The development of a new catalyst system by The Dow Chemical Company has resulted in the production of isotactic polypropylene and propylene/ethylene copolymers with a unique defect and comonomer distribution. This work investigated the morphology and optical properties of cast and compression molded films made from the homopolymer and copolymers with up to 20 mol% ethylene comonomer. The defect distribution of the Dow Chemical copolymers resulted in materials with lower crystallinity than Ziegler-Natta or metallocene-made materials of similar ethylene content. These materials exhibited a gamma-phase crystal content ranging from 0-95%, depending on ethylene content, processing condition, and catalyst type. The gamma-phase crystal content of quiescently crystallized copolymer films was found to significantly influence their bulk optical properties, presumably through a change in the spherulite birefringence. The bulk haze, clarity, and transparency of a homopolymer film were degraded through annealing treatments, which decreased the fraction of gamma-phase crystallinity and increased the thickness of existing lamellae, resulting in an increased intensity of scattered light and a corresponding degradation in the optical properties of the film. The haze, clarity, transparency, and gloss of the copolymer films were found to improve at higher comonomer content and higher cooling rates. The variation in the length scale and degree of disorder in the bulk morphology of films processed under different conditions was shown to correlate with the optical quality of the films, with smaller scale morphologies scattering less light and resulting in films with better optical properties. It was also shown that no single metric can completely describe the optical quality of a polymer film; the relative importance of haze, transparency, and gloss, which depends on the intended application of the film, was discussed. The influence of surface scattering from the films was controlled through the compression molding of films using substrates of different surface roughness. The contribution of light scattered from the surface of the films was isolated and found to play a significant role in the degradation of optical quality. / Ph. D.

Two separate lines of research in object recognition are studies of materials perception and studies of real-world object size perception. Recent object size investigations of texture indicate mid-level features may cue representations of object size in the absence of object identity. However, these findings are somewhat controversial, and beyond that what mid-level features cue object size is not clear. Mid-level features have always been the focus of materials perception studies of gloss and specular highlights, but to date no research has been conducted that attempts to link findings on the perception of materials to high-level object features like real-world object size. Three separate experiments were conducted to study the relationship between perceived surface glossiness and specular highlights, and perceived real-world object size. Previous research on the relationship between perceived object size and real-world object size were replicated. A significant two-way interaction between ratings of perceived glossiness, object size, and texture was found. Follow-up analyses indicated that perceptions of gloss were present across categorical differences in real-world object size in both the object image and texture image task groups. For the normal object images, small objects were perceived as being glossier than big objects. For the texture images, big objects were perceived as being glossier than small objects. Between the conditions, small normal and small texture object images were not significantly different in perceived glossiness. Between the conditions, glossiness ratings for big texture object images were significantly greater than those for the normal big object images. / Doctor of Philosophy / The goal of this project was to understand if category level perceptions of surface gloss (i.e. dull/matte surface reflectance versus shiny/glossy surface reflectance) could predict category level differences in the "actual" size of the objects in the real-world (i.e. small objects versus big objects). Previous research on the relationship between perceived object size and real-world object size were replicated. Moreover, in an experiment in which human subjects were tasked with rating the glossiness of images depicting small and large manmade of objects, category level distinctions in the average perceived glossiness of objects also extended to category level distinctions in perceived real-world object size; on average, small objects were perceived as being glossier than big objects. Similar effects were also found for synthetic textures created from the ordinary real-world object images; on average, big objects were rated as being glossier than small objects. Although categorical distinctions in perceived glossiness extended to real-world object size across image conditions, because there were no significant differences in the average perceived glossiness of small objects across the normal image and texture image conditions, the change in perceived glossiness for the big object images suggests that the texture algorithm used may not have preserved the surface reflectance characteristics of the big objects. Furthermore, statistical investigations of the pixel brightness for the stimulus images provided some evidence that the category level differences in perceived glossiness across object size and image condition may have been driven by differences in factors related to naturally occurring optical artifacts that are introduced when photographing small and big objects. Overall, results of this study are important because they indicate that the real-world spatial properties of objects may be jointly encoded with perceptions of object glossiness.

