Η αυτόματη ταυτοποίηση εικόνων δακτυλικών αποτυπωμάτων αποτελεί ένα δύσκολο και πολυδιάστατο πρόβλημα, το οποίο έχει απασχολήσει πλήθος ερευνητών και για το οποίο έχει αναπτυχθεί μεγάλος αριθμός τεχνικών. Η δυσκολία του προβλήματος έγκειται στο γεγονός ότι οι εικόνες των αποτυπωμάτων είναι σε μεγάλο ποσοστό αλλοιωμένες ή ακόμα σε κάποιες περιπτώσεις δεν είναι διαθέσιμη η πλήρης εικόνα του αποτυπώματος, αλλά μόνο ένα μέρος αυτής. Στη συγκεκριμένη διατριβή, προτείνονται δύο μέθοδοι αυτόματης ταυτοποίησης δακτυλικών αποτυπωμάτων: α) η μέθοδος ταυτοποίησης δακτυλικών αποτυπωμάτων με χρήση τεχνικών ευθυγράμμισης και β) μέθοδος ταυτοποίησης δακτυλικών αποτυπωμάτων από το συνδυασμό του Δικτύου Αυτό-Οργανούμενων Δικτύων του Kohonen και του ορισμού των σημείων μικρολεπτομερειών των αποτυπωμάτων ως νευρώνων του δικτύου. Επιπλέον, ιδιαίτερη βαρύτητα δόθηκε στην προεπεξεργασία των εικόνων των δακτυλικών αποτυπωμάτων βάσει της ανάπτυξης και εφαρμογής κατάλληλων τεχνικών επεξεργασίας εικόνων προκειμένου να προκύψει βελτίωση της ποιότητας της εικόνας του δακτυλικού αποτυπώματος και να εξαχθούν οι μικρολεπτομέρειες που χρησιμοποιούνται για την ταύτιση των δακτυλικών αποτυπωμάτων. Στο πλαίσιο της παρούσας διατριβής, χρησιμοποιήθηκαν δεδομένα δακτυλικών αποτυπωμάτων από τις βάσεις VeriFingerSample_DB της Neurotechnology και η DB3 του διαγωνισμού δακτυλικών αποτυπωμάτων FVC2004. Για την ποσοτική αποτίμηση της απόδοσης των προτεινόμενων μεθόδων χρησιμοποιήθηκε το κριτήριο της Αναλογίας Ίσου Σφάλματος (EqualErrorRate – EER). Σύμφωνα με το κριτήριο αυτό, η μέθοδος ταυτοποίησης δακτυλικών αποτυπωμάτων βάσει του Δικτύου Αυτό-Οργανούμενων Δικτύων παρείχε καλύτερα αποτελέσματα σε σύγκριση με οποιαδήποτε μέθοδο ευθυγράμμισης που εφαρμόστηκε. / Automatic Fingerprint Identification is a difficult and multidimensional problem. For this reason, the number of papers and techniques regarding this issue is numerous. The hardness of the problem lies with the fact that there is a large percentage of corrupted and partial fingerprint images. Throughout this Thesis, two methods were proposed for the Automatic Fingerprint Identification: a) the Automatic Fingerprint Identification based on registration techniques and b) the Automatic Fingerprint Identification based on the theory of Self Organizing Maps of Kohonen, setting the minutiae of the fingerprint images as input neurons of the Map. Furthermore, an important step prior to the application of the proposed automatic fingerprint identification methods is the pre-processing of these images by the development and implementation of a series of image processing techniques in order to enhance the image quality and to extract the minutiae which are then used for the fingerprint identification. In this Thesis, a substantial number of fingerprint images were used from the database VeriFingerSample_DB kai from the database DB3 of the competition FVC2004. The quantitative evaluation of both proposed automatic fingerprint identification methods were based on the Equal Error Rate (EER) criterion. According to this, the Automatic Fingerprint Identification based on the Self Organizing Maps outperformed against any other method based on registration techniques.

