• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 4613
  • 1136
  • 1
  • Tagged with
  • 5752
  • 5752
  • 5752
  • 5752
  • 5255
  • 808
  • 605
  • 533
  • 533
  • 485
  • 349
  • 318
  • 309
  • 305
  • 268
  • 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.

A secure mobile social network

Wu, Yucheng January 2012 (has links)
Mobile social networks are a new trend to improve the quality of our life, so they should not bring any extra burden to users. The users should not anymore be worried how to set up a secure complex password and memorize it to prove their identities. The Generic Bootstrapping Architecture is used in this thesis as a novel way of authentication. The GBA protocol allows to generate and share cryptographic keys between a mobile phone and third party service providers using the operator as intermediary. These keys are generated transparently without any user interaction. In a traditional mobile social network, an Internet connection is compulsory but we believe this should not be a barrier in the future. An ad-hoc network may be used to communicate in a private group of friends. Thus, users need to be capable of verifying membership assertions and generating offline invitations for new friends without a connection to the social network server. Our implementation uses SAML assertions to certify group memberships and offline invitations. Beside these security solutions, a real mobile social network has been implemented, using the REST framework for communication and databases for storing information both on the client and the social network server. / Social Wireless Network Secure Identification

Privacy considerations for secure identification in social wireless networks

Elena, Kozhemyak January 2011 (has links)
This thesis focuses on privacy aspects of identification and key exchange schemes for mobile social networks. In particular, we consider identification schemes that combine wide area mobile communication with short range communication such as Bluetooth, WiFi. The goal of the thesis is to identify possible security threats to personal information of users and to define a framework of security and privacy requirements in the context of mobile social networking. The main focus of the work is on security in closed groups and the procedures of secure registration, identification and invitation of users in mobile social networks. The thesis includes an evaluation of the proposed identification and key exchange schemes and a proposal for a series of modifications that augments its privacy-preserving capabilities. The ultimate design provides secure and effective identity management in the context of, and in respect to, the protection of user identity privacy in mobile social networks. / swin

Metodstudier vid mobiltelefonanvändning

Albertsson, Joakim, Andersson, Sven January 2011 (has links)
Mobiltelefoner är något som nästan alla har tillgång till idag. Samtidigt ökar hela tiden användningsområdena på just mobiltelefoner. Nya modeller kommer ständigt och i takt med detta ökar även funktionaliteten av dem. Det är idag möjligt att utföra en rad andra saker än att endast ringa och skicka SMS med hjälp av sin mobiltelefon. Olika personer använder sina telefoner på olika sätt, olika mycket och till olika saker och detta har studerats på en mängd olika sätt. Att mobiltelefoner är just mobila innebär att de följer människor när de förflyttar sig och därför har även mobiltelefonanvändning på olika platser studerats. Olika metoder lämpar sig olika bra beroende på var användningen skall studeras. Den här uppsatsen syftar till att försöka få fram vilka metoder som lämpar sig för att studera mobiltelefonanvändning med hemmet som användningsmiljö. Med hjälp av litteraturstudier kom vi fram till vilka metoder som var relevanta att testa i hemmiljö och därefter har vi utfört dessa. Vi kom fram till att det inte fanns någon specifik metod som var bättre än någon annan men att resultatet blev mycket bättre om man kombinerade olika typer av metoder. / <p>This work is a contribution to the SICS project "Mobilen i hemmet" done by students at Gothenburg university.</p> / mobhome