Submitted by PPG Letras (letraspg@pucrs.br) on 2018-03-27T20:11:16Z No. of bitstreams: 1 Disserta??o_Lucas Zambrano Rollsing.pdf: 1806949 bytes, checksum: 5d3e6e2ae93a67a88d4a722ea1c3b779 (MD5) / Approved for entry into archive by Tatiana Lopes (tatiana.lopes@pucrs.br) on 2018-04-10T11:45:03Z (GMT) No. of bitstreams: 1 Disserta??o_Lucas Zambrano Rollsing.pdf: 1806949 bytes, checksum: 5d3e6e2ae93a67a88d4a722ea1c3b779 (MD5) / Made available in DSpace on 2018-04-10T11:50:46Z (GMT). No. of bitstreams: 1 Disserta??o_Lucas Zambrano Rollsing.pdf: 1806949 bytes, checksum: 5d3e6e2ae93a67a88d4a722ea1c3b779 (MD5) Previous issue date: 2018-01-22 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / The present dissertation investigates academic Portuguese in some of its features that occur in the Postgraduate Program in Letters of the Pontifical Catholic University of Rio Grande do Sul (PPGL-PUCRS). We have set two objectives to be pursued: the primary one is to analyse pragmatically, via speech act theory (AUSTIN, 1990), acts conveyed in theses and dissertations in the PPGL corpora, in order to describe Portuguese according to its users? intentions when using acts through written academic register; the secondary objective is to propose the beginning of a Linguistics Glossary through the extraction and analysis of concepts/terms, in accordance with the Intellectual Profile of Production (IPP) of PPGL. We have adopted Pragmatics as our epistemological thread, creating conditions thus to assume the speech acts theory, as well as the textual genre theory proposed by Bazerman (2009, 2015), as theoretical models to be followed, in combination with the model of research and teaching of the area of English for Academic Purposes (JORDAN, 1997; HYLAND, 2006). Therefore, our study corpus (CorpAcad) is constituted by the academic production of PPGL within the period of eleven years (2006-2016). Among the total amount of 206 texts we have 124 dissertations and 82 theses, whose area is solely from the Linguistics field of research. The corpus processing was made by the ExATO software (LOPES, 2012), which is an automatic extractor of relevant terms (noun phrases and verbal phrases), which traces an overview of a study corpus, by linguistic and statistic methods from the area of Natural Language Processing (LOPES; FERNANDES; VIEIRA, 2016). We tried to explicit in the use contexts (verbal concordances extracted by ExATO) of the 30 most representative verbs of CorpAcad the illocutionary forces probably conveyed by the authors in the moment of writing their texts, as a methodology to describe the speech acts. Thus, we have found chiefly expositive illocutionary acts, and, in lesser quantity, commissive illocutionary acts. Our methodology to start our future Linguistics Glossary followed the extractions steps of ExATO to identify relevant concepts/terms of a corpus, which gave us a list of the most representative concepts of the area of Linguistics in that period of time for the institution above mentioned. To make the list of concepts shorter and more accurate, in order to give us a sample to analyse, concepts concerning the area of Linguistics were chosen. These concepts went through a revision by different experts of different areas of Linguistics from PUCRS to categorize them as representative terms for their study areas. From that, a terminographic product was designed to be developed which could represent the IPP of the PPGL as a whole. At the moment, we have 148 terms listed to be inserted in the macrostructure of the glossary. Finally, we hope to bring some contributions to Portuguese teaching for academic purposes in the context of PUCRS, according to what Hyland (2006) suggests as a research-based language education, in order to provide practical