The growing speed and bandwidth requirements of telecommunication systems demand all-optical on-chip solutions. Microphotonic devices can deliver low power nonlinear signal processing solutions. This thesis looks at the slow light photonic crystals in chalcogenide glasses to enhance low power nonlinear operation. I demonstrate the development of new fabrication techniques for this delicate class of materials. Both, reactive ion etching and chemically assisted ion beam etching are investigated for high quality photonic crystal fabrication. A new resist-removal technique was developed for the chemical, mechanical and light sensitive thin films. I have developed a membraning method based on vapor phase etching in combination with the development of a save and economical etching tool that can be used for a variety of vapour phase processes. Dispersion engineered slow light photonic crystals in Ge₃₃As₁₂Se₅₅ are designed and fabricated. The demonstration of low losses down to 21±8dB/cm is a prerequisite for the successful demonstration of dispersion engineered slow light waveguides up to a group index of around n[subscript(g)] ≈ 40. The slow light waveguides are used to demonstrate highly efficient third harmonic generation and the first advantages of a pure chalcogenide system over the commonly used silicon. Ge₁₁.₅As₂₄24Se₆₄.₅ is used for the fabrication of photonic crystal cavities. Quality factors of up to 13000 are demonstrated. The low nonlinear losses have enabled the demonstration of second and third harmonic generation in those cavities with powers up to twice as high as possible in silicon. A computationally efficient model for designing coupled resonator bandpass filters is used to design bandpass filters. Single ring resonators are fabricated using a novel method to define the circular shape of the rings to improve the fabrication quality. The spectral responses of the ring resonators are used to determine the coupling coefficient needed for the design and fabrication of the bandpass filters. A flat top bandpass filter is fabricated and characterized as demonstration of this method. A passive all-optical regenerator is proposed, by integrating a slow-light photonic crystal waveguide with a band-pass filter based on coupled ring resonators. A route of designing the regenerator is proposed by first using the dispersion engineering results for nonlinear pulse propagation and then using the filter responses to calculate the nonlinear transfer function.

The field of nanophotonics is a major research topic, as it offers potential solutions to important challenges, such as the creation of low power, high bandwidth interconnects or optical sensors. Within this field, resonant structures and slow light waveguides are used to improve device performance further. Photonic crystals are of particular interest, as they allow the fabrication of a wide variety of structures, including high Q-factor cavities and slow light waveguides. The high scattering loss of photonic crystal waveguides, caused by fabrication disorder, however, has so far proven to be the limiting factor for device applications. In this thesis, I present a detailed study of propagation loss in slow light photonic crystal waveguides. I examine the dependence of propagation loss on the group index, and on disorder, in more depth than previous work by other authors. I present a detailed study of the relative importance of different components of the propagation loss, as well as a calculation method for the average device properties. A new calculation method is introduced to study different device designs and to show that photonic crystal waveguide propagation loss can be reduced by device design alone. These “loss engineered” waveguides have been used to demonstrate the lowest loss photonic crystal based delay line (35 dB/ns) with further improvements being predicted (< 20 dB/ns). Novel fabrication techniques were investigated, with the aim of reducing fabrication disorder. Initial results showed the feasibility of a silicon anneal in a nitrogen atmosphere, however poor process control led to repeatability issues. The use of a slow-fast-slow light interface allowed for the fabrication of waveguides spanning multiple writefields of the electron-beam lithography tool, overcoming the problem of stitching errors. The slow-fast-slow light interfaces were combined with loss engineering waveguide designs, to achieve an order of magnitude reduction in the propagation loss compared to a W1 waveguide, with values as low as 130 dB/cm being achieved for a group index around 60.