Thesis (MA)--Stellenbosch University, 2003. / ENGLISH ABSTRACT: The advent of the computer age has seen many fundamental changes in the economics. The ease with which organisations can store and transmit information in unprecedented quantities and speeds has changed the face of the economy as well as the way in which organisations conduct their day to day operations. Information has become the primary resource for organisational competitiveness and this has seen an increasing drive for efficient information generation and management in an economy that is interconnected on a global scale. The demand for better information management practices is driven by the realisation that the global economy is susceptible to sudden and unpredictable changes that can potentially have global consequences. The more information organisations have at their disposal, the better their chances are of remaining competitive and relevant in the global economy. The informational economy confronts organisations with two very significant problems, the first is information overload due to the sheer volume of information that is available to them. The second problem is that despite the volume of available information organisations still are not privy to all the information that is required to lessen the impact of uncertainty that is so characteristic of the global economy. Organisations therefore always run the' risk of becoming irrelevant if they do not change constantly. This drive for continuous change and the dependence on information has led some organisational theorists and economists to compare the global economy and organisations to nonlinear systems found in nature. Examples of nonlinear systems are living organisms, ecologies and solar systems. All of these systems are characterised by high levels of interconnectedness and interdependence among individual units within a shared environment, which they co-create. Nonlinear systems are of particular interest to organisational theorists because these systems process information about the environment to adapt in an unpredictable way to unpredictable changes. Such systems are incredibly resilient because they are able to learn and adapt to different conditions. Another notable aspect of nonlinear systems is the clear structured and complex organisation that they exhibit in the absence of centralised control mechanisms. Every unit has the liberty to experiment with new designs and from the success of individual units an organised and stable system emerges with a strong link between the success of individuals and the whole system. The order that exists within nonlinear systems is known as self-organisation because it is not superimposed but emerges instead in a spontaneous manner. Nonlinear systems are therefore more than just the sum of their parts. The notion of nonlinear systems and self-organisation has seen authors such as Stacey, Wheatley and Senge develop new ideas about organisational development, leadership and organisational strategic thinking. Their ideas are based on what is popularly known as 'The New Science'. These ideas attempt to encourage organisations realise that the global economy functions as a nonlinear system and that organisations stand a better chance of success if they learn to understand the principles of nonlinear systems and to utilise the inherent creative and organising characteristics of such systems. / AFRIKAANSE OPSOMMING: Die aanvang van die rekenaar era het verskeie fundamentele veranderinge in ekonomie mee gebring. Die gemak en snelheid waarmee organisasies informasie kan stoor en versprei is ongekend en het terselfde tyd die voorkoms van die ekonomie verander asook die wyse waarop organisasies op 'n daaglikse basis funksioneer. Informasie het die belangrikste hulpbron geword vir organisasies in terme van kompetering en dit het 'n groter dryfkrag vir doeltreffende informasie ontginning en bestuur mee gebring in 'n ekonomie wat op 'n wereldwye skaal in mekaar gevleg is. Die aanvraag vir beter informasie bestuur praktyke word gedryf deur die wete dat die wereld ekonomie vatbaar is vir skielike en onvoorspelbare veranderinge wat potensieel 'n wereldwye impak kan he. Hoe meer informasie organisasies tot hul beskikking het hoe beter is hul kans om relevant en kompeterend te bly in die wereld ekonomie. Die informasie ekonomie konfronteer organisasies met twee fundamentele probleme. Die eerste gevaar