Mobilen i hemmet - En studie om användandet av mobiltelefonen i hemmet

Fådal, Jenny, Mottaghy, Saman January 2011 (has links)
Majoriteten av den svenska befolkningen har en mobiltelefon idag 2011. Hur och i vilka situationer människor använder sig av sina mobiltelefoner har studerats vid en rad tillfällen de senaste åren. Ett återkommande resultat i dessa studier är att mobiltelefonen i förvånande stor utsträckning används i hemmet där det ofta finns ”bättre” tekniska alternativ till mobiltelefonen tillgängliga. Denna kvalitativa studie syftar därför till att studera hur mobiltelefonanvändningen i hemmet ser ut idag, för att därmed kunna fastställa vilken roll mobiltelefonen har i hemmet idag samt hur det kommer sig att den fått den betydelse som den har. Denna information kan komma att ha påverkan på vilka tjänster och funktioner som utvecklas till mobiltelefoner då vid utvecklandet av dessa är av stor relevans att veta var mobiltelefonen används samt till vad. Studien utfördes på tio testpersoner med hjälp av en dagboksstudie samt en kompletterande intervjustudie. Genom att kombinera dessa två metoder fick testpersonerna möjligheten att både föra anteckningar angående sin mobiltelefonanvändning direkt när den sker, samt att i efterhand förklara sitt mobiltelefonanvändande mer djupgående. Detta antas ge en djupare förståelse för hur mobiltelefonanvändningen ser ut i hemmet. Resultatet av studien visar att mobiltelefonen i hemmet främst används som ett medel för att kommunicera med omvärlden. Traditionella funktioner på mobiltelefonen såsom samtal och meddelanden är de som används mest. Mobiltelefonen anses vara mycket privat och ett flertal testpersoner anser sig vara beroende av den. Det vanligaste syftet för att använda mobiltelefonen i hemmet visade sig vara för att bota tristess. Mobiltelefonen uppskattas på grund av det faktum att den är snabb- och lättillgänglig. Den används mycket och ofta i hemmet men detta betyder dock inte att användarna uppfattar detta som att mobiltelefonen tar upp för mycket av deras tid. De trivs överlag med att ha den till hands. / <p>This work is a contribution to the SICS project "Mobilen i hemmet" done by students at Stockholm university.</p> / mobhome

Authorization for Industrial Control Systems

Niklas, Hjern, Jonas, Vistrand January 2014 (has links)
Every day more and more devices are getting connected to the Internet, a phenomenon commonly referred to as the Internet of Things. Since security and privacy are more important than ever before this presents an interesting problem. Suddenly devices with not even near as much computing power as a desktop computer are tasked with performing heavy security computations designed to be used in powerful systems with little resource and power limitations. This thesis presents a solution for performing authorization for a resource limited system using a trusted third party, thus transferring the usually quite heavy authorization computations from a resource constrained device to another device where no such restrictions exists. When a client wishes to request a resource on the constrained device it must first retrieve authorization information from the third party and include this in the request. The authorization information is then validated by confirming that it originates from the trusted third party using a shared secret. In this thesis the constrained system is represented by an ABB control system of model 800xA and by transferring the authorization cost to another system the increased amount of resource usage on this device is kept to a minimum. It is also shown that this increase is negligible compared to the increase in resource usage when authentication and message protection in the form of TLS was implemented. / <p>Thesis conduced in cooperation with ABB AB. Supervisors: Ludwig Seitz - SICS, Andreas Bäckman - ABB</p>

Studie av 3d-visualiserad interaktiv monteringsanvisning : För pulsgivare

Höglind, Mattias January 2007 (has links)
No description available.

Tempus Custode : En GPS-tidrapporteringsapplikation

Fryxelius, Peter, Oscar, Ternström January 2014 (has links)
This paper describes Tempus Custode, a smartphone application with which the user may register working hours and travel time during the work day. The application communicates with a database via a server. The data stored in the database may be manipulated using an administrator tool, mainly for the composition of time reports. In this way, the user’s task of time reporting his day is greatly simplified. The application is able to automatically discriminate between work time and travel time, as it continuously fetches positioning data from the smartphone GPS receiver. There is a personal integrity issue inherent in this operation, because an employer may supervise an employee’s position during the work day. The application may still, with some qualifications, be in accordance with the Swedish Personal Data Act. The Tempus Custode project comprises one tentatively complete application that runs on all modern smartphones. A simple server has been implemented, together with a database. The administrator tool has not been developed. Data in the database are otherwise viewed and manipulated. The results of testing the system have been satisfactory, leading the authors to claim that the project’s objective has been fulfilled: Tempus Custode can significantly simplify the work day of the user, by offering simple, semi-automatic, GPS time reporting. / Denna uppsats beskriver Tempus Custode, en smarttelefonapplikation med vilken användaren kan registrera arbetstid och restid under arbetsdagen. Applikationen kommunicerar via en server med en databas. Datan som sparas i databasen kan manipuleras med ett administratörsverktyg, främst för att skapa färdiga tidrapporter. På så sätt kan användarens arbete med att tidrapportera sin dag avsevärt förenklas. Applikationen diskriminerar själv mellan arbetstid och restid, genom att applikationen löpande hämtar GPS-data från smarttelefonens GPS-mottagare. Det finns ett integritetsproblem i och med detta förfarande, eftersom arbetsgivaren kan följa den anställdes position under arbetsdagen. Applikationen kan ändå, under vissa förutsättningar, sägas följa personuppgiftslagen. Projektet Tempus Custode består av en mer eller mindre färdigutvecklad applikation som fungerar på alla moderna smarttelefoner. En enkel server har implementerats, tillsammans med en databas. Däremot finns inget utvecklat administratörsverktyg, utan data i databasen beskådas och manipuleras på annat sätt. Resultaten från tester av systemet har varit tillfredsställande och leder författarna att hävda, att målet för projektet har uppnåtts: Tempus Custode kan väsentligt förenkla användarens arbetsdag, genom att erbjuda enkel, semiautomatisk GPS-tidrapportering.

