O olhar dos alunos e dos professores sobre a informática no curso de licenciatura em matemática na UFPA

Este trabalho visa investigar os saberes manifestados pelos alunos do curso de Matemática na Universidade Federal do Pará (UFPA), em relação à utilização da informática em sua formação. Para atender esse objetivo, utilizamos uma metodologia referente ao estudo de caso. Fizemos um breve histórico sobre a informática educativa no Brasil, destacamos os avanços e pesquisas na área e abordamos as principais maneiras de utilizá-los na educação; tratamos dos aspectos relacionados à Educação Matemática com alguns softwares educativos e as experiências com o uso do computador; e, em seguida, passamos para a nossa investigação, fundamentada nos documentos escritos pelos alunos e professores do curso de Licenciatura em Matemática da UFPA. As informações foram obtidas por meio de questionários aplicados aos alunos, durante o segundo semestre letivo de 2004, e aos professores no primeiro semestre letivo de 2005. Pudemos observar, nas análises, que alunos e professores consideram muito importante a inserção da informática ao currículo da Licenciatura em Matemática, porém destacam que este ensino ainda não ocorre e há necessidade de que ele faça parte efetiva da formação dos professores de Matemática, pois, pode contribuir para a melhoria do processo de ensino aprendizagem e é uma ferramenta indispensável para a educação.

Código de modernidade e sistemas antigos: a propósito do uso da informática pelos professores de matemática da rede pública estadual em Belém

O uso das Tecnologias da Informação e Comunicação -TIC no ambiente escolar, além de permitir o acesso a um universo de informações tão caótico quanto inimaginável, promoveu uma profunda transformação na relação de seus principais atores -professores e alunos - com o conhecimento. Desde o final da década de 1980 que, no Brasil, diversos programas surgiram com a finalidade de prover a educação pública de condições de igualdade com a educação privada, procurando através da inserção nas escolas da rede municipal e estadual de um ambiente tecnológico de aprendizagem com base em rede de computadores conectados a Internet, garantir o ansiado salto de qualidade do ensino público. A proposta desse trabalho é investigar se os professores de Matemática que atuam nas escolas da rede estadual em Belém/P A, que possuem Laboratório de Informática, estabelecem interações com esse ambiente na busca pela melhoria de sua práxis pedagógica, favorecendo a transmissão de informações, a construção de conhecimentos e de conceitos matemáticos.

Formação de professores e informática. Da falta de teoria à necessidade da prática: o caso de uma escola agrotécnica

O presente trabalho foi desenvolvido no intuito de identificar as razões das dificuldades enfrentadas pelos docentes no que se refere à utilização da informática na prática pedagógica, para poder propor a superação das mesmas e consequentemente contribuir para a consolidação da informática educativa nas atividades docentes. Com o desenvolvimento desta pesquisa foi observado que a própria prática pessoal da metodologia aplicada à disciplina “Informática Aplicada” do curso técnico em agropecuária indicava um bom caminho a superação de parte das dificuldades identificadas, embora até então esta prática estivesse dissociada de uma fundamentação teórica específica. Deste modo procuramos, através deste trabalho, formalizar alguns conceitos e sistematizá-los para que, uma vez identificada a raiz do problema, possamos propor uma metodologia de trabalho baseado na Pedagogia de Projetos que possa promover a superação das dificuldades. A analogia com o ciclo de desenvolvimento de softwares demonstrou que a adoção de um procedimento cíclico para o desenvolvimento de projetos de trabalho voltados para o uso da informática na prática docente representa uma boa ferramenta metodológica capaz de favorecer a reflexividade sobre as práticas docentes, promovendo a interdisciplinaridade e a transdisciplinaridade, transformando a informática educativa numa ferramenta de ligação entre as disciplinas, rompendo com a visão fragmentada de uma disciplina específica voltada apenas ao uso do computador e/ou apenas restrita ao laboratório de informática. Por fim, destacamos a necessidade da formação contínua e continuada dos docentes para a efetiva incorporação da informática educativa à sua prática pedagógica, pois, estando habilitados para o emprego das novas tecnologias e conhecendo como podem desenvolver projetos pedagógicos com elas, os docentes se sentirão encorajados em utilizá-las em ações curriculares escolares as mais criativas.