applications for teaching, as activities that explore acts used in texts from Linguistics. In addition, we seek to offer a reference material for students of the PPGL and for the incoming ones that represent the postgraduate program to enhance their experience while masters and doctoral students. / A presente disserta??o investiga as caracter?sticas da l?ngua portuguesa (LP) em registro acad?mico no ?mbito do Programa de P?s-Gradua??o em Letras da Pontif?cia Universidade Cat?lica do Rio Grande do Sul (PPGL-PUCRS). Para tanto, o objetivo prim?rio ? realizar uma an?lise pragm?tica, via teoria dos atos de fala (AUSTIN, 1990), de atos utilizados em teses e disserta??es defendidas no PPGL, a fim de descrever a LP de acordo com a inten??o dos seus usu?rios ao realizar atos por meio da linguagem acad?mica escrita; o objetivo secund?rio ? iniciar uma proposta de gloss?rio de Lingu?stica atrav?s da extra??o e an?lise de conceitos/termos, tendo em vista o Perfil de Produ??o Intelectual (PPI) do PPGL. Tendo a pragm?tica como respons?vel pelo assentamento epistemol?gico deste trabalho, encontramos condi??es de assumir a teoria de atos de fala, assim como a teoria de g?neros textuais proposta por Bazerman (2009, 2015), como modelos te?ricos e de an?lise lingu?stica a serem seguidos, harmonizando com o modelo de pesquisa e ensino de ingl?s para fins acad?micos (JORDAN, 1997; HYLAND, 2006). O nosso c?rpus de estudo (CorpAcad) abarca a produ??o bibliogr?fica do PPGL no intervalo de 2006 a 2016, contabilizando 206 textos, dentre os quais 124 s?o disserta??es e 82 s?o teses, versando exclusivamente sobre Lingu?stica. O processamento do c?rpus foi realizado pelo software ExATO (LOPES, 2012), o qual ? um extrator autom?tico de termos relevantes (sintagmas nominais e verbais) que permite tra?ar um panorama do c?rpus de estudo, utilizando m?todos lingu?sticos e estat?sticos da ?rea de Processamento de Linguagem Natural (LOPES; FERNANDES; VIEIRA, 2016). Nossa metodologia de descri??o dos atos de fala foi, a partir das concord?ncias verbais extra?das pelo ExATO, explicitar, nos contextos de uso dos 30 verbos mais representativos para o CorpAcad, as for?as ilocucion?rias provavelmente utilizadas pelos autores no momento de produ??o de seus textos. Encontrou-se, ent?o, majoritariamente a presen?a de atos ilocucion?rios expositivos e, em menor grau, comissivos. A metodologia empregada para a elabora??o da nossa proposta de gloss?rio de Lingu?stica seguiu os passos de extra??o de conceitos utilizados pelo ExATO, o qual nos proporcionou sintagmas representativos para a ?rea de Lingu?stica. Tendo em m?os esses conceitos, a fim de refinar a lista e torn?-la menor, foram selecionados conceitos exclusivamente referentes ?s ?reas de estudo da Lingu?stica, sendo estes mesmos conceitos revisados por estudiosos da ?rea, os quais os categorizaram como termos representativos de suas ?reas de estudo. A partir disso, foi delineado um produto terminogr?fico a ser constru?do com base nas caracter?sticas do PPI do PPGL. At? o presente momento contamos com 148 termos arrolados a serem inseridos na macroestrutura do produto terminogr?fico. Com isso, esperamos trazer contribui??es para o ensino de LP para fins acad?micos no contexto da PUCRS, seguindo o que Hyland (2006) prop?e como uma educa??o lingu?stica baseada em pesquisas cient?ficas, a fim de que possamos, atrav?s da an?lise da for?a ilocucion?ria dos atos envolvidos na escrita de uma tese ou disserta??o, proporcionar aplica??es pr?ticas para o ensino, como atividades que explorem atos utilizados em textos de Lingu?stica. Adicionalmente, buscamos oferecer um material de refer?ncia para consulta por alunos do PPGL e futuros ingressos, de acordo com a relev?ncia dos conceitos nas ?reas de estudo abarcadas pelo programa.