Measuring and Monitoring Battery Status

Owona, Ignace Flavien January 2014 (has links)
Embedded systems are the most widespread technologies today. These technologies include hardware and software. We may meet them from simple household appliances such as the washing machine and microwave oven to more sophisticated appliances such as aircraft, medical appliances, and automobiles not to mention mobile phones, TVs and radio receivers, leisure gadgets, etc. This project thesis goal is the measurement and the monitoring of the discharge of the battery used as the energy supplier in a quadrocopter. Its particularity is that the battery monitoring is done remotely through a radio link in embedded systems. To do this, the discharge of the battery will be measured by a hardware called the charge measurer which will measure how much charge flows from the battery. The status of the battery will be transmitted to the ground by a radio transmitter device and it will be received by a radio receiver module. The monitoring of the battery status will be carried out by software implemented in IAR Embedded systems. The Monitoring of the status of the battery will happen from the ground when the quadrocopter flies. When the quadrocopter flies the user will know how fast the energy is consumed and when the flight is over, the user will know how much energy was consumed. This can help the user to monitor the energy consumption and to know when it is possible to land the appliance safely. To perform this project several important tasks will be done such as:   -Conception and the design of the current measurer circuitry -Design of the printed circuit -Laboratory testing -Simulation of the electronic circuit with the help of some tools like Orcad and PSpice -Mounting of the electronic components on the printed circuit board -Design of the software -Writing the C code in the platform IAR Embedded system

Online inference of topics : Implementation of the topic model Latent Dirichlet Allocation using an online variational bayes inference algorithm to sort news articles

Wedenberg, Kim, Sjöberg, Alexander January 2014 (has links)
The client of the project has problems with complex queries and noisewhen querying their stream of five million news articles per day. Thisresults in much manual work when sorting and pruning the search result of their query. Instead of using direct text matching, the approachof the project was to use a topic model to describe articles in terms oftopics covered and to use this new information to sort the articles. An online version of the topic model Latent Dirichlet Allocationwas implemented using online variational Bayes inference to handlestreamed data. Using 100 dimensions, topics such as sports and politics emerged during training on a 1.7 million articles big simulatedstream. These topics were used to sort articles based on context. Theimplementation was found accurate enough to be useful for the client aswell as fast and stable enough to be a feasible solution to the problem.

Scaling an Optimization Engine for a Decision Support System

Sandvik, Joel Emil January 2013 (has links)
The objective of this survey has been to determine whether an existing linearprogramming model could be used to implement a system for the optimizationwith regards to the matching of transports and requests. Realdata from Härnösands harbour was enhanced and used to simulate scenariosthat would be used and applied within the system. The LINGOsolverwas integrated within a system that was developed in .Net to addressissues around data in- and output, data persistence, and stability.Performance tests revealed that the system and model performed inadequatelyon larger datasets. A simpler model was developed that handlea subset of the types of datasets handled by the first model, a subsetwhich includes the data collected from Härnösand harbour. The simplermodel was implemented with the AMPL/CPLEX-solver software, and furthertests showed that this provided a much improved performance to thesystem. These results indicate that further investigation might be requiredregarding the differences in performance between combinations of differentsolvers and models, and that a complete and production ready systemis likely to benefit from incorporation of various models that can be appliedto various characteristics of the input data.

Page generated in 0.1871 seconds