Thesis (M.S.)--University of Wisconsin, 1962. / Extension Repository Collection. Typescript (carbon copy). eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 87-88).

Thesis (Ph. D.)--University of Wisconsin, 1964. / Extension Repository Collection. Typescript (carbon copy). Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 173-178).

[pt] O uso de códigos corretores de erro tem sido a alternativa convencional utilizada em sistemas de comunicação digitais para melhorar o desempenho em termos de probabilidade de erro de bit dos sistemas com limitação de potência. A melhoria do desempenho quando se emprega estes códigos convencionais é alcançada com um aumento na faixa de freqüências utilizada pelo sistema ou uma redução na taxa de transmissão de informação. Técnicas que realizam a modulação e a codificação de forma integradas permitem obter desempenho superior ao de sistemas sem codificação, sem acarretar aumento de faixa. O presente trabalho analisa, através de simulação em computador digital, o desempenho de sistemas de comunicações digitais que empregam a modulação Multi-h, uma modulação codificada que faz uso eficiente da faixa. A simulação realizada considera um ambiente com não- linearidade, limitação de faixa e perturbação por um ruído aditivo branco Gaussiano. A técnica de simulação emprega utiliza o sinal em banda básica representado por suas amostras tomadas no domínio do tempo a intervalos constantes. As filtragens necessárias para simular o efeito da limitação de faixa foram realizadas com filtros de Butterworth digitais. O desempenho de códigos com número pequeno de estados ( = < 16) e probabilidade de erros maiores do que 10-4 foi analisado. Um programa para cálculo de distância Euclideana mínima normalizada, d min, de códigos Multi-h foi desenvolvido. A distância d min, é utilizada para estabelecer um limitante da probabilidade de erro por bit em sistemas cuja única perturbação é o ruído aditivo branco Gaussiano. Códigos com d min maiores possuem melhor desempenho e portanto este parâmetro é utilizado para escolher bons códigos. Um programa para cálculo da densidade espectral de potência de códigos Multi-h foi também desenvolvido. Para reduzir a complexidade do decodificador o número de estados da treliça correspondente ao código utilizado deve ser pequeno. Escolhendo-se um conjunto adequado de índices obtem-se códigos de complexidade reduzida com bom desempenho e boas características espectrais. Uma das restrições impostas ao conjunto de índices para reduzir a complexidade do decodificador é que os mesmos sejam razões nk/q entre números inteiros. Outros aspectos relacionados à redução da complexidade são discutidos neste trabalho. Em particular, uma propriedade que o conjunto de índices de modulação deve obedecer para que o número de estados da treliça seja q é estabelecida. Uma discussão sobre características da estrutura da treliça é também apresentada. / [en] Error correcting codes have been used in power limited digital communication systems to improve the system error probability performance. This performance improvement is obtained at the price of an expanded occupied bandwidth or a lower rate of information transmission. Integrated coding and modulation techniques allow an increased performance without this bandwitdt expansion. In this thesis, a digital computer simulation analysis of the performance of communication systems which incorporates Multi-h codes, a bandwidth efficient modulation, is carried out. The simulated system consider a band-limited non-linear channel perturbed by additive, white Gaussian noise. The simulation technique selected uses a base-band signal represented by it´s time domain samples equally spaced. The band limiting effect is obtained with Butterworth digital filters. The performance of codes with small number of states ( = < 16) and error probability range greater than 10 exp(-4) is analised. A computer program to calculate the normalized mínimum Euclidean distance, d min, of Multi-h codes was developped. The distance d min is used to establish an upper bound on the bit error probability for transmission over additive, white Gaussian noise channels. Codes with larger dmin have a better performance, been dmin, thus, an indication of good codes. A program developped to calculate power spectrum density of Multi-h codes is also presented. To reduce decoder complexity the number of trellis states should be small. By properly selecting a set of modulation indices codes with good performance, reduced complexity and small spectral occupation is obtained. A restriction on the set of indices to get a reduce complexity decoder is to have indices d which are integer ratios nk/q. Other related aspects are discussed in this work. In particular, a condition to get a number of trellis state equal to q is proposed. A discussion on the structed of the trellis is also presented.

