The Heston model under stochastic interest rates

Tese de mestrado, Matemática Financeira, Faculdade de Ciências, Universidade de Lisboa,2008In this dissertation the Heston (1993) model is considered, but using, instead of a constant interest rate, stochastic interest rates according to Vasicek (1977) and to Cox, Ingersoll and Ross (1985) models. Under this framework, a closed-form solution is determined for the price of European standard calls, which, by using a manipulation implemented by Attari (2004), only require the evaluation of one characteristic function. For forward-start European calls, starting from the result for standard calls and using analytic characteristic functions, it is determined a closed-form solution that only requires one numerical integration. In the end, the results of these closedform solutions are compared with the results presented by Monte Carlo simulations for the considered models.Nesta dissertação é considerado o modelo de Heston (1993), mas em vez de utilizar uma taxa de juro constante, considera-se taxas de juro estocásticas segundo os modelos de Vasicek (1977) e de Cox, Ingersoll e Ross (1985). Neste contexto, é determinada uma solução fechada para a avaliação de standard calls Europeias, que, por ter sido usada uma manipulação implementada por Attari (2004), apenas necessitará da avaliação de uma função característica. Para calls forward-start Europeias, partindo do resultado apresentado para standard calls e utilizando funções característica analíticas, é determinada uma solução fechada que também recorrerá a apenas uma integração numérica. No final, os resultados destas fórmulas fechadas são comparados com os resultantes de simulações de Monte Carlo para os modelos considerados

Blogue: a literatura multifacetada e multimedial

Tese de mestrado em Estudos Comparatistas apresentada à Faculdade de Letras da Universidade de Lisboa, 2008Dentro da plataforma da internet, o blogue tem vindo a crescer como um novo medium nos últimos quinze anos. Apesar de, inicialmente, não ser considerado um medium literário, a popularidade adquirida em anos recentes, juntamente com a crescente produção com origem no consumidor, tornou o blogue num dos media mais criativos de sempre. Partindo da Teoria dos Polissistemas proposta por Itamar Even- Zohar, e tendo por corpus de análise o material de um ano do blogue Baghdad Burning, equacionamos nesta dissertação a possibilidade de o blogue ser um (novo) medium literário. Para tal, colocamos o conceito de literatura no quadro de uma dialéctica, que julgamos também subjacente à construção do cânone, entre o desejo de reconhecimento do produtor e a validação comunitária necessária. Os media existem em relação uns com os outros num universo polissistémico. Os media são incapazes de ter significado cultural sem outros media, uma vez que o espaço em que operam nunca é um espaço puro. O modo como os media melhoram e representam outros media é chamado remediação. Nesta dissertação exploramos o modo como o blogue remedeia o livro, bem como o modo como o livro remedeia o blogue, na convicção de que a remediação funciona em ambos os sentidos, e por isso o medium sucessor remedeia e é remediado pelo medium precursor.For the past fifteen years, the blog has been growing as a new medium within the internet. Although it was not regarded as a literary medium in the beginning, the popularity it achieved in recent years, along with the overwhelming user-generated content, made it one of the most creative media of all times. Having Itamar Even- Zohar's Polysystem Theory as our starting point, and taking one year of the blog Baghdad Burning as our corpus, we consider the possibility of the blog being a (new) literary medium. We see the concept of literature in a dialectical relation, and in terms that can also be applied to the construction of the canon, between the desire of recognition of the producer and the validation of the community. Media exist in relation with each other in a polysystemic universe. Media are unable to find their cultural significance without other media, for there is not an ideal pure space in which they operate. The way media improve and depict other media is called remediation. In this dissertation we explore the way the blog remediates the book and the book remediates the blog, for remediation works both ways, and therefore the successor media remediates and is remediated by its predecessor

The importance of creative collectives in music industry: the Leiria's microclimatic music scene case

The present dissertation has for subject "The importance of creative clusters in Music Industry", but also takes in consideration the Microclimatic music scene case of Leiria, a city in the centre of Portugal. Music always have defined and influenced societies. Nowadays, it still plays a major role in modern society, but also has a profound and meaningful position in the world’s economy. Following this idea, it is purposed to consider the definition and context of Music Industry, to better understand how it influences the all market behind and how it interacts with companies and organizations that can be related to music. It was of interest to understand how Music scenes arise in certain geographic areas, once they have been one of the steps to have a greater understanding of the importance of clustering geographically, and its influences in the development of regional economic growth, where some scenarios were taken in account. The following chapter refers to creative industries and creative clusters, where it is searched the importance of creative industries to cluster and its influences in communities around. The last chapter takes in account the music scene in Leiria, how it aroused and the influences on the community. Finally, it was conducted a survey for music bands/music artists, creatives, producers, agents and promoters, to understand, what are, in fact, the importance's of creative collectives in producing and collaborating with music bands/music artists on their works.A presente dissertação tem como título "A importância das aglomerações de criativos na Indústria da Música", mas considera, também, o caso do Microclima do cenário musical de Leiria, uma cidade no centro de Portugal. A música sempre definiu e influenciou sociedades. Nos dias de hoje, ainda tem um papel bastante importante na Sociedade moderna, mas tem, também, uma profunda e significante posição na economia mundial. Através desta ideia, é proposto a consideração da definição e contexto da Indústria da Música, para melhor perceber como influencia todo o mercado envolvente, e como interage com empresas e organizações que podem estar relacionadas com música. Revelou ser de interesse, perceber de que forma crescem alguns cenários musicais, em certas áreas geográficas, uma vez que estes foram dos principais passos para ter uma maior compreensão da importância de aglomerações geográficas, assim como das suas influências no desenvolvimento do crescimento económico regional. Alguns cenários, são tidos em consideração. O seguinte capítulo refere-se às Indústrias criativas e às aglomerações criativas, onde se procura perceber a importância de aglomerações entre Indústrias criativas, assim como das suas influências nas comunidades adjacentes. Por último, é conduzido um questionário para bandas musicais/artistas musicais, criativos, produtores, agentes e promotores, para melhor perceber, qual é de fato, a importância dos coletivos de criativos na produção e colaboração em trabalhos para bandas musicais/artistas musicais