is dat organisasies oorlaai kan word met informasie as gevolg van die absolute volume van beskikbare informasie. Die tweede probleem spruit voort uit die feit dat ten spyte van die beskikbare informasie, lei organisasies steeds aan 'n gebrek aan algehele informasie, organisasies kan dus nooit toegang he tot al die informasie wat benodig word om die impak te verminder van die onsekerheid wat so kenmerkend is van die wereld ekonomie. Organisasies loop dus altyd die gevaar om irrelevant te raak as hulle nie konstant aanpas by nuwe omstandighede nie. Hierdie soeke na konstante verandering en die afhanklikheid op informasie het verskeie organisasie teoretici en ekonome daartoe gelei om 'n vergelyking te tref tussen die wereld ekonomie en organisasies aan die een kant en nie-Iiniere sisteme wat in die natuur voorkom. Voorbeelde van sulke sisteme sluit lewende organismes, ekostelsels en sterre stelsels in. Die komponente van al hierdie sisteme is op 'n komplekse wyse inmekaar geweef en interafhanklik op mekaar binne die raamwerk van gemeenskaplike omgewing waarvoor hierdie komponente mede verantwoordelik is. Nie-liniere sisteme is van besondere belang vir organisasie teoretici omdat die betrokke sisteme informasie verwerk aangaande hul omgewing om op 'n onvoorspelbare wyse aan te pas by onvoorspelbare veranderinge in die omgewing. Sulke sisteme is uitsonderlik standvastig deurdat hulle kan leer en aanpas by verskillende omstandighede. Nog 'n merkbare aspek van sulke sisteme is die duidelik gestruktureerde en komplekse organisasie wat bestaan ten spyte van 'n algehele gebrek aan gesentraliseerde beheer meganismes. Elke komponent is vry om met 'n nuwe ontwerp te eksperimenteer en vanuit die sukses van die komponente spruit die sukses van die sisteem. Die organisasie wat sigbaar is in nie-liniere sisteme staan bekend as self-organisasie omdat dit nie voortspruit uit 'n sentrale beheer meganisme nie maar instede spontaan onstaan as 'n gevolg van die aksies van komponente. Nie-Iiniere sisteme het die potensiaal om meer te kan wees as die somtotaal van hul komponente. Die beginsel van nie-liniere sisteme en selforganisasie het skrywers soos Stacey, Wheatley en Senge daartoe gelei om nuwe idees te ontwikkel rakende organisasie ontwikkeling, leierskap en strategiese beplanning in organisasies. Hierdie idees is gegrond in wat algemeen bekend staan as 'The New Science'. Die idees van hierdie skrywers is gemik daarop om organisasies aan te moedig om raak te sien dat die wereld ekonomie soos 'n nie-liniere sisteem funksioneer en dat organisasies as sulks 'n beter kans staan om sukses te behaal as hulle sou leer om die beginsels van nie-liniere sisteme te begryp en die inherente kreatiewe en organiserings eienskappe van sulke sisteme uit te buit.

O presente trabalho é resultado da colaboração de pesquisadores do Centro de Engenharia Nuclear (CEN) e de pesquisadores do Centro de Biotecnologia (CB), ambos pertencentes ao IPEN, para o desenvolvimento de uma metodologia que visa auxiliar os profissionais citogeneticistas fornecendo uma ferramenta que automatize parte da rotina necessária para a avaliação qualitativa e quantitativa de danos biológicos em termos de aberração cromossômica. A técnica citogenética, sobre a qual esta ferramenta é desenvolvida, é a técnica de aberrações cromossômicas. Nela, são realizadas preparações citológicas de linfócitos de sangue periférico para que metáfases sejam analisadas e fotografadas ao microscópio e, com base na morfologia dos cromossomos, anomalias sejam investigadas. Quando esta tarefa é realizada manualmente, os cromossomos são analisados visualmente um a um pelo profissional citogeneticista, logo, trata-se de um processo minucioso em virtude da variação geral na aparência do cromossomo, do seu tamanho pequeno e do grande número de cromossomos por célula. Para um diagnóstico confiável, é necessário que várias células sejam analisadas, tornando-se uma tarefa repetitiva e demorada. Neste contexto, foi proposto o uso dos mapas auto-organizáveis para o reconhecimento automático de padrões morfológicos referentes às imagens de cromossomos humanos. Para isso, foi desenvolvido um método de extração de características por meio do qual é possível classificar os cromossomos em: dicêntricos, anéis, acrocêntricos, submetacêntricos e metacêntricos, com acerto de 93,4 % em relação ao diagnóstico dado por um profissional citogeneticista. / This