Uso de confiabilidade na rotulação de exemplos em problemas de classificação multirrótulo com aprendizado semissupervisionado

The techniques of Machine Learning are applied in classification tasks to acquire knowledge through a set of data or information. Some learning methods proposed in literature are methods based on semissupervised learning; this is represented by small percentage of labeled data (supervised learning) combined with a quantity of label and non-labeled examples (unsupervised learning) during the training phase, which reduces, therefore, the need for a large quantity of labeled instances when only small dataset of labeled instances is available for training. A commom problem in semi-supervised learning is as random selection of instances, since most of paper use a random selection technique which can cause a negative impact. Much of machine learning methods treat single-label problems, in other words, problems where a given set of data are associated with a single class; however, through the requirement existent to classify data in a lot of domain, or more than one class, this classification as called multi-label classification. This work presents an experimental analysis of the results obtained using semissupervised learning in troubles of multi-label classification using reliability parameter as an aid in the classification data. Thus, the use of techniques of semissupervised learning and besides methods of multi-label classification, were essential to show the results

Investigando a combinação de técnicas de aprendizado semissupervisionado e classificação hierárquica multirrótulo

Data classification is a task with high applicability in a lot of areas. Most methods for treating classification problems found in the literature dealing with single-label or traditional problems. In recent years has been identified a series of classification tasks in which the samples can be labeled at more than one class simultaneously (multi-label classification). Additionally, these classes can be hierarchically organized (hierarchical classification and hierarchical multi-label classification). On the other hand, we have also studied a new category of learning, called semi-supervised learning, combining labeled data (supervised learning) and non-labeled data (unsupervised learning) during the training phase, thus reducing the need for a large amount of labeled data when only a small set of labeled samples is available. Thus, since both the techniques of multi-label and hierarchical multi-label classification as semi-supervised learning has shown favorable results with its use, this work is proposed and used to apply semi-supervised learning in hierarchical multi-label classication tasks, so eciently take advantage of the main advantages of the two areas. An experimental analysis of the proposed methods found that the use of semi-supervised learning in hierarchical multi-label methods presented satisfactory results, since the two approaches were statistically similar results

Previsão do índice bovespa por meio de redes neurais artificiais: uma análise comparada aos métodos tradicionais de séries de tempo

Forecast is the basis for making strategic, tactical and operational business decisions. In financial economics, several techniques have been used to predict the behavior of assets over the past decades.Thus, there are several methods to assist in the task of time series forecasting, however, conventional modeling techniques such as statistical models and those based on theoretical mathematical models have produced unsatisfactory predictions, increasing the number of studies in more advanced methods of prediction. Among these, the Artificial Neural Networks (ANN) are a relatively new and promising method for predicting business that shows a technique that has caused much interest in the financial environment and has been used successfully in a wide variety of financial modeling systems applications, in many cases proving its superiority over the statistical models ARIMA-GARCH. In this context, this study aimed to examine whether the ANNs are a more appropriate method for predicting the behavior of Indices in Capital Markets than the traditional methods of time series analysis. For this purpose we developed an quantitative study, from financial economic indices, and developed two models of RNA-type feedfoward supervised learning, whose structures consisted of 20 data in the input layer, 90 neurons in one hidden layer and one given as the output layer (Ibovespa). These models used backpropagation, an input activation function based on the tangent sigmoid and a linear output function. Since the aim of analyzing the adherence of the Method of Artificial Neural Networks to carry out predictions of the Ibovespa, we chose to perform this analysis by comparing results between this and Time Series Predictive Model GARCH, developing a GARCH model (1.1).Once applied both methods (ANN and GARCH) we conducted the results' analysis by comparing the results of the forecast with the historical data and by studying the forecast errors by the MSE, RMSE, MAE, Standard Deviation, the Theil's U and forecasting encompassing tests. It was found that the models developed by means of ANNs had lower MSE, RMSE and MAE than the GARCH (1,1) model and Theil U test indicated that the three models have smaller errors than those of a naïve forecast. Although the ANN based on returns have lower precision indicator values than those of ANN based on prices, the forecast encompassing test rejected the hypothesis that this model is better than that, indicating that the ANN models have a similar level of accuracy . It was concluded that for the data series studied the ANN models show a more appropriate Ibovespa forecasting than the traditional models of time series, represented by the GARCH model

