http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/4344 Tue, 07 Jul 2026 14:56:38 GMT 2026-07-07T14:56:38Z http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/9856 Título: Análise topológica em imagens 3D de otólitos de peixes: explorando padrões de densidade e de morfologia Autor: SOUZA NETO, João Valério de Primeiro orientador: DUARTE NETO, Paulo José Abstract: In this thesis, we present a comparative study of otolith density variations using Topological Data Analysis (TDA). Otoliths are calcium carbonate structures found in the inner ears of fish and are commonly used to study age and growth patterns in fish populations. Traditionally, the analysis of otolith density variations has been a computationally intensive task due to the high-dimensional nature of the data. However, TDA offers a promising approach to reduce the data dimensionality and extract meaningful topological information from otolith images. We applied the Ball Mapper algorithm to a dataset of 3D otolith images from different fish species and ages. The algorithm allowed us to construct topological graphs representing the density variations in otoliths. We also explored the use of probabilistic sampling techniques to reduce the data and found that a sample size of 5% provided accurate representations of otolith density variations compared to the full dataset, after a Sample Topological Validation procedure developed here to ensure the efficiency and reliability of the sampling process. Topological invariants of the graphs, such as average clustering, node connectivity, assortativity, shortest path length, efficiency, and others, were used to comparizon between graphs. The comparizon of the topological properties of the full dataset with those of the 5% sample found a high degree of similarity, indicating that TDA with a reduced dataset can capture essential density information. Ball Mapper further allowed us to identify and eliminate dirt or anomalies present in otolith images, further enhancing the accuracy of our analysis. Overall, our study demonstrates the efficacy of TDA in studying otolith density variations with significant computational gains over traditional methods. The reduced data size using probabilistic sampling and the robustness of topological invariants provide valuable insights into the density patterns of otoliths. Another TDA technique, Persistent Homology (PH), was applied to the 3D image data with the expectation of unveiling a new classifier for otolith shape. PH demonstrated prominence even in a small sample by effectively separating otolith classes and revealing accurate quantitative separation results, showcasing potential use for otolith classification based on their 3D structure. Finally, a regression analysis demonstrated the possibility of estimating age, length, and radiodensity of otoliths based on the topological features resulting from the classification. Instituição: Universidade Federal Rural de Pernambuco Tipo do documento: Tese Fri, 23 Feb 2024 00:00:00 GMT http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/9856 2024-02-23T00:00:00Z http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/9832 Título: Correlações entre as séries temporais de queimadas e variáveis climáticas nos biomas brasileiros Autor: PESSOA, Ruben Vivaldi Silva Carneiro Primeiro orientador: STOSIC, Tatijana Abstract: Forest fires are complex phenomena, influenced by a set of climatic factors, in addition to human interference. In Brazil, these fires affect all biomes. Therefore, the study of these fires is necessary due to their negative effects, including not only environmental damage, but also greenhouse gas emissions and economic losses. In this scenario, understanding the temporal and spatial distribution of these fires is challenging, due to the variation in their natural behavior. This study seeks to address this issue, using fractal techniques to analyze the long-term temporal and spatial correlations between fires in Brazilian biomes during the period from 2002 to 2022. The results for the Amazon, Caatinga, Cerrado, and Atlantic Forest biomes showed that in the daily series of fire anomalies and climate variables (relative humidity, maximum temperature, rainfall, and wind speed), there are persistent long-range correlations, in which the persistence of fires was strongest in the Amazon biome and weakest in the Atlantic Forest. Climate variables are more persistent in the Caatinga biome and less persistent in the Atlantic Forest. Furthermore, persistent long-range cross-correlations were observed between the series of climate variables and fires in the four biomes. For the Amazon, Caatinga and Cerrado biomes, the DCCA correlation coefficient values indicated positive correlations between fires and the maximum temperature and wind speed variables, and negative correlations between fires and the relative humidity and rainfall variables. For the Atlantic Forest biome, the correlations between fires and the maximum temperature variable were positive and negative for the other climate variables. Instituição: Universidade Federal Rural de Pernambuco Tipo do documento: Tese Thu, 16 Jan 2025 00:00:00 GMT http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/9832 2025-01-16T00:00:00Z http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/8757 Título: Modelagem computacional de ecossistemas com competição por recursos e evolução em ambientes heterogêneos Autor: DAZA, Sara Lucia Castillo Primeiro orientador: OLIVEIRA, Viviane Moraes de Abstract: In this thesis we study an ecosystem model with a spatial structure in which species compete for resources and evolve in a heterogeneous environment. Environmental heterogeneity is introduced through the allocation of resources, which are distributed on the network through a fractal landscape generated through the simulation of the fractional Brownian movement. Thus, the