Application of Watermark in the Form of QR Code in COVID Certificate Validation
Zoran VELIČKOVIĆ, Slađana VELIČKOVIĆ, Zoran MILIVOJEVIĆ
This paper presents the original concept of online verification of CVC certificates. A