• 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.
151

Framtida möjligheter för mobil styrning av hemmet : / Future possibilities for mobile control of electrical devices at home

Kääramees Vretblad, Oskar January 2012 (has links)
Målen med denna undersökning har varit att studera vilka tekniker som idag finns för att möjliggöra mobil styrning av hemmet och därigenom underlätta elanvändarens roll i en uppgradering av det befintliga elnätet, vilken/vilka tekniker som bör få störst betydelse för framtidens smarta hem, samt hur en implementering av en mobil applikation för fjärrstyrning av hemmet skulle kunna tas fram. Undersökningen har i första hand genomförts genom en omfattande förstudie och informationsinhämtning, genom jämförelser av för- och nackdelar mellan olika nätverkstekniker, samt genom utredande av lämplig utvecklingsmiljö baserat på tillgång till öppet utvecklar API, produkttillgänglighet och support, samt initialkostnad för utvecklingsverktyg och system för testning. Undersökningen har visat att det idag inte finns någon klar vinnare bland nätverksteknikerna på området, även om Zigbee, Z-Wave och Wi-Fi är de starkaste kandidaterna till att vinna stora marknadsandelar. Det är således inte uppenbart att någon teknik kommer att få mycket större utbredning än de övriga då teknikerna istället kan komma att komplettera varandra då de är starka på olika områden. Undersökningen har också visat att som utvecklingsmiljö är det svenska företaget Telldus produktlösning (Tellstick) en relativt billig och enkel produkt att använda för att komma igång med styrning av hemmet, samt att de tillhandahåller två öppna APIer och uppmuntrar tredjepartsutveckling av applikationer för deras system. / The objectives of this study has been to examine the techniques available for enabling home automation via mobile control (for instance via a smartphone) in order to facilitate the user's role in contributing to the upgrade of the present power-grid, but also to treat the matter of which of the techniques that will probably be of most importance for the future of the smart home, and how an implementation of a mobile application for remote home controlling could be developed. The investigation was primarily conducted through a comprehensive feasibility study of information gathering, comparison of the pros and cons of different networking techniques, and investigation of suitable development environments based on the availability of open developer APIs, availability of product solutions and support, and the cost of development tools for both development and system testing. The investigation has shown that there is currently no clear winner among the networking techniques in this area, although Zigbee, Z-Wave and Wi-Fi are the strongest candidates to gain large market shares. There is also no certainty that any technology will play a much greater role than the others since the techniques may complement each other because of their strength in different areas. The investigation also showed that as for a development environment the product solution developed by the Swedish company Telldus (called Tellstick) is relatively cheap and simple to use to get started with home automation, and that they encourage third party development by offering two open APIs for application development.
152

Adapting a DHT to a Self-Reliant M2M Network

Jimenez Bolonio, Jaime January 2011 (has links)
Machine-to-machine (M2M) communications is a field of research expected to grow in the following years. New business opportunities arise in this area, for instance the 50 Billion Project and the Future Internet Project at Ericsson. Thus new protocols and architectures need to be defined for the different scenarios where this technology is applicable. At the same time well known structured P2P networks, for instance by means of a Distributed Hash Table (DHT), present great synergy possibilities with M2M, in particular in the Wireless Sensor Networks (WSN) Area. M2M scenarios in which sensors become more autonomous and self-reliant, independent from a centralized decision-making entity can benefit from the use of DHTs. This thesis aims at adapting current DHT (Distributed Hash Table) procedures to a M2M (Machine-to-Machine) environment. Moreover it will consist on implementing a layer for M2M communication on top of an existing DHT. We analyze the state of the art in both sensor and P2P technologies. Based on that, we explain the motivations to create such a layer and the its benefits. Following the design we implement a fully working prototype and prepare some use case scenarios. Finally, we draw conclusions from the experience and trace future paths of research for our project.
153

A Proxy for Distributed Hash Table based Machine-to-Machine Networks

Li, Daoyuan January 2011 (has links)
Wireless sensor networks (WSNs) have been an increasingly interest for both researchers and entrepreneurs. As WSN technologies gradually matured and more and more use is reported, we find that most of current WSNs are still designed only for specific purposes. For example, one WSN may be used to gather information from a field and the collected data is not shared with other parties. We propose a distributed hash table (DHT) based machine-to-machine (M2M) system for connecting different WSNs together in order to fully utilize information collected from currently available WSNs. This thesis specifically looks at how to design and implement a proxy for such a system. We discuss why such a proxy can be useful for DHT-based M2M systems, what the proxy should consist of, and what kind of architecture is suitable. We also look into different communication protocols that can be used in these systems and discuss which ones best suit our purposes. The design of the proxy focuses on network management and service discovery of WSNs, and security considerations as well as caching mechanisms in order to improve performance. A prototype is implemented based on our design and evaluated. We find it feasible to implement such a DHT-based M2M system and a proxy in the system can be necessary and useful. Finally, we draw conclusions and discuss what future work remains to be done.
154

