Abstract
The use of smart phones for teaching and learning purposes is an increasingly important issue. MIT App-Inventor 2 is presented here as a tool to develop applications for Android mobile systems, with the global aim to improve the connectivity between teachers and students. Two recently developed applications using this technology: Teach2Student and Student2Teach are reported. Teach2Student has two main functions: i) to allow teachers to post their students courses main class's issues; ii) To provide students with specific quizzes. Student2Teach the corresponding students application, is used to visualize the posts and quizzes submitted by teachers. Preliminary results concerning the use of both applications within an industrial automation and control course are presented.

Abstract
Nature and biological inspired search and optimization methods are simple and powerful tools that can be used to design classical industrial controllers. In this paper a particle swarm optimization (PSO) algorithm based technique is deployed to design proportional integrative and derivative controllers to fulfill minimum robustness constraints. PID robustness design using maximum sensitivity and complementary sensitivity values is re-addressed and formulated within a constrained PSO. Results are presented and analyzed regarding the control objective of load disturbance rejection and compared with other techniques.

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Abstract
In this paper we propose the gravitational search algorithm to design PID control structures. The controller design is performed considering the objectives of set-point tracking and disturbance rejection, minimizing the integral of the absolute error criterion. A two-degrees-of-freedom control configuration with a feedforward pre-filter inserted outside the PID feedback loop is used to improve system performance for both design criteria. The pre-filter used is a Posicast controller designed simultaneously with a PID controller. Simulation results are presented which show the proposed technique merit.

Abstract
The refinement of an existing internet multimedia tool to support teaching/learning activities concerning GRAFCET is reported here. The tool called c-GRAFCET resulted in an updated and improved version called e-GRAFCET+. The overall objective of this internet-based tool is to provide fundamental aspects regarding GRAFCET presented with animated examples, promoting students self-learning. While originally this tool was developed to be used by Portuguese speakers, now it is also available in English. The tool upgrading resulted in the elaboration of a new internet portal, incorporating new features, concerning the site management and question quizzes updating. A very important feature of e-GRACFCET+, is to be prepared to work on most devices regardless of operating systems and screen sins, such as smart-phones and tablets.

Abstract
The author's wishes to make the following correction: all the IAE values presented in the paper are multiplied by a factor of 100. The authors would like to apologise for any inconvenience caused. © 2015 Elsevier B.V.