Um dos principais desafios em Redes Centradas em Informação (ICN) é como prover controle de acesso à publicação e recuperação de conteúdos. Apesar das potencialidades, as soluções existentes, geralmente, consideram um único usuário agindo como publicador. Ao lidar com múltiplos publicadores, elas podem levar a uma explosão combinatória de chaves criptográficas. As soluções projetadas visando a múltiplos publicadores, por sua vez, dependem de arquiteturas de redes específicas e/ou de mudanças nessas para operar. Nesta dissertação é proposta uma solução, apoiada em criptografia baseada em atributos, para controle de acesso a conteúdos. Nessa solução, o modelo de segurança é voltado a grupos de compartilhamento seguro, nos quais todos os usuários membros podem publicar e consumir conteúdos. Diferente de trabalhos anteriores, a solução proposta mantém o número de chaves proporcional ao de membros nos grupos e pode ser empregada em qualquer arquitetura ICN de forma gradual. A proposta é avaliada quanto ao custo de operação, à quantidade de chaves necessárias e à eficiência na disseminação de conteúdos. Em comparação às soluções existentes, ela oferece maior flexibilidade no controle de acesso, sem aumentar a complexidade do gerenciamento de chaves e sem causar sobrecustos significativos à rede. / One of the main challenges in Information-Centric Networking (ICN) is providing access control to content publication and retrieval. In spite of the potentialities, existing solutions often consider a single user acting as publisher. When dealing with multiple publishers, they may lead to a combinatorial explosion of cryptographic keys. Those solutions that focus on multiple publishers, on the other hand, rely on specific network architectures and/or changes to operate. In this dissertation, it is proposed a solution, supported by attribute-based encryption, for content access control. In this solution, the security model is focused on secure content distribution groups, in which any member user can publish to and retrieve from. Unlike previous work, the proposed solution keeps the number of cryptographic keys proportional to the number of group members, and may even be adopted gradually in any ICN architecture. The proposed solution is evaluated with respect to the overhead it imposes, number of required keys, and efficiency in the content dissemination. In contrast to existing solutions, it offers higher access control flexibility, without increasing key management process complexity and without causing significant network overhead.

This thesis provides novel contribution to the field of body-centric wireless communications (BCWC) with the development of a measurement methodology for wearable antenna characterisation on the human body, the implementation of fully-textile wearable antennas and the on-body channel modelling considering different antenna types and user's dynamic effects. More specifically, a measurement methodology is developed for characterising wearable antennas on different locations of the human body. A cylindrical near-field (CNF) technique is employed, which facilitates wearable antenna measurements on a full-body solid anthropomorphic mannequin (SAM) phantom. This technique allows the fast extraction of the full spherical radiation pattern and the corresponding radiation efficiency, which is an important parameter for optimising wearable system design. It appears as a cost- effective and easy to implement solution that does not require expensive positioning systems to rotate the phantom, in contrast to conventional roll-over-azimuth far-field systems. Furthermore, a flexible fully-textile wearable antenna is designed, fabricated and measured at 2.4 GHz that can be easily integrated in smart clothing. It supports surface wave propagation and exhibits an omni-directional radiation pattern that makes it suitable for on-body communications. It is based on a multilayer low-profile higher-mode patch antenna (HMMPA) design with embroidered shorting vias. Emphasis is given to the fabrication process of the textile vias with conductive sewing thread that play an important role in generating the optimal mode for on-body radiation. The radiation pattern shape of the proposed fully-textile antenna was found to be similar to a copper rigid antenna, exhibiting a high on-body radiation efficiency of 50 %. The potential of the embroidery technique for creating wearable antennas is also demonstrated with the fabrication of a circularly polarised spiral antenna that achieves a broadband performance from 0.9-3 GHz, which is suitable for off-body communications. By testing the textile spiral antenna on the SAM phantom, the antenna-body interaction is examined in a wide frequency range. Finally, a statistical characterisation of on-body communication channels is undertaken both with EM simulations and channel measurements including user's dynamic movement (walking and running). By using antenna types of different polarisation, the on-body channels are examined for different propagation conditions. Four on-body channels are examined with the one part fixed on the waist of the human body while the other part located on the chest, back, wrist and foot. Channel path gain is derived, while large-scale and small-scale fading are modelled by best-fit statistical distributions.

