This thesis is concerned with the development of a novel discrete particle swarm optimization (PSO) technique and its application to the discrete optimization of digital filter frequency response characteristics on the one hand, and the high-level synthesis of bit-parallel digital filter data-paths on the other. Two different techniques are presented for the optimization of sharp-transition band frequency response masking (FRM) digital filters, one of which is based on the conventional finite impulse-response (FIR) digital subfilters, and a new hardware-efficient approach which is based on utilizing infinite impulse-response (IIR) digital subfilters. It is shown that further hardware efficiency can be achieved by realizing the IIR interpolation subfilters by using the bilinear-LDI approach. The corresponding discrete PSO is carried out over the canonical signed digit (CSD) multiplier coefficient space for direct mapping to digital hardware considering simultaneous magnitude and group-delay frequency response characteristics. A powerful encoding scheme is developed for the high-level synthesis of digital filters based on discrete PSO, which preserves the data dependency relationships in the digital filter data-paths. In addition, a constrained discrete PSO is developed to overcome the limitations which would manifest themselves if the conventional PSO were to be used. Several examples are presented to demonstrate the application of discrete PSO to the design, high-level synthesis and optimization of digital filters. / Communications

Doctor of Philosophy / Collective actions of large animal groups result in elaborate behaviour, whose nature can be breathtaking in their complexity. Social organisation is the key to the origin of this behaviour and the mechanisms by which this organisation occurs are of particular interest. In this thesis, these mechanisms of social interactions and their consequences for group-level behaviour are explored. Social interactions amongst individuals are based on simple rules of attraction, alignment and orientation amongst neighbouring individuals. As part of this study, we will be interested in data that takes the form of a set of directions in space. In Chapter 2, we discuss relevant statistical measure and theory which will allow us to analyse directional data. These statistical tools will be employed on the results of the simulations of the mathematical models formulated in the course of the thesis. The first mathematical model for collective group behaviour is a Lagrangian self-organising model, which is formulated in Chapter 3. This model is based on basic social interactions between group members. Resulting collective behaviours and other related issues are examined during this chapter. Once we have an understanding of the model in Chapter 3, we use this model in Chapter 4 to investigate the idea of guidance of large groups by a select number of individuals. These individuals are privy to information regarding the location of a specific goal. This is used to explore a mechanism proposed for honeybee (Apis mellifera) swarm migrations. The spherical theory introduced in Chapter 2 will prove to be particularly useful in analysing the results of the modelling. In Chapter 5, we introduce a second mathematical model for aggregative behaviour. The model uses ideas from electromagnetic forces and particle physics, reinterpreting them in the context of social forces. While attraction and repulsion terms have been included in similar models in past literature, we introduce an orientation force to our model and show the requirement of a dissipative force to prevent individuals from escaping from the confines of the group.

Thesis (M.S.)--Rochester Institute of Technology, 2008. / Typescript. Includes bibliographical references (leaves 71-73).

Thesis (M.Eng.(Industrial Engineering))--University of Pretoria, 2008. / Includes bibliographical references.

Thesis (M.S.)--Rochester Institute of Technology, 2009. / Typescript. Includes bibliographical references (leaves 91-97).

Thesis (M. Sc.)(Computer Science)--University of Pretoria, 2006. / Includes summary. Includes bibliographical references. Available on the Internet via the World Wide Web.

The Coalition Structure Generation (CSG) problem requires finding an optimal partition of a set of n agents. An optimal partition means one that maximizes global welfare. Computing an optimal coalition structure is computationally hard especially when there are externalities, i.e., when the worth of a coalition is dependent on the organisation of agents outside the coalition. A number of algorithms were previously proposed to solve the CSG problem but most of these methods were designed for systems without externalities. Very little attention has been paid to finding optimal coalition structures in the presence of externalities, although externalities are a key feature of many real world multiagent systems. Moreover, the existing methods, being non-heuristic, have exponential time complexity which means that they are infeasible for any but systems comprised of a small number of agents. The aim of this research is to develop effective heuristic methods for finding optimal coalition structures in systems with externalities, where time taken to find a solution is more important than the quality of the solution. To this end, four different heuristics methods namely tabu search, simulated annealing, ant colony search and particle swarm optimisation are explored. In particular, neighbourhood operators were devised for the effective exploration of the search space and a compact representation method was formulated for storing details about the multiagent system. Using these, the heuristic methods were devised and their performance was evaluated extensively for a wide range of input data.

