Recentes avanços tecnológicos no sensoriamento remoto e nos Sistemas de Informação Geográfica (SIG) têm proporcionado resultados promissores para as pesquisas arqueológicas, em especial nos levantamentos de campo (prospecção) para a identificação de sítios amazônicos. Imagens de satélite, radar e aerofotogrametria proporcionam a análise de variáveis ambientais relacionadas aos sítios arqueológicos, permitindo estabelecer padrões da ocupação humana no espaço e construir modelos preditivos para identificar novos sítios em áreas com as mesmas características ambientais. Entre essas variáveis, destacam-se a proximidade de rios e lagos e a declividade do terreno, além do tipo de vegetação e dos ecossistemas (áreas com solo exposto, várzeas e matas de igapós). Pesquisas realizadas no rio Trombetas, na serra de Carajás e no rio Tocantins, no estado do Pará, Brasil, apresentaram resultados positivos após a criação e o teste de modelos preditivos para cada uma das regiões. Novos sítios arqueológicos foram identificados e as análises espaciais inter e intra-sítios, realizadas com o SIG, permitiram criar hipóteses sobre possíveis rotas de circulação e a escolha, por antigos grupos indígenas, de áreas para captação de recursos naturais e assentamento.

The present work aimed to investigate the effects of contingent and "non-contingent" negative reinforcement on varying behavior (Experiment I), as well as the effects of two extinction procedures (Experiment II), on behavioral variability. In Experiment I, four experimentally naive male rats were exposed to discrete trial avoidance contingencies (Lag 1 and Aco), according to the following design: Lag 1/Aco/Lag1/Aco. The general avoidance procedure included the presentation of 0.5-s, 0.4-mA electric shocks (US) on fixed time (FT) in the presence of a light (CS). Responses in the presence of the CS turned off the CS, sounded a 0.5-s, 10-dB tone, and avoided the next US programmed to be delivered. If the avoidance response was not emitted, the US was presented at the end of the FT, the CS remained unchanged, and a new trial was immediately initiated. Under the Lag 1 contingency, three-response sequences that differed from the last sequence emitted at the session avoided the US. Under the Yoke contingency, US cancellation was contingent on the emission of a three-response sequence, variable or not, following the same reinforcement distribution obtained in the last Lag session.

This work is dedicated to numerical-computational modeling of viscoelastically damped sandwich beam structures and subject to non-linearity by large displacements. To evaluate the nonlinear effects, the strain field was modeled according to the classical theory of Von Karman and the nonlinear response of the system obtained by combining the Galerkin method and the Harmonic Balance method. In order to represent the effects of damping on the Galerkin base, it was necessary to solve the complex eigenvalue problem, and in this case, an iterative method was proposed so that the undamped natural frequencies converged to the damped frequencies. The costly computational effort during the calculation of the complex eigenvalues was reduced thanks to the model reduction method proposed in this work. In order to take into account the uncertainties arising from geometric and physical factors, a non-linear stochastic model based on the discretization of random Karhunen-Loève fields was also evaluated. To verify the accuracy of the deterministic and stochastic numerical-computational model for the nonlinear sandwich beam, an experimental procedure was also carried out inside a thermal camera with strict temperature control. Through the various examples of simulations and experimental tests, the results show that the methodologies proposed in this work were able to represent the influence of operational and environmental conditions on dynamic responses in viscoelastic systems with geometric nonlinearity. It was verified both numerically and experimentally that the non-linear response of the system is influenced by factors such as the excitation force and the operating temperature of the viscoelastic material.