Orientador: Alberto Luiz Serpa / Dissertação (mestrado - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-20T02:35:52Z (GMT). No. of bitstreams: 1 Tapias_RenanMoro_M.pdf: 4789122 bytes, checksum: 0c921b95857d6987a5596ae935a85719 (MD5) Previous issue date: 2012 / Resumo: Esta dissertação aborda técnicas de controle robusto H-infinito para sistemas dinâmicos lineares com incertezas paramétricas. Para obtenção do modelo da estrutura em estudo, utiliza-se o método de elementos finitos. A partir do modelo da estrutura, consideram-se incertezas paramétricas, sendo elas, na frequência natural e no fator de amortecimento. As incertezas paramétricas quando consideradas para projeto do controlador H-infinito são tratadas pela abordagem poli tópica. Essa metodologia utiliza o conceito de Desigualdades Matriciais Lineares (LMI). Ainda na fase de projeto do controlador, filtros de ponderação são utilizados para impor uma certa forma em frequência. As incertezas dos sistemas em estudo são consideradas como sendo tanto variantes como invariantes no tempo. O controlador encontrado por essa metodologia se mostrou robusto a incertezas paramétricas, garantindo estabilidade e boa atenuação de vibração dos modos considerados em projeto / Abstract: The aim of this dissertation is to study the H-infinity robust control techniques for linear dynamic systems with parametric uncertainties. The finite element method was employed to find the model of the flexible structure. When dealing with the model, parametric uncertainties were considered for natural frequencies and for damping of the structure. The parametric uncertainties for the H-infinity controller design are handled in the polytopic approach. This methodology uses the concept of Linear Matrix Inequalities (LMI) for the controller project. Weighting filters were used to impose desired frequency response in the controller design. Systems with uncertainties were considered variant and invariant in time. The controller found using this methodology was robust to parametric uncertainties, ensuring stability and good attenuation of vibration in design the considered modes / Mestrado / Mecanica dos Sólidos e Projeto Mecanico / Mestre em Engenharia Mecânica

Let G and H be graphs. We say G is H-critical, if every proper subgraph of G except G itself is homomorphic to H. This generalizes the widely known concept of k-color-critical graphs, as they are the case H = Kk - 1. In 1963 [T. Gallai, Kritiche Graphen, I., Magyar Tud. Akad. Mat. Kutató Int. Közl. 8 (1963), 373-395], Gallai proved that the vertices of degree k in a Kk-critical graph induce a subgraph whose blocks are either odd cycles or complete graphs. We generalize Gallai's Theorem for every H-critical graph, where H = Kk - 2 + H′, (the join of a complete graph Kk - 2 with any graph H′). This answers one of the two unknown cases of a problem given in [J. Nešetřil, Y. Nigussie, Finite dualities and map-critical graphs on a fixed surface. (Submitted to Journal of Combin. Theory, Series B)]. We also propose an open question, which may be a characterization of all graphs for which Gallai's Theorem holds.

This critical analysis focuses on my investigations over the past almost 24 years into what I term the ‘Satanic ritual abuse myth’ – or ‘Satanic panic’ – the controversy over recovered versus false memories, and, more recently, the validity of the diagnosis of multiple personality disorder (MPD), now known as dissociative identity disorder (DID). This reflective analysis, written for the PhD by prior publication, explores how my journalism has made an original and significant contribution to knowledge in my own field, investigative journalism, and how it relates to – and has contributed to - the literature in several academic disciplines – the psychology of false memories, the anomalistic psychology of weird beliefs, and the sociology of moral panics. I was one of the first researchers internationally to conclude there was no physical, forensic evidence that Satanic abuse existed. My ‘Making of a Satanic Myth’ feature, published in the Independent on Sunday in 1990, has been cited in the literature, along with key investigations since. I describe the methodology and conduct of research during my continuing investigations into the origins and spread of the ‘Satanic panic’ and related controversies of false memories and multiple personalities. The dissertation itself adds significantly to academic theories and historical accounts of these events from the 1980s until today. Through a wide reading of the literature I have pieced together a forensic chronology which provides a unique overview of a particular era of striking and peculiar phenomena. On reflection, I conclude that my investigations provide evidence for the concept of moral panics created through an ‘explosive amplification’ of anecdote, social and official concern about issues such as child abuse, spread by ‘claims-makers’ and a globalised mass media. Although sporadic claims of Satanic abuse continue I conclude there is still no corroborating evidence.