Advances in digital technology have recently allowed for richer text annotation in combination with authentic second language video media. As a result, many educational researchers are focusing increased attention on the effect this application of technology can have on second language acquisition. This study examines the comparative effectiveness of target vocabulary treatments with either native language (L1) definitions or target language (L2) definitions when target vocabulary is presented in either kana or kanji as a part of the subtitles of an L2 film based on participant performance on vocabulary assessments. This study also examines the participants' perceived levels of helpfulness of the varying word treatments. The results of the study suggest that providing annotations for target words in the L2 increases learning of that word more than L1 annotations for intermediate learners of Japanese. On the other hand, learners rated access to definitions in L1 as more helpful than L2 definitions, and they expressed their preference for understanding the story more than learning the target vocabulary.

Submitted by Caroline Falcao (caroline.rfalcao@ufpe.br) on 2017-06-06T17:17:02Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) 2012-Dissertacao-RenataBarretoSantos.pdf: 5151204 bytes, checksum: 5d3006258e7c3359dffead5b2f172fc4 (MD5) / Made available in DSpace on 2017-06-06T17:17:02Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) 2012-Dissertacao-RenataBarretoSantos.pdf: 5151204 bytes, checksum: 5d3006258e7c3359dffead5b2f172fc4 (MD5) Previous issue date: 2012-12-20 / Este trabalho abordou mudanças no padrão estético através do uso de ferramenta quantificadora de luz refletida, inclusive para cada espectro visível. É possível perceber mudanças que associadas à descrição petrográfica e às características tecnológicas, orientarão uma escolha consciente e precisa do material pétreo e a monitoração do seu uso. Com a diversidade de tipos de rocha ofertados hoje no mercado, percebe-se a necessidade de preparo de profissionais para identificar a rocha mais adequada para um determinado uso. Outrossim, as características e efeitos dos produtos de limpeza precisam ser sistematicamente acompanhados, de modo que a percepção estética deve ir além da beleza momentânea, inclusive servir de referência para perceber e prever suas mudanças e respectivos desdobramentos sobre propriedades mecânicas do material no decorrer do tempo e do uso estimado e, naturalmente, sua durabilidade otimizada. A permanência da estética e preservação dos parâmetros físicos e mecânicos da rocha passam a depender do aprofundamento teórico para prever a finalidade da indicação da rocha. Os estudos realizados, neste trabalho, abordam a aplicação da espectrometria e luminosidade até a implementação prática do gerenciamento de cores e do brilho, passando pela análise conceitual da cor, sistema visual humano, fontes de luz, temperatura de cor, modelos de cores, espectro eletromagnético, espectrometria, espectro-radiométria, dispositivo para aferir a cor, além de analises petrográfica e tecnológicas do material estudado. A fim de implementar o gerenciamento de cores, foi necessário equipamento de medição, cartelas de referência para calibração e software para ler os dados captados pelo equipamento de medição. Para a implementação do sistema, em caráter experimental, foram utilizadas amostras no material pétreo Preto São Marcos, e os resultados obtidos, mostram que houve alteração do índice colorimétrico e do brilho entre o material original e o sujeito a ataque químico, embora não fossem percebidas a olho nu, devido à composição mineral da rocha. / This work aims to demonstrate that through aesthetic standards it is possible to verify changes associated to petrographic description and technological features, resulted in a conscious and accurate choice of the stone material and its use. With the diversity of lithological offered in trade today, it is possible to verify the lack of professionals prepared to identify the stone most suitable for a particular use. The aesthetic perception must go beyond the momentary beauty, it is needed to understand and predict the aesthetic and mechanical changes and the properties of the material over time and its estimate use. The permanence of the aesthetics and mechanics of the rock becomes dependent on the theoretical development that provides an indication of the rock. The studies conducted in this work, address the principle, the formation of light to the practical implementation of color management and shine, through conceptual analysis of color, human visual system, light sources, color temperature, color models, electromagnetic spectrum, spectrometry, spectroradiometry, device to measure the color, and petrographic analysis of the technological material studied. In order to implement color management, measurement equipment was necessary, reference cards for calibration and Softwaer to read the data captured by the measuring equipment. To implement the system, as experimental phase, it was used samples in a stone material Preto São Marcos and the results show that there was a change in the colorimetric index and brightness between the original material and the material exposed to chemical attack, most were not perceived with the naked eye due to mineragilogica composition of the rock.

