análise experimental do efeito da diversificação em carteiras de ações: a relação entre risco e quantidade de ativos sob a ótica da estratégia ingênua

The objective is to analyze the relationship between risk and number of stocks of a portfolio for an individual investor when stocks are chosen by "naive strategy". For this, we carried out an experiment in which individuals select actions to reproduce this relationship. 126 participants were informed that the risk of first choice would be an asset average of all standard deviations of the portfolios consist of a single asset, and the same procedure should be used for portfolios composed of two, three and so on, up to 30 actions . They selected the assets they want in their portfolios without the support of a financial analysis. For comparison we also tested a hypothetical simulation of 126 investors who selected shares the same universe, through a random number generator. Thus, each real participant is compensated for random hypothetical investor facing the same opportunity. Patterns were observed in the portfolios of individual participants, characterizing the curves for the components of the samples. Because these groupings are somewhat arbitrary, it was used a more objective measure of behavior: a simple linear regression for each participant, in order to predict the variance of the portfolio depending on the number of assets. In addition, we conducted a pooled regression on all observations by analyzing cross-section. The result of pattern occurs on average but not for most individuals, many of which effectively "de-diversify" when adding seemingly random bonds. Furthermore, the results are slightly worse using a random number generator. This finding challenges the belief that only a small number of titles is necessary for diversification and shows that there is only applicable to a large sample. The implications are important since many individual investors holding few stocks in their portfolios

A travessia do trágico no romance d A Pedra do Reino de Ariano Suassuna

The present work seeks to investigate and discuss about the Greek Tragedy s elements at Ariano Suassuna s romance called τ Romance d A Pedra do Reino e o Principe do Sangue do Vai e Volta, connecting it directly to mythic, epic, poetic, and romances aspects at his work. The romance has as the protagonist the backcountry Pedro Dinis Quaderna. Quaderna is a character which is simultaneously popular, elitist, enigmatic, naive, and an intellectual man that has a great erudition. Quaderna is a character that seeks, by using the Literature, to reestablish a Brazilian backcountry kingdom which he s supposedly the king, always trying to empathizes the Brazilian northeast region like if it was a nation apart. By impressing a national personality to the Brazilian northeast , Quaderna tries to become an epic poet just like Homer, denoting a strong influence of the Epopee. Quaderna, just like many characters of Greek Tragedy, has at his family past time a lot of tragic circumstances. These facts that ocurred to his relativos like the your uncle Pedro Sebastião Garcia Barreto s death, the disappearement of his cousin Sinésio, and the contest between the brothers Arésio and Sinésio, and others aspects, remind us remarkable influences, beyond the Epopee, of the Greek Tragedy. By reading the romance we may notice many similarities between Quaderna s trajectory and Greek Tragedy heroes. To make an analysis about the tragic aspects at Suassuna s work, we need to dialogue with many theoreticals that have written about the tragic and comparate with many parts of Suassuna s with classics character s texts of Greek Tragedy. At the following chapters we seek to provide romance s elementaries notions, as well as tragic notions, the dialogue with mythics aspects and the tragic and epic aplicability at Suassuna s work

A ação do coordenador pedagógico e as suas contribuições a vivência compreensiva sob a perspectiva conscienciológica

This work is based on a reflection about my personal and professional background as a teacher and a pedagogical supervisor in two public schools in the municipality of Natal, RN, and how relevant this background is to the development of a proposal of continued formation within the scope of the school, in which a diversity of actionreflection strategies are present. In such contexts, I have identified several of my personality traits as being likely advantages or disadvantages that may contribute or not to the coming up of misunderstanding situations. The self-research experience and the identification of new dimensions of self-evaluation, self-observation and attention serve as a basis to think about the importance of experiencing the understanding within the ambit of the school. The reflections about my actions and those of the teachers bring up the hypothesis that the misunderstandings in the teaching-learning process and in the affective relations are the result of a fragmented, naive and egotistic way of thinking. Thus, they don t contribute to an experience of mutual understanding. That is why there must be an investment on new strategies of self-research and dialogue within the scope of pedagogical meetings that may come to help all educators with the analysis, identification and solving of their own problems as well as the other s. Under this perspective, the question that guides this study assumes the presupposition that the educator can invest in a qualified and meaningful pedagogical formation, either one s own and others , if one has a critical-reflexive overview about oneself and the school s pedagogical process. This research aims to explore, discuss and encourage new reflections about the act of researching in the pedagogical supervisor s role, questioning about the possibility of this action to generate contributions to the process of one s own and other s pedagogical formation within the scope of the school, in a conscientiological perspective, in which the manifestation of the thosenes of the educators are valorized. We approach Paulo Freire (1921-1997), as we see the dialogue as very important to the development of this research work, as well as an encouragement to the consciential dialogue. The empirical research took place from June 4, 2004 to November 11, 2004, with 8 pedagogical meetings and with the participation of 2 pedagogical supervisors and 8 teachers. The application of this new methodology within the scope of pedagogical meetings brought considerable contributions to the interpretation of the elements of the educators thosenes, classified according to the following: uncritical, naïve and critical thoughts; sentiments of assistential or non-assistential affectivity; and actions that may or not make the experience of mutual understanding possible. The action of the pedagogical supervisor and one s contributions to the understanding brought up reflections about new ways of investing in the process of continued formation within the scope of the school

