Electronic Portal Image Devices (EPID) são dispositivos eletrônicos que foram criados originalmente para aquisição de imagens portais. Atualmente eles também têm sido estudados para reconstrução de dose no plano do eixo central (paralelo ao EPID) na modalidade transit (modalidade que considera um material atenuador entre a fonte e o EPID). Neste trabalho foi determinado um algoritmo de reconstrução de dose para relacionar mapas bidimensionais de dose localizados dentro de geometrias que simularam uma situação clínica em radioterapia de forma simplificada. Para tal foram feitas simulações Monte Carlo utilizando o pacote de simulação PENELOPE de maneira que um cubo composto de água representou o corpo do paciente e um paralelepípedo retângulo composto de água representou o EPID. Definiu-se primeiramente a geometria controle e os parâmetros de irradiação controle e então foram feitas simulações para determinar a equação de reconstrução de dose referencial. Uma vez determinada essa equação, foram feitas novas simulações variando o tamanho de campo, espessura do objeto simulador do corpo, distância entre a fonte e a superfície de entrada do objeto simulador do corpo (DFS) e distância entre a superfície de saída do objeto simulador do corpo e o centro do objeto simulador do EPID (DSDE). Os arquivos de saída dessas simulações alimentaram o programa contendo o algoritmo de reconstrução de dose, feito em MATLAB®. Após a aplicação do programa, comparou-se a matriz que representa o mapa bidimensional localizado dentro do objeto simulador do corpo com a matriz localizada no mesmo local, reconstruída a partir da matriz que representa o objeto simulador do EPID. Os resultados encontrados neste trabalho mostram que a equação de reconstrução de dose e o algoritmo de reconstrução de dose propostos são válidos com desvios padrão menor que 1,6%. / Electronic Portal Image Devices (EPID) were originally created to acquire portal images, but they have also been studied for dose reconstruction in the central axis plane (parallel to the EPID) in transit mode (mode which considers an attenuator material between the source and the EPID). In this work we determined a dose reconstruction algorithm that relate two-dimensional dose maps located within geometries that simulated a clinical situation in simplified form. For this, simulations were performed using the simulation package PENELOPE so that a cube composed of water represented the patients body and a rectangle parallelepiped composed of water represented the EPID. We defined a control geometry and control irradiation parameters first, then simulations were performed to determine the referential dose reconstruction equation. Once determined this equation, new simulations were performed varying the field size, the body phantom thickness, the distance between the source and the body phantom entrance surface (DFS) and the distance between the body phantom exit surface and the EPID phantom center. The output files of these simulations fed the program containing the dose reconstruction algorithm, wrote in MATLAB®. After the program application, we compared the matrix that represents the two-dimensional map located within the body phantom with the matrix located at the same site, reconstructed from the matrix that represents the EPID phantom. The results in this work show that the dose reconstruction equation and the dose reconstruction algorithm proposed are valid with less than 1,6% standard deviation.

