This work aims at developing a fault detection system for photovoltaic systems (PVSs) based on the Fuzzy C-Means (FCM) clustering technique. A simulator is developed based on a mathematical model of the PVS by considering three groups of faults: shading, short circuit, and junction box to investigate the fault effects in photovoltaic systems. Several tests are carried out and indicate that the FCM is able to detect these faults and separate the data of a faulty PVS from that of a healthy one based on uncertain data obtained from different weather conditions.

A verification methodology is described and evaluated to formally determine uncertain linear systems stability in digital controllers with considerations to the implementation aspects. In particular, this methodology is combined with the digital-system verifier (DSVerifier), which is a verification tool that employs Bounded Model Checking based on Satisfiability Modulo Theories to check the stability of digital control systems with uncertainty. DSVerifier determines the control system stability, considering all the plant interval variation set, together with the Finite Word-length (FWL) effects in the digital controller implementation; DSVerifier checks the robust non-fragile stability of a given closed-loop system. The proposed methodology and respective tool are evaluated considering non-fragile control examples from literature. Experimental results show that the approach used in this study is able to foresee fragility problems in robust controllers, which could be overlooked by other existing approaches due to underestimating of FWL effects.

Digital controllers have several advantages with respect to their flexibility and design's simplicity. However, they are subject to problems that are not faced by analog controllers. In particular, these problems are related to the finite word-length implementation that might lead to overflows, limit cycles, and time constraints in fixed-point or floating-point processors. This paper proposes a new method to detect design's errors in fixed-point digital controllers using a state-of-the art bounded model checker based on satisfiability modulo theories. The experiments with a commercial plant demonstrate that the proposed method can be effective in finding errors in digital controllers than other existing approaches, which are based on traditional simulations tools. The verification results are conclusive in 93.5% of the benchmarks, determining the absence or occurrence of errors.

The curricula of engineering courses are well defined by the central government for all Brazilian universities. Indeed, there are some mandatory determinations that must be fulfilled prior to the accreditation of any engineering course in Brazil. Modifications must be submitted for evaluation beforehand, resulting in a process that sometimes takes years to be approved. That is a secure way to guarantee that the fundamentals of each engineering program will be part of the students' carrier all over the country, and at the same time a problem when you need to introduce new technological subjects. That poses a problem when you have new demands for technological curricular components that could express the actual state of the art of modern subjects. Trying to solve these issues some professors from the Federal University of Amazonas developed a flexible extra-curricular program for electrical and computer engineering courses, named Gift Young Engineers. This paper describes the philosophy of these extra-curricular programs. Some examples of successful particular partnerships are also discussed. Indeed the proposed training programs for Digital TV Systems (hardware and software) will be presented and analyzed in details. The obtained results will also be discussed in order to contribute to similar experiences worldwide.