Alexandre de Almeida Prado Pohl
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View article: Optical collector designs for enhanced performance of visible light communication receivers
Optical collector designs for enhanced performance of visible light communication receivers Open
This work presents the design and analysis of an optical collector for improving the sensitivity of optical receivers used in visible light communication systems (VLC). The collector consists of an aspherical lens integrated with an improv…
View article: Experimental evaluation of MIMO configurations in indoor visible light communications under the consideration of illumination
Experimental evaluation of MIMO configurations in indoor visible light communications under the consideration of illumination Open
Visible light communications (VLC) enable wireless data transmission using existing light-emitting diode (LED) illumination. This experimental study evaluates the performance of multiple input and multiple output (MIMO) configurations in i…
View article: Balancing Illumination and Communication in Indoor VLC: Impact of Multiple LED Configurations on System Performance
Balancing Illumination and Communication in Indoor VLC: Impact of Multiple LED Configurations on System Performance Open
This study explores the influence of multiple luminaire arrangements on the dual functionality of visible light communication systems (VLC), focusing on their impact on illumination uniformity and communication performance. A comprehensive…
View article: 3D printed structures with a tailored refraction index fabricated with an acrylate resin modified by a conjugated polymer
3D printed structures with a tailored refraction index fabricated with an acrylate resin modified by a conjugated polymer Open
Resins for 3D printing usually do not present suitable photoluminescence for application in optoelectronic devices. Herein, a conjugated polymer (PFeBSe) with luminescent and high refraction index properties was synthesized and used to mod…
View article: Assessment of the Illumination and Communication Performance of a Visible Light System in an Indoor Scenario
Assessment of the Illumination and Communication Performance of a Visible Light System in an Indoor Scenario Open
Visible-light communication (VLC) is a technique that employs light-emitting diodes (LEDs) and photodiodes to enable communication in indoor scenarios. VLC has gathered increasing attention due to its potential for data transmission across…
View article: Comment on egusphere-2023-260
Comment on egusphere-2023-260 Open
Abstract. Oceanic Anoxic Event (OAE) 2 (~93.5 millions of years ago) is characterized by widespread marine anoxia and elevated burial rates of organic matter. However, the factors that led to this widespread marine deoxygenation and the po…
View article: Experimental assessment of the performance of cooperative links in visible light communications
Experimental assessment of the performance of cooperative links in visible light communications Open
Cooperative communication is a technique that is employed in the context of visible light communications (VLC) to improve data rate, reach, coverage area and multi-user capacity of installed systems. In this work, we assess the performance…
View article: Theoretical and Experimental Analysis of LED Lamp for Visible Light Communications
Theoretical and Experimental Analysis of LED Lamp for Visible Light Communications Open
Visible light communications (VLC) are an emerging technology that uses light-emitting diodes (LEDs) and photodiodes to provide high-speed communication between devices employing the visible light spectrum. Taking advantage of a large unre…
View article: Stabilising millennial oscillations in large-scale ocean circulation with a delayed feedback due to a circumpolar current
Stabilising millennial oscillations in large-scale ocean circulation with a delayed feedback due to a circumpolar current Open
The global ocean circulation plays a pivotal role in the regulation of the Earth's climate. The specific pattern and strength of circulation also determines how carbon and nutrients are cycled and via the resulting distribution of dissolve…
View article: Performance Assessment of DTN and VANET Protocols for Transmitting Periodic Warning Messages in High Vehicular Density Networks
Performance Assessment of DTN and VANET Protocols for Transmitting Periodic Warning Messages in High Vehicular Density Networks Open
In recent years, routing protocols for Delay Tolerant Networks (DTN) have become appealing for vehicular ad-hoc networks (VANET), particularly for communication between vehicles in highly sparse environments. In such scenarios, network dis…
View article: Comment on bg-2021-118
Comment on bg-2021-118 Open
Abstract. We investigate the ways in which marine biologically mediated heating increases the surface atmospheric temperature. While the effects of phytoplankton light absorption on the ocean have gained attention over the past years, the …
View article: Use of a differential evolution algorithm for determining input driving signals in optical frequency combs
Use of a differential evolution algorithm for determining input driving signals in optical frequency combs Open