Ser professor de português: o que dizem os discursos reguladores, os alunos e os professores no contexto da formação inicial (UMINHO/Portugal e UFRN/Brasil)

The constitution of being a teacher of Portuguese occurs in a dynamic process involving various factors, such as the requirements of regulatory documents, the context of teacher formation, and the configuration of current society, per se. This study is aimed at reflecting on the initial formation of teachers of Portuguese and on official documents that face this formation, raising the following questions: (1) what does it mean to be a Portuguese teacher? (2) what is the vision of the subjects (teachers and students) involved with the formation of teaching the Portuguese Language? (3) how do these individuals deal with official documents? and (4) how do these subjects discourses relate? To understand the context of the formative processes and the knowledge inherent in them, first we take the studies of Garcia (1999) and Tardif (2002) as a theoretical framework, and to understand and interpret the utterances of the interviewees, we were grounded in the writing of Bakhtin (2003), for whom the object of the Humanities, the sciences of man, is the text, since man is, by nature, an expressive being. We situate this study in the framework of qualitative research. It is a multiple case study that focuses on two contexts: formation of teachers of Portuguese at the University of Minho, Portugal, and the Federal University of Rio Grande do Norte, Brazil. The data that make up the research corpus come from documents elaborated by the Ministries of Education of Portugal and Brazil and were adopted by the two teacher formation institutions cited, from individual interviews involving eight trainer teachers (four from each university), and from two group-interviews (one in each institution), done with students in training. Our analysis is divided into three stages: first, document analysis; second, analysis of the discourse of the teachers in both contexts studied; and, third, analysis of the speech of the students in training. It is noteworthy that our purpose in this research was not to come out with a definition like being a teacher of Portuguese is X, but we are interested, above all, in discussing the issues surrounding initial formation, seeking different points of view, and hearing voices coming from different social positions for better understanding our object of study. Our analysis reveals that the initial formation of teachers of Portuguese, both in Portugal and Brazil, occurs in a complex way, under the influence of various factors, including: (a) difficulties in having the individuals involved adapt to the demands of regulatory agencies; (b) students and teachers adequacy to the organizational model of the post-secondary institution; (c) teachers difficulties to deal with the learning problems of students who have limited schooling basis and come from distinct socioeconomic realities; (d) a search for the establishment of methodologies for teaching and learning the Portuguese Language more adequate to reality; and (e) a search for a definition of professional knowledge needed for the teaching practice

Aprendizado por Reforço com Valores deInfluência em Sistemas Multi-Agente

We propose a new paradigm for collective learning in multi-agent systems (MAS) as a solution to the problem in which several agents acting over the same environment must learn how to perform tasks, simultaneously, based on feedbacks given by each one of the other agents. We introduce the proposed paradigm in the form of a reinforcement learning algorithm, nominating it as reinforcement learning with influence values. While learning by rewards, each agent evaluates the relation between the current state and/or action executed at this state (actual believe) together with the reward obtained after all agents that are interacting perform their actions. The reward is a result of the interference of others. The agent considers the opinions of all its colleagues in order to attempt to change the values of its states and/or actions. The idea is that the system, as a whole, must reach an equilibrium, where all agents get satisfied with the obtained results. This means that the values of the state/actions pairs match the reward obtained by each agent. This dynamical way of setting the values for states and/or actions makes this new reinforcement learning paradigm the first to include, naturally, the fact that the presence of other agents in the environment turns it a dynamical model. As a direct result, we implicitly include the internal state, the actions and the rewards obtained by all the other agents in the internal state of each agent. This makes our proposal the first complete solution to the conceptual problem that rises when applying reinforcement learning in multi-agent systems, which is caused by the difference existent between the environment and agent models. With basis on the proposed model, we create the IVQ-learning algorithm that is exhaustive tested in repetitive games with two, three and four agents and in stochastic games that need cooperation and in games that need collaboration. This algorithm shows to be a good option for obtaining solutions that guarantee convergence to the Nash optimum equilibrium in cooperative problems. Experiments performed clear shows that the proposed paradigm is theoretical and experimentally superior to the traditional approaches. Yet, with the creation of this new paradigm the set of reinforcement learning applications in MAS grows up. That is, besides the possibility of applying the algorithm in traditional learning problems in MAS, as for example coordination of tasks in multi-robot systems, it is possible to apply reinforcement learning in problems that are essentially collaborative

