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Sistema para a oferta de serviços baseados em localização com garantias de privacidade do usuário
(Universidade Federal de São Carlos, 2009-06-02) Ribeiro, Filipe Nunes; Zorzo, Sérgio Donizetti; https://lattes.cnpq.br/2523715806470871; https://lattes.cnpq.br/0077465042842971
The use of geographical information about users is the main quality of Location Based Services (LBS). Services like finding nearest hotels and restaurants, weather forecasting or traffic conditions verifying are some of them that can be found without hard effort. Even though using LBS can be bring out facilities and benefits, manipulation of location information by malicious parties can represent serious threat to users privacy. The mobile telephony has been widely used to offer LBS, mainly due to the powerful increase of mobile devices, location capabilities in the devices and the large number of potential users. Despite the existence of techniques to offer privacy in LBS execution, there is no much interest in using these techniques in the mobile telephony environment, besides, the majority of proposed techniques do not present results that can be used in a real environment. This work presents a system that offers location privacy to mobile phone applications. The expression location privacy points out the competency of avoid that third parties learn about current or past location of the user. Then, we propose the Location Privacy Based System (SBPL), that offers manners to control location information release and allows LBS execution with privacy guarantees to mobile phone users. The SBPL is composed by a client application, performed in the mobile device, and a trusted server, acting between the mobile device and the service provider. Besides, the SBPL follows the recommendations of existing privacy guidelines, and allows the user to determine his preferences, which assure adaptation to distinct users and services. Tests were performed in LBS environments that prove the efficiency of SBPL and the possibility of using it in the mobile phone environment.
Decomposição aeróbia de Myriophyllum aquaticum (Vell.) Verdc. e caracterização limnológica na bacia hidrográfica do rio do Monjolinho (São Carlos, SP, Brasil)
(Universidade Federal de São Carlos, 2009-06-02) Santos, Mariana Gonzaga dos; Bianchini Júnior, Irineu; https://lattes.cnpq.br/0659731944736389; https://lattes.cnpq.br/3205499123721178
The oxidative aerobic processes contribute with large amounts of nutrients in dissolved and particulate forms for the metabolism microbial water. In that context, this study described the oxygen consumption kinetics during the aerobic mineralization of Myriophyllum aquaticum and also evaluated the possible effects of nutrients addiction, the chemical composition and temperature on the decomposition. The aquatic macrophyte was collected in the coastal region of the Monjolinho reservoir (220 00' S and 47054' W; SP, Brazil). In the laboratory part of the plant fragments were subjected to leaching for extraction of the dissolved organic matter (DOM). In the laboratory, part of the plant fragments was subjected to leaching to extract the particulate fraction (POM). The mineralization chambers were set up (n = 96) with different N and P concentrations, entire detritus or lignocellulosic matrix (i.e. fibers) in two phenological stages (senescent or green) under two temperature (16 and 25 ºC), totaling 32 treatments. The concentrations of dissolved oxygen (DO) were determined periodically in the chambers for 80 days. The results were adjusted to a kinetic model of first-order. Different concentrations of N and P did not interfere in the microbial metabolism when the experiments with full detritus and lignocellulosic matrix were analyzed separately. Moreover, in experiments that include the mineralization of macrophytes under natural conditions (with reservoir water), was favoring the mineralization rather than immobilization. However, the independent analysis of the concentrations of N and P showed that the same condition of temperature and type of fragment (green or senescent), the kD was approximately 2 times greater in treatments with full detritus for those with only lignocellulosic matrix, which showed higher C: P and smaller quantities of lignin in their original chemical composition. The Q10 has shown similarities between the treatments, regardless of chemical composition (entire or fibers), but differences in relation to the plant phenological stage (ranging from 1.75 to 2.06). Regarding the stoichiometry O/N was an expense of greater oxygen for nitrification in treatments with full litter (mean = 1%) compared to treatment with lignocellulosic matrix (mean = 0.6%). The quality of detritus was the most important variable in the mineralization of macrophytes the temperature has served as a secondary factor.