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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.
31

Contamination des mollusque bivalves et des végétaux par les protozoaires Cryptosporidium, Giardia et Toxoplasma / Contamination of bivalve molluscs and plants by the protozoa Cryptosporidium, Giardia and Toxoplasma

Hohweyer, Jeanne 04 October 2013 (has links)
Les infections d'origine alimentaire constituent un problème de santé publique majeur et présentent un impact économique important. Les agents pathogènes incriminés peuvent être d'origine bactérienne, virale ou parasitaire. Les conséquences de ces infections sur la santé des consommateurs peuvent être majeures, en fonction du statut immunitaire de chaque individu et de la provenance de l'agent infectieux, la mondialisation ayant accru les risques de dissémination de pathogènes viables virulents. Les denrées à risque sont principalement les aliments frais consommés crus ou peu cuits. Ceux-ci sont irrigués en continu durant leur croissance par des eaux pouvant être potentiellement contaminées par des agents infectieux.Au cours de ce travail, nous avons développé une stratégie d'extraction et de détection des parasites Toxoplasma gondii, Cryptosporidium et Giardia à partir de basilic et de framboise. Nous avons pour cela développé une technique d'immuno-capture des oocystes de Toxoplasma gondii grâce à un anticorps monoclonal dirigé contre la paroi des oocystes ainsi que des techniques de détection des trois parasites par qPCR. Ces protocoles ont été validés par des essais inter-laboratoires avec la participation de quatre laboratoires partenaires de ce projet. Nous avons par la suite cherché à mieux appréhender les risques réels pour les consommateurs en réalisant une étude mettant en parallèle une Reverse transcriptase PCR avec des essais in vivo, permettant ainsi de mettre en corrélation la viabilité des parasites avec leur infectiosité.Ce travail contribue à mieux maitriser les risques sanitaires liés à la présence de parasites dans lesdenrées alimentaires , par le biais d'une stratégiesusceptible d'être proposée aux industriels et normalisée. / Foodborne infections are a major public health problem and have a significant economic impact. Pathogens implicated in these outbreaks can be bacteria, viruses and parasites. Their impact on the consumer's health can be significant, depending on the immune status of the person and the pathogen source. Globalization has increased the risk of spreading of viable and virulent . The food at risk is mainly fresh food, eaten raw or undercooked, which has been widely irrigated by potentially contaminated waters during production. In this study, we have developed methods to extract and detect Toxoplasma gondii, Cryptosporidium and Giardia parasites from basil and raspberry with techniques able to detect the three parasites by qPCR. In this aim, we have developed a technique for the immuno-capture of Toxoplasma gondii oocysts using a monoclonal antibody directed against the oocyst wall. These protocols have been validated by interlaboratory trials with the participation of four laboratories involved in the same project. We have subsequently sought to better understand the real risks for consumers by undertaking a study of Reverse transcriptase PCR in parallel with in vivo, thus allowing to correlate the viability of parasites with their infectivity. This work contributes to a better control of health risks associated with food and presence of parasites, through a strategythat could be standardized and offered to industrial partners.
32

L'auto-diagnostic dans les réseaux autonomes : application à la supervision de services multimédia sur réseau IP de nouvelle génération / Self-diagnosis in autonomic networks : application to the supervision of multimedia services on next generation IP network

Lu, Jingxian 19 December 2011 (has links)
Les réseaux autonomes représentent un intérêt certain pour les opérateurs de télécommunications. L’auto-diagnostic, pour la détection des pannes et des dysfonctionnements, est une fonction critique dans le cadre de ces réseaux.Nous avons opté pour l’utilisation d’un diagnostic à base de modèles car il permet un diagnostic automatique, distribué et adapté à l'architecture des réseaux autonomes. Ce diagnostic est basé sur une modélisation explicite des comportements normaux ou anormaux du système. Nous utilisons ensuite un algorithme de diagnostic générique qui s'appuie sur cette modélisation pour réaliser l’auto-diagnostic. La modélisation utilisée est à base de graphe causal. Elle est une représentation intuitive et efficace des relations de causalités qui existent entre les observations et les pannes.Notre algorithme d’auto-diagnostic qui s’appuie sur l’utilisation de graphes causaux, fonctionne sur le principe suivant : lorsqu’une alarme est déclenchée, l’algorithme est lancé et, grâce aux relations de causalité entre l’alarme et les causes, les causes primaires vont pouvoir être localisées. Puisque le graphe causal permet une modélisation modulaire et extensible, il est possible de le séparer ou de le fusionner pour répondre aux besoins des services et architectures de communication. Cette caractéristique nous permet de proposer un algorithme distribué qui s’adapte à l’architecture des réseaux autonomes. Nous avons, ainsi, proposé un algorithme d’auto-diagnostic qui permet de réaliser le diagnostic distribué correspondant à l’architecture du réseau autonome afin de réaliser un diagnostic global.Nous avons implémenté cet algorithme sur une plateforme OpenIMS, et nous avons montré que notre algorithme d'auto-diagnostic pourrait être utilisé pour différents types de service. Les résultats obtenus correspondent bien à ce qui est attendu. / The autonomic networks show certain interest to manufacturers and operators of telecommunications. The self-diagnosis, the detection of failure and malfunction, is a critical issue in the context of these networks.We choose based-model diagnosis because it allows an automatic diagnosis, and is suitable to distributed network architecture. This diagnosis is based on an explicit modeling of normal and abnormal behavior of the system. We then use a generic diagnostic algorithm that uses this modeling to perform self-diagnosis. The modeling used is based on causal graph. It is an intuitive and efficient representation of causal relationships between observations and failures.The self-diagnosis algorithm we proposed based on the use of causal graphs. The principle is: when an alarm is triggered, the algorithm is run and, with the causal relationships between alarms and causes, the principal causes will be located. Since the causal graph modeling allows a modular and extensible model, it is possible to separate or merge according to the needs of services and communication architectures. This feature allows us to propose a distributed algorithm that adapts to autonomic network architecture. We have thus proposed a self-diagnosis algorithm that allows for the diagnosis corresponding to the autonomic network architecture to realize a global diagnosis.We have implemented this algorithm on a platform OpenIMS, and we showed that our self-diagnostic algorithm could be used for different types of services. The results of implement correspond to what is expected.
33

