• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 84
  • 46
  • 44
  • 12
  • 9
  • 9
  • 6
  • 6
  • 5
  • 3
  • 1
  • 1
  • 1
  • Tagged with
  • 244
  • 112
  • 79
  • 70
  • 64
  • 63
  • 45
  • 34
  • 29
  • 28
  • 27
  • 22
  • 22
  • 21
  • 20
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
231

A fuzzy logic micro-controller enabled system for the monitoring of micro climatic parameters of a greenhouse

Sibiya, Malusi 10 1900 (has links)
Motivation behind this master dissertation is to introduce a novel study called " A fuzzy logic micro-controller enabled system for the monitoring of micro-climatic parameters of a greenhouse" which is capable of intelligently monitoring and controlling the greenhouse climate conditions in a preprogrammed manner. The proposed system consists of three stations: Sensor Station, Coordinator Station, and Central Station. To allow for better monitoring of the climate condition in the greenhouse, fuzzy logic controller is embedded in the system as the system becomes more intelligent with fuzzy decision making. The sensor station is equipped with several sensor elements such as MQ-7 (Carbon monoxide sensor), DHT11 (Temperature and humidity sensor), LDR (light sensor), grove moisture sensor (soil moisture sensor). The communication between the sensor station and the coordinator station is achieved through XBee wireless modules connected to the Arduino Mega and the communication between coordinator station and the central station is also achieved via XBee wireless modules connected to the Arduino Mega. The experiments and tests of the system were carried out at one of IKHALA TVET COLLEGE’s greenhouses that is used for learning purposes by students studying agriculture at the college. The purpose of conducting the experiments at the college’s green house was to determine the functionality and reliability of the designed wireless sensor network using ZigBee wireless technology. The experiment result indicated that XBee modules could be used as one solution to lower the installation cost, increase flexibility and reliability and create a greenhouse management system that is only based on wireless nodes. The experiment result also showed that the system became more intelligent if fuzzy logic was used by the system for decision making. The overall system design showed advantages in cost, size, power, flexibility and intelligence. It is trusted that the results of the project will give the chance for further research and development of a low cost greenhouse monitoring system for commercial use. / Electrical and Mining Engineering / M. Tech. (Electrical Engineering)
232

Development of a remote wireless monitoring system for large farms

Rootman, Adriaan Cornelius January 2012 (has links)
Thesis submitted in fulfilment of the requirements for the degree Master of Technology: Electrical Engineering at the Cape Peninsula University of Technology, 2012 / This research project addresses the unique challenges of extensive farming in terms of monitoring and controlling remote equipment or events. Poorly maintained roads and escalating fuel costs increase difficulty of farming and the time spent on physically monitoring remote sites further reduces financial yields. The research showed that there are very few solutions that implement wireless or electronic technology to overcome the challenges associated with these isolated and arid areas and that a low-cost, long range wireless telemetry solution that is easy to use would be beneficial for the extensive farming industry. It was therefore the aim of this project to develop a remote monitoring and controlling solution that implements wireless technology to convey information of activities around the farm utilising electronic means. To be able to successfully develop a wireless telemetry solution that will accurately meet the needs of this specific sector of industry, market research was conducted. To guide the research, the QFD (quality function deployment) process for product development has been implemented. The research consisted out of various aspects including a survey, financial considerations and international comparisons. The research also aided in the understanding of the day-to-day activities and also the physical parameters of extensive farms. Also, currently available technologies and products were evaluated to establish whether similarities exist that will aid in the development of a new product. The development process was based on the results obtained in the market research and resulted in a wireless telemetry solution that overcame all the design challenges and proved to be technically feasible, successfully addressing the application requirements. Zigbee technology was utilized for wireless communication because it provided an off-the-shelf solution with a number of readily available development platforms from various technology providers. A communication range of up to 6 kilometres with a transmitted power of 11dBm was achieved for point-to-point communication and a mesh network topology has been implemented for even longer range and complete coverage on farms. Various types of measurements have been catered for, with custom-designed instrumentation which enabled measurements such as water levels, movement and analogue signals. Also, a basic user interface was developed to enable the user to monitor or control the equipment or events remotely from a personal computer, locally or even over the internet. The results of this research project showed that by carefully selecting available technologies and understanding the application, it is possible to develop a solution that addresses the monitoring and controlling needs associated with extensive farming. The wireless telemetry system that was developed resulted in a saving equal to 10% of the total expenses of the farms per year. The telemetry system is therefore a financially feasible solution with a payback period of less than 1 year and far below the initial estimated budget. Without the need to physically monitoring equipment and events, an increase in productivity and the expansion of the overall enterprise is a further benefit added unto the monetary savings. In addition to the financial benefits of implementing new wireless technology, this is an opportunity to contribute to a cleaner and more sustained future as a legacy for the next generation by reducing the carbon footprint of the farm.
233

