This study investigated the electro-optic characteristics of VAN ¡]vertical-alignment nematic¡^liquid crystal device in passive mode, and tried to present the advantage of high contrast ratio which belongs to VA mode. The experiment consisted of three parts: 1. Change different cell thickness¡]d = 12£gm¡B6£gm¡B4.9£gm¡^. 2. Chang LC with the different value of dielectric¡]£G£`= -3.7¡B-6.1¡^. 3. Chang LC with different refraction anisotropy¡]£Gn = 0.15¡B0.078¡^. We drive those samples with different number of duty in passive mode, and to measure the electro-optic characteristics, including VT curve, response time, and contrast ratio. We knew that STN¡]Super Twist Nematic LCD¡^has the drawbacks of lower contrast ratio, higher operational voltage and slower response time within higher duty in passive mode. And the same problem comes with VAN in passive-drive mode, although it is said VAN has the high performance of contrast ratio. The contrast ratio is worse then STN when driving in higher duty. As a result of VAN is kind of ECB mode, its transparency has a big matter with light retardation. We find that in the same condition of driving duty, the value of cell gap or the £Gn become larger, the value of the sharpness and the contrast ratio become larger.

<p>What is meant with print quality, what makes people perceive the quality of an image in a certain way? An inquiry was made about what the parameters are that strongly affect the perception of digital printed images. </p><p>A subjective test and some measurements make the basis for the thesis. The goal was to find a tool to predict perceived image quality when investigating the connections between the subjective test and the measurements. </p><p>Some suitable images were chosen, with a variety of motifs. A test panel consisting of people that are used to observe image quality answered questions about the perception of the quality. Measurements were made on a special test form to get information about the six different printers used in the investigation. </p><p>One of the discoveries was made when two images with the same colorful motif were compared. The first image got a much higher grade for general quality than the second image, even though the second image was printed with a printer that had a larger color gamut. The reason of this is that the first image consists of more saturated colors, and the second image has more details. The human eye perceives the more saturated image to be better than the image with more details. Another discovery was the correlation between the perceived general quality of a colored image and the perceived color gamut. One conclusion was that a great difference between two calculated color gamuts resulted in a large difference in perception of the color gamuts. A discovery of an image with very few colors and many glossy surfaces was that print mottle and sharpness are strictly connected to the general quality.</p>

Das Ziel dieser Untersuchung ist es, Aspekte der Strukturqualität (technische Untersuchungs- und Bildqualität), Prozessqualität (Angemessenheit der Indikation) und der Ergebnisqualität (Richtigkeit der Befunderhebungen) von Röntgenaufnahmen aus der tierärztlichen Praxis zu erörtern und häufige Fehlerquellen festzustellen. Dazu werden alle Röntgenaufnahmen von Kleintieren, die im Zeitraum von Anfang Dezember 2003 bis Ende Dezember 2004 als Original in die Klinik für Kleintiere der Universität Leipzig gelangen auf praxisrelevante Merkmale der Struktur-, Prozess- und Ergebnisqualität hin untersucht. Die Ermittlung der Daten erfolgt auf subjektiver Grundlage anhand eines Befundbogens durch Konsensbeurteilung von zwei Unter-suchern. Zur Auswertung gelangen 1259 Röntgenaufnahmen aus 600 verschiedenen Untersuchungen. Diese Aufnahmen stammen zu 86,9 % aus den Bundesländern Sachsen, Sachsen-Anhalt und Thüringen von 216 verschiedenen Tierarztpraxen. 80,3 % der untersuchten Tiere sind Hunde, 18,9 % Katzen. In der Gesamtbeurteilung der Bildqualität erweisen sich 48,7 % der Aufnahmen ohne Bean-standung. 29,2 % zeigen geringfügige Mängel, 16,0 % sind bedingt diagnostisch geeignet und 6,1 % sind unzureichend. 22,1 % der ausgewerteten Aufnahmen sind somit mangelhaft. Sie weisen Defizite in der diagnostischen Eignung auf oder sind hierfür ungeeignet. Die wichtigsten Fehlerquellen der Strukturqualität sind Mängel der Lagerung und Projektion, des Bildkontrastes und der Bildschärfe. Abweichungen der Lagerung und Projektion, meist durch nicht winkelgerechte Lagerung des Patienten im Direktstrahl verursacht, sind mit 11,4 % aller Aufnahmen im Vergleich zu anderen Fehlerquellen relativ selten. Die Auswirkungen auf die diagnostische Eignung sind jedoch oft schwerwiegend: 69,9 % der von Mängeln in der Lagerung betroffenen Aufnahmen zeigen Einschränkungen hinsichtlich der diagnostischen Eignung. 