In this work, a genetic algorithm based on differential evolution is proposed to identify sets of input driving signals used in the generation of optical frequency combs with Mach-Zehnder intensity modulators. Simulation results show that …
View article: Multi-wavelength reflection spectra from an acousto-optic modulated fiber Bragg grating in a highly birefringent suspended core fiber
Multi-wavelength reflection spectra from an acousto-optic modulated fiber Bragg grating in a highly birefringent suspended core fiber Open
The interaction of a fiber Bragg grating and longitudinal acoustic waves in a highly birefringent suspended-core fiber is investigated for the realization of a multi-wavelength reflection property. The modulated grating couples power from …
View article: Electrically Tunable Multiwavelength Bragg Grating Filter Acoustically Induced in a Highly Birefringent Suspended Core Fiber
Electrically Tunable Multiwavelength Bragg Grating Filter Acoustically Induced in a Highly Birefringent Suspended Core Fiber Open
Multiwavelength reflection spectra induced by an acoustically modulated fiber Bragg grating (FBG) in a highly birefringent suspended core fiber are experimentally investigated. Longitudinal acoustic waves interacting with a grating generat…
View article: All-fiber laser mode-locked by the acousto-optic modulation of a fiber Bragg grating in suspended core fiber
All-fiber laser mode-locked by the acousto-optic modulation of a fiber Bragg grating in suspended core fiber Open
An ytterbium-doped fiber laser mode-locked by the interaction of a fiber Bragg grating and longitudinal acoustic waves in a suspended core fiber is experimentally investigated. An optimized design of an acousto-optic modulator is also prop…
View article: All-fiber 10 MHz acousto-optic modulator of a fiber Bragg grating at 1060 nm wavelength
All-fiber 10 MHz acousto-optic modulator of a fiber Bragg grating at 1060 nm wavelength Open
Acousto-optic modulation of a 1 cm fiber Bragg grating at 10.9 MHz frequency and 1065 nm wavelength is demonstrated for the first time. A special modulator design is employed to acoustically induce a dynamic radial long period grating whic…
View article: Strain and temperature characterization of LPGs written by CO2 laser in pure silica LMA photonic crystal fibers
Strain and temperature characterization of LPGs written by CO2 laser in pure silica LMA photonic crystal fibers Open
This paper reports on the writing of long period gratings (LPGs) in a six-ring pure silica solid core, and large mode area photonic crystal fiber (fiber core diameter ρ = 10.1 μm) using a CO2 laser system, and the characterization of their…
View article: Long Period Bragg Grating in Coaxial Transmission Lines
Long Period Bragg Grating in Coaxial Transmission Lines Open
This work shows the utilization of a coaxial cable for the fabrication of a long period Bragg grating. The grating is fabricated removing the dielectric in short pieces of the cable so that the discontinuities account for the variation in …
View article: Transmission and Reception Tests of Digital Terrestrial TV in the Metropolitan Region of Curitiba
Transmission and Reception Tests of Digital Terrestrial TV in the Metropolitan Region of Curitiba Open
This paper describes the preliminary test results of the transmission and reception of Digital TV signals, on Channel 41, in the metropolitan region of Curitiba, in the state of Paraná, Brazil.It describes the equipment configuration deplo…
View article: Foveated Model based on the Action Potential of Ganglion Cells to Improve Objective Image Quality Metrics
Foveated Model based on the Action Potential of Ganglion Cells to Improve Objective Image Quality Metrics Open
In this work, a foveated model (FM) based on the action potential of ganglion cells in the human retina is employed to improve the results obtained by traditional and perceptual image quality metrics. LIVE and VAIQ image databases are used…
View article: Experimental Investigation of Digital TV Signals with Multipath in Curitiba
Experimental Investigation of Digital TV Signals with Multipath in Curitiba Open
This article describes experimental propagation measurements of DTV signals in the urban region of Curitiba.A digital TV analyzer manufactured by Rohde & Schwarz, model ETL was used [1], which is able to differentiate open TV channel signa…
View article: Digital TV Signal Reception Testing in a Device with Spatial Diversity
Digital TV Signal Reception Testing in a Device with Spatial Diversity Open
This paper presents the test results performed in internal and external environments employing tuner demodulator hardware with spatial diversity.Two types of antennae were used: monopole and hemispherical helical.The results demonstrated t…
View article: Objective No-Reference Video Quality Assessment Method Based on Spatio-Temporal Pixel Analysis
Objective No-Reference Video Quality Assessment Method Based on Spatio-Temporal Pixel Analysis Open
Digital video signals are subject to several distortions due to compression processes, transmission over noisy channels or video processing. Therefore, the video quality evaluation has become a necessity for broadcasters and content provid…