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2D nanomaterials saturable absorbers fabrication using the droplet method for Erbium-doped fiber lasers
Gerosa R.M.; Steinberg D.; Marcondes R.L.; Domingues S.H.; Saito L.A.M. (2016)
© 2016 Optical Society of America.We present the simple and powerful droplet method to fabricate liquid exfoliated graphene oxide, reduced graphene oxide and black phosphorus polymer-based samples as all-fiber saturable absorbers for ultrashort pulse generation in Erbium-doped fiber lasers.
2D nanomaterials saturable absorbers fabrication using the droplet method for erbium-doped fiber lasers
Gerosa R.M.; Steinberg D.; Marcondes R.L.; Domingues S.H.; Saito L.A.M. (2016)
© 2016 OSA.We present the simple and powerful droplet method to fabricate liquid exfoliated graphene oxide, reduced graphene oxide and black phosphorus polymer-based samples as all-fiber saturable absorbers for ultrashort pulse generation in Erbium-doped fiber lasers.
3-D solar atmospheric model over active regions
Seihorst C.L.; Costa J.E.R.; Silva A.V.R. (2005)
We present here the first results of our 3-D solar atmospheric model over active regions based on radio observations. Intense magnetic fields take place in active regions, which may result in a gyro-resonance emission contribution to the brightness temperature observed at radio frequencies. This model considers the temperature and densities (electrons and ions) distributions, as well as the local magnetic 3-D structure. The location of the magnetic field lines was obtained from force-free extrapolation of MDI (SOHO) magnetograms. This procedure yields three cubes with magnetic field intensities, one for each vector component. Magnetic loops are simulated by filling the region around each magnetic field line with densities and temperature values distinct from the quiet solar atmosphere. Thus, the atmospheric region changes where these flux tubes are present. The model, represented by a volume of 500×500×200 arcsec3, has as free parameters: the flux tube distributions of temperature and density, as well the width. For each column of the cube representing the atmosphere, the equations of radiative transport (including bremsstrahlung and gyro-resonance emission) were solved for the brightness temperature at 17 GHz. These brightness temperature of 500×500 arcsec2 were compared with high spatial resolution solar maps at 17 GHz observed by the Nobeyama Radioheliograph (NoRH). The free parameters are varied so as to obtain the best match to the observations. As a result, the observations are repoduced by an active region model with maximum brightness temperature of 5.2×104 K, magnetic flux tubes with 10 times the local density and 4 times the local temperature below the transition region, and above it, 6 and 2 times the local densities and temperatures, respectively. For this same region, the gyro-resonance emission is negligible compared to the bremsstrahlung contribution, even though the photospheric magnetic field intensities reach 1800 G. The magnetic field contributed mainly for the geometry of the problem.
300-fs mode-locked Erbium doped fiber laser using evanescent field interaction through graphene oxide saturable absorber in D-shaped fibers
Gerosa R.M.; Steinberg D.; Pellicer F.N.; Domingues S.H.; de Souza E.A.T.; Saito L.A.M. (2016)
© OSA 2016.We report the ultrashort pulse generation of 310 fs from a mode-locked Erbium doped fiber laser using a spin-coated graphene oxide saturable absorber film deposited onto a sidepolished D-shaped optical fiber.
396 fs, 2.5-12 GHz asynchronous mode-locking erbium fiber laser
Boncristiano E.S.; Saito L.A.M.; De Souza E.A. (2007)
396 fs pulses with adjustable repetition rate from 2.5 GHz to 12 GHz were directly generated by an asynchronous modelocked Er-fiber laser in conjunction with intracavity solitonic effect in a hybrid regime. © 2007 Optical Society of America.
396 fs, 2.5-12 GHz asynchronous mode-locking erbium fiber laser
Boncristiano E.S.; Saito L.A.M.; De Souza E.A. (2007)
396 fs pulses with adjustable repetition rate from 2.5 GHz to 12 GHz were directly generated by an asynchronous modelocked Er-fiber laser in conjunction with intracavity solitonic effect in a hybrid regime. © 2007 Optical Society of America.