No description available.

This thesis investigates the origin and development of EC cultural policy through four case studies of policy formation. The four cases selected occurred in the pre-Maastricht period, 1955-1988. The first two policy experiences correspond to a pre-history of the EC´s cultural policy, the latter two resulted in authoritative policy decisions by EC institutions. The research objectives include historical understanding of this policy experience and an examination of the process of European policy formation. It draws upon archive material from the Historical Archives of the European Union. This material is organised and analytically narrated around the events that make up each episode. The approach is theoretically oriented case research – each experience studied corresponds to a policy episode. These policy episodes are analysed through a combined theoretical framework based on Kingdon´s multiple streams model (1995), which explains the pre-decisional and decision-making stages of the policy-making process, and on institutional processualism which seeks to attain a causal understanding of these processes that is sensitive to institutional context. This thesis represents one of the first applications of this model in the field of cultural policy. The comparative approach deployed identifies similarities and differences among the four episodes studied and compares the dynamics of the policy process between them with a view to generating theoretical generalisations about the formation of cultural policy in the EC in the period of interest. The application of Kingdon’s model to European public-policy to an extent tested the model, though ultimately it demonstrates its flexibility and relevance to a variety of agenda situations and analysis. The model was less successful in explaining policy formulation, in this instance, which is explained by the pervading institutional reach of the EC Treaties. A specific interest of Kingdon´s is policy entrepreneurship and how it affects the policy process and this is also a main interest of this research. The model worked well here but proved limited in that it generated only a partial explanation for the agency of cultural policy entrepreneurs whose motivations, we found, are intrinsic and specific to cultural policy.

The objective of the thesis is to use econometric analysis to assess the impact of power sector reforms in Africa during the period 1988-2005, using panel data analysis. The study uses fixed effects model, where all the reform variables are assumed to be strictly exogenous, but goes a step further, to endogenise the variables using 1-step Generalized Method of Moments (GMM) estimation. To ensure the robustness of the results, the study makes use of both static and dynamic models and other econometric methods to reduce as far as practicable, the likelihood of spurious correlation. The main conclusion from the generation sector study is that, the establishment of a regulatory agency is generally associated with favourable generation outcomes. These are likely to be achieved after a minimum period of 2 years for installed plant capacity, 3 years for plant energy output, and 7 years for plant utilization. Passage of energy sector law seems likely to enhance both installed generation capacity and actual plant energy output. On the impact of private sector participation (PSP) in the generation sector, management and lease contracts, as well as greenfield projects seem likely to enhance installed capacity and actual plant output. On plant utilization, the favourable outcome is associated with concessions and greenfield projects. For the network sector, the result seems to indicate that the co-existence of energy sector law and regulatory agency can reduce transmission network loss levels. The result on the distribution system however show that though energy sector law and regulation are necessary, they are not likely to be sufficient to reduce the system loss level. Effective loss reduction in the distribution sector is likely to be achieved if management and lease contract is present as a PSP option. The long lags associated with the existence of regulation, underline the notion that institutional changes alone are unlikely to be sufficient, if the workforce is not competent and well trained. This implies that regulatory agencies in Africa are still fragile, and it will take quite sometime to build the capacity of key professional staff to operate whatever institutional and regulatory frameworks are chosen.

No description available.