roughness of the landscape is controlled by Hurst’s exponent, H. Each species is characterized by a set of half-saturation constants, which define the e ciency of the species in the use of each resource. Only one species is initially introduced into the system, and new species are generated from mutations that occur with probability ѵ. The set of half-saturation constants that characterize the mutant species is obtained from the set of the ancestral species, in which one of the constants is modified and obtained through a normal distribution in which the mean is equal to that of the ancestral species and three di erent values for the variance are studied. In the first part of the work, we studied the behavior of diversity patterns presented by the system. We observed that the mean diversity presented a lower value for H = 0:01 (very rough landscape) for the case in which the probability of mutation of the species is lower. We also verify that the species-area relationship has two power law regimes in which S ~ Az, where the exponents obtained for large areas are greater than those obtained for small areas. We also investigated the relationship between the mean number of species and the Hurst exponent, H. For the highest mutation probability value, we note that a higher value of variance in the distribution of the half-saturation constants leads to less diversity. For the case in which the probability of mutation is lower, we observed an increase in the average number of species with H, and less diversity for the case in which the variance of the distribution of the half-saturation constants is smaller. In the second part of the work we did a more statistical study, where we analyzed the behavior of the distribution of the fluctuations in the temporal evolution of diversity. We also studied the relationship between diversity and di erent mutation probability values. We saw that the stretched exponential distribution provided a good fit of the behavior of heavy tail distributions, as were the distributions of the histograms of increments of diversity. We find an adjustment exponent β ≈ 1 indicating that the system has memory for low mutation probabilities, and an exponent β = 2 for higher mutation probabilities, from which we infer that the system behaves like a Markov process. We also noticed a behavior change in the relationship between the exponent and the β mutation probability. For low mutation probability values this relationship follows a power law. For high mutation probabilities, β becomes independent of ѵ. We realized that changing the fluctuation in diversity only depends on the probability of mutation. Instituição: Universidade Federal Rural de Pernambuco Tipo do documento: Tese Thu, 20 Feb 2020 00:00:00 GMT http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/8757 2020-02-20T00:00:00Z http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/8756 Título: Das estatísticas espaciais, Krigagem e Gi* de Getis-Ord, na interpolação de dados e análise de Clusters em dados de qualidade de leite e raiva bovina Autor: FÉRRER, Moisés Tenório Primeiro orientador: MOREIRA, Guilherme Rocha Abstract: The objectives of this work were to analyze the spatio-temporal distribution of nervous diseases in cattle, identifying the presence of hot spot and cold spot of concentration of cases, to search for associations that explain the occurrence and to estimate the dynamics of the disease over time, in the period 2005-2018 and the spatial variability of the composition of chilled raw milk and to elaborate maps with interpolation of data of the physical-chemical specifications of the milk, in the state of Alagoas and in the mesoregion of Agreste Pernambucano, in 2014 and 2015 and Records of 30,929 were analyzed notifications of nervous diseases throughout Brazil included in the Continental Epidemiological Surveillance System (SivCont), from 2005 to 2018 and 3,863 official reports of refrigerated raw milk samples, collected from 432 tanks of direct expansion in the studied region. Regarding the species affected among the confirmed cases of rabies, the main one was bovine with 8,977 (85.43%) cases, followed by the equine species with 1,143 cases (10.87%). All other species had a relative frequency below 1%. Finally, it is concluded that there is spatial variability for fat, lactose, protein, total solids and defatted dry extract of chilled raw milk produced in the state of Alagoas and in the mesoregion of Agreste Pernambucano and that rabies in cattle is persistent in the country, with variations over time and that, if the surveillance measures do not change, the tendency is for the number of cases to remain constant in a short time. In addition, the variables that are considered to explain the occurrence of rabies cases in the literature and by the PNCRH have little or no influence, requiring future studies that aim to identify variables that better explain the occurrence of rabies cases in Brazil. The degree of spatial dependence and geographically weighted regression and the Gi * method of Getis-Ord of the variables were analyzed by the ArcGIS 10.3 software, the other statistical and transition matrix analyzes were performed using the software and R Studio 3.5.1, with the markovchain package. The spatial analysis showed a predominance of areas with fat content from 3.1 to 3.6g / 100g and areas with fat content from 3.6 to 4.2g / 100g. For the lactose content, a predominant area was observed with 4.32 to 4.45g / 100g and some areas with 4.46 to 4.54g / 100g. There was a low influence of altitude, rainfall and precipitation x altitude interaction on the fat, protein, lactose, total solids and defatted dry matter content in the studied area. Instituição: Universidade Federal Rural de Pernambuco Tipo do documento: Tese Mon, 22 Feb 2021 00:00:00 GMT http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/8756 2021-02-22T00:00:00Z