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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.
321

Policy-based routing for mobile ad hoc networks running HTR protocol

Souza, Gabriela Coutinho Machado de 13 September 2013 (has links)
The increasing growth of mobile devices in the whole world, and the forecasts for the coming years has been indicated by several reports. Nonetheless, this need for ubiquitous collaboration has brought new possibilities and challenges to the scientific community. Mobile Ad hoc Networks (MANETs) emerges in this scenario allowing devices to interconnect autonomously, without the need of a fixed infrastructure, in order to provide communication and information services. Due to such decentralization and the natural constraints of mobile devices, it remains, to this day, a challenge to provide efficient routing for MANETs. In this dissertation we propose new routing enhancements based on policies for MANETs running the HTR protocol. We consider the role(s) a user associated to a device performs within an organization. Hence our policies can guide the routing based on these roles. With this scheme we improve communication according to different business needs and scenario requirements. To this end, we propose a set of policies that affects the routing behavior and present four case studies to present each policy. Then we analyze two policies in terms of end-to-end delay, and nodes’ lifetime. Through simulation we evaluate these metrics while varying parameters such as the amount of nodes participating in the network, the mobility characteristics, and the number of traffic sources. Our results show that it is possible to achieve these goals without causing great impact on the average end-to-end delay and energy consumption, two important metrics in any MANET evaluation. We explore the results in several scenarios and detail our findings, which can provide a different perspective for future MANET applications. / Submitted by João Arthur Martins (joao.arthur@ufpe.br) on 2015-03-10T18:42:15Z No. of bitstreams: 2 Dissertação Gabriela Coutinho.pdf: 1701782 bytes, checksum: 113328c2efdd1ba97f7a237d03cab574 (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) / Made available in DSpace on 2015-03-11T17:46:06Z (GMT). No. of bitstreams: 2 Dissertação Gabriela Coutinho.pdf: 1701782 bytes, checksum: 113328c2efdd1ba97f7a237d03cab574 (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Previous issue date: 2013-09-13 / O crescimento das vendas de aparelhos móveis em todo o mundo, bem como as previsões para os próximos anos são apontadas em diversos relatórios. No entanto, essa necessidade de colaboração ubíqua trouxe novas possibilidades e desafios para a comunidade científica. Redes móveis ad hoc (Mobile Ad hoc Networks - MANETs) surgem diante deste cenário e permite que dispositivos se comuniquem de forma autônoma, sem a necessidade de uma infraestrutura predefinida para fornecer comunicação e serviços. Porém, essa descentralização junto com as restrições naturais dos dispositivos móveis, proporcionar roteamento eficiente para MANETs permanece um desafio. Este trabalho propõe novas melhorias para o roteamento em MANETs que utilizam o protocolo HTR. Também considera o papel que usuários associados aos dispositivos desempenham dentro de uma organização. Desta forma, as políticas desenvolvidas podem guiar o roteamento também com base nestes papéis. Com este esquema, é possível melhorar a comunicação de acordo com necessidades de negócio e requerimentos de cenário. Para este fim, esta dissertação propõe um conjunto de políticas que afetam o comportamento do roteamento e analisa os impactos em termos de atraso, energia gasta e tempo de vida dos nós. Através de simulações, essas métricas são avaliadas também com variação de parâmetros como a quantidade de nós que participam da simulação, as características de mobilidade e o número de fontes de tráfego. Resultados mostram que é possível atingir esses objetivos sem causar grande impacto negativo no atraso fim a fim e no consumo de energia, duas métricas importantes em avaliações de redes MANET. Nós exploramos esses resultados em diversos cenários e detalhamos nossas descobertas, que podem servir como uma perspectiva diferente para futuras aplicações de redes MANET.
322

Les systèmes microparticulaires pour la libération colonique / Multiparticulate colon drug delivery systems

