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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.
41

Vers un après- tourisme ? : la figure de l'itinérance récréative pour repenser le tourisme de montagne : études des pratiques et de l'expérience de l'association Grande Traversée des Alpes / Towards after-tourism ? : the case of recreational roaming for a rethink of mountain tourism : study of the practices and experience of the Grande Traversée des Alpes association

Berthelot, Libéra 29 June 2012 (has links)
Notre démarche de recherche souhaite se positionner au regard des débats contemporains en sciences sociales autour de la mobilité (KAUFMANN, VIARD, LEVY, LUSSAULT, URRY, STOCK) et plus particulièrement de la mobilité récréative (MIT, MICHEL, REAU, COUSIN, DEWAILLY, BOURDEAU, CHRISTIN). Ce positionnement nous amène à nous inscrire au sein d'une géographie culturelle considérée parfois comme ayant pris un tournant sociologique (STASZAK, 2004). En suivant l'agencement chronologique proposé dans ce manuscrit, le lecteur découvrira en premier lieu une présentation des enjeux théoriques induits par la prise en compte des pratiques récréatives en mouvement. Le premier chapitre propose de cerner les mutations des rapports entre société et mobilités au sens large et de réfléchir à l'apport de la postmodernité pour mieux les saisir. Le second chapitre resserre quant à lui l'analyse sur une notion et une pratique particulière : l'itinérance. A travers une approche géo-culturelle, l'intention donnée à ce chapitre est d'en saisir les contours et l'intérêt au regard des notions existantes pour aborder les pratiques récréatives. La deuxième étape souhaite positionner l'itinérance (pédestre) dans le champ des pratiques récréatives : quelle place et quels apports ? Pour cela, le troisième chapitre dresse un panorama des enjeux heuristiques présents dans le champ du tourisme en faisant état des différents positionnements de recherche possibles et des notions en émergence. Le chapitre quatre, à travers l'analyse des récits d'expériences d'itinérants pédestres, souhaite valider l'apport du post-tourisme pour saisir les arrangements proposés par ces pratiques. Ce parcours, lorsqu'il est suivi de manière linéaire, se termine par une partie entièrement consacrée à la GTA et son positionnement dans le champ des pratiques récréatives, et plus particulièrement dans le "millefeuille" de l'itinérance récréative : s'agit-il d'une alternative pour l'aménagement et le tourisme alpin ou d'une forme moderne du tourisme itinérant ? Pour y répondre, le chapitre cinq analyse la singularité de l'association dans le paysage alpin à l'échelle française comme à l'échelle européenne. Le chapitre 6 établit l'idée que la GTA est une structure de l'entre-deux à la fois gestionnaire d'itinéraires et animatrice d'une filière. / Our research approach is a contribution related to the contemporary social sciences debate around mobility (KAUFMANN, VIARD, LEVY, LUSSAULT, URRY, STOCK) and especially recreational mobility (MIT, MICHEL, REAU, COUSIN, DEWAILLY, BOURDEAU, CHRISTIN). Therefore our field of work is cultural geography, sometimes seen as having taken a sociological turn (STASZAK, 2004). Following the chronological order of this manuscript, the reader will first encounter a presentation of the theoretical issues linked to the consideration of recreational practices “in motion”. The first chapter aims at identifying the mutations of the relationships between society and mobility in a broad sense, and reflecting about the input of post modernity in order to apprehend them better. The second chapter focuses the analysis on a specific notion and practice: “itinérance”, i.e. recreational travel. The aim of this chapter is to identify its outline and interest, through a geo-cultural approach basing on the existing notions to study recreational practices. In a second stage, recreational travel (on foot) is positioned within the area of recreational activities: which place and which contributions? To that effect the third chapter sets out a panorama of heuristic issues in the field of tourism, presenting the various possible research approaches and emerging notions. The fourth chapter, through the analysis of experience accounts of walkers, aims at validating the input of post-tourism in order to apprehend the compromise linked to these practices. When followed in a linear way, this route ends with a part entirely dedicated to GTA and its integration in the field of recreational practices, and especially in the “layer cake” of recreational travel: is it an alternative for territorial development and alpine tourism or a modern form of travelling tourism? In order to provide an answer, chapter five analyses the singularity of this association in the alpine landscape both at the French and European levels. Chapter 6 establishes the idea that GTA is a structure of the in-between, both manager of tourist routes and coordinator of an activity chain.
42

Roaming User Profiles : En undersökning av olika versioner och dess kompatibilitet

