Made available in DSpace on 2016-04-29T13:17:49Z (GMT). No. of bitstreams: 1 Laura Muniz Rocha.pdf: 1241168 bytes, checksum: eaaf1dca965f9aa61ee39990e47879dd (MD5) Previous issue date: 2013-06-21 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Chronic Mild Stress (CMS) is an experimental animal model of induced anhedonia by exposing rats to a protocol of mild stressors for a long period of time. This model is an attempt to reproduce in controlled environment conditions analogous to the real environment, seen as important to produce behavioral changes. To identify other effects of exposure to CMS, this study aimed to verify whether the exposure to chronic mild stress produces changes in the establishment of a simple discrimination after the expouse to the protocol. Therefore, the subjects of this study had their weight and food and water intake measured daily, tests of consumption and preference of liquid were realized weekly; subjects were exposed to the protocol stressors over six weeks and, after this period was initiated the discriminative training. The experiment consisted of four experimental conditions: (1) one subject was exposed, like all other subjects, to tests of consumption and preference of liquids, (2) four subjects were exposed to the protocol, (3) four subjects were exposed to the protocol and to a discrimination procedure(4) four subjects were exposed only to the discrimination procedure and they weren t exposoused to the chronic mild stress. The results obtained in this study indicate that: (a) subjects exposed to the protocol showed a greater loss and variation of the body weight; (b) during the protocol the average of water consumption increased and average food consumption decreased for subjects exposed to the protocol. (c) tests of consumption and preference of liquids did not show a reduction in preference for the sucrose subtance but an increase in the total fluid intake for subjects exposed to stress. And, finally, (d) observed that exposure protocol stressors interfere with the acquisition of a simple discrimination. For subjects exposed to the protocol were required, on average, twice as many sessions to reach the criterion of two consecutive sessions with discriminative indices above 80%. and (e) that the subjects exposed to the protocol showed differences in tests of generalization when compared with subjects exposed only to discrimination. And, lastly (d) observed that exposure to the protocol interfered the acquisition of a simple discrimination. The subjects exposed to the protocol required, on average, twice as many sessions to reach the criterion of two consecutive sessions with discriminative indices above 80% and (e) the subjects exposed to the protocol showed differences in the generalization tests when compared with subjects exposed only to discrimination.Thereby, the exposure to a condition of chronic mild stress and affects the acquisition of a simple discrimination established after the protocol. This result may indicate that exposure to stress condition altered the reinforcing value of the stimulus for the subjects who were exposed to it, this change may have been responsible for the differences obtained in the discrimination of subjects exposed to this condition and subjects who were not exposed to the protocol / O Chronic Mils Stress (CMS) é um modelo animal experimental de anedonia induzida através da exposição de ratos a um protocolo de estressores crônicos e moderados por um longo período de tempo. Este modelo é uma tentativa de reproduzir, em ambiente controlado, condições análogas às do ambiente real, vistas como importantes para a produção de alterações comportamentais. Visando identificar outros efeitos da exposição ao CMS, o presente estudo teve como objetivo verificar se a exposição a eventos aversivos crônicos e moderados produz alterações no estabelecimento de uma discriminação simples posterior ao protocolo de estressores. Para tanto, os sujeitos do presente estudo tiveram o peso e o consumo de ração aferidos diariamente; foram expostos a testes semanais de consumo e preferência de líquidos; foram expostos ao protocolo de estressores ao longo de seis semanas e, após o encerramento deste, foi iniciado o treino discriminativo. O delineamento foi composto por quatro condições experimentais: (1) um sujeito foi exposto, como todos os outros sujeitos, aos testes de consumo e preferência de líquidos, (2) quatro sujeitos foram expostos ao protocolo de estressores, (3) quatro sujeitos foram expostos ao protocolo de estressores e a discriminação simples e (4) quatro sujeitos foram expostos a uma discriminação simples sem exposição aos estímulos crônicos e moderados. Os resultados obtidos no presente estudo indicam que: (a)os sujeitos expostos ao protocolo de estressores apresentaram uma maior perda e variação no peso corporal; (b) durante o protocolo o consumo médio de água aumentou e o consumo médio de ração diminuiu para os sujeitos expostos ao protocolo. (c) nos testes de consumo e preferência de líquidos não foi observado uma redução na preferência por sacarose e sim um aumento no consumo total de líquidos para os sujeitos expostos a condição de estresse. E, por fim, (d) observou-se que a exposição ao protocolo de estressores interferiu na aquisição de uma discriminação simples. Para os sujeitos expostos ao protocolo foram necessárias, em média, o dobro de sessões para atingir o critério de duas sessões consecutivas com índices discriminativos superiores a 80% e (e) que os sujeitos expostos ao protocolo apresentaram diferenças nos testes de generalização se comparados com os sujeitos expostos somente à discriminação. Assim, é possível concluir que a exposição a uma condição de estresse crônica e moderada afeta a aquisição de uma discriminação simples posteriormente estabelecida. Esse resultado pode indicar que a exposição à condição de estresse alterou o valor reforçador do estímulo para os sujeitos que foram expostos a ele, essa alteração pode ter sido responsável pelas diferenças obtidas na discriminação dos sujeitos expostos a essa condição e dos sujeitos que não foram expostos aos estressores

