José Luis Díez

Virtual and remote control laboratory development

This work describes Internet functions that include video file generation and real-time control as MWS (MATLAB Web server) features, which are useful for undergraduate courses. With these functions, using virtual processes, which in turn allow video animations of simulated processes, can enhance virtual laboratories. Furthermore, MWS allows the implementation of remote laboratories operating in batch mode. WinCom or any other suitable software can be used to implement online laboratories. These methodologies provide a straightforward approach for the developer of the teaching material, the control engineering lecturer, and a low-cost option for the student user.

A multiple local models approach to accuracy improvement in continuous glucose monitoring.

BACKGROUND Continuous glucose monitoring (CGM) devices estimate plasma glucose (PG) from measurements in compartments alternative to blood. The accuracy of currently available CGM is yet unsatisfactory and may depend on the implemented calibration algorithms, which do not compensate adequately for the differences of glucose dynamics between the compartments. Here we propose and validate an innovative calibration algorithm for the improvement of CGM performance. METHODS CGM data from GlucoDay(®) (A. Menarini, Florence, Italy) and paired reference PG have been obtained from eight subjects without diabetes during eu-, hypo-, and hyperglycemic hyperinsulinemic clamps. A calibration algorithm based on a dynamic global model (GM) of the relationship between PG and CGM in the interstitial space has been obtained. The GM is composed by independent local models (LMs) weighted and added. LMs are defined by a combination of inputs from the CGM and by a validity function, so that each LM represents to a variable extent a different metabolic condition and/or sensor-subject interaction. The inputs best suited for glucose estimation were the sensor current I and glucose estimations Ĝ, at different time instants [I(k), I(k)(-1), Ĝ(k)(-1)] (IIG). In addition to IIG, other inputs have been used to obtain the GM, achieving different configurations of the calibration algorithm. RESULTS Even in its simplest configuration considering only IIG, the new calibration algorithm improved the accuracy of the estimations compared with the manufacturers estimate: mean absolute relative difference (MARD)=10.8±1.5% versus 14.7±5.4%, respectively (P=0.012, by analysis of variance). When additional exogenous signals were considered, the MARD improved further (7.8±2.6%, P<0.05). CONCLUSIONS The LM technique allows for the identification of intercompartmental glucose dynamics. Inclusion of these dynamics into the calibration algorithm improves the accuracy of PG estimations.

A fuzzy clustering algorithm enhancing local model interpretability

In this work, simple modifications on the cost index of particular local-model fuzzy clustering algorithms are proposed in order to improve the readability of the resulting models. The final goal is simultaneously providing local linear models (reasonably close to the plant’s Jacobian) and clustering in the input space so that desirable characteristics (regarding final model accuracy, and convexity and smoothness of the cluster membership functions) are improved with respect to other proposals in literature. Some examples illustrate the proposed approach.

A GLOBAL APPROACH FOR THE REMOTE PROCESS SIMULATION AND CONTROL

Abstract Systems Engineering and Control teaching has a problem in common with other technical studies when distance learning is required: laboratory lectures. It is related to the studied concepts in the area and the requirement of using specific software tools (i.e. Matlab) and process. This paper presents a global approach for the remote process simulation and real control using Matlab Web Server (MWS) tool. This work allows the execution of Matlab developed applications from any remote computer having a Web browser. The server obtains configuration parameters from a Web page and runs M-file Matlab programs. Once the simulation or the real process control has finished, MWS returns the output results to the remote computer through a new Web Page.

Docencia en Automática: Aplicación de las TIC a la realización de actividades prácticas a través de Internet

Este trabajo ha sido realizado parcialmente con fondos de la CICYT mediante contrato DPI2007-61068. El sistema del brazo robotico ha sido realizado en el Grupo de Innovacion Educativa en Automatica de la Universidad de Alicante (GITE-UA) y en el marco del proyecto de investigacion DPI2008-02647.

Remote TCP/IP-based process control with time-varying sampling period

This paper presents a remote process control application trough the Internet, considering the negative effects of TCP/IP-based networks over computer control due to time-varying sampling period. A controller design approach that uses time-varying observers and state feedback controllers designed by means of linear matrix inequalities (LMI) and quadratic Lyapunov functions helps in overcoming the outlined problem. An experimental setup for remote DC motor control shows the applicability of the approach in a real implementation.

Fuzzy clustering algorithm for local model control

Abstract Fuzzy modelling has interpretability of the obtained models as a fundamental goal. In this paper a control-oriented local-model fuzzy clustering algorithm will try that local models approximate the linearized plant model on their validity zones. A family of clustering algorithms is presented so that it incorporates some desirable characteristics regarding convexity and smoothness of the final identified clusters, with advantages regarding other methodologies such as Gustaffson-Kessel. The algorithm simultaneously provides local linear models and input clustering, being suitable for Takagi-Sugeno models and local linear models decomposition of complex systems.

An interactive course on "Logic controllers design using Grafcet"

Abstract The use of Grafcet as a design methodology for logic controllers is increasing, and PLCs manufacturers are including Grafcet as a programming language at its software. However, learning the basics of Grafcet is not an easy task for those not used to Petri Nets but, provided it is a graphic language, multimedia can provide the appropriate framework for a fast and easy learning environment. In this paper, a web-based introductory course on Grafcet basics is presented, whose interactive simulation capabilities are used in automation examples and exercises, then giving to students a closer vision to real process to be automated.

A comparative study of codification techniques for clustering heart disease database

Abstract This paper compares various proposals for codifying categorical attributes in a heart disease database so that numerical clustering algorithms can be applied to them. An approach for the codification of categorical attributes based on polar coordinates is proposed. This is compared with other codifications and methods for clustering mixed databases found in the literature. Our proposal has many advantages: it is relatively easy to understand and apply; the increment in the length of the input matrix is not excessively large; and the committed error is under control. The proposed codification has been combined in this case with the well-known k-means algorithm and has shown a very good performance in a heart disease database benchmark.

Equal opportunities analysis in the university: The gender perspective

The social systems’ complexity is a consequence of the human presence. Measurements and evaluations are rather qualitative and, in many cases, heuristic and / or linguistic. Human beings are not equally treated, with a clear discrimination based on age, gender, race or culture, among many other reasons. Women discrimination is the focus of our study in this paper. The university, as a social system, is investigated. The goal is to determine the degree of gender discrimination and to provide the tools to evaluate different actions to improve the equal opportunity (EO) principle in its operation.