137 research outputs found

    A Wireless Sensor Network for Vineyard Monitoring That Uses Image Processing

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    The first step to detect when a vineyard has any type of deficiency, pest or disease is to observe its stems, its grapes and/or its leaves. To place a sensor in each leaf of every vineyard is obviously not feasible in terms of cost and deployment. We should thus look for new methods to detect these symptoms precisely and economically. In this paper, we present a wireless sensor network where each sensor node takes images from the field and internally uses image processing techniques to detect any unusual status in the leaves. This symptom could be caused by a deficiency, pest, disease or other harmful agent. When it is detected, the sensor node sends a message to a sink node through the wireless sensor network in order to notify the problem to the farmer. The wireless sensor uses the IEEE 802.11 a/b/g/n standard, which allows connections from large distances in open air. This paper describes the wireless sensor network design, the wireless sensor deployment, how the node processes the images in order to monitor the vineyard, and the sensor network traffic obtained from a test bed performed in a flat vineyard in Spain. Although the system is not able to distinguish between deficiency, pest, disease or other harmful agents, a symptoms image database and a neuronal network could be added in order learn from the experience and provide an accurate problem diagnosis

    Application of Wireless Nano Sensors Network and Nanotechnology in Precision Agriculture: Review

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    Due to a series of global issues in recent years, such as the food crisis, the impact of fertilizer on climate change, and improper use of irrigation that’s way precision agriculture is the best solution for alleviating this problem. One of the most important and interesting information technology is the wireless Nanosensor network with the help of Nanotechnology will boost crop productivity, maintain the fertility status of the soil, save the water with precise application of irrigation in the field and minimize the loss of excess fertilizer through the precise application. In this paper, we have surveyed the importance of sensor networks in precision agriculture and the importance of Nanosensors with the help of Nanotechnology for remote monitoring in the various application of the agriculture field. View Article DOI: 10.47856/ijaast.2022.v09i04.00

    Irrigation planning system for agricultural soils

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    Dissertação de mestrado integrado em Engenharia Eletrónica Industrial e ComputadoresO objetivo principal desta dissertação é o desenvolvimento de um sistema de planeamento de regas para a agricultura. Este projeto dá seguimento ao algoritmo desenvolvido em [1], capaz de criar um plano de rega de acordo com informações relativas ao solo, colheita, tipo de irrigação, humidade do solo e a previsão meteorológica de uma determinada localização. O sistema desenvolvido é composto por uma aplicação web e uma rede de dispositivos eletrónicos no campo. O sistema efetua todo o trabalho necessário, desde a aquisição de dados relativos à humidade do solo até à exibição dos planos de rega ao agricultor. A aplicação web utiliza a stack tecnológica MERN para fornecer uma interface ao utilizador, onde é possível gerir os pontos de rega e campos agrícolas, observar previsões meteorológicas e visualizar e obter atualizações relativas aos planos de rega, assim como alertar o agricultor através de noti ficações push quando condições alarmantes se verificam. Para além da interface com o utilizador, esta também obtém informações meteorológicas, executa o algoritmo de planeamento e agrega os dados de humidade do solo recolhidos pela rede de pontos de rega, através de um servidor CoAP. A rede de dispositivos eletrónicos no campo está encarregue de recolher informação relativa à humidade do solo e enviá-la para o servidor de hora a hora, recorrendo a diferentes tecnologias de forma a proporcionar uma solução flexível de baixo custo, com duas possibilidades de configuração, standalone e WSN, adequadas para diferentes cenários. A comunicação entre os dispositivos no campo e o servidor é baseada no protocolo CoAP. A configuração standalone é constituída por uma PCB, que combina um microntrolador low power com um circuito de energy harvesting. A esta, são conectados um painel solar, um conversor step-up, uma bateria Li-Po e um módulo de comunicações móveis (capaz de utilizar as tecnologias móveis GPRS/UMTS e NB-IoT), assim como até seis sensores de humidade do solo. A configuração WSN recorre à mesma PCB que a configuração standalone, utilizando um trans ceiver LoRa em vez do módulo de comunicações móveis. Esta comunica através da camada física LoRa com um edge device baseado na plataforma Raspberry Pi, que encaminha os pacotes rece bidos pela rede LoRa através do protocolo CoAP para o servidor. A rede LoRa desenvolvida é capaz de enviar mensagens downlink diárias e um data-rate adaptativo, que controla o link budget através do spreading factor e da potência de transmissão, recebendo pacotes recorrendo a um esquema adaptativo de seleção do spreading factor (ASFS) [2].The main objective of this dissertation is the development of an irrigation planning system for agri culture. This work builds upon the algorithm developed in [1], capable of creating an irrigation plan according to soil, crop, irrigation, soil moisture and weather forecast of a given location. The developed system is composed by a web application and a network of field electronic devices. The system does all the necessary work, from the retrieval of the soil moisture data to the display of irrigation prescription plans to the farmer. The web application resorts to the MERN technological stack to provide an interface to the farmer, where irrigation points and crop fields can be managed, forecasts observed and the irrigation plans can be retrieved and updated, while also alerting the farmer through push notifications when danger ous conditions are verified. Besides the interface with the farmer, it also gathers weather information, performs the irrigation planning and retrieves soil moisture data from the irrigation points through a CoAP server. The network of electronic devices is in charge of retrieving soil moisture information and sending it to the server on an hourly basis, using different technologies to provide a flexible low-cost solution with two different configurations, standalone and WSN, suitable to many different scenarios. The communication between field devices and the server is based on CoAP protocol. The standalone configuration consists of a PCB, where a low power microcontroller is paired with an energy harvesting circuit. To it, a solar panel, a step-up converter, Li-Po battery and a cellular communication module (capable of connectivity with both GPRS/UMTS and NB-IoT technologies) are connected, along with up to six soil moisture sensors. The WSN configuration makes use of the same PCB as the standalone configuration, using a LoRa transceiver instead. It communicates through the LoRa physical layer to an edge device based on the Raspberry Pi platform, which forwards the packets received from the LoRa network through CoAP to the web server. The LoRa network developed is capable of daily downlink messages and adaptive data-rate, where the link budget is controlled through the spreading factor and the transmission power, receiving packets through an adaptive spreading factor selection (ASFS) scheme [2].Firstly, I would like to show my gratitude to my advisors for their guidance and support during this project, and in particular to Professor Doctor Sérgio Lopes for the insightful discussions and dedication over the course of this work. I also would like to thank everyone involved in the research project 02/SAICT/2017-28247-FCT-TO-CHAIR, that supported the work developed in this dissertation

