Systems biotechnology of baculovirus-producing insect cells

Dissertation presented to obtain the Ph.D degree in Ciências da Engenharia e Tecnologia, especialidade Biotecnologia

Natural antioxidants extraction and their incorporation into model pharmaceutical systems

Dissertation to obtain a Master Degree in Biotechnology

Study of forbidden transitions in atomic systems

A Thesis submitted for the co-tutelle degree of Doctor in Physics at Universidade Nova de Lisboa and Université Pierre et Marie Curie

Fatigue life assessment of exhaust systems for naval gas turbines

Dissertação para obtenção do Grau de Mestre em Engenharia Mecânica

Diagnosis in evolvable production systems

Dissertação para obtenção do Grau de Doutor em Engenharia Electrotécnica e Computadores especialidade: Robótica e Manufactura Integrada

Models for pheromone evaluation in Ant Systems for Mobile Ad-hoc networks

On a mobile ad-hoc network environment, where the resources are scarce, the knowledge about the network's link state is essential to optimize the routing procedures. This paper presents a study about different pheromone evaluation models and how they react to possible changes in traffic rate. Observing how the pheromone value on a link changes, it could be possible to identify certain patterns which can indicate the path status. For this study, the behavior of the Ant System evaluation model was compared with a Temporal Active Pheromone model (a biological approach) and a Progressive Pheromone Reduction model with and without a maximum pheromone limit.