The ant colony, known as a self-organized system, can adapt to the environment by a series of negative and positive feedbacks. There is still a lack of mechanistic understanding of how the factors, such as temperature and food, coordinate the labor of ants. According to the Metabolic Theory of Ecology (MTE), the metabolic rate could control ecological process at all levels. To analyze self-organized process of ant colony, we constructed an agent-based model to simulate the energy and population dynamics of ant colony. After parameterizing the model, we ran 20 parallel simulations for each experiment and parameter sweeps to find patterns and dependencies in the food and energy flow of the colony. Ultimately this model predicted that ant colonies can respond to changes of temperature and food availability and perform differently. We hope this study can improve our understanding on the self-organized process of ant colony.

Submitted by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2018-06-20T18:39:36Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação_finalizada.pdf: 1987710 bytes, checksum: 46c6e0b1f07f99706e86684cdd0bd406 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2018-06-20T18:39:46Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação_finalizada.pdf: 1987710 bytes, checksum: 46c6e0b1f07f99706e86684cdd0bd406 (MD5) / Made available in DSpace on 2018-06-20T18:39:47Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação_finalizada.pdf: 1987710 bytes, checksum: 46c6e0b1f07f99706e86684cdd0bd406 (MD5) Previous issue date: 2018-04-23 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / In the Central Amazon, the fisheries are artisanal in character, being practiced by fishermen in rivers and flooded areas. Thus, the main issue addressed in the study is to verify how the hydrological cycle influences the catches of species, considering that the landing is made up of species with different feeding strategies. Firstly, we carried out a previous characterization of the fisheries, in order to determine the main environments and species exploited, as well as, more productive and attractive periods for the fishing activity. We also list the fishing gear used by fishermen with the target species. The characterization indicated that the lake environments are more exploited by the fishermen, however, most of the catches come from the river channels. In relation to the composition of the landing, a total of 34 species were landed, being the jaraqui coarse scale (Semaprochilodus taenirus) and the jaraqui fine scale (Semaprochilodus insignis) the most exploited species. The period of flood presented a significant difference in the catch values per unit of effort (CPUE) when compared to the other hydrological periods. The fishing gear varied according to the environment where the fishing occurred and the species to be exploited. Later, we used generalized linear models (Covariance Analysis - ANCOVA) to determine the influence of the river level on the fisheries in the Lower Solimões River. The analysis of covariance for the flood period showed that all species were influenced by river level, and by fishing effort, there was still a positive interaction between fishing effort and detritus species. During the flood period, the fishing effort positively influenced all species, there was also a positive interaction between fishing effort, detritivorous and herbivorous species and a positive effort in river environments. In the ebb period, only the fishing effort was significant, with a negative interaction between the fishing environment and the effort. In the dry season, only the omnivorous species were influenced by the fishing effort and the level of the river, with negative interaction between fishing effort and omnivorous species. The results found may contribute to the generation of knowledge about fishing activities, providing information for the construction of public policies related to fisheries management in the state of Amazonas. / Na Amazônia Central as pescarias possuem caráter artesanal, sendo praticadas por pescadores em rios e áreas alagadas, sendo altamente influenciadas pela variação do nível do rio. Desse modo, a principal questão abordada no estudo é verificar como o ciclo hidrológico influencia nas capturas de espécies, considerando que o desembarque é constituído de espécies com diferentes estratégias alimentares. Primeiramente, realizamos uma caracterização prévia das pescarias, no intuito de determinar os principais ambientes e espécies explotados, bem como, períodos mais produtivos e atrativos para a atividade pesqueira. Também relacionamos os apetrechos de pesca utilizados pelos pescadores com as espécies alvo. A caracterização indicou que os ambientes de lago são mais explotados pelos pescadores, no entanto, a maior parte das capturas é oriunda dos canais de rios. Em relação à composição do desembarque, foram desembarcadas um total de 34 espécies, sendo o jaraqui escama grossa (Semaprochilodus taenirus) e o jaraqui escama fina (Semaprochilodus insignis) as espécies mais explotadas. O período de cheia apresentou valores positivos na captura por unidade de esforço (CPUE) quando comparado aos demais períodos hidrológicos. As artes de pesca variaram de acordo com o ambiente onde ocorreu a pesca e as espécies a serem explotadas. Posteriormente, utilizamos modelos lineares generalizados (Análise de covariância – ANCOVA) para determinar a influencia do nível do rio sobre as pescarias no Baixo Rio Solimões. A análise de covariância para o período de enchente mostrou que todas as espécies foram influenciadas pelo nível do rio, e pelo esforço de pesca, houve ainda uma interação positiva entre o esforço de pesca e espécies detritívoras. No período de cheia, o esforço de pesca influenciou positivamente todas as espécies, houve ainda uma interação positiva entre o esforço de pesca, espécies detritívoras e herbívoras e um esforço positivo nos ambientes de rio. No período de vazante, apenas o esforço de pesca foi significativo, com uma interação negativa entre o ambiente de pesca e o esforço. No período de seca, apenas as espécies onívoras foram influenciadas pelo esforço de pesca e o nível do rio, com interação negativa entre o esforço de pesca e espécies onívoras. Os resultados encontrados contribuem para a geração de conhecimento sobre atividades de pesca, fornecendo informações para a construção de políticas públicas relacionadas à gestão da pesca no estado do Amazonas.