    Power Optimization for Wireless Sensor Networks

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    Keberkesanan program simulasi penapis sambutan dedenyut terhingga (FIR) terhadap kefahaman pelajar kejuruteraan elektrik

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    Kefahaman merupakan aset bagi setiap pelajar. Ini kerana melalui kefahaman pelajar dapat mengaplikasikan konsep yang dipelajari di dalam dan di luar kelas. Kajian ini dijalankan bertujuan menilai keberkesanan program simulasi penapis sambutan dedenyut terhingga (FIR) terhadap kefahaman pelajar kejuruteraan elektrik FKEE, UTHM dalam mata pelajaran Pemprosesan Isyarat Digital (DSP) bagi topik penapis FIR. Metodologi kajian ini berbentuk kaedah reka bentuk kuasi�eksperimental ujian pra-pasca bagi kumpulan-kumpulan tidak seimbang. Seramai 40 responden kajian telah dipilih dan dibahagi secara rawak kepada dua kllmpulan iaitu kumpulan rawatan yang menggunakan program simulasi penapis FIR dan kumpulan kawalan yang menggunakan kaedah pembelajaran berorientasikan modul pembelajaran DSP UTHM. Setiap responden menduduki dua ujian pencapaian iaitu ujian pra dan ujian pasca yang berbentuk kuiz. Analisis data berbentuk deskriptif dan inferens dilakllkan dengan menggunakan Peri sian Statistical Package for Social Science (SPSS) versi 11.0. Dapatan kajian menunjukkan kedua-dua kumpulan pelajar telah mengalami peningkatan dari segi kefahaman iaitu daripada tahap tidak memuaskan kepada tahap kepujian selepas menggunakan kaedah pembelajaran yang telah ditetapkan bagi kumpulan masing-masing. Walaubagaimanapun, pelajar kumpulan rawatan menunjukkan peningkatan yang lebih tinggi sedikit berbanding pelajar kumpulan kawalan. Namun begitu, dapatan kajian secara ujian statistik menunjukkan tidak terdapat perbezaan yang signifikan dari segi pencapaian markah ujian pasca di antara pelajar kumpulan rawatan dengan pelajar kumpulan kawalan. Sungguhpun begitu, penggunaan program simulasi penapis FIR telah membantu dalam peningkatan kefahaman pelajar mengenai topik penapis FIR

