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  • 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.
421

Um estudo para o problema de ordenação total de mensagens aplicado a redes Bluetooth com restrições fracas de tempo real / A study to total order message problem applied to Bluetooth networks using real time weak constraints

Amorim, Vicente José Peixoto de 07 August 2010 (has links)
Orientador: Ricardo de Oliveira Anido / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Computação / Made available in DSpace on 2018-08-16T15:08:23Z (GMT). No. of bitstreams: 1 Amorim_VicenteJosePeixotode_M.pdf: 4964887 bytes, checksum: bfab031069f938f7f502f1bc4f0d5d13 (MD5) Previous issue date: 2010 / Resumo: O estudo crítico apresentado discute o problema de ordenação de mensagens, típico da área de sistemas distribuídos, contextualizado em um ambiente de comunicação Bluetooth. Por ainda serem poucos os trabalhos com tal foco na bibliografia atual, este provê uma visão geral do comportamento de uma classe específica de protocolos distribuídos, quando executados no ambiente citado. Partindo desse contexto, o trabalho utiliza uma análise comparativa de alguns dos diversos algoritmos existentes, como forma de se obter informações sobre determinadas variáveis, e se caracterizar o melhor a ser utilizado em um ambiente de comunicação sem-fio com restrições de tempo real (real time). Ao se demonstrar a viabilidade de utilização deste(s) dentro de um ambiente de comunicação Bluetooth (com características real time), automaticamente surgem novas oportunidades de aplicações, principalmente para redes móveis onde a topologia predominante é ad- hoc, ou ainda, qualquer outro tipo de aplicação em que seja necessário se garantir a entrega em ordem das informações compartilhadas dentro de um limite de tempo. Como resultado desta análise, propõe-se um protocolo para o problema de ordenação total de mensagens aplicado a redes Bluetooth, onde se garante que, no ambiente de comunicação, todas as informações trocadas pelos nós (sites) serão enviadas e recebidas na mesma ordem. / Abstract: The presented work discuss the messages ordering problem, a common subject associated to distributed systems area which was here contextualized against Bluetooth network environment. The main target of this work is focused on distributed algorithms not so commonly considered until now, specially when they are applied to this related environment. As a way to obtain enough information about some systems variables and behavior, a comparative analysis was made between the already proposed protocols and algorithms. It generates a large set of information that makes possible to identify the better approach to be aplied at real time environments. Once the protocol viability is demonstrated, a large set of new applications can arise, specifically to this case: mobile applications using Bluetooth networks. This is mainly due to the mobile ad-hoc network topology which allows the use of distributed applications. However, it can also bring another class of problems as message ordering, which must ensure that all network shared data will keep a local and global sending order. / Mestrado / Computação Distribuída / Mestre em Ciência da Computação
422

Inomhuspositionering och platsmedvetenhet : Automatiserad styrning av elektronik baserat på användares position

Lindström, Hugo January 2016 (has links)
By scanning the area for Bluetooth-signals, users can find and subscribe to Bluetooth-advertisements and thus estimate its current position. The position is used to identify what actions could be executed in the premises. This report explains the underlying technology and proposes a system architecture for a Android application that together with user authentication, WebSockets and API's could control doors, ventilation, lighting and other indoor devices wirelessly. This project was carried out in collaboration with ÅF Technology AB, Embedded Systems, where the goal was to conduct a pre-study and propose how to add contextual awareness to mobile devices, implement and evaluate a working system. / Genom att läsa av området på Bluetooth-signaler kan användare hitta och prenumerera på Bluetooth-annonseringar och därmed skatta sin position. Positionen används för att identifiera vilka handlingar som trådlöst kan uträttas i lokalen. Denna rapport förklarar bakomliggande teknik och föreslår systemarkitektur för en Android applikation som tillsammans med Autentisering, WebSockets och tillhörande API kan styra närliggande elektriska enheter, så som ventilation, dörrar och kaffemaskiner. Detta projekt utfördes tillsammans med ÅF Technology AB, Embedded Systems där målet är att genomföra en förstudie där möjliga teknologier, arkitektur, API:er samt hårdvara utvärderas som ligger till grund för implementering och utvärdering av ett fungerande system.
423