Study and Characterization of Composite Materials: Biomedical Applications

In the scope of the Master’s Degree in Mechanical Engineering - Industrial Production, it was sought to study the impact of sustainable materials in biomedical applications, with special focus on composite materials. When gathering information to perform the state of the art of this work, regarding composite materials and some of their biomedical applications, it was found that there was not much evidence regarding the customized production of transfemoral prostheses using both sustainable materials and home-available low-cost manufacturing technologies. To contribute exploring the identified research gap, numerical models were developed to carry out simulations based on finite element analysis. In turn, these have made it possible to evaluate not only the effect of friction, but also the effect that the materials and their constitutive laws have on the stress field developed in the biomechanical system, which directly affects the comfort and health of patients. Additionally, the simulations also made it possible to analyze various materials to verify their suitability for the application in question. The results obtained made it possible to highlight sustainable materials with the potential to be used to produce sockets for transfemoral prostheses and, in turn, to demonstrate the possible suitability for customized production of these medical devices directly by patients in their homes, using low-cost additive technologies that can be easily available at home

Causal characterization of functional connectivity through the spread of electrically induced oscillations in the epileptic human brain

Little is known about the rules governing the spread of local entrainment within synchronized networks distributed across the brain. The assessment of the causal influences impacting information flow between two brain regions have mainly relied on confirmatory model-driven approaches (such as dynamic causal modeling and structural equation modeling) and exploratory data driven approaches (such as Granger Causality analysis). However, stimulation-driven approaches offer a unique opportunity to impact ongoing brain activity and describe the causal consequences of such manipulations, performed on a specific node of a complex cerebral network. In this project, we characterize causal functional interactions between brain regions by assessing how frequency-tuned electrical currents delivered intracranially in awaken epileptic patients enhance inter-regional synchrony between pairs of areas. To achieve this goal, we worked with an existing iEEG database from 18 medication-resistant epilepsy patients undergoing Intracortical Stimulation Mapping Procedures (ISMP) performed to causally identify and localize the epileptogenic foci, prior to neurosurgical removal. Patients are implanted with series of multi-electrodes in well-known brain regions under MRI guidance. Intracranial EEG contacts allow continuous recordings and the delivery through pairs of adjacent contacts of biphasic pulses of rhythmic Direct Electric Stimulations (DES) at a 50Hz frequency coupled to electrophysiological recordings. Measuring significant increases in gamma power ( 50Hz) observed during the stimulation period (vs. prior the stimulation), and significant increases of Phase-Locking Value (PLV) between signals recorded in the electrically stimulated regions and activity evoked in the rest of implanted regions during stimulation (vs. prior simulation), we characterize the spread of oscillatory entrainment from the stimulated region to the remaining regions, thus establishing a network of functional connectivity in the brain. By comparing this network with the one shown during resting-state, we assess how entrainment to frequency-tuned electrical currents delivered intracranially is predicted by the resting-state functional connectivity network

Histologia e fisiologia da dor de origem pulpar

Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Medicina DentáriaNa prática clínica dentária é comum observar que um grande número de pacientes que solicitam uma consulta sem agendamento se deve a uma urgência ou emergência. Normalmente, esses pacientes chegam de maneira inesperada e com dores severas, alterando a rotina da agenda do dentista e, simultaneamente, criando situações de tensão que afetam todo o pessoal que trabalha no consultório. Numa situação de urgência endodôntica o paciente apresenta dor, edema, ou ambos em vários graus de gravidade, como resultado de um problema pulpar ou periapical, pelo que a solução recai no endodontista. Daí a importância do Médico Dentista em realizar um correto diagnóstico pulpar e perirradicular, conhecer as alterações fisiológicas que advêm da dor pulpar e analisar histologicamente as alterações pulpares. No presente trabalho pretende-se, através de uma revisão bibliográfica, aprofundar o conhecimento sobre a dor em endodontia, o diagnóstico das várias patologias pulpares e perirradiculares e a sua fisiologia e histologia. In dental clinical practice it is common to observe that a large number of patients who request an appointment without consultation are due to urgency or emergency. Typically, these patients arrive unexpectedly and with severe pain by changing the routine dentist agenda and, simultaneously, creating stressful situations that affect all staff working in the office. In an endodontic emergency situation the patient presents pain, edema, or both in various degrees of severity, as a result of pulp and periapical problem, so that the solution falls within the endodontist. Hence the importance of Dentist in making a correct diagnosis pulp and periradicular, meet the physiological changes that come from pulp pain and analyze histologically the pulp changes. In this work it is intended, through a literature review, to deepen knowledge about pain in endodontics, diagnosis of various pulp and periradicular diseases and their physiology and histology