OntoSDM: an approach to improve quality on spatial data mining algorithms

The increase in new electronic devices had generated a considerable increase in obtaining spatial data information; hence these data are becoming more and more widely used. As well as for conventional data, spatial data need to be analyzed so interesting information can be retrieved from them. Therefore, data clustering techniques can be used to extract clusters of a set of spatial data. However, current approaches do not consider the implicit semantics that exist between a region and an object’s attributes. This paper presents an approach that enhances spatial data mining process, so they can use the semantic that exists within a region. A framework was developed, OntoSDM, which enables spatial data mining algorithms to communicate with ontologies in order to enhance the algorithm’s result. The experiments demonstrated a semantically improved result, generating more interesting clusters, therefore reducing manual analysis work of an expert.

Contribuição da Teoria Ator-Rede (T A-R) para o estudo da construção do conhecimento geográfico: uma leitura da introdução da New Geography no Brasil através da Sociologia das Associações

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Detecção de impressões digitais falsas no reconhecimento biométrico de pessoas

Pós-graduação em Ciência da Computação - IBILCE

Analysis of the Dielectric Behavior of Distribution Insulators Under Non-Standard Lightning Impulses Voltages

Overhead distribution lines are often exposed to lightning overvoltages, whose waveforms vary widely and can differ substantially from the standard impulse voltage waveform (1,2 - 50). Different models have been proposed for predicting the strength of insulation subjected to impulses of non-standard waveforms. One of the most commonly used is the disruptive effect model, for which there are different methods for the estimation of the parameters required for its application. This paper aims at evaluating the dielectric behavior of medium voltage insulators subjected to impulses of non-standard waveforms, as well as at evaluating two methods for predicting their dielectric strength against such impulses. The test results relative to the critical lightning impulse flashover voltage (U50) and the volt-time characteristics obtained for the positive and negative polarities of different voltage waveforms are presented and discussed.

The Brazilian Experience With the Use of the Shield Wire Line Technology (SWL) for Energy Distribution

This paper presents an analysis of the impact of the lightning overvoltages on the operational performance of the energized shield wire line technology (SWL) implemented in two locations of the State of Rondonia, Brazil. The analysis covers the periods of 1996 to 2000 (SWL Jaru) and 1997 to 2002 (SWL Itapua do Oeste), and shows that lightning is responsible for most of the system outages. The paper describes the satisfactory results achieved with the system, showing that the isolation and energization of the shield wires does not deteriorate the lightning performance of the 230 kV transmission lines. Comparisons between the performances of the SWL technology, conventional 34.5 kV lines, and thermal power plants in operation in the same region are also presented. The results demonstrate the technical and economical viability of the SWL technology and show that its application can lead to a postponement of investments.

Diagnostic of Silicon Carbide Surge Arresters using Leakage Current Measurement

Nowadays, the zinc oxide surge arresters (ZnO) are widely used in power systems, however, a large number of silicon carbide surge arresters (SiC) are still in service in the utilities. On the other hand, it is not possible to replace all SiC surge arresters in a short time period, being necessary to review the maintenance program taking into account the surge arresters that are more degraded. In this context, a research project was established between the University of Sao Paulo and the electrical utility CTEEP, aiming the investigation of its SiC surge arresters. This work shows that the leakage current measurement, a diagnostic method for the ZnO surge arresters, can provide useful information related to the condition of the SiC surge arresters. Analysis of the amplitude and distortion of the leakage current, also considering thermovision measurements, resulted in better evaluation of the SiC surge arresters.

