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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.
61

Proposta de técnica de localização interna para dispositivos móveis utilizando redes locais sem fio

BARROS, Antônio Carlos Genn de Assunção 12 February 2016 (has links)
Submitted by Rafael Santana (rafael.silvasantana@ufpe.br) on 2017-08-30T17:07:46Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Antonio_Thesis.pdf: 3530353 bytes, checksum: 0ba09bccbe8eb163cd5b4646977ba882 (MD5) / Made available in DSpace on 2017-08-30T17:07:46Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Antonio_Thesis.pdf: 3530353 bytes, checksum: 0ba09bccbe8eb163cd5b4646977ba882 (MD5) Previous issue date: 2016-02-12 / Atualmente as redes locais sem fio (WLANs) em ambientes internos estão presentes na maioria dos prédios públicos. Estas redes, além da sua função principal, podem ser utilizadas para localização de pessoas e objetos, salientando que nestes ambientes não é adequada a utilização do sinal de GPS para esta finalidade. Diversos estudos e pesquisas nesta área têm sido realizados. Serviços baseados na localização interna possuem inúmeras aplicações nas áreas de segurança, médica, monitoramento, navegação, auxílio a deficientes, gerenciamento de pessoas, entre outras e hoje já movimentam um mercado de US$1 Bilhão. Com a proliferação da Internet das Coisas (IoT), estes valores serão ainda maiores. Os sistemas de localização interna utilizam tecnologias como Ultrassom, Infravermelho, RFID, Bluetooth e WLAN, variando conforme a precisão, exatidão, custo, velocidade de resposta, infraestrutura e aplicação. O presente trabalho propõe uma técnica de localização interna que utiliza a intensidade do sinal recebido (RSS — Received Signal Strength) das redes WLAN presentes como medida para localização. Na técnica proposta, é feito inicialmente um mapeamento das intensidades dos sinais da WLANs existentes. Estes valores são classificados através de um Algoritmo de Agrupamento (clustering) e, posteriormente, são aplicados, a cada agrupamento, algoritmos de regressão para o cálculo da localização. Associada a estas técnicas são aplicados filtros visando minimizar as variações do sinal medido decorrentes de interferências do meio. Esta técnica não necessita de grandes esforços de calibração nem alterações na estrutura existente, apenas utilizando a rede WLAN já instalada, obtendo assim uma precisão compatível com aplicações de localização de pessoas e objetos e auxílio em navegação em ambientes internos. Na implementação e testes da técnica proposta, foi empregado o processador Edison da Intel para a coleta das intensidades dos sinais — RSS e como plataforma de servidor foi utilizada a estrutura de nuvem da Microsoft através do Azure-Studio Machine Learning, apropriada para a análise e predição de dados da técnica utilizada. As medições para composição dos conjuntos de testes e validação foram realizadas no prédio do Centro de Informática da UFPE, demonstrando que apesar do baixo esforço de calibração, sem alteração da estrutura existente, atendem aos requisitos necessários. Resultados preliminares mostram que 60% das amostras estavam com erro inferior a 5 metros. / Currently, wireless local networks (WLANs) in internal environments are present in most of the public buildings. These networks, in addition to their main function, can be used to locate people and objects, stressing that in these environments it is not adequate the use of the GPS signal to this goal. Several studies and researches in this area have been made. Services based in internal location have many applications in security, health, monitoring, navigation, disabled assistance, and people management, among other areas. Nowadays, they already move a US$ 1 billion market. With the proliferation of the Internet of Things (IoT), these values will increase even further. Internal location systems use technologies such as Ultrasound, Infra-red, RFID, Bluetooth, and WLAN, varying according to the required precision, accuracy, cost, response speed, infrastructure, and application. The following work proposes an internal location technique that uses the received signal strength (RSS) from existing WLAN networks as a location measurement. In the proposed technique, is initially made a mapping of the existing WLANs signals intensities, these values are classified through a Clustering Algorithm and, after that, regression algorithms are applied to each group towards a location classification. Associated to these techniques, filters are applied aiming to minimize the measured signal variations due to the environment interferences. This technique doesn’t require big calibration efforts, nor changes in the existing structure, just uses the already installed WLAN network, obtaining a precision compatible to the one required for people and objects location and assistence in internal environments navigation. In the proposed technique’s implementation and tests, it was used Intel’s Edison processor to collect RSS signal’s intensities. As a server platform, it was used Microsoft’s cloud structure through the Azure-Studio Machine Learning, appropriate for the used technique’s analysis and data prediction. The main set of tests and validation was accomplished in the UFPE Informatics Center building, showing that despite low calibration effort, without changing the existing structure, it complies with the necessary requirements. Preliminary results show that 60% of the samples had errors under 5 meters.
62