Investigation of Bluetooth Mesh and Long Range for IoT wearables

Nilsson, Mikael, Deknache, Hadi January 2018 (has links)
Dagens smarta enheter bygger nuförtiden allt mer på att ständigt hålla sig uppkopplade till allt inom dess omgivning. Industrier och hem innehåller alltmer små batteridrivna sensorer samt enheter som kommunicerar med varandra, dock är detta en begränsning när det gäller räckvidden av en enhet. Målet med denna uppsatsen är att undersöka användarbarhet av nya funktioner inom Bluetooth, samt belysa fördelar och nackdelar vilket kan uppstå med respektive teknologi när det gäller förlängd räckvidd. Vidare utfördes en jämförelsestudie, med målet att framföra skillnader för hur Bluetooth Mesh skiljer sig gentemot de andra Mesh teknologierna.Resultatet av denna uppsatsen visar att Bluetooth Mesh och Long-range har diverse svagheter och styrkor när det gäller olika användningsområden. Överföring av data med en högre hastighet och ett måttligt avstånd skulle vara tillräckligt för Long-range, medan Bluetooth Mesh anpassar sig mer för en större täckning och lättare dataöverföringar. / The smart devices of today are more and more dependent on being constantly connected to everything in its surrounding. Industries and homes contain more and more small battery powered sensors and devices, communicating with each other. However, there is a limitation when it comes to the range coverage of a device. The purpose of this thesis is to investigate the usefulness of the new features mesh networking and extended range for Bluetooth, as well as highlight the pros and cons that may exist with respective extended range technologies. Furthermore, a theoretical comparative study was conducted, with the aim of presenting some of the differences between Bluetooth Mesh and other common Mesh technologies. The results show that both Bluetooth Mesh and Long-range have strengths and weaknesses when it comes to different use cases. Transferring data with a bit higher throughput and a moderate distance would be suitable for a Long-range purpose, while Bluetooth Mesh is more suitable for a larger coverage and lighter data transfer.
155

Síťová architektura a propojování vestavěných systémů / Network Architecture and Interconnection of Embedded Systems

Trchalík, Roman January 2013 (has links)
The thesis focuses on the architecture of embedded systems. It summarizes the current state of accepted standards from IEEE 1451 family, which deals with creating an environment for the sensors and their involvement in various networks. These standards describe the open, network-independent communication architecture for a sensor-based system. One of the main outcomes of this work is the architectures presented as case studies, which can be used as design patters for embedded applications. They are demonstrated on ZigBee technology suitable mainly for small devices with very low power consumption. Based on these studies the new design of universal gateway was proposed. Its major advantage is that it allows interconnection of the endpoints based on different sensor network technologies. Additionally, the thesis deals with modifying the routing protocol of ZigBee network in order to reduce power consumption required to transmit one data packet.
156

Positioning System for Rescuing Missions in Underground Facilities : Wireless Network Implementation

Martínez Olivo, Alejandro January 2019 (has links)
In the case of an emergency in an underground facility, the harsh environment make the rescue missions a difficult and taxing task for the first responders. Disorientation, stress and lack of communication are fatal in that territory. In order to overcome all this difficulties and provide a system to coordinate and help locate emergency responders, a new Indoor Positioning System (IPS) is proposed. The system shall be scalable so it can expand its coverage over the site, it would adapt and remain reliable in the harsh conditions of the environment. The main goal of this project is to present an analysis of the current wireless technologies, their advantages and disadvantages and a comparison between them. Build a new solution and present the results of the performance of the network. The tests recreate the characteristics of the underground territory and present a good analysis of the system. This thesis project report the process, to build a scalable, adaptable and reliable wireless network to be used as the framework of a positioning system. The system is constructed using the ZigBee protocol stack and the nRF52840 hardware. A graphical user interface is developed to facilitate the configuration of the network. At the end the results gives proof that the system can be used in the underground facilities as long as the network is deployed carefully. / Vid en nödsituation i en underjordisk anläggning, på grund av den svåra miljön, räddningsuppdragen blir en svår och beskattande uppgift för de första svararna. Desorientering, stress och brist på kommunikation är dödliga inom det området. För att övervinna alla dessa svårigheter och tillhandahålla ett system för att samordna och hjälpa till att hitta nödlägen, föreslås ett nytt inomhuspositioneringssystem (IPS). Systemet ska vara skalbart så att det kan utöka sin täckning över webbplatsen, det skulle anpassa sig och förbli tillförlitligt under de svåra miljöerna. Detta arbete har huvudmål att presentera en analys av den nuvarande trådlösa tekniken, deras fördelar och nackdelar och en jämförelse mellan dem samtidigt bygga en ny lösning och presentera resultaten av nätverkets prestanda. Testen modellerar egenskaperna hos det underjordiska territoriet och presenterar en bra analys av systemet. Detta arbete rapporterar processen för att bygga ett skalbart, anpassningsbart och pålitligt trådlöst nätverk som ska användas som ett ramverk för ett positioneringssystem. Systemet är konstruerat med ZigBee-protokollstacken och hårdvaran nRF52840. Ett grafiskt användargränssnitt utvecklas för att underlätta konfigurationen av nätverket. Resultatet bevisar att systemet kan användas vid de underjordiska anläggningarna så länge nätverket distribueras noggrant.
157