Nous interagissons quotidiennement avec une multitude de matériaux et nous pouvons sans effort identifier les différents matériaux. Nous qualifions facilement des caractéristiques à des matériaux particuliers comme matte, doux, dur, lisse, brillant, par exemple. Ces caractéristiques sont basées sur l’aspect visuel du matériau et les estimations des propriétés physiques sous-jacentes du système visuel. Cependant, la perception est un problème mathématiquement sous-constraint. La quantité de lumière atteignant notre œil dépend des propriétés de réflectance de la matière, l’éclairage de la scène et la géométrie des objets. Estimer les propriétés intrinsèques des matériaux nécessite une clarification de ces différents éléments les uns des autres. Pour estimer propriétés, intrinsèques des matériaux, il faut les étudier indépendamment les uns des autres. Dans cette thèse, j’étudie l’influence d’une propriété intrinsèque particulière : les réflexions spéculaires. J’étudie l’influence du contexte sur la brillance perçue et le rôle des autres matériaux dans la scène observée. D’autres matériaux pourraient fournir des informations supplémentaires sur les caractéristiques de la scène qui guident et façonnent le percept final. Nos résultats expérimentaux confirment que : 1. La perception de la brillance est influencée par le point de vue et la direction d’illumination. La brillance perçue est bien corrélée avec les propriétés des réflexions spéculaires sur la surface. 2. La brillance perçue est largement affectée par d’autres matériaux sur la surface indiquant que les participants prennent les informations d’autres matériaux en compte. 3. La procédure d’estimation conjointe du maximum de vraisemblance peut être utilisées pour quantifier précisément les effets contextuels dans la perception matérielle. La luminance et interagissent brillant physique et en même temps une influence sur la perception de l’autre. En conclusion, cette thèse met en évidence l’importance du contexte sur la brillance perçue. Je soutiens que la définition de constance de brillance néglige largement l’influence du contexte. La capacité du système visuel pour récupérer la réflectance de surface a été largement testée et une absence de constance de brillance ont été trouvé. Cependant, le jugement d’une seule surface dans l’isolement ne correspond pas à une tâche naturelle. D’autres matériaux et objets de la scène apportent des informations supplémentaires sur l’environnement au système visuel. Le percept final de la brillance est formé par des informations disponibles à partir de ces matériaux dans la même scène. / We interact with a multitude of different materials on a daily basis and we can effortless identify different materials. We easily add labels to particular materials like soft, hard, smooth, shiny, matte, for example. These labels are based on the visual appearances of the materials and the visual system's estimations of the underlying physical properties. However, mathematically material perception is an underconstrained problem. The light reaching our eye depends on the reflectance properties of the material, the illumination in the scene and the object's geometry. Estimating the intrinsic properties of materials requires to disambiguate these different factors from one another. In this thesis I will focus on one particular intrinsic property: Gloss. I will focus on the influence of the context onto perceived gloss and the role of other materials in the observed scene. Additional materials might provide supplementary information about the scene characteristics that guide and shape the final percept. Our experimental results confirm that: 1. Gloss perception is influenced by the viewpoint and the illumination direction. Perceived gloss correlates well with simple highlight properties on the surface. 2. Perceived gloss is largely influenced by other materials on the surface. Surfaces with two materials generate contrasting perceptual effects. 3. Maximum likelihood conjoint measurements can be used to precisely quantify contextual effects in material perception. Both, luminance and physical gloss interact and simultaneously influence each other. In conclusion, this thesis highlights the importance of the context onto perceived gloss. I argue that the definition of gloss constancy broadly neglects the influence of the context. The visual system's ability to recover the surface reflectance has extensively been tested and lacks of gloss constancy have been found. However, the judgement of a single surface in isolation does not correspond to a natural task. Other materials and objects in the scene provide the visual system with rich information about the environment (e.g. the illumination) and the final percept of the surface is formed by the additional information from these materials in the same scene.

