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Emprego de estratégias quimiométricas para a diferenciação de alimentos de acordo com as formas de produção
(Universidade Federal de São Carlos, 2006-11-14) Fernandes, Andréa Pires; Nóbrega, Joaquim de Araújo; https://lattes.cnpq.br/8833989058164529; https://lattes.cnpq.br/3964313181351411
The application of pattern recognition techniques such as principal component analysis and cluster analysis was evaluated for classification of foods according to their production mode (industrial or homemade and organically or conventionally produced), refine mode or geographical source. The main variables were the mineral contents of samples of coffee (roasted and green), vegetables, legumes, sugar, milk, sugar-cane spirit, beans, and rice. The concentrations of metals were determined by ICP OES or by GF AAS after microwave-assisted digestion or dilution. Other variables, such as nitrate and crude protein contents, were determined in vegetables and legumes samples. Nuclear magnetic resonance of 1H was applied to green coffee and beans to attempt to correlate chemical classes with production mode. Separations were obtained for differentiation between organic and conventional green coffees, and between instant soluble and roasted coffees. Attempts to correlate metals contents with geographical sources for coffee and sugar samples, and metals contents and production mode for vegetables, legumes, milks, sugar cane spirits, and rices were not successful. However, differentiation was observed for lettuces and cachaças based on geographical source, and for sugar samples based on the refine mode. Additionally, differentiation was also observed for lettuce samples based on the production mode, and nitrate was the main variable for differentiation. It was observed a trend towards the classification of beans according to the production mode based on NMR data set, however it is necessary to identify the chemical compounds that led to differentiation. According to these results, pattern recognition analyses were able to differentiate some important features in different samples based on their metals contents. Additionally, taking into account metals contents there was no appreciable difference between organically and conventionally produced foods.
Sistema de integração de técnicas de proteção de privacidade que permitem personalização
(Universidade Federal de São Carlos, 2006-11-14) Grande, Robson Eduardo de; Zorzo, Sérgio Donizetti; https://lattes.cnpq.br/2523715806470871; https://lattes.cnpq.br/2500050931586103
The interface implementation in e-commerce applications must consider two aspects: the privacy necessities of the user and the marketing utilization by the personalization application in services provided by sites in the Web. In this context, there are several mechanisms developed as to accomplish the data gathering as to bring to the user certain privacy level. Sites use since formularies in Web pages until techniques as clickstream, cookies and data mining to obtain information, to analyze them and to accomplish personalization. Current mechanisms for privacy protection are limited in their ability to provide privacy guarantees to data gathered on the Web, and some of them don t allow the data gathering by Web sites. The MASKS system manages the anonymity of its users and allows the implicit collecting of data. It neither provides security in the explicit gathering and nor allows the creation of browsing sessions via grouping of cookies into groups of different interests. Project 3P introduces a mechanism to keep users aware of privacy policies while they navigate Web sites. It adds low reliance to the implicit gathering. Here, we introduce a new system that combines an extension of MASKS system, an extension of P3P and an architecture of privacy certification. This combined system gathers the best qualities of each mechanism, and removes their limitations. The extended MASKS system includes sessions in the masking proxy to enable the creation of browsing sessions. The extended P3P adds information about the user benefits in disclosing his/her data to Web services. The privacy certificates guarantees the accomplishment of the policies stated by sites. Tests with users were carried out in order to compare and to evaluate the advantages of using this newly combined system. The results showed that the combined system provides users navigation with higher reliability. Thus, the implementation of this system proves useful for providing privacy during Web browsing, without impeding data gathering.