Modelos de dispositivos de microondas e ópticos através de redes neurais artificiais de alimentação direta

This dissertation contributes for the development of methodologies through feed forward artificial neural networks for microwave and optical devices modeling. A bibliographical revision on the applications of neuro-computational techniques in the areas of microwave/optical engineering was carried through. Characteristics of networks MLP, RBF and SFNN, as well as the strategies of supervised learning had been presented. Adjustment expressions of the networks free parameters above cited had been deduced from the gradient method. Conventional method EM-ANN was applied in the modeling of microwave passive devices and optical amplifiers. For this, they had been proposals modular configurations based in networks SFNN and RBF/MLP objectifying a bigger capacity of models generalization. As for the training of the used networks, the Rprop algorithm was applied. All the algorithms used in the attainment of the models of this dissertation had been implemented in Matlab

A Informática como recurso didático para a aprendizagem de Física no ensino médio

The accomplishment of this work was motivated by our concerns, while teacher of Physics discipline, in the medium teaching and in the higher education, where we have been observing a lot of difficulties in the students' acting, to the they try to give pursuit out to their studies of the classroom, because of the lack of appropriate equipments, or even, of a laboratory where they can put in practice the studied contents. The work aims at to build and to test an educational software that it serves as tool auxiliadora in Physics learning in the Medium Teaching, in the area of electricity, with emphasis in the study of the electrodynamic in resistors. The developed software comes as an alternative to the learning problems, putting the computer science as auxiliary tool, because, besides being an alternative in the middle of the technological expansion, endowed with several resources, it stimulates the significant learning, according to David Ausubel's perspective. A software containing a program destined to the applicability of physics contents in the branch of the electricity is presented as an auxiliary tool, where the student can, not just, to review the contents presented at room, as well as for in practice, through a virtual laboratory, some of these contents, besides testing their knowledge through a bank of discursive subjects. The evaluation of the developed software was made submitting him/it to the professionals' of physics area appreciation. Equally, through continuous evaluations, they were made comparisons among the students' of five different groups acting, in the same school, that you/they were used of the program as tool of his auxiliary learning, and the acting of those that didn't use it

O sintoma na psicanálise e na psicopedagogia: do que se trata?

This paper aims to discuss the concept of symptom in psychopedagogy and psychoanalysis, drawing the consequences for the direction of treatment for each of these fields. Learning Problems has been the name given by various fields of knowledge to what does not happen as expected in the learning process. To address these problems several professionals are called upon. Faced with this demand a new field of knowledge is created: the psycho-pedagogy. In Brazil, it is established as a field of work and research from the contributions of Alicia Fernández. This author, supported by the work of French philosopher and educator Sara Paín, takes the concept of Freudian-Lacanian symptom as a fundamental concept to read the so-called "learning problems". Given this one must question whether the concept of symptom Fernandez is really the same as psychoanalysis. Are they the same? If yes, how to sustain as different fields? If not, what are consequences for the direction of treatment for each of these fields? For this study, the theoretical works of Alicia Fernández and Sara Pain were read aiming to clarify the concept of symptom in psychopedagogy. To discuss the psychoanalytic concept of symptom we turned to the texts of Freud, Lacan and commentators in which this issue is discussed. The results show that Pain and Fernandez seek psychoanalysis as a theory to be coupled with others to solve the learning problems. The concept of symptom as a return of the repressed and as an indicator of a sense to be found in the history of the subject is similar to the psychoanalytical one, however, in psychopedagogy other fields of knowledge and techniques are used as reference and these are sometimes incompatible with the concept of symptom presented. The use of psychological tests for the diagnosis, the idea of transference without the notion of subject supposed to know and the proposed treatment are indications of a different treatment approach from what the ethics of psychoanalysis proposes

Psicologia e pobreza no Brasil: limites e perspectivas da produção de conhecimento e atuação do psicólogo

