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Detecção de ataques a sistemas de reconhecimento facial utilizando abordagens eficientes de aprendizado de máquina em profundidade
(Universidade Federal de São Carlos, 2019-05-21) Souza, Gustavo Botelho de; Papa, João Paulo; https://lattes.cnpq.br/9039182932747194; Marana, Aparecido Nilceu; https://lattes.cnpq.br/6027713750942689; https://lattes.cnpq.br/2368834665313763
Biometrics emerged, in the last decades, as a robust and convenient solution for security systems. However, despite the higher difficulty to circumvent the biometric applications, nowadays, criminals are developing attacks, known as spoofing or presentation attacks, precisely simulating biometric traits of legal users, such as the facial image with high-definition printed photographs. Among the main biometric traits, face is a promising one given its high universality (everyone has a face) and non-intrusive capture. Despite all this, face recognition systems are the ones that most suffer with such frauds given the high availability of facial images of people in the worlwide computer network. In this context, face spoofing detection techniques must be developed and integrated to the traditional face recognition applications in order to preserve their robustness in real scenarios. Deep Learning based methods have presented state-of-the-art performances in many areas, including face spoofing detection. However, the methods proposed in the literature so far present high computational costs, being not feasible in real situations, with significant hardware restrictions. In this context, in this thesis, efficient architectures of deep neural networks for face spoofing detection are proposed. Among the proposed approaches, modifications in the architectures of the Restricted Boltzmann Machines (RBM), generative and efficient models turned into deep discriminative neural networks, as well as modifications in the architecture of the Convolutional Neural Networks (CNN), expanding them in width instead of depth, and a novel training algorithm for CNNs, able to capture local spoofing cues of different parts of the faces, allowed a significant reduction on the amount of parameters and operations required for processing the facial images, as well as a faster convergence of the deep neural networks, allowing them to reach accuracy results, in attack detection, compatible with the state-of-the-art, at lower computational costs.
Ações sustentáveis desenvolvidas pela rede sociotécnica da Cooperativa Mista Flona Tapajós: uma contribuição para o desenvolvimento local
(Universidade Federal de São Carlos, 2019-05-21) Nobre, Deusa Nara Viana; Abreu, Lucimar Santiago de; https://lattes.cnpq.br/7025928931374268; https://lattes.cnpq.br/1768067327960343
The Flona Tapajós region is part of the National Conservation Unit System (SNUC) of the Amazon biome and is located in western Pará. It is a region of high ecological and social importance, but is threatened by predatory human exploitation of natural resources and the lack local development public policies that favor development actions inspired by ecologically based productive models. However, in recent years, a set of sustainable actions has been developed by a multi-actor network, whose key agent is the Flona Tapajós Mixed Cooperative, called Coomflona. These actions sought to generate a favorable environment for local development through the natural preservation and improvement of the quality of life of Flona Tapajós traditional families. Thus, the objectives of the work were: to identify and analyze the social impact of actions developed by the Cooperative Flona Tapajós Mixed (COOMFLONA), as a way to subsidize, qualify, enhance the social experience and boost the local development of the traditional communities of Flona Tapajós. and build an inventory of the actions taken. The research was conducted through a review of the bibliography accessed through the Internet and a set of interviews with producers from the communities of São Domingos, Maguari and Jamaraçá and representative of the cooperative. It was concluded that the actions of the socio-technical network contributed to the strengthening of local governance, as they sought to meet the demands of family farming communities and generated an environment conducive to improving the quality of life of traditional Flona Tapajós families. Thus, the social organization and the dynamism engendered by the cooperative socio-technical network provided the communities of the Tapajós National Forest with a set of alternatives, providing positive socioeconomic impacts on the generation of income, construction and maintenance of roads to flow the production and marketing of timber and non-timber forest products.