Řešení bezpečnosti v IMS / IMS security solutions

Porubský, Tomáš January 2009 (has links)
In the first part of my master's thesis the network architecture of IMS (IP Multimedia Subsystem) is presented. The database of subscribers HSS (Home Subscriber Server) and SLF (Subscription Locator Function), as well as a SIP CSCF servers (Call Session Control Functions) process a SIP signalization and an AS application server performing services, etc. I focus on the registration of subscribers in the IMS network with a list of transmitted messages and description of each interface that is used in this network. The most important interfaces, which I described here, are Gm, Mw, Cx, Dx and Sh. Then I focused on security in IMS problems, which are divided into categories of access security and network security. After that is the implementation of IMS network in an open source Open IMS Core System considered under the Linux operating system. Here is the problem description from the actual system installation, through the configuration of all necessary elements of the network to the communication party itself. The communication analysis in the initial registration process and in subsequent communications is described. Finally I created laboratory exercises with a focus on the Open IMS Core System, where students learn about architecture and principle of networks based on IMS technology operation, with individual elements necessary for the operation of the network and their configuration. Students also test simple captured traffic analysis.
34

IP Multimedia for Municipalities : The supporting architecture

Peterström, Dan January 2009 (has links)
Fiber deployment is becoming popular and is seen as a way to increase a community’s attractiveness to new inhabitants and companies. A new Open Access network is emerging, leading to a more horizontal network architecture. Combining this architecture with IMS enables developers to easily develop new and attractive services. To facilitate the development of new IMS services there needs to be an easy to use development environment and a reliable hardware/software platform upon which to deploy them. This thesis project will explore the design, development, and evaluation of new IMS applications targeted at municipal networks as well as the service platforms they are deployed on. The thesis will also examined what role IMS plays in Municipalities and why they may need a tailored IMS solution. During the thesis a reference network for Municipalities was put together and tested. Different service platforms were tested and evaluated. / Fiberutbyggnad har blivit mycket populärt och ses som ett sätt att öka en stads attraktivitet för nya invånare och företag. Ett nytt öppen nät håller på att växa fram, detta leder till en mer horisontell nätverksarkitektur. Kombinera denna arkitektur med IMS så kan utvecklare lättare utveckla nya och attraktiva tjänster. För att underlätta utvecklingen av nya IMS-tjänster måste det finnas ett lättanvänd utvecklingsmiljö och en pålitlig hårdvaru/mjukvaru plattform att installera dem på. Detta examensarbete kommer att undersöka design, utveckling och utvärdering av nya IMSlösningar riktade till standsnät samt de tjänsteplattformar de används på. Rapporten kommer även granska vilken roll IMS spelar i stadsnät och varför de kan behöva en skräddarsydd IMS-lösning. Under examensarbetet byggdes och testades ett referensnätverk. Olika tjänsteplatformar testades och utvärderades.
35

Recherche sur les techniques clés pour les communications multimédias dans les Ad-Hoc réseaux