A radiocirugia estereotáxica é uma técnica que fornece altas doses de radiação utilizando campos pequenos para conformação da dose no volume alvo do tratamento. Devido à complexidade desta técnica torna-se necessária a verificação da distribuição de dose no volume de tratamento. Neste trabalho, as distribuições tridimensionais (3D) de doses de casos clínicos de neoplasias cranianas foram estudadas utilizando-se um objeto simulador de cabeça. A reconstrução das distribuições de doses nos volumes alvo e nas regiões adjacentes a estes foram avaliadas com o código de simulação PENELOPE, o dosímetro MAGIC-f gel e com o sistema de planejamento iPlan. Filmes radiocrômicos também foram empregados para a determinação das distribuições de dose em planos do tratamento. As respostas obtidas com as ferramentas dosimétricas utilizadas foram analisadas através de distribuições de índices gama, comparando-se os mapas centrais das distribuições de dose obtidas com as quatro ferramentas dosimétricas utilizadas. Usando-se critérios de tolerância de 3% e 3mm, a análise realizada na região da prescrição de dose (isodoses de 95%) mostrou-se equivalente para todas as ferramentas dosimétricas utilizadas; resultado diferente foi observado para isodoses menores, com uma equivalência máxima de 76,5%. As distribuições volumétricas, obtidas através do PENELOPE, MAGIC-f gel e o iPlan, foram comparadas, ainda, através dos histogramas dose-volume, para cada caso estudado, mostrando que 95% da dose absorvida relativa encontra-se dentro do volume alvo para todos os planos estudados. A probabilidade de controle tumoral, TCP, foi avaliada para os casos de radiocirurgia estudados, a partir das distribuições volumétricas de dose, resultando em uma probabilidade de controle tumoral máxima de 72%, para todos os casos, conforme o modelo matemático de TCP utilizado. Das comparações realizadas pode-se inferir que o dosímetro MAGIC-f gel e o código de simulação PENELOPE-Monte Carlo podem ser utilizados para determinar as distribuições de dose em 3D para a técnica de radiocirurgia estereotáxica. Essas ferramentas dosimétricas podem, dessa forma, auxiliar no comissionamento de unidades de terapia e em verificações 3D de doses do tratamento dos pacientes, permitindo avaliações dentro e ao redor do volume alvo e podendo se tornar ferramentais de rotina nos serviços de radioterapia. / Stereotactic radiosurgery is a technique which delivers high radiation doses using small fields to conform the absorbed dose into the target volume. Due to the complexity of this technique it is necessary to verify the dose distribution in the treatment volume. Thus, in this study the three-dimensional (3D) dose distributions of selected clinical cases of cranial tumors were obtained using a head phantom. The the dose distributions of target volumes and adjacent regions were evaluated with PENELOPE Monte Carlo simulation code, MAGIC-f dosimeter and iPlan® treatment planning system. Radiochromic films were also used to determine the dose distribution on selected plans of the treatment. The obtained results for the proposed dosimetric tools were analyzed by the gamma index distributions, comparing the maps of the central dose distributions obtained with the four dosimetric tools. Using the dose criteria of 3% in 3 mm, the gamma index test showed equivalence in the region of dose prescription (95% isodose) and a different result was observed for lower isodoses, with maximum accordance of 76.5%. The volumetric dose distributions obtained with PENELOPE, MAGIC-f and iPlan were also compared using the dose-volume histograms for each studied case, showing that 95% of the absorbed dose yield within the target volume. The tumor control probability, TCP, was evaluated for the studied radiosurgery cases, from the dose distributions-volumetric, resulting in a maximum probability of tumor control of 72% for all cases, for the used mathematical model of TCP. From the results it can be inferred that the MAGIC-f gel dosimeter and the PENELOPE Monte Carlo simulation code can be used to determine 3D dose distributions for stereotactic radiosurgery. These dosimetric tools can assist the commissioning of treatment units and 3D dose verifications of patients treatments, allowing assessments in and around the target volume and may become routine in radiotherapy services.

Ο PENELOPE αποτέλει σήμερα έναν ιδιαίτερα διαδεδομένο κώδικα στον τομέα της φυσικής αλληλεπιδράσεων φωτονίων και ηλεκτρονίων με την ύλη. Τα χαρακτηριστικά του είναι τέτοια, ώστε να είναι αρκετά προσαρμόσιμος κώδικας Μόντε Κάρλο σε προβλήματα ακτινοφυσικής και ιδιαίτερα προβλήματα ακτινοθεραπευτικής δοσιμετρίας και ακτινοθεραπευτικής ογκολογίας. Ο αρχικός σκοπός αυτής της διπλωματικής εργασίας, ήταν να καταστεί αρχικά εκτελέσιμος ο κώδικας, να γίνει μια διερεύνηση των χαρακτηριστικών και των δυνατοτήτων του, και τέλος να χρησιμοποιηθεί για την πραγματοποίηση μιας σειράς απλών προσομοιώσεων σχετιζόμενες με την ακτινοθεραπευτική ογκολογία. / Simulations using Monte Carlo code, PENELOPE, in Radiation Oncology.

A Dissertation submitted to the Faculty of Arts, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Arts in Fine Arts. / American critic Hal Foster argues that conceptions of 'the natural' are not universal, they are historically and discursively produced, There is no unmediated presence of 'the natural' in painting. He proposes 'denaturalization' as a form of critical postmodemist aesthetic which questions universalist tendencies in contemporary cultural production" This research examines selected theories and visual. representations of 'the natural' in order to explore different ways in which Foster's notion of denaturalization may be productive in assessing the complexity of critical visual art practice in South Africa. My approach to the topic is largely fragmentary in order to reflect on and engage with the diverse terms of 'the natural' as manifest in visual art practice. To this end I discuss selected works of contemporary South African artists William Kentridge and Penelope'Siopis, While Foster's notion of denaturalization is productive in trying to engage with"critical issues' of art practice it is difficulr, if not impossible to determine if cenaln works conform with either his notion of a postmodernism of resistance or postmodernism of reaction. I will also explore the notion of denaturalization with reference to my practical work. / Andrew Chakane 2018