Color texture analysis based on fractal descriptors

Color texture classification is an important step in image segmentation and recognition. The color information is especially important in textures of natural scenes, such as leaves surfaces, terrains models, etc. In this paper, we propose a novel approach based on the fractal dimension for color texture analysis. The proposed approach investigates the complexity in R, G and B color channels to characterize a texture sample. We also propose to study all channels in combination, taking into consideration the correlations between them. Both these approaches use the volumetric version of the Bouligand-Minkowski Fractal Dimension method. The results show a advantage of the proposed method over other color texture analysis methods. (C) 2011 Elsevier Ltd. All rights reserved.

Robust Hybrid Mechanisms for Scheduling of Grid Tasks

This paper proposes three new hybrid mechanisms for the scheduling of grid tasks, which integrate reactive and proactive approaches. They differ by the scheduler used to define the initial schedule of an application and by the scheduler used to reschedule the application. The mechanisms are compared to reactive and proactive mechanisms. Results show that hybrid approach produces performance close to that of the reactive mechanisms, but demanding less migrations.

Particle Competition and Cooperation in Networks for Semi-Supervised Learning

Semi-supervised learning is one of the important topics in machine learning, concerning with pattern classification where only a small subset of data is labeled. In this paper, a new network-based (or graph-based) semi-supervised classification model is proposed. It employs a combined random-greedy walk of particles, with competition and cooperation mechanisms, to propagate class labels to the whole network. Due to the competition mechanism, the proposed model has a local label spreading fashion, i.e., each particle only visits a portion of nodes potentially belonging to it, while it is not allowed to visit those nodes definitely occupied by particles of other classes. In this way, a "divide-and-conquer" effect is naturally embedded in the model. As a result, the proposed model can achieve a good classification rate while exhibiting low computational complexity order in comparison to other network-based semi-supervised algorithms. Computer simulations carried out for synthetic and real-world data sets provide a numeric quantification of the performance of the method.

Smart histogram analysis applied to the skull-stripping problem in T1-weighted MRI

In this paper we address the "skull-stripping" problem in 3D MR images. We propose a new method that employs an efficient and unique histogram analysis. A fundamental component of this analysis is an algorithm for partitioning a histogram based on the position of the maximum deviation from a Gaussian fit. In our experiments we use a comprehensive image database, including both synthetic and real MRI. and compare our method with other two well-known methods, namely BSE and BET. For all datasets we achieved superior results. Our method is also highly independent of parameter tuning and very robust across considerable variations of noise ratio.

Design of a Comb Generator for High Capacity Coherent-WDM Systems

This paper presents a theoretical model developed for estimating the power, the optical signal to noise ratio and the number of generated carriers in a comb generator, having as a reference the minimum optical signal do noise ratio at the receiver input, for a given fiber link. Based on the recirculating frequency shifting technique, the generator relies on the use of coherent and orthogonal multi-carriers (Coherent-WDM) that makes use of a single laser source (seed) for feeding high capacity (above 100 Gb/s) systems. The theoretical model has been validated by an experimental demonstration, where 23 comb lines with an optical signal to noise ratio ranging from 25 to 33 dB, in a spectral window of similar to 3.5 nm, are obtained.

An Overview of the Use of Metadata in Agriculture

Metadata is data that fully describes the data and the areas they represent, allowing the user to decide on their use as best as possible. Allow reporting on the existence of a set of data linked to specific needs. The use of metadata has the purpose of documenting and organizing a structured organizational data in order to minimize duplication of efforts to locate them and to facilitate maintenance. It also provides the administration of large amounts of data, discovery, retrieval and editing features. The global use of metadata is regulated by a technical group or task force composed of several segments such as industries, universities and research firms. Agriculture in particular is a good example for the development of typical applications using metadata is the integration of systems and equipment, allowing the implementation of techniques used in precision agriculture, the integration of different computer systems via webservices or other type of solution requires the integration of structured data. The purpose of this paper is to present an overview of the standards of metadata areas consolidated as agricultural.