Tidsuppfattning för dövblinda / Time Understanding for Deafblind People

Remes, Johan January 2010 (has links)
This project is about the development of a application to aid deafblind people with time understanding. The application is written in C# language and have multiple functions to alarm the user. The application can alarm deafblind persons through a combination of sounds, pictures and vibrations. This makes the application very flexible and can be used by many different groups like deaf, blind and older people. This application have been evaluated by staff from Mo Gård resurscenter. / Det här arbetet handlar om att utveckla ett hjälpmedel för personer som lider av dövblindhet med en kognitiv nedsättning. Målet med projektet är att utveckla en applikation som ska hjälpa dessa personer med sin tidsuppfattning. Applikationen är skrivet i programmeringsspråket C# och har flera olika funktioner som ska ge användaren en tydligare uppfattning om tiden. Applikationens fördel är att den kan kombinera information via olika kommunikationsvägarna; visuellt, auditivt och taktilt. Det gör att applikationen är mycket flexibelt och att många olika målgrupper till exempel döva, blinda och äldre kan använda sig utav applikationen. Applikationen har utvärderats av Mo Gårds hemmets personal och har resulterat i positiv kritik.
424

Cross-platform Mobile Development and Internet of Things : Developing a cross-platform mobile application using web technologies to interact with smart things

Anton, Andersson, Runbert, Johan January 2015 (has links)
Today more and more objects in our daily lives are getting connected to the Internet. This phenomenon is called the Internet of Things and is a way for physical things such as cars, buildings or even bus stations to get access and communicate with other objects using the Internet. The problem is that for every Internet of Things device, an application is often needed in order to communicate with these devices. Developing mobile applications in a separate programming language for each operating system can be an expensive and time consuming task. In this thesis, we implement and evaluate a cross-platform mobile solution for users to interact with smart things using the advantages of web technologies. To compare previous findings in this area, two literature reviews has been performed to find out which is the state of the art on cross-platform mobile development frameworks and smart-things technologies used for interacting with physical objects. The result is a mobile application developed using PhoneGap and jQuery Mobile that interacts with iBeacons, where students inside a university building can get directions and schedules for different rooms. The application received good results from a couple of usability studies, and performed well when measuring its performance. The outcome shows that web technologies that exist today are a viable solution to native mobile applications in terms of interacting with smart things such as tagging technologies.
425

Inomhuspositioneringssystem : Personlig navigation inomhus via mobiltelefon / Indoor Positioning System : Personal indoor navigation via mobile phone

Johansson, Charlie, Frid, Martin January 2015 (has links)
GPS används idag för personlig navigering men dessvärre är GPS beroende av fri sikt och presterar sämre i en inomhusmiljö. Ett IPS, inomhuspositioneringssystem, skulle komplet-tera GPS:ens funktion samt öppna dörrar för nya användningsområden inom positionering. I detta examensarbete studerades metoder och tekniker för att möjliggöra ett IPS för en mo-bil enhet. Där teknikerna och metoderna verifieras för att kunna implementeras i en mobil-telefon.En prototyp för ett IPS framställdes för att utreda möjligheterna att navigera i en inomhus-miljö. En radiofingeravtrycksmetod baserat på RSSI-mätningar från Bluetooth-enheter im-plementerades och integrerades med en dödräkningsmetod som använder en IMU för att positionera användaren. Utefter tester och simuleringar utförts presenteras resultatet i form av figurer och tabeller. Med hjälp av prototypen går det att navigera med ett medelfel på 0,26m. Resultatet visar också på att en integrering av två metoder är att föredra då de kan komplettera varandras svagheter. / The GPS is used today for personal navigation, however GPS performs less well in an in-door environment due to the dependency of line of sight. The IPS, Indoor Positioning Sys-tem, will complement the function of the GPS and open doors for new applications. In this thesis studies of methods and techniques are made to enable IPS for a portable device. These techniques and methods are verified that they could be implemented in a smartphone.A prototype was designed to examine the possibility to navigate in an indoor environment. The prototype was built on a RSSI-based radio fingerprinting method over Bluetooth. This method was integrated with a dead reckoning system using an IMU to follow the motions of the user. Tests and simulations are performed along with the results presented in tables and figures. The result shows that it is possible to navigate using the prototype with a mean error of 0.26m. Results are also showing that two methods are to prefer, as they will com-plement each other’s weaknesses.
426

Trådlös strömning av en ljudsignal till multipla mottagare / Wireless streaming of an audio signal to multiple receivers

