We consider the N-body problem given by quasihomogeneous force functions of the form (C_1)/r^a + (C_2)/r^b (C_1, C_2, a, b constants and a, b positive with a less than or equal to b) and address the fundamentals of homographic solutions. Generalizing techniques of the classical N-body problem, we prove necessary and sufficient conditions for a homographic solution to be either homothetic, or relative equilibrium. We further prove an analogue of the Lagrange-Pizzetti theorem based on our techniques. We also study the central configurations for quasihomogeneous force functions and settle the classification and properties of simultaneous and extraneous central configurations. In the last part of the thesis, we combine these findings with the Lagrange-Pizzetti theorem to show the link between homographic solutions and central configurations, to prove the existence of homographic solutions and to give algorithms for their construction. / Graduate

This thesis presents a new power circuit configuration to be used in shunt active power filters. A new control algorithm based on the linear voltage control suitable for the proposed circuit is introduced. The system is analysed both in time and frequency domains. The practical implementation of the system proves its suitability for the proposed task. The switching frequency of the proposed circuit is much lower than that in other active filters. The switching losses are then considerably reduced, in addition to the fact that the switching devices can withstand larger values of currents being switched on and off at lower frequencies which is an advantage to this circuit. The component sizes (capacitors and inductors) in the proposed circuit are also much smaller than those in other filter configurations. In addition, the thesis presents a new method for categorising the active filter systems proposed in the surveyed literature. The survey includes a comparison of these techniques showing their respective merits and drawbacks. The thesis also includes an implementation of a reference current generator that is suitable for single-phase applications without the need for excessive computations. The technique involves a modified Fourier analysis, which is suitable for active filtering applications.

One dimensional, linear, plane-wave modelling of silencer systems in the frequency domain provides an efficient means to analyse their acoustic performance. Software packages are available to analyse silencers within these modelling parameters; however, they are heavily restricted. The thesis develops an algorithm that increases the computational efficiency of the silencer analysis. The thesis concentrates on how data, within a software package, is stored, retrieved and analysed. The computational efficiency is increased as a result of the predictable patterns caused by the repetitive nature of exhaust system analysis. The work uses the knowledge gained from the construction of two previous algorithms of similar parameters; it isolates and maximises their advantages whilst minimising their associated disadvantages. The new algorithm is dependent on identifying consecutively sequenced exhaust components and sub-systems of such components within the whole exhaust system. The algorithm is further generalised to include multiple time-variant sources, multiple radiation points and exhaust systems that have a balance pipe. Another feature of the improved algorithm encompasses the option of modelling secondary noise sources such as might arise from flow generated noise or be included for active noise cancellation systems. The validation of these algorithmic techniques is demonstrated by comparison of the theoretical noise predictions with experimental or known results. These predictions are achieved by writing computational code using object orientated programming techniques in the language of c++ to implement the algorithms.

This dissertation reports on the results of a study into the characteristics of epistemic topoi and the methods of their identification in a corpus of biomedical publications. The study was conceived in response to the need for a systematized description of the organization of argumentative text and discourse. This need is well recognized in knowledge-intensive fields: information processing, storage, and retrieval; corpus analysis and natural language processing; data mining, knowledge management and translation; professional training and education. The study followed the design of a situated study combined with a methodological inquiry. I used inductive methods to describe the features and functions of recurrent patterns of argumentative and linguistic organization. This part of the study consisted in close reading of a corpus of fifty-five NTG papers and rhetorical and linguistic annotation of seventeen clinical studies (45,599 words) selected from the corpus. The data was generated by means of rhetorical and linguistic analysis. Visual annotation played an essential role in the identification and description of the argumentative patterns, complementing the traditional methods of corpus analysis. Forty-eight basic and nine composite epistemic topoi forming the superstructure of the papers were identified in the corpus. The topoi were found to be loosely associated with the IMRD structure and signalled with configurations of lexicogrammatical, semantic, deictic, and coreferential features. The topoi were classified according to the modes of reasoning and textual and discursive functions. The obtained results confirmed earlier insights into the links of linguistic patterning with text and discourse semantics. A significant outcome of the linguistic analysis is a catalogue of linguistic features that were found to have regular links with the topoi in the corpus. The role of linguistic configurations as identifiers of argumentative meanings makes them a valuable medium of text and discourse analysis. By linking the argumentative meanings to the surface features of text and discourse, the analysis of linguistic configurations presents informatics practitioners with an alternative to the current methods of natural language processing and knowledge management. The catalogue of linguistic features and a detailed description of the study design make the presented findings amenable to secondary analysis, extrapolation, and generalization. The auxiliary objectives of this study were a survey of argumentative practices represented in the corpus and a review of the state of epistemic research. The results of the survey and review suggest that agonistic reasoning practices and over-reliance on reductionist models have negative implications for research writing and communication. Specifically, they hamper analysis of argumentative organization of natural text and discourse. As an alternative to agonistic argumentation, I propose an argumentation model based on Aristotle’s and Kneale’s conceptions of situated knowledge and learning. The model of textual and discursive organization that accommodates situated knowledge and learning is political stasis. This model can be used as a heuristic and analytic tool. In this dissertation I use it as an explanatory conception and as a system of reference points for identifying significant research trends both in argumentation studies and in clinical NTG research.