O tratamento clareador pode resultar em alterações na rugosidade superficial do esmalte dental, as quais podem ser vistas a olho nu como alterações de cor, opacidade e perda de brilho. O objetivo deste estudo foi analisar in vitro a alteração de rugosidade, cor e brilho de superfícies de esmalte dental humano após clareamento com um produto a base de peróxido de hidrogênio (PH) 38% e após polimento com fluoreto de sódio 2% neutro (FS2%) ou pasta dentifrícia contendo partículas de nano-hidroxiapatita. Para isso, coroas de incisivos centrais humanos foram preparadas e tiveram suas faces vestibulares analisadas em microscópio de força atômica (MFA), o qual determinou os valores de rugosidade [Ra, RMS, Z range e Power Spectral Density (PSD)] iniciais. A cor e o brilho destas amostras foram determinados por um espectrofotômetro. Todas as amostras foram clareadas com PH 38% por 135 minutos. Os valores de Ra, RMS, Z range e PSD foram estabelecidos pelo MFA e a cor e o brilho determinados pelo espectrofotômetro. As amostras foram divididas em dois grupos: Flúor, que recebeu um polimento com gel de FS2%; e nHA, que recebeu um polimento com pasta dentifrícia contendo partículas de nano-hidroxiapatita. Os valores de Ra, RMS, Z range, PSD, cor e brilho pós-polimento foram determinados pelo MFA e espectrofotômetro. Após o clareamento, os valores de Ra, RMS, Z range e PSD não apresentaram alteração estatisticamente significante, os valores de L* aumentaram e C* diminuiu significativamente em todas as amostras. O brilho superficial não apresentou alteração significativa após o clareamento. O grupo Flúor não apresentou alteração de rugosidade significativa para Ra, RMS, Z range e PSD após o polimento. Os valores de L*, C* e brilho superficial também não apresentaram alterações significativas após o polimento das superfícies clareadas. No grupo nHA, os valores de Ra e RMS não apresentaram alteração significativa após o polimento das superfícies clareadas, porém os valores de Z range e PSD apresentaram alteração estatisticamente significante. Em comparação à superfície clareada, L* e C* não apresentaram alteração significante após o polimento, porém o brilho superficial foi significativamente maior. O tratamento clareador de consultório mostrou ser eficiente quanto à alteração de cor e não gerou aumento na rugosidade superficial do esmalte dental. Um polimento com pasta dentifrícia contendo partículas de nano-hidroxiapatita realizado após o clareamento é capaz de aumentar o brilho e diminuir a rugosidade superficial do esmalte dental. / Bleaching treatment may result in dental enamel surface roughness alterations, which might be seen as color alterations, opacity and gloss loss. The aim of this research was to in vitro investigate roughness, color and gloss alterations of human dental enamel surfaces after bleaching treatment with 38% hydrogen peroxide (HP) and after polishing with neutral 2% sodium fluoride or dental tooth paste containing nano-hydroxiapatite particles. Human central incisors were prepared and buccal surfaces were analyzed by an atomic force microscope (AFM), which determined roughness values [Ra, RMS, Z range and Power Spectral Density (PSD)]. Surface color and gloss were determined by a spectrophotometer. All samples were bleached with 38% HP for 135 minutes. AFM determined Ra, RMS, Z range and PSD after bleaching. Color and gloss were determined by the spectrophotometer. Samples were distributed in two different groups: Fluor, which was polished with neutral 2% sodium fluoride, and nHA, which was polished with dental tooth paste containing nano-hydroxyapatite particles. Ra, RMS, Z range, PSD, color and gloss values were determined by AFM and spectrophotometer after polishing. After bleaching, Ra, RMS, Z range and PSD didnt show any statistical difference. L* increased and C* decreased significantly in all samples after bleaching. Surface gloss didnt show significant alteration after bleaching. Fluor group didnt show surface roughness alteration considering Ra, RMS, Z range and PSD after polishing. L*, C* and gloss didnt change after bleached surfaces are polished with neutral 2% sodium fluoride. Ra and RMS of nHA group didnt change significantly after polishing, but Z range and PSD showed significant alteration. Despite L* and C* didnt change, gloss increased significantly after polishing with dental tooth paste containing nano-hydroxyapatite. In-office bleaching treatment showed to be efficient as for color enhancement and didnt cause roughness alteration in dental enamel surface. An after-bleaching polishing with dental tooth paste containing nano-hydroxyapatite particles may increase gloss and decrease surface roughness of dental enamel.