Made available in DSpace on 2016-04-27T16:57:25Z (GMT). No. of bitstreams: 1 Fernanda Fuentes Azambuja.pdf: 2505770 bytes, checksum: 3bbdb5dea1fcb8bf7c8f1f8044d16c66 (MD5) Previous issue date: 2013-05-22 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The student s difficulty in High School with the polynomial is famous, specially, about divisibility. Such fact instigated determining, with the purpose of research hereby presented: investigating the effect of the retaking of the divisibility of the natural numbers with a student from High School and its comprehension about polynomial divisibility. An empirical research was held, of qualitative focus, more specifically a study of ethnographical case, according to André (2005), in which the calculator was used not only as a motivating tool for the retaking, but also as a tool for data survey. The analyses were based, mainly, in basic elements of the theory APOS (Dubinsky and MCDonald, 2001). It was concluded that, although subjects have done the correlation between the algorithms of divisibility of natural numbers and of polynomials, and the fake conception of polynomial constructed by them that identified a polynomial as a number that undermined the possibility of the intended analogy. As for the use of the calculator, it was concluded that it was the tool that helped the subjects not to deviate of the focus of the proposed activities, helping them to recover the conceptions of divisibility of the natural numbers / A dificuldade do estudante do Ensino Médio com o conteúdo de Polinômios é notória, em especial, sobre a divisibilidade. Tal fato instigou determinar, como objetivo da pesquisa aqui apresentada: investigar o efeito da retomada da divisibilidade dos números naturais com estudante do Ensino Médio em sua compreensão sobre a divisibilidade de polinômios. Realizou-se uma pesquisa empírica, de cunho qualitativo, mais especificamente um estudo de caso etnográfico, conforme André (2005), na qual a calculadora foi utilizada não só como um instrumento motivador para a retomada, como também como instrumento de coleta de dados. As análises embasaram-se, sobretudo, em elementos básicos da teoria APOS (Dubinsky e MCDonald, 2001). Concluiu-se que, embora os sujeitos tenham feito a correlação entre os algoritmos da divisibilidade dos números naturais e dos polinômios, a falsa concepção de polinômio construída por eles que identificavam um polinômio como um número solapou a possibilidade da analogia pretendida. Quanto ao uso da calculadora, concluiu-se que ela foi um instrumento que auxiliou os sujeitos a não se desviarem do foco das atividades propostas, auxiliando-os a resgatar as concepções de divisibilidade dos números naturais