In an era of accountability and increased state control of curriculum, curriculum guides have become important legal documents, and many local districts seek to produce documents as a framework for both district and state objectives . Such curriculum development is a complex process. This study examined the curriculum procedures, roles of the participants , decision-making processes, and perceptions of the resulting documents in five school districts. Qualitative data collection included taped interviews using a focused in-depth interview schedule, field notes, observation, and document collection. The study included central administrators, building administrators, and teachers. Data Analysis was an interative, on-going process using a constant-comparative analysis of coded categories emerging from the transcribed data. This comparison examined curriculum models, curriculum trends, and teacher and administrator perceptions. The study of the curriculum processes in each district resulted in the development of a five-step curriculum model: pre-planning, planning, writing, implementation, and revision. Naturalistic models developed in each district as the curriculum was impacted by various pressures and influences. Within the five areas of each curriculum model, several patterns emerged. Each district had some impetus for a new curriculum direction. All districts reported some kind of data gathering within the planning stage and intensive training of teachers during the writing stage. The curriculum writers spoke of developing goals, objectives, strategies and of deciding upon content and document format. Many mentioned a negotiation system for decision-making. During curriculum planning and development, central office administrators formulated and approved policy, teachers documented district policy, and building administrators monitored its implementation. The emerging themes suggest the effects of a school district's environment on the curriculum process and the importance of an influential person to monitor all stages of the procedure. The themes indicate the strong move toward centralization of curriculum as a result or increasing state mandates, and demonstrate that teachers derive a sense of satisfaction and "ownership" of curriculum documents as they take part in curriculum planning and writing.

Les connaissances décisionnelles sont un type particulier de connaissances dont le but est de décrire des processus de prise de décision. En cancérologie, ces connaissances sont généralement regroupées dans des guides de bonnes pratiques cliniques. Leur publication est assurée par des organismes médicaux suite à un processus d'édition collaboratif complexe. L'informatisation des guides a conduit à la volonté de formaliser l'ensemble des connaissances contenues de manière à pouvoir alimenter des systèmes d'aide à la décision. Ainsi, leur édition peut être vue comme une problématique d'acquisition des connaissances. Dans ce contexte, le but de cette thèse est de proposer des méthodes et des outils permettant de factoriser l'édition des guides et leur formalisation. Le premier apport de cette thèse est l'intégration des technologies du Web social et sémantique dans le processus d'édition. La création du wiki sémantique OncoLogiK a permis de mettre en oeuvre cette proposition. Ainsi, un retour d'expérience et des méthodes sont présentés pour la migration depuis une solution Web statique. Le deuxième apport consiste à proposer une solution pour exploiter les connaissances décisionnelles présentes dans les guides. Ainsi, le framework KCATOS définit un langage d'arbres de décision simple pour lequel une traduction reposant sur les technologies du Web sémantique est développée. KCATOS propose en outre un éditeur d'arbres, permettant l'édition collaborative en ligne. Le troisième apport consiste à concilier dans un même système les approches pour la création des guides de bonnes pratiques informatisés : l'approche s'appuyant sur les connaissances symbolisée par KCATOS et l'approche documentaire d'OncoLogiK. Leur fonctionnement conjoint permet de proposer une solution bénéficiant des avantages des deux approches. De nombreuses perspectives sont exposées. La plupart d'entre elles visent à améliorer les services aux utilisateurs et l'expressivité de la base de connaissances. En prenant en compte le travail effectué et les perspectives, un modèle réaliste visant à faire du projet Kasimir un système d'aide à la décision complet est proposé / Decision knowledge is a particular type of knowledge that aims at describing the processes of decision making. In oncology, this knowledge is generally grouped into clinical practice guidelines. The publication of the guidelines is provided by medical organizations as a result of complex collaborative editing processes. The computerization of guides has led to the desire of formalizing the knowledge so as to supply decision-support systems. Thus, editing can be seen as a knowledge acquisition issue. In this context, this thesis aims at proposing methods and tools for factorizing editing guides and their formalization. The first contribute on of this thesis is the integration of social semantic web technologies in the editing process. The creation of the semantic wiki OncoLogiK allows to implement this proposal. Thus, a feedback and methods are presented for the migration from a static web solution. The second contribution consists in a solution to exploit the knowledge present in the decision-making guides. Thus, KcatoS framework defines a simple decision tree language for which a translation based on semantic web technologies is developed. KcatoS also proposes an editor of trees, allowing collaborative editing online. The third contribution is to combine in a single system approaches for the creation of clinical guidelines: the approach based on the knowledge symbolized by KcatoS and the documentary approach symbolized by OncoLogiK. Their joint operation can propose a solution benefiting from the advantages of both approaches. Many future works are proposed. Most of them aim at improving services to users and the expressiveness of the knowledge base. Taking into account the work and prospects, a realistic model to create a decision-support system based on clinical guidelines is proposed