work is a joint collaboration between Nuclear Energy Research Institute (IPEN), Nuclear Engineering Center and Biotechnology Center to develop a methodology aiming to assist cytogenetic professionals by providing a tool to automate part of the required routine to perform qualitative and quantitative evaluation of biological damage in terms of chromosomal aberration. The cytogenetic technique upon which this tool was developed, is the chromosome aberrations technique, in which cytological preparations of peripheral blood lymphocyte metaphases are performed to be analyzed and photographed under a microscope in order to investigating chromosomal aberration. Performed manually, the chromosomes are analyzed visually one by one by a cytogenetic professional, so it is a painstaking process due to the great deal of variation in the appearance of each chromosome, their small sizes and not to mention the high density of chromosomes per cell. In order to obtain a reliable diagnosis it is necessary that many cells be analyzed, which makes this a repetitive and time consuming process. In this context, the use of self-organizing maps for the automatic recognition of patterns relating to morphological pictures of human chromosomes has been proposed. For this, we developed a feature extraction method by which is possible to classify chromosomes in: dicentrics, ring-shaped, acrocentric, submetacentric and metacentric with 93.4% accuracy compared to diagnostic given by a professional cytogeneticist.

A construção e ampliação de rodovias gera impactos significativos ao meio ambiente. Os principais impactos ao meio biótico são a supressão de vegetação, redução da riqueza e abundância de espécies de fauna como decorrência da fragmentação de habitats e aumento dos riscos de atropelamento de animais silvestres e domésticos. O objetivo geral do trabalho foi identificar padrões espaciais nos atropelamentos de fauna silvestre por espécie (nome popular) utilizando ferramentas de análise espacial e machine learning. Especificamente, buscou-se compreender a relação entre atropelamentos de animais silvestres e variáveis que representam características de uso e cobertura do solo e caracterização da rodovia, tais como formação florestal, corpos d\'água, silvicultura, áreas edificadas, velocidade máxima permitida, volume de tráfego, entre outras. Os atropelamentos de fauna silvestre foram analisados por espécie atropelada, a fim de identificar os padrões espaciais dos atropelamentos específicos para cada espécie. As ferramentas de análise espacial empregadas foram a Função K - para determinar o padrão de distribuição dos registros de atropelamento de fauna, o Estimador de Densidade de Kernel - para gerar estimativas de densidade de pontos sobre a rodovia, a Análise de Hotspots - para identificar os trechos mais críticos de atropelamento de fauna e, por fim, o Self-Organizing Maps (SOM), um tipo de rede neural artificial, que reorganiza amostras de dados n-dimensionais de acordo com a similaridade entre elas. Os resultados das análises de padrões pontuais foram importantes para entender que os pontos de atropelamento possuem padrões de distribuição espacial que variam por espécie. Os eventos ocorrem espacialmente agrupados e não estão homogeneamente distribuídos ao longo da rodovia. De maneira geral, os animais apresentam trechos de maior intensidade de atropelamento em locais distintos. O SOM permitiu analisar as relações entre múltiplas variáveis, lineares e não-lineares, tais como são os dados ecológicos, e encontrar padrões espaciais distintos por espécie. A maior parte dos animais foi atropelada próxima de fragmentos florestais e de corpos d\'água, e distante de cultivo de cana-de-açúcar, silvicultura e área edificada. Porém, uma parte considerável das mortes de animais dos tipos com maior número de atropelamentos ocorreu em áreas com paisagem diversificada, incluindo alta densidade de drenagem, fragmentos florestais, silvicultura e áreas edificadas. / The construction and expansion of roads cause significant impacts on the environment. The main potential impacts to biotic environment are vegetation suppression, reduction of the abundance and richness of species due to forest fragmentation and increase of animal (domestic and wildlife) vehicle collisions. The general objective of this work was to identify spatial patterns in wildlife-vehicle collisions individually per species by