As a contribution to the emerging field of practice-based research in the arts, this thesis aims to activate space, experience and the concept in-between. As the in-between cannot be defined ahead of the rhythmic process it carries out and of which it is a part – a rhythm inherent in the city itself and in knowledge production – it is necessary to produce rhythmic relations between bodies, sites and concepts. An art experiment, a forty-two meter high swing mounted on the bridge, Älvborgsbron, in Gothenburg harbour, Sweden, serves as the point of entry to the thesis. A dancer in the swing moved slowly between the bridge and the ground, captured in a rhythmic experience of being earthbound and then weightless. The swing project, together with other rhythmic processes such as walking, weaving and acting physics, activate spatial, temporal and theoretical dimensions of the in-between. Merging my roles as an artist, teacher and researcher by pragmatic production, perception and concepts it becomes possible to transform the rhythms between the examples:   1. A swing mounted on a bridge; one of my art projects. 2. Walking and mapping strategies; as developed in my courses taught at the School of Architecture. 3. The myth about Penelope weaving. 4. Rhythmic relations between bodies and machines at CERN, the particle physics laboratory outside Geneva, a place that is important for several of my art projects.   Creative production aims to expand the capacity of the body.  By employing a bridging structure, spaces in-between are activated thus revealing the power and danger in-between. In that production collective processes merge, creating “social and collective machines” and another reality between:   1. bridge/swing/dancer, 2. map/walking/site, 3. war/loom/weaving, 4. theory/detector/bodies.   These rhythmic processes oscillate between representation and the complex forces of daily activities. However, it is not the rhythm itself that activates spaces in-between but, rather, the changing of directions of the rhythm: from moving to be in motion; from walking forward to walking and falling; from weaving cloth to producing time; from doing physics to acting physics. Activating in-between spaces means activating differences and another way of producing knowledge, a well-known strategy in contemporary art: a production of potential realities, in a constant interaction between concepts and spatial transformations. / QC 20100909

Els programes de simulació Monte Carlo de caràcter general s'utilitzen actualment en una gran varietat d'aplicacions.Tot i això, els models geomètrics implementats en la majoria de programes imposen certes limitacions a la forma dels objectes que es poden definir. Aquests models no són adequats per descriure les superfícies arbitràries que es troben en estructures anatòmiques o en certs aparells mèdics i, conseqüentment, algunes aplicacions que requereixen l'ús de models geomètrics molt detallats no poden ser acuradament estudiades amb aquests programes.L'objectiu d'aquesta tesi doctoral és el desenvolupament de models geomètrics i computacionals que facilitin la descripció dels objectes complexes que es troben en aplicacions de física mèdica. Concretament, dos nous programes de simulació Monte Carlo basats en PENELOPE han sigut desenvolupats. El primer programa, penEasy, utilitza un algoritme de caràcter general estructurat i inclou diversos models de fonts de radiació i detectors que permeten simular fàcilment un gran nombre d'aplicacions. Les noves rutines geomètriques utilitzades per aquest programa, penVox, extenen el model geomètric estàndard de PENELOPE, basat en superfícices quàdriques, per permetre la utilització d'objectes voxelitzats. Aquests objectes poden ser creats utilitzant la informació anatòmica obtinguda amb una tomografia computeritzada i, per tant, aquest model geomètric és útil per simular aplicacions que requereixen l'ús de l'anatomia de pacients reals (per exemple, la planificació radioterapèutica). El segon programa, penMesh, utilitza malles de triangles per definir la forma dels objectes simulats. Aquesta tècnica, que s'utilitza freqüentment en el camp del disseny per ordinador, permet representar superfícies arbitràries i és útil per simulacions que requereixen un gran detall en la descripció de la geometria, com per exemple l'obtenció d'imatges de raig x del cos humà.Per reduir els inconvenients causats pels llargs temps d'execució, els algoritmes implementats en els nous programes s'han accelerat utilitzant tècniques sofisticades, com per exemple una estructura octree. També s'ha desenvolupat un paquet de programari per a la paral·lelització de simulacions Monte Carlo, anomentat clonEasy, que redueix el temps real de càlcul de forma proporcional al nombre de processadors que s'utilitzen.Els programes de simulació que es presenten en aquesta tesi són gratuïts i de codi lliures. Aquests programes s'han provat en aplicacions realistes de física mèdica i s'han comparat amb altres programes i amb mesures experimentals.Per tant, actualment ja estan llestos per la seva distribució pública i per la seva aplicació a problemes reals. / Monte Carlo simulation of radiation transport is currently applied in a large variety of areas. However, the geometric models implemented in most general-purpose codes impose limitations on the shape of the objects that can be defined. These models are not well suited to represent the free-form (i.e., arbitrary) shapes found in anatomic structures or complex medical devices. As a result, some clinical applications that require the use of highly detailed phantoms can not be properly addressed.This thesis is devoted to the development of advanced geometric models and accelration techniques that facilitate the use of state-of-the-art Monte Carlo simulation in medical physics applications involving detailed anatomical phantoms. To this end, two new codes, based on the PENELOPE package, have been developed. The first code, penEasy, implements a modular, general-purpose main program and provides various source models and tallies that can be readily used to simulate a wide spectrum of problems. Its associated geometry routines, penVox, extend the standard PENELOPE geometry, based on quadric surfaces, to allow the definition of voxelised phantoms. This kind of phantoms can be generated using the information provided by a computed tomography and, therefore, penVox is convenient for simulating problems that require the use of the anatomy of real patients (e.g., radiotherapy treatment planning). The second code, penMesh, utilises closed triangle meshes to define the boundary of each simulated object. This approach, which is frequently used in computer graphics and computer-aided design, makes it possible to represent arbitrary surfaces and it is suitable for simulations requiring a high anatomical detail (e.g., medical imaging).A set of software tools for the parallelisation of Monte Carlo simulations, clonEasy, has also been developed. These tools can reduce the simulation time by a factor that is roughly proportional to the number of processors available and, therefore, facilitate the study of complex settings that may require unaffordable execution times in a sequential simulation.The computer codes presented in this thesis have been tested in realistic medical physics applications and compared with other Monte Carlo codes and experimental data. Therefore, these codes are ready to be publicly distributed as free and open software and applied to real-life problems.