Zhou, Liang 14 April 2009 (has links) (PDF)
Dans cette thèse, nous étudions certains points techniques clé sur ce sujet et proposons une résolution pratique et efficace des aspects suivants: Dans un cadre de design inter-couche, nous avons d'abord réglé le problème du contrôle de débit et du routage. Nous étudions la combinaison de l'acheminement et le contrôle du taux avec une formulation optimisation convexe afin de proposer une solution distribuée commune basée sur la conception des inter-couche. Nous avons d'abord développé un modèle de distorsion qui couvre à la fois l'impact de la quantification du codeur et la perte de paquets en raison de la congestion du réseau sur la qualité vidéo globale. Ensuite, le contrôle du taux d'émission optimal commun et le choix du routage sont réalisés en adaptant la vitesse variable d'émission au cours du temps et en minimisant la congestion du réseau global. Ensuite, nous abordons le problème du mécanisme d'authentification du codage conjoint. Dans cette partie, nous proposons un cadre pour une collaboration entre authentification et codage multimédia transmis sur des réseaux sans fil. Premièrement, nous fournissons un système d'authentification basé sur des méthodes graphiques qui peut non seulement construire une authentification flexible, mais aussi un compromis parmi certaines exigences pratiques telles que la robustesse et le retard. Puis, un taux de distorsion conjoint Source-Canal (JSCC) est optimisé ; une approche résistante aux erreurs vidéo encodée adpatative est présentée, dans laquelle la vidéo est encodée en plusieurs flux indépendants et à chaque flux est attribué une correction (Forward Error Correction-FEC) afin d'éviter la propagation des erreurs. En outre, nous considérons l'authentification avec le régime spécifique JSCC afin de parvenir à un résultat satisfaisant en termes de qualité de reconstruction de bout en bout. Ensuite, nous proposons d'appliquer conjointement la résilience aux erreurs (ER) et la super-résolution (SR) afin d'améliorer glabalement la résolution des flux d'images transmises sur les réseaux sans fil. Afin de lutter contre la propagation d'erreurs, une description multiple, méthode flexible de codage basée sur SPIHT-3-D (partitionnement 3-D dans des arbres hiérarchiques) est présentée pour générer des descriptions variables indépendantes en fonction de l'état du réseau. Puis, une stratégie originale de protection inégale contre les erreurs suivant le niveau de priorité est prévu afin d'attribuer un niveau supérieur de protection contre les erreurs des parties les plus importantes des flux. En outre, un algorithme robuste SR est proposé, en présence de différents types de taux de perte de paquets pour améliorer la résolution de l'image. Enfin, nous décrivons le problème du contrôle du taux pour le multimédia sur des réseaux hétérogènes. Dans cette partie, nous développons et évaluons un cadre d'allocation des taux optimaux sur plusieurs réseaux hétérogènes toujours basés sur le cadre de la conception inter-couches. Au début, nous développons et évaluons un modèle de distorsion en fonction de taux disponibles observés (ABR) et du temps d'aller-retour (RTT) dans chaque réseau d'accès, ainsi que des caractéristiques de chaque application. Ensuite, la répartition du taux est formulée comme un problème d'optimisation convexe qui minimise la somme de la distorsion attendue sur tous les flux applicatifs. Afin d'obtenir une résolution satisfaisante et simple à ce problème, nous proposons un théorème d'approximation par morceaux afin de simplifier le problème convexe et de prouver la validité de la théorie. En outre, la réalisation de l'algorithme rapide heuristique pour parvenir à une répartition optimale de qualité de service ou quasi-optimale de bout en bout dans le cadre du budget global des ressources limitées est le point le plus important de cette partie de thèse. En fin de compte, un bref résumé de tous les sujets abordés dans cette thèse est donné. Les principales contributions de cette thèse sont alors rappelés.
36

Tools for static code analysis: A survey

Hellström, Patrik January 2009 (has links)
<p>This thesis has investigated what different tools for static code analysis, with anemphasis on security, there exist and which of these that possibly could be used in a project at Ericsson AB in Linköping in which a HIGA (Home IMS Gateway) is constructed. The HIGA is a residential gateway that opens up for the possibility to extend an operator’s Internet Multimedia Subsystem (IMS) all the way to the user’s home and thereby let the end user connect his/her non compliant IMS devices, such as a media server, to an IMS network.</p><p>Static analysis is the process of examining the source code of a program and in that way test a program for various weaknesses without having to actually execute it (compared to dynamic analysis such as testing).</p><p>As a complement to the regular testing, that today is being performed in the HIGA project, four different static analysis tools were evaluated to find out which one was best suited for use in the HIGA project. Two of them were open source tools and two were commercial.</p><p>All of the tools were evaluated in five different areas: documentation, installation & integration procedure, usability, performance and types of bugs found. Furthermore all of the tools were later on used to perform testing of two modules of the HIGA.</p><p>The evaluation showed many differences between the tools in all areas and not surprisingly the two open source tools turned out to be far less mature than the commercial ones. The tools that were best suited for use in the HIGA project were Fortify SCA and Flawfinder.</p><p>As far as the evaluation of the HIGA code is concerned some different bugs which could have jeopardized security and availability of the services provided by it were found.</p>
37

