IMPLEMENTATION OF LEBESGUE SAMPLING METHOD AND DIGITAL SENSORS FOR CONTROLLING THE LEVEL VARIABLE IN A CONTINUOUS SYSTEM

This study aims to show that the continuous control from a level system can be efficiently measured and controlled using capacitive digital binary sensors, which in this case, replace the measurement signal from an analog differential pressure transmitter in a level control system. The binary sensors low cost and the digital output they process allow the reproduction of a correct signal and the estimation of a variable for controlling the water level inside the process tank through a proportional pneumatic level control valve, which receives the control signal from the Lebesgue sampling estimation algorithm applied herein for processing digital measurements. In this particular case, the Lebesgue algorithm is applied to reproduce the estimation of values obtained from the continuous signal in the real level process for the measurement and control. Also, are compared both, simulated and real outputs obtained using the Lebesgue algorithm and digital sensors, which were applied to a state observer controller that relates digital signals for controlling the real level system output. The application of the Lebesgue algorithm in the real level process concludes that the analog level signal can be efficiently reproduced using this method. In addition, the controller enables the system to smoothly conduct digital output processing using digital sensors to control the system output correctly, validating that not only analog sensors should be applied for controlling the output of proportional actuators, because it is shown that digital binary signals can be used for controlling and emulating continuous signals, which were processed and applied to the pneumatic valve. Keywords: Lebesgue sampling, estimation, binary sensor, observer controller, finite state machine, continuous system, control, LTI systems, identification, state variable, estimated output, proportional actuator

HEURISTICS FOR AWARENESS SUPPORT IN GROUPWARE SYSTEMS

ABSTRACT: Groupware Systems (GS) or collaborative systems are software systems that support the development of activities in which a group of users interacts to combine their skills, abilities, and work to achieve a common goal. In this area, an important concept is awareness, which is the information that helps people be aware of events beyond their current tasks. This information makes smoother the use of a collaborative system, so it is a fundamental element in this kind of software. In the design and construction of these types of systems, heuristics are used as design guidelines that serve as a useful evaluation tool for product designers and usability professionals. The current heuristics and guidelines for the design of awareness support focus on supporting the awareness of the team in the shared workspace, without considering elements to support the information needs of the user's own and individual interaction within the workspace. To address this problem and to facilitate the design and integration of awareness support, we developed 13 heuristics that integrate principles of Human-Computer Interaction and Computer Supported Cooperative Work to help groupware designers meet individual and team awareness needs. For evaluating the validity of the proposed heuristics, a structured and iterative consultation process was carried out with experts in Human-Computer Interaction and Computer-Supported Cooperative Work. The proposed heuristics can help software engineers develop collaborative systems that integrate awareness information and satisfy users' contextual information needs. Keywords: Awareness, virtual groups, collaborative work, heuristics.

EVALUATING USER EXPERIENCE WITH PHYSIOLOGICAL MONITORING: A SYSTEMATIC LITERATURE REVIEW

ABSTRACT: User Experience (UX) is a key factor and an opportunity for improvement in digital interfaces. Traditionally, it has been evaluated retrospectively through surveys and interviews. However, this is not always the optimal approach, as it does not measure UX at the moment of human-machine interaction and is therefore prone to human error due to inaccurate recall. Thus, physiological monitoring is emerging as a promising technique to assess UX during interactions. This paper aims to identify UX case studies carried out with physiological monitoring by means of a Systematic Literature Review (SLR). The results of the 33 UX case studies reviewed show that interest in incorporating physiological technologies in UX studies is growing and expanding into different fields. The electroencephalogram (EEG) was found to be the most used physiological tool, and the most used set of tools was the Galvanic Skin Response (GSR) with the electrocardiogram (ECG). In addition, the average number of participants was obtained depending on the physiological tool used. The research opportunities identified are: 1) the combination of different methods and tools in the assessment of UX, and 2), the validation of a sample size for UX tests performed with physiological monitoring Keywords: User Experience (UX), evaluation, Systematic Literature Review (SLR), physiological monitorization