Daniel Coutinho

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This paper reports a comprehensive experimental study regarding the human competitiveness of search based software engineering (SBSE). The experiments were performed over four well-known SBSE problem formulations: next release problem, multi-objective next release problem, workgroup formation problem and the multi-objective test case selection problem. For(More)
The Software Requirements phase has notable importance, since it is responsible for the definition of the system itself. Several customers indicate which functionalities they want to be present in the software. However, constraints, such as budget, make it impossible to implement all desired requirements at once. One activity in this context is the release(More)
I T is well-established that numerous problems in control systems involve the use of positive polynomials, i.e., multi-variate polynomials that take only positive values over a domain of interest. Indeed, constraint satisfaction is equivalent to the positivity of a suitable function, as well as performance computation amounts to determining the best(More)
In this study, a multivariable control structure is developed to simultaneously control the concentrations of cells and of one of the nutrients in an animal cell cultivation system operated in perfusion. A cascade control structure is considered consisting of (i) an inner loop with a partially linearizing feedback controller, tuned so as to ensure(More)
This paper intends to demonstrate the development of an easy-to-use local human-machine interface that would allow any user to control distinct types of service robots, intuitively. This interface is based on the Nintedo Wii remote controller and consists of three operating modes: a steering wheel, an infra-red monitor and a movement identifier. These modes(More)
This paper presents an effective and robust structure for the estimation and control of perfusion cell cultures, in which the cells and glucose concentrations are simultaneously controlled by manipulating the dilution and bleed rates. Firstly, a partially linearizing feedback controller is designed to ensure an approximately linear decoupled dynamics(More)
This paper presents a multivariable robust control structure for perfusion animal cell cultures. The control structure assumes a cascade form, where a linearizing feedback controller is used in the inner loop and linear controllers are used in the outer loops, to simultaneously control the cells concentration and the glucose concentration in the bioreactor.(More)