Thesis (Ph. D.)--University of Sydney, 2009. / Title from title screen (viewed May 1, 2009) Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy Economics to the Faculty of Economics and Business, University of Sydney. Degree awarded 2009; thesis submitted 2008. Bibliography: leaves 93-97. Also available in print form.

Thesis (Ph.D.)--Case Western Reserve University, 2009 / Department of Information Systems Weatherhead School of Management Includes abstract Includes bibliographical references Available online via the OhioLINK ETD Center

abstract: Web applications continue to remain as the most popular method of interaction for businesses over the Internet. With it's simplicity of use and management, they often function as the "front door" for many companies. As such, they are a critical component of the security ecosystem as vulnerabilities present in these systems could potentially allow malicious users access to sensitive business and personal data. The inherent nature of web applications enables anyone to access them anytime and anywhere, this includes any malicious actors looking to exploit vulnerabilities present in the web application. In addition, the static configurations of these web applications enables attackers the opportunity to perform reconnaissance at their leisure, increasing their success rate by allowing them time to discover information on the system. On the other hand, defenders are often at a disadvantage as they do not have the same temporal opportunity that attackers possess in order to perform counter-reconnaissance. Lastly, the unchanging nature of web applications results in undiscovered vulnerabilities to remain open for exploitation, requiring developers to adopt a reactive approach that is often delayed or to anticipate and prepare for all possible attacks which is often cost-prohibitive. Moving Target Defense (MTD) seeks to remove the attackers' advantage by reducing the information asymmetry between the attacker and defender. This research explores the concept of MTD and the various methods of applying MTD to secure Web Applications. In particular, MTD concepts are applied to web applications by implementing an automated application diversifier that aims to mitigate specific classes of web application vulnerabilities and exploits. Evaluation is done using two open source web applications to determine the effectiveness of the MTD implementation. Though developed for the chosen applications, the automation process can be customized to fit a variety of applications. / Dissertation/Thesis / Masters Thesis Computer Science 2018

Made available in DSpace on 2015-05-14T12:39:53Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 1784464 bytes, checksum: e18212f0d4ab6b2535791fde07cb75a8 (MD5) Previous issue date: 2014-05-22 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / This study called The lyrical depictions of death in H. Dobal´s poetry is dedicated to investigating expressive stylistic settings of death in the poetry of Hindemburgo Dobal Teixeira, whose poetry was observed as being deeply imbibed of the constructs of this issue of essence, which is very significant and crucial for humanity. From the assumption that it is possible to recognize a variety of ways and biases of settings of death in the poetry of H. Dobal, this study paper proposes the recognition and categorization of these poetic constructs, in order to contribute more specifically, to the critic density of this author from Piauí, and more generally, for studies of Brazilian poetry, especially with regard to the issue of death. The analytical course was undertaken in the light of studies of the critic and historian Antonio Candido in his writing focused on the themes of Brazilian literature as cultural production, which is dialectically gestated within society and carried out by agents in their relationships and contexts, transmuted into literary art, in this particular case, the poetry of H. Dobal. From the same social context as Antonio Candido, in questions of theoretical nature on literature and society, other prominent thinkers in the international sphere contributed who add to this understanding, such as Walter Benjamin and Theodor Adorno. To provide groundings to the studies pertaining to the subject of death, the study of several researchers have been associated, mainly from French Philippe Ariès and Edgar Morin, and Brazilian, Joao José Reis and Júlio José Chiavenato. As for the concepts and methods chosen for theme exploration with focus on the poetic lines, with respect to the instrumental analysis and views on the lyrical element, in addition to Antonio Candido himself, the analytic process was guided by scholars in this area of the literature, such as Emil Staiger, Mikel Dufrenne, T.S. Eliot, Paul Valery and Otávio Paz, among others. With the look always towards tracing the literary constructions of "Death", the study dived into in the exercise of scanning poetic figures in a careful analytical course, in order to bring to light what was observed as a cast of figurations of the Death issue, which reveal themselves as genuine contributions of this poet from Piauí to the literary panorama of Brazilian poetry, in the recognition , evaluation and dissemination of which this study pursues. Finally, from the findings gathered, we define a set of settings of categories of death, taken out from Dobal´s poetics, which are presented as a contribution to studies on the theme of death in the world of poetry. / O presente estudo denominado As representações líricas da morte na poesia de H. Dobal se dedica à investigação das configurações estilísticas expressivas da morte na poesia de Hindemburgo Dobal Teixeira, cuja obra poética observou-se profundamente embebida dos constructos dessa temática de essência tão significativa e crucial para a humanidade. A partir da hipótese de que é possível reconhecer uma variedade de caminhos e de vieses das configurações da morte na poesia de H. Dobal, o trabalho propõe o reconhecimento e a categorização desses constructos poéticos, no intuito de contribuir, de forma mais específica, para a fortuna crítica do autor piauiense, e, de maneira mais geral, para os estudos da poesia brasileira, sobretudo no que diz respeito ao tema da morte. O percurso analítico foi empreendido à luz dos estudos do crítico e historiador Antonio Candido em sua escrita voltada para as temáticas da literatura brasileira como produção cultural dialeticamente gestada no âmago da sociedade e protagonizada por seus atores em suas relações e contextos, transmutados em arte literária, neste caso específico, a poesia de H. Dobal. Da mesma vertente social de Antonio Candido, nas questões de natureza teórica sobre literatura e sociedade, contribuíram outros pensadores de destaque na esfera internacional que se aliam nessa compreensão, tais como Walter Benjamin, Georg Lukács e Theodor Adorno. Para calçar os estudos nas questões atinentes ao tema da morte, associam-se os estudos de vários pesquisadores, principalmente dos franceses Phillippe Ariès e Edgard Morin, e dos brasileiros, João José Reis e Julio José Chiavenato. Quanto aos conceitos e métodos escolhidos para as explorações do tema em foco nas linhas poéticas, no que diz respeito ao instrumental de análise e concepções sobre a lírica, além do próprio Antonio Candido, o processo analítico foi guiado por estudiosos desta área da literatura, tais como Emil Staiger, Mikel Dufrenne, T.S. Eliot, Paul Valery e Otávio Paz, dentre outros. Com o olhar sempre voltado para o rastreamento das construções literárias sobre a Morte , mergulhou-se no exercício de garimpar figuras poéticas em um percurso analítico atento, a fim de trazer à tona o que se observou como sendo um elenco de figurações do tema da Morte, que se revelam como contribuições genuínas do poeta piauiense ao panorama literário da poesia brasileira, em cujo reconhecimento, avaliação e divulgação este trabalho se empenha. Ao final, a partir dos achados reunidos, define-se um conjunto de categorias de configurações da morte, desentranhadas da poética de Dobal, as quais se apresentam como contribuição aos estudos sobre a temática da morte no universo da poesia.