Wireless IO : A wireless accessory for integration of an Axis Communications camera in a sensor network.

Eriksson, Hannes, Brange Sollie, Ivan January 2017 (has links)
When installing new network security cameras in buildings, the cameras are often connected to sensors via signal wires. Since most building already have internet and electricity drawn throughout the structure, the procedure of routing a new signal wire can be costly and time demanding. By replacing this wire with a wireless link, the cost and time it takes for the customer to install a camera could be reduced. The objective for this thesis is to investigate different wireless technologies used in short range, low power wireless communication networks such as PANs and LANs. Focusing on technologies used in the surveillance segment a decision will be made on which wireless technology that would suit as a link between a sensor and a camera for transmitting trigger signals. The technology will then be implemented in a proof-of-concept accessory, which can give an Axis Communications camera wireless functionality through it’s IO port.
234

Internet of Things zařízení s podporou ZigBee a 6LoWPAN / Internet of Things Device Based on ZigBee and 6LoWPAN

Halász, Dávid January 2016 (has links)
Internet of Things is the latest phenomenon in the computing industry. Even if it has not been completely defined yet, we are already surrounded by various devices connected to the Internet. This thesis project focuses on low cost and low-power wireless solutions and on the on-line backend behind the architecture. At the same time the present work also deals with Cloud Computing which can provide a highly scalable runtime environment for this backend without building an infrastructure. To handle the huge amount of data collected by billions of devices, BigData services could be used in the same cloud space. The project is a collection of the theoretical background of the Internet of Things; so as a result, it provides the reader with an overview of the concept. It also provides a walktrough of the design, implementation and testing process of a complex agricultural Internet of Things solution.
235

Internet of Things / Internet of Things

Piškula, David January 2019 (has links)
This thesis focuses on the Internet of Things and some of the most important problems it faces today. Among these are the overdependence on the Cloud and lack of autonomy, poor security and privacy, complicated initialization and power consumption. The work aims to implement a complex IoT solution that solves the discussed problems. The project is part of a collaboration with NXP Semicondutors and will be used to showcase the company's technologies.
236

Bezdrátové zabezpečovací zařízení / Wireless Security and Surveillance System

Výborný, Jiří January 2008 (has links)
This Master’s thesis deals with design and construction of a wireless security and surveillance system in ZigBee wireless networks (IEEE802.15.4). The design consists of creating a star network topology with intended monitoring of home area via end device boards paired with coordinator board, which provides basic networking functionality. End device is used to send data from a temperature sensor DS1631 and magnetic reed switches to coordinator. ZigBee module ZDM-A1281-A2 made by MeshNetics company embedded on each board contains a micro controller ATMega1281 and a transceiver AT86RF230 working in a 2,4GHz frequency band. System is able to notice of any door or window move actions and too high temperature. The non-fully functional ZigBee stack, which is called an Open MAC software, based on MAC (Media Access Control ) layer and PHY (Physical) layer from MeshNetics, has been used to develop the user software. Open MAC consists of three application samples in C code. One of them was modified by the user for an application of communication between the module and sensors. The same design with module RC2204AT made by Radiocrafts company was tested as well, but it couldn’t be executed. All developed boards have been constructed and tested via Terminal PC program.
237

