Simulations under Ideal and Nonideal Conditions for Characterization of a Passive Doppler Geographical Location System Using Extension of Data Reception Network

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

Improving the passive doppler geolocation system through extension of the data reception network

O objetivo deste trabalho e apresentar uma investigação preliminar da precisão nos resultados do sistema de localização geográfica de transmissores desenvolvido utilizando o software da rede brasileira de coleta de dados. Um conjunto de medidas de desvio Doppler de uma única passagem do satélite, considerando uma Plataforma de Coleta de Dados (PCD) e uma rede de estações de recepção terrestrês, e denominado uma rede de recepção de dados. Assim, a rede brasileira de coleta de dados com o uso de múltiplas estações de recepção permitira o incremento na quantidade de dados coletados com consequente melhora na precisão e na confiabilidade das localizações fornecidas. Consequentemente uma maior quantidade de localizações válidas e mais precisas. Os resultados e análises foram obtidos sob duas condições: na primeira foi considerada uma condição prática com dados reais e dados ideais simulados, para comparar os resultados considerando a mesma passagem do satélite, transmissor e duas estações de recepção conhecidas; na segunda foram consideradas as condições ideais simuladas a partir de medidas de um transmissor fixo, três estações de recepção e dois satélites. Os resultados utilizando a rede de recepção de dados foram bastante satisfatórios. O estudo realizado mostrou a importãncia da instalação de novas estações de recepção terrenas distribuídas no territorio nacional, para um aumento na quantidade de medidas e consequentemente uma maior quantidade de localizações válidas e mais precisas.

Second-order statistics for equal gain and maximal ratio diversity-combining reception

Exact and closed-form expressions for the level crossing rate and average fade duration are presented for equal gain combining and maximal ratio combining schemes, assuming an arbitrary number of independent branches in a Rayleigh environment. The analytical results are thoroughly validated by simulation.

Potential scenarios for Internet use in the mathematics classroom

Research on the influence of multiple representations in mathematics education gained new momentum when personal computers and software started to become available in the mid-1980s. It became much easier for students who were not fond of algebraic representations to work with concepts such as function using graphs or tables. Research on how students use such software showed that they shaped the tools to their own needs, resulting in an intershaping relationship in which tools shape the way students know at the same time the students shape the tools and influence the design of the next generation of tools. This kind of research led to the theoretical perspective presented in this paper: knowledge is constructed by collectives of humans-with-media. In this paper, I will discuss how media have shaped the notions of problem and knowledge, and a parallel will be developed between the way that software has brought new possibilities to mathematics education and the changes that the Internet may bring to mathematics education. This paper is, therefore, a discussion about the future of mathematics education. Potential scenarios for the future of mathematics education, if the Internet becomes accepted in the classroom, will be discussed. © FIZ Karlsruhe 2009.

Antes que o mundo da leitura acabe: um estudo da recepção de uma obra juvenil na escola pública paulista

Pós-graduação em Letras - FCLAS

A arte de educar entre a mimese e o sublime: considerações a partir de Theodor W. Adorno e Jean François Lyotard

Pós-graduação em Educação - FFC

Síndrome de Asperger e educação inclusiva: análise de atitudes sociais e interações sociais

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Towards criterion validity in classroom language analysis: methodological constraints of metadiscourse and inter-rater agreement

This paper reports on a process to validate a revised version of a system for coding classroom discourse in foreign language lessons, a context in which the dual role of language (as content and means of communication) and the speakers' specific pedagogical aims lead to a certain degree of ambiguity in language analysis. The language used by teachers and students has been extensively studied, and a framework of concepts concerning classroom discourse well-established. Models for coding classroom language need, however, to be revised when they are applied to specific research contexts. The application and revision of an initial framework can lead to the development of earlier models, and to the re-definition of previously established categories of analysis that have to be validated. The procedures followed to validate a coding system are related here as guidelines for conducting research under similar circumstances. The advantages of using instruments that incorporate two types of data, that is, quantitative measures and qualitative information from raters' metadiscourse, are discussed, and it is suggested that such procedure can contribute to the process of validation itself, towards attaining reliability of research results, as well as indicate some constraints of the adopted research methodology.

Universal or provincial? early reception of brian friel´s philadelphia, here I come!

This article, part of a larger research work that resulted in a Professorship Thesis, presents a survey and evaluation of the early reception of one of Brian Friel’s first plays: Philadelphia, Here I Come! (1964). The article also explores the question of emigration from Ireland in the 1950s and 1960s, considering British legislation on the matter, and comments on the eventual influence such issue, among other factors, may have had on criticism about the performance of the play at the time.

Competences in the classroom in the perspectives of foreign language teachers

In this article we raise some considerations about teachers’ competences, from the perspective of teachers in the Brazilian public sector. The theoretical framework includes articles by Paulo Freire (2001), Philippe Perrenoud (2012), Edgar Morin (2003) and Maurice Tardif (2002) and, based on these authors, we reflect upon issues concerning teachers’ competences taking answers provided by the Brazilian language teachers as a departing point. In a teachers’ course, followed by the same teachers, we posed the main question in our study: Which competences are necessary for a teacher to be considered a good professional at present? From the answers given individually and group discussions we proceeded to a comparative analysis with the adopted framework, and other issues concerning teachers’ competences were considered as well. All the participants mentioned the same two competences, the use of technology and sound knowledge of the course content, and other competences were pointed out by the various teachers as well. Such procedure, besides providing data for our study, also helped as a self-reflexive activity for the teachers involved, about their own professional performance. Given the issues raised in the theoretical texts and the answers provided by the teachers, we expect to revisit the competences necessary for foreign language teacher efficient performance.

Association of student position in classroom and school performance

We analyzed whether the position of students in classroom is correlated with academic performance, and which factors might be involved. The sample consisted of 16 classrooms in a school year bimester, each one with around 30 students. Each student's position was registered in classroom maps and the reasons for the students' seat choice were gathered by a questionnaire. School performance and classroom absences of each student were collected directly from the teachers' register notebook. We found that better performances of students at school correlate with lower percentages of absence and choices of seating positions closer to the board. Moreover, the main reason to sit in a front position was motivation for learning. We suggest that school performance is associated to students’ position in the classroom because both are affected by the student motivation for learning. As a consequence, changing students' position in the classroom without increasing their motivation is not likely to improve school performance.

Geografia, patrimônio e diversidade cultural: linguagem audiovisual em ações educativas

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)