Verbal language is a dynamic mental process. Ideas emerge by means of the selection of words from subjective and individual characteristics throughout the oral discourse. The * Corresponding author. 333 Int. J. Mod. Phys. C 2010.21:333-347. Downloaded from www.worldscientific.com by GEORGE WASHINGTON UNIVERSITY on 02/06/15. For personal use only. 334 G. M. Teixeira et al.goal of this work is to characterize the complex network of word associations that emerge from an oral discourse from a discourse topic. Because of that, concepts of associative incidence and fidelity have been elaborated and represented the probability of occurrence of pairs of words in the same sentence in the whole oral discourse. Semantic network of words associations were constructed, where the words are represented as nodes and the edges are created when the incidence-fidelity index between pairs of words exceeds a numerical limit (0.001). Twelve oral discourses were studied. The networks generated from these oral discourses present a typical behavior of complex networks and their indices were calculated and their topologies characterized. The indices of these networks obtained from each incidence-fidelity limit exhibit a critical value in which the semantic network has maximum conceptual information and minimum residual associations. Semantic networks generated by this incidence-fidelity limit depict a pattern of hierarchical classes that represent the different contexts used in the oral discourse.

Este trabalho apresenta a validação de uma ferramenta computacional gratuita, que serve para obtenção de medidas contínuas de objetos em movimento. O software utiliza técnicas de visão computacional, reconhecimento de padrões e fluxoóptico, para viabilizar o rastreamento de objetos em vídeos, gerando dados de trajetória, velocidade, aceleração e movimento angular. O programa foi aplicado no rastreamento da esfera de um pêndulo aproximadamente simples. A metodologia utilizada para a validação toma como base a comparação dos valores medidos pelo programa, bem como os valores teóricos esperados segundo o modelo do pêndulo simples. O experimento se adequou ao método, pois foi construído respeitando os limites lineares do oscilador harmônico, minimizando as perdas de energia por atrito e tornando-o o mais ideal possível. Os resultados indicam que a ferramentaé sensível e precisa. Desvios menores do que um milímetro na medida da trajetória garantem a aplicabilidade do software em física, tanto em projetos de pesquisa quanto em tópicos de ensino. Palavras-chave: visão computacional, pêndulo simples. This paper presents the validation of a computational tool that serves to obtain continuous measurements of moving objects. The software uses techniques of computer vision, pattern recognition and optical flow, to enable the tracking of objects in videos, generating data trajectory, velocity, acceleration and angular movement. The program was applied to track a ball around a simple pendulum. The methodology used for this validation takes as a basis for comparisons the measured values of the program as well as the theoretical values expected according to the model of a simple pendulum. The experiment is appropriate to the method because it was built within the limits of the linear harmonic oscillator, and energy losses due to friction had been minimized, making it the most ideal possible. The results indicate that the tool is sensitive and accurate. Deviations of less than a millimeter in the measurements of the trajectory ensure the applicability of the software on physics, either in research or in teaching topics. Keywords: computer vision, simple pendulum. IntroduçãoO estudo do movimento no ensino de física ou em laboratórios de pesquisa orbita, quase sempre, entre dois extremos: medidas de fácil obtenção e medidas com alta precisão e contínuas. As primeiras são imprecisas, necessitam de poucos recursos (normalmente se baseiam em cronômetros e réguas) e apresentam valores médios como resultado, comoé o caso comum de experimentos em laboratório do ensino médio. No outro extremo aparecem medidas com alta precisão e contínuas, que utilizam tecnologias exigentes de recursos superiores e que são de difícil operação em relaçãoàs anteriores. O pesquisador/educador que busca medidas contínuas do movimento não encontra opções de instrumentos com características intermediárias.Um importante exemplo dessa dualidade ocorre em instrumentos de análise do movimento humano. Para a compreensão de sua complexidade e caracterizaçãoé essenci...

Recent work has employed information theory in social and complex networks. Studies often discuss entropy in the degree distributions of a network. However, no specific work on entropy exists in clique networks. This work is an extension of a previous study that discussed this topic. We propose a method for calculating the entropy of a clique network and its minimum and maximum values in temporal semantic networks based on titles of scientific papers. In addition, the critical network of moments was extracted. We use the titles of scientific papers published in Nature and Science over ten-year period. The results show the diversity of vocabulary over time, based on the entropy values of vertices and edges. In each critical network, we discover the paths that connect important words and an interesting modular structure.

Work experiences during undergraduate studies can be remarkable in the journey of undergraduate students. The objective of this study was to assess, by analyzing semantic networks, the role of work experiences in the meanings those individuals attribute to professional identity. The sample consisted of 2291 students (60% women) divided into three groups: do not work, work in a field related to their course, work in a field not related to their course. The semantic networks of these groups were composed of words uttered from the professional identity prime. We chose to work with the critical network, obtained from the analysis of the incidence-fidelity indexes of the word pairs. The results evidence that work experiences are related to how undergraduate students attribute meaning to professional identity, in such a way that three different networks were formed for these groups. The network of those who work outside their field was the only one that integrated words with negative content, while the semantic networks of those who do not work and those who work in their field, despite containing words that do not always coincide, present a similar macrostructure. We conclude that work experiences play an important role in the meanings that undergraduate students attribute to professional identity. The study innovates by revealing elements of professional-identity construction, besides allowing for reflections on the effects of work experiences during the college period.