    QoS BASED ENERGY EFFICIENT ROUTING IN WIRELESS SENSOR NETWORK

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    A Wireless Sensor Networks (WSN) is composed of a large number of low-powered sensor nodes that are randomly deployed to collect environmental data. In a WSN, because of energy scarceness, energy efficient gathering of sensed information is one of the most critical issues. Thus, most of the WSN routing protocols found in the literature have considered energy awareness as a key design issue. Factors like throughput, latency and delay are not considered as critical issues in these protocols. However, emerging WSN applications that involve multimedia and imagining sensors require end-to-end delay within acceptable limits. Hence, in addition to energy efficiency, the parameters (delay, packet loss ratio, throughput and coverage) have now become issues of primary concern. Such performance metrics are usually referred to as the Quality of Service (QoS) in communication systems. Therefore, to have efficient use of a sensor node’s energy, and the ability to transmit the imaging and multimedia data in a timely manner, requires both a QoS based and energy efficient routing protocol. In this research work, a QoS based energy efficient routing protocol for WSN is proposed. To achieve QoS based energy efficient routing, three protocols are proposed, namely the QoS based Energy Efficient Clustering (QoSEC) for a WSN, the QoS based Energy Efficient Sleep/Wake Scheduling (QoSES) for a WSN, and the QoS based Energy Efficient Mobile Sink (QoSEM) based Routing for a Clustered WSN. Firstly, in the QoSEC, to achieve energy efficiency and to prolong network/coverage lifetime, some nodes with additional energy resources, termed as super-nodes, in addition to normal capability nodes, are deployed. Multi-hierarchy clustering is done by having super-nodes (acting as a local sink) at the top tier, cluster head (normal node) at the middle tier, and cluster member (normal node) at the lowest tier in the hierarchy. Clustering within normal sensor nodes is done by optimizing the network/coverage lifetime through a cluster-head-selection algorithm and a sleep/wake scheduling algorithm. QoSEC resolves the hot spot problem and prolongs network/coverage lifetime. Secondly, the QoSES addressed the delay-minimization problem in sleep/wake scheduling for event-driven sensor networks for delay-sensitive applications. For this purpose, QoSES assigns different sleep/wake intervals (longer wake interval) to potential overloaded nodes, according to their varied traffic load requirement defined a) by node position in the network, b) by node topological importance, and c) by handling burst traffic in the proximity of the event occurrence node. Using these heuristics, QoSES minimizes the congestion at nodes having heavy traffic loads and ultimately reduces end-to-end delay while maximizing the throughput. Lastly, the QoSEM addresses hot spot problem, delay minimization, and QoS assurance. To address hot-spot problem, mobile sink is used, that move in the network to gather data by virtue of which nodes near to the mobile sink changes with each movement, consequently hot spot problem is minimized. To achieve delay minimization, static sink is used in addition to the mobile sink. Delay sensitive data is forwarded to the static sink, while the delay tolerant data is sent through the mobile sink. For QoS assurance, incoming traffic is divided into different traffic classes and each traffic class is assigned different priority based on their QoS requirement (bandwidth, delay) determine by its message type and content. Furthermore, to minimize delay in mobile sink data gathering, the mobile sink is moved throughout the network based on the priority messages at the nodes. Using these heuristics, QoSEM incur less end-to-end delay, is energy efficient, as well as being able to ensure QoS. Simulations are carried out to evaluate the performance of the proposed protocols of QoSEC, QoSES and QoSEM, by comparing their performance with the established contemporary protocols. Simulation results have demonstrated that when compared with contemporary protocols, each of the proposed protocol significantly prolong the network and coverage lifetime, as well as improve the other QoS routing parameters, such as delay, packet loss ratio, and throughput

    Sustainable modular IoT solution for smart cities applications supported by machine learning algorithms

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    The Internet of Things (IoT) and Smart Cities are nowadays a big trend, but with the proliferation of these systems several challenges start to appear and put in jeopardy the acceptance by the population, mainly in terms of sustainability and environmental issues. This Thesis introduces a new system composed by a modular IoT smart node that is self-configurable and sustainable with the support of machine learning techniques, as well as the research and development to achieve a innovative solution considering data analysis, wireless communications and hardware and software development. For all these, concepts are introduced, research methodologies, tests and results are presented and discussed as well as the development and implementation. The developed research and methodology shows that Random Forest was the best choice for the data analysis in the self-configuration of the hardware and communication systems and that Edge Computing has an advantage in terms of energy efficiency and latency. The autonomous communication system was able to create a 65% more sustainable node, in terms of energy consumption, with only a 13% decrease in quality of service. The modular approach for the smart node presented advantages in the integration, scalability and implementation of smart cities projects when facing traditional implementations, reducing up to 45% the energy consumption of the overall system and 60% of messages exchanged, without compromising the system performance. The deployment of this new system will help Smart Cities, in a worldwide fashion, to decrease their environmental issues and comply with rules and regulations to reduce CO2 emission.A Internet das Coisas (IoT) e as Cidades Inteligentes são hoje uma grande tendência, mas com a rápida evolução destes sistemas são vários os desafios que põem em causa a sua aceitação por parte das populações, maioritariamente devido a problemas ambientais e de sustentabilidade. Esta Tese introduz um novo sistema composto por nós de IoT inteligentes que são auto-configuáveis e sustentáveis suportados por de aprendizagem automática, e o trabalho de investigação e desenvolvimento para se obter uma solução inovadora que considera a análise de dados, comunicações sem fios e o desenvolvimento do hardware e software. Para todos estes, os conceitos chave são introduzidos, as metodologias de investigação, testes e resultados são apresentados e discutidos, bem como todo o desenvolvimento e implementação. Através do trabalho desenvolvido mostra-se que as Árvores Aleatórias são a melhor escolha para análise de dados em termos da autoconfiguração do hardware e sistema de comunicações e que a computação nos nós tem uma vantagem em termos de eficiência energética e latência. O sistema de configuração autónoma de comunicações foi capaz de criar um nós 65% mais sustentável, em termos en- ergéticos, comprometendo apenas em 13% a qualidade do servi ̧co. A solução modular do nó inteligente apresentou vantagens na integração, escalabilidade e implementação de projectos para Cidades Inteligentes quando comparado com soluções tradicionais, reduzindo em 45% o consumo energético e 60% a troca de mensagens, sem comprometer a qualidade do sistema. A implementação deste novo sistema irá ajudar as cidades inteligentes, em todo o mundo, a diminuir os seus problemas ambientais e a cumprir com as normas e regulamentos para reduzir as emissões de CO2