Aplicação de técnicas de aprendizado de máquina no reconhecimento de classes estruturais de proteínas

Nowadays, classifying proteins in structural classes, which concerns the inference of patterns in their 3D conformation, is one of the most important open problems in Molecular Biology. The main reason for this is that the function of a protein is intrinsically related to its spatial conformation. However, such conformations are very difficult to be obtained experimentally in laboratory. Thus, this problem has drawn the attention of many researchers in Bioinformatics. Considering the great difference between the number of protein sequences already known and the number of three-dimensional structures determined experimentally, the demand of automated techniques for structural classification of proteins is very high. In this context, computational tools, especially Machine Learning (ML) techniques, have become essential to deal with this problem. In this work, ML techniques are used in the recognition of protein structural classes: Decision Trees, k-Nearest Neighbor, Naive Bayes, Support Vector Machine and Neural Networks. These methods have been chosen because they represent different paradigms of learning and have been widely used in the Bioinfornmatics literature. Aiming to obtain an improvment in the performance of these techniques (individual classifiers), homogeneous (Bagging and Boosting) and heterogeneous (Voting, Stacking and StackingC) multiclassification systems are used. Moreover, since the protein database used in this work presents the problem of imbalanced classes, artificial techniques for class balance (Undersampling Random, Tomek Links, CNN, NCL and OSS) are used to minimize such a problem. In order to evaluate the ML methods, a cross-validation procedure is applied, where the accuracy of the classifiers is measured using the mean of classification error rate, on independent test sets. These means are compared, two by two, by the hypothesis test aiming to evaluate if there is, statistically, a significant difference between them. With respect to the results obtained with the individual classifiers, Support Vector Machine presented the best accuracy. In terms of the multi-classification systems (homogeneous and heterogeneous), they showed, in general, a superior or similar performance when compared to the one achieved by the individual classifiers used - especially Boosting with Decision Tree and the StackingC with Linear Regression as meta classifier. The Voting method, despite of its simplicity, has shown to be adequate for solving the problem presented in this work. The techniques for class balance, on the other hand, have not produced a significant improvement in the global classification error. Nevertheless, the use of such techniques did improve the classification error for the minority class. In this context, the NCL technique has shown to be more appropriated

A construção estilística das identidades poéticas da cidade de Natal: um olhar bakhtiniano

The purpose of this work is to bring forward cultural identities of the city of Natal that are built upon representations contained in the work of Twentieth-Century Potiguar1 poets. We started out with the premise that the urban tissue owes its formation to the effect of the feelings produced and to the individuals that give shape to them, thus causing the city to abound with feelings and meanings that are relevant for both society and the individual. As cities and their identities may be studied and interpreted from different viewpoints, we have used in this study poetic discourse that functions as a memory to the city and takes shape out of a set of historically established social practices. Our research is situated within the area of Applied Linguistics, an area of knowledge focused mainly in language that is increasingly expanding its investigation limits in an interdisciplinary way. Therefore, this study is based on a social and historical model of language, with language construed as a discourse practice (Bakhtin and Circle), and presents an interface with cultural studies (Hall, Canclini), taking into account the fact that culture builds up values and brings forth differences in respect of the conditions under which such values and differences are produced. In this sense, we have tried to ―listen‖ to what the poets say, by understanding and interpreting the meanings produced by their discourse, in order to identify the formation of the identities of the city that arise out of distinct points of view and diverse stylistic marks. Analysis of these poetic utterances lead to multifold cultural identities of the city, ranging from a naive and multicolored Natal to a city that builds itself on its characters and on to an insurgent, usurped Natal

Uma Análise de métodos de distriubuição de atributos em comitês de classificadores

The objective of the researches in artificial intelligence is to qualify the computer to execute functions that are performed by humans using knowledge and reasoning. This work was developed in the area of machine learning, that it s the study branch of artificial intelligence, being related to the project and development of algorithms and techniques capable to allow the computational learning. The objective of this work is analyzing a feature selection method for ensemble systems. The proposed method is inserted into the filter approach of feature selection method, it s using the variance and Spearman correlation to rank the feature and using the reward and punishment strategies to measure the feature importance for the identification of the classes. For each ensemble, several different configuration were used, which varied from hybrid (homogeneous) to non-hybrid (heterogeneous) structures of ensemble. They were submitted to five combining methods (voting, sum, sum weight, multiLayer Perceptron and naïve Bayes) which were applied in six distinct database (real and artificial). The classifiers applied during the experiments were k- nearest neighbor, multiLayer Perceptron, naïve Bayes and decision tree. Finally, the performance of ensemble was analyzed comparatively, using none feature selection method, using a filter approach (original) feature selection method and the proposed method. To do this comparison, a statistical test was applied, which demonstrate that there was a significant improvement in the precision of the ensembles