Carlsson, Anders, Johansson, Simon, Svedlund, Jacob January 2010 (has links)
<p>När Windows Vista introducerades förändrades mappstrukturen för hur användarprofilen sparas jämfört med tidigare Windowsversioner såsom Windows XP. Denna rapport undersöker kompatibilitetsproblem med Roaming User Profiles mellan äldre och nyare versioner av operativsystemet. Syftet med rapporten var att utreda vilka problem som kan uppstå, vad det gäller Roaming User Profiles, vid en övergång från Windows XP till Windows Vista eller 7. Undersökningen genomfördes med hjälp av laborationer, litteratur och tester för att hitta problemen såväl som lösningar till dem. Resultatet visar att profiler skapade med Windows XP inte följer med till Windows Vista eller 7 utan det skapas sammanlagt två olika profiler, en för det äldre och en för det nyare operativsystemet. Ett skript som kopierar en användares filer från Windows XP till Vista/7 utformades därför. Slutligen presenterades en handlingsplan med olika alternativ vid en övergång från Windows XP till den nyare generationen av operativsystemen i Windowsfamiljen. Folder Redirection är en väl fungerande lösning dock går funktionaliteten som Roaming User Profiles erbjuder förlorad eftersom man endast får en uppmappning av bl.a. ”Mina Dokument” och ”Start Menu”.</p>
43

Secure Management System for UPnP Digital Home Network

Lu, Yu-Chun 16 August 2010 (has links)
The rapid development in wireless network technology, together with the extensive progress in the digital home hardware and software, have allowed every family to enjoy the conveniences of these new technologies. In particular, the UPnP network technologies link various digital home devices together, coming alone with seamless connection and configuration-less environment. These benefits make it very easy for users to enjoy their digital home devices. However, related security issues have begun to surface one after another. Under a UPnP network environment, users¡¦ identity are not distinguished and therefore, they can not authorize the usage of those devices, services and content. Devices with similar types of service and content lack of integration, it is inconvenient when users need to search or access. In addition, there seems to be a lack of proper handling mechanisms when these devices, services, and content encounter anomaly problems and errors. Lastly, family users will also inevitably have connection requirements between homes but unfortunately, the current UPnP network environment is unable to provide convenient and secured home-to-home content exchange mechanisms. To address the issues mentioned above, this study surveyed the UPnP network environment from a fresh perspective. And through virtual resources, central control network framework and fault tolerance design, it further provides abilities to do related resource authentication, authorization, auditing, and fault handling. It also uses PKI framework to provide the authentication and secure connection between homes. Lastly, we designed and implemented a secure Management System for a UPnP digital home network. It provides secure and convenient home network environment that is compatible with UPnP/UPnP AV standards. On the user¡¦s control aspect, we provided user authentication, authorization, and auditing functionalities. On the home resource management aspect, we provided networks, devices, services, and content which can be controlled and managed. And we also provide integrated and customized entries for service and content. We have a management system with smart and user friendly features. On the anomaly management aspect, we provide fault detection, handling, and basic fault tolerance mechanism. Lastly, we provide trusted homes mechanism, supporting secure user roaming outside their homes, allowing content sharing between trusted homes, and ensuring that users roaming in other locations may still access specific content in their homes.
44

Design and comparative evaluation of handover schemes in mobile wimax networks

Alatise, Mary Bosede. January 2013 (has links)
M. Tech. Electrical Engineering. / Proposes certain approaches aimed at improving handover from the users point of view, the benefits may include enhanced quality of service, avoidance of handover disruption and reduction of handover rate, irrespective of high traffic loads at the BSs.The proposed scheme improves the network performance by minimising the handover delay time and also enhancing the effective use of radio resources
45

Improvement of internet protocol (IP) mobility support in vehicular scenarios

Banda, Laurence. January 2013 (has links)
M. Tech. Electrical Engineering. / Presents an IPv6-based mobility support scheme for vehicular scenarios. The focus of this study is on modelling of an efficient network layer handover scheme suitable for vehicular network environments. In order to achieve this, a Vehicular Fast handovers for Mobile IPv6 (VFMIPv6) network layer protocol has been proposed.
46

Gestion multi-agents du spectre pour des terminaux mobiles à radio cognitive / Multi-agents spectrum management for mobiles cognitive radio terminals