33,3 % aller Aufnahmen weisen Abweichungen des Bildkontrastes auf. Die häufigste Ursache dafür ist der Umgang mit verbrauchter Entwicklerlösung, gefolgt von Unter- und Überbelichtung. Betrachtet man die Gesamtheit der Kontrastabweichungen kann festgestellt werden, dass 47,7 % auf Fehler in der Filmentwicklung zurückzuführen sind. Auswirkungen auf die Eignung zur Diagnosestellung sind weniger gravierend als bei Mängeln der Lagerung und Projektion: 35,1 % der von Kontrastabweichungen betroffenen Aufnahmen zeigen Einschränkungen des diagnosti-schen Nutzens. 23,0 % der Aufnahmen sind durch Abweichungen der Bildschärfe gekennzeichnet. Am häufigs-ten ist Bewegungsunschärfe (67,7 % der betroffenen Aufnahmen) zu ermitteln. Weiterhin wer-den oft Materialunschärfe und Unschärfe durch Streustrahlung beobachtet, die auf den falschen Umgang mit dem Streustrahlenraster und der Film-Folien-Kombination zurückzuführen sind. Die Auswirkungen auf die diagnostische Eignung zeigen, dass 29,6 % der Röntgenaufnahmen mit Abweichungen der Bildschärfe Einschränkungen des diagnostischen Nutzens nach sich ziehen. Artefakte, vor allem verursacht durch Kratzer, Risse oder Brüche in Film oder Folie sowie durch Verunreinigungen durch Entwickler-, Fixierlösung oder Wasser, sind bei 20,7 % aller Röntgen-aufnahmen zu finden. Einschränkungen der diagnostischen Eignung ergeben sich dadurch bei 1,2 % der analysierten Aufnahmen. Zur Untersuchung der Prozessqualität wird die Angemessenheit der Indikation ermittelt, die nach RöV § 2a für jede Röntgenaufnahme gegeben sein muss (ANON. 2003a). Eine absolute Indikation kann bei 94,7 % der ausgewerteten Aufnahmen festgestellt werden. Bei knapp der Hälfte aller Aufnahmen dieser Arbeit kann die Ergebnisqualität erörtert werden. Die gestellte radiologische Verdachtsdiagnose ist bei 85,5 % dieser Fälle medizinisch nachvoll-ziehbar. Aus den Ergebnissen dieser Arbeit lässt sich ableiten, dass ein wesentlicher Teil der vorkom-menden Mängel der Bildqualität auf ungenügende Sorgfalt bei der Anfertigung und Verarbeitung der Röntgenaufnahme zurückzuführen ist. Allerdings liegen auch Defizite bei der Interpretation der gewonnenen Information durch die Röntgenuntersuchung vor. Da jeder Anwender ionisierender Strahlen verpflichtet ist, jede unnötige Strahlenexposition von Mensch und Umwelt zu vermeiden, müssen bestehende Defizite in Bezug auf die Anwendung der Projektionsradio-grafie abgebaut werden und die Vermittlung von Wissen und praktischen Fertigkeiten auf diesem Gebiet während der tierärztlichen Ausbildung verbessert werden. Ebenso sollte eine Feh-lerbeseitigung durch Ausnutzung oder Verbesserung der technischen Möglichkeiten erfolgen. Eine erneute Untersuchung zur Qualität von Röntgenaufnahmen in der tierärztlichen Praxis auf der Grundlage dieser Studie erscheint zur Überprüfung der getroffenen Maßnahmen zur Ver-besserung der Bildqualität sinnvoll. / The aim of this study is to evaluate aspects of structural quality (technical examination and im-age quality), quality of the process (adequacy of indication) and the outcome (correctness of findings) of radiographs from the veterinary practice and to indentify frequent radiographic er-rors. For this purpose all radiographs of small animals that are received at the Department of Small Animal Medicine of the University of Leipzig between December 1st 2003 and December 31th 2004 as an original are examined for relevant features of structural quality, process quality and outcome. The data collection is done subjectively based on the consensus examination of the radiographs by two independent examiners. The evaluation includes 1259 radiographs from 600 different examinations. 86.9 % of these images come from the federal states of Germany Saxony, Saxony-Anhalt and Thuringia from 216 different veterinary practices. 80.3 % of the examined animals are dogs, 18.9 % are cats. Concerning the over-all evaluation of the image quality, 48.7 % of the radiographs are without restrictions. Minor faults are detected in 29.2 % of the radiographs, 16.0 % are diagnostically compromised and 6.1 % are insufficient. Thus, 22.1 % of the examined radiographs are unsatis-factory. They show either deficits in their diagnostic suitability or are completely useless. The most important sources of errors are faults in positioning of the patient and the following projec-tion, of image contrast and sharpness. Deviations in positioning and projection, mostly caused by a suboptimal angle in the position of the patient in the x-ray, are with 11.4 % of all radiographs in comparison to other errors relatively rare. However the effect on the diagnostic use is severe: 69.9 % of the images with positioning