Mythological figures play a number of roles in literature: they may, of course, appear in person as developed characters, but they may also contribute more indirectly, as part of the substratum from which rhetorical argument or literary characterisation are constructed, or as a background against which other literary strategies (for example, the rewriting of epic or the appropriation of Greek culture by the Romans) can be marked out. This thesis sets out to examine the way in which the figure of Penelope emerges from unknown origins, acquires portrayal in almost canonical form in Homer's Odyssey, and then takes part in the subsequent interplay of Homeric and other literary allusions throughout later Classical literature (with chapters focusing particularly on fifth-century Greek tragedy, Hellenistic poetry, and Augustan poetry). In particular, it focuses on the manner in which, despite the potential complexities of the character and the possible variants in her story, she became quintessentially a stereotypical figure. In addition to considering example where Penelope is evoked by name, a case is also made for the thesis that allusion, or intertextual reference, could also evoke Penelope for an ancient audience. A central point of discussion is what perception of Penelope would be called to mind by intertextual reference. The importance of approaching relationships between ancient texts in intertextual terms rather terms of strict "allusion" is thus demonstrated. The formation of the simplified picture is considered in the light of folk-tale motifs, rhetorical simplification of myth, and favoured story patterns. The appendices include a summary of the myth of Penelope with all attested variants, and a comprehensive list of explicit references to her in classical literature.

Thesis (Ph. D.)--Florida State University, 2005. / Advisor: S. E. Gontarski, Florida State University, College of Arts and Sciences, Dept. of English. Title and description from dissertation home page (viewed Jan. 24, 2006). Document formatted into pages; contains v, 159 pages. Includes bibliographical references.