Bautzova, Tereza 17 September 2012 (has links)
La maladie de Crohn et la rectocolite hémorragique font partie des maladies inflammatoires chroniques de l'intestin (MICI). Le principal objectif des traitements anti-inflammatoires est de favoriser la délivrance du principe actif localement, spécifiquement sur les zones enflammées et de limiter les effets indésirables. Ainsi, plusieurs systèmes à libération colonique de molécules actives ont été développés. Parmi eux, les pellets présentent de nombreux avantages par rapport aux formes solides unitaires conventionnelles. Dans un premier temps, des pellets comptant une substance anti-inflammatoire naturelle et nutritive, la rutine, ont été développés. L'intérêt de cette molécule est de réduire considérablement les effets secondaires qui constituent un véritable problème dans les traitements actuels des MICI. Les pellets ont été enrobé avec les polysaccharides naturels se dégradant avec la flore colonique. Les études in vitro ont démontré une libération minimale du principe actif au niveau de l'estomac et du petit intestin. Par contre, une libération rapide et totale a été observée lors de l'exposition des pellets dans les conditions du milieu colonique. Les résultats des tests in vivo ont démontré que la rutine a atténué considérablement l'inflammation au niveau de colon et les pellets enrobés ont été aussi efficaces que les pellets d'acide 5-aminosalicylique (5-ASA) commercialisés. L'administration orale de rutine via les pellets enrobés et préparés avec le chitosan semble être une approche prometteuse, permettant la libération du principe actif au niveau des zones enflammées, pour le traitement des MICI tout en réduisant les effets secondaires. Le deuxième but de notre travail était d'élucider l'impact du chitosan, un polymère mucoadhésif, sur l'efficacité thérapeutique. Les pellets de 5-ASA ont été préparés à partir de cellulose microcristalline avec ou sans chitosan. Un enrobage constitué d'un polymère pH dépendant,1' Eudragit® FS, a ensuite été réalisé autour du noyau. Les tests de dissolution ont montré que le principe actif n'était pas libéré du pellet après 2 h en milieu acide. En revanche,la libération était rapide dans un milieu simulant l'environnement colonique. Les tests ex vivo avec les pellets contenant le chitosan ont montré des propriétés mucoadhésives importantes qui ont été confirmées par la concentration élevée du métabolite de 5-ASA dans les tissus coloniques des rats. De plus, nous avons a démontré que les pellets permettaient d'atténuer de façon significative l'inflammation du côlon. Ainsi, les pellets bioadhésifs enrobés possèdent des propriétés bénéfiques supplémentaires pour la libération du 5-ASA au niveau du côlon par rapport à des formes multidoses commercialisées pour le traitement des MICI. / Crohn's disease and ulcerative colitis are two related but distinct chronic inflammatory disorders of gastrointestinal tract (GIT), commonly denoted as inflammatory bowel disease(IBD). The main goal of the anti-inflammatory treatment of this disorder is to achieve maximal drug concentration in inflamed area and reduce systemic adverse effects. For this purpose several colon-spécifie drug delivery systems have been investigated. In addition, the design of pellets as oral drug delivery systems may provide many advantages over single unit preparations and thus improve patient compliance. It is well known that most existing treatments of IBD are associated with significant side effects and for this reason the formulation with a " food like " composition was designed. In the first part of our study, therapeutic efficiency of rutin/chitosan pellets with coatings based on natural polysaccharides degraded by colonie microbiota compared to commercialized 5-aminosalicylic acid (5-ASA) pellets was investigated. Release profiles ofcoated pellets showed a minimal drug release in simulated stomach and small intestine following by rapid drug release upon exposure to the colonie fluid. The results from in vivo testing showed that rutin attenuated efficiently inflammation in the colon and coated pellets were as effective as 5-ASA pellets in mitigating experimental colitis. The studies demonstrated that rutin administration via chitosan core coated pellets seems to be apromising approach for colon-specific delivery since they could interact easily with the mucin layer and deliver drug especially to the inflamed colonie area to relieve symptoms of IBD omitting side effects related to conventional treatment. The second objective of this thesis was to explore the impact of additional mucoadhesive polymer chitosan in the pellets core on the therapeutic efficiency. For this purpose, 5-ASA loaded pellets were produced by extrusion/spheronisation method and subsequently coated with pH-sensitive polymer Eudragit® FS. No drug release at pH 1.2within 2 h, and release as intended in the simulated distal ileum and colon was observed. Chitosan-core pellets showed efficient mucoadhesive properties in ex vivo bioadhesion testing which were also confirmed by increased concentration of 5-ASA metabolite in the colonie tissues in rats. The pellets were tested in preexisting colitis and the results revealed significant attenuation of the colonie inflammation. We can conclude, that bioadhesive chitosan-corepellets showed additional beneficial properties for colonie 5-ASA delivery in the treatment of IBD over marketed dosage formulation.
323

