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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.
181

Desenvolvimento de um protótipo veicular destinado às atividades de campo

Vist, Helio Larri January 2007 (has links)
O Sistema de Posicionamento Global (GPS) permite uma grande variedade de aplicações civis e militares. Dentre as várias aplicações, uma de especial interesse é a navegação, que tem crescido muito nos últimos anos devido a fatores como menor custo, e fácil utilização desta tecnologia. Num sistema de navegação terrestre, assim como na navegação marítima, fluvial e aérea, um mapa digitalizado, ou imagem de satélite disponível da região de interesse é exibida na tela do computador de bordo e a posição do veículo é apresentada em "tempo real" a partir da posição fornecida por receptores GPS. Além disso, a comunicação disponível nos dias de hoje permite uma maior integração entre o veículo e o escritório. Finalmente, o Google Earth permite que se tenha acesso a uma grande quantidade de informações necessárias ao desenvolvimento de inúmeros trabalhos, permitindo inclusive a inserção de fotos e imagens para registro dos acontecimentos. O potencial deste tipo de sistema só foi possível a partir de maio de 2000, com a eliminação da SA (Selective Availability).Com isso, o posicionamento absoluto realizado por receptores de navegação (menos precisos do que os receptores geodésicos) foi aprimorado, podendo conseguir precisões da ordem de 10m, o que aumenta a qualidade de aplicações como a navegação terrestre. A proposta desta dissertação é descrever o desenvolvimento de um protótipo veicular para aplicações de campo em Geociências, onde foi incluída a navegação em tempo real, o uso da internet para a comunicação pessoal e interface de acesso ao Google Earth. O protótipo desenvolvido permite a extensão de parte da infra-estrutura de um laboratório para apoio das atividades de campo. / In our days the Global Positioning Systems (GPS) is a technology with a great variety of military and civilian applicability. Among this uses, navigation is one activity that is largely increasing in reason to lowering equipment prices and introduced facilities as easy to use technology. In practice, a system structured to navigate in terrestrial, maritime, fluvial or aerial way is formed by a GPS connected to an onboard computer and video equipped with appropriate software that process in a instantaneous mode (real time) all the information necessary to show on screen the geographical position of the vehicle. In parallel, new advances in network communication open the possibility to integrate completely the vehicle in movement with the staff in the office. Also, the Geoogle Earth™ and World Wide Web increase the facilities to view online the terrain and open the possibility to user interact directly with routines that insert local photo and images. Navigate with accuracy using a single-receiver GPS linked to a computer was only possibly after May of 2000, when the SA (Selective Availability) was excluded from GPS signal. Consequently, absolute positioning with one band handled GPS (low accuracy when compared to geodetic two bands GPS) was tested and the results show the availability to locate points in the Earth surface with an uncertainty degree not above than 10 meters (in terms of planimmetric coordinates). This performance increases the data quality and the ability of single-receiver GPS to be used to navigation purposes. In this work, it is assembled and tested a navigation system prototype installed in a vehicle with the objective to optimize field survey and adapted to some geosciences necessities, including the possibility to navigate in real time integrated with Internet facilities to personal communication and with an interface to access the Google Earth™. The configuration of the navigation system prototype elaborated in this project permit to extend to the field some facilities only accessible in a laboratory environment and consequently the results obtained with the system increased the performance of all the field work stages.
182

Cascading Web Services in Mobile Environments : Bridging Wireless and Wired Networks for Data Transactions