Um dos principais desafios em Redes Centradas em Informação (ICN) é como prover controle de acesso à publicação e recuperação de conteúdos. Apesar das potencialidades, as soluções existentes, geralmente, consideram um único usuário agindo como publicador. Ao lidar com múltiplos publicadores, elas podem levar a uma explosão combinatória de chaves criptográficas. As soluções projetadas visando a múltiplos publicadores, por sua vez, dependem de arquiteturas de redes específicas e/ou de mudanças nessas para operar. Nesta dissertação é proposta uma solução, apoiada em criptografia baseada em atributos, para controle de acesso a conteúdos. Nessa solução, o modelo de segurança é voltado a grupos de compartilhamento seguro, nos quais todos os usuários membros podem publicar e consumir conteúdos. Diferente de trabalhos anteriores, a solução proposta mantém o número de chaves proporcional ao de membros nos grupos e pode ser empregada em qualquer arquitetura ICN de forma gradual. A proposta é avaliada quanto ao custo de operação, à quantidade de chaves necessárias e à eficiência na disseminação de conteúdos. Em comparação às soluções existentes, ela oferece maior flexibilidade no controle de acesso, sem aumentar a complexidade do gerenciamento de chaves e sem causar sobrecustos significativos à rede. / One of the main challenges in Information-Centric Networking (ICN) is providing access control to content publication and retrieval. In spite of the potentialities, existing solutions often consider a single user acting as publisher. When dealing with multiple publishers, they may lead to a combinatorial explosion of cryptographic keys. Those solutions that focus on multiple publishers, on the other hand, rely on specific network architectures and/or changes to operate. In this dissertation, it is proposed a solution, supported by attribute-based encryption, for content access control. In this solution, the security model is focused on secure content distribution groups, in which any member user can publish to and retrieve from. Unlike previous work, the proposed solution keeps the number of cryptographic keys proportional to the number of group members, and may even be adopted gradually in any ICN architecture. The proposed solution is evaluated with respect to the overhead it imposes, number of required keys, and efficiency in the content dissemination. In contrast to existing solutions, it offers higher access control flexibility, without increasing key management process complexity and without causing significant network overhead.

abstract: This study examined the processes of academic advisement in a school-centric university environment utilizing the O'Banion Model of Academic Advising (1972) as a baseline for theoretical comparison. The primary research question sought to explore if the O'Banion Model of Academic Advising, a dominant theory of advisement processes, was still representative of and present in contemporary advisement. A qualitative case study methodology was utilized to explore the lived experiences of professional staff academic advisors in the academic advisement process. Eleven professional staff advisors were interviewed for up to 90 minutes each about their lived experience in providing academic advisement services. A structured series of questions were asked about the academic advisors' experiences with the process and their daily advisement activities. The participants were asked how the vision, mission, philosophies, and structures of the institution impacted their role and responsibilities in the advisement process. Mixed results were found over the presence of the O'Banion Model in contemporary advisement. The results revealed significant additional workloads, unique structures, and complex roles as a result of the institution's school-centric philosophy. Role ambiguity and confusion over responsibility for the advisement process were found. / Dissertation/Thesis / Ed.D. Higher and Postsecondary Education 2014