Conception d'une plate-forme multi-échelle hybride pour évaluer les performances de systèmes orientés internet des objets / Designing multiscale hybrid platform for testing and evaluationg IoT systems

Abu Oun, Osama 09 October 2015 (has links)
Les chercheurs au travers de plusieurs domaines essaient de fournir des solutions pour intégrer les objets et les systèmes dans l’internet des objets (IdO ou IoT pour Internet of Things en anglais). Il y a deux domaines parmi les domaines les plus importants d’IdO. Le premier est de tester et évaluer l’IdO. Plusieurs milliards d’objets sont déjà connectés à l’internet. Ces objets peuvent communiquer entre eux directement sans intervention humaine. Les entreprises et les développeurs doivent être capable de tester et d’évaluer des scénarios différents dans plusieurs environnements. Ces environnements doivent être capable d’échanger des services entre eux. Nous présentons notre architecture IoTaaS (Internet of Things Testing As A Service). IoTaaS est un environnement distribué pour tester et évaluer l’IdO. Nous présentons aussi la première mise en oeuvre expérimentale qui est appelée CEMAT (Cloud Environment for Mobile Application Testing) qui permet de tester les applications mobiles et les objets connectés. Le deuxième domaine correspond aux méthodes de communication. Nous présentons notre conception de communications COLDE (Connectionless Data Exchange) pour échanger une petite quantité de données publiques entre les clients Wi-Fi et les points d’accès sans qu’ils aient besoin d’être associés. Alors que COLDE présente la méthode nécessaire pour échanger ces données, le concept de services Lightweight décrit les données échangées en utilisant le protocole COLDE. / Researchers across many domains are working to provide solutions that enable integration of objectsand systems into the Internet of Things (IoT). There are two domains which are among the mostimportant ones in IoT. First domain is IoT testing and evaluation. The billions of objects whichare connected to IoT would intercommunicate without any human intervention. Enterprises anddevelopers should be able to test and evaluate different operational scenarios of their systems indifferent environments. Testing environments should be able to exchange services. We present ourarchitecture IoTaaS (Internet of Things Testing As A Service). IoTaaS is a hierarchy of a distributedcloud for testing and evaluating IoT. We also present the pilot implementation of IoTaaS under thecode name CEMAT (Cloud Environment for Mobile Application Testing) which focuses on mobiledevices and their connected objects. The second domain is about communication methods andtechniques. Several IoT applications depend on public data exchange. We present our design toexchange small amount of public data on wireless network without establishing a connection. COLDE(Connectionless Data Exchange) is our extension to protocol the IEEE 802.11. COLDE utilizesthe management frames to allow Wi-Fi devices and access points to exchange small amounts ofdata without having any association. COLDE describes how we can exchange data without beingconnected. Lightweight services concept explains which data could be transferred using COLDE.Simulation experiments and real world implementation are presented along with their results.
324

Integrating environmental data acquisition and low cost Wi-Fi data communication.

Gurung, Sanjaya 12 1900 (has links)
This thesis describes environmental data collection and transmission from the field to a server using Wi-Fi. Also discussed are components, radio wave propagation, received power calculations, and throughput tests. Measured receive power resulted close to calculated and simulated values. Throughput tests resulted satisfactory. The thesis provides detailed systematic procedures for Wi-Fi radio link setup and techniques to optimize the quality of a radio link.
325

Role of Immunity-Related GTPases (IRGs) for maintaining virulent Toxoplasma gondii in wild rodents