Made available in DSpace on 2016-04-04T18:33:16Z (GMT). No. of bitstreams: 1 HENRIQUE DA SILVA LOURENCO.pdf: 2848034 bytes, checksum: 2a911a2ad77a2f6a8103715f0138d28c (MD5) Previous issue date: 2014-02-26 / This work falls within the field of research on educational assessment and focuses on the study of the resulting classifications of the Guia do Estudante (GE), published by Editora Abril. The dearth of research focused on the study of this problem becomes relevant, in that it aims to understand how the process of reporting the results obtained by Brazilian universities - public and private (with or nonprofit) occurs in the Award in Best Universities of GE, in the years 2012 and 2013, before the university community and society in general. This is a quantitative and qualitative research, of bibliographical nature, marked by the content analysis of sources of institutional origin, trying to know the communication strategies adopted by universities as regards the results obtained in the Best Universities GE Award. For this, understanding the process of institutional communication that originates from the GE ratings requires that seek the understanding of the place occupied by the rankings in contemporary higher education, as alleged inducing elements of quality and institutional distinction, identifying, analyzing and comparing communication strategies adopted among different segments university, from the performance in that ranking, trying to identify similarities, differences and convergences. This study is contextualized in two bibliographic-documentary surveys: one of theoretical nature and another of empirical nature. The theoretical survey is based on trying to understand how to position the main authors around policy-focused review rankings as well as policies for large-scale and unofficial rankings and concerning the internationalization of universities. The empirical survey is based on two phases: the first conducts a survey via institutional websites of universities seeking communication/advertising material about positions occupied in GE; the second phase was held on the occasion own collection of Editora Abril, where was collected editions dealing with reviews of GE. The survey results indicate that the GE had several methodological issues throughout their changes, as well as have emerged a series of ratings (rankings). The standardization of rankings GE emerged only with the "Best Universities Award". The presence of a ranking as the GE demonstrated its compliance with respect to the global movement for a culture of ranking. A content analysis of institutional materials revealed certain differences, especially in terms of marketing between public and private institutions, as well as, demonstrated the use of rankings in marketing education in view of the importance that the segments assign to the ranking of GE. / A presente disserta??o se enquadra no campo das pesquisas em avalia??o educacional e tem foco no estudo das classifica??es advindas do Guia do Estudante (GE), publicada pela Editora Abril. A escassez de pesquisas voltadas ao estudo da problem?tica torna relevante a presente investiga??o, na medida em que se pretende compreender como ocorre o processo de comunica??o dos resultados obtidos pelas universidades brasileiras p?blicas e particulares (com ou sem fins lucrativos) no Pr?mio Melhores Universidades do GE nos anos de 2012 e 2013, perante a comunidade universit?ria e a sociedade em geral. Trata-se de uma pesquisa quantitativa e qualitativa, de natureza bibliogr?fica, marcada pela an?lise de conte?do de fontes de origem institucional, tentando conhecer as estrat?gias de comunica??o adotadas pelas universidades no tocante aos resultados obtidos no Pr?mio Melhores Universidades do GE. Para tanto, compreender o processo de comunica??o institucional que se origina das classifica??es do GE exige que se busque o entendimento acerca do lugar ocupado pelos rankings na educa??o superior contempor?nea, como supostos elementos indutores de qualidade e de distin??o institucional, identificando, analisando e comparando as estrat?gias de comunica??o adotadas entre os diferentes segmentos universit?rios, a partir do desempenho no referido ranking, tentando identificar semelhan?as, diferen?as e converg?ncias. Este estudo se contextualiza em dois levantamentos bibliogr?ficos-documentais, um de cunho te?rico e outro de cunho emp?rico. O te?rico fundamenta-se na tentativa de compreender como se posicionam os principais autores em torno de pol?ticas de avalia??o focadas nos rankings, bem como de pol?ticas de larga escala e de rankings n?o oficiais e a respeito da internacionaliza??o das universidades. O emp?rico fundamenta-se em duas fases: a primeira realiza um levantamento via sites institucionais das universidades buscando material de comunica??o/publicidade que tratem das posi??es ocupadas no GE; e a segunda foi realizado no pr?prio acervo da Editora Abril ocasi?o em que se coletou as edi??es que tratam das avalia??es do GE. Os resultados da pesquisa indicam que o GE apresentou diversas mudan?as metodol?gicas ao longo de suas edi??es, assim como tamb?m foram surgindo uma s?rie de classifica??es (rankings). A padroniza??o dos rankings do GE emergiu apenas com o Pr?mio Melhores Universidades . A presen?a de um ranking como o do GE demostrou sua conson?ncia com rela??o ao movimento global em prol de uma cultura de ranqueamento. A an?lise do conte?do dos materiais institucionais revelou certas diferen?as, principalmente, em termos de marketing entre institui??es p?blicas e privadas, bem como, demonstrou o uso mercadol?gico dos rankings na educa??o tendo em vista a import?ncia que os segmentos atribuem ao ranqueamento do GE.