Cette thèse traite du développement d'algorithmes d'estimation en haute dimension. Ces algorithmes visent à résoudre des problèmes de discrimination et de classification, notamment, en incorporant un mécanisme de sélection des variables pertinentes. Les contributions de cette thèse se concrétisent par deux algorithmes, GLOSS pour la discrimination et Mix-GLOSS pour la classification. Tous les deux sont basés sur le résolution d'une régression régularisée de type "optimal scoring" avec une formulation quadratique de la pénalité group-Lasso qui encourage l'élimination des descripteurs non-significatifs. Les fondements théoriques montrant que la régression de type "optimal scoring" pénalisée avec un terme "group-Lasso" permet de résoudre un problème d'analyse discriminante linéaire ont été développés ici pour la première fois. L'adaptation de cette théorie pour la classification avec l'algorithme EM n'est pas nouvelle, mais elle n'a jamais été détaillée précisément pour les pénalités qui induisent la parcimonie. Cette thèse démontre solidement que l'utilisation d'une régression de type "optimal scoring" pénalisée avec un terme "group-Lasso" à l'intérieur d'une boucle EM est possible. Nos algorithmes ont été testés avec des bases de données réelles et artificielles en haute dimension avec des résultats probants en terme de parcimonie, et ce, sans compromettre la performance du classifieur. / This thesis deals with the development of estimation algorithms with embedded feature selection the context of high dimensional data, in the supervised and unsupervised frameworks. The contributions of this work are materialized by two algorithms, GLOSS for the supervised domain and Mix-GLOSS for unsupervised counterpart. Both algorithms are based on the resolution of optimal scoring regression regularized with a quadratic formulation of the group-Lasso penalty which encourages the removal of uninformative features. The theoretical foundations that prove that a group-Lasso penalized optimal scoring regression can be used to solve a linear discriminant analysis bave been firstly developed in this work. The theory that adapts this technique to the unsupervised domain by means of the EM algorithm is not new, but it has never been clearly exposed for a sparsity-inducing penalty. This thesis solidly demonstrates that the utilization of group-Lasso penalized optimal scoring regression inside an EM algorithm is possible. Our algorithms have been tested with real and artificial high dimensional databases with impressive resuits from the point of view of the parsimony without compromising prediction performances.