Bezpečnostní a monitorovací systém rodinného domu / Home Security and Monitoring System

Valach, Lukáš January 2016 (has links)
The thesis elaborates on an implementation of wireless home security system. The wireless communication utilizes IEEE 802.15.4 radios and ZigBee communication protocol. The beginning of the thesis provides specification of the intended system followed by an evaluation of usable energy harvesting solutions and later by consideration of single board computer systems suitable for implementation of the control node of the sensor network. The rest of the thesis describes design, implementation and testing of particular components of the security system. Conclusion evaluates the achieved goals and offers suggestions for future work. The end products of the thesis are physical devices implementing wireless sensor nodes, control unit of the security system as well as a graphical user interface for the system management.
238

Bezdrátový systém pro vyhodnocení řízení osvětlení v budovách s cílem získat informace vedoucí k úsporám / Wireless System for Evaluation of Lighting Control in Buildings for Obtaining Information Leading to Savings

Malinowski, Radim January 2015 (has links)
The aim of the thesis is to design a system based on wirelessly comunicating devices that will be able to record an information about persons presesce in certain area. Aquired data will served for evaluation of the area lighting system efficiency. Partial goals related to this work are: to analyze electricity consumption mesaurement methods, to analyze presence and movement detection methods, to analzye wireless communication methods, to desin system's HW and SW including realization, to put system into a real operation and finally, to evaluate measured data.
239

Optimizing Cloudlet Scheduling and Wireless Sensor Localization using Computational Intelligence Techniques

Al-Olimat, Hussein S. 19 December 2014 (has links)
No description available.
240

Architecture de réception RF très faible coût et très faible puissance. Application aux réseaux de capteurs et au standard Zigbee

Camus, Manuel 29 January 2008 (has links) (PDF)
Le travail présenté ici s'inscrit dans la perspective du développement de modules électroniques à très faible coût et à très faible consommation pour les réseaux de capteurs sans fils (WSN). Il traite de la conception et du test d'une chaîne de réception RF compatible avec la norme IEEE 802.15.4 pour la bande ISM 2.4GHz. L'interface RF objet de notre étude inclue toutes les fonctions depuis l'antenne jusqu'au 1er étage du filtre analogique en bande de base, à partir duquel le gain devient suffisant pour masquer le bruit introduit par le reste de la chaîne de réception. Ce mémoire articulé autour de quatre chapitres, décrit toutes les étapes depuis la définition des spécifications de la chaîne de réception jusqu'à la présentation de ses performances, en passant par l'étude de son architecture et la conception de ses différents étages. Suite à l'étude de l'impact des interféreurs IEEE 802.15.4 et IEEE 802.11b présents dans la bande ISM 2.4GHz, une architecture utilisant une fréquence intermédiaire de 6MHz a été retenue. En outre, pour pouvoir répondre aux spécifications fixées, cette architecture est composée de plusieurs étages innovants ou originaux tels qu'un balun intégré trois accès, un amplificateur faible bruit sans inductance, un mélangeur passif piloté par un signal local (OL) à très faible rapport cyclique ainsi qu'un filtre bande de base optimisé en bruit et en linéarité. Intégré dans une technologie CMOS 90nm, ce récepteur occupe une surface de 0.07mm², ou 0.23mm² en incluant le balun intégré, qui représente une réduction de 70% par rapport à l'état de l'art des puces compatibles avec le standard IEEE 802.15.4. En prenant en compte la consommation dynamique de toute la chaîne de mise en forme du signal OL, la tête de réception précédemment décrite consomme seulement 4mA sous une tension d'alimentation de 1.35V. Enfin, en incluant le balun intégré, le gain est de 35dBv/dBm, le facteur de bruit de 7.5dB, l'IIP3 de -10dBm et la réjection d'image supérie ure à 32dB. Ces performances placent ce récepteur parmi les récepteurs RF les plus performants pour cette application. Les nombreux principes mis en Suvre sont par ailleurs transposables à d'autres bandes de fréquences et à d'autres standards de communication.

Page generated in 0.0244 seconds