Wiktor Olchowik

An education system can be considered as an anthropotechnical system consisting of an education subject (e.g., trainee, operator), examiner (teacher), system decision maker (e.g., teaching module coordinator), and the environment (e.g., administrative, social, IT). The outcomes of this system are the knowledge and skills acquired by a trained student. The educational effect is usually diagnosed in the form of an exam or test. The study addresses the issue related to the credibility of applied assessment methods, knowledge qualification levels, and assessment errors. The analysis is conducted in accordance with the principles applied in statistical quality control when studying product population defectiveness. Using known methods for testing product defectiveness, the authors characterized the trainee educational effect (i.e., his/her knowledge and skill level) in a technical manner. The probability of an event wherein the examined person demonstrating a specific knowledge level achieves an adequate grade, has been adopted as the reliability measure. The conducted calculations provided graphs of the reliability functions involving the grades received within the “traditional” examination and testing process. The authors suggested an application that tests a SCADA system user, based on tools known to the trainee. The application was developed using the SCADA suite used as a visualization element in distributed control systems. This application enables the automation of the operator diagnosis process.

In light of the rapidly growing number of photovoltaic micro-grids, the modelling of their short-term power yields based on meteorological measurements is increasing in significance. This requires the knowledge of total and diffuse instantaneous solar radiation; however, most meteorological stations conduct actinometric measurements only with regard to total solar radiation, especially on a minute scale. This paper contains an analysis of the currently used PV cell mathematical model and suggests its modification aimed at calculating PV cell power with satisfactory accuracy, without the knowledge of diffuse solar radiation. Three function families were proposed to approximate the relationship between diffuse irradiance and the total and theoretical total irradiance variance for a cloudless sky. A program has been implemented to identify functions from the aforementioned function families. It leverages an evolution strategy algorithm and a fitness function based on the least-squares point method. It was employed to calculate the desired functions based on actual measurement data. The outcome was the sought-after dependence that enables predicting diffuse irradiance based on more frequently available measurement data.