A cirurgia ortognática é uma modalidade terapêutica que vem se tornando cada vez mais comum ao cotidiano de cirurgiões bucomaxilofaciais e ortodontistas. Os dados presentes na literatura quanto a variabilidade do posicionamento mandibular em indivíduos com discrepâncias maxilomandibulares são escassos, fruto de poucas pesquisas ou somente refletem opinião de autores. O presente estudo objetivou a avaliação da variabilidade no posicionamento mandibular entre diferentes registros oclusais e o entendimento da influência das variáveis faixa etária, gênero, tipo de deformidade ou tipo de cirurgia aos resultados. Utilizando amostra composta por 30 indivíduos com deformidade dentofacial a serem submetidos a cirurgia ortognática, estudamos o registro da oclusão dental obtido em três diferentes situações: relação cêntrica, máxima intercuspidação e sob anestesia geral. Tais referências oclusais foram utilizadas para montagem de modelos mandibulares de gesso em articulador semi-ajustável e três pontos dentais (um anterior, um posterior direito e um posterior esquerdo) foram utilizados para determinar possível variação da posição mandibular. Os resultados indicaram tendência geral, com significância estatística, para recuo da mandíbula quando comparamos sua mudança de posição de máxima intercuspidação para relação cêntrica, não havendo significância estatística para a posição mandibular sob anestesia geral quando comparada à posição em relação cêntrica. Faixa etária e tipo de deformidade demonstraram-se como variáveis de influência significante aos resultados. / Orthognathic surgery is a surgical therapeutical modality that has become more common among oral and maxillofacial surgeons and orthodontists. Current data regarding variability of mandibular positioning are scarce, mainly the result of few researches or author`s opinions. The present study aimed the evaluation of the variability of mandibular positioning among different occlusal registrations and the knowledge of whether age, gender, type of deformity or type of proposed surgery would influence results. Through a sample of 30 subjects with dentofacial deformities to be submitted to orthognathic surgery, dental occlusion registrations in three different situations were evaluated: centric relation, maximum intercuspation and under general anesthesia. Such registrations were used to mount cast models on semi-adjustable articulators and three dental points (one anterior, one posterior to the right and one posterior to the left) were used to determine possible variation of the mandibular position. Results indicated overall tendency with statistical significance for mandibular retrusion of the mandible when its position in maximum intercuspation is compared with centric relation, not presenting statistical significance for the mandible position under general anesthesia when compared to centric relation. Age and type of deformity did represent themselves as variables of influence to the results.

No description available.

Our modern information society provides us with a tremendous amount of information. Several issues have surfaced due to the complexity inherent in the handling of the information systems. One of the most important issues is that of providing an architecture and methodology that provide for the development and maintenance of complex, distributed information systems. As the information flow and quantity hinders us from having qualitative information when needed, the architecture must address the reach, richness and value of the information. Network-centric warfare is a problem domain that has been initiated to meet the power of information. To be able to support such continouos sustainability, a robust network infrastructure is critical. A systemic perspective on network-centric environments as well as a technical perspective on network-centric environment shows that, although promising, contemporary implementations having a service-oriented architecture lack support for physical scalability and a cognitive decoupling that would provide for multiple users acting on the same environment. Consequently, a service-oriented layered architecture for communicating entities is presented where these issues are addressed. For verification, a demonstrator is developed upon a service-oriented layered architecture for communicating based on a network-centric warfare scenario.

This dissertation discusses a software application development framework. The framework supports developing software applications within the context of Joint Command and Control, which includes interoperability with network-centric systems as well as interoperability with existing legacy systems. The next generation of Command and Control systems are expected to be built on common architectures or enterprise middleware. Enterprise middleware does however not directly address integration with legacy Command and Control systems nor does it address integration with existing and future tactical systems like fighter aircraft. The software framework discussed in this dissertation enables existing legacy systems and tactical systems to interoperate with each other; it enables interoperability with the Command and Control enterprise; and it also enables simulated systems to be deployed within a real environment. The framework does all of this through a unique distributed architecture. The architecture supports both system interoperability and the simulation of systems and equipment within the context of Command and Control. This hybrid approach is the key to the success of the framework. There is a strong focus on the quality of the framework and the current implementation has already been successfully applied within the Command and Control environment. The current framework implementation is also supplied on a DVD with this dissertation. / Dissertation (MEng)--University of Pretoria, 2011. / Electrical, Electronic and Computer Engineering / unrestricted

