Three different techniques for measuring wear in brake pads are compared: a gravimetric method (electronic balance), a linear measuring touch probe method, and a three-dimensional laser scanning method. Laboratory-scale wear tests were performed on two different types of brake friction materials: a semi-metallic (SM) and a non-asbestos organic (NAO). All three techniques were able to show clear differences in the wear rates of the materials selected for study. It was observed that choosing only a few points of measurement in the thickness determination using a touch probe can lead to significant errors. These errors were higher than those caused by moisture absorption effects when using the gravimetric method. The laser scanning method proved adequate for investigating the wear profiles produced by braking tests. Results from the tests showed that SM material exhibits a higher coefficient of friction and wear rate than the NAO material. An increase of the contact pressure resulted in increased wear rates for both SM and NAO materials. The ratio between volume loss and mass loss also increased when contact pressure was higher indicating that samples had suffered from compressive deformation.

Discrimination and classification time series becomes almost indispensable since the large amountof information available nowadays. The problem of time series discrimination and classification isdiscussed in [1]. In this work the authors propose a novel clustering algorithm based on a class ofquasi U-statistics and subgroup decomposition tests. The decomposition may be applied to any con-cave time-series distance. The resulting test statistics is proved to be asymptotically normal for eitheri.i.d. or non-identically distributed groups of time-series under mild conditions. In practice thereare many time series that are correlated among themselves. An example that can describe this fact isthe financial markets globalization. When one of these markets is affected by an exogenous factor, achain reaction can affect many others. So the independence condition fail.We are interested in analyzing how the correlation among the groups of time series can affectclassification and clustering methods especially the one proposed by [1]. Empirical results show thatthe proposed method is robust to the presence of correlation among time series. The convergence ofthe test statistic for dependent time series will be one of the goals in this work.

References[1]

Valk, M., Pinheiro, A. 2012: Time-series clustering via quasi U-statistics,J. Time Ser. Anal.,Vol. 33, 4, 608 -619.

A tese de que o conceito espinosista de ideia de afecção, introduzido na Ética, expressa o sentido mais preciso do que seja, para o autor, o conceito de ideia da imaginação. Este texto pretende problematizar essa leitura, procurando fornecer subsídios para a hipótese de que ela não é nem inequivocamente corroborada pelo texto da Ética, nem exigida pela doutrina aí apresentada.

Este texto apresenta o processo de elaboração de um mapa de síntese dos riscos ambientais identificados na bacia hidrográfica do Ribeirão das Anhumas e adjacências, no município de Campinas, estado de São Paulo. Trata-se de uma bacia hidrográfica marcada por características paisagísticas urbanas e rurais, com grande presença de estabelecimentos comerciais e de ensino e indústrias de diversos portes. Os dados que serviram de base para esse trabalho foram coletados de 2003 a 2006 durante o “Projeto Anhumas”, conhecido oficialmente como Projeto de Políticas Públicas no. 01/02952 “Recuperação ambiental, participação e poder público: uma experiência em Campinas”, financiado pela Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP). O presente trabalho de síntese de riscos foi inicialmente pensado no âmbito do Atlas da Bacia do Anhumas mas pode ser examinado de maneira individual embora o melhor fosse consultar os relatórios e mapas das demais equipes do projeto Anhumas (vegetação, solos, caracterização socioeconômica, educação ambiental, etc.) em Torres et al. (2006). Nesse sentido, entendemos que o tema aqui tratado, a síntese de riscos ambientais, possui íntimas conexões com todos os demais temas do Projeto Anhumas.