A multiobjective optimization on the parameters of direct-detection optical orthogonal frequency division multiplexing (DDO-OFDM) systems in short-range links is proposed. Based on genetic algorithms, the optimization process takes into account the influence of optical power in the guard-band reduction of such multicarrier systems with 4and 16-quadratic-amplitude modulation (QAM) subcarrier mapping and for propagation in 40 km of standard single-mode fiber (SSMF). Simulation results show that the parameters optimization is responsible for a gain of approximately 2.5 dB [≈ 1.8 dB] in the required optical power for bit-errorrate ≤10 ^-3 , for DDO-OFDM system transmission over 40 km of uncompensated SSMF, with a guard band B _G equals to 50% of the signal bandwidth B _w and 16-QAM [4-QAM] subcarrier mapping. For an extremely reduced guard band of only 1% of B _w , the gain reduced to ≈ 0.5 dB and ≈ 1.5 dB for 16and 4-QAM mapping, respectively. The optimization process is experimentally validated under the transmission of the optimized DDO-OFDM systems in optical back-to-back (B2B) configuration and 40 km of uncompensated SSMF. A fair performance comparison is discussed in the experimental results considering B _G /B _w = 0.5 and B _G /B _w = 0.01 in the range of the optimized optical powers. It is shown that a maximum optical power penalty of approximately 2 dBm is registered according to a guard-band reduction from 50% to 1% of the useful bandwidth, for transmission over the 40 km of SSMF, considering 16-QAM subcarrier mapping.

The COVID-19 pandemic has detrimentally affected people’s lives and the economies of many countries, causing disruption in the health, education, transport, and other sectors. Several countries have implemented sanitary barriers at airports, bus and train stations, company gates, and other shared spaces to detect patients with viral symptoms in an effort to contain the spread of the disease. As fever is one of the most recurrent disease symptoms, the demand for devices that measure skin (body surface) temperature has increased. The thermal imaging camera, also known as a thermal imager, is one such device used to measure temperature. It employs a technology known as infrared thermography and is a noninvasive, fast, and objective tool. This study employed machine learning transfer using You Only Look Once (YOLO) to detect the hottest temperatures in the regions of interest (ROIs) of the human face in thermographic images, allowing the identification of a febrile state in humans. The algorithms detect areas of interest in the thermographic images, such as the eyes, forehead, and ears, before analyzing the temperatures in these regions. The developed software achieved excellent performance in detecting the established areas of interest, adequately indicating the maximum temperature within each region of interest, and correctly choosing the maximum temperature among them.

We report the experimental transmission of constant-envelope orthogonal frequency division multiplexing (CE-OFDM) signals over short-reach multimode fiber links. Error-free transmission of 2.2 Gb/s over a 300-m OM-3 fiber link, using a directly modulated 850-nm vertical-cavity surface emitting laser and direct detection, is achieved. The results confirm the CE-OFDM modulation format as a low peak-to-average power ratio alternative for low-cost data-center interconnects.

In the transition to electric mobility (EM), business model innovation plays a crucial role in expanding the use of electric vehicles and increasing acceptance of this technology. The transition pathways differ between countries in the largest economies and those in Latin America. Brazil presents a unique scenario, benefiting from an early start with biofuels, the production of flex-fuel vehicles, predominantly renewable electric energy generation (>80%), and the absence of a structured national policy aligned with local governments. This study introduces a framework that surveys and categorizes businesses in EM, relating them to sustainable development aspects and regulatory maturity. It builds a solid conceptual foundation, incorporating data from technical and commercial events, as well as interviews with Brazilian specialists for validation. The proposed framework aids in understanding the Brazilian context, identifying regulatory gaps, and developing a common language to advance studies on business model innovation, contributing to electromobility studies in Latin America. Additionally, it can guide the construction of regional and local public policies and help identify more sustainable projects.