Perceptrons são redes neurais sem retroalimentação onde os neurônios estão dispostos em camadas. O perceptron considerado neste trabalho consiste de uma camada de N neurônios sensores Si = ±1; i = 1, , N ligados a um neurônio motor δ através das conexões sinápticas (pesos) Wi; i = 1, ..., N cujos valores restringimos a ±1. Utilizando o formalismo de Mecânica Estatística desenvolvido por Gardner (1988), estudamos os efeitos de eliminarmos uma fração de conexões sinápticas (diluição ) nas capacidades de memorização e generalização da rede neural descrita acima. Consideramos também o efeito de ruído atuando durante o estágio de treinamento do perceptron. Consideramos dois tipos de diluição: diluição móvel na qual os pesos são cortados de maneira a minimizar o erro de treinamento e diluição fixa na qual os pesos são cortados aleatoriamente. A diluição móvel, que modela lesões em cérebro de pacientes muito jovens, pode melhorar a capacidade de memorização e, no caso da rede ser treinada com ruído, também pode melhorar a capacidade de generalização. Por outro lado, a diluição fixa, que modela lesões em cérebros de pacientes adultos, sempre degrada o desempenho da rede, sendo seu principal efeito introduzir um ruído efetivo nos exemplos de treinamento. / Perceptrons are layered, feed-forward neural networks. In this work we consider a per-ceptron composed of one input layer with N sensor neurons Si = ±1; i = 1, ... , N which are connected to a single motor neuron δ through the synaptic weights Wj; i = 1, ... , N, which are constrained to take on the values ±1 only. Using the Statistical Mechanics formalism developed by Gardner (1988), we study the effects of eliminating a fraction of synaptic weights on the memorization and generalization capabilities of the neural network described above. We consider also the effects of noise acting during the perceptron training stage. We consider two types of dilution: annealed dilution, where the weights are cut so as to minimize the training error and quenched dilution, where the weights are cut randomly. The annealed dilution which models brain damage in very young patients can improve the memorization ability and, in the case of training with noise, it can also improve the generalization ability. On the other hand, the quenched dilution which models lesions on adult brains always degrades the performance of the network, its main effect being to introduce an effective noise in the training examples.

La recherche de points communs entre des descriptions de données ou de connaissances est un problème de raisonnement fondamental en Machine Learning, qui a été formalisé par G. Plotkin dans les années 70s sous la forme du calcul du plus petit généralisant de ces descriptions. L'identification des plus petits généralisants a un large panel d'applications qui vont de l'optimisation de requêtes (e.g., pour matérialiser les points communs entre des requêtes lors de la sélection de vues ou pour factoriser leur exécution dans un contexte d'accès concurrentiel), à la recommandation dans le contexte des réseaux sociaux (e.g. pour créer de liens entre des utilisateurs basées sur leurs points communs selon leur profil ou leurs recherches). Dans cette thèse nous avons revisité la notion du plus petit généralisant dans le contexte de Resource Description Framework (RDF) et le fragment conjonctif de son langage de requêtes associé SPARQL, alias Basic Graph Pattern (BGP) queries. Contrairement à l'état de l'art, nous ne considérons aucune restriction, ni structurelle ni sémantique, sur les graphes et les requêtes. Nos contributions incluent la définition et le calcul des plus petits généralisants dans ces deux formalismes ce qui revient à trouver le plus grand ensemble de points communs entre des bases de données incomplètes et des requêtes conjonctives en présence de contraintes déductives. Nous proposons également une évaluation expérimentale de nos contributions. / Finding commonalities between descriptions of data or knowledge is a fundamental task in Machine Learning. The formal notion characterizing precisely such commonalities is known as least general generalization of descriptions and was introduced by G. Plotkin in the early 70's, in First Order Logic. Identifying least general generalizations has a large scope of database applications ranging from query optimization (e.g., to share commonalities between queries in view selection or multi-query optimization), to recommendation in social networks (e.g., to establish connections between users based on their commonalities between proles or searches), through exploration (e.g., to classify/categorize datasets and to identify common social graph patterns between organizations (e.g., criminal ones)). In this thesis we revisit the notion of least general generalizations in the entire Resource Description Framework (RDF) and popular conjunctive fragment of SPARQL, a.k.a. Basic Graph Pattern (BGP) queries. By contrast to the literature, we do not restrict the structure nor semantics of RDF graphs and BGPQs. Our contributions include the denition and the computation of least general generalizations in these two settings, which amounts to nding the largest set of commonalities between incomplete databases and conjunctive queries, under deductive constraints. We also provide an experimental assessment of our technical contributions.