faults show deficits with regard to the diagnostic suitability. Regarding the contrast of the image, 33.3 % of all radiographs display deficits. The most com-mon cause is the use of exhausted developer, followed by under- and overexposure. Consider-ing the overall deviations of image contrast, 47.7 % are attributed to errors during the x-ray film development. Consequences for the diagnostic use are less serious compared to errors in posi-tioning and projection: 35.1 % of the images with contrast deviations are of limited diagnostic use. 23.0 % of the radiographs are characterized by deviations in the sharpness: motion haziness occurs most frequently (in 67.7 %) of the images concerned. Receptor unsharpness and scat-tered radiation are often observed, caused by improper use of radiographic grids and film-screen combinations. The effects on the diagnostic suitability show that 29.6 % of the radiographs with deviations in the sharpness are of limited diagnostic use. Artifacts, most frequently caused by scratches, tears and breaks of the film or the intensifying screen as well as by splashes of the developing resp. fixation reagent or water, are found on 20.7 % of all radiographs. As a result of artifacts 1.2 % of the radiographs examined show defi-cits in their diagnostic suitability. To evaluate the quality of the process the adequacy of indication is determined, which is required for every radiographic examination according to RöV § 2a (ANON. 2003a). An absolute indication can be found in 94.7 % of all images. The quality of the outcome can be discussed in almost halve of all radiographs. The referral diagnosis is medically plausible in 85.5 % of these cases. The results of this study reveal that a considerable portion of the occurring errors in the image quality are caused by a lack of care during taking and processing of the radiographic images. Deficits in the interpretation of the gained information from the radiographic examination occur as well. Since avoidance of unnecessary exposure of humans and the environment to radiation is a major obligation of every user of ionizing radiation, existing deficits regarding the use of projection radiography should be reduced and the transfer of knowledge and practical capabili-ties in this area during the veterinary training should be improved. Furthermore, the elimination of errors by use or improvement of the technical possibilities is important. A new evaluation of the quality of radiographic images from the veterinary practice on the basis of this study seems useful to examine the effects of the steps taken to improve the image quality.

What is meant with print quality, what makes people perceive the quality of an image in a certain way? An inquiry was made about what the parameters are that strongly affect the perception of digital printed images. A subjective test and some measurements make the basis for the thesis. The goal was to find a tool to predict perceived image quality when investigating the connections between the subjective test and the measurements. Some suitable images were chosen, with a variety of motifs. A test panel consisting of people that are used to observe image quality answered questions about the perception of the quality. Measurements were made on a special test form to get information about the six different printers used in the investigation. One of the discoveries was made when two images with the same colorful motif were compared. The first image got a much higher grade for general quality than the second image, even though the second image was printed with a printer that had a larger color gamut. The reason of this is that the first image consists of more saturated colors, and the second image has more details. The human eye perceives the more saturated image to be better than the image with more details. Another discovery was the correlation between the perceived general quality of a colored image and the perceived color gamut. One conclusion was that a great difference between two calculated color gamuts resulted in a large difference in perception of the color gamuts. A discovery of an image with very few colors and many glossy surfaces was that print mottle and sharpness are strictly connected to the general quality.

This thesis deals with quality of digital images and with methods for measurement their numerical characteristics. Our attention is drawn to measurement of sharpness, as a main factor of image quality, in both space and spectral domain. For this reason, the Fourier and the discrete Fourier transform is described in one and two dimensions. Methods, presented in this work and implemented on attached CD, can be used for automatic image quality classification and autofocus of optical systems.