An IMS-based VOD Service Supporting Session Continuation

Johansson, Jonatan January 2009 (has links)
<p>IP-based TV (IPTV) is gradually replacing traditional means for broadcasting. At the same time, players from the telecom industry is seeking to create a new, standardized architectural framework for delivering all kinds of multimedia services over IP to end users; the IP Multimedia Subsystem (IMS).</p><p>This thesis is about video on demand, one of the more popular services enabled by IPTV. The thesis starts out by introducing the reader to IMS and IPTV and presents the current work in the area of IMS-based IPTV, done by the TISPAN committee of the ETSI.</p><p>The author then takes an explorative approach in investigating how a signaling schema for an IMS-based VOD service could look like, based on TISPAN’s existing work. The service is subject to an extra requirement; it should support session continuity, meaning it should be possible to resume the streaming of a video where the user left off, possibly on a different device. The investigation shows that it is possible to combine SIP and RTSP in several ways to get the desired behaviour.</p><p>The second part of the results consists of a proof of technology-implementation of the signaling schema that is the output from the first part. The implemented service runs on an IPTV set-top box on the client side, and a regular PC on the server side. The service uses open source software to a great extent and is fairly portable. A sample VOD session using the implemented system is presented along with full message contents.</p><p>The thesis concludes with a summary of the results and a discussion on what has been left out from the implementation and possibly subject to further studies. Finally, there is a brief summary on the recent developments within the field of IMS-based IPTV.</p>
38

Investigation of IMS in an IPTV context.

Gustafsson, Tobias January 2006 (has links)
<p>The trends in todays tele- and datacommunication market point toward using IP for all sorts of service delivery ranging from voice calls to TV. The next natural step in this evolution is to provide the same set of services to the end users independent of the access technology and device used. The IP Multimedia Subsystem (IMS) is an IP based telecommunications platform which targets this and lets the operators develop new services once which can then be used on many different devices.</p><p>This thesis examines the integration of IPTV and IMS. Can IMS be used to deliver TV services and can the IPTV set-top-boxes of today be used as clients in IMS? Since this is a new and previously unexamined area an explorative approach is taken. The aim is to identify how such an integration could be performed and the possible problems which have to be solved. To assist in this exploration a TV-push service based on IMS technology is constructed.</p><p>Based on the experiences from this service a general architecture for IPTV in IMS is suggested.</p><p>A number of problems crucial to solve for a successful integration are identified and possible solutions to these are discussed.</p>
39

An IMS-based VOD Service Supporting Session Continuation

Johansson, Jonatan January 2009 (has links)
IP-based TV (IPTV) is gradually replacing traditional means for broadcasting. At the same time, players from the telecom industry is seeking to create a new, standardized architectural framework for delivering all kinds of multimedia services over IP to end users; the IP Multimedia Subsystem (IMS). This thesis is about video on demand, one of the more popular services enabled by IPTV. The thesis starts out by introducing the reader to IMS and IPTV and presents the current work in the area of IMS-based IPTV, done by the TISPAN committee of the ETSI. The author then takes an explorative approach in investigating how a signaling schema for an IMS-based VOD service could look like, based on TISPAN’s existing work. The service is subject to an extra requirement; it should support session continuity, meaning it should be possible to resume the streaming of a video where the user left off, possibly on a different device. The investigation shows that it is possible to combine SIP and RTSP in several ways to get the desired behaviour. The second part of the results consists of a proof of technology-implementation of the signaling schema that is the output from the first part. The implemented service runs on an IPTV set-top box on the client side, and a regular PC on the server side. The service uses open source software to a great extent and is fairly portable. A sample VOD session using the implemented system is presented along with full message contents. The thesis concludes with a summary of the results and a discussion on what has been left out from the implementation and possibly subject to further studies. Finally, there is a brief summary on the recent developments within the field of IMS-based IPTV.
40

Investigation of IMS in an IPTV context.

Gustafsson, Tobias January 2006 (has links)
The trends in todays tele- and datacommunication market point toward using IP for all sorts of service delivery ranging from voice calls to TV. The next natural step in this evolution is to provide the same set of services to the end users independent of the access technology and device used. The IP Multimedia Subsystem (IMS) is an IP based telecommunications platform which targets this and lets the operators develop new services once which can then be used on many different devices. This thesis examines the integration of IPTV and IMS. Can IMS be used to deliver TV services and can the IPTV set-top-boxes of today be used as clients in IMS? Since this is a new and previously unexamined area an explorative approach is taken. The aim is to identify how such an integration could be performed and the possible problems which have to be solved. To assist in this exploration a TV-push service based on IMS technology is constructed. Based on the experiences from this service a general architecture for IPTV in IMS is suggested. A number of problems crucial to solve for a successful integration are identified and possible solutions to these are discussed.

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