Computer intensive methods for controlling bias in a generalized species diversity index

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Kin-bias, breeding site selection and female fitness in a cannibalistic Neotropical frog

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

The bias in reversing the Box-Cox transformation in time series forecasting: An empirical study based on neural networks

The Box-Cox transformation is a technique mostly utilized to turn the probabilistic distribution of a time series data into approximately normal. And this helps statistical and neural models to perform more accurate forecastings. However, it introduces a bias when the reversion of the transformation is conducted with the predicted data. The statistical methods to perform a bias-free reversion require, necessarily, the assumption of Gaussianity of the transformed data distribution, which is a rare event in real-world time series. So, the aim of this study was to provide an effective method of removing the bias when the reversion of the Box-Cox transformation is executed. Thus, the developed method is based on a focused time lagged feedforward neural network, which does not require any assumption about the transformed data distribution. Therefore, to evaluate the performance of the proposed method, numerical simulations were conducted and the Mean Absolute Percentage Error, the Theil Inequality Index and the Signal-to-Noise ratio of 20-step-ahead forecasts of 40 time series were compared, and the results obtained indicate that the proposed reversion method is valid and justifies new studies. (C) 2014 Elsevier B.V. All rights reserved.

Cultura da Wikipédia como Política de capacitação compartilhada em meio digital de socialização do conhecimento

Presents a developing laboratory within History of Culture, subject taught in the Library and Archive Studies at UNESP (Marilia). The project is based upon the foundations of research line Information and Technology: students from the second under graduation year participate in the improving of 27 entries in Portuguese language Wikipedia. The aim is to capacitate for scientific reading and writing in digital media, habilitate for the information identification and recuperation and for the interpretation and understanding of formal and contents aspects and its reorganization. It includes activities of search, selection, remix and republishing of texts, images, audio and videos in the convergence of diverse hypertext information sources, supported by tutors with strategic abilities in digital environments. In this sense it was adhered to the international Wikipedia Foundation University Campus Ambassadors project. It’s also aimed to induce sharing and collaboration behaviors with the purpose of creating necessary habits for the informational empowerment in Brazil. As methodology is to optimize the work of individuals already trained in wiki culture and to create in within the subject information sharing programs with a more specialized bias, giving greater credibility to the digital environment. The environment syntaxes helps in the learning of the complementary skills of reading and writing and offers itself as an open repository from which information can be reused. It is, thus, an empowerment strategy in the search of autonomy and self reliance considering intersemiotic knowledge in the edition, visualization and understanding of information in the social web. A second step of a verifying research on the environment’s credibility after the consolidation and dissemination of the entries improvement work is proposed.

Bias in the indexing languages Theorethical approaches about feminine issues

The process of knowledge representation as well as its procedures or tools and its products are not neutral in terms of values; instead they imply moral values. In this context, bias in representation related to prejudice and discrimination, to gender issues, to dicotomic categorization in classification systems or in thesauri and to lack of cultural warrant may arise. Concerning the problem of bias in indexing languages, starting from the initial theoretical reflexions of Brey (1999), Berman (1993), Olson (1998; 2002), Lopez-Huertas Perez & Torres Ramirez (2005), Guimaraes (2006), Hjorland (2008) and Milani et al. (2009), the proposal is to present a preliminary categorization aiming at facilitating the identification of bias concerning feminine issues in indexing languages, to offer a contribution to the theoretical universe of the specific questions of knowledge organization and to present a theme to be discussed by educators and professionals in the areas of cataloging, classification and indexing. If in a society which intends to be politically correct, social attitudes towards stigmatized citizens should be modified, then, the universe of indexing languages, taken as tools of knowledge representation, is a fertile field to sow this reflexion.

Dielectric properties of Sr0.75Ba0.25Nb 2O6 thin films: Bias field, frequency and temperature dependence

Ferroelectric strontium barium niobate solid solutions had received great attention due to their excellent pyroelectric, electrooptic and photorefractive properties. Furthermore, they usually also present very interesting phase transition characteristics. In this work, polycrystalline single phase Sr 0.75 Ba 0.25 Nb 2 O 6 thin films were prepared by a hybrid chemical method and deposited on Pt/Ti/SiO 2 /Si substrates. The temperature dependence of dielectric constant was measured at different frequencies and bias field levels. The presence of two dielectric dispersion regions with relaxor characteristics was observed at distinct temperature ranges, corresponding to the ferro-paraelectric and to a structural phase transition at low temperatures, respectively. A specific dielectric dispersion region, associated with an incommensurate superstructure frequently observed in bulk samples, was not observed in this films probably due to their small grain sizes. © 2002 Taylor & Francis.

Rhamnolipids know-how: Looking for strategies for its industrial dissemination

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