3D interactive environment applied to fencing training
Guimaraes C.P.; Balbio V.; Cid G.L.; Orselli M.I.V.; Xavier A.P.; Neto A.S.; Correa S.C. (2016)
© Copyright 2016 by SCITEPRESS - Science and Technology Publications, Lda. All rights reserved.The purpose of this study was to present a 3D interactive environment - a Digital Platform to help in fencing training. The first fencing motion described and analysed at the 3D platform was lunge in epee fencing. The platform was able to show kinematic variables of upper and lower limbs and the center of mass that characterized a good performance in epee fencing. The platform also incorporates a digital database of eye track motions of the fencers. An OptiTrack motion capture system was used to capture the lunge motion of five skilled amateur fencing athletes in the presence or not of a static opponent and an Eye Track System Tobbi II was used to track the eye movements of the fencers when performing a lunge attack with a target. The 3D platform was developed using Unity3D and can present some interesting results to improve available information to coaches. That highlights the importance of visualization biomechanical results based on coach criteria in a more understandable way to help athletic training.
40 Gb/s RZ DQPSK transmission with SPM and ASE suppression by dispersion management
Susskind S.; De Souza E.A. (2009)
We demonstrate a 40 Gb/s RZ DQPSK single channel transmission over 2900 km of SMF, using a 40 GHz bandwidth optical receiver filter to suppress ASE and improve OSNR. The interaction of SPM and accumulated dispersion is evaluated by minutely system dispersion management. Additionally, we successfully employ a 10 channel DWDM ranging from 1560.20 nm to 1563.86 nm at 40 Gb/s RZ DQPSK and 50 GHz of channel spacing over 1000 km, without raman amplification or special polarization multiplex. ©2009IEEE.
50 km ultralong erbium fiber laser with soliton pulse compression
Saito L.A.M.; De Souza E.A. (2010)
We demonstrated a 50 km ultralong Erbium fiber laser actively mode locked with repetition rate varying from 1 to 10 GHz. The output pulse widths were determined by soliton regime at 1 and 2.5 GHz. © 2010 Optical Society of America.
50 km ultralong erbium fiber laser with soliton pulse compression
Saito L.A.M.; De Souza E.A. (2010)
We demonstrated a 50 km ultralong Erbium fiber laser actively mode locked with repetition rate varying from 1 to 10 GHz. The output pulse widths were determined by soliton regime at 1 and 2.5 GHz. © 2010 Optical Society of America.
58 kHz ultra-low repetition rate ultralong Erbium-doped fiber laser mode-locked by carbon nanotubes
Rosa H.G.; De Souza E.A. (2011)
In this paper we present a 58 kHz fundamental repetition rate 3.5 km long EDFL mode-locked by SWCNT saturable absorbers. Because laser nonlinearities and accumulated dispersion, we observed chirped soliton-like 6.79 ps pulses with 0.49 nm spectral width. This is the lowest repetition rate in EDFL, to the best of our knowledge. © 2011 OSA.
58 kHz ultra-Low repetition rate ultralong erbium-doped fiber laser mode-Locked by carbon nanotubes
Rosa H.G.; De Souza E.A. (2011)
In this paper we present a 58 kHz fundamental repetition rate 3.5 km long EDFL mode-locked by SWCNT saturable absorbers. Because laser nonlinearities and accumulated dispersion, we observed chirped soliton-like 6.79 ps pulses with 0.49 nm spectral width. This is the lowest repetition rate in EDFL, to the best of our knowledge. ©2010 Optical Society of America.
58 kHz ultra-low repetition rate ultralong erbium-doped fiber laser mode-locked by carbon nanotubes
Rosa H.G.; de Souza E.A. (2011)
In this paper we present a 58 kHz fundamental repetition rate 3.5 km long EDFL mode-locked by SWCNT saturable absorbers. Because laser nonlinearities and accumulated dispersion, we observed chirped soliton-like 6.79 ps pulses with 0.49 nm spectral width. This is the lowest repetition rate in EDFL, to the best of our knowledge. ©2010 Optical Society of America.
58 kHz ultra-low repetition rate ultralong erbium-doped fiber laser mode-locked by carbon nanotubes
Rosa H.G.; de Souza E.A. (2011)
In this paper we present a 58 kHz fundamental repetition rate 3.5 km long EDFL mode-locked by SWCNT saturable absorbers. Because laser nonlinearities and accumulated dispersion, we observed chirped soliton-like 6.79 ps pulses with 0.49 nm spectral width. This is the lowest repetition rate in EDFL, to the best of our knowledge. © 2010 Optical Society of America.