Sandberg, Johnny January 2013 (has links)
I detta examensarbete har det undersökts vilken teknik för trådlös kommunikation som passar bäst att användas då en ljudsignal ska strömmas trådlöst till multipla mottagare. De tekniker som jämfördes var Wi-Fi och Bluetooth. Andra tekniker för trådlös kommunikation, ZigBee, ANT+ och NFC, valdes bort för att deras maximala datahastighet eller räckvidd inte var tillräcklig. 3G och 4G valdes bort för att det krävs en licens för att få använda dessa. Som mottagare skulle i första hand Android- och iOS-mobiltelefoner användas. Dessutom har det undersökts vilka komponenter som behövs för att tillverka en prototyp som ska kunna strömma en ljudsignal trådlöst till multipla smartphones. Slutligen gjordes ett kopplingsschema för denna prototyp. Wi-Fi med WLAN-infrastruktur ansågs vara bäst lämpad för denna applikation. Prototypen som skulle strömma ljudsignalen behövde därför kunna fungera som en Wi-Fi-accesspunkt. Wi-Fi-chipet AR9271 från Qualcomm Atheros valdes att användas som Wi-Fi-sändare för att den har open-source firmware och var lättare att få tag på jämfört med andra liknande Wi-Fi-chip. För att kunna använda Wi-Fi-chipets Linuxbaserade open-source firmware valdes SAM9M10 MCU från Atmel att användas som kontrollenhet då denna kan användas med Linux Embedded. För att digitalisera den analoga ljudsignalen valdes VS1063 Mp3-kodare från VLSI Solution. / This thesis has examined which wireless technology that is best suited for use when an audio signal are to be streamed wirelessly to multiple recipients. The technologies that where compared was Wi-Fi and Bluetooth. Other wireless communication technologies, ZigBee, ANT+ and NFC, were excluded because their maximum data rate or range wasn’t sufficient enough. Since it’s required a license to be allowed to use 3G and 4G, these were excluded as well.  As receivers, primarily Android and iOS phones would be used. Furthermore, it has been examined which components that are required for manufacturing a prototype that will be able to stream an audio signal wireless to multiple smartphone’s. Lastly, a circuit diagram for this prototype has been made. Wi-Fi WLAN infrastructure was considered to be best suited for this application. The prototype that would stream an audio signal therefore needed to function as a Wi-Fi access point. AR9271, a Wi-Fi chip from Qualcomm Atheros, was selected to be used as Wi-Fi transmitter because it has an open-source firmware and were easier to come by compared to other similar Wi-Fi chip. To be able to use the Linux-based open-source firmware of the Wi-Fi chip, SAM9M10 MCU from Atmel was selected as control unit since it can be used with Linux Embedded. In order to digitize the analog audio signal, VS1063 MP3 encoder from VLSI Solution was selected.
427

An integrated sensor system for early fall detection

Bandi, Ajay Kumar 05 1900 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Physical activity monitoring using wearable sensors give valuable information about patient's neuro activities. Fall among ages of 60 and older in US is a leading cause for injury-related health issues and present serious concern in the public health care sector. If the emergency treatments are not on time, these injuries may result in disability, paralysis, or even death. In this work, we present an approach that early detect fall occurrences. Low power capacitive accelerometers incorporated with microcontroller processing units were utilized to early detect accurate information about fall events. Decision tree algorithms were implemented to set thresholds for data acquired from accelerometers. Data is then verified against their thresholds and the data acquisition decision unit makes the decision to save patients from fall occurrences. Daily activities are logged on an onboard memory chip with Bluetooth option to transfer the data wirelessly to mobile devices. In this work, a system prototype based on neurosignal activities was built and tested against seven different daily human activities for the sake of differentiating between fall and non-fall detection. The developed system features low power, high speed, and high reliability. Eventually, this study will lead to wearable fall detection system that serves important need within the health care sector. In this work Inter-Integrated Circuit (I2C) protocol is used to communicate between the accelerometers and the embedded control system. The data transfer from the Microcontroller unit to the mobile device or laptop is done using Bluetooth technology.
428

Message Classification Based Continuous Data Transmission for an E-health Embedded System