Kajtazi, Miranda, Vogel, Bahtijar January 2007 (has links)
Cascading Web Services represent a collection of services offered in a system consisting of multiple devices and multiple interacting platform independent networks. ‘Cascading’ enables Web Services to exploit access in diverse environments without manual intervention. The aim of this thesis is to investigate how Mobile Web Services interact with multiple other Web Services by allowing the generated content to cascade. These services are demonstrated as a technical design solution, in a number of cases within the field of Learning technologies. Communication among devices is preceded using request-response commands by cascading these commands between different Web Services that are self-contained and independent on their context or state. The system signifies a typical Service Oriented Architecture (SOA) based on a distributed system. Cascading Web Services involve multiple transport networks including Bluetooth Technology, GPRS, Wi-Fi, and Wired Networks. Whereas the protocol of this communication is to bridge Wired and Wireless networks for data transactions, specifically from a Bluetooth location-based network. A number of particular cases will be illustrated in the context of ‘educational outdoor activities’, to demonstrate how the system solution works involving users.
183

Desenvolvimento de um protótipo veicular destinado às atividades de campo

Vist, Helio Larri January 2007 (has links)
O Sistema de Posicionamento Global (GPS) permite uma grande variedade de aplicações civis e militares. Dentre as várias aplicações, uma de especial interesse é a navegação, que tem crescido muito nos últimos anos devido a fatores como menor custo, e fácil utilização desta tecnologia. Num sistema de navegação terrestre, assim como na navegação marítima, fluvial e aérea, um mapa digitalizado, ou imagem de satélite disponível da região de interesse é exibida na tela do computador de bordo e a posição do veículo é apresentada em "tempo real" a partir da posição fornecida por receptores GPS. Além disso, a comunicação disponível nos dias de hoje permite uma maior integração entre o veículo e o escritório. Finalmente, o Google Earth permite que se tenha acesso a uma grande quantidade de informações necessárias ao desenvolvimento de inúmeros trabalhos, permitindo inclusive a inserção de fotos e imagens para registro dos acontecimentos. O potencial deste tipo de sistema só foi possível a partir de maio de 2000, com a eliminação da SA (Selective Availability).Com isso, o posicionamento absoluto realizado por receptores de navegação (menos precisos do que os receptores geodésicos) foi aprimorado, podendo conseguir precisões da ordem de 10m, o que aumenta a qualidade de aplicações como a navegação terrestre. A proposta desta dissertação é descrever o desenvolvimento de um protótipo veicular para aplicações de campo em Geociências, onde foi incluída a navegação em tempo real, o uso da internet para a comunicação pessoal e interface de acesso ao Google Earth. O protótipo desenvolvido permite a extensão de parte da infra-estrutura de um laboratório para apoio das atividades de campo. / In our days the Global Positioning Systems (GPS) is a technology with a great variety of military and civilian applicability. Among this uses, navigation is one activity that is largely increasing in reason to lowering equipment prices and introduced facilities as easy to use technology. In practice, a system structured to navigate in terrestrial, maritime, fluvial or aerial way is formed by a GPS connected to an onboard computer and video equipped with appropriate software that process in a instantaneous mode (real time) all the information necessary to show on screen the geographical position of the vehicle. In parallel, new advances in network communication open the possibility to integrate completely the vehicle in movement with the staff in the office. Also, the Geoogle Earth™ and World Wide Web increase the facilities to view online the terrain and open the possibility to user interact directly with routines that insert local photo and images. Navigate with accuracy using a single-receiver GPS linked to a computer was only possibly after May of 2000, when the SA (Selective Availability) was excluded from GPS signal. Consequently, absolute positioning with one band handled GPS (low accuracy when compared to geodetic two bands GPS) was tested and the results show the availability to locate points in the Earth surface with an uncertainty degree not above than 10 meters (in terms of planimmetric coordinates). This performance increases the data quality and the ability of single-receiver GPS to be used to navigation purposes. In this work, it is assembled and tested a navigation system prototype installed in a vehicle with the objective to optimize field survey and adapted to some geosciences necessities, including the possibility to navigate in real time integrated with Internet facilities to personal communication and with an interface to access the Google Earth™. The configuration of the navigation system prototype elaborated in this project permit to extend to the field some facilities only accessible in a laboratory environment and consequently the results obtained with the system increased the performance of all the field work stages.
184