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The coexistence of species is probably one of the most interesting and complex phenomenon in nature. We constructed an agent based model to study the coexistence dynamics of prey - predator populations by varying productivity levels of producers in fragmented and connected habitats along with different levels of quality of predators. Our results indicated that productivity levels of producers in fragmented and connected habitats along with levels of predator quality are significantly responsible for overall predator - prey population size and survivorship. In the absence of predation, competition between identical prey populations is more probable in connected habitats than in unfragmented or fragmented habitats. Implementing low quality predators in the habitats positively influences the overall coexistence dynamics whereas implementing high quality predators tend to decrease the prey populations. Fragmented habitats provide for greater prey population survival time in highly productive environments but low prey population survival time in less productive environments.

Self-concept is the individual's subjective view of themselves. It impacts interaction with others and, in turn, further the development of the self. Cultural aspects, gender differences, and psychiatric and substance use disorders further impact the subjective view of the self. Structural Analysis of Social Behavior (SASB) is a model rooted in interpersonal theory and the interpersonal circle that divides the self-concept into eight behavioral clusters over love-hate and autonomy-control. The individual's measured self-beliefs can be used in motivational work and treatment. The forensic psychiatric population is complex, with high levels of comorbidity, but little is known about how they view themselves. This study aims to capture their self-concept and examine if different psychiatric diagnostic groups have distinct self-concept profiles. One hundred and six patients who had previously completed the SASB introject questionnaire were included. Demographic data and other variables were also coded from their electronic journal. The participant's descriptives showed differences from the normative group and slight differences between the psychiatric groups. Inferential statistical analysis showed a significant difference regarding the negative clusters between the Neurodevelopmental and Psychosis groups and a trend of differing scores between the Neurodevelopmental and Personality Disorders groups. Study limitations make it hard to point to distinct self-concept profiles, but SASB-results indicate that the patients generally feel positive about themselves. Further research is needed to increase the findings' generalizability and better capture self-concept in comorbid inpatients. / FOR-SATA

Les TIC sont un facteur clé de performance dans les pays développés. Cette thèse s’intéresse à l’adoption des TIC et leur impact sur la performance des PME manufacturières d’un pays en développement. A la suite d’une première partie qui présente le cadre théorique et conceptuel, le reste de la thèse est organisé en trois études empiriques. La première étude propose une modélisation Probit afin d’identifier les déterminants d’adoption des TIC. Le capital humain est la variable explicative la plus significative. Se basant sur la régression linéaire à variables muettes, la causalité de Granger, le test de Kruskal-Wallis et le test de l’ANOVA de Welch, suivis des tests post-hoc correspondants, la deuxième étude met en évidence l’existence d’un fort lien statistique significatif entre le niveau d’adoption des TIC et la rentabilité. Dans une troisième étude, plusieurs modélisations Probit (simple, ordonné et multivarié) ont été testées sur différentes mesures de performance. Nous montrons, premièrement, que les TIC ont un impact positif sur la productivité, la rentabilité et la compétitivité. Deuxièmement, les TIC, le capital humain et la formation sont les déterminants de la performance globale. Enfin, la contribution des TIC à la performance globale est forte lorsqu’elles sont combinées au capital humain qualifié. En définitive, nos résultats empiriques ont montré un effet positif des TIC, du capital humain et du changement organisationnel sur la performance des PME. / ICT is a key performance factor in developed countries. This PhD thesis focuses on the adoption of ICTs and their impact on the performance of manufacturing SMEs in a developing country. Following a first part covering the theoretical and conceptual framework, the rest of the thesis is organized in three empirical studies. The first study uses a Probit model in order to identify the determinants of ICT adoption. Human capital seems to be the most significant explanatory variable. Based on linear regression of dummy variables, Granger causality, Kruskal-Wallis test, ANOVA test of Welch, followed by corresponding post-hoc tests, the second study highlights the existence of a strong statistically significant relationship between the level of ICT adoption and profitability. In a third study, many Probit models (simple, ordered and multivariate) were tested on different measures of performance. Firstly, we show that ICT have a positive impact on productivity, profitability and competitiveness of SMEs. Secondly, ICT, human capital and training are determinants of firm overall performance. Thirdly, when combined together, ICT and highly skilled human resources have an important contribution to the global performance. In conclusion, our empirical results demonstrate a positive impact of ICT, human capital and organizational change on firm performance.

This report focus upon implied volatility for American styled Asian options, and a least squares approximation method as a way of estimating its magnitude. Asian option prices are calculated/approximated based on Quasi-Monte Carlo simulations and least squares regression, where a known volatility is being used as input. A regression tree then empirically builds a database of regression vectors for the implied volatility based on the simulated output of option prices. The mean squared errors between imputed and estimated volatilities are then compared using a five-folded cross-validation test as well as the non-parametric Kruskal-Wallis hypothesis test of equal distributions. The study results in a proposed semi-parametric model for estimating implied volatilities from options. The user must however be aware of that this model may suffer from bias in estimation, and should thereby be used with caution.