using spatial analysis and machine learning. Specifically, the relationship between wildlife-vehicle collisions and variables that represent land use and road characterization features - such as forests, water bodies, silviculture, sugarcane fields, built environment, speed limit and traffic volume - was investigated. The wildlife-vehicle collisions were analyzed per species, in order to identify the spatial patterns for each species separately. The spatial analysis tools used in this study were K-Function - to determine the distribution pattern of roadkill, Kernel Density Estimator (KDE) - to identify the location and intensity of hotspots and hotzones. Self-Organizing Maps (SOM), an artificial neural network (ANN), was selected to reorganize the multi-dimensional data according to the similarity between them. The results of the spatial pattern analysis were important to perceive that the point data pattern varies between species. The events occur spatially clustered and are not uniformly distributed along the highway. In general, wildlife-vehicle collsions have their hotzones in different locations. SOM was able to analyze the relationship between multiple variables, linear and non-linear, such as ecological data, and established distinct spatial patterns per each species. Most of the wildlife was run over close to forest area and water bodies, and distant from sugarcane, silviculture and built environments. But a considerable part of the wildlife-vehicle collisions occurred in areas with diverse landscape, including high density of water bodies, silviculture and built environments.

This research created a new theoretical Soft Computing (SC) hybridized network intrusion detection diagnostic system including complex hybridization of a 3D full color Self-Organizing Map (SOM), Artificial Immune System Danger Theory (AISDT), and a Fuzzy Inference System (FIS). This SOM+ diagnostic archetype includes newly defined intrusion types to facilitate diagnostic analysis, a descriptive computational model, and an Invisible Mobile Network Bridge (IMNB) to collect data, while maintaining compatibility with traditional packet analysis. This system is modular, multitaskable, scalable, intuitive, adaptable to quickly changing scenarios, and uses relatively few resources.

166f. / Submitted by Suelen Reis (suziy.ellen@gmail.com) on 2013-04-10T19:35:07Z No. of bitstreams: 1 Luciana Pacheco seg.pdf: 3529890 bytes, checksum: 13857ac04543f1bbc9fd4d7ed9849eba (MD5) / Approved for entry into archive by Rodrigo Meirelles(rodrigomei@ufba.br) on 2013-05-11T15:30:28Z (GMT) No. of bitstreams: 1 Luciana Pacheco seg.pdf: 3529890 bytes, checksum: 13857ac04543f1bbc9fd4d7ed9849eba (MD5) / Made available in DSpace on 2013-05-11T15:30:28Z (GMT). No. of bitstreams: 1 Luciana Pacheco seg.pdf: 3529890 bytes, checksum: 13857ac04543f1bbc9fd4d7ed9849eba (MD5) Previous issue date: 2011 / Em sistemas industriais automatizados, a inatividade provocada pela escassez não planejada de recursos, ou por falhas de processo, tem grande influência no desempenho dos sistemas por conta das descontinuidades e instabilidades geradas. Sistemas de controle distribuídos e autônomos podem ajudar a lidar com esses tipos de problemas devido à melhoria de desempenho possibilitada. Entretanto, aspectos relativos à segurança e ao tempo de resposta devem ser bem tratados nesses sistemas devido aos riscos envolvidos (humanos, financeiros e ambientais). A proposta de sistemas autônomos e distribuídos visa a que decisões de controle sejam tomadas mais próximas do objeto controlado, reduzindo assim o tempo de atuação no processo e sistematizando algumas decisões, antes tomadas de forma empírica. Consequentemente, se espera aumentar a disponibilidade e a continuidade do processo, bem como garantir os aspectos de confiabilidade. Entretanto, quando tais sistemas se tornam mais autônomos e distribuídos, podem tender ao comportamento global caótico, caso suas interações não estejam bem definidas. Assim, é importante que seja avaliado e dimensionado o acoplamento entre os sistemas autônomos relacionados. O grau de inteligência de um sistema pode variar de uma entidade completamente controlada a entidades completamente autônomas. O primeiro nível de inteligência é verificado quando um sistema é capaz de gerenciar suas próprias informações, obtidas por meio de sensores e demais técnicas e dispositivos, e não somente manipular