"Optical vortices are singularities in phase fronts of laser beams. They are characterized by a dark core whose size may dramatically affect their behavior upon propagation. Previously, only large-core vortices have been extensively studied. The object of the research presented in this dissertation was to explore ways of generating small-core optical vortices (also called optical vortex filaments), and to examine their propagation using analytical, numerical and experimental methods. Computer-generated holography enabled us to create arbitrary distributions of optical vortex filaments for experimental exploration. We used hydrodynamic paradigms to develop an heuristic model which described the dependence of vortex motion on other vortices and the background beam, both qualitatively and quantitatively. We predicted that pair of optical vortex filaments will rotate with angular rates inversely proportional to their separation distance (just like vortices in a fluid). We also reported the first experimental observation of this novel fluid-like effect. It was found, however, that upon propagation in linear media, the fluid-like rotation was not sustained owing to the overlap of diffracting vortex cores. Further numerical studies and experiments showed that rotation angle may be enhanced in nonlinear self-defocusing media. The results presented in this thesis offer us a better understanding of dynamics of propagating vortices which may result in applications in optical switching, manipulation of micro-particles and optical limiting."

"Photonic crystals have recently been the subject of studies for use in optical signal processing. In particular, a Coupled Resonator Optical Waveguide (CROW) structure has been considered by M. F. Yanik and S. Fan in “Stopping Light All Optically” for use in a time-varying optical system for the storage of light in order to mitigate the effects of waveguide dispersion. In this thesis, the effects of the thermal field on the state stored in such a structure is studied. Through simulation, this thesis finds that when this structure is constructed of gallium arsenide cylinders in air, loss of the signal was found to be caused by free-carrier absorption, and the decay of the signal dominates over thermal spreading of the optical signal’s spectrum."

Submitted by Filipe dos Santos (fsantos@pucsp.br) on 2017-02-22T11:44:17Z No. of bitstreams: 1 Elisangela Santos de Miranda.pdf: 3025343 bytes, checksum: 0b51ac7269b0a06e4469a9e462b50d14 (MD5) / Made available in DSpace on 2017-02-22T11:44:17Z (GMT). No. of bitstreams: 1 Elisangela Santos de Miranda.pdf: 3025343 bytes, checksum: 0b51ac7269b0a06e4469a9e462b50d14 (MD5) Previous issue date: 2017-02-13 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / This research starts from a debate about a possible conflict of interest between traditional members of the community and need to protect natural resources in conservation units open to visitors. In these territories, the concept of preservation favours social transformations that have as a backdrop the landholding issues, as well as tourism expectations. We took as case study the implantation of the 'Cavernas do Peruaçu National Park', through the professional practice of the local tour guides. We aimed to understand the relationship between the local population with the park from the tour guide's view. The research took place as soon as the park started to receive visitors, we have elaborated a plan conducted by some of the tour guides which were also part of the local community. To achieve the objective of this study, interviews were conducted with the local tour guides to understand how they position themselves in relation to tourism and the environmental conservation, and how they present the park to the visitors. During all visits to the park, we read some of the official local documents, we created a diary to record all notes as well as engaging in conversations with the tour guides. We focused on how to understand the language in the social aspect, we have also focused on natural language. In other words, how discursive practices produce cultural meanings and how people position themselves in their everyday relations / Essa pesquisa parte do debate sobre os possíveis conflitos de interesses entre populações tradicionais e a necessidade de proteção dos recursos naturais em unidades de conservação abertas à visitação turística. Nestes territórios a concepção