Trigui, Emna 03 December 2013 (has links)
Cette thèse s’intéresse aux concepts de mobilité et de gestion du spectre dans les réseaux à radio cognitive. Ainsi, nous avons proposé deux approches décentralisées basées sur les systèmes multi-agents (SMA). Nous avons, tout d’abord, intégré des agents au sein des utilisateurs secondaires (n’ayant pas de licence pour l’accès au spectre) et des utilisateurs primaires (disposant d’une licence) et nous avons défini leurs comportements au moment du handover. Notre première solution NESAM propose un mécanisme de négociation entre les agents permettant aux utilisateurs secondaires de se voir allouer une bande de spectre avec un bon rapport prix par durée d’allocation. Nous avons, par ailleurs, proposé une deuxième solution LASMA qui se base sur l’enchère combinée avec de l’apprentissage pour assurer une gestion efficace du spectre ainsi qu’une gestion de la mobilité des utilisateurs à radio cognitive. Nos algorithmes prennent en compte les préférences des utilisateurs, comme la fréquence spectrale, le prix et la durée ainsi que les contraintes de l’environnement spectral telles que les bandes de fréquences disponibles. Nos propositions assurent une exploitation importante des ressources spectrales tout en diminuant le nombre de handovers spectraux. De plus, nos algorithmes offrent un handover spectral transparent et sans interruption lors des déplacements des utilisateurs. Nous avons prouvé également que nos solutions permettent de satisfaire les besoins des utilisateurs et d’améliorer leur utilité / In this thesis, we are interested in mobile cognitive radio networks while ensuring an efficient spectrum sharing and seamless handover at the same time. Hence, we propose two decentralized approaches based on multi-agents systems. We first deployed agents on each primary (licensed) and secondary (unlicensed cognitive radio) users, respectively. Besides, we define agents’ behaviors during the handover process.Our proposal NESAM defines a novel negotiation mechanism between agents to allow secondary users assigning the appropriate spectrum band giving a good price for the use duration. We have also proposed a second solution LASMA using the learning based auctions. Our algorithms take into account users’ requirements such as spectrum frequency, price and duration as well as environment’s constraints such as available resources.Our proposals improve the overall spectrum utilization and minimize the number of spectrum handovers when users move from one network to another one. This proves that our algorithms ensure efficient spectrum allocation and enable seamless handover during user’s mobility. Besides, we proved that our approaches guarantee users’ satisfaction and improve their utility
47

Roaming User Profiles : En undersökning av olika versioner och dess kompatibilitet

Carlsson, Anders, Johansson, Simon, Svedlund, Jacob January 2010 (has links)
När Windows Vista introducerades förändrades mappstrukturen för hur användarprofilen sparas jämfört med tidigare Windowsversioner såsom Windows XP. Denna rapport undersöker kompatibilitetsproblem med Roaming User Profiles mellan äldre och nyare versioner av operativsystemet. Syftet med rapporten var att utreda vilka problem som kan uppstå, vad det gäller Roaming User Profiles, vid en övergång från Windows XP till Windows Vista eller 7. Undersökningen genomfördes med hjälp av laborationer, litteratur och tester för att hitta problemen såväl som lösningar till dem. Resultatet visar att profiler skapade med Windows XP inte följer med till Windows Vista eller 7 utan det skapas sammanlagt två olika profiler, en för det äldre och en för det nyare operativsystemet. Ett skript som kopierar en användares filer från Windows XP till Vista/7 utformades därför. Slutligen presenterades en handlingsplan med olika alternativ vid en övergång från Windows XP till den nyare generationen av operativsystemen i Windowsfamiljen. Folder Redirection är en väl fungerande lösning dock går funktionaliteten som Roaming User Profiles erbjuder förlorad eftersom man endast får en uppmappning av bl.a. ”Mina Dokument” och ”Start Menu”.
48