    A Sybil attack detection scheme for a forest wildfire monitoring application

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    © 2016 Elsevier B.V. Wireless Sensor Networks (WSNs) have experienced phenomenal growth over the past decade. They are typically deployed in human-inaccessible terrains to monitor and collect time-critical and delay-sensitive events. There have been several studies on the use of WSN in different applications. All such studies have mainly focused on Quality of Service (QoS) parameters such as delay, loss, jitter, etc. of the sensed data. Security provisioning is also an important and challenging task lacking in all previous studies. In this paper, we propose a Sybil attack detection scheme for a cluster-based hierarchical network mainly deployed to monitor forest wildfire. We propose a two-tier detection scheme. Initially, Sybil nodes and their forged identities are detected by high-energy nodes. However, if one or more identities of a Sybil node sneak through the detection process, they are ultimately detected by the two base stations. After Sybil attack detection, an optimal percentage of cluster heads are elected and each one is informed using nomination packets. Each nomination packet contains the identity of an elected cluster head and an end user's specific query for data collection within a cluster. These queries are user-centric, on-demand and adaptive to an end user requirement. The undetected identities of Sybil nodes reside in one or more clusters. Their goal is to transmit high false-negative alerts to an end user for diverting attention to those geographical regions which are less vulnerable to a wildfire. Our proposed approach has better network lifetime due to efficient sleep–awake scheduling, higher detection rate and low false-negative rate

    Security for constrained IoT devices

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    Tese de mestrado, Segurança Informática, Universidade de Lisboa, Faculdade de Ciências, 2020In the recent past the Internet of Things has been the target of a great evolution, both in terms of applicability and of use. Society increasingly wants to use and massify the IoT to obtain information and act in the environment, for example, to remotely control an irrigation system. The reduction in the cost of devices and the constant evolution of personal mobile devices has largely contributed to their spread. However, its implementation is carried out in adverse environments and outside the typical information systems. The devices are, as a rule, limited in terms of resources, both computation and memory. The applicability to the IoT of the security techniques already known to conventional systems has therefore to be adapted, because it does not take into account the characteristics of the resources of the devices and require additional load when exchanging messages between these system elements. In addition, the development of applications is difficult because there is not yet developed tools and standards as there are for the traditional HTTPS or TLS when considering conventional systems. In this work, we intend to present a prototype of a low-cost solution (compared to existing equivalent solutions) that uses a secure communication channel based on standard protocols. An application is also developed based on technologies more familiar to programmers, similar to traditional Web development. We took into account the ”Green By Web” project as a case study. We have concluded that it is possible to have a secure communication, using UDP/DTLS over the CoAP protocol. With this approach we optimized the number of exchanged messages between the client and the server to be up to 8 times less and their size to be up to 10%, comparing against applications that use TCP/TLS connections, such as web applications that use HTTPS. This allows the energy spent by the low-cost components to be lower and increases their battery lifetime

    Crop Management with the IoT: an Interdisciplinary Survey

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    In this study we analyze how crop management is going to benefit from the Internet of Things providing an overview of its architecture and components from an agronomic and a technological perspective. The present analysis highlights that IoT is a mature enabling technology, with articulated hardware and software components. Cheap networked devices may sense crop fields at a finer grain, to give timeliness warnings on stress conditions and the presence of disease to a wider range of farmers. Cloud computing allows to reliably store and access heterogeneous data, developing and deploy farm services. From this study emerges that IoT is also going to increase attention to sensor quality and placement protocol, while Machine Learning should be oriented to produce understandable knowledge, which is also useful to enhance Cropping System Simulation systems
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