Due to an exponentially larger address space than Internet Protocol version 4 (IPv4), the Internet Protocol version 6 (IPv6) uses new methods to assign network addresses to Internet nodes. StateLess Address Auto Configuration (SLAAC) creates an address using a static value derived from the Media Access Control (MAC) address of a network interface as host portion, or interface identifier (IID). The Dynamic Host Configuration Protocol version 6 (DHCPv6) uses a client-server model to manage network addresses, providing stateful address configuration. While DHCPv6 can be configured to assign randomly distributed addresses, the DHCP Unique Identifier (DUID) was designed to remain static for clients as they move between different DHCPv6 subnets and networks. Both the IID and DUID are static values which are publicly exposed, creating a privacy and security threat for users and nodes. The static IID and DUID allow attackers to violate unsuspecting IPv6 users' privacy and security with ease. These static identifiers make geographic tracking and network traffic correlation over multiple sessions simple. Also, different classes of computer and network attacks, such as system-specific attacks and Denial-of-Service (DoS) attacks, are easier to successfully employ due to these identifiers. This research identifies and tests the validity of the privacy and security threat of static IIDs and DUIDs. Solutions which mitigate or eliminate the threat posed by static identifiers in IPv6 are identified. / Master of Science

No description available.

The current Internet routing and addressing architecture is facing a serious scalability problem. The default free zone (DFZ) routing table size grows at an increasing and potentially alarming rate. The Internet architecture uses a single namespace - the IP address, to express two functions about a network entity: its identifier and locator. This overloading of semantics leads to the scalability problem as a consequence of multihoming, traffic engineering, and nonaggregatable address allocations. The current Internet architecture does not inherently support emerging features such as mobility either. This thesis presents a simple addressing and forwarding architecture (SAFA) for the Internet. SAFA separates the locator namespace from the ID namespace so that the locators can follow the hierarchies in the Internet topology and be aggregated. The locators are allocated dynamically and automatically. The hierarchical format of locators gives end systems more control over the route selection. A straightforward forwarding scheme is designed based on the hierarchical addressing scheme. The meshed part of the Internet topology is integrated into the forwarding procedure through a special forwarding table. With a rendezvous service that maps from IDs to locators, SAFA also provides scalable support for mobility, multihoming and traffic engineering. Our work also includes an Internet topology study and a prototype implementation of the architecture. The evaluation results suggest that SAFA would be feasible in the current Internet if deployed.

The current Internet routing and addressing architecture is facing a serious scalability problem. The default free zone (DFZ) routing table size grows at an increasing and potentially alarming rate. The Internet architecture uses a single namespace - the IP address, to express two functions about a network entity: its identifier and locator. This overloading of semantics leads to the scalability problem as a consequence of multihoming, traffic engineering, and nonaggregatable address allocations. The current Internet architecture does not inherently support emerging features such as mobility either. This thesis presents a simple addressing and forwarding architecture (SAFA) for the Internet. SAFA separates the locator namespace from the ID namespace so that the locators can follow the hierarchies in the Internet topology and be aggregated. The locators are allocated dynamically and automatically. The hierarchical format of locators gives end systems more control over the route selection. A straightforward forwarding scheme is designed based on the hierarchical addressing scheme. The meshed part of the Internet topology is integrated into the forwarding procedure through a special forwarding table. With a rendezvous service that maps from IDs to locators, SAFA also provides scalable support for mobility, multihoming and traffic engineering. Our work also includes an Internet topology study and a prototype implementation of the architecture. The evaluation results suggest that SAFA would be feasible in the current Internet if deployed.