Torelli, Francesca 24 April 2020 (has links)
Toxoplasma gondii ist ein weltweit verbreiteter Parasit. In Europa ernährt sich der Endwirt (Katzen) hauptsächlich von kleinen Säugetieren wie Myodes glareolus und Microtus spp. (Wühlmäusen) und Apodemus spp., seltener von Mus spp. Erstere zeigen gegenüber Mus spp. erhöhte Prävalenzen von T. gondii und überleben diese eher als Mus spp. Daher wird vermutet, dass Wühlmäusen und Apodemus spp. eine größere Rolle als Zwischenwirte besitzen, als Mus spp. Der Schutz wird auf das IFN-γ-induzierte IRGb2-b1 zurückgeführt, die den zentralen parasitären Virulenzfaktor ROP5 inhibiert. Daher liegt der Fokus meiner Arbeit auf der protektiven Rolle von IRGb2-b1 bei der Infektion mit T. gondii in Wühlmäusen und Apodemus spp. Mit dieser Arbeit trage ich nützliche Werkzeuge zur Erforschung von Wühlmäusen bei, wie ein rekombinantes M. glareolus IFN-γ Zytokin und neuartige Zellsysteme. Alle untersuchten Wühlmaus-Systeme besaßen einen Phänotyp bei Infektion mit in vivo Resistenz beschrieben wurde: einem IFN-γ-vermittelten Reduktion der Parasitenbürde (mit Wirtszelltod für Typ I Parasiten, ohne für Typ II). Darüber hinaus bestätigen vorläufige Resultate aus Wühlmäusen und Apodemus spp. in Deutschland hohe genetische Vielfalt der IRGb2 Untereinheit zeigen, insbesondere an der vermuteten Grenzfläche zum ROP5, was auf eine Rolle dieses Proteins bei der Infektion hindeutet. Um die Funktion der IRGb2-b1 Proteine zu untersuchen, habe ich ein Zellkultur System, entwickelt, welches erlaubt wild-derived Gene stabil zu exprimieren. Dieses Setup gestattet es, die Auswirkungen von Polymorphismen in Irg Genen bei der Infektion mit T. gondii zu evaluieren. Insgesamt habe ich Werkzeuge erarbeitet, um den Ansatz der Öko-Immunologie in eine Labor-Umwelt zu bringen, wodurch die molekulare Untersuchung ökologisch relevanter Arten möglich wird. Durch Anwendung dieser Werkzeuge stütze ich die Hypothese, dass nicht-Mus Nagetiere, insbesondere M. glareolus, ein bedeutendes Reservoir für T. gondii darstellen. / Toxoplasma gondii is an ubiquitous parasite grouped in three main clonal lineages, type I-III. In Europe, felids, definitive hosts for the parasite, mostly prey on small mammals of Myodes glareolus and Microtus spp. (voles), and Apodemus spp., rather than Mus spp. Voles and Apodemus spp. also display higher T. gondii prevalence and survive infection to a larger extent than Mus spp., although tolerant Mus subspecies exist. This suggests that voles and Apodemus spp. are more relevant intermediate hosts than Mus spp.. Resistance to infection relies on the IFN-γ-induced IRGb2-b1, which inhibits the major parasite virulence factor ROP5. Thus, this work focuses on the protective role of IRGb2-b1 during T. gondii infection in voles and Apodemus spp. With this project I contribute with valuable tools for research on voles, such as the supply of the recombinant M. glareolus IFN-γ cytokine and novel cell systems. All vole systems show a phenotype to type I infection which is associated with in vivo resistance in Mus spp: IFN-γ-mediated host cell death and a decrease in parasite burden. The latter without cell death was observed for type II parasites, suggesting novel protective mechanisms. Further, preliminary results from voles and Apodemus spp. in Germany confirm the expected high diversity in the IRGb2-like subunit, especially at the putative interface with ROP5, which suggests a role of the protein during infection. To assess the role of IRGb2-b1-like in this phenotype, I developed a system which allows establishment of cell lines stably expressing wild-derived Irg-like genes. This setup allows evaluation of the effect of polymorphisms of Irg-like genes during infection. Taken together, I have provided tools to bring eco-immunology into a lab setting to perform molecular investigations of ecologically relevant species. Using these tools, I offer support for the hypothesis that non-Mus rodents, especially M. glareolus, constitutes a relevant T. gondii reservoir in Germany.
326