Sun, Jiuwu January 2019 (has links)
This thesis aims to develop an e-health embedded system with a real-time operating system (RTOS), which allows users to monitor their body condition, including heart rate and breath, through Bluetooth Low Energy (BLE). Meanwhile, the device is also able to provide guidance for breathing by simulating breathing according to given parameters. In practice, the system samples the heart rate every two milliseconds. To ensure reliability and validity, results are expected to be sent in realtime. However, numerous data cannot be transmitted directly without being processed. Otherwise, the system will crash, and hard faults will occur. A general idea to solve this problem is to classify messages into two categories based on the priority. One is urgent, and the other is unimportant. Two solutions are proposed, one using a unidirectional linked list, and the second using queues. Based on an ARM micro-controller, the e-health embedded system is designed and implemented successfully. The evaluation results show that the solution using a linked list is suitable for the system, while the solution using queues is unable to solve the problem. With the help of the message classification, the urgent messages can be timely transmitted with continuous data. / Avhandlingen syftar till att utveckla ett e-hälso-inbyggt system med ett realtidsoperativsystem (RTOS), som gör det möjligt för användare att övervaka sitt kroppstillstånd, inklusive hjärtfrekvens och andetag, genom Bluetooth Low Energy (BLE). Samtidigt kan enheten också ge vägledning för andning genom att simulera andning enligt givna parametrar. I praktiken samplar systemet hjärtfrekvensen varannan millisekund. För att säkerställa tillförlitlighet och giltighet bör resultaten skickas i realtid. Annars kraschar systemet och allvarliga fel uppstår. En allmän idé för att lösa detta problem är att klassificera meddelanden i två kategorier baserade på prioritering, en är brådskande och den andra är obetydlig. Två lösningar föreslås, en med hjälp av riktad länkad lista och en annan implementerad med hjälp av köer. Resultatmässigt, baserat på en ARM-mikrokontroller, är det inbyggda e-hälsosystemet framgångsrikt designat och konfigurerat. Lösningen med en länkad lista är lämplig för systemet, medan lösningen som implementeras med köer fortfarande inte kan lösa problemet. Med hjälp av meddelandeklassificeringen är de brådskande meddelandena inte ens försenade med kontinuerlig data.
429

[en] OPPORTUNISTIC ROUTING TOWARDS MOBILE SINK NODES IN BLUETOOTH MESH NETWORKS / [pt] ROTEAMENTO OPORTUNÍSTICO EM DIREÇÃO A NÓS SINK MÓVEIS EM REDES BLUETOOTH MESH

MARCELO PAULON JUCA VASCONCELOS 26 April 2021 (has links)
[pt] Este trabalho avalia a coleta esporádica de dados em uma rede sem fio Bluetooth Mesh, usando o simulador OMNET (mais mais) INET. O coletor de dados é um nó sink em movimento, que poderia ser um smartphone ou outro dispositivo portátil, carregado por um pedestre, ciclista, animal, ou um drone. O nó sink poderia se conectar a uma rede mesh em áreas de difícil acesso onde não há acesso a internet, e coletar dados de sensores. Após implementar extensões ao Bluetooth Mesh, funcionalidades de nós Low Power e Friends no OMNET (mais mais), conseguimos propor e avaliar algoritmos para roteamento adaptativo, e com foco em mobilidade, de dados de sensores em direção ao nó sink. Uma variação de um dos algoritmos de roteamento propostos alcançou um aumento de 173,54 por cento na quantidade de dados únicos entregues ao nó sink em comparação ao algoritmo de roteamento padrão do Bluetooth Mesh. Neste caso, houve um aumento de apenas 4,63 por cento no consumo de energia para o mesmo cenário. Além disso, a taxa de entrega aumentou em 111.82 por cento. / [en] This work evaluates sporadic data collection on a Bluetooth Mesh network, using the OMNET (plus plus) INET simulator. The data collector is a roaming sink node, which could be a smartphone or other portable device, carried by a pedestrian, a biker, an animal, or a drone. The sink node could connect to a mesh network in hard-to-reach areas that do not have internet access and collect sensor data. After implementing Bluetooth Mesh relay extensions, Low Power, and Friend features in OMNET (plus plus), we were able to propose and evaluate algorithms for mobility-aware, adaptive, routing of sensor data towards the sink node. One variation of a proposed routing algorithm achieved a 173.54 percent increase in unique data delivered to the sink node compared to Bluetooth Mesh s default routing algorithm. In that case, there was only a 4.63 percent increase in energy consumption for the same scenario. Also, the delivery rate increased by 111.82 percent.
430