Smart Grid security : protecting users' privacy in smart grid applications

Mustafa, Mustafa Asan January 2015 (has links)
Smart Grid (SG) is an electrical grid enhanced with information and communication technology capabilities, so it can support two-way electricity and communication flows among various entities in the grid. The aim of SG is to make the electricity industry operate more efficiently and to provide electricity in a more secure, reliable and sustainable manner. Automated Meter Reading (AMR) and Smart Electric Vehicle (SEV) charging are two SG applications tipped to play a major role in achieving this aim. The AMR application allows different SG entities to collect users’ fine-grained metering data measured by users’ Smart Meters (SMs). The SEV charging application allows EVs’ charging parameters to be changed depending on the grid’s state in return for incentives for the EV owners. However, both applications impose risks on users’ privacy. Entities having access to users’ fine-grained metering data may use such data to infer individual users’ personal habits. In addition, users’ private information such as users’/EVs’ identities and charging locations could be exposed when EVs are charged. Entities may use such information to learn users’ whereabouts, thus breach their privacy. This thesis proposes secure and user privacy-preserving protocols to support AMR and SEV charging in an efficient, scalable and cost-effective manner. First, it investigates both applications. For AMR, (1) it specifies an extensive set of functional requirements taking into account the way liberalised electricity markets work and the interests of all SG entities, (2) it performs a comprehensive threat analysis, based on which, (3) it specifies security and privacy requirements, and (4) it proposes to divide users’ data into two types: operational data (used for grid management) and accountable data (used for billing). For SEV charging, (1) it specifies two modes of charging: price-driven mode and price-control-driven mode, and (2) it analyses two use-cases: price-driven roaming SEV charging at home location and price-control-driven roaming SEV charging at home location, by performing threat analysis and specifying sets of functional, security and privacy requirements for each of the two cases. Second, it proposes a novel Decentralized, Efficient, Privacy-preserving and Selective Aggregation (DEP2SA) protocol to allow SG entities to collect users’ fine-grained operational metering data while preserving users’ privacy. DEP2SA uses the homomorphic Paillier cryptosystem to ensure the confidentiality of the metering data during their transit and data aggregation process. To preserve users’ privacy with minimum performance penalty, users’ metering data are classified and aggregated accordingly by their respective local gateways based on the users’ locations and their contracted suppliers. In this way, authorised SG entities can only receive the aggregated data of users they have contracts with. DEP2SA has been analysed in terms of security, computational and communication overheads, and the results show that it is more secure, efficient and scalable as compared with related work. Third, it proposes a novel suite of five protocols to allow (1) suppliers to collect users accountable metering data, and (2) users (i) to access, manage and control their own metering data and (ii) to switch between electricity tariffs and suppliers, in an efficient and scalable manner. The main ideas are: (i) each SM to have a register, named accounting register, dedicated only for storing the user’s accountable data, (ii) this register is updated by design at a low frequency, (iii) the user’s supplier has unlimited access to this register, and (iv) the user cancustomise how often this register is updated with new data. The suite has been analysed in terms of security, computational and communication overheads. Fourth, it proposes a novel protocol, known as Roaming Electric Vehicle Charging and Billing, an Anonymous Multi-User (REVCBAMU) protocol, to support the priced-driven roaming SEV charging at home location. During a charging session, a roaming EV user uses a pseudonym of the EV (known only to the user’s contracted supplier) which is anonymously signed by the user’s private key. This protocol protects the user’s identity privacy from other suppliers as well as the user’s privacy of location from its own supplier. Further, it allows the user’s contracted supplier to authenticate the EV and the user. Using two-factor authentication approach a multi-user EV charging is supported and different legitimate EV users (e.g., family members) can be held accountable for their charging sessions. With each charging session, the EV uses a different pseudonym which prevents adversaries from linking the different charging sessions of the same EV. On an application level, REVCBAMU supports fair user billing, i.e., each user pays only for his/her own energy consumption, and an open EV marketplace in which EV users can safely choose among different remote host suppliers. The protocol has been analysed in terms of security and computational overheads.
49

