Sistemas diferenciais quadráticos planares estão presentes em muitas áreas da matemática aplicada. Embora mais de mil artigos tenham sido publicados sobre os sistemas quadráticos ainda resta muito a se conhecer sobre esses sistemas. Problemas clássicos, e em particular o XVI problema de Hilbert, estão ainda em aberto para essa família. Um dos objetivos dos pesquisadores contemporâneos é obter a classificação topológica completa dos sistemas quadráticos. Devido ao grande número de parâmetros (essa família possui doze parâmetros e, aplicando transformações afins e reescala do tempo, reduzimos esse número a cinco, sendo ainda um número grande para se trabalhar) usualmente subclasses são consideradas nas investigações realizadas. Quando características específicas são levadas em consideração, o número de parâmetros é reduzido e o estudo se torna possível. Nesta tese estudamos principalmente duas subfamílias de sistemas quadráticos: a primeira possuindo um nó triplo semielemental e a segunda possuindo uma selanó semi elemental finita e uma selanó semielemental infinita formada pela colisão de uma sela infinita com um nó infinito. Os diagramas de bifurcação para ambas as famílias são tridimensionais. A família tendo um nó triplo gera 28 retratos de fase topologicamente distintos, enquanto o fecho da família tendo as selasnós dentro do espaço de bifurcação de sua forma normal gera 417. Polinômios invariantes são usados para construir os conjuntos de bifurcação e os retratos de fase topologicamente distintos são representados no disco de Poincaré. Os conjuntos de bifurcação são a união de superfícies algébricas e superfícies cuja presença foi detectada numericamente. Ainda nesta tese, apresentamos todos os retratos de fase de um sistema diferencial conhecido como modelo do tipo SIS (sistema suscetívelinfectadosuscetível, muito comum na matemática aplicada) e a classificação dos sistemas quadráticos possuindo hipérboles invariantes. Ambos sistemas foram investigados usando de polinômios invariantes afins. / Planar quadratic differential systems occur in many areas of applied mathematics. Although more than one thousand papers have been written on these systems, a complete understanding of this family is still missing. Classical problems, and in particular Hilberts 16th problem, are still open for this family. One of the goals of recent researchers is the topological classification of quadratic systems. As this attempt is not possible in the whole class due to the large number of parameters (twelve, but, after affine transformations and time rescaling, we arrive at families with five parameters, which is still a large number), many subclasses are considered and studied. Specific characteristics are taken into account and this implies a decrease in the number of parameters, which makes possible the study. In this thesis we mainly study two subfamilies of quadratic systems: the first one possessing a finite semielemental triple node and the second one possessing a finite semielemental saddlenode and an infinite semielemental saddlenode formed by the collision of an infinite saddle with an infinite node. The bifurcation diagram for both families are tridimensional. The family having the triple node yields 28 topologically distinct phase portraits, whereas the closure of the family having the saddlenodes within the bifurcation space of its normal form yields 417. Invariant polynomials are used to construct the bifurcation sets and the phase portraits are represented on the Poincaré disk. The bifurcation sets are the union of algebraic surfaces and surfaces whose presence was detected numerically. Moreover, we also present the analysis of a differential system known as SIS model (this kind of systems are easily found in applied mathematics) and the complete classification of quadratic systems possessing invariant hyperbolas.