UM MECANISMO DE PROTECAO DE QUADROS DE CONTROLE PARA REDES IEEE 802.11

CORRÊA JÚNIOR, Marcos Antonio Costa 31 January 2012 (has links)
Made available in DSpace on 2014-06-12T16:01:28Z (GMT). No. of bitstreams: 2 arquivo9413_1.pdf: 1325696 bytes, checksum: e7de71518a27dfd5c073cfbd0f623230 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2012 / As redes sem o padr~ao IEEE 802.11 est~ao presentes nos mais diversos ambientes e continuam a expandir-se devido, principalmente, ao inegavel aumento da produtividade para as empresas. Ao mesmo tempo que se expandem, essas redes levam consigo suas vulnerabilidades. As redes sem fio contam com mecanismos para protec~ao de quadros de dados e tambem para protec~ao dos quadros de gerenciamento, apenas os quadros de controle n~ao contam com uma protec~ao padronizada pelo IEEE. A aus^encia de protec~ao possibilita atividades maliciosas que se utilizam de tecnicas de manipulac~ao, falsificac~ao e reinjec~ao de quadros de controle que geram negac~ao de servico na rede. Esta dissertac~ao prop~oe um mecanismo de protec~ao dos quadros de controle do IEEE 802.11, que faz uso de um numero de sequ^encia e de um codigo de autenticac~ao de mensagem a fim de evitar que estac~oes maliciosas, n~ao pertencentes a rede, tenha sucesso ao manipular, falsicar ou reinjetar quadros de controle que levariam a indisponibilidade da rede. O mecanismo proposto destaca-se por proteger todos os quadros de controle indistintamente, possuir um maior grau de seguranca e introduz, nesses quadros, um aumento de tamanho signi- ficativamente menor em comparac~ao aos trabalhos relacionados que tambem se prop~oe a proteger todos os quadros de controle
185

Localização em ambientes internos utilizando PDR e Wi-Fi

Santos, Marco Aurélio dos, 9292212626 16 April 2018 (has links)
Submitted by marco aurélio santos (marrco.santos@gmail.com) on 2018-07-30T01:42:52Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) msc_dissertacao_marcoSantos.pdf: 6142716 bytes, checksum: 17219663e0f7676d5c438178de493d89 (MD5) / Approved for entry into archive by Secretaria PPGI (secretariappgi@icomp.ufam.edu.br) on 2018-07-30T18:34:28Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) msc_dissertacao_marcoSantos.pdf: 6142716 bytes, checksum: 17219663e0f7676d5c438178de493d89 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2018-07-31T18:29:17Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) msc_dissertacao_marcoSantos.pdf: 6142716 bytes, checksum: 17219663e0f7676d5c438178de493d89 (MD5) / Made available in DSpace on 2018-07-31T18:29:17Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) msc_dissertacao_marcoSantos.pdf: 6142716 bytes, checksum: 17219663e0f7676d5c438178de493d89 (MD5) Previous issue date: 2018-04-16 / Internal positioning systems allow the localization of people or certain objects indoors, as well as assist in navigation and orientation. Proposals for indoor location systems based on only one technology have achieved unsatisfactory performance in localization, mainly due to the limitations in relation to the conflicting characteristics present in these environments. This work aims at the development of a hybrid location system, integrating the PDR and Wi-Fi technologies, which aims to provide the location of a user in an internal environment, allowing the user to move around and visualize their current location through a representation on a map. The results were satisfactory, including the direct influence of factors such as: physical characteristics (height, body mass, size of the past), smartphone location, speed of the adopted march and adoption of constant movements. / Os sistemas de posicionamento internos permitem a localização de pessoas ou certos objetos em ambientes internos, assim como ajudam na navegação e orientação. As propostas de sistemas de localização para ambientes internos baseados em somente uma tecnologia tem alcançado desempenho insatisfatório na localização, principalmente, devido às limitações em relação às características conflitantes presentes nesses ambientes. Este trabalho tem como objetivo o desenvolvimento de um sistema híbrido de localização, integrando as tecnologias PDR e Wi-Fi, que visa fornecer a localização de um usuário em um ambiente interno, permitindo ao usuário locomover-se e visualizar a sua localização corrente através de uma representação em um mapa. Os resultados obtidos foram satisfatórios, constando-se a direta influência de fatores como: características físicas (altura, massa corporal, tamanho da passada) do usuário, localização do smartphone, velocidade da marcha adotada e adoção de movimentos constantes.
186