Poverty is a main theme in Brazil: according to official data, poverty reachs 70 million Brazilian people, and, between them, 20 million are unable to provide their basic needs. Psychology, as a welfare profession, and given its historical concerns with social actions, could not be away from this theme. Based on this, we ask: Which answers Psychology can provide, toward both the production of knowledge and the practice about social reality? The purpose of this paper is to investigate the psychological scientific production on poverty and the propositions, limits and impacts of psychological actions. We carried out a three stages documental based study analyzing Brazilian psychological literature: (1) online databases survey (312 papers identified); (2) 109 scientific abstracts accessed and coded; (3) selected 47 scientific papers read and analyzed. Results are presented in three sections: general description of the selected scientific production; characterization of the role of poverty in psychological literature; and themes presented at the papers. The academic production about the main theme (poverty) is dispersed, heterogeneous, and related to other fields of knowledge. Poverty is presented at these studies in many ways, such as: a criterium for sample design and the assessment of its psychological impacts; reports on professional experience with poor population; descriptions of this population group; relationship between poverty and others social themes; developmental and learning problems of poor children. In general, it appears that Psychology has improved the scientific production and experiences with poor population. However, it is necessary to build up theories and technical innovations and also to understand structural boundaries for professional practice with this population group

Problemas de aprendizagem sobre ligações químicas para estudantes de graduação

This research aims at identifying the learning problems in newly undergraduate students at university, interpreting the nature and causes of these problems, offering subsidies to overcome these difficulties and enabling a meaningful learning through which students give meaning to their learning. As an object for this work was chosen the theme Chemical Bonds - where were studied the forces between atoms to form molecules, compound ions and ionic crystalline structures - and is characterized as one of the most important subjects of Chemistry. In research, it was used a questionnaire with five open questions, answered by 147 students from the early periods of degrees in Chemistry at Universidade Federal do f Rio Grande do Norte. The answers revealed uncertainty on the part of students, both conceptual and representation, with superficial justifications, always using the octet rule to describe models of chemical bonds. Results suggest that these students had inadequate training in high school and that the examinations for entrance into the ranks were made according to flexible criteria less demanding in terms of knowledge. These observations have led to the conclusion that for future changes, it is necessary for high schools and in the early periods in universities favoring the adoption of pedagogical approaches in context and applying strategies to overcome the teaching of superficial memorization on Chemical Bonds, which probably have applied to the teaching of other subjects of chemistry

Previsão do índice bovespa por meio de redes neurais artificiais: uma análise comparada aos métodos tradicionais de séries de tempo

Forecast is the basis for making strategic, tactical and operational business decisions. In financial economics, several techniques have been used to predict the behavior of assets over the past decades.Thus, there are several methods to assist in the task of time series forecasting, however, conventional modeling techniques such as statistical models and those based on theoretical mathematical models have produced unsatisfactory predictions, increasing the number of studies in more advanced methods of prediction. Among these, the Artificial Neural Networks (ANN) are a relatively new and promising method for predicting business that shows a technique that has caused much interest in the financial environment and has been used successfully in a wide variety of financial modeling systems applications, in many cases proving its superiority over the statistical models ARIMA-GARCH. In this context, this study aimed to examine whether the ANNs are a more appropriate method for predicting the behavior of Indices in Capital Markets than the traditional methods of time series analysis. For this purpose we developed an quantitative study, from financial economic indices, and developed two models of RNA-type feedfoward supervised learning, whose structures consisted of 20 data in the input layer, 90 neurons in one hidden layer and one given as the output layer (Ibovespa). These models used backpropagation, an input activation function based on the tangent sigmoid and a linear output function. Since the aim of analyzing the adherence of the Method of Artificial Neural Networks to carry out predictions of the Ibovespa, we chose to perform this analysis by comparing results between this and Time Series Predictive Model GARCH, developing a GARCH model (1.1).Once applied both methods (ANN and GARCH) we conducted the results' analysis by comparing the results of the forecast with the historical data and by studying the forecast errors by the MSE, RMSE, MAE, Standard Deviation, the Theil's U and forecasting encompassing tests. It was found that the models developed by means of ANNs had lower MSE, RMSE and MAE than the GARCH (1,1) model and Theil U test indicated that the three models have smaller errors than those of a naïve forecast. Although the ANN based on returns have lower precision indicator values than those of ANN based on prices, the forecast encompassing test rejected the hypothesis that this model is better than that, indicating that the ANN models have a similar level of accuracy . It was concluded that for the data series studied the ANN models show a more appropriate Ibovespa forecasting than the traditional models of time series, represented by the GARCH model

