Criticism as a tool for active learning. An example of application in Statistics

Postprint (published version

A proportional controller based on clustering theory: an academic example of a machine learning discipline

The main objective of this paper is to present a controller design based on the K-means clustering theory. The controller is realized in such way that when the plant output is located outside of the designed clustering set, the controller forces it to be in it. Moreover, and according to our real experiment applied to stabilize an unstable integrator plant, our controller approach design is also robust against un-vanishing perturbations and nonlinearity effects on the overall closed-loop system such as saturation, slew-rate limit, and limit bandwidth frequency operation.Postprint (published version

Image fusion based on principal component analysis and slicing image transformation

Image fusion deals with the ability to integrate data from image sensors at different instants when the source information is uncertain. Although there exist many techniques on the subject, in this paper, we develop two originative techniques based on principal component analysis and slicing image transformation to efficiently fuse a small set of noisy images. For instance, in neural data fusion, this approach requires a considerable number of corrupted images to efficiently produce the desired outcome and also requiring a considerable computing time because of the dynamics involved in the fusion data process. In our approaches, the computation time is considerably smaller. This results appealing to increasing feasibility, for instance, in remote sensing or wireless sensor network. Moreover, and according to our numerical experiments, when our methods are compared against the neural data fusion algorithm, they present better performance.Postprint (published version

An experimental platform for statistical fault diagnosis in propelled mechanical systems: an academic exercise

Statistical data analysis for fault diagnosis in mechanical systems is a fundamental tool, for instance, in applied mechanical engineering. In order to capture a feasible data set, a well designed electronic instrumentation and excitation system signal stages are mandatory. Hence, one objective of this paper is to develop a low cost vibration sensor based on an inductive LC-tank oscillator (a resonant inductive-capacitive electronic circuit carefully designed to produce an harmonic electrical signal), and then to tune an effective excitation system signal to our experimental platform. This platform uses a propelled drone motor mounted on a beam structure to emulate a propelled rotating machine. Essentially, two data set were acquired. One for the healthy behaviour of the developed system, and the other for a programmed faulty scenario. This defective case was realized by introducing a small mechanical fault in one blade extreme of the mechanical propelled system. To note, this faulty scenario is almost impossible to deduce by just seen the raw data. The other objective of this paper is to analyze the obtained data sets by utilizing a statistical data analysis tool. Then, by employing box-plot diagrams, the healthy and faulty cases become evidenced. Finally, and due to we are proposing a low-cost academic experimental platform for fault diagnosis based on data analysis, our platform’s toll was around 120 euros. Hence, this platform results applicable to teach data analysis from dynamical systemsPeer ReviewedPostprint (published version

A robust asynchronous sampled-data control design for nonlinear systems with actuator failures

This paper presents a recent self-sampled-data control algorithm applied to nonlinear systems with actuator failures. Our approach uses the linear model of a given nonlinear system, and based on a granted actuator fault observer method, an asynchronous sampled-data fault compensator controller is then formulated. The proposed sampling rule is realized by using an event-detector monitoring signal invention. On this way, the sampled rate is self governed and asynchronous by nature. Hence, our contribution is twofold. Fist, a new auto-generated non-uniform sampled-data mechanism is stated. Second, we grant an event-triggered control law with actuator failure observation and compensation. Our findings are completely supported by employing Lyapunov’s theory. Finally, according to our numerical experiments applied to an undamped torsional pendulum, our design is able to detect a failure in the actuator device and it can stabilize the undamped torsional pendulum system presenting better performance in comparison to its open-loop deployment.Postprint (published version

Future educators' explaning voices

Teacher education programs must offer pre-service students innovative technology-supported learning environments, guiding them in the revision of their preconceptions on literacy and technology. This present paper presents a case study that uses podcast to inquiry into future educators’ views on technology and the digital age. Results show future educators present rather conservative views on technology use and few of them relate to the theme from their future professional identity. Courses aimed at preparing future educators to make pedagogical use of technology should explicitly address students’ preconceptions so as to favor the educational approaches required for the development of the twentieth century skills.Postprint (published version

Image segmentation based on statistical confidence intervals

Image segmentation is defined as a partition realized to an image into homogeneous regions to modify it into something that is more meaningful and softer to examine. Although several segmentation approaches have been proposed recently, in this paper, we develop a new image segmentation method based on the statistical confidence interval tool along with the well-known Otsu algorithm. According to our numerical experiments, our method has a dissimilar performance in comparison to the standard Otsu algorithm to specially process images with speckle noise perturbation. Actually, the effect of the speckle noise entropy is almost filtered out by our algorithm. Furthermore, our approach is validated by employing some image samples.Peer ReviewedPostprint (published version

Matemàtiques per a l’enginyeria a l’Espai Europeu d’Educació Superior: Me4s

Aquest projecte ha permès generar material docent en l’àrea de matemàtiques, basat en l’ús del software matemàtic Maple. S’ha publicat un llibre amb Edicions UPC, titulat Matemáticas para la Ingeniería con Maple, a la col·lecció Temes Clau i s’està confeccionant una web amb l’ajuda de La Factoria UPC. Així, aquest material estarà a l’abast de tota la comunitat universitària, a través de la xarxa. Basant-se en els continguts de les assignatures de matemàtiques de les carreres que imparteix la UPC, s’ha plantejat crear un compendi de sessions d’aprenentatge al laboratori, que es composen d’un resum de teoria, uns tutorials amb Maple i exercicis proposats amb solució. L’equip personal es composa de tres professors doctors que tenen una llarga i dilatada experiència docent en aquesta àrea, impartint i coordinant les assignatures troncals, optatives i de lliure elecció a les quals va dirigit aquest projecte. El material que s’ha creat es basa en les pràctiques que aquests professors venen usant, amb l’objectiu de renovar-les i adaptar-les a l’EEES. La comunitat directe d’impacte està formada per les quatre especialitats que s’imparteixen a l’EUETIB. S’ha fet difusió del material creat sota aquest projectes a dos congressos internacionals i un de nacional, fent un total de quatre comunicacions.Peer Reviewe

Matemàtiques per a l’enginyeria en l’espai europeu d’educació superior

Aquest projecte ha permès generar material docent en l’àrea de matemàtiques, basat en l’ús del software Maple i s’està confeccionant una web amb l’ajuda de La Factoria UPC. Basant-se en els continguts de les assignatures de matemàtiques de les carreres que imparteix la UPC, s’ha plantejat crear un compendi de sessions d’aprenentatge al laboratori, que es composen d’un resum de teoria, uns tutorials amb Maple i exercicis proposats amb solució. El material que s’ha creat es basa en les pràctiques que aquests professors venen usant, amb l’objectiu de renovar-les i adaptar-les a l’EEES.Peer Reviewe

A Proportional digital controller to monitor load variation in wind turbine systems

Monitoring the variation of the loading blades is fundamental due to its importance in the behavior of the wind turbine system. Blade performance can be affected by different loads that alter energy conversion efficiency and cause potential safety hazards. An example of this is icing on the blades. Therefore, the main objective of this work is to propose a proportional digital controller capable of detecting load variations in wind turbine blades together with a fault detection method. An experimental platform is then built to experimentally validate the main contribution of the article. This platform employs an automotive throttle device as a blade system emulator of a wind turbine pitch system. In addition, a statistical fault detection algorithm is established based on the point change methodology. Experimental data support our approach.Peer ReviewedPostprint (published version