Contribuições a técnicas de agrupamento e visualização de dados multivariados utilizando mapas auto-organizáveis

Self-organizing maps (SOM) are artificial neural networks widely used in the data mining field, mainly because they constitute a dimensionality reduction technique given the fixed grid of neurons associated with the network. In order to properly the partition and visualize the SOM network, the various methods available in the literature must be applied in a post-processing stage, that consists of inferring, through its neurons, relevant characteristics of the data set. In general, such processing applied to the network neurons, instead of the entire database, reduces the computational costs due to vector quantization. This work proposes a post-processing of the SOM neurons in the input and output spaces, combining visualization techniques with algorithms based on gravitational forces and the search for the shortest path with the greatest reward. Such methods take into account the connection strength between neighbouring neurons and characteristics of pattern density and distances among neurons, both associated with the position that the neurons occupy in the data space after training the network. Thus, the goal consists of defining more clearly the arrangement of the clusters present in the data. Experiments were carried out so as to evaluate the proposed methods using various artificially generated data sets, as well as real world data sets. The results obtained were compared with those from a number of well-known methods existent in the literature

Uma Aplicação de Redes Neurais Auto-Organizaveis à Reconstrução Tridimensional de Superfícies

We propose a multi-resolution approach for surface reconstruction from clouds of unorganized points representing an object surface in 3D space. The proposed method uses a set of mesh operators and simple rules for selective mesh refinement, with a strategy based on Kohonen s self-organizing map. Basically, a self-adaptive scheme is used for iteratively moving vertices of an initial simple mesh in the direction of the set of points, ideally the object boundary. Successive refinement and motion of vertices are applied leading to a more detailed surface, in a multi-resolution, iterative scheme. Reconstruction was experimented with several point sets, induding different shapes and sizes. Results show generated meshes very dose to object final shapes. We include measures of performance and discuss robustness.

Processamento Inteligente de Sinais de Pressão e Temperatura Adquiridos Através de Sensores Permanentes em Poços de Petróleo

Originally aimed at operational objectives, the continuous measurement of well bottomhole pressure and temperature, recorded by permanent downhole gauges (PDG), finds vast applicability in reservoir management. It contributes for the monitoring of well performance and makes it possible to estimate reservoir parameters on the long term. However, notwithstanding its unquestionable value, data from PDG is characterized by a large noise content. Moreover, the presence of outliers within valid signal measurements seems to be a major problem as well. In this work, the initial treatment of PDG signals is addressed, based on curve smoothing, self-organizing maps and the discrete wavelet transform. Additionally, a system based on the coupling of fuzzy clustering with feed-forward neural networks is proposed for transient detection. The obtained results were considered quite satisfactory for offshore wells and matched real requisites for utilization

Contribuições de modelagem de equações estruturais na análise de dados em modelos comportamentais de destino turístico

A fragilidade brasileira quanto à competitividade turística é um fato observável nos dados da Organização Mundial do Turismo. O Brasil caiu em 2011, da 45ª para a 52ª posição, apesar de liderar no atributo recursos naturais e estar colocado na 23° em recursos culturais. Assim, grandes interesses e esforços têm sido direcionados para o estudo da competitividade dos produtos e destinos turísticos. O destino turístico é caracterizado por um conjunto complexo e articulado de fatores tangíveis e intangíveis, apresentando alta complexidade, dados de elevada dimensionalidade, não linearidade e comportamento dinâmico, tornando-se difícil a modelagem desses processos por meio de abordagens baseadas em técnicas estatísticas clássicas. Esta tese investigou modelos de equações estruturais e seus algoritmos, aplicados nesta área, analisando o ciclo completo de análise de dados, em um processo confirmatório no desenvolvimento e avaliação de um modelo holístico da satisfação do turista; na validação da estrutura do modelo de medida e do modelo estrutural, por meio de testes de invariância de múltiplos grupos; na análise comparativa dos métodos de estimação MLE, GLS e ULS para a modelagem da satisfação e na realização de segmentação de mercado no setor de destino turístico utilizando mapas auto-organizáveis de Kohonen e sua validação com modelagem de equações estruturais. Aplicações foram feitas em análises de dados no setor de turismo, principal indústria de serviços do Estado do Rio Grande do Norte, tendo sido, teoricamente desenvolvidos e testados empiricamente, modelos de equações estruturais em padrões comportamentais de destino turístico. Os resultados do estudo empírico se basearam em pesquisas com a técnica de amostragem aleatória sistemática, efetuadas em Natal-RN, entre Janeiro e Março de 2013 e forneceram evidências sustentáveis de que o modelo teórico proposto é satisfatório, com elevada capacidade explicativa e preditiva, sendo a satisfação o antecedente mais importante da lealdade no destino. Além disso, a satisfação é mediadora entre a geração da motivação da viagem e a lealdade do destino e que os turistas buscam primeiro à satisfação com a qualidade dos serviços de turismo e, posteriormente, com os aspectos que influenciam a lealdade. Contribuições acadêmicas e gerenciais são mostradas e sugestões de estudo são dadas para trabalhos futuros.