Low cost secure network connectivity for a municipal organization

Gutti, Krishna January 2005 (has links)
Wireless Local Area Networks (WLANs) based on 802.11 technology were initially conceived with the aim of providing wireless connectivity to client devices in limited areas, such as office buildings, homes, etc. or in places where wires are too expensive to be placed. This ‘anywhere’ connectivity is said to have improved worker’s productivity by allowing one to work flexibly from various places besides one’s desk. Currently we are witnessing the growth of both public and private networks based on WLAN technology. Such hotspots are usually limited to the network owner’s premises such as her office, campus, etc. This limits the total coverage area of this network. It is often not economically feasible for a network access provider to install Access Points at all places that a network user might go. This has become a problem for many network access providers; a sensible solution would be to collectively address the problem by entering into roaming agreements as is already done by most Wide Area Wireless Network providers. Such operator specific roaming agreements can provide nearly continuous coverage over a much wider area such as an entire city. One of the goals of this project was to study potential cost effective technical solutions that provide WLAN access to City of Stockholm’s network based on 802.11 technologies; including evaluation from different technical aspects (e.g., capacity enhancements, improvements in handover latency, etc). Proper deployment and management strategies were also evaluated. Technologies permitting differentiated services for users, enabling provisioning of Voice over Wireless Local Area Network (VoWLAN) services and other interactive services were studied. Technologies for authentication, authorization and accounting were studied. Additionally technical means of providing secure access to the wireless network were investigated. Evaluation of architectures that allow inter-operator roaming were made. Today’s corporate users are increasingly mobile and there is a need to provide secure access to corporate data to these mobile users. The coverage offered by WLAN networks even with large roaming agreements would still have coverage gaps which can be reduced by relying on the 3G networks which are being widely deployed. Virtual Private Network technologies are successfully used for providing secure remote access to data and Mobile IP technology provides application persistence to mobile users even while switching between networks (e.g., WLAN to 3G). There is a need for them to co-exist in order to provide secure, mobile access to data. Such secure mobile access could also be provided without relying on the above, standardised solutions. A goal of this master’s thesis was to evaluate the technical solutions to enable such secure, mobile access to data. Current products were evaluated and a suggestion of suitable products for the City of Stockholm was given. The above solutions together would provide the City of Stockholm with secure wireless network connectivity[.] / Trådlös Lokal Areal Nätverken (WLANs) baserat på 802.11 teknologien var i början uppfattade med det sikta med av skaffande trådlös anslutning till klienten anordningen i inlemmat områdena , sådan som kontor byggnad , hemmen etc. eller på platsen var tråden är alltför dyr till vara placerat. Den här ‘var som helst’ anslutning är sa till har förbättrat arbetaren produktiv vid tillåt en till verk böjlig från olika ställen for resten en’s skrivbord. Just nu vi er vittne växten av båda allmänhet och privat nätverken baserat på WLAN teknologien. Sådan hotspots är vanligtvis inlemmat till nätverken ägare lokalerna sådan som henne kontor, läger etc. Den här gränsen den räkna samman täckningen areal av de här nätverken. Den er ofta inte ekonomisk genomförbar till installera Tillträde Meningen i det hel tåt ställen så pass nätverken förbrukaren makt gå. Den här har bli ett problem för många nätverk skaffa; en förståndig lösande skulle bli till samlad adress problemet vid inlåtande in i att ströva avtalen så är redan gjort vid mest Vid Areal Trådlös Nätverken skaffa. Sådan operatör bestämd ströva avtalen kanna skaffa nästan kontinuerlig täckningen över en mycket vid areal sådan som en hel stor stad. En om målarna av det här projektet var till att studera potential kostnad effektiv teknisk lösandet så pass skaffa WLAN tillträde till Stor stad av Stockholm nätverken baserat på 802.11 teknologerna inklusive bedömningen från olik teknisk aspekterna (e.g., utrymme förstärkningarna , förbättringarna i handover latent tillstånd etc). Rätt spridandeen och företagsledning strategisk var också värderat ut. Teknologerna tillåt skilj tjänsten för förbrukaren, sättande i stånd till tillhandahållande av Röst över Trådlös Lokal Areal Nätverken (VoWLAN) tjänsten och annan interaktiv tjänsten var studier. Teknologerna för authentication, bemyndigandena och räkenskapen var studier. Ytterligare tekniskt medel av skaffande befästa tillträde till trådlös nätverken var undersöka. Bedömningen av arkitekturen så pass tillåta begrava - operatör ströva var gjord. Idag gemensam förbrukaren är alltmer rörlig och där er en behov till skaffa befästa tillträde till gemensam datan till de här rörlig förbrukaren. Täckningen erbjudande vid WLAN nätverken evn med stor ströva avtalen skulle stilla har täckningen öppning vilken kanna bli nedsatte vid användande den 3G nätverken vilken er vida spridde. Verklig Privat nätverk teknologerna ni är lyckosam använd för skaffande befästa avlägsen tillträde till datan och Rörlig IP teknologien skaffar applicering hårdnackenheten till rörlig förbrukaren jämn fördriva tiden kopplande emellan nätverken WLAN till 3G). Där er ett behov för dem till tillpass - finnas for att skaffa befästa, rörlig tillträde till datan. Sådan befästa rörlig tillträde kunde också bli försynt utan tillit till den över, standardiserat lösandet. En målet av den här övervinna teorin var till att bedöma den teknisk lösandet till möjliggöra sådan befästa, rörlig tillträde till daton. Ström produkten var värderat ut och en förslagen av passande produkten för staden av Stockholm var givit. Den över lösandet tillsammans skulle skaffa staden av Stockholm med befästa trådlös nätverken anslutning[.]
50

The Influence of Food Distribution and Relatedness on the Social Behaviours and Proximities of Free-Roaming Cats (Felis silvestris catus)

Shreve, Kristyn R. 06 November 2014 (has links)
No description available.

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