preservacionista, favorece transformações sociais, que têm como pano de fundo questões fundiárias, bem como expectativas em relação ao turismo. Tomamos como estudo de caso a implantação do Parque Nacional Cavernas do Peruaçu, através da prática profissional dos guias locais, que conduzem os visitantes, buscamos compreender a relação da população local com o parque a partir da visão dos guias. A pesquisa ocorreu no momento inicial em que o parque recebe visitações. No entanto, com um plano de manejo elaborado, em execução e tendo como condutores parte da comunidade local. Para alcançar o objetivo deste estudo foram feitas entrevistas, com os guias locais, a fim de compreender como os mesmos se colocam em relação ao turismo, à conservação ambiental e como apresentam o parque aos visitantes. Também foram realizadas leituras de documentos oficiais e literatura sobre a temática, anotações em diário de campo e conversas no cotidiano durante as visitas ao parque. Orientamo-nos por uma perspectiva construcionista com entendimento da linguagem como prática social. Mais especificamente, como linguagem em ação, ou seja, como práticas discursivas a partir das quais as pessoas produzem sentidos e se posicionam em suas relações no cotidiano

Made available in DSpace on 2016-04-26T18:13:19Z (GMT). No. of bitstreams: 1 Cynthia Arantes Ferreira Luderer.pdf: 29790116 bytes, checksum: 97aca5a01e9aa4cc8b22ad46f6298dfa (MD5) Previous issue date: 2013-09-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The objective of this research is to investigate the construction process of the image of chefs as celebrities in the boom period of gastronomy in Brazil, examining the logic of the spectacle inherent in new food models implemented in the last 20 years. The cuisine has gained importance in Brazil since 1990, becoming valued and exposed in different medium. In this context the created scenario results is an outstanding image creation of the chefs, and other professionals, as restauranters , nutritional specialists, students and technologists speeches, including press officers, journalists and critics. The new proposals and food choices are now disclosed by these actors within a show, where the audience is asked to participate in blogs, television, radio, newspapers, reality shows and magazines in the area. This confluence arises our research question: how the communicative devices from luxury magazines intervene in the construction of a show in which chefs are transformed into celebrities and as such promote new food fashion to be followed? The research corpus is composed of 25 copies of the magazines: Gula, Alta Gastronomia, Menu, Prazeres da Mesa e Go Where-Gastronomia, published in an interval of five years, since 1991, as well as the annual guide gastronomic magazine SEE Eating and Drinking in the period 2004-2010. The analysis methodology used in this research was the analysis of discourse anchored in Charaudeau and Prado, from which we study the contracts of communicative media printed evaluated. In addition to the bibliographic resources, the study was conducted in the field, with participant observation, interviews with Brazilian professionals and foreigners working in the gastronomic field and questionnaires administered to students. The central hypothesis indicates that the chefs presented as celebrities become the central characters of narratives of speakers of an emerging market power, which excels in dictating rules and models to keep a new cycle of active consumption. The concept of the field of gastronomy is supported by Bourdieu and culinary capital is presented by Naccarato and Ms. LeBesco. Aspects of the spectacle, which embodies the cuisine, were approached from Debord. Besides authors who discuss semiotics and socio cultural urban consumption, to address aspects relevant to food anthropology, this study is based on Arnaiz and Contreras / como celebridades no período do boom da gastronomia no Brasil, examinando a lógica do espetáculo inerente aos novos modelos alimentares implantados nos últimos 20 anos. A gastronomia ganhou importância no Brasil a partir de 1990, passando a ser valorizada e exposta nos diversos meios de comunicação. No cenário construído nesse contexto, resultam destacadas as figuras dos chefs de cozinha, além de outros profissionais, como restauranters, especialistas da área de alimentação, estudantes e tecnólogos de discursos, entre os quais assessores de imprensa, jornalistas