Contribuições ao estudo de modelagem de equações estruturais na avaliação da satisfação do cliente de serviços de comunicações móveis

No mercado de telecomunicações as transformações tecnológicas das últimas décadas aliaram-se a um cenário formado por empresas de alta tecnologia que caracterizam o setor de comunicações móveis pessoais em todo mundo. Neste contexto, as empresas deste setor preocupam-se cada vez mais com a competitividade, oferta de serviços, área de atendimento, demanda reprimida e a lealdade do cliente. Estudos de comportamento do consumidor pesquisam a satisfação e lealdade de clientes como fatores básicos para relações bem sucedidas e duradouras com as empresas. A complexidade das relações entre variáveis na avaliação da satisfação do cliente em comunicações móveis pode ser adequadamente pesquisada com a utilização de métodos estatísticos multivariados. Essa tese analisou as relações causais envolvendo os antecedentes e consequentes associados à satisfação do cliente, no segmento de comunicações móveis, bem como desenvolveu e validou um modelo comportamental do cliente no uso deste serviço, buscando explicar as relações entre os construtos envolvidos: satisfação, qualidade dos serviços, valor percebido, imagem da marca, lealdade e reclamação. Foi estabelecida uma ampla base teórica para avaliar a importância estratégica do modelo que relaciona a influência na satisfação do serviço com as percepções dos clientes e avaliada a precisão deste modelo, por meio de uma análise comparativa a utilização de três métodos de estimação dos seus parâmetros, MLE, GLS, e ULS, com o emprego de modelagem de equações estruturais. Foram feitas aplicações em análises de dados, sendo testada e avaliada empiricamente, a influência do gênero na satisfação do cliente deste setor, além de uma segmentação de mercado utilizando mapas auto-organizáveis e a correspondente validação deste processo, com modelagem de equações estruturais.Os resultados do estudo empírico produziram uma boa qualidade de ajustamento para o modelo teórico proposto, com evidências do estabelecimento de uma adequada capacidade explicativa e preditiva, destacando-se a relevância da relação causal entre a satisfação e lealdade, em consonância com diversos estudos realizados para os mercados de comunicações móveis.

Processamento Inteligente de Sinais de Pressão e Temperatura Adquiridos Através de Sensores Permanentes em Poços de Petróleo

Originally aimed at operational objectives, the continuous measurement of well bottomhole pressure and temperature, recorded by permanent downhole gauges (PDG), finds vast applicability in reservoir management. It contributes for the monitoring of well performance and makes it possible to estimate reservoir parameters on the long term. However, notwithstanding its unquestionable value, data from PDG is characterized by a large noise content. Moreover, the presence of outliers within valid signal measurements seems to be a major problem as well. In this work, the initial treatment of PDG signals is addressed, based on curve smoothing, self-organizing maps and the discrete wavelet transform. Additionally, a system based on the coupling of fuzzy clustering with feed-forward neural networks is proposed for transient detection. The obtained results were considered quite satisfactory for offshore wells and matched real requisites for utilization

Auto-eficácia de alunos de administração: um estudo com concluintes do curso de graduação em Administração no Estado do Pará