<p>The appearance and design of a package are key properties to attract and to focus the attention of a customer. Print quality contributes to a great degree to achieve these requirements. Most critical perceived in terms of quality are print defects like mottling, gloss and stripiness, which all appear in the printing of corrugated board. Stripiness is especially critical because it is a defect directly caused by the corrugated board construction. A further cause can be generated by the production process of corrugated board. Pre-studies by Odeberg Glasenapp (2004) revealed a difference in surface micro-roughness between the regions on the peak line of the liner and the regions in the valley between two peaks of the corrugation. This knowledge was the basis for the work described in this thesis.</p><p>In a first stage, laboratory trials were conducted with sets of coated and uncoated samples of various grammages. The trial was set-up in order to simulate the conditions in the corrugator as closely as possible. In the evaluations, it was found out that the settings were too high. For that reason, the coated samples were influenced to a too high degree and needed to be excluded from further evaluations. With the uncoated samples, on the other hand, a change in micro surface roughness was detectable. The roughness is decreased on the peaks and the gloss appearance was the conclusion. The analysis of the printed samples focused on shifts in colour and print density. It is unclear if both are affected only surface roughness changes and/or by the typical corrugated board effect of washboarding.</p><p>A full-scale test was performed in order to confirm the results of the laboratory test. A test series was chosen with coated and uncoated outer liners. Contrary to the lab-test results, the uncoated grades showed no surface roughness changes. Instead, the coated samples were affected to a great extent. The changes in surface roughness and gloss appearance were similar to the lab-test. This confirms that the lab-test samples were exposed to heat, pressure and shear to a too high degree. The print analysis of the full-scale test did not agree with the laboratory test. Gloss lines were visually detectable, but they were difficult to measure. A reason could be that the ink is capable on forming an ink film layer on top of the surface of the paper. This would cover the micro roughness of the matt parts thereby creating an almost homogeneous glossy appearance.</p>

Le brillant est un attribut de l'apparence visuelle. Il s'agit d'une construction du système visuel, basée sur le signal optique en provenance d’une surface et capté par l'œil. Les développements récents en spectrophotométrie fondamentale ont produit des instruments à même de mesurer la réflexion lumineuse avec une acuité égale à celle du système visuel humain. Une description transverse, visuelle et optique, d'un même ensemble d'échantillons est maintenant possible. Dans ce travail, nous construisons via des procédés sol-gel une échelle de brillant métrologique multivariée en termes de topologie de surface, indice de réfraction, teinte et niveaux de brillant. Cette échelle est caractérisée par la suite en rugosité, en indice de brillant spéculaire et en BRDF. Nous présentons les techniques de mesure et les corrections employées sur ConDOR, notre goniospectrophotomètre dédié à la mesure haute résolution du pic spéculaire. Au terme de cette étude, l'instrument présente une résolution angulaire de 0,014°, la meilleure résolution atteinte à ce jour, deux fois inférieure à celle du système visuel humain. La dynamique est de 6,5 décades. ConDOR est employé pour mesurer les BRDF de plusieurs échantillons brillants issus de différentes échelles. Elles sont étudiées et les discutées. Un premier lien entre rugosité et BRDF est esquissé. Nous étudions finalement en nous basant sur une échelle de référence de brillant deux aspects de sa perception : l’effet d'un changement d'angle solide d'illumination et l’effet du réalisme de l'environnement d'observation. Nos résultats montrent que le système visuel est plus sensible aux variations de brillant dans des conditions d'observations réalistes, tant en matière d'éclairage que d'environnement. L’effet est particulièrement prononcé pour les échantillons mats. Les conditions moins réalistes ou moins naturelles peuvent mener les observateurs à la confusion. / Gloss is a visual appearance attribute. It is a construction from the visual system built on the optical signal from a surface and sensed by the eye. Recent developments in fundamental spectrophotometry lead to instruments able to measure luminous reflection with an acuity equal to the visual system in terms of angular resolution and dynamic. A cross-discipline description between optics and vision is now possible on a same set of samples. In this work, we build through sol-gel process a metrological gloss scale. It is multivariate in terms of surface topology, refractive indices, hue and gloss levels. This scale is then characterized in roughness, specular gloss and BRDF. We expose the measurement techniques and corrections used on our goniospectrophotomer ConDOR. This instrument is dedicated to high resolution measurement of specular peaks. By the end of this study, Condor has reached an angular resolution of 0.014°, the smaller achieved until now, twice better than the human visual system acuity. The dynamic range extends over 6.5 decades. ConDOR is used to measure BRDF of several glossy samples from different scales. These measurements are studied and discussed. A first link between roughness and BRDF is drawn.Using a reference gloss scale, we finally study two aspects of gloss perception: both effects of a change in the solid angle of illumination and in the observation environment realism. Our results indicate that the visual system is more sensitive to gloss variations under realistic conditions as well in lighting as in environment. This effect is particularly noticeable on matt samples. Lesser realistic or lesser natural conditions could lead observers to confusion.