Terapia ocupacional em ação interdisciplinar: jogos educativo-nutricionais na prevenção da obesidade infantil

The inter-subjectivity is the answer in the search for the solution of complex problems, which concerns interfaces of knowledge, respecting their borders. This paradigm is essential in the author's work. So, the search on screen is based on this perspective, by using inter-subject groups of work conduced by professionals of Computer Science, Social Communication, Architecture and Urbanism, Pedagogy, Psicopegagogy, Nutritional Science, Endocrinology, Occupational Therapy and Nursing, it was also part of this group an 8 year old child, daughter of one of the professional who took part of the group. This thesis aims to present the course of investigation developed, analyzing the action of inter-subject Occupational Therapy and Nutrition on the promotion of learning nutritional concepts through educative-nutritional games in order to prevent child's obesity in an educative context. The research was analytic, interventionist and almost experimental. It took place in a public school in Fortaleza, Ceará, Brazil, between August and December 2004. It was selected a sample non-probabilistic, by convenience, of 200 children, born from 1994 to 1996. It was selected almost nonprobabilistically, by convenience, 200 children born between 1994 and 1996. To analyze the results it was used a triangulation, associated by quantitative and qualitative approaches. The basis collect happened through games specially manufactured to these research- video-games, board games, memory games, puzzles, scramble, searching words and iterative basics. There were semi-structured interviews, direct and structured observations and focus in-groups. It was noticed the efficiency of educativenutritional games in the learning process, which lead to a changing of attitude towards the eating choices. These games gave similar results in relation to the compared variations preferences, experience and attitudes, theses attitudes were observed through the game; and the categories to compare the possibility of learning by playing, the fantasy in the learning process, learning concepts of nutritional education and the need of help in the learning process (mediation). It was proved that educativenutritional games could be used to teach nutritional concepts, in an inter-subjective action of Occupational Therapy and Nutrition in schools. The simultaneous application of these games lead to the optimization of child s learning process. It should be emphasized the need of studies about the adaptation of tools used in a child s Nutritional Education, with the help of inter-subjective action. Because just one subject, in a fractionated way can give an answer to complex problems and help to a change of the reality with effectiveness and resolution

Alfabetizar letrando: investigação-ação fundada nas necessidades de formação docente

The accomplished researches in the education field focus on the importance of the accomplishment of actions involved in the analysis of the needs to graduate teachers as a way to adequate to socialcultural changing that require more and more a creative activity to prepare teachers in their graduation perspective. The worry with a fail at school linked to public school students lead us to make this thesis which goals are: investigate the needs of the graduation of teachers at public Elementary Schools concerning to the subjacent knowledge to the development of a pedagogic practice of alphabetizing with literacy and (re)create, with some teachers as active participants in the researches, knowledge regarding the process of alphabetization with literacy , based on the graduation of teachers. The study was accomplished in a municipal Elementary School in the Ceará-Mirim city, located in the state of Rio Grande do Norte, which offers both I and II levels of the Elementary School, 7 teachers and the principal of the school were subjects of our researches. The starting point was the needs of the graduation as subject phenomena, socially created and that allow people to be aware of the goals of a graduation. The investigative broach is qualitative, whose fundamental purpose is the understanding of the meanings, symbols, values and intentions of the mankind actions, as regards to other humanbeing and the contexts in which they interact. Within this context, we chose the investigation-action for we consider this kind of research a place for investigation and professional graduation, in which teachers and the researcher herself assume responsibility of problematizing, build the needs of graduation and think about their practices. As proceedings to create and analyze data, we developed participant observations during the activities in classroom; semi-structured interviews (individual and in groups) with teachers and the principal; analysis of documents and meetings at school for reflexive studies that enabled us to gather data in a pyramidal panoramic view and analyze the contents. The research revealed that the analysis of necessities to graduate teachers is a resource able to contribute to the planning of projects of keeping on graduating more properly, and thus create a critical and reflexive identity for teachers. This way, it was possible the graduation necessities could be revealed and also the knowledge of teachers as regards to alphabetization inserted in a perspective of literacy. Nowadays, conceptualized needs upon difficulties of teachers, there is a tendency to translate them into theorization of problems, without application to these knowledge of teachers, as well as their wishes for changing, especially when those needs are built to analyze and consider concrete practices. Therefore, the graduation experiences have enabled the abandon of a mechanical broach for teaching reading and writing. It has also lead teachers to assume a posture of providing their students the understanding about the reading and writing processes and their functions as social instruments. The graduation theme contents allowed the knowledge to conceive reading and writing in new perspectives, according to their social functions, so that they can improve the education with literacy quality. This theoretical construction has enabled us to understand and consider the necessities of the graduation as progressive process, and has given us the possibility of re-think our own learning processes at the university and review the pedagogical practices of public school teachers. Our conclusion is that once teachers consider their own graduation needs, it contributes to change their concepts and practices in education and literacy, even though there used to be many difficulties in their graduation and organization of the pedagogical work