Perceptrons são redes neurais sem retroalimentação cujos os neurônios estão dispostos em camadas. O perceptron considerado neste trabalho consiste de uma camada de N neurônios sensores Si = 1; i = 1,.... N ligados a um único neurônio motor através das conexões sinápticas , Ji; i = 1, .... N. Utilizando o formalismo da Mecânica Estatística desenvolvido por Gardner e colaboradores, estudamos os efeitos da eliminação de uma fração dos pesos sinápticos (diluição) nas capacidades de aprendizado e generalização de dois tipos de perceptrons, a saber, o perceptron linear e o perceptron Booleano. No perceptron linear comparamos o desempenho de redes lesadas por diferentes tipos de diluição, que podem ocorrer durante ou após o processo de aprendizado. Essa comparação mostra que a estratégia de minimizar o erro de treinamento, não fornece o menor erro de generalização, além do que, dependendo do tamanho do conjunto de treinamento e do nível de ruído, os pesos menores podem se tornar os fatores mais importantes para o bom funcionamento da rede. No perceptron Booleano investigamos apenas o efeito da diluição após o término do aprendizado na capacidade de generalização da rede neural treinada com padrões ruidosos. Neste caso, apresentamos uma comparação entre os desempenhos relativos de cinco regras de aprendizado: regra de Hebb, pseudo-inversa, algoritmo de Gibbs, algoritmo de estabilidade ótima e algoritmo de Bayes. Em particular mostramos que a diluição sempre degrada o desempenho de generalização e o algoritmo de Bayes sempre fornece o menor erro de generalização. / Perceptrons are layered, feed-forward neural networks. In this work we consider a perceptron composed of one input layer with N sensor neurons Si = 1; i = 1,..., N which are connected to a single motor neuron a through the synaptic weights Ji; i = 1,..., N. Using the Statistical Mechanics formalism developed by Gardner and co-workers, we study the effects of eliminating a fraction of synaptic weights (dilution) on the learning and generalization capabilities of the two types of perceptrons, namely, the linear perceptron and the Boolean perceptron. In the linear perceptron we compare the performances of networks damaged by different types of dilution, which may occur either during or after the learning stage. The comparison between the effects of the different types of dilution, shows that the strategy of minimizing the training error does not yield the best generalization performance. Moreover, this comparison also shows that, depending on the size of the training set and on the level of noise corrupting the training data, the smaller weights may became the determinant factors in the good functioning of the network. In the Boolean perceptron we investigate the effect of dilution after learning on the generalization ability when this network is trained with noise examples. We present a thorough comparison between the relative performances of five learning rules or algorithms: the Hebb rule, the pseudo-inverse rule, the Gibbs algorithm, the optimal stability algorithm and the Bayes algorithm. In particular, we show that the effect of dilution is always deleterious, and that the Bayes algorithm always gives the lest generalization performance.

Dentre as técnicas de mineração de dados encontra-se a associação, a qual identifica todas as associações intrínsecas contidas na base de dados. Entretanto, essa característica, vantajosa por um lado, faz com que um grande número de padrões seja gerado, sendo que muito deles, mesmo sendo estatisticamente aceitos, são triviais, falsos, ou irrelevantes à aplicação. Além disso, a técnica de associação tradicional gera padrões compostos apenas por itens contidos na base de dados, o que leva à extração, em geral, de um conhecimento muito específico. Essa especificidade dificulta a obtenção de uma visão geral do domínio pelos usuários finais, que visam a utilização/exploração de conhecimentos úteis e compreensíveis. Assim, o pós-processamento das regras descobertas se torna um importante tópico, uma vez que há a necessidade de se validar as regras obtidas. Diante do exposto, este trabalho apresenta uma abordagem de pós-processamento de regras de associação que utiliza conhecimento de domínio, expresso via taxonomias, para obter um conjunto de regras de associação generalizadas compacto e representativo. Além disso, a fim de avaliar a representatividade de padrões generalizados, é apresentado também neste trabalho um estudo referente à utilização de medidas de interesse objetivas quando aplicadas a regras de associação generalizadas. Nesse estudo, a semântica da generalização é levada em consideração, já que cada uma delas fornece uma visão distinta do domínio. Como resultados desta tese, foi possível observar que: um conjunto de regras de associação pode ser compactado na presença de um conjunto de taxonomias; para cada uma das semânticas de generalização existe um conjunto de medidas mais apropriado para ser utilizado na avaliação de regras generalizadas / The association technique, one of the data mining techniques, identifies all the intrinsic associations in database. This characteristic, which can be advantageous on the one hand, generates a large number of patterns. Many of these patterns, even statistically accepted, are trivial, spurious, or irrelevant to the application. In addition, the association technique generates patterns composed only by items in database, which in general implies a very specific knowledge. This specificity makes it difficult to obtain a general view of the domain by the final users, who aims the utilization/exploration of useful and comprehensible knowledge . Thus, the post-processing of the discovered rules becomes an important topic, since it is necessary to validate the obtained rules. In this context, this work presents an approach for post-processing association rules that uses domain knowledge, expressed by taxonomies, to obtain a reduced and representative generalized association rule set. In addition, in order to evaluate the representativeness of generalized patterns, a study referent to the use of objective interest measures when applied to generalized association rules is presented. In this study, the generalization semantics is considered, since each semantic provides a distinct view of the domain. As results of this thesis, it was possible to observe that: an association rule set can be compacted with a taxonomy set; for each generalization semantic there is a measure set that is more appropriate to be used in the generalized rules evaluation

