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Métodos de estimação baseados em modelos na presença de dados faltantes
(Universidade Federal de São Carlos, 2022-10-14) Ribeiro, Taís Roberta; Zuanetti, Daiane Aparecida; https://lattes.cnpq.br/8352484284929824; https://lattes.cnpq.br/8535649395348433
The missing data are observations that should have been made, but were not for some reason, thus reducing the ability to understand the nature of the phenomenon, in addition to making it difficult to extract information from the analyzed data, since the impact on the results of the studies is not always known. As a considerable part of the statistical techniques were developed to analyze complete data, the missing data usually need to be treated in such a way that the resulting dataset can be analyzed by such established methods. The most used methods to deal with missing data are divided, mainly, between methods of data removal and imputation, being both configurations, in most cases, disadvantageous in terms of the analysis of the final result, either by making the results biased or because we have to work with the uncertainty associated with the imputation of unknown values. In this work, then, we propose some model-based methods for solving the problem of missing data for regression analysis, without having to resort to imputation or removal of information. We verified the performance of the proposed methodologies on simulated data under different scenarios and compared it with the performance of other traditional techniques of imputation and data removal.
Microcontroladores: definição e implementação de controladores estruturalmente flexíveis para sistemas adaptativos
(Universidade Federal de São Carlos, 2022-10-14) Siqueira, Bento Rafael; De Lemos, Rogério; Ferrari, Fabiano Cutigi; https://lattes.cnpq.br/3154345471250570; https://lattes.cnpq.br/3238780932820205
Context: This work starts from the hypothesis that controllers for adaptive systems that are partitioned into elements, in this work called microcontrollers, which are dedicated to each service involved in the stages of a control loop have the advantage of structural flexibility without compromising the reconfiguration and performance of the target system. Objective: This work aims to propose and evaluate an approach to develop controllers that are structurally flexible (i.e. based on microcontrollers), investigating advantages of the approach by comparing with different configurations of controllers. Methodology: In order to achieve the objective, the following activities were performed: (1) definition of flexible controllers by promoting them as a set of independent microcontrollers, demonstrating them as microservices implementations of the control loops; (2) conduction of an exploratory study and associated qualitative analysis regarding the reconfigurations of the controller; (3) execution of comparative studies to evaluate the approach that is being proposed against other approaches found in the literature; and (4) specification of an implementation by using the microcontroller-based approach, to demonstrate the flexibility of the approach. Results: the results and contributions are: an approach to define controllers that are structurally flexible; an exploratory study involving a qualitative analyse about reconfiguration in design time and runtime; a set of comparative studies evaluating different approaches from the literature; a proposal involving the evolution of the multi-layered controller to demonstrate the feasibility of the approach of this work. Conclusion: As conclusion, a multi-layered controller design, based on micro-controllers, provides the basis for defining structurally flexible controllers at operational-time, and may promote reuse at development-time. In addition, even demanding more computational resources, the approach does not impact on the performance and on the reconfiguration of the target system.
Dinâmica de expansão peri-urbana e instrumentos de gestão ambiental sobre áreas protegidas de mananciais no Chile, Brasil e Austrália
(Universidade Federal de São Carlos, 2022-10-14) Candeias, Flaviana Soares; Dupas, Francisco Antônio; https://lattes.cnpq.br/5421344818132855; Moschini, Luiz Eduardo; https://lattes.cnpq.br/2728357583462262; https://lattes.cnpq.br/3269273463587490
Considering the relevance of protected áreas (PAs) used as springs for large urban centers and the pressures they have been suffering with the advancement of urban areas, this work analyzes three PAs and their respective environmental management instruments in different countries of the global southern hemisphere in the Chile, Brazil and Australia, with different socio-environmental and economic realities. The objective is to expand knowledge about the relationship between the variables of land use and the environmental management instruments in force in the area. Through multitemporal mapping of land use, between 1985 and 2020, with LandSat images, Maximum Likelihood classification and in a GIS environment, the changes that occurred in the surroundings and within the limits of the PAs were analyzed. The results indicate a growing urban expansion towards the PAs along with other changes in land use, such as the reduction of vegetation, which influence the quality and quantity of water in springs. Regarding the instruments, problems were identified that converge to inadequate management, in different intensities. To contribute to the maintenance of water resources and ecosystem services in PAs, it is essential that there is an economic investment, monitoring and effective management in the expansion and planning of areas of vegetation linked to urban planning.
Otimização da produção de ácido 3-hidroxipropiônico por Escherichia coli via engenharia metabólica e de processos
(Universidade Federal de São Carlos, 2022-10-14) Batista, Raquel Salgado; Silva, Adilson José da; https://lattes.cnpq.br/3447469350644179; https://lattes.cnpq.br/6792516042003603
The integration of substrates from bioprocesses is of great interest due to the need of destination for them and the possibility of converting them into value-added products. Among these substrates, the hydrolysates from biorefineries and glycerol obtained from the production of biofuels stand out. Listed as an important chemical platform that can be obtained from biomass by the U.S. Department of Energy, 3-hydroxypropionic acid (3-HP) becomes a product option to be obtained from the co-products mentioned above. The production of 3-HP by biological routes presents some advantages over chemical routes and has become increasingly feasible due to the continuous advancement in industrial biotechnology. To make this production feasible, bioprocesses have been developed from recombinant microorganisms. Thus, the application of genetic engineering in the modification of genes related to the metabolic pathway of these microorganisms allows the construction of strains capable of obtaining 3-HP from cheap substrates (e.g., glycerol, glucose, and xylose). A recombinant E. coli strain developed in our research group showed promising results through the β-alanine production route, but the insertion of the 3-HP production pathway in this strain resulted in a deficiency of cofactors, since the last reaction of the pathway is NADPH dependent. Therefore, the regeneration of this cofactor was evaluated by the expression of genes encoding the NADP+ dependent enzyme glyceraldehyde-3-phosphate dehydrogenase, so that the demand for this cofactor by the NADPH dependent pathways could be met. Overexpression of the gapN gene from Streptococcus equi zooepidemicus, which encodes an NADP+ dependent GAPDH, coupled with regulation of endogenous gapA transcription and the use of glycerol as a carbon source, resulted in 147% higher production compared to the control strain. The use of lactose as an induction agent for the lacUV5 promoter was also evaluated in this study and increased the final 3-HP concentration by about 7% compared to the production obtained by the same strain using 1mM IPTG as an induction agent. Furthermore, conditions with O2 restriction in the process showed that, for the pathway studied, 3-HP production is favored under aerobic condition, and oxygen restriction limits production and leads to acetate accumulation by the cell. Taken together, the strategies evaluated led to the second highest production of 3-HP by the β-alanine pathway reported so far in the literature.