Continuous improvement of image quality is one of the priorities in medical imaging. Therefore, development of a simulation tool allowing to generate realistic images would be of great value to understand better the impact of the components on the image quality metrics and to choose imaging set-ups or new design features to optimize output of existing systems and to prototype new ones and to formalize the link between objective and subjective image quality metrics. Therefore, the purpose of this project, was to contribute to adaptation and validation of an existing simulator for simulation of C-arm X-ray imaging. Firstly, the study of the existing simulation tool was performed to choose further development axes. Afterwards, preliminary estimations of simulation complexity by evaluating the number of photons for a given imaging examination were performed. Previous studies[1] showed the determining impact of focal spot on imaging performance (reducing the limiting spatial frequency in common examination conditions) of X-ray interventional imaging systems.  Therefore, the work focused on the improvements of source model, in particular realistic focal spot was defined and simulations of images with close-to-real sharpness were performed and compared to experimentally acquired images. Finally, a part of this project was dedicated to scatter study. An experimental set-up and "scatter map" analysis were designed to determine the scatter evolution as function of imaging field-of-view.  First simulations were also performed. [1] Samei, E., Ranger, N., MacKenzie, A., Honey, I., Dobbins, J. and Ravin, C. (2008). Detector or System? Extending the Concept of Detective Quantum Efficiency to Characterize the Performance of Digital Radiographic Imaging Systems 1. Radiology, 249(3), pp.926-937.

Made available in DSpace on 2017-07-21T14:19:42Z (GMT). No. of bitstreams: 1 Luiz Gustavo Barros.pdf: 2755823 bytes, checksum: bca8719768cf3309de85ec488ed781ee (MD5) Previous issue date: 2013-08-22 / Images acquired in the field with ordinary cameras, tend to have a lower quality compared with those obtained in the laboratory, including noise and unclear areas. This paper proposes a methodology for the analysis of sharpness in wood images of wood to analyze its impact on their classification. To evaluate this proposal, a database of wood images was used and each sample has extracted its color and texture characteristics using uniform local binary pattern and RGB color model methods, respectively. The Tenengrad method was used to evaluate the image sharpness and then the images were classified as high or low sharpness. Scenarios were developed to test the impact of the analysis of sharpness and check how it contributes to the hit rate. / Imagens adquiridas em campo, com câmeras comuns, tendem a possuir uma qualidade inferior se comparadas com as adquiridas em laboratório, incluindo ruídos e áreas pouco nítidas. Partindo dessa premissa, nesse trabalho foi proposta uma metodologia para a análise de nitidez em imagens de madeira para analisar seu impacto na classificação das mesmas. Para avaliar essa proposta, foi utilizada uma base de dados de imagens de madeira e extraídas características de cor e textura através dos métodos LBP Uniforme e RGB, respectivamente. O método Tenengrad foi utilizado para avaliar a nitidez das imagens e através dele as imagens foram classificadas alta e baixa nitidez. Foram elaborados cenários para testar o impacto da análise de nitidez e verificar de que forma a mesma contribui com a taxa de acerto.