Populating a Database to be used with an Indoor Positioning System / Populera en databas som ska användas med ett inomhuspositioneringssystem

Halvarsson, Maria, Qin, Jinglan January 2022 (has links)
Indoor Positioning System (IPS) are becoming more common in many areas such as retail, warehouses, smart facilities, and manufacturing.In recent years, Bluetooth Low Energy (BLE)-based IPS has become increasingly popular due to its low cost and low energy consumption. One of the more recent updates, Bluetooth 5.1, provides the ability to compute the location using Angle of Arrival (AoA) or Angle of Departure (AoD). These new features have allowed for better positioning accuracies, where AoA-based positioning has shown sub-meter accuracy. An application area for BLE-based IPS is retail stores where the technology can benefit both the store and its customers. This thesis investigates how to populate a database to be used with an IPS in a real-life store. The assumption is that customers will have BLE equipped devices and run an application that will send the properly formatted BLE advertisements, such that an BLE IPS can locate the user in the store. Additionally, we assume that the application can use the device's e-compass or other means to determine in which direction the user's device is oriented. Based on the position and orientation of the user, the software is assumed to access a database to know what item(s) are near the customer. However, the question remains of how did this data get into the database? This degree project explores this in detail and assesses the amount of time and effort needed to populate this database and the amount of time and effort needed to keep this database up to date. This project followed an iterative Design Science Research (DSR) methodology where the artifact is the database. A relational database was used as they are widely used and joins can easily be performed and it is easy to modify existing tables. The application was developed in Spring Boot and React. Amazon Web Services (AWS) was used to host and provide the necessary services for the database and application. The result showed that the estimated time needed to populate the database in a supermarket with a sales area of 5300 m2, 36623 products, and 220 containers is 106.64 hours and 107.13 hours in the worst case assuming a walking speed of 1.4 m s-1. Updating a product would take 10.34 s and 10.37 s if the time it takes for a staff member to walk to the place where the product is located is excluded. / Inomhuspositioneringssystem (IPS) har blivit allt vanligare inom många områden. De senaste åren har Bluetooth Low Energy (BLE)-baserad inomhuspositionering blivit mer populärt på grund av egenskaper som låg kostnad och låg energikonsumption. En av de senaste versionerna; Bluetooth 5.1 kan beräkna positionen med hjälp av ankomstvinkeln (eng. Angle of Arrival (AoA)) och utgångsvinkeln (eng. Angle of Departure (AoD)). Angle of Arrival (AoA)-baserad positionering kan uppnå en noggrannhet under 1 m. Ett Bluetooth Low Energy (BLE)-baserat IPS kan tillämpas i butiker där det kan gynna både butikens medarbetare och dess kunder. Detta examensarbete kommer att undersöka hur en databas som ska användas med ett IPS i en butik kan populeras. Antagandet i detta projekt är att kunderna kommer ha BLE utrustade enheter som kör ett program som tillåter att användaren kan lokalisera sig i butiken. Dessutom antar vi att applikationen kan använda enhetens e-kompass eller annan hårdvara för att kunna avgöra i vilken riktning användarens enhet är orienterad. Baserat på användarens position och riktning, antas det att mjukvaran kan komma åt databasen och veta vilka produkter som ligger i närheten av kunden. Dock kvarstår frågan: Hur sparades denna data i databasen? Det här examensarbetet kommer alltså att undersöka hur en databas i en butik kan vara uppbyggd om vi utgår från antagandet att BLE är tillämpat i butiken. Vi kommer även bedöma hur mycket tid som krävs för att populera en databas och hålla denna databas uppdaterad. Ett iterativ arbetsätt tillämpades i examensarbetet. I projektet användes en relationsdatabas eftersom det är enkelt att utföra join-operationer och uppdatera tabbeller i databasen. Applikationen som skapades tillhandahåller funktioner för att spara, uppdatera, radera och söka produkter i databasen. Frontend var kodad i React och backend var kodad i Spring Boot. Amazon Web Services (AWS) molntjänser och deras verktyg användes för att köra applikationen och databasen. Resultatet visade att populera en databas med produkter i en mataffär med en säljyta på 5300 m2, 36623 produkter, och 220 behållare (hyllor, kylskåp, etc.) tog 106.64 timmar i bästa fall och 107.13 timmar i värsta fall om vi antar en gångfart i 1.4 m s-1.

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