In this thesis, a Particle Swarm Optimization (PSO) method combined with a ray propagation method is presented as a means to optimally locate multiple antennas in an indoor environment. This novel approach uses Particle Swarm Optimisation combined with geometric partitioning. The PSO algorithm uses swarm intelligence to determine the optimal transmitter location within the building layout. It uses the Keenan-Motley indoor propagation model to determine the fitness of a location. If a transmitter placed at that optimum location, transmitting a maximum power is not enough to meet the coverage requirements of the entire indoor space, then the space is geometrically partitioned and the PSO initiated again independently in each partition. The method outputs the number of antennas, their effective isotropic radiated power (EIRP) and physical location required to meet the coverage requirements. An example scenario is presented for a real building at Loughborough University and is compared against a conventional planning technique used widely in practice.

A ocorrência de derrames basálticos continentais assim como enxames de diques a estes relacionados tem sido correlacionada ao impacto de uma pluma mantélica na base da litosfera, ao afinamento crustal e à fragmentação de continentes. Um outro modelo sugere que a ascensão do material magmático ocorre por descontinuidades na litosfera não sendo necessária assim a ocorrência de uma pluma mantélica. Na região entre Resende e a Baía da Ilha Grande, localizada no Estado do Rio de Janeiro, Região Sudeste do Brasil, foram cartografados aproximadamente 140 corpos magmáticos (diques e sills), correlacionados à fragmentação do Gondwana que teve seu ponto máximo a aproximadamente 120 Ma. Estes corpos, em conjunto com outros em outras regiões do Estado do Rio de Janeiro, fazem parte do Enxame de Diques da Serra do Mar. Os corpos cartografados são, em sua maioria, diques e subordinadamente sills que formam três diferentes grupos com base na orientação espacial: NW, NS e NE. A petrografia indicou que estes são formados por basalto, basalto porfirítico, diabásio e micro-gabro sendo a constituição mineralógica formada por fenocristais de olivina, augita e plagioclásio e uma matriz composta por augita, pigeonita, plagioclásio, minerais opacos, apatita, quartzo, clorita e saussurita. Os diques e sills fazem parte de uma série transicional de afinidade toleítica sendo composta por quartzo toleítos classificados como basalto, basalto andesítico, traquibasalto e basalto traquiandesítico. Os toleítos apresentam teores médios de MgO de 4,1% (peso) e teores médios de TiO2 de 3,70% (peso). Com base na razão (La/Yb)n e em outras razões de elementos traços, foi sugerida a ocorrência de três suítes magmáticas distintas: 1) Suíte A (La/Yb)n entre 7,20 e 11; 2) Suíte B (La/Yb)n entre 11,6 e 17,7; 3) Suíte C (La/Yb)n entre 24,8 e 32,6. A análise de diagramas bivariantes, multielementares e de elementos traços, sugriu que o provável processo evolutivo destas suítes foi a cristalização fracionada com o envolvimento de uma fonte do tipo enriquecida com pelo menos uma participação do manto litosférico subcontinental. Análises geocronológicas 40Ar/39Ar dos corpos da área alvo indicaram idades localizadas no intervalo entre 126,34,5 e 155,44,6 Ma, com a distribuição média das idades situada no intervalo entre 134-145 Ma, sendo portanto um pouco mais antigas se comparadas as idades de outras áreas do Enxame de Diques da Serra do Mar. A comparação da orientação espacial dos diques da área alvo com outras áreas do Enxame de Diques da Serra do Mar revelou que somente os diques NE apresentam direções coincidentes tanto com a estruturação do embasamento quanto com a dos outros diques que fazem parte do Enxame. Os corpos com direção NW e NS, abundantes na área alvo são raramente reportados em outras áreas, sugerindo que para área alvo a ocorrência de estruturas NW e NS, como por exemplo falhas e fraturas, exerceram um controle maior no processo de intrusão do que a estruturação NE do embasamento. Em relação a litogeoquímica, as comparações efetuadas com outras área do Enxame de Diques da Serra do Mar e da Província Magmática do Paraná, indicou que este padrão de mais uma suíte magmática é comum em toda área do enxame, porém não são reportadas razões (La/Yb)n tão altas quanto as apresentadas pela Suíte A. Os magmas das suítes da área alvo correlacionam-se algumas vezes com os magmas do tipo Urubici e outras com os do tipo Pitanga podendo ser representante de um tipo hibrido não representado na Província Magmática do Paraná, mas que seria semelhante ao magma do tipo Paraíba encontrado no Enxame de Diques da Serra do Mar. As idades mais antigas que a média normalmente encontrada para os diques que fazem parte do Enxame de Diques da Serra do Mar sugere que processos distensionais associados à fragmentação do Gondwana já estariam atuando na região sudeste do Brasil há pelo menos 150 Ma. / Continental flood basalts and Dike Swarms usually are correlated with the impact of a mantle plume at the base of the lithosphere and continental break-up. In the area located between Resende and Ilha Grande Bay, Rio de Janeiro State, southeast of Brazil, approximately 170 igneous rocks bodies (dikes and sills) were mapped and are correlated with the Gondwana break-up 120 My. The dikes and sills are part of the Serra do Mar Dike Swarm which occur in the coastline and interior areas of the Rio de Janeiro and São Paulo State. The basement rocks are Precambrian gneiss. These magmatic bodies are mostly dikes and few sills, and were divided in three groups based on orientation: NW, NS and NE. Petrography showed that these bodies are basalts, porphiritic basalts, diabases and gabbros. Their mineralogy includes olivine, augite and plagioclase, as phenocrysts, and augite, pigeonite, plagioclase, opaque minerals, apatite, quartz, chlorite and saussurite, as groundmass. These rocks are part of a tholeiitic transitional magmatic serie, classified as basalts, trachy basalts, basaltic trachyandesites and basaltic andesite. The MgO average in these rocks is 4.1 % and they were classified as high-TiO2 (average of 3.70%). Based on (La/Yb)n, samples are separated in 3 groups: 1) Suite A (La/Yb)n between 7,20 e 11; 2) Suite B (La/Yb)n between 11,6 e 17,7; 3) Suíte C (La/Yb)n between 24,8 e 32,6. Fractional crystallization with sublithospheric mantle source is the most probable evolutive process for those dikes. Comparison between these dikes and Paraná Magmatic Province indicates that the tholeiitic basalts in this work area are similar to Urubici and Pitanga magmas and also similar to Paraíba magma in the other areas of Serra do Mar Dike Swarm. 40Ar/39Ar geochronology for these rocks reveled ages between 126, 3 4,5 and 155,4 4,6 Ma. Clustering is in the interval between 134 145 Ma. The comparison of spatial orientation, geochemistry and geochronology data with other areas, suggests that distensive process started at 150Ma in the southeast region of Brazil before the Gondwana break-up.