Responding to Dangerous Accidents Among the Elderly: A Fall Detection Device with ZigBee-Based Positioning

Putnam, Michael R 01 September 2012 (has links) (PDF)
The following paper describes a fall detection and activity monitoring system with position detection based on Zigbee transceivers.The main objective is to reduce the time taken for emergency personnel to respond to falls among the elderly. Especially when the victim is unconscious or delirious, position tracking reduces location determination time within a busy hospital or nursing home environment and facilitates immediate treatment. Reduced response times correlate to decreased morbidity and mortality rates. Background is provided on the major wireless network advances currently deployed in a healthcare setting for asset and personnel tracking, etiology of falls, and several methods of detecting falls using sensors and image processing techniques. Data analysis proves that a precise coordinate tracking system was infeasible using the XBee RF module (based on the Zigbee protocol) due to environmental noise, a poor antenna construction and lack of precise signal strength measurements. A primitive scheme with lower resolution and higher reliability associating a single location with each Zigbee transceiver was employed. A pedometer function was added to the project to monitor the user’s daily activity and to potentially serve as a predictor of falls through the interpretation of mobility and gait patterns related to step counts.
158

Control of 3D-printed Hand Prosthetic via Intra-body Fat Channel Communication

Trollsås, Eric January 2022 (has links)
Intra-Body Communication (IBC) is a prospective technology where human tissue may be used as a signal medium in order to transmit useful data within the human body. Proposed applica- tions of this technology are prosthetics control or implanted device communication, potentially by establishing an Intra-Body Area Network (IBAN), which could further be enhanced by other IoT applications and 5G radio systems. Previous research at Uppsala University has shown the fat tissue to be a promising medium due to its low permittivity and loss tangent. This form of implementation is named Fat-IBC. This thesis aimed to produce a Fat-IBC enabled device, as a proof of concept. This project successfully produced and characterized phantom tissue, produced a basic demonstrator device in the form of a 3D-printed arm prosthetic, and integrated a wireless communication system into the arm prosthetic. The communication system was implemented using Arduino microcontrollers and XBee RF modules, based on the 802.15.4-based ZigBee protocol at 2.45 GHz. Muscle, fat, and skin phantom tissues were produced, with the muscle tissue being similar to other comparable tissue samples, while the fat and skin tissues deviated from such samples. A signal loss transmission test measured a -67 dB loss over 20 cm of fat tissue. Several potential issues with production and measurement were discussed. The arm demonstrator device was also tested by transmitting the control signal across phantom fat tissue, being fully functional through 10cm of tissue, and of limited function across 20cm of tissue.
159

Case Study: Assessing the Security of a ZigBee Smart HomeNetwork

Saker, Robal, Abu Issa, Obaida January 2024 (has links)
Utilizing the ZigBee protocol is pervasive in the context of smart homes, offering substantial convenience to individuals. However, smart home devices commonly handle significant quantities of real-world information, potentially giving rise to concerns related to information leakage. Therefore, in this study, we assess the security of a ZigBee smart homenetworkbyidentifying potential vulnerabilities and conducting a penetration test on the network. In addition, this study compared the potential damage inflicted on the ZigBee network bytechnical and non-technical users. Identifying the potential vulnerabilities was carried out by following a systematic literature review approach, while the penetration testing method was conducted with the help of a case study. The smart home network consisted of a gateway, a smart light bulb, a temperature and humidity sensor, and a motion sensor. The results show a vulnerability in the ZigBee protocol where the technical user could compromise all the security keys. However, the non-technical user was not able to compromise the ZigBee network. Consequently, the security of ZigBee-based smart devices still needs to be further investigated and strengthened. Finally, we discussed the future of the ZigBee network and the optimal scenarios for deploying it.
160

Real-time Location with ZigBee Hardware

Franzese, Anthony L. 20 April 2011 (has links)
No description available.

Page generated in 0.038 seconds