2016
Autores
Santos, DF; Guerreiro, A; Baptista, JM;
Publicação
SIXTH EUROPEAN WORKSHOP ON OPTICAL FIBRE SENSORS
Abstract
This paper presents a numerically investigation of the performance analysis of a conventional photonic crystal fiber (PCF) with a planar metamaterials structure for refractive index sensing, based on surface plasmon resonance (SPR), using the finite element method (FEM). We study the concentration metamaterials conformed by the aluminium oxide (Al2O3) and silver (Ag) and compared its performance with a single metal (Ag), assessing their impacts in the effective refractive index. Furthermore, we also use different types of mechanics to describe the effects of varying the structural parameters sensor on the evanescent field and the sensor performance.
2016
Autores
Migueis, VL; Novoa, H;
Publicação
EXPLORING SERVICES SCIENCE (IESS 2016)
Abstract
A better evaluation and understanding of the client's perception of the service provided by hotels is critical for hotel managers, especially in the "Travel 2.0" era, where tourists not only access but also actively review the service provided. This paper analyses data automatically collected from TripAdvisor reviews regarding 2 star and 5 star hotels in Porto. TripAdvisor user generated content is explored through text mining techniques with the purpose of creating word clouds, synthesizing and prioritizing the aspects of the service raised by customers. Furthermore, this content is analyzed using the SERVQUAL model to identify the service quality dimensions most valued by guests of the two types of hotels. The results of the preliminary study demonstrate that the methodology proposed allows us to identify service perceptions with reasonable effectiveness, highlighting the potential of the procedure to become a complementary tool for hotel management.
2016
Autores
Mascagni de Holanda, JAM; Paiva Cardoso, JMP; Marques, E;
Publicação
PROCEEDINGS OF THE 2016 CONFERENCE ON DESIGN AND ARCHITECTURES FOR SIGNAL & IMAGE PROCESSING
Abstract
This paper describes the mapping and the acceleration of an object detection algorithm on a multiprocessor system based on an FPGA. We use HOG ( Histogram of Oriented Gradients), one of the most popular algorithms for detection of different classes of objects and currently being used in smart embedded systems. The use of HOG on such systems requires efficient implementations in order to provide high performance possibly with low energy/power consumption budgets. Also, as variations and adaptations of this algorithm are needed to deal with different scenarios and classes of objects, programmability is required to allow greater development flexibility. In this paper we show our approach towards implementing the HOG algorithm into a multi-softcore Nios II based-system, bearing in mind high-performance and programmability issues. By applying sourceto-source transformations we obtain speedups of 19x and by using pipelined processing we reduce the algorithms execution time 49x. We also show that improving the hardware with acceleration units can result in speedups of 72.4x compared to the embedded baseline application.
2016
Autores
Fernandes, Sara; Barbosa, LuisSoares;
Publicação
Proceedings of the International Conference on Electronic Governance and Open Society - Challenges in Eurasia, EGOSE 2016, St. Petersburg, Russia, November 22-23, 2016
Abstract
2016
Autores
Conceicao, S; Pendao, C; Moreira, A; Ricardo, M;
Publicação
2016 WIRELESS DAYS (WD)
Abstract
Wireless Underground Networks (WUN) have many applications, such as border surveillance, agriculture monitoring, and infrastructure monitoring. Recent studies have shown that they are feasible and have deployment advantages over wired networks, but only a few WUN evaluations in multiple access scenarios have been done. This paper presents a simulation study on medium access for a WUN with 4 nodes buried, and one node aboveground. The simulations were carried out using the ns-3 simulator and they evaluate both Wi-Fi, and Lr-Wpan networks for dry and wet soils. We verified that for the same number of concurrent nodes, the use of the RTS/CTS mechanism has a much higher influence than the soil water content. Furthermore, a study about the feasibility of using Wi-Fi fingerprinting for positioning above the ground based on the buried infrastructure revealed promising results.
2016
Autores
Alves Rodrigues, I; Ferreira, PG; Moldon, A; Vivancos, AP; Hidalgo, E; Guigo, R; Ayte, J;
Publicação
CELL REPORTS
Abstract
Meiosis is a differentiated program of the cell cycle that is characterized by high levels of recombination followed by two nuclear divisions. In fission yeast, the genetic program during meiosis is regulated at multiple levels, including transcription, mRNA stabilization, and splicing. Mei4 is a forkhead transcription factor that controls the expression of mid-meiotic genes. Here, we describe that Fkh2, another forkhead transcription factor that is essential for mitotic cell-cycle progression, also plays a pivotal role in the control of meiosis. Fkh2 binding preexists in most Mei4-dependent genes, inhibiting their expression. During meiosis, Fkh2 is phosphorylated in a CDK/Cig2-dependent manner, decreasing its affinity for DNA, which creates a window of opportunity for Mei4 binding to its target genes. We propose that Fkh2 serves as a placeholder until the later appearance of Mei4 with a higher affinity for DNA that induces the expression of a subset of meiotic genes.
The access to the final selection minute is only available to applicants.
Please check the confirmation e-mail of your application to obtain the access code.