2 research outputs found
Edge of the network device for a low power wide area network
Dissertação de mestrado em Engenharia Eletrónica Industrial e ComputadoresThe widespread of Internet connection, particularly on small devices (embedded systems), has
allowed the development of the Internet of Things (IoT) concept, due to the connection of these
devices to web micro services (Cloud), and has had a major role in Industry 4.0 [1]. Through
the advances of wireless technologies, these devices were able to have an Internet connection,
becoming available everywhere. The creation of Wireless Sensor Networks (WSNs) has enabled
the use of networks composed of independent devices (nodes or edge devices), equipped with
sensors and actuators, and made it possible to collect information about the environment where
they are deployed [2].
The growing necessity of having a wider coverage area for Wireless Sensor Networks, along
with the demanding low power requirements on devices has enabled Low Power Wide Area (LPWA)
technologies to arise. These technologies are able to reach further coverage than conventional
wireless technologies (such as Bluetooth, Wi-Fi, ZigBee etc), as well as raising the energy autonomy
of the devices [3], which makes LPWA technologies ideal for wider areas.
The recent tragedies of wildfires in Portugal, in both 2017 and 2018, had great impact on
economic and social levels. Early detection and alerts about wildfires are crucial to prevent them
from spreading [4]. Therefore, by using LPWA technologies in forests, a case study can be made
for the wildfire occurrences in forests. Through the use of independent devices equipped with
sensors, data can be collected from the environment that might detect that a fire is starting, and
then send alerts to fire fighting units.
In this Master’s thesis it was developed the architecture of sensor nodes, to be integrated in
a Low Power Wide Area Network (LPWAN). By using the LoRa technology to achieve a long range
between the sensor nodes and the network coordinator, it is possible for edge devices to collect
and send data to upper levels of the network.
It was possible to gather information about the environment and further understand LoRa’s
potential for sending all the data to the upper levels of the network.A proliferação da conexão à Internet, especialmente em pequenos dispositivos (sistemas embebidos),
permitiu o desenvolvimento do conceito Internet of Things (IoT), devido à possibilidade
de ligação destes a micro serviços web (Cloud), tendo um papel crucial no desenrolar da Indústria
4.0 [1]. Tendo como principal impulsionador o avanço tecnológico das redes sem fios,
foi possível ligar estes dispositivos à Internet, tornando-os acessíveis em qualquer lado. Assim,
surgiram as Wireless Sensor Networks (WSNs), através da utilização de redes de dispositivos
independentes (nós ou edge devices), equipados com sensores e atuadores, possibilitando a
recolha de informação sobre o meio onde estão colocados [2].
A crescente necessidade de cobrir áreas cada vez maiores para este tipo de redes, associada
a requisitos mais exigentes de consumo energético reduzido nos dispositivos, abriu caminho para
o aparecimento das tecnologias Low Power Wide Area (LPWA). Este tipo de tecnologias consegue
alcances superiores em relação às redes sem fios convencionais (Wi-Fi, Bluetooth, entre outros),
permitindo maior autonomia dos nós sensores [3], tornando-se assim ideais para a sua utilização
em áreas alargadas.
As recentes tragédias de incêndios que ocorreram em Portugal, em particular nos anos
de 2017 e 2018, tiveram grande impacto tanto a nível económico como social. A deteção e
alerta precoce de incêndios são fatores cruciais para evitar a sua propagação [4]. Utilizando as
tecnologias LPWA em contexto florestal poderá criar-se um caso de estudo para a ocorrência de
incêndios em florestas. Através da utilização de edge devices, poderá ser possível recolher dados
provenientes deste meio que indiquem a existência de um incêndio a deflagrar, e enviar alertas
para as unidades de combate a incêndios.
Nesta dissertação foi desenvolvida a arquitetura dos nós sensores, a serem integrados numa
Low Power Wide Area Network (LPWAN). Utilizando tecnologia LoRa para obter um longo alcance
entre os nós e o coordenador da rede, poderá desta forma ser possível os nós sensores recolherem
e enviarem dados para as camadas superiores.
Foi possível, com a utilização de sensores nos nós, recolher informações sobre o ambiente e
perceber o potencial da tecnologia LoRa para o envio destes dados para as camadas superiores
Characterisation of microbial attack on archaeological bone
As part of an EU funded project to investigate the factors influencing bone preservation in the archaeological record, more than 250 bones from 41 archaeological sites in five countries spanning four climatic regions were studied for diagenetic alteration. Sites were selected to cover a range of environmental conditions and archaeological contexts. Microscopic and physical (mercury intrusion porosimetry) analyses of these bones revealed that the majority (68%) had suffered microbial attack. Furthermore, significant differences were found between animal and human bone in both the state of preservation and the type of microbial attack present. These differences in preservation might result from differences in early taphonomy of the bones. © 2003 Elsevier Science Ltd. All rights reserved