Research and implementation of an indoor positioning algorithm

Liu, Honggang January 2017 (has links)
The goal of the Internet of Things’ sensing technology is to provide LBS(location-based services); a key technology is finding out how to positioning the sensing devices. For positioning outdoors, mature tech-nology such as GPS and cellular network location can be used. There is little research about indoor positioning, and there is no finished product on the market. This paper shows how to use both Wi-Fi and ZigBee signal for position-ing; Wi-Fi to find the area position and ZigBee to find the coordinate position. The main contribution of this paper is described in the follow-ing: This paper will present an algorithm using kNN on a Wi-Fi signal, as a way to find the location area of users. The GPS signal cannot be used indoors, but there are usually numerous Wi-Fi signals, that can be used for indoor positioning. In this design, to build a dataset containing the number of locations and the Wi-Fi signal strength list of each location. When indoor positioning is needed, the KNN algorithm is used to compare the user’s Wi-Fi signal strength with the dataset and find the location number. When precise positioning is needed, the ZigBee signal should be used. In this paper two different methods for precise positioning in are used, one is an improved algorithm of triangle centroid algorithm where the positioning accuracy depends on the number of anchor points and the interval of each point. The other method is the neural network method. This method could give stable result with only four anchor points. Finally, there is a comparison of the methods mentioned in this paper : the Wi-Fi fingerprint method, the ZigBee triangle centroid algorithm, and neural network method.
187

Beacone : En ny BLE beacon med Wi-Fi-stöd för uppdatering av URL / Beacone : A new BLE Beacon with Wi-Fi support for URL update

Fryxelius, Jonathan, Runeson, Johannes January 2017 (has links)
Ända sedan radion uppfanns har trådlös kommunikation varit ett mål för modern teknologi. Trots över 100 års teknologisk utveckling är radiosignaler högst relevanta, och används idag både för traditionell enkelriktad radiosändning, men också som grund för Bluetoothteknologin, som stöds av allt från bilar till telefoner och högtalare. Den här avhandlingen beskriver framtagandet av en speciell typ av Bluetoothsändare, så kallad beacon, som dessutom tillämpar trådlös nätverksanslutning för att utvidga beacons klassiska funktionalitet och ge nya möjligheter. Den nya produkten kallas Beacone. Som stöd för dess funktionalitet utvecklas ett webbgränssnitt och en mobilapplikation. Resultatet utvärderas och möjliga förbättringar diskuteras. Arbetet visar att det under flera omständigheter finns fördelar med en nätverksansluten beacon, som tillhandahåller möjligheter som inte annars hade funnits. / Ever since the invention of the radio, wireless communication has been the goal for modern technology. Despite 100 years of technological development, radio waves remain highly relevant, and are today used both in traditional one-way radio transmission, but also as the foundation for Bluetooth technology, which is supported by cars, phones, speakers, and everything in between. This report describes the development of a special Bluetooth transmitter, a so-called beacon, which also features wireless network connection to expand the traditional functionality of beacons and yield new opportunities. The new product is named Beacone. Supportive software, such as a web interface and a mobile cellphone application, is also developed. The result is evaluated, and possible improvements are discussed. The work shows that there are circumstances where Wi-Fi connectivity provides benefits which would not be available without it.
188