Model fyzické vrstvy komunikačního systému IEEE 802.11ah / Model of physical layer of communication system IEEE 802.11ah

Jurák, Petr January 2018 (has links)
This diploma thesis deals with the analysis of the IEEE 802.11ah wireless communication system. For such a purpose, an appropriate simulation model in program environment MATLAB is created. The first part of thesis focuses on the IEEE 802.11 standard. Basic blocks of the transmitter and receiver are described. Attention is also devoted on the brief description of considered transmission channels. The second part contains the description of the proposed and realized simulation model in MATLAB. Individual blocks of the simulation model are described in details. Finally, the obtained simulation results are evaluated and discussed.
327

Zařízení pro záznam dat / Data logger

Dráb, Dominik January 2018 (has links)
This master's thesis deals with design of universal data logging device. The work proposes the design of device architecture and describes individual systems and components, that are necessary for data logging. Logger is designed as a mobile device, with ARM microcontroller at its core. Thesis specifies requirements for device in terms of performance and versatility. The device uses modular construction, as it comprises multiple PCBs. The thesis describes their design and also design of the mechanical construction of data logger. Designed device has been realized and assembled. Software design for microcontroller is also part of the thesis. In the last part, measurements to determine achieved parameters of the device are conducted.
328

Robotická ruka / Robotic hand

Pizúr, Lukáš January 2019 (has links)
The aim of this work is to design a robotic hand, which will be controlled by wireless Wi-Fi, will be equipped with a camera and for easier operation will be designed control glove. The first part of the thesis is a theoretical analysis, various variants of sensors are described, which can be used for motion detection, each drive units and their control. Next chapters are focused on used electronic modules and microcontrollers. The second part is practical and is focused on the mechanical design of a five-finger robotic hand and fixing to a robotic arm. Also described is the control electronics of the entire robotic hand and the programmed firmware. Next, the design and implementation of the control glove is described. The last chapter describes the programmed application for the Android operating system.
329

Koexistence systémů LoRa a Wi-Fi v RF pásmu 2.4 GHz / Coexistence of LoRa and Wi-Fi in the RF band 2.4 GHz

Kaučiarik, Filip January 2020 (has links)
Diplomová práca sa zaoberá štúdiom koexistencie, ktorá môže nastať medzi bezdrôtovými komunikačnými systémami LoRa a Wi-Fi v bezlicenčnom ISM pásme 2,4 GHz. V teoretickej časti práce sú stručne popísané fyzické vrstvy obidvoch systémov. Následne sú definované spoločné frekvenčné pásma a koexistenčné scenáre, ktoré môžu vzniknúť medzi uvažovanými systémami v spoločnom rádiofrekvenčnom (RF) pásme. V experimentálnej časti práce je prezentované laboratórne meracie pracovisko, ktoré bolo navrhnuté na meranie rôznych koexistenčných scenárov medzi technológiou LoRa a Wi-Fi. Funkčnosť navrhnutej koncepcie je overená experimentálnym meraním. Výsledky meraní sú detailne komentované a prezentované. Je navrhnutá laboratórna úloha a vzorový protokol pre vzdelávacie účely v Laboratóriu Mobilných a Bezdrôtových komunikácií.
330

Chytré digitální zrcadlo pro individuální sporty / Smart Digital Mirror for Individual Sports

Opichal, Tomáš January 2021 (has links)
The aim of this diploma thesis is to create a practical solution for individual athletes in the form of a digital mirror, which can become an alternative to observing yourself in an ordinary mirror. The work contains and emphasizes the benefits of a digital mirror. Much of the work is devoted to the transfer of video between various devices for the ability to combine multiple videos on a single screen. The core of the solution is a mobile application for the Android platform, which works in various modes, the choice of which depends on how the application is used. The application was continuously tested with a group of users, resulting in iterative improvements to the application's features and the addition of new features. Furthermore, a web variant of the application was implemented, which increases the possibility of using the digital mirror across different platforms. The results of testing show that this whole solution can be used in the practical training of sports exercises and the application has the potential to connect with various sports.

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