The current study presents the characteristics of self-efficacy of students of Administration course, who work and do not work. The study was conducted through a field research, descriptive, addressed quantitatively using statistical procedures. Was studied a population composed of 394 students distributed in three Higher Education Institutions, in the metropolitan region of Belém, in the State of Pará. The sampling was not probabilistic by accessibility, with a sample of 254 subjects. The instrument for data collection was a questionnaire composed of a set of questions divided into three sections: the first related to sociodemographic data, the second section was built to identify the work situation of the respondent and the third section was built with issues related to General Perceived Self-Efficacy Scale proposed by Schwarzer and Jerusalem (1999). Sociodemographic data were processed using methods of descriptive statistics. This procedure allowed characterizing the subjects of the sample. To identify the work situation, the analysis of frequency and percentage was used, which allowed to classify in percentage, the respondents who worked and those that did not work, and the data related to the scale of self-efficacy were processed quantitatively by the method of multivariate statistics using the software of program Statistical Package for Social Sciences for Windows - SPSS, version 17 from the process of Exploratory Factor Analysis. This procedure allowed characterizing the students who worked and the students who did not worked. The results were discussed based on Social Cognitive Theory from the construct of self-efficacy of Albert Bandura (1977). The study results showed a young sample, composed the majority of single women with work experience, and indicated that the characteristics of self-efficacy of students who work and students who do not work are different. The self-efficacy beliefs of students who do not work are based on psychological expectations, whereas the students who work demonstrated that their efficacy beliefs are sustained by previous experiences. A student who does not work proved to be reliant in their abilities to achieve a successful performance in their activities, believing it to be easy to achieve your goals and to face difficult situations at work, simply by invest a necessary effort and trust in their abilities. One who has experience working proved to be reliant in their abilities to conduct courses of action, although know that it is not easy to achieve your goals, and in unexpected situations showed its ability to solve difficult problems

Condomínios fechados: a produção habitacional contemporânea e a auto-exclusão dos ricos no espaço urbano de Natal RN (1995 2003)

The present work analyzes the fast evolution of gated communities in Natal-RN´s urban space. Characterized by the occupation of large areas, providing private security and utilities, this kind of real estate use arises a long list of questions and issues from society and scholars, due to privatization of urban space, bending of law constraints and the lack of an integrated planning of the cities where they are built. The reasons for its fast growth in Brazil s urban areas are analyzed, considering the impact on formal urban planning and municipal services and on the identification of urbanistic, architectural pattern and constraints, as well as legal, social and economic issues. This study is based on the detailed analysis of the first three units of gated communities built in the urban space in Natal, between 1995 and 2003, including their evolution throughout time and the specific social and economic reasons for its present widespread adoption in Brazilian real estate market and, particulary, in our city. The main objective of this piece of work is to answer the why s and how s these phenomena evolved, setting a basis for the definition of adequate public policies and regulation of this kind of urban land use

Projeto, construção e análise de um prototipo vibracional em escala de bancada aplicável ao tratamento de água de produção de petróleo bruto, mediante inovadora operação híbrida de adsorção e auto-flotação

A self-flotator vibrational prototype electromechanical drive for treatment of oil and water emulsion or like emulsion is presented and evaluated. Oil production and refining to obtain derivatives is carried out under arrangements technically referred to as on-shore and off-shore, ie, on the continent and in the sea. In Brazil 80 % of the petroleum production is taken at sea and area of deployment and it cost scale are worrisome. It is associated, oily water production on a large scale, carrier 95% of the potential pollutant of activity whose final destination is the environment medium, terrestrial or maritime. Although diversified set of techniques and water treatment systems are in use or research, we propose an innovative system that operates in a sustainable way without chemical additives, for the good of the ecosystem. Labyrinth adsor-bent is used in metal spirals, and laboratory scale flow. Equipment and process patents are claimed. Treatments were performed at different flow rates and bands often monitored with control systems, some built, other bought for this purpose. Measurements of the levels of oil and grease (OGC) of efluents treaty remained within the range of legal framework under test conditions. Adsorbents were weighed before and after treatment for obtaining oil impregna-tion, the performance goal of vibratory action and treatment as a whole. Treatment technolo-gies in course are referenced, to compare performance, qualitatively and quantitatively. The vibration energy consumption is faced with and without conventional flotation and self-flotation. There are good prospects for the proposed, especially in reducing the residence time, by capillary action system. The impregnation dimensionless parameter was created and confronted with consecrated dimensionless parameters, on the vibrational version, such as Weber number and Froude number in quadratic form, referred to as vibrational criticality. Re-sults suggest limits to the vibration intensity