Indoor Positioning Using WLAN / Inomhuspositionering med WLAN

Andersson, Pierre, Norlander, Arvid January 2012 (has links)
This report evaluates various methods that can be used to position a smartphone running the Android platform, without the use of any special hardware or infrastructure and in conditions where GPS is unavailable or unreliable; such as indoors. Furthermore, it covers the implementation of such a system with the use of a deterministic fingerprinting method that is reasonably device independent, a method which involves measuring a series of reference points, called fingerprints, in an area and using those to locate the user. The project was carried on behalf of Sigma, a Swedish software consulting company. / Denna rapport evaluerar olika metoder för att bestämma positionen av en smartphone som använder sig av Android-plattformen. Metoden skall inte använda sig av någon speciell hårdvara eller infrastruktur samt kunna hantera förhållanden där GPS är otillgängligt eller opålitligt, som till exempel inomhus. Den beskriver också implementation av ett sådant system som använder sig av en deterministisk fingerprinting-metod som någorlunda väl kan hantera enheter av olika modeller, en metod som innebär att man mäter upp en mängd med referenspunkter, kallade fingerprints, och använder dessa för att placera användaren. Projektet utfördes på uppdrag av Sigma, ett svenskt mjukvarukonsultbolag.
63

RSS – The future of internal communication?

Andersson, Ola, Larsson, Niclas January 2005 (has links)
RSS is a format for easy information sharing between computers. A RSS-file, also known as a feed or a channel, consist of a list of items. The items are structured with XML-tags and have to be processed in some way before it can be read. RSS¬readers, web-browsers with RSS support and e-mail-clients with RSS support can be used to display the feed. This thesis is focused to investigate if RSS can be used within an enterprise for internal communication. We look at different computer based communication tools that are available today and compare them with RSS. All the different tools has there advantages as well as disadvantages, we have tried to find out if there is room for one more information channel within an enterprise. Our study shows that RSS is not suitable as a stand alone solution for internal combination. RSS main strengths lies in mass information that has to be pushed out in one direction.
64

Marketing through web 2.0 : How likes, shares and comments can effect organizations

Lan, Tingsong, Klawitter Petersson, Jonathan January 2015 (has links)
With the statistical numbers that shows how companies year after year moves more and more money from traditional marketing budgets to inbound marketing budgets as a result of a past success within the field of inbound marketing, the purpose of this study is to examine what can be derive from their use of the Web 2.0 technology as a marketing tool. The target-group for this study is mainly organizations that are interested in the use of Web 2.0 technologies and an academic audience as students and researchers.This study have used it selves of a Hermeneutics scientific approach and an abductive approach towards the relationship between theory and research. Semi-structured interviews have been conducted as the method for collection of data for the empirical study. The selections of the respondents to the empirical study have been selected through different criterias were the organizations use and frequency of use of Web 2.0 technology were a primary criteria.The conclusion of this study shows that there are some major advantages that can be derived from the use of Web 2.0 technology in organizations marketing communication, the interactions with consumer and the use of the interaction to improve organizations processes. The drawbacks that were discovered are mainly the organizational changes that an organization has to go through when implementing Web 2.0 technologies in their marketing communication and the risk of negative viral spread. The future opportunity for using Web 2.0 in marketing communication is that it can lead to new creative ways to interact with the customers.
65

Využítí nástrojů web 2.0 při výuce / Use of Web 2.0 technologies in education

Doubravová, Lucie January 2010 (has links)
The thesis Use of Web 2.0 technologies in education introduces the concept of Web 2.0 and its basic characteristics. The first chapter is based on the explanation of major tools and technologies labelled as Web 2.0. The second chapter deals with specific services which have already found its place in education process. The same chapter evaluates the ways of dealing with their appropriate use, particularly in higher education. This chapter contains also the examples of successful use in education. The thesis is mainly concerned about using Web 2.0 tools in the environment of Czech schools. As Web 2.0 services are not new, I asked students and teachers at the University of Economics in Prague and asked what experience they have with such instruments in their personal life, so in context of education. The third chapter is entirely devoted to survey the use of Web 2.0 tools in the practice of The University of Economics in Prague. Content of the final chapter is a reflection of what direction the web will evolve in the coming years. It also evaluates social issues associated with the turbulent development of the Internet and Web 2.0.
66

Localization of eNodeBs with a Large Set of Measurements from Train Routers / Lokalisering av eNodeB:er med en stor mängd mätningar från tåg routrar