Estágio Supervisionado na formação de professores em serviço dos anos iniciais do ensino fundamental

This report aims to present the results of research on the possibilities and limits of Supervised Traineeship in a the course of Training of Teachers in Service of the early years of primary education conducted through an agreement between the Federal University of Piauí and the Teresina city council (PI) UFPI/PMT, offers subsidies to teaching practices that address the reality of students who live, work and/or studying in school located in rural areas. The research is based on a theoretical and methodological approach that places the object of study in the critical perspective and using procedures such as: literature (bibliographical research), documentary analysis, semi-structured interview and photographic record. We researched 10 (ten) teachers of the course promoted by UFPI graduating in 2006 and who develop teaching activities in schools located in rural areas in the city of Teresina-PI, 02 (two) teachers who are trainee supervisor of UFPI and the coordinator of the course. The analysis evidenced that the object, historically, educational policies have changed, but did not break the traditional patterns of teacher education, enough, especially in the curricular proposals in light of the changes required by the information and global society. We also note that in the supervised training, the process of critical reflection on teaching practice was made possible, in part, and raised the reconstruction of specific knowledge to make teaching in order to conduct the teaching-learning process articulating different realities of primary teaching and facing situations due to conservative practices in relation to education in rural areas. It contributed, therefore, this curricular component to resize, in part, the pedagogical action of the teachers graduated. The study also drives the research toward to similar studies in the perspective of overcoming the current model of teacher training that does not correspond to the demands of society in change and to the crisis of capital, with immeasurable consequences in the workplace. The contemporary claims for a University to form professionals capable of directing the destiny of society, where teacher training is a social and political demands on which is co-responsible

Educação escolar para crianças: o que dizem sujeitos deste direito?

The text aims to discuss the problems that this would be set: - What are the concepts of public school children about their right to primary education, as required step in the Basic Education? - What are conducted by children on the elementary school, in terms of its structure, teaching, and acquisitions provide for their users, especially when it comes to literacy? In order to answer these questions, we conducted within the qualitative a case study within twenty children of the early years of elementary public school, ten of the School Mauricio de Sousa and ten children of the School Monteiro Lobato. with construction procedures of data, we worked with observation, semi-directive interview, questionnaire and document analysis. In analyzing the data, two categories emerged: right to education and school for children. The first focuses on what children think about the legal guarantee to school, seeking to understand if they understand the educational area as a right and relate what the law says and the reality in which they participate. The category for school children, including their purposes, characteristics, space literacy and its relationship with the teacher. In this sense, we comment, taking as its founding, the speech of children in their schools, focusing on how they perceive the school in terms of its structure and functioning, relations with the knowledge and the other children. With regard to child rights, the appreciation of Brazilian children should be the basis of the struggle for a more just, democratic, nondiscriminatory. However, children show not recognize education as a right, but as one who deserves the credit, that is, those children who are always attentive, do not fight and do not complain. In interviews, children express a simple wish child that the school had toys. A school for children should be a place with its own characteristics: cheerful, lively, colorful, which included the same time, security and challenges. Children point to the hope that the course of action the teacher was guided by respect their differences in a more emotional, especially with regard to issues of authority and discipline of the group. The most important learning is for all subjects learning to read / write, differing in the idea of how to learn. Unfortunately, for some students, learning reading and writing appears as a difficult and enjoyable process is not perceived by some subjects up to recognize the instrumental writing. Finally, we point to the actors of the school to launch a more accurate to say that the children and how to outline your main locus of learning