informações. Em um segundo nível, o sistema pode notificar o seu gestor quando há um problema. Em um terceiro nível, o sistema já é capaz de tomar decisões e se autogerenciar, mesmo sem intervenção externa. Neste caso, o sistema tem controle total sobre suas tarefas e não há nenhum controle externo a ele. A alternativa proposta pelo GCAD visa a que Sistemas Industriais Automatizados atinjam até o terceiro nível de inteligência, sendo que intervenções externas podem ser admitidas nos casos em que uma ação puramente local e autônoma de fato não é recomendável ou não é possível, por exemplo, havendo necessidade de substituição de equipamentos ou dispositivos. O GCAD propõe um módulo de controle inteligente instanciado predominantemente em nível local que visa a permitir que cada Sistema Industrial Automatizado, distribuído em células, tome decisões críticas de uma forma autônoma. Adicionalmente, um módulo remoto deve gerenciar situações mais complexas que estão além da capacidade de decisão ou atuação do sistema de controle local. O modelo proposto visa a permitir ajustes automáticos e autônomos no sistema, a fim de melhorar seu desempenho, e prevenir ou tratar as falhas inesperadas,assegurando a continuidade da operação. / Salvador

A análise de sinais provenientes de um eletrocardiograma (ECG) pode ser de grande importância para avaliação do comportamento cardíaco de um paciente. Os sinais de ECG possuem características específicas de acordo com os tipos de arritmias e sua classificação depende da morfologia do sinal. Neste trabalho é considerada uma abordagem híbrida utilizando análise de componentes principais (PCA) e mapas auto-organizáveis (SOM) para classificação de agrupamentos provenientes de arritmias como a taquicardia sinusal e, principalmente, fibrilação atrial. Nesse sentido, O PCA é utilizado como um pré-processador buscando suprimir sinais de atividades ventriculares, de maneira que a atividade atrial presente no ECG seja evidenciada sob a forma das ondas f. A Rede Neural SOM, é usada na classificação dos padrões de fibrilação atrial e seus agrupamentos / A análise de sinais provenientes de um eletrocardiograma (ECG) pode ser de grande importância para avaliação do comportamento cardíaco de um paciente. Os sinais de ECG possuem características específicas de acordo com os tipos de arritmias e sua classificação depende da morfologia do sinal. Neste trabalho é considerada uma abordagem híbrida utilizando análise de componentes principais (PCA) e mapas auto-organizáveis (SOM) para classificação de agrupamentos provenientes de arritmias como a taquicardia sinusal e, principalmente, fibrilação atrial. Nesse sentido, O PCA é utilizado como um pré-processador buscando suprimir sinais de atividades ventriculares, de maneira que a atividade atrial presente no ECG seja evidenciada sob a forma das ondas f. A Rede Neural SOM, é usada na classificação dos padrões de fibrilação atrial e seus agrupamentos

Network Direct Selling Organisations (NDSOs) exist in more than 50 countries and have more than 74 million members. The most recent statistical information reveals that the vast majority of members do not earn significant income. Criticism of these organisations revolves around the ethicality of consumption, the commercialisation of personal relationships, and the exploitation of unrealistic expectations. This study aims to explore how communication creates networks that sustain an industry of this kind despite the improbability of its existence. The study commences with a description of NDSOs from historical, operational, tactical, and strategic perspectives. Given the broader context created by the global presence of this industry, cybernetics has been selected as a meta-theoretical perspective for the study of communication. The more recent development of second-order cybernetics and social autopoiesis are introduced to communication theory as a field. Niklas Luhmann‟s new social theory of communication is assessed and applied in relation to existing communication theory. New conceptual models are developed to explore communication as the unity of the synthesis of information, utterance, understanding, and expectations as selections that occur both consciously and unconsciously, intentionally and unintentionally. These models indicate the multiplexity of individual and social operationally closed, yet informationally open systems, and they are used here