Esta tese ocupa-se da investigação da semiótica da agudeza, utilizando como corpus poemas do final do século XX, chamados neobarrocos, e fragmentos de Galáxias, de Haroldo de Campos, e Finnegans1Wake, de James Joyce. As recepções contemporâneas aos séculos XVI e XVII não entendem as produções literárias como barrocas, mas como clássicas, diferentemente, portanto, do valor atribuído ao estado de barroco constante dos textos da crítica do século XX. Da investigação das obras de Peregrini, Gracián, Hansen e Pécora, depreende-se a agudeza como sistematizadora das produções barrocas dos seiscentos. Além disso, esta pesquisa constata não a presença eufórica de barroco sincrônico ou a existência de um possível neobarroco, mas gradações da agudeza como um operador formal da poesia dita barroquista. Com base nessa agudeza, propõe-se, dentro do quadro teórico-metodológico da semiótica tensiva, demonstrar como essa poesia, vista por muitos críticos como neobarroca, é regida segundo uma oscilação que a regula, reconhecendo nela uma dominância de agudeza do plano da expressão (PE) e/ou uma dominância de agudeza do plano do conteúdo (PC). Observadas as propriedades da agudeza, os objetos poéticos apresentam diferenças tensivas que os encaminham para uma poesia que conhece a graduação entre mais fluida e mais nítida, manifestando diferenças de acentuação no obscurecimento formal do enunciado. O enunciador, ao privilegiar a vivificação das agudezas, promove uma tensão estetizante: um jogo entre o rápido prazer da conservação sensível e o demorado prazer do reconhecimento inteligível do objeto estético, dois tipos diferentes de fruição. Dividida em cinco capítulos, a tese aborda inicialmente a ausência e a presença do recorte de barroco nos estudos literários, bem como a dominância do sobrevir nos semas de barroco e a sincronia e diacronia dos estados de barroco em direção a uma agudeza idiossincrônica. Em seguida, examina o jogo tensivo entre agudeza da expressão e agudeza do conteúdo, focalizando sobretudo os tratadistas seiscentistas e as propriedades da agudeza. Ocupa-se também da negação da euforia barroquista em direção à visualidade na poesia da agudeza. Como o conceito de neobarroco varia de autor para autor, examina-se o ponto de vista de Umberto Eco, Omar Calabrese, Severo Sarduy, Lezama Lima, Alejo Carpentier, Haroldo de Campos, Affonso Ávila, Affonso Romano SantAnna, Horácio Costa, Ana Hatherly, Ivan Teixeira, para estabelecer um modelo mais conforme à semiótica tensiva. A tese trata ainda dos limites entre sensível e inteligível na poesia aguda do século XX, realizando uma recapitulação da fenomenologia em diálogo com a semiótica tensiva, da qual sobressai o conceito de fé perceptiva e de perobjeto zilberberguiano. Finalmente, entra em cena a agudeza do final do século XX na direção do objeto fluido. / This thesis is concerned with the investigation of semiotics of sharpness. Its corpus consists of poems from the late 20th century which are called \"neo-baroque\", and fragments of Haroldo de Campos Galáxias and James Joyces Finnegans Wake. Contemporary receptions to the sixteenth and seventeenth centuries do not understand the literary productions as baroque, but as classical, therefore unlike the value assigned to the \"state of baroque\" in critical texts of the 20th century. Sharpness is inferred from the research of the works of Peregrini, Gracián, Hansen and Pécora as systematizing baroque productions of the 1600s. Furthermore, this research finds not the euphoric presence of synchronous baroque or the existence of a possible neo-baroque but gradations of sharpness as a formal operator of the so-called baroqueist poetry. Based on this sharpness, and within the theoretical and methodological framework of tensive semiotics, it is proposed to demonstrate how this poetry, regarded by many critics as \"neo-baroque\", is governed according to an oscillation that regulates it, recognizing in it a sharpness dominance of the level of expression (PE plano da expressão) and / or a sharpness dominance of the level of content (PC plano do conteúdo). Once observed the properties of sharpness, poetic objects show tensive differences that forward them for a poetry that knows the graduation from more fluent to more clear, manifesting differences of emphasis in the formal obscuration of the enunciation. The enunciator, while privileging the enlivenment of sharpness, promotes aesthetic tension: a game between the quick pleasure of sensitive conservation and delayed enjoyment of intelligible recognition of the aesthetic object two different types of enjoyment. Divided into five chapters, the thesis first addresses the absence and the presence of baroque slice in literary studies as well as the dominance of occurrence in baroque units of meaning and the synchrony and diachrony of baroque states towards an idiosynchronic sharpness. Then it examines the tensive game between sharpness of expression and sharpness of content, particularly focusing on the seventeenth-century treatise writers and the properties of sharpness. It also deals with the denial of baroqueist euphoria towards the visuality in the poetry of sharpness. As the concept of \"neo-baroque\" varies from author to author, the thesis examines the viewpoint of Umberto Eco, Omar Calabrese, Severo Sarduy, Lezama Lima, Alejo Carpentier, Haroldo de Campos, Alfonso Ávila, Affonso Romano Sant\'Anna, Horácio Costa, Ana Hatherly, Ivan Teixeira, in order to establish a model more consistent with tensive semiotics. It also addresses the boundaries between sensible and intelligible in the sharp poetry of the 20th century, making a recapitulation of phenomenology in a dialogue with tensive semiotics, from which the concepts of perceptual faith and zilberbergian perobject stand out. Finally, the sharpness of the late 20th century comes into play towards the fluid object.

