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Abstract
This paper addresses one of the key components in today's industrialization approach: virtualization. The work describes the virtualization of a typical production process, the digital twin in the scope of Industry 4.0, involving different devices, such as robotic arms, conveyors, automatic warehouses and vision systems. It includes both legacy and recent equipment, with different characteristics and communication capabilities, ranging from RS232 serial communication to TCP/IP-based communication, or even I/O-based interaction for devices with no communication capabilities. The developed approach aims at industrial implementations, while allowing for educational purposes. For a standardized approach, the OPC UA protocol is used for high-level communication between the various systems. Several results are described showing the success of the methodology and application.

Abstract
Current trends in the development of remote control devices for user interaction with multimedia equipment and applications are increasingly advancing the traditional keypad-based technologies, in order to improve the functionality of remote control devices and also to enhance the user experience. Haptic feedback allows the user to have a similar sensation to that provided by conventional buttons, with the advantage of a much greater flexibility, including dynamic choice of mechanical effects capable of discriminating between different functions. However, selection of haptic feedback effects that are capable of enhancing the user experience remains a great challenge for engineers and product designers. This work is a contribution towards this goal by presenting a usability study of two technologies (eccentric rotating mass and linear resonant actuator) capable of providing different haptic feedback effects in remote control devices. A subjective evaluation study was carried out to obtain subjective scores for a significant number of haptic feedback effects. The number of preferred actuators of each type and whether haptic feedback is suitable in remote control devices for interactive multimedia, were also evaluated. The results of this study show that most users prefer an interface with haptic feedback and different scores were obtained for different haptic feedback effects, according to the characteristics and number of the actuators.

Abstract
The potentialities of using mobile devices such as smartphones for teaching/learning purposes are huge. However, in some teaching areas its use is still residual. The use of mobile applications in the context of teaching PLC programming techniques is addressed in this work. The MIT App-Inventor II is deployed to develop mobile applications for learning purposes. An android based application entitled Time-Counts is proposed here, developed to support the teaching/learning process of timers. Preliminary results regarding its use by students are presented. © 2019, Springer International Publishing AG, part of Springer Nature.

Abstract
The paper deals with a robust constrained control based on extended state observer (ESO) and state controller design using integral plant models of step-wise increasing complexity. The presented approach is used to enforce and consolidate the student's skills by repeating the state observer and state controller design for several modifications of the plant model. Importance of the control design evaluation by appropriate performance measures is also stressed. Thereby, this approach may help in discovering new interesting properties of this type of control.