O outro diálogo: uma compreensão do diálogo interno

This thesis aims to enable a wider comprehension on thought operation as well as suggest alternatives for the formation of reflexive, critical, autonomous and creative individuals. The research defends the idea that it is possible for an individual to develop vigilant attention that makes thought flexibilization and change in the course of action, possible. This operation is called Internal Dialogue and is essentially characterized by a continuous openness towards novelty and learning. This makes it possible to minimize the usual way thought operates, in a automatic fashion (automatism). The research was based on theoretical references and ideas of David Bohm (1989;1994;2005) and Michael Polanyi (1983). The main emphasis was the understanding that a crisis situation enables awareness and state of alert that favors a more flexible thought pattern (Aragão Gomes, 1994, 1997). The methodology used was presentation and analysis of these moments through autobibliographical records with indication of crisis on behalf of the subjects. Other criteria were also used that enabled the composition of the analyzed material such as the fact that: the subjects were public and real, the data was available through accessible material; the subjects identified themselves as in crisis; these crisis were of varied kinds; they had different social, cultural and professional profiles. Thus, three auto-bibliographical elements were selected: the Infidel: the story of a woman that challenged Islam (2007), written by the political Muslim author Ayaan Hirsi; Still me: memories (2001), of the actor Christopher Reeve as well as Confessions of a Philosopher (2001), by the philosopher Bryan Magee. In these books an analysis was made related to parts that stated action an though operation that express internal dialogue. These were organized into categories that were pointed out as relevant for the identification of internal dialogue such as: Perceptions of physical reaction; emotions, beliefs and issues, individual actions, self judgment and thought, self questioning, comprehension, observation and empirical investigation, perception of the changes they performed in the world, escape of conditioning as well as action that resulted in new meaning. The analysis performed reinforces our goal once it sated that internal dialogue is an important tool that allows thought awareness, minimizing common automatism and making consciousness possible as well as favoring the occurrence of critical and reflexive thought. Thus, final considerations deal with the need for the development of teaching methodologies that address internal dialogue as a counterpoint to the many daily action that reinforce the automatism of thought

Outro diálogo: uma compreensão do diálogo interno

This thesis aims to enable a wider comprehension on thought operation as well as suggest alternatives for the formation of reflexive, critical, autonomous and creative individuals. The research defends the idea that it is possible for an individual to develop vigilant attention that makes thought flexibilization and change in the course of action, possible. This operation is called Internal Dialogue and is essentially characterized by a continuous openness towards novelty and learning. This makes it possible to minimize the usual way thought operates, in a automatic fashion (automatism). The research was based on theoretical references and ideas of David Bohm (1989;1994;2005) and Michael Polanyi (1983). The main emphasis was the understanding that a crisis situation enables awareness and state of alert that favors a more flexible thought pattern (Aragão Gomes, 1994, 1997). The methodology used was presentation and analysis of these moments through autobibliographical records with indication of crisis on behalf of the subjects. Other criteria were also used that enabled the composition of the analyzed material such as the fact that: the subjects were public and real, the data was available through accessible material; the subjects identified themselves as in crisis; these crisis were of varied kinds; they had different social, cultural and professional profiles. Thus, three auto-bibliographical elements were selected: the Infidel: the story of a woman that challenged Islam (2007), written by the political Muslim author Ayaan Hirsi; Still me: memories (2001), of the actor Christopher Reeve as well as Confessions of a Philosopher (2001), by the philosopher Bryan Magee. In these books an analysis was made related to parts that stated action an though operation that express internal dialogue. These were organized into categories that were pointed out as relevant for the identification of internal dialogue such as: Perceptions of physical reaction; emotions, beliefs and issues, individual actions, self judgment and thought, self questioning, comprehension, observation and empirical investigation, perception of the changes they performed in the world, escape of conditioning as well as action that resulted in new meaning. The analysis performed reinforces our goal once it sated that internal dialogue is an important tool that allows thought awareness, minimizing common automatism and making consciousness possible as well as favoring the occurrence of critical and reflexive thought. Thus, final considerations deal with the need for the development of teaching methodologies that address internal dialogue as a counterpoint to the many daily action that reinforce the automatism of thought

Globos e mapas ao alcance das mãos : ensino de matemática numa perspectiva de alfabetização funcional na EJA