The ability of direct care staff members to carry out behavior programs, specific protocols written by a behavior analyst, or recommendations made after completion of a functional behavioral assessment is an essential tool needed for such documents to actually be meaningful to patients. Since direct care staff members spend the most time directly working with patients, it is imperative that they carry out intervention procedures with reliability and fidelity. This study evaluated the effectiveness of staff training procedures as well as organizational behavior management techniques used to ensure that staff members are equipped with the tools they need and are properly motivated to carry out the proposed intervention procedures. Staff members received training on the Tools for Positive Behavior Change curriculum developed by the Behavior Analysis Services Program at the University of South Florida using a myriad of training techniques. Then, organizational behavior management techniques were implemented in order to maintain tool implementation and positive interactions with patients over time. Effectiveness of these procedures was measured using a concurrent multiple baseline across participant research design. Results showed that participants did not increase, or only slightly increased, tool use and positive interactions after being trained. However, tool use and positive interactions showed a more substantial increase for most participants after the implementation of organizational behavior management procedures.

Simplification of buildings based on typification Abstract The diploma thesis is focused on cartographic generalization. Its main aim was to develop a new method of simplification of buildings based on typification for areas with lower density of buildings (rural or mountain areas). The proposed method was designed for large scale maps (1 : 25 000 and 1 : 50 000). The presented generalization algorithm is based on preferential selection of buildings to be drawn on the map according to their civic importance, area and location towards roads, railways and streams. It respects cartographic rules used for this type of generalization. The algorithm was implemented in the Python programming language using the Shapely and Fiona libraries for a purpose of its proper testing. The ZABAGED and DATA50 data were chosen as suitable test data. Among other things, this thesis also introduces the evaluation method of typification results, which uses Voronoi diagram. Achieved results are presented on maps of fifteen villages with different spatial structure in both targeted scales. Keywords: digital cartography, generalization, typification, building, simplification

This paper deals with generalization fo Gershgorin's theorem. This theorem is investigated and generalized in terms of contour integrals, directed graphs, convex analysis, and clock matrices. These results are shown to apply to some specified matrices such as stable and stochastic matrices and some examples will show the relationship of eigenvalue inclusion regions among them.

This study examined, within a multiple baseline design, the development of generalized imitative repertoires and the occurrence of contingency testing in children with autism. Generalized imitation refers to an imitative response class maintained by a conditioned reinforcer: similarity. In the case of imitation, a response class is established by reinforcement of sufficient exemplars of different imitations; the results is a general repertoire of imitating novel responses on their first presentation. Generalized imitation was facilitated through reinforcement procedures involving shaping and fading. Multiple experimenters and multiple settings have been involved to promote the generalization of imitation. Contingency testing, which has been noticed to naturally occur in typically developing children when imitated, was targeted in the examined treatment, by employing a procedure where the experimenter imitated the child. It was hypothesized that the imitation training leads to generalized imitation and that the imitation of the child by the therapist leads to the occurrence of contingency testing. The results of the study show that the shaping and reinforcement procedures determined an increase in participants' trained imitative responding but no corresponding increase in novel, probed imitative responses. The data indicate the emergence of an imitative repertoire in need of further training. Additionally, the results suggest that generalization of skills across therapists and settings has occurred. Imitation of the child by the therapist had been employed for a very small number of sessions. Notwithstanding, the results yielded an increase in the contingency testing behaviors for both participants.