therapy, in this case in people who have a fear of heights. The evaluation of the sense of presence was made using the Portuguese version of a previously validated IPQ (Igroup Presence Questionnaire) and also through direct observation of the movements caused by oculomotor reflexes. Although the achievement results that were not very significant between the two tested groups, the multisensory simulation environment obtained better results in terms of involvement in relation to space and realism, which increased concentration in the experience. The obtained results seem to indicate that the alone addition of further stimuli does not lead to an increased feeling of presence, therefore existing the need to understand which are the critical stimuli for each assessment situation.
2016
Autores
Baquero, C; Preguiça, NM;
Publicação
ACM Queue
Abstract
Any computing system can be described as executing sequences of actions, with an action being any relevant change in the state of the system. For example, reading a file to memory, modifying the contents of the file in memory, or writing the new contents to the file are relevant actions for a text editor. In a distributed system, actions execute in multiple locations; in this context, actions are often called events. Examples of events in distributed systems include sending or receiving messages, or changing some state in a node. Not all events are related, but some events can cause and influence how other, later events occur. For example, a reply to a received mail message is influenced by that message, and maybe by prior messages received.
2016
Autores
Ono, YH; Correia, CM; Lardière, O; Andersen, DR; Oya, S; Akiyama, M; Gamroth, D; Jackson, K; Martin, O; Bradley, C;
Publicação
ADAPTIVE OPTICS SYSTEMS V
Abstract
This paper presents the AO performance we got on-sky with RAVEN, a Multi-Object Adaptive Optics (MOAO) technical and science demonstrator installed and tested at the Subaru telescope. We report Ensquared-Energy (EE) and Full Width at Half Maximum (FWHM) measured from science images on Subaru's IRCS taken during all of the on-sky observing runs. We show these metrics as function of different AO modes and atmospheric conditions for two asterisms of natural guide stars. The performances of the MOAO and Ground-Layer AO (GLAO) modes are between the classical Single-Conjugate AO (SCAO) and seeing-limited modes. We achieve the EE of 30% in H-band with the MOAO correction, which is a science requirement for RAVEN. The MOAO provides sightly better performance than the GLAO mode in both asterisms. One of the reasons which cause this small difference between the MOAO and GLAO modes may be the strong GL contribution. Also, the performance of the MOAO modes is affected by the accuracy of the on-sky turbulence profiling by the SLOpe Detection And Ranging (SLODAR) method.
2016
Autores
Oliveira, A; Perdigao, C; Santos, LP; Proenca, A;
Publicação
2016 23RD PORTUGUESE MEETING ON COMPUTER GRAPHICS AND INTERACTION (EPCGI)
Abstract
The CG research community has a renewed interest on rendering algorithms based on path space integration, mainly due to new approaches to discover, generate and exploit relevant light paths while keeping the numerical integrator unbiased or, at the very least, consistent. Simultaneously, the current trend towards massive parallelism and heterogeneous environments, based on a mix of conventional computing units with accelerators, is playing a major role both in HPC and embedded platforms. To efficiently use the available resources in these and future systems, algorithms and software packages are being revisited and reevaluated to assess their adequateness to these environments. This paper assesses the performance and scalability of three different path based algorithms running on homogeneous servers (dual multicore Xeons) and heterogeneous systems (those multicore plus manycore Xeon and NVidia Kepler GPU devices). These algorithms include path tracing (PT), its bidirectional counterpart (BPT) and the more recent Vertex Connect and Merge (VCM). Experimental results with two conventional scenes (one mainly diffuse, the other exhibiting specular-diffuse-specular paths) show that all algorithms scale well across the different platforms, the actual scalability depending on whether shared data structures are accessed or not (PT vs. BPT vs. VCM).
2016
Autores
Ferreira, PG; Oti, M; Barann, M; Wieland, T; Ezquina, S; Friedländer, MR; Rivas, MA; Esteve-Codina, A; Estivill, X; Guigó, R; Dermitzakis, E; Antonarakis, S; Meitinger, T; Strom, TM; Palotie, A; François Deleuze, J; Sudbrak, R; Lerach, H; Gut, I; Syvänen, A; Gyllensten, U; Schreiber, S; Rosenstiel, P; Brunner, H; Veltman, J; Hoen, PA; Jan van Ommen, G; Carracedo, A; Brazma, A; Flicek, P; Cambon-Thomsen, A; Mangion, J; Bentley, D; Hamosh, A; Rosenstiel, P; Strom, TM; Lappalainen, T; Guigó, R; Sammeth, M;
Publicação
SCIENTIFIC REPORTS
Abstract
Recent advances in the cost-efficiency of sequencing technologies enabled the combined DNA-and RNA-sequencing of human individuals at the population-scale, making genome-wide investigations of the inter-individual genetic impact on gene expression viable. Employing mRNA-sequencing data from the Geuvadis Project and genome sequencing data from the 1000 Genomes Project we show that the computational analysis of DNA sequences around splice sites and poly-A signals is able to explain several observations in the phenotype data. In contrast to widespread assessments of statistically significant associations between DNA polymorphisms and quantitative traits, we developed a computational tool to pinpoint the molecular mechanisms by which genetic markers drive variation in RNA-processing, cataloguing and classifying alleles that change the affinity of core RNA elements to their recognizing factors. The in silico models we employ further suggest RNA editing can moonlight as a splicing-modulator, albeit less frequently than genomic sequence diversity. Beyond existing annotations, we demonstrate that the ultra-high resolution of RNA-Seq combined from 462 individuals also provides evidence for thousands of bona fide novel elements of RNA processing-alternative splice sites, introns, and cleavage sites-which are often rare and lowly expressed but in other characteristics similar to their annotated counterparts.
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