The following dissertation has as its main advantage the privilege of visualizing the literacy processes through the angle of the functional perspective, which does not see the literary process as a practice solely based on the decoding of alphabetical codes, and then allows for the opening of ample spaces for the allocation of mathematical skills in the realms of the functional literacy. The main object of this study was to investigate which are the contributions that a sequence of activities and of methodologies developed for the teaching of Geometry could provide for a part of the functional literacy process in mathematics of youngsters and adults of EJA, corresponding to the acquisition or to the improvement of skills related to the orientation capacity. The focus of the analyses consisted in the practice of these activities with the young and adult students of an EJA class belonging to a municipal public school of Natal/RN. The legacies of Paulo Freire about the redimensioning of the role of the teacher, of the students, of the knowledge and of their connections within the teaching-learning process, prevailed in the actions of the methodology implemented in the classroom and, especially, in the establishing of dialogic connections with the students, which directed all the observations and analyses regarding the collected information. The results indicated that the composition of articulations between the teaching of mathematics and the exploration of maps and the earth globe enabled the creation of multidisciplinary learning environments and situations, where we could observe, gradually, the development of procedures and attitudes indicating the evolution of space-visual type skills

Os ateliês (auto)formativos na constituição do sujeito docente da educação matemática

The object of study of this thesis is the use of (self)training workshops as a fundamental process for the constitution of the teaching subject in mathematics education. The central purposes of the study were to describe and analyze a learning process of mathematics teachers supported by the training-research methodology, which procedures have been affected with the practice of (self)training workshops as a way of collaborating to the constitution of the teaching subject in Mathematics Education. The survey was conducted with a group of teachers in the city of Nova Cruz, Rio Grande do Norte through a process of continued education realized in the training workshops having as main goal the realization of the group s (self)training sessions in order to lead participants to the extent of their autonomy in their personal and professional transformations. The results obtained in the formative processes have shown the need to develop activities of mathematics teaching as a contribution to overcome the conceptual difficulties of the teachers, apart from their (self)reflections about themselves and the educational processes in which they belong. The results raised some propositions about (self)training workshops that may be incurred in practices to be included in the curriculum frameworks or materialize as a strategy of pedagogical work in training courses for teachers of mathematics. Also, they can constitute an administrative and educational activity to be instituted in the public schools of Basic Education

A auto formação maternal: cenários de uma educação vivencial humanescente

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Corporeidade e formação docente: cenário geográfico das histórias de vida

L étude vient de présenter la recherche qui a eu lieu pendent la formation des professeurs d l'Institut d'Enseignement Supérieur Président Kennedy à Natal-RN, dont les sujets son les professeurs de la septième période du Cours Normal Supérieur. L objet d´étude sont les pratiques formatives de ces professeurs en formation par des difficultés qui ils présentaient pour comprendre les relations entre les domaines de connaissance le l interface avec les expériences, et le processus de formation. L objectif a éte identifier dans l expériences ludopoèthiques, les lieus de construction de l autoterritorialité des professeus en tant qu en formation. Parmi les pressuposés théoriques qui ont soutenu le développement de la recherche comprennent: Enseignement Humain ; Corps-espace; Corporéité; Auto-formation et Transdisciplinarité. L'approche de la recherche qualitative adopte les principes de la rechercheaction- formation, dans une perspective etnophenomenologique. La discipline Memorial de Formação avec l'utilisation de jeu de sable,a été le laboratoire des expériences, l outil de la recherche qui a subventionné la construction des narratives autobiographiques. La perspective transdisciplinaire sur l'étude a rassemblé dans la dimension épistémologique les références théoriques de la Géographie, de la corporéité. et des histoires de vie dans la formation. L'Atelier Corps (Bio) Géographique a été développé par cinq rencontres: Paysage du Sensible, Lieu de Sentipensar, Territoires des Découvertes, Région des Savoirs et de l'Espace Géographique de la Ecoformação. Les expériences vécues dans l'Atelier par les participants de la recherche ont permis une sensible et attentive écoute sur leur propre histoire, en donnant la possibilité de la reconstruction de la mémoire, et en faisant réfléchir sur son l'auto-formation. La découverte des cartes et la construction d un nouveau paysage autoformatif par les memoires ludiques des différentes phases de la vie, a fait apparaître la propriété ludopoètique de l autoterriotalité, au même temps qui a enrégistré la construction ontologique dans sa corporéité