to provide a systemic and coherent alternative to orthodox communication approaches to the study of organisations. The study adopts a constructivist epistemological stance and propounds throughout the necessity of further interdisciplinary collaboration. The study concludes that individuals are composite unities of self-creating systems, and they co-create social systems by self-creating and co-creating meaning. Meaning is described as the continuous virtualisation and actualisation of potentialities that in turn coordinate individual and social systems‟ actions. A communication process flow model is created to provide a theoretical explanation for the existence of NDSOs as self-creating systems. The study aims to show that communication has arguably become the most pervasive discipline as a result of the globally interactive era. It is shown that second-order cybernetics and social autopoiesis raise several further questions to be explored within communication theory as a field. / Communication, first-order cybernetics, second-order cybernetics, Complexity and complex systems, autopoiesis, self-reference, recursivity, operational closure, system boundaries, Network Direct Selling Organisations / Communication / D. Litt. et Phil. (Communication)

SILVA, Ana Cristina Cunha da. O uso de redes neurais auto-organizáveis na análise da transferência de conhecimentos prosódico em aprendizes brasileiros de língua inglesa. 2010, 201f. Tese (Doutorado em Linguística) – Universidade Federal do Ceará, Departamento de Letras Vernáculas, Programa de Pós-graduação em Linguística, Fortaleza-CE, 2010. / Submitted by nazareno mesquita (nazagon36@yahoo.com.br) on 2012-06-28T13:08:58Z No. of bitstreams: 1 2010_tese_ACCSilva.pdf: 2172197 bytes, checksum: 036ba2cdc331410f0516a0ba2abe520d (MD5) / Approved for entry into archive by Maria Josineide Góis(josineide@ufc.br) on 2013-10-10T13:22:45Z (GMT) No. of bitstreams: 1 2010_tese_ACCSilva.pdf: 2172197 bytes, checksum: 036ba2cdc331410f0516a0ba2abe520d (MD5) / Made available in DSpace on 2013-10-10T13:22:45Z (GMT). No. of bitstreams: 1 2010_tese_ACCSilva.pdf: 2172197 bytes, checksum: 036ba2cdc331410f0516a0ba2abe520d (MD5) Previous issue date: 2010 / The objective of this dissertation was to investigate how the prosodic knowledge is organized in an early stage of L2 acquisition in Brazilian learners of English with the help of a connectionist neural network. The approach proposed in this research is first, to quantify the utterances of L2 learners in the form of LPC coefficients and other linguistic/phonetics features that can represent the phenomenon studied here (Transfer of the prosodic knowledge from Portuguese to English). This process is called speech feature extraction, an important step in the connectionist approach to speech processing. Second, since certain features of the lexical item or sentence produced by each learner are determined, these data are entered into the neural network to analyze the statistical properties (regularities) of the set of speakers as a whole. Third, visualization tools are used to analyze how the network organizes speakers and what information is most relevant to this process of group formation (e.g. proficiency level, a certain characteristic or property of speech, among others). The network is known as Self-Organizing Map (Self-Organizing Map, SOM). The SOM organizes speakers for similarity degree in well-defined groups (clusters). Application of SOM in this context is therefore innovative. The SOM network is implemented in Matlab environment using the SOMtoolbox package, which is a set of programming routines developed by the research group in Finland, also the inventors of the SOM. The simulation results indicate that SOM might be used more frequently to assess the degree of distance that a group of learners is to the group of native speakers. Thus, a neural network might be used as a tool in the context of determining the level of foreign language proficiency. / O objetivo desta tese foi investigar como o conhecimento prosódico está organizado em um estágio inicial de aquisição de L2 em aprendizes brasileiros de inglês com a ajuda de uma rede neural conexionista. A abordagem proposta neste trabalho consiste primeiramente em "quantificar" as elocuções dos aprendizes de L2 na forma de coeficientes LPC e outras características linguísticas/fonéticas que possam representar o fenômeno aqui