The presented thesis handles the theme of the addressing in European Portuguese. It is started with the critics of the existing terminology and in order to express the complexity of the current reality in the studied language more clearly, the author introduces the term of the allocution form which includes the addressing with pronouns (i.e. tu used with 2SG, você - 3SG, vós - 2PL and vocês - 3PL), as well as with the titles (e.g. o senhor / a senhora (Mr/Mrs) with variants combined with further titles and name/surname). It is worth to add that the work focuses on the indirect (or subjective) addressing (i.e. integrated into the phrase structure). The starting point of the own research is the theoretical basis comprising both external (Czech manuals, French vision by TEYSSIER 1989) and internal (based on Portuguese Grammars and studies) views of the issue. The research itself is inspired by author's personal language experience and the incertitude of the mother tongue speakers. The research method was realized by two questionnaires. The first of them (D1) gained 21 respondents coming from the academic ambient of Porto. The 2nd one (D2) covers a significantly larger amount of participants (202) as well as a wider socio-demographic and geographical structure (people of different professions from all...

Este trabalho se propõe a analisar a construção do endereçamento nos textos de alunos do primeiro ano do ensino médio de uma escola da rede pública de ensino. O conceito de endereçamento que se toma é o de Bakhtin (2011), segundo o qual o endereçamento é o traço constitutivo e fundamental de todo enunciado. A concepção de escrita e enunciado que subsidiam nosso estudo se fundamenta em uma perspectiva enunciativo-discursiva que tem respaldo nos estudos de Pêcheux (1969, 1975, 2002), Voloshinov/Bakhtin (1926, 1930); entendendo a escrita não apenas como registro ou tecnologia, mas como um modo de enunciação (CORRÊA, 2013). A hipótese levantada é a de que os textos produzidos pelos alunos na esfera escolar apresentam múltiplo endereçamento, isto é, além do endereçamento previsto pelo gênero discursivo proposto, apresentam outros não previstos. A metodologia que orientou a percepção do múltiplo endereçamento foi a de uma perspectiva etnográfico-discursiva (CORRÊA, 2011) de observação dos dados aliada ao paradigma indiciário proposto por Ginzburg (1989) como um modelo epistemológico adequado para pesquisas no campo das ciências humanas. O procedimento quanto à determinação dos indícios foi a busca por marcas de dialogia presente nas rupturas da interlocução prevista pelo gênero a partir das quais foi possível perceber o múltiplo endereçamento do texto. A análise possibilitou a caracterização de dois tipos de endereçamento: um previsto pelo gênero discursivo, nomeado de endereçamento transparente e outro, mais difuso, da ordem do discurso, nomeado de endereçamento opaco. Para explicitação do endereçamento opaco, buscou-se pelas rupturas genéricas, argumentativas e de voz presentes nos textos. Além do endereçamento ao destinatário previsto pelo gênero, contatou-se o endereçamento ao professor, como um destinatário sempre representado, além de outros interlocutores como colegas de classe, professores de outras disciplinas, a família, a escola como instituição. Tal constatação lança luz sobre problemas textuais, comumente interpretados como inadequação ou erro, defendendo a compreensão dessas inadequações como decorrentes do processo enunciativo-discursivo pelo qual o escrevente se insere na escrita. / This doctoral thesis aims to analyze the construction of addressing in the texts of students of the first year of high school in a public school. The concept of addressing is that of Bakhtin (2011), according to whom addressing is the constitutive and fundamental feature of every statement. The conception of writing and statement that support our study is based on an enunciative-discursive perspective that has support in the studies of Pêcheux (1969, 1975, 2002), Voloshinov/Bakhtin (1926, 1930), understanding writing not only as a record or technology, but as a mode of enunciation (CORRÊA, 2013). The hypothesis raised is that the texts produced by the students in scholar sphere have a multiple addressing, that is, besides the addressing provided by the proposed discursive genre, there are other unanticipated addresses that can be observed in the statement discursive materiality. The methodology that guided the perception of multiple addressing was that of an ethnographic-discursive perspective (CORRÊA, 2011) of observation of data allied to the indicial paradigm proposed by Ginzburg (1989) as an adequate epistemological model for research in human sciences. The hypothesis that guided the search for the clues was the dialogue and the ruptures were considered the indications from which it was possible to perceive the multiple addressing of the text. The analysis of the texts allowed the characterization of two types of addressing: one predicted by the discursive genre named transparent addressing and the other more diffuse, since it is of the order of discourse, called opaque addressing. In order to explain the opaque addressing, it was searched for generic, argumentative and voice ruptures of the text. It could be noticed that these ruptures were related, many being effect of displacements of the address of the text. Therefore, multiple address could be attested, since it was detected in the analyzed texts, besides the intended genre addressing, also the teacher as an addressing always represented, as well as others such as classmates, teachers of other disciplines, the family, the school as an institution. This finding sheds light on textual problems, commonly interpreted as inadequacy or error, pointing to their understanding as arising from the enunciative-discourse process that the scribe is inserted into when they are writing.