L’objet de cette thèse est la représentation en ronde-bosse des souverains et particuliers du Moyen Empire tardif et de la Deuxième Période Intermédiaire (mi-XIIe à fin-XVIIe dynastie, 1850-1550 av. J.-C). Ces trois siècles forment un ensemble cohérent du point de vue du système politique, très bureaucratique, du point de vue de la culture matérielle (pratiques funéraires, production de stèles et de statues) et de celui des sources textuelles. L’intérêt du choix de cette période réside dans l’abondance du répertoire conservé, qui permet de mener des analyses approfondies et de procéder à des comparaisons précises entre l’image du roi et celle des particuliers de différents niveaux sociaux. Cette période est également suffisamment longue pour permettre d’établir une évolution des tendances observées. La particularité de cette thèse est de considérer la statuaire royale et privée comme un ensemble. L’objectif consiste à renouveler la grille d’analyse d’une des productions majeures de la société égyptienne. <p>1480 pièces figurent au catalogue, dont beaucoup sont inédites :330 statues royales et 1150 statues privées. Ce répertoire a été constitué sur base des publications (catalogues de musées, d’expositions, de vente, rapports de fouilles) et à partir de l’examen personnel des pièces conservées dans 65 musées à travers l’Europe, les États-Unis, l’Égypte et le Soudan, dans des collections privées, ainsi que sur les sites archéologiques. Ce vaste catalogue permet de dresser un panorama aussi complet que possible de la statuaire de l’époque envisagée. <p>La statuaire est un moyen pour l’Égyptien de l’Antiquité, grâce à la nature performative de l’art, de matérialiser sa présence dans les sanctuaires, de se trouver face aux divinités, de leur faire don d’offrandes en échange de leurs bienfaits, de rendre hommage à des prédécesseurs. C’est aussi une façon d’exprimer un message par le choix du matériau, du type statuaire, d’une physionomie et d’un emplacement dans un temple, une chapelle ou une tombe. C’est ce discours que pouvaient lire les contemporains du titulaire de la statue et qu’il appartient au chercheur de démêler. Je me suis employé à définir qui étaient les destinataires des statues, quelle était la clientèle concernée, à quel endroit on plaçait ces statues (régions, contextes architecturaux, programmes iconographiques), quel était le sens et la fonction que pouvaient avoir la forme d’une statue, ses dimensions, la position et la gestuelle du personnage représenté. J’ai examiné les différents matériaux utilisés, les raisons de leur choix, leurs significations particulières, les ateliers auxquels ils étaient associés. J’ai établi le rapport entre la physionomie du souverain et celle des particuliers, ainsi que le développement stylistique de la statuaire au cours des trois siècles envisagés, et tenté d’interpréter les différents critères de cette évolution. En bref, j’ai cherché à définir le rôle et l’usage d’une statue, le but de son acquisition et de son installation, le message qu’elle véhiculait.<p>Les statues du souverain traduisent une volonté d’être présent partout, dans les divers temples et sanctuaires, de regarder et d’être vu, de rester présent au-delà de la mort, à la fois dans le monde des dieux, et sur terre, parmi les hommes. Elles servent aussi de réceptacle au culte du souverain dès son vivant et remplissent le rôle d’intercesseurs entre les hommes et les dieux. Enfin, elles commémorent le passage d’expéditions sur les sites éloignés et sacrés. <p>Le message inhérent à la statuaire privée est différent. Les particuliers ne sont pas quant à eux d’essence divine et n’incarnent pas la maîtrise du monde dans la personne d’un être surhumain. Les dignitaires sont des individus et représentés comme tels, à la différence le roi, qui est roi avant d’être un homme. La statuaire privée exprime, par le pouvoir de l’image, du costume, de la nature de la pierre, le rang privilégié d’un humain parmi ses semblables, le désir d’afficher un haut statut et une proximité avec le souverain. Le personnage représenté par une statue acquiert le moyen d’être intégré dans le temple, de jouir du culte et des offrandes. Par le moyen des titres étalés dans les inscriptions de la statue, par le choix de matériaux prestigieux et par le recours aux ateliers royaux, qui leur fournissent des statues dont la physionomie est en tout point similaire à celle du souverain, les hauts dignitaires manifestent leur allégeance au pouvoir et leur proximité avec le souverain. <p>Quant aux membres des niveaux plus modestes de l’élite, ils cherchent à exprimer un rang élevé par mimétisme vis-à-vis de ces hauts dignitaires, en adoptant les mêmes types statuaires, costumes et perruques, et, quand ils n’ont pas les moyens d’acquérir une statue dans un matériau prestigieux, en employant des roches qui peuvent en gagner l’aspect. Ces images ne reflètent pas la fonction précise des individus qu’elles représentent ;elles ont en revanche le pouvoir d’exprimer un statut, réel ou non, et accordent dans l’au-delà un rang privilégié à leurs titulaires, en servant d’intermédiaires entre les mondes humain et divin. <p>Ce travail permet d’apporter plusieurs voies de réflexion, à la fois sur l’époque envisagée et sur le domaine de la production sculpturale égyptienne en général. Cette étude ne cherche pas seulement à exploiter un large corpus de statues, mais à formuler un ensemble de questions pour obtenir une meilleure et plus vaste compréhension de tous les facteurs impliqués dans la production et l’usage de la statuaire, ainsi que des implications sociales qui y sont attachées. / Doctorat en Histoire, art et archéologie / info:eu-repo/semantics/nonPublished