Sundberg, Simon January 2019 (has links)
This master thesis investigates the possibility of locating LTE base stations, known as eNodeBs, using signal measurements collected by routers on trains. Four existing algorithms for transmitter localization are adopted: the centroid, strongest signal, Monte Carlo path loss simulation and power difference of arrival (PDoA) methods. An improved version of Monte Carlo path loss simulation called logloss fitting is proposed. Furthermore, a novel localization method called sector fitting is presented, which operates solely on the cell identity and geographical distribution of the measurements. The methods are evaluated for a set of manually located eNodeBs, and the results are compared to other external systems that can be used to locate eNodeBs. It is found that the novel sector fitting algorithm is able to considerably improve the accuracy of the logloss fitting and PDoA methods, but weighted centroid is overall the most accurate of the considered methods, providing a median error of approximately 1 km. The Google Geolocation API and Mozilla Location Service still provides estimates that are generally closer to the true location than any of the considered methods. However, for a subset of eNodeBs where measurements from all sectors are available, the novel sector fitting algorithm combined with logloss fitting outperforms the external systems. Therefore, a hybrid approach is suggested, where sector fitting combined with logloss fitting or weighted centroid is used to locate eNodeBs that have measurements from all sectors, while Google Geolocation API or Mozilla Location Service is used to locate the remaining eNodeBs. It is concluded that while the localization performance for those eNodeBs that have measurements from all sectors is relatively good, further improvements to the overall results can likely be obtained in future work by considering environmental factors, the angular losses introduced by directional antennas, and the effects of downlink power control.
67

Lokalizace počítačových zařízení ve Wifi sítích / Device Location in Wireless Network

Szabó, Peter January 2015 (has links)
This thesis deals with the issue of locating devices in wireless networks. It takes existing solutions as example and extends them using additional approaches. This thesis designs and describes the implementation of a prototype of a new proprietary indoor localization system used for locating devices within a WiFi network. In the final part of the thesis the testing of this system is described and its results are analysed and compared with another localization systems based on similar technologies.
68

Eliminating Redundant and Less-informative RSS News Articles Based on Word Similarity and A Fuzzy Equivalence Relation

Garcia, Ian 10 January 2007 (has links) (PDF)
The Internet has marked this era as the information age. There is no precedent in the amazing amount of information, especially network news, that can be accessed by Internet users these days. As a result, the problem of seeking information in online news articles is not the lack of them but being overwhelmed by them. This brings huge challenges regarding processing of online news feeds, i.e., how to determine which news article is important, how to determine the quality of each news article, and how to filter irrelevant and redundant information. In this thesis, we propose a method for filtering redundant and less-informative RSS news articles that solves the problem of excessive number of news feeds observed in RSS news aggregators. Our filtering approach measures similarity among RSS news entries by using the Fuzzy-Set Information Retrieval model and a fuzzy equivalent relation for computing word/sentence similarity to detect redundant and less-informative news articles.
69

Manager Tools Podcast: A Study of Podcasting's Effectiveness with Profit Potential

Beal, Quincy Frodesen 04 December 2008 (has links) (PDF)
This thesis seeks to understand further the effectiveness and profit potential of podcasting. The study combines the theories of uses and gratifications and subjective theory of value to create a model for podcasting's value. The model is put to the test using the Manager Tools podcast as the subject. Data suggest the three main drivers behind perceived podcast effectiveness are pleasure, habit, and information gathering. Relaxation proved to have a negative influence on perceived effectiveness. The audience's willingness to pay was determined by perceived effectiveness, scarcity, and habit. Though not a generalizable study, the conclusion discusses the findings' implications on the podcasting community.
70

Gaussian process-assisted frontier exploration and indoor radio source localization for mobile robots

Rasines Suárez, Javier January 2018 (has links)
Autonomous localization of a radio source is addressed, in the context of autonomous charging for drones in indoor environments. A radio beacon will be the only input used by the robot to navigate to an unknown charging station, at an unknown area. Previous proposed algorithms used frontier-based exploration and the measured RSS to compute the direction to the source. The use of Gaussian processes is studied to model the Radio Signal Strength (RSS) distribution and generate an estimation of the gradient. This gradient was also incorporated into a frontier exploration algorithm and was compared with the proposed algorithm. It was found that the usefulness of the Gaussian process model depended on the distribution of the RSS samples. If the robot had no prior samples of the RSS, then the gradient-assisted solution performed better. Instead, if the robot had some prior knowledge of the RSS distribution, then the Gaussian process model yields a better performance. / Autonom utforskning av en radiokälla behandlas, i samband med autonom laddning för drönare i inomhusmiljöer. En radiofyr kommer att vara den enda information som roboten använder för att navigera till en laddningsstation i ett okänt område. Tidigare föreslagna algoritmer använde gränsbaserad undersökning och den uppmätta RSS:en för att beräkna källans riktning. Användning av Gaussiska processer studeras för att modellera RSS-distributionen och generera en uppskattning av gradienten. Denna gradient införlivades också i en gränsutforskningsalgoritm och jämfördes med den föreslagna algoritmen. Det visade sig att användningen av den gaussiska processmodellen berodde på distributionen av RSS-proverna. Om roboten inte hade några tidigare prover av RSS, presterade den gradientassisterade lösningen bättre. Istället, om roboten hade några prover av RSS (till exempel om den utfört en annan uppgift på någon region i kartan), ger Gaussiska processmodellen bättre prestanda.

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