Modeling The Spread Malware In Computer Networks

reddy, patlolla pradeep, reddy, pasam raghava January 2009 (has links)
Our research is an exploratory study on how various parameters in the attack, ranging from that of the worm (replication rate), to those of the network (number of nodes, % fire-walled computers) as well as user behaviour (frequency of checking mail) impact the spread of malware. Through the development of a simulator we have created various experiments and have studied the impact of all possible parameters
189

Trådlös styrning av larmsystem : Kandidatuppsats

Green, Jonas, Delén, Johan January 2010 (has links)
Lansen Technology develops and sells alarm systems. The communication between the system devices are wireless. The radio protocol used by the system is developed by Lansen with the purpose to be energy efficient. The alarm systems target groups are individuals, businesses and government agencies. The current system is installed, configured and controlled from a control panel for all audiences. Some operations are also available using a mobile phone via a GSM network. Lansen Technology has a request to move more of the functionality to a mobile device and avoid the cost of using the GSM network used today. The target group for the application is primarily users that want instant access to information within the network. The project has mainly consisted of two parts. The first part of the project was to investigate two different wireless technologies that were relevant to the project. The investigation showed that Bluetooth was the best choice based on the requirements of the alarm system. Bluetooth was then integrated to the existing alarm system. The second part consisted of developing software to operate the alarm system from a PDA running Windows Mobile. An application was developed successfully and it can perform the majority of the functions specified by Lansen. The idea of remote controlling an alarm system from a mobile device has resulted in a successful project. Lansen Technology develops and sells alarm systems. The communication between the system devices are wireless. The radio protocol used by the system is developed by Lansen with the purpose to be energy efficient. The alarm systems target groups are individuals, businesses and government agencies. The current system is installed, configured and controlled from a control panel for all audiences. Some operations are also available using a mobile phone via a GSM network. Lansen Technology has a request to move more of the functionality to a mobile device and avoid the cost of using the GSM network used today. The target group for the application is primarily users that want instant access to information within the network. The project has mainly consisted of two parts. The first part of the project was to investigate two different wireless technologies that were relevant to the project. The investigation showed that Bluetooth was the best choice based on the requirements of the alarm system. Bluetooth was then integrated to the existing alarm system. The second part consisted of developing software to operate the alarm system from a PDA running Windows Mobile. An application was developed successfully and it can perform the majority of the functions specified by Lansen. The idea of remote controlling an alarm system from a mobile device has resulted in a successful project. / Lansen Technology utvecklar och säljer larmsystem. Kommunikationen mellan systemets enheter sker trådlöst. Det trådlösa radioprotokoll som används är utvecklat av Lansen med målet att vara energisnål. Larmsystemets målgrupp är privatpersoner, företag och myndigheter. Nuvarande system installeras, konfigureras och styrs från en manöverpanel. Viss manövrering kan också ske med hjälp av mobiltelefon via GSM-nätet. Önskemål från Lansen Technology finns att flytta funktionalitet till en mobil enhet och att komma ifrån trafikkostnaden på GSM-nätet. Målgruppen för applikationen är i första hand användare som omgående kräver tillgång till information från larmsystemet. Projektet har i huvudsak bestått av två delar. Första delen av projektet bestod av att utreda de två olika trådlösa tekniker som var aktuella för projektet. Utvärderingen visade att Bluetooth var det bästa valet med de krav larmsystemet ställde på uppkopplingen. Bluetooth integrerades därefter i nuvarande larmsystem. Den andra delen bestod av att utveckla en mjukvara  för att kunna manövrera larmsystemet från en handdator med Windows Mobile. Applikationen utvecklades framgångsrikt och kan utföra majoriteten av de funktioner som specificerats inför projektet. Idén med att fjärrstyra larmsystemet från en mobil enhet har resulterat i ett lyckosamt projekt. Lansen Technology utvecklar och säljer larmsystem. Kommunikationen mellan systemets enheter sker trådlöst. Det trådlösa radioprotokoll som används är utvecklat av Lansen med målet att vara energisnål. Larmsystemets målgrupp är privatpersoner, företag och myndigheter. Nuvarande system installeras, konfigureras och styrs från en manöverpanel. Viss manövrering kan också ske med hjälp av mobiltelefon via GSM-nätet. Önskemål från Lansen Technology finns att flytta funktionalitet till en mobil enhet och att komma ifrån trafikkostnaden på GSM-nätet. Målgruppen för applikationen är i första hand användare som omgående kräver tillgång till information från larmsystemet. Projektet har i huvudsak bestått av två delar. Första delen av projektet bestod av att utreda de två olika trådlösa tekniker som var aktuella för projektet. Utvärderingen visade att Bluetooth var det bästa valet med de krav larmsystemet ställde på uppkopplingen. Bluetooth integrerades därefter i nuvarande larmsystem. Den andra delen bestod av att utveckla en mjukvara  för att kunna manövrera larmsystemet från en handdator med Windows Mobile. Applikationen utvecklades framgångsrikt och kan utföra majoriteten av de funktioner som specificerats inför projektet. Idén med att fjärrstyra larmsystemet från en mobil enhet har resulterat i ett lyckosamt projekt.
190