Este trabalho propõe uma nova estrutura cinemática paralela tridimensional com três graus de mobilidade que pode ser aplicada como robô manipulador. O volume do espaço de trabalho disponível é empregado como índice para avaliar o desempenho cinemático do mecanismo. As cinemáticas de posição e velocidade são desenvolvidas, tendo em vista o levantamento das configurações singulares e do espaço de trabalho. Os resultados obtidos com as cinemáticas direta e inversa são comparados de modo a verificar a correspondência entre eles. São levantadas diversas configurações singulares que correspondem ao alinhamento entre as barras das cadeias ativas do mecanismo e uma família de singularidades para uma das cadeias ativas é apresentada. O volume do espaço de trabalho do mecanismo é calculado pelo método da discretização, de modo a avaliar o volume do espaço de trabalho disponível, bem como a identificação da influência dos parâmetros dimensionais do mecanismo sobre este volume. O volume do espaço de trabalho com os parâmetros ótimos é expressivo, quando comparado com aqueles alcançados por manipuladores robóticos convencionais. / This dissertation proposes a novel three-degree-of-freedom parallel kinematic structure in order to be applied as a three-dimensional robot manipulator. The volume of the available workspace is employed as a performance index to evaluate the kinematic behavior of the mechanism. The position and velocity kinematics are developed for mapping singular configurations and evaluating the workspace. The results obtained by performing the direct and inverse kinematics are compared in order to verify the consistency between them. It is demonstrated that most of singular configurations is represented by the alignment of the links that belong to each active chain. In addition, a family of singularities for one of the active chains is presented. The volume of the workspace is calculated by using the discretization method not only for evaluating the feasible workspace but also for identifying the influence of dimensional parameters with respect to this volume. The achieved workspace by employing the optimal parameters is comparable to that reached by conventional robot manipulators.

No presente trabalho apresentamos algumas soluçõesoes clássicas para o problema de dois e três corpos. Uma solução memorável para o problema de três corpos, na qual os corpos perfazem uma coreografia em forma de Oito, esta soluçãoo foi encontrada em 2000 por Montgomery e Chenciner. Por fim abordamos um pouco do problema clássico de n-Corpos e suas soluções particulares. / In this work we present some classical solutions for the Newtonian problem with two and three bodies. A remarkable solution for the three body problem, found by Montgomery and Chenciner, in which each body has an eight-shaped orbit is presented. Finally some particular solutions of the n-body problem and the so called central configurations, are presented and discussed.