<p>Among the various physical systems considered for scalable quantum information processing (QIP), individually trapped ions or neutral atoms have emerged as promising candidates. Recent experiments using these systems have demonstrated the basic building blocks required for a useful quantum computer. In many of these experiments, precisely tuned lasers control and manipulate the quantum bit (qubit) represented in the electronic energy levels of the ion or atom. Scaling these systems to the necessary number of qubits needed for meaningful calculations, requires the development of scalable optical technology capable of delivering laser resources across an array of ions or atoms. That scalable technology is currently not available.</p><p>In this dissertation, I will report on the development, design, characterization, and implementation of an optical beam steering system utilizing microelectromechanical systems (MEMS) technology. Highly optimized micromirrors enable fast reconfiguration of multiple laser beam paths which can accommodate a range of wavelengths. Employing micromirrors with a broadband metallic coating, our system has the flexibility to simultaneously control multiple beams covering a wide range of wavelengths. </p><p>The reconfiguration of two independent beams at different wavelengths (780 and 635 nm) across a common 5x5 array of target sites is reported along with micromirror switching times as fast as 4 us. The optical design of the system minimizes residual intensity at neighboring sites to less than 40 dB below the peak intensity. Integration of a similar system into a neutral atom QIP experiment is reported where 5 individually trapped atoms are selectively manipulated through single qubit rotations with a single laser source. This demonstration represents the first application of MEMS technology in scalable QIP laser addressing.</p> / Dissertation

There is currently a paucity of literature in the field to provide clinicians guidance regarding best practices when clients make racist comments during individual therapy. As of this writing, very little theoretical literature and no empirical literature had been published on the topic. To address this gap in the literature, the current study used a mixed-methods design to investigate the topics. The investigation queried clinicians trained in Clinical and Counseling Psychology who had had at least three years of experience working with adult clients in individual therapy. As a starting point, the investigation focused on participants' experiences when White clients made racist comments, as White individuals have historically held more social power than People of Color. As the first of its kind, this exploratory study asked participants what they do when their White clients make racist comments in session and what factors (i.e., motivators, barriers, and other influencing factors) influence their decision-making in these situations. Data analysis was also done to identify some characteristics of the clinician that relate to the behaviors in which the clinician engages when clients make racist comments in therapy. Participants reported engaging in a range of behaviors from ignoring the comment or changing the subject to directly confronting the client's comment, labeling it racist and processing this with the client. In general, participants reported wanting to intervene with the comments more than they actually did. They indicated that the factors that influenced their behaviors included their own values regarding eradicating racism, their theoretical orientations, a desire to keep the focus on the client's presenting concern, and concerns about negative consequences that might result from confronting the comments. The information gleaned from the current study can be useful in beginning the conversation about what to do in these situations so that psychology's value of multiculturalism is upheld while also respecting clients' individual beliefs and values as well as their autonomy in therapy. It is hoped that this information will prompt additional process research in this area to establish best practices for therapeutically addressing racism and other forms of prejudice as they arise in therapy.