Síntese de celulose bacteriana a partir de resíduos lignocelulósicos via evolução adaptativa
(Universidade Federal de São Carlos, 2019-05-21) Vasconcellos, Vanessa Molina de; Farinas, Cristiane Sanchez; https://lattes.cnpq.br/9933650905615452; https://orcid.org/0000-0002-9985-190X; https://lattes.cnpq.br/9050729757066272; https://orcid.org/0009-0007-3125-1557
Bacterial cellulose (BC) is produced mainly by the Komagataeibacter genus. BC is a biopolymer free of impurities, built from the interlacing of cellulose nanofibers, which presents remarkable properties, such as: high mechanical strength, high water retention capacity, susceptibility to chemical modifications and biocompatibility. The BC is a product of great interest in several biotechnological applications, ranging from noble applications, e.g. medical and pharmaceutical fields, to less sophisticated ones, e.g. reinforcement material in polymers. For the BC synthesis is necessary that the culture medium be rich in glucose, one of the key points that increase the final product. In this context, the present thesis aims to contribute to the reduction of costs involved in the process of CB synthesis using as substrate an alternative source of C: the liquid hot water (LHW) pretreated liquid fraction of lignocellulosic wastes (corn stover and sugarcane bagasse) produced in biorefineries. A challenge to be overcome is related to the presence of inhibitors in the medium, and bypassing this barrier with the addition of a detoxification step with activated charcoal, for example, implies an increase in process cost. The alternative presented in this work was to obtain an inhibitor resistant cellulose producing strain through the adaptive laboratory evolution technique, using the HLW pretreated liquid fraction from corn stover as culture medium. The development of the adapted K. hansenii strain makes possible to directly convert, and thereby concentrate, a dilute form of glucose into an insoluble, readily recovered and value-added cellulose product. While genetic stability, its nature and mechanisms behind the synthesis still need to be revealed, the evolutionary adaptation of this nanocellulose-producing bacteria not only made the bacterium resistant to inhibitors but also capable of producing significantly more nanocellulose compared to the original strain. In addition, the nanocellulose of the adapted strain maintained the same properties as those produced in the standard culture medium.
Avaliação de condições ambientais de nascentes de cursos de água: ferramenta de subsídio à gestão de recursos hídricos e ao planejamento de bacias hidrográficas
(Universidade Federal de São Carlos, 2019-05-21) Pinto, Mauricio José Rosso; Hanai, Frederico Yuri; https://lattes.cnpq.br/7651828454575175; https://lattes.cnpq.br/0029934262855663
The protection, conservation, assessment and monitoring of natural water sources are the foundation for integrated water management and environmental planning of a watershed. Springs are important water sources, they are defined as an environmental system established by geomorphological features or geological structures, in which the outcrop of groundwater occurs in a temporary or perennial way, forming drainage channels downstream. The springs have fundamental ecological and ecosystem functions, as the maintenance of the hydrological cycle, therefore it is necessary to develop mechanisms to guarantee its conservation. The aim of this research was to investigate, identify and analyze parameters, indicators and tools related to assessment, conservation, monitoring and sustainable use of springs, in order to elaborate an integrated assessment tool for their environmental conditions that subsidize water resources management and watershed planning. For this, a Systematic Bibliographic Review (SBR) was developed to identify scientific articles and documents related to springs, showing the different approaches through which, the springs have been studied. After that, those articles and documents were analyzed to find proposals or applications of parameters, indicators, tools and instruments related to assessment, conservation, monitoring, management and/or use of springs. As a result, the list of these parameters, indicators, tools and instruments was obtained and validated by a three-step process (3S): self-validation; scientific validation and social validation. The result of this process was the elaboration of an Integrated Assessment and Monitoring Protocol for Springs (PANÁgua), which was tested through field applications and optimized according to the results of this experience and the significant contributions of the specialists who participated in the validation process. The PANÁgua is a protocol composed by three stages of application and some categories of evaluation that integrate a group of parameters and indicators related to the spring’s conservation state. Finally, this protocol was used to evaluate the environmental conditions of some springs of the Ribeirão do Tamanduá and Córrego Mineirinho watersheds located at the state of São Paulo, Brazil. Many impacts were found with the application of PANÁgua, some of them are the low density of natural vegetation coverage, as well as the erosion and silting processes because of agricultural and livestock activities that predominate in the area. In addition, the evaluation of the water quality showed the presence of total coliforms and high values of electrical conductivity in most springs. Both watersheds evaluated presents different characteristics of the land cover use, that’s why some impacts of the Córrego Mineirinho urban springs were evidenced in more critical conditions, for instance the discharge of sewage and solid waste as springs and the severe degradation of soil in general. The PANÁgua has shown to be a useful and efficient tool that synthesizes and assess the environmental conditions of the springs in a coherent way and can be used to help the environmental agencies in the decision-making processes related to integrated water resource management and watershed environmental planning.