A bacterial colony algorithm for association rule mining
da Cunha D.S.; Xavier R.S.; de Castro L.N. (2015)
© Springer International Publishing Switzerland 2015.Bacterial colonies perform a cooperative distributed exploration of the environment. This paper describes bacterial colony networks and their skills to explore resources as a tool for mining association rules in databases. The proposed algorithm is designed to maintain diverse solutions to the problem at hand, and its performance is compared to other well-known bio-inspired algorithms, including a genetic and an immune algorithm (CLONALG) and, also, to Apriori over some benchmarks from the literature.
A bee-inspired algorithm for optimal data clustering
Cruz D.P.F.; Maia R.D.; Szabo A.; De Castro L.N. (2013)
The amount of data generated in different knowledge areas has made it necessary the use of data mining tools capable of automatically analyzing and extracting knowledge from datasets. Clustering is one of the most important tasks in data mining and can be defined as the process of partitioning objects into groups or clusters, such that objects in the same group are more similar to one another than to objects belonging to other groups. In this context, this paper aims to propose an adaptation of a bee-inspired optimization algorithm so that it is able to solve data clustering problems. The algorithm was run for different datasets and the results obtained showed high quality clusters and diversity of solutions, whilst a suitable number of clusters was automatically determined. © 2013 IEEE.
A bee-inspired data clustering approach to design RBF neural network classifiers
Cruz D.P.F.; da Silva L.A.; de Castro L.N.; Maia R.D. (2014)
Different methods have been used to train radial basis function neural networks. This paper proposes a bee-inspired algorithm to automatically select the number and location of basis functions to be used in such RBF network. The algorithm was designed to solve data clustering problems, where the centroids of clusters are used as centers for the RBF network. The approach presented in this paper is preliminary evaluated in three synthetic datasets, two classification datasets and one function approximation problem, and its results suggest a potential for real-world application. © Springer International Publishing Switzerland 2014.
A bee-inspired multiobjective optimization clustering algorithm
Cruz D.; Politi A.; Cunha D.; De Castro L.N.; Maia R.D. (2016)
Multiobjective clustering techniques have been used to simul-taneously consider several complementary aspects of cluster-ing quality. They optimize more than one cluster validity index simultaneously, leading to high-quality results, and have emerged as attractive and robust alternatives for clustering problems. This paper proposes a bee-inspired multiobjective optimization algorithm to solve data clustering problems. The algorithm was run for different datasets and the results ob-tained showed high quality clusters and diversity of solutions, whilst a suitable number of clusters was automatically deter-mined.
A case study of gamification and PBL integration as an active learning pathway
Saut A.M.; Vieira M.; Maestrelli N.C.; Vicente S. (2023)
© 2023 University of Minho. All rights reserved.This paper presents a case study of gamification and PBL (Problem-Based Learning) integration as toolbox to enhance active learning and to promote problem-solving skills. Gamification can be defined as using game design techniques, game thinking, and game mechanics to improve non-game contexts, with the aim of increasing user interactivity. PBL is one of the learning techniques that use problems as a context for students to get into practice about critical thinking and to obtain knowledge from subject matter problems. An experience was carried out using Quality Tools gamification that was developed for undergraduate students of Mechanical Engineering. These experiences were developed using the teaching role in PBL to set problems, ask questions, and to facilitate students' comprehension. The integrated use of gamification and PBL might turn students into more independent learners, allowing selected learning strategies, and to become able to control the learning process and exploring their creativity. Some results based on student's perspective are showed in this paper. The results shown a comparison between different scenarios for traditional learning methods application and active learning, and the conclusions indicated the benefits of active learning comparing with traditional learning methods. However, it is possible to understand the importance of technology advancement and its significant influence on gamification and PBL integration. It's possible to conclude that the investigated strategy makes problem-based learning process more efficient. The results of this case study have shown that the use of several technologies supported by gamification can increase the chance of improving the learning process.
A case study of search-based path planning for a semi-autonomous mobile robot using visibility algorithms
Marinheiro R.M.; Bianchini C.P. (2020)
© 2020 IEEE.Machines' capability to reproduce human abilities is the new source of technological advances. One of the most discussed approaches is the autonomous vehicles, machines that can move from place to place without human intervention in a safer way, since they can predict accidents. This research's goal is to bring forward algorithms to a semiautonomous mobile robot that has the purpose of searching an object in a known environment. To this end, algorithms that fit the case were selected and implemented. Such elected algorithms proved being able to construct the robot's intelligence efficiently.

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