Esta tese de doutorado apresenta um estudo e formulações teóricas sobre o conceito de espect-autoria e defende os conceitos de Poética da Autoria Aberta, Poética da Autoração e Poéticas em Coletividade como praxis artística de apropriação dos dispositivos de produção das representações sociais, no contexto da autoria dos espectadores nas artes participativas e interativas. Numa transferência interdisciplinar de conceitos a exemplo do conceito espect-autor de Gellouz (2007), o estudo propõe as noções de autorabilidade, obra autorável, agenciamento autoral do espectador e trinômio produção/recepção/produção bem como os conceitos formulados de função-espect-autor, espect-autor em coletividade, particip-autor, inter-autor e trans-autor, que privilegiam a noção de autoria em suas notações, configurando uma taxonomia mais apropriada para compor um vocabulário que permita designar e compreender a noção de espect-autoria, ou seja, a produção autoral dos espectadores, enquanto forma, repertório e significados, nas obras cuja abertura poética propõe desafios autorais aos seus espectadores. A principal referência artística e fonte desta pesquisa é a série Autorretrato Coletivo (1987-), um conjunto de obras participativas e interativas que eu proponho como repositório dialógico e polifônico da identidade coletiva, tendo como princípio a apropriação dos espectadores enquanto autores de suas identidades no corpus da obra. Em suma, a função-autor exercida pelos espectadores, mais precisamente a sua função-espect-autor, em processos de criação/co-criação ou recriação (por recombinação e/ou repertoriação) no contexto das artes participativas e interativas, tem profundas implicações para nossa compreensão da evolução da arte como um fenômeno coletivo. / This thesis presents a study and theoretical formulations about the concept of spect-authorship on participatory and interactive artworks and defends the concepts of Poetics of the Open Authorship, Authoring Poetics and Multi-Poetics in Collectivity as artistic praxis of apropriation of the production devices of the social representations in the context of the spectators authorship in the participatory and interactive arts. Through an interdisciplinary transfer of concepts as Gellouz concept of spect-author (2007) , this study proposes the notions of authorability, authoriable artwork, authorial agency of the spectator, trinomial production/reception/production as well the concepts of function-espect-author, spect-author in collectivity, particip-author, inter-author and trans-author, which privilege the notion of authorship, setting a taxonomy more appropriate to compose a vocabulary that describes and increases the understanding of the concept of spect-authorship, the authorial production of the spectators as form, repertory and meanings, in the artworks whose poetic openness proposes authorial challenges to their spectators. The main artistic reference and source of this research is the series Collective Self-Portrait (1987-), a set of participatory and interactive artworks that I propose as a dialogic and polyphonic repository of the collective identity, based on the principle of appropriation of the spectators as authors of their own identities in the corpus of the artwork. Summing up, the author-function experienced by the spectators, more precisely their spect-author-function, in creation/co-creation or recreation process in the context of participatory and interactive arts, holds profound implications for our understanding of art evolution as a collective phenomenon.

During the 16th century occurred a new phenomen, that the physically disabled people because of they visage were presented as curiosities or miracles. Some cases were so incredible therefore their appearances gave an impulse for creating an artwork. The images were popular between all social levels, were collected by townspeople, scientists, nobles and kings. The dissertation thesis "Homo deformis". The fascination by appearance of deformed human body in the Czech lands between 1526-1620 aims to explore how the phenomen of human curiosities was reflected in early modern visual art in the Czech lands. This dissertation thesis bases on individual examples of human monstrosity in various art forms as an portraits, allegories, scientific illustrations and pamphlets. It exams images of abnormal disabled people between 1526-1620 and focuses on they symbolic meaning, aesthetic interpretation. It summarizes the knowlege about perceptions of depicted abnormal persons in 16th century. It also shows the Early modern society reactions about "homo deformis", their everydayness and social status. This thesis studies reasons why the disabled body was a kind an inspiration for artists. It examines ii the artists of 16th century were able to picture cases of physicality deformed bodies anatomically correctly. It...