e críticos. As novas propostas e escolhas alimentares passaram a ser divulgadas por esses atores no âmbito de um espetáculo, em que o público é convocado a participar em blogs, programas de televisão, rádio, jornais, reality shows e em revistas especializadas na área. Nessa confluência se coloca nossa questão de pesquisa: como os dispositivos comunicativos das revistas de luxo intervêm na construção de um espetáculo em que os chefs de cozinha são transformados em celebridades e, como tais promovem novas modalizações alimentares para serem seguidas? O corpus da pesquisa é constituído por 25 exemplares das revistas: Gula, Alta Gastronomia, Menu, Prazeres da Mesa e Go Where-Gastronomia, publicadas em um intervalo de cinco anos, desde 1991, bem como o guia anual gastronômico da revista VEJA, Comer e Beber, no período de 2004 a 2010. A metodologia de análise empregada nesta pesquisa foi a análise do discurso, ancorada em Charaudeau e Prado, a partir da qual estudamos os contratos comunicativos das mídias impressas avaliadas. Além dos recursos bibliográficos, a pesquisa foi desenvolvida em campo, com a observação participativa, entrevistas elaboradas com profissionais brasileiros e estrangeiros que atuam na gastronomia e questionários aplicados a estudantes. A hipótese central indica que os chefs de cozinha, apresentados como celebridades, passam a ser os personagens centrais de narrativas dos enunciadores de um mercado emergente da alimentação, que prima em ditar regras e modelos para manter um novo ciclo de consumo ativo. O conceito de campo da gastronomia está apoiado em Bourdieu e o de capital culinário é o apresentado por Naccarato e LeBesco. Os aspectos do espetáculo, no qual se insere a gastronomia, foram abordados a partir de Debord. Além de autores que discutem a semiótica e o consumo sócio cultural urbano, para abordar os aspectos relevantes à antropologia da alimentação, este estudo está fundamentado em Arnáiz e Contreras

Dans ce travail, nous présentons la réalisation de composants originaux d’optique guidéeutilisant une technique de fabrication basée sur l'autofocalisation d’un faisceau lumineux.Cette technique permet la photo-induction de guides d’onde optiques au coeur de cristauxde LiNbO3 par effet photoréfractif.En premier lieu, des guides adiabatiques ont été générés dans des cristaux de LiNbO3 enappliquant un gradient de température selon l’axe de propagation lors de l’étaped’induction. Ces résultats expérimentaux ont été appuyés par un modèle numérique 3-Dprenant en compte la dynamique de l'effet photoréfractif.Dans un deuxième temps, nous avons démontré que la présence d’un micro-canal présentsur le trajet d’un faisceau ne perturbe pas son autofocalisation. Cette configuration a permisde fabriquer un capteur optofluidique qui permet de mesurer l'indice de réfraction d’unliquide présent dans le canal sur une plage de mesure de 1.2 à 1.8 avec une précision de4x10-3. Enfin, cette étude a été étendue à des faisceaux sous forts angles d’incidence avec lecanal ce qui a été exploité pour induire un séparateur de polarisation en optique guidée. Ceséparateur, fabriqué en une seule étape d’induction, est constitué d’un guide d’entrée seséparant en deux guides de sortie supportant des composantes croisées de polarisation. / In this work, we present the fabrication of innovative guided optics components using asimple and efficient method based on self-trapping of light beams. This technique leads tothe formation of optical waveguides inside LiNbO3 crystals by photorefractive effect.The generation of adiabatic waveguides is first achieved by applying a temperature gradientalong the propagation axis. These experimental results have been confirmed by a 3-Dnumerical model taking into account the photorefractive dynamic.Subsequently, we have shown that the presence of a micro-channel forming a gap on thebeam trajectory does not affect the self-trapping effect. This configuration has been used tofabricate an optofluidic sensor able to measure the refractive index of liquids present in thechannel with a measuring range between 1.2 and 1.8 and a resolution of 4x10-3. Finally, thisstudy has been extended to self-trapped beams at large angle of incidence with the channelwhich has been exploited to fabricate a guided polarization separator. This polarizationseparator is formed of one input waveguide that separates into two output waveguidessupporting crossed polarizations components.