Orientadora: Plácida Leopoldina Ventura Amorim da Costa Santos / Banca: Ricardo César Gonçalves Sant'Ana / Banca: Silvana Aparecida Borsetti Gregório Vidotti / Banca: Marcos Luiz Mucheroni / Banca: Rogério Aparecido Sá Ramalho / Resumo: Os estudos em inteligência coletiva têm revelado que as atividades dos indivíduos em grupos apresentam diferentes manifestações, as quais podem ser identificadas como compartilhamento, cooperação e ação coletiva. Defende-se como tese que quanto maior o nível de comprometimento de uma determinada comunidade, maiores as possibilidades da inteligência coletiva resultar em produção de conteúdo; quanto mais possibilidades de produção objetiva de conteúdo, maior a presença direta da Ciência da Informação, e quanto menos produção objetiva de conteúdo mais desafiadora é a atuação dessa ciência, uma vez que sua atenção será sobre os processos de informação. Dessa forma, pretende-se propor um arcabouço epistemológico para a reflexão da inteligência coletiva no âmbito dos estudos em Informação e Tecnologia. Para tanto, a partir de uma pesquisa exploratória, conduzida pelo aspecto bibliográfico, o estudo se propôs a investigar as diferentes manifestações da inteligência coletiva - o compartilhamento, a cooperação e a ação coletiva; definir um modelo para a análise de ambientes digitais que aparentam a cultivação da inteligência coletiva; compreender a trajetória evolutiva dos ambientes digitais que tiveram como foco a inteligência coletiva; analisar, mediante ao modelo criado, os ambientes digitais definidos. Os ambientes selecionados para análise foram o YouTube, Facebook e a Wikipédia. Observou-se que as manifestações analisadas são variáveis que compõem a inteligência coletiva, e que ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The studies in collective intelligence have revealed that the activities of individuals in groups present different manifestations, which can be identified as sharing, cooperation and collective action. It is defended as thesis that the greater the level of commitment of a determined community, the greater the possibilities of the collective intelligence result in the objective production of content; the more possibilities of objective production of content, the greater the direct presence of Information Science, and the less objective production of content more challenging is the performance of this science, since its attention will be on information processes. In this way, its intend to propose an epistemological framework for the reflection of collective intelligence in the scope of studies in Information and Technology. To do so, based on an exploratory research, steering by the bibliographical aspect, the study proposed to investigate the different manifestations of collective intelligence - sharing, cooperation and collective action; to define a model for the analysis of digital environments that appear to cultivate collective intelligence; to understand the evolutionary trajectory of digital environments that focused on collective intelligence; to analyze, through the created model, the defined digital environments. The environments selected for analysis were YouTube, Facebook, and Wikipedia. Its observed that the analyzed manifestations are variables that make up the ... (Complete abstract click electronic access below) / Doutor