Made available in DSpace on 2014-06-12T15:57:34Z (GMT). No. of bitstreams: 2 arquivo3208_1.pdf: 2070521 bytes, checksum: e116b054c78a9f150df6289d879355a2 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2010 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Rede Móvel Ad Hoc (MANET) é uma rede sem fio onde os nós podem se mover livremente e formar, dinamicamente, topologias de rede temporárias e arbitrárias sem qualquer controle centralizado ou infra-estrutura de comunicação estabelecida previamente. Nestas redes, os nós agem de maneira cooperativa, encaminhando pacotes uns aos outros, de forma a possibilitar a comunicação entre pares de nós que se encontram fora do alcance direto de transmissão sem fio. Nos últimos anos, as pesquisas direcionadas à MANETs têm recebido grande atenção do governo, academia e indústria. Contudo, ainda existem algumas questões em aberto relativas à implantação de MANETs que impedem o desenvolvimento de aplicações reais e difusão das mesmas. O avanço das pesquisas nesta área poderia melhorar o desempenho atual no uso destas redes, bem como propiciar o surgimento de novos campos de aplicação. Além disso, ainda existe um grande potencial econômico a ser explorado no que se refere ao uso de redes móveis ad hoc. Um dos principais desafios relativos à implantação de MANETs é a configuração adequada dos endereços de rede. Tais endereços precisam ser únicos dentro do mesmo domínio de roteamento, ou em outras palavras, um MANET não deve conter dois dispositivos configurados com o mesmo endereço de rede. A configuração estática dos nós ad hoc não é viável devido à natureza dinâmica destas redes, e esquemas tradicionais desenvolvidos para as redes infraestruturadas não são adequados. Estas questões motivaram algumas pesquisas destinadas à permitir que os nós se configurarem sem intervenção humana, resultando em uma série de métodos para configuração automática de endereços. Estas soluções, no entanto, apresentam uma série de limitações, relacionadas principalmente à aplicabilidade em cenários restritos ou introdução elevada de sobrecarga na rede. Este trabalho apresenta um método escalável e eficiente para alocação e organização do espaço de endereçamento em redes móveis ad hoc. Uma revisão bibliográfica dos trabalhos existentes é apresentada, considerando as vantagens e limitações de cada um. Por fim, o trabalho apresenta uma avaliação preliminar do método proposto, considerando diferentes cenários e métricas

Made available in DSpace on 2014-06-12T15:58:12Z (GMT). No. of bitstreams: 2 arquivo3306_1.pdf: 1929205 bytes, checksum: 4bc1264cd60b8a95aeea33d15d66ee42 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2010 / Faculdade de Amparo à Ciência e Tecnologia do Estado de Pernambuco / Intercomunicação na próxima geração de redes de comunicação (NGN) é baseada nos conceitos de sistemas autônomos. As idéias de Computação Ubíqua estão próximas da realidade à medida que as tecnologias de redes e telecomunicações estão rapidamente convergindo para a automação. Podemos observar que o crescimento de comunicações sem fio resultou em uma rápida evolução desses sistemas, de redes infra-estruturadas a redes ad-hoc. Tecnologias de computação Pervasiva vêm para apoiar esse conceito, com o principal objetivo de permitir que usuários se conectem as redes sem necessitar de configuração manual e operar de forma transparente e suave . Tecnologias para a automação de sistemas devem abranger todas as camadas da arquitetura de redes e operar de modo cooperativo entre elas. Tecnologias de auto-configuracao vão desde a configuração básica e composição da rede até o nível de aplicações. Podemos considerar que endereçamento é um dos processos fundamentais ao configurar e iniciar uma rede. Endereçamento adequado provê os nós com identificação válida, que será utilizada, por exemplo, para roteamento e operações de segurança. Sendo que esta é uma área relativamente nova, grupos de pesquisa da indústria e academia têm desenvolvido orientações (guidelines) para endereçamento em redes autônomas. Algumas soluções já foram propostas. Mas, devido suas peculiaridades, elas têm aplicabilidade bastante limitada. Essa dissertação tem como objetivo apresentar um protocolo de endereçamento em sistemas de redes autônomas. Esse protocolo é parte de um projeto maior no contexto de redes auto-configuráveis e auto-gerenciáveis, que é liderado pela Ericsson Research Labs. Experimentos também foram conduzidos com o protocolo proposto para avaliar seu desempenho e, através de comparações com outras soluções de endereçamento, validar suas funcionalidades básicas