estudado (Transferência do Conhecimento Prosódico do Português para o inglês). A este processo dá-se o nome de "extração de características" da fala (feature extraction), uma importante etapa na abordagem conexionista do processamento da fala. Em segundo lugar, uma vez determinadas as características do item lexical ou da frase produzida por cada aprendiz, são inseridos esses dados na rede neural a fim de analisar as propriedades (regularidades) estatísticas do conjunto de falantes como um todo. Em terceiro, utiliza-se ferramentas de visualização para analisar como a rede organiza os falantes e quais informações são mais relevantes para este processo de formação de grupos (e.g. nível de proficiência, uma certa característica ou propriedade da fala, entre outros). A rede utilizada é conhecida como Mapa Auto-Organizável (Self-Organizing Map, SOM). A rede SOM organiza os falantes por grau de similaridade em grupos bem definidos (clusters). A aplicação da rede SOM neste contexto é, portanto, inovadora. A rede SOM é implementada no ambiente Matlab usando o pacote Som toolbox, que é um conjunto de rotinas de programação desenvolvidas pelo grupo de pesquisa da Finlândia, também inventores da rede SOM. Os resultados das simulações apontam que a rede SOM pode vir a ser usada mais frequentemente para avaliar o grau de distância a que um grupo de aprendizes está do grupo de falantes nativos. Dessa forma, uma rede neural pode vir a ser aplicada como ferramenta no contexto de determinação de nível de proficiência em língua estrangeira.

Un des défis majeurs pour le développement des Systèmes Multi-Agents (SMA) auto-organisateurs est de garantir la convergence du système vers la fonction globale attendue par un observateur externe et de garantir que les agents sont capables de s'adapter face aux perturbations. Dans la littérature, plusieurs travaux se sont basés sur la simulation et le model-checking pour analyser les SMA auto-organisateurs. La simulation permet aux concepteurs d'expérimenter plusieurs paramètres et de créer certaines heuristiques pour faciliter la conception du système. Le model-checking fournit un support pour découvrir les blocages et les violations de propriétés. Cependant, pour faire face à la complexité de la conception des SMA auto-organisateurs, le concepteur a également besoin de techniques qui prennent en charge non seulement la vérification, mais aussi le processus de développement lui-même. En outre, ces techniques doivent permettre un développement méthodique et faciliter le raisonnement sur divers aspects du comportement du système à différents niveaux d'abstraction. Dans cette thèse, trois contributions essentielles ont été apportées dans le cadre du développement et la vérification formelle des SMA auto-organisateurs: une formalisation à l'aide du langage B-événementiel des concepts clés de ces systèmes en trois niveaux d'abstraction (micro, méso et macro), une expérimentation d'une stratégie de raffinement descendante pour le développement des SMA auto-organisateurs et la proposition d'un processus de raffinement ascendant basé sur des patrons de raffinement. / A major challenge for the development of self-organizing MAS is to guarantee the convergence of the system to the overall function expected by an external observer and to ensure that agents are able to adapt to changes. In the literature, several works were based on simulation and model-checking to study self-organizing MAS. The simulation allows designers to experiment various settings and create some heuristics to facilitate the system design. Model checking provides support to discover deadlocks and properties violations. However, to cope with the complexity of self-organizing MAS, the designer also needs techniques that support not only verification, but also the development process itself. Moreover, such techniques should support disciplined development and facilitate reasoning about various aspects of the system behavior at different levels of abstraction. In this thesis, three essential contributions were made in the field of formal development and verification of self-organizing MAS: a formalization with the Event-B language of self-organizing MAS key concepts into three levels of abstraction, an experimentation of a top-down refinement strategy for the development of self-organizing MAS and the definition of a bottom-up refinement process based on refinement patterns.