Kartbaserad inomhuspositionering med virtuella accesspunkter / Map-aided indoor positioning using virtual access points

Lagerhult, Christopher January 2014 (has links)
Det har gjorts mycket forskning kring Positioneringssystem för inomhusbruk då många applikationer och tjänster ärberoende eller kan förbättras av det. Trots detta finns idag ingen standard för hur positionering inomhus ska fungera.För de flesta utomhusmiljöer kan en modern mobiltelefons position erhållas med ett par meters precision via GPS. I eninomhusmiljö sjunker signalen drastiskt och en precis position är svår att uppskatta. En väl etablerad teknik är Wi-Fioch kan med fördel användas då de flesta inomhusmiljöer idag redan har Wi-Fi accesspunkter installerade. Då enmottagare erhåller en signal från en accesspunkt kan distansen dem emellan uppskattas för att sedan uppskattapositionen med den matematiska tillämpningen trilateration. Då de flesta idag äger en mobiltelefon kan mobilen ageramottagare och tekniken kan således vara tillgänglig för alla.Bidraget med examensarbetet är en undersökning av den effekt virtuella accesspunkter har på ett positioneringssystemdär en trilaterationsbaserad lösning använts på Wi-Fi-signaler över både 2.4Ghz samt 5Ghz bandet i kombination med ett partikelfilter. Vidare kommer en karta nyttjas i ett försök att öka precisionen genom att skapa restriktioner för hurpositioneringen får röra sig. Resultatet visade att nyttjandet av virtuella accesspunkter ökade precisionen med drygt 10 procent och den valda kartlösningen med nästan 20 procent. / A lot of research has been made regarding indoor positioning since many applications and services are dependent or canbe improved by it. Despite this, no standard has been set for indoor positioning system concerning the best approach. Inoutdoor environments most modern smart phones can be used to estimate their position using the GPS. Indoors this isnot the case since the received signal strength is decreased drastically. A well-established technique is however Wi-Fiwhich promotes the use of it. When a receiver acquires a signal from a Wi-Fi access point the distance between them canbe estimated. Three or more known distances enables the receiver to calculate its position using a mathematicalapproach called trilateration. With the smart phone acting as the receiver, the approach is enabled for everyone.The contribution of this thesis is an investigation of the effect of using virtual access points. This will be tested in atrilateration based positioning system using both the 2.4Ghz and 5Ghz frequency band in combination with a particlefilter. In an attempt to increase the precision a map will be added into the algorithm with the intention of restricting usermovements. The attained result shows that the use of virtual access points decreased the position estimation error by approximately 10 percent, and the implemented map solution by merely 20 percent.

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