A Survey on Multi-AP Coordination Approaches over Emerging WLANs: Future Directions and Open Challenges

Recent advancements in wireless local area network (WLAN) technology include IEEE 802.11be and 802.11ay, often known as Wi-Fi 7 and WiGig, respectively. The goal of these developments is to provide Extremely High Throughput (EHT) and low latency to meet the demands of future applications like as 8K videos, augmented and virtual reality, the Internet of Things, telesurgery, and other developing technologies. IEEE 802.11be includes new features such as 320 MHz bandwidth, multi-link operation, Multi-user Multi-Input Multi-Output, orthogonal frequency-division multiple access, and Multiple-Access Point (multi-AP) coordination (MAP-Co) to achieve EHT. With the increase in the number of overlapping APs and inter-AP interference, researchers have focused on studying MAP-Co approaches for coordinated transmission in IEEE 802.11be, making MAP-Co a key feature of future WLANs. Moreover, similar issues may arise in EHF bands WLAN, particularly for standards beyond IEEE 802.11ay. This has prompted researchers to investigate the implementation of MAP-Co over future 802.11ay WLANs. Thus, in this article, we provide a comprehensive review of the state-of-the-art MAP-Co features and their shortcomings concerning emerging WLAN. Finally, we discuss several novel future directions and open challenges for MAP-Co.Comment: The reason for the replacement of the previous version of the paper is due to a change in the author's list. As a result, a new version has been created, which serves as the final draft version before acceptance. This updated version contains all the latest changes and improvements made to the pape

Introduction to the Special Issue on the 2011 Tohoku Earthquake and Tsunami

The 11 March 2011 Tohoku earthquake (05:46:24 UTC) involved a massive rupture of the plate‐boundary fault along which the Pacific plate thrusts under northeastern Honshu, Japan. It was the fourth‐largest recorded earthquake, with seismic‐moment estimates of 3–5×10^(22)  N•m (M_w 9.0). The event produced widespread strong ground shaking in northern Honshu; in some locations ground accelerations exceeded 2g. Rupture extended ∼200  km along dip, spanning the entire width of the seismogenic zone from the Japan trench to below the Honshu coastline, and the aftershock‐zone length extended ∼500  km along strike of the subduction zone. The average fault slip over the entire rupture area was ∼10  m, but some estimates indicate ∼25  m of slip located around the hypocentral region and extraordinary slip of up to 60–80 m in the shallow megathrust extending to the trench. The faulting‐generated seafloor deformation produced a devastating tsunami that resulted in 5–10‐km inundation of the coastal plains, runup of up to 40 m along the Sanriku coastline, and catastrophic failure of the backup power systems at the Fukushima Daiichi nuclear power station, which precipitated a reactor meltdown and radiation release. About 18,131 lives appear to have been lost, 2829 people are still missing, and 6194 people were injured (as reported 28 September 2012 by the Fire and Disaster Management Agency of Japan) and over a half million were displaced, mainly due to the tsunami impact on coastal towns, where tsunami heights significantly exceeded harbor tsunami walls and coastal berms

Smart Handover with Predicted User Behavior using Convolutional Neural Networks for WiGig Systems

WiGig networks and 60 GHz frequency communications have a lot of potential for commercial and personal use. They can offer extremely high transmission rates but at the cost of low range and penetration. Due to these issues, WiGig systems are unstable and need to rely on frequent handovers to maintain high-quality connections. However, this solution is problematic as it forces users into bad connections and downtime before they are switched to a better access point. In this work, we use Machine Learning to identify patterns in user behaviors and predict user actions. This prediction is used to do proactive handovers, switching users to access points with better future transmission rates and a more stable environment based on the future state of the user. Results show that not only the proposal is effective at predicting channel data, but the use of such predictions improves system performance and avoids unnecessary handovers.Comment: Submitted to IEEE Networ

Preparação de l-carvona a partir de d-limoneno.

A l-carvona foi obtida a partir de d-limoneno, utilizando-se reação em três etapas: transformação do d-limoneno e nitrosocloreto de d-limoneno; conversão do nitrosocloreto de d-limoneno em l-carvoxima; hidrólise da l-carvoxima em l-carvona e purifricação de l-carvona por destilação a vácuo. A contribuição mais significativa do presente processo em relação aos existentes é ter sido feita a deidrocloração do nitrosocloreto de d-limoneno sem o uso de bases, procedendo-se a um aquecimento controlado (52 a 56oC) do comosto em solvente adequado, preferivelmente etanol. O rendimento líquido da tansformação do d-limoneno foi de 38 a 49% e o produto final satisfaz as especificações para o uso comercial, inclusive quanto às características de odor e sabor.bitstream/item/65439/1/CTAA-DOCUMENTOS-15-PREPARACAO-DE-L-CARVONA-A-PARTIR-DE-D-LIMONENO-FL-06778.pd

Linalol, principal componente químico dos óleos essenciais da folha da sacaca (Croton cajucara Benth) e da madeira do pau-rosa (Aniba duckei Kostermans).

Verificação, de forma exploratória, dos efeitos de nutrientes químicos e orgânicos no rendimento em óleo e no teor de linalol de sacaca cultivada na área experimental da Embrapa Amazônia Ocidental (Manaus-AM).bitstream/CPAA-2009-09/2734/1/Com_Tec_15.pd

Teores de princípios pungentes de algumas pimentas do gênero capsicum cultivadas no Brasil.

bitstream/item/65463/1/CTAA-DOCUMENTOS-19-TEORES-DE-PRINCIPIOS-PUNGENTES-DE-ALGUMAS-PIMENTAS-DO-GENEROS-CAPSICUM-CULTIVA.pd

Óleos essenciais de frutos cítricos cultivados no Brasil.

Foram estudados, quanto à composição química e constantes físico-químicas, dos óleos essenciais de 5 grupos de frutos cítricos cultivados no Brasil (laranja, limão, tangerina, bergamota e "grapefruit"), num total de 12 diferentes óleos de 32 amostras. Objetivou-se avaliar a qualidade desses óleos do ponto de vista químico e contribuir com subsídios para a padronização dos mesmos. Concluiu-se que, quanto à composição química e quanto aos valores das constantes de poder rotatório, índice de refração densidade, os óleos analisados apresentam características comparáveis aos valores citados pela literatura para óleos essenciais cítrico de diferentes origens geográficas.bitstream/item/65375/1/CTAA-DOCUMENTOS-007-OLEOS-ESSENCIAIS-DE-FRUTAS-CITRICAS-CULTIVADAS-NO-BRASIL-FL-06784A.pd