Les réseaux centrés contenus (ICN) sont considérés comme une solution aux nouveaux défis et modes de communication liés à l'émergence de l'Internet des Objets (IoT). Pour confirmer cette hypothèse, la problématique fondamentale du routage sur les réseaux ICN-IoT doit être abordée. Cette thèse traite de ce sujet à travers l'architecture IoT.Premièrement, une méthode sécurisée est introduite pour acheminer des paquets ICN à partir de coordonnées géographiques dans un réseau sans-fil de capteurs à faible puissance. Elle est comparée à une inondation optimisée du réseau inspirée des approches existant dans la littérature. En particulier, leur faisabilité et passage à l'échelle sont évalués via un modèle mathématique. Le modèle est paramétré grâce à des données réalistes issues de simulation, de la littérature, et d'expériences sur des capteurs. Il est montré que le routage géographique permet de diviser la mémoire nécessaire sur les capteurs par deux et de réduire considérablement le coût énergétique du routage, en particulier pour des topologies dynamiques.Ensuite, ICN est utilisé pour contrôler l'admission à une plate-forme de calcul de type Fog afin de garantir le temps de réponse. La stratégie de contrôle d'admission proposée, le LRU-AC, utilise l'algorithme Least-Recently-Used (LRU) pour apprendre en direct la distribution de popularité des requêtes. Son efficacité est démontrée grâce à un modèle fondé sur un réseau de files d'attente. Une implémentation du LRU-AC est proposé, utilisant des filtres de Bloom pour satisfaire aux contraintes des cartes FPGA. Son bien-fondé est prouvé par un modèle mathématique et son efficacité en termes de latence et débit démontrée.Enfin, on présente vICN, un outil pour la gestion et la virtualisation de réseaux ICN-IoT. Il s'agit d'une plate-forme qui unifie la configuration et la gestion des réseaux et des applications en exploitant les progrès des techniques d'isolation et de virtualisation. vICN est flexible, passe à l'échelle, et peut remplir différents buts : expériences à grande échelle reproductibles pour la recherche, démonstrations mélangeant machines émulées et physiques, et déploiements réels des technologies ICN dans les réseaux IP existants. / As the Internet of Things (IoT) has brought upon new communication patterns and challenges, Information-Centric Networking (ICN) has been touted as a potential solution. To confirm that hypothesis, the fundamental issue of routing and forwarding in the ICN-IoT must be addressed. This thesis investigates this topic across the IoT architecture.First, a scheme to securely forward ICN interests packets based on geographic coordinates is proposed for low-power wireless sensor networks (WSN). Its efficiency is compared to an optimized flooding-based scheme similar to current ICN-WSN approaches in terms of deployability and scalability using an analytical model. Realistic data for the model is derived from a mixture of simulation, literature study, and experiments on state-of-the-art sensor boards. Geographic forwarding is shown to halve the memory footprint of the ICN stack on reference deployments and to yield significant energy savings, especially for dynamic topologies. Second, ICN is used to enhance admission control (AC) to fixed-capacity Edge-computing platforms to guarantee request-completion time for latency-constrained applications. The LRU-AC, a request-aware AC strategy based on online learning of the request popularity distribution through a Least-Recently-Used (LRU) filter, is proposed. Using a queueing model, the LRU-AC is shown to decrease the number of requests that must be offloaded to the Cloud. An implementation of the LRU-AC on FPGA hardware is then proposed, using Ageing Bloom Filters (ABF) to provide a compact memory representation. The validity of using ABFs for the LRU-AC is proven through analytical modelling. The implementation provides high throughput and low latency.Finally, the management and virtualization of ICN-IoT networks are considered.vICN (virtualized ICN), a unified intent-based framework for network configuration and management that uses recent progress in resource isolation and virtualization techniques is introduced. It offers a single, flexible and scalable platform to serve different purposes, ranging from reproducible large-scale research experimentation to demonstrations with emulated and/or physical devices and network resources and to real deployments of ICN in existing IP networks.

京都大学 / 新制・課程博士 / 博士(情報学) / 甲第23438号 / 情博第768号 / 新制||情||131(附属図書館) / 京都大学大学院情報学研究科知能情報学専攻 / (主査)教授 黒橋 禎夫, 教授 河原 達也, 教授 伊藤 孝行 / 学位規則第4条第1項該当 / Doctor of Informatics / Kyoto University / DFAM