Using portraiture methodology and social practice theory, this study examined the identity work of young people engaged in a teen arts internship program at a contemporary arts center in post-Katrina New Orleans. This research asked four interrelated questions. Through the lens of a teen arts internship at a contemporary arts center in post-Katrina New Orleans, 1) How do contextual figured worlds influence artist identity work? 2) How does artist identity work manifest through personal narratives? 3) How does artist identity work manifest in activities? 4) What are the consequences of artist identity work? The findings of the study highlight how sociocultural factors influence dis/identification with the visual arts in young people and provoke considerations of in/equity in the arts.

Die Fotografien in dem Album des Sächsischen Landtags von 1873 zeigen zahlreiche bis heute bekannte sächsische Abgeordnete. Das in Samt eingebundene Prachtfotoalbum wurde von den Abgeordneten der zweiten Kammer des sächsischen Landtages an ihren Kollegen Christian Gottlieb Riedel anlässlich seines 25-jährigen Landtagsjubiläum überreicht.

Abstract This study concerns the Swedish artist Roj Friberg (1934–2016). The essay is based on a study of technique and materiality used by Friberg. He is quite marginalized and slightly forgotten in the Swedish art history and when mentioned merely described as a painter from the 1960´s who used graphite mixed with French turpentine, in order to work on the surface with an eraser attached to an electric drill. However, Friberg used other different and more complex painting techniques in his work, something this essay will notice and highlight. The used method is a biographical, dealing with the references to Friberg. To explain why he was considered an “outsider” in Swedish art, the theory of social capital by Pierre Bourdieu is applied. Also, Wolfgang Kemps concept of reception history, which focus on the arts beholder, rather than the artists itself. From the middle of 1970 Friberg also used an ancient painting technique called encaustic, heated beeswax mixed with pigment. Paintings which have received very little attention; therefore, the focus is on his use of encaustic in combination with his other techniques, such as melted graphite, melted wax crayons or drawn with wax crayons and graphite. The work with lasered layers and the typical method of working from darkness to light in Friberg´s pictures shows resemblance with the ancient encaustic portraits from Fayum, in the 50 AD.

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This empirical and theological research investigates the self-conception of the east-german women in the Brethren Movement, in order to discover by which role model they predominantly orientated themselves. Therefore women were interviewed, who are – on one hand – socialised in the Brethren Movement, and on the other hand have partly realized the GDR role model through working in a typically male business and/or in a leading position. It was possible to describe in that study three contrasting typologies. On that foundation, thesis and conclusions were drawn for the development of identity and the operation of the church. This project wants to make a contribution to the investigation of the –almost untouched academically – field of the women in the Brethren Movement. At the same time it should serve as an historical example in how the church dealt with changing role models. / In dieser Forschungsarbeit wird das Selbstverständnis der ostdeutschen Frauen in der Brüderbewegung empirisch-theologisch untersucht, um herauszufinden, an welchem der beiden divergierenden Rollenbilder (DDR-Gesellschaft oder Brüderbewegung) sich diese Frauen stärker orientieren. Dazu wurden Frauen interviewt, die einerseits in der Brüderbewegung sozialisiert sind, und andererseits durch ihre Berufstätigkeit in einem männertypischen Beruf und/oder in Leitungspositionen das DDR-Rollenbild teilweise umgesetzt haben. Im Verlauf dieser Studie ließen sich drei kontrastierende Typologien von Selbstbildern erkennen. Auf dieser Grundlage wurden Schlussfolgerungen und Thesen über die Identitätsfindung der Frauen und ihre gelebte Gemeindepraxis gezogen. Mit der Betrachtung der Frauen in den Brüdergemeinden will diese qualitative Studie einen Beitrag dazu leisten, neue Erkenntnisse aus einem wissenschaftlich bisher kaum erforschten Gebiet zu gewinnen. Gleichzeitig soll die vorliegende Studie anhand dieses historischen Beispiels den Umgang einer Gemeinde mit sich verändernden Rollenbildern zeigen. / Christian Spirituality, Church History and Missiology / M. Th. (Missiology)

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