Η διπλωματική μας εργασία έχει ως θέμα της «οι αντιλήψεις των παιδιών ηλικίας 11 ετών σχετικά με το περιεχόμενο ενός κλασικού παιδικού μυθιστορήματος της Πηνελόπης Δέλτα, του «Τρελαντώνη». Το θέμα της είναι πρωτότυπο καθώς από την βιβλιογραφική μας ανασκόπηση δεν εντοπίσαμε να έχει γίνει και να έχει δημοσιευτεί παρόμοια έρευνα στο παρελθόν. Ο λόγος που ασχοληθήκαμε με την μελέτη του εν λόγω θέματος ήταν το γεγονός ότι ο «Τρελαντώνης» είναι ένα παιδικό μυθιστόρημα ιδιαίτερα αγαπητό στα παιδιά του δημοτικού από το 1932 μέχρι σήμερα, παρόλο που η ιστορία που περιγράφει έχει πραγματοποιηθεί όταν η Πηνελόπη Δέλτα ήταν ακόμη παιδί, δηλαδή στα τέλη του 19ου αιώνα. Μελετώντας προσεκτικά όλα τα κεφάλαια του βιβλίου ξεχωρίσαμε ορισμένες έννοιες που θωρήσαμε ενδιαφέρουσες και θα επιθυμούσαμε να ανακαλύψουμε πώς τις αντιλαμβάνονται τα παιδιά σήμερα. Αυτές είναι η έννοια της ντροπής, του αξιωματικού, του βασιλιά και της ζητιανιάς που υπάρχουν μέσα στα αποσπάσματα-σκηνές του βιβλίου που διαλέξαμε να διαβάσουμε στα παιδιά στα πλαίσια μιας ηχογραφημένης συνέντευξης μαζί τους. Επομένως για την διερεύνηση του συγκεκριμένου θέματος πραγματοποιήσαμε συνέντευξη σε 41 αγόρια και κορίτσια ηλικίας 11 ετών από τον διευρυμένο σύμφωνα με τον Καλλικράτη, Δήμο Πατρέων. Προφανώς τα αποτελέσματα στα οποία καταλήξαμε μπορεί να μην οδηγούν σε γενικεύσεις αλλά έχουν ενδιαφέρον ως ενδείξεις. / -

Made available in DSpace on 2015-05-14T12:40:04Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 546651 bytes, checksum: c72cdf3c4a94d186c6d09337285d33e1 (MD5) Previous issue date: 2010-03-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The present work analyses the novel The Penelopiad: The Myth of Penelope and Odysseus (2005), by the Canadian author Margaret Atwood, translated into Portuguese as A Odisséia de Penélope (2005), a narrative characterized as a recreation of the homeric myth. This novel offers its reader an opportunity of coming back to Greece, now having Penelope as a protagonist and narrator, opening the possibilities of representing this figure of classical myhtology beyond Homer s representations. According to Homer s narrative, in tune with patriarchal understanding of gender relations, women, specially Greek women, should become mothers and remain inside the gineceu, what his Penelope did. However, in the reconstruction and rereading of this epic text presented by Atwood, Penelope invites us to look through the brumes of the past in order to listen to possibly different arrangements about the story of her life. It is in this context that our work intends to present and discuss Atwood s Penelope, recognizing other possibilities of retelling this classic text, deconstructing Homer s view at different points and aspects. Thus, by examining the brackets, the intersticial spaces of the homeric narrative, Atwood reconstructs the character and the myth, enabling her Penelope to speak about everything that was silenced in the homeric text, revealing her view, opinion and explanation about those events. / O presente trabalho analisa The Penelopiad: The Myth of Penelope and Odysseus (2005), da autora canadense Margaret Atwood, traduzida para a língua portuguesa, como A Odisséia de Penélope (2005), narrativa caracterizada como recriação do mito homérico. Tal romance proporciona ao leitor um retorno à Grécia antiga, agora com Penélope como protagonista e narradora, abrindo o leque de representações desta figura da mitologia clássica para além da criação de Homero. De acordo com a narrativa homérica, afinada com a construção de um masculino bastante fortalecido à época, a mulher, especialmente a grega, caberia a maternidade e o enclausuramento no gineceu, atividades cumpridas à risca por Penélope, o que reconhecemos na personagem homérica. Porém, na reconstrução e releitura da épica desenvolvida por Atwood, Penélope convida-nos a espiar por entre as névoas de seu passado para ouvirmos a orquestração das falas de toda a sua vida. É nesse contexto que este trabalho pretende apresentar a Penélope de Atwood, reconhecendo uma outra possibilidade criada por esta autora canadense de contar a história clássica, desconstruindo a versão apresentada por Homero em diversos momentos. Portanto, examinando, pois, as lacunas ou espaços intersticiais da narrativa homérica, Atwood reconstrói a personagem, ou o mito, concedendo a sua protagonista o direito de se pronunciar sobre o que no texto original passará em silêncio, revelando seu olhar, sua opinião e suas explicações sobre o desenrolar dos fatos.