Browsing by Author "Mendes, R."
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- Anatomic region differences and age-related changes on Na+ and K+ levels in human brainPublication . Pinto, Edgar; Ramos, P.; Carvalhido, A.; Pinto, N.; Mendes, R.; Santos, A.; Almeida, A.Neurodegenerative diseases (ND) have been the subject of intensive research in last years in an attempt to understand the mechanisms underlying the neurodegeneration process. The etiology of these diseases is multifactorial, involving a complex interaction between the aging, genetic predisposition and environmental factors. In particular, the role of metals as risk factors for neurodegenerative disorders is currently being studied. As regards to this topic, the knowledge of metal distribution in the brain is of major importance. Evidence suggests that Alzheimer's disease (AD) is associated with impaired depressed Na+/K+ ATPase levels in AD brain that might lead to a cellular ion imbalance. Recent studies show that a pronounced levels in AD brain that might lead to a cellular ion imbalance. Recent studies show that a pronounced and the age of individuals.
- Control optimization of a robotic birdPublication . Couceiro, M. S.; Ferreira, N. M. Fonseca; Mendes, R.; Pires, E. J. Solteiro; Machado, J. A. TenreiroIn this paper it is studied the modeling and control of a robotic bird. The results are positive for the design and construction of flying robots and a new generation of airplanes developed to the similarity of flying animals. Once implemented the dynamic models studied, we will study different movement planning routines and the dynamic stability to adopt, the development of computational simulation based on the dynamic of the robotic bird should allow testing strategies and different kind of control such as integer and fractional controllers. It is studied different kindo of optimization algorithms in order to achieve the best algorithm of control to use in our model. We compare the Gradient Descent optimization method to the PSO algorithm presenting somo time response parameters of our system under the action of different controllers. Firstly, we provide an overview of the system model; secondly, we compare the behaviour of fractional and integer order controllers using different algorithm for the controller optimization in order to obtain the menium error.