Esta tese ocupa-se da investigação da semiótica da agudeza, utilizando como corpus poemas do final do século XX, chamados neobarrocos, e fragmentos de Galáxias, de Haroldo de Campos, e Finnegans1Wake, de James Joyce. As recepções contemporâneas aos séculos XVI e XVII não entendem as produções literárias como barrocas, mas como clássicas, diferentemente, portanto, do valor atribuído ao estado de barroco constante dos textos da crítica do século XX. Da investigação das obras de Peregrini, Gracián, Hansen e Pécora, depreende-se a agudeza como sistematizadora das produções barrocas dos seiscentos. Além disso, esta pesquisa constata não a presença eufórica de barroco sincrônico ou a existência de um possível neobarroco, mas gradações da agudeza como um operador formal da poesia dita barroquista. Com base nessa agudeza, propõe-se, dentro do quadro teórico-metodológico da semiótica tensiva, demonstrar como essa poesia, vista por muitos críticos como neobarroca, é regida segundo uma oscilação que a regula, reconhecendo nela uma dominância de agudeza do plano da expressão (PE) e/ou uma dominância de agudeza do plano do conteúdo (PC). Observadas as propriedades da agudeza, os objetos poéticos apresentam diferenças tensivas que os encaminham para uma poesia que conhece a graduação entre mais fluida e mais nítida, manifestando diferenças de acentuação no obscurecimento formal do enunciado. O enunciador, ao privilegiar a vivificação das agudezas, promove uma tensão estetizante: um jogo entre o rápido prazer da conservação sensível e o demorado prazer do reconhecimento inteligível do objeto estético, dois tipos diferentes de fruição. Dividida em cinco capítulos, a tese aborda inicialmente a ausência e a presença do recorte de barroco nos estudos literários, bem como a dominância do sobrevir nos semas de barroco e a sincronia e diacronia dos estados de barroco em direção a uma agudeza idiossincrônica. Em seguida, examina o jogo tensivo entre agudeza da expressão e agudeza do conteúdo, focalizando sobretudo os tratadistas seiscentistas e as propriedades da agudeza. Ocupa-se também da negação da euforia barroquista em direção à visualidade na poesia da agudeza. Como o conceito de neobarroco varia de autor para autor, examina-se o ponto de vista de Umberto Eco, Omar Calabrese, Severo Sarduy, Lezama Lima, Alejo Carpentier, Haroldo de Campos, Affonso Ávila, Affonso Romano SantAnna, Horácio Costa, Ana Hatherly, Ivan Teixeira, para estabelecer um modelo mais conforme à semiótica tensiva. A tese trata ainda dos limites entre sensível e inteligível na poesia aguda do século XX, realizando uma recapitulação da fenomenologia em diálogo com a semiótica tensiva, da qual sobressai o conceito de fé perceptiva e de perobjeto zilberberguiano. Finalmente, entra em cena a agudeza do final do século XX na direção do objeto fluido. / This thesis is concerned with the investigation of semiotics of sharpness. Its corpus consists of poems from the late 20th century which are called \"neo-baroque\", and fragments of Haroldo de Campos Galáxias and James Joyces Finnegans Wake. Contemporary receptions to the sixteenth and seventeenth centuries do not understand the literary productions as baroque, but as classical, therefore unlike the value assigned to the \"state of baroque\" in critical texts of the 20th century. Sharpness is inferred from the research of the works of Peregrini, Gracián, Hansen and Pécora as systematizing baroque productions of the 1600s. Furthermore, this research finds not the euphoric presence of synchronous baroque or the existence of a possible neo-baroque but gradations of sharpness as a formal operator of the so-called baroqueist poetry. Based on this sharpness, and within the theoretical and methodological framework of tensive semiotics, it is proposed to demonstrate how this poetry, regarded by many critics as \"neo-baroque\", is governed according to an oscillation that regulates it, recognizing in it a sharpness dominance of the level of expression (PE plano da expressão) and / or a sharpness dominance of the level of content (PC plano do conteúdo). Once observed the properties of sharpness, poetic objects show tensive differences that forward them for a poetry that knows the graduation from more fluent to more clear, manifesting differences of emphasis in the formal obscuration of the enunciation. The enunciator, while privileging the enlivenment of sharpness, promotes aesthetic tension: a game between the quick pleasure of sensitive conservation and delayed enjoyment of intelligible recognition of the aesthetic object two different types of enjoyment. Divided into five chapters, the thesis first addresses the absence and the presence of baroque slice in literary studies as well as the dominance of occurrence in baroque units of meaning and the synchrony and diachrony of baroque states towards an idiosynchronic sharpness. Then it examines the tensive game between sharpness of expression and sharpness of content, particularly focusing on the seventeenth-century treatise writers and the properties of sharpness. It also deals with the denial of baroqueist euphoria towards the visuality in the poetry of sharpness. As the concept of \"neo-baroque\" varies from author to author, the thesis examines the viewpoint of Umberto Eco, Omar Calabrese, Severo Sarduy, Lezama Lima, Alejo Carpentier, Haroldo de Campos, Alfonso Ávila, Affonso Romano Sant\'Anna, Horácio Costa, Ana Hatherly, Ivan Teixeira, in order to establish a model more consistent with tensive semiotics. It also addresses the boundaries between sensible and intelligible in the sharp poetry of the 20th century, making a recapitulation of phenomenology in a dialogue with tensive semiotics, from which the concepts of perceptual faith and zilberbergian perobject stand out. Finally, the sharpness of the late 20th century comes into play towards the fluid object.

Esta tese se propõe examinar a poesia de John Donne (1572-1631) na perspectiva de um âmbito mais amplo de práticas representativas dos meios letrados das cortes do século XVII. Pressupondo a vigência de uma instituição retórica cujos preceitos condicionavam a prática poética, adota-se uma metodologia de pesquisa que flexibiliza os limites classificatórios da historiografia oitocentista posteriormente impostos aos poetas do século XVII. Assim, procede-se a uma análise retórico-poética da poesia de Donne, particularmente, mas também de seus coetâneos George Chapman, Fulke Greville, William Shakespeare e outros considerando os gêneros e estilos de suas composições, as espécies de agudeza que efetuavam, a adequação dos conceitos que formulavam como ornato dialético enigmático e a legibilidade que constituíam nas obras. Propõe-se uma investigação dos pressupostos doutrinários vigentes na época que significam as práticas representativas e as categorias que a envolvem, como a conceituação de que a poesia vernacular culta se define como prática de emulação da poesia greco-latina em seu elenco de autoridades; de que a preceituação vernacular analogamente se define como prática de emulação da preceitução antiga em seus postulados diversos; que a prática de emulação é ativa e não pressupõe cópia servil, mas variação dos argumentos de um mesmo lugar de invenção e variação do tópico elocutório, assumindo a versatilidade das operações retórico-poéticas como prova de engenho e arte. Tendo como força determinante a valoração do wit (engenho; ingenio; ingegno) nos meios letrados do século XVII, esta tese considera sempre que pode as práticas poéticas e preceptivas continentais, cruzando-as com suas contrapartes inglesas, buscando definir os critérios variados de recepção da poesia e os preceitos em uso que constituem a poética da agudeza. / This Ph.D. thesis examines the poetry of John Donne (1572-1631) in the light of the representative practices in the learned circles of 17th century courts. Presuming that there was an effective presence of a rhetorical institution at that time, which conditioned poetical production, I have adopted a critical methodology that displaces the classificatory limits of 19th century historiography later imposed on the poets of the early 17th century. I have specifically made a rhetorical-poetical analysis of the poetry of Donne, but also of George Chapman, Fulke Greville, William Shakespeare and others, considering the genres and the styles of their composition, the types of wit they used, the aptness of the conceits formulated as enigmatic dialectical ornaments, and the legibility of their works. I have also investigated the doctrinal conjectures current at the time which then signified the representative practices, such as the concept that cultivated vernacular poetry was defined as an emulation of Greek and Latin poetry; that the vernacular doctrines of rhetoric were also defined as emulation of ancient doctrines; and that the practice of emulation was an active force, and did not imply servile imitation, but rather a variation of the places of argument and the elocutory topic, taking on the diversity of rhetorical and poetical procedures as proof of wit and art. Taking as a determining force the value given to wit (engenho; ingenio; ingegno) in the learned circles of the early 17th century, this thesis also takes into consideration continental poetical and rhetorical practices, cross-examining them with English ones, in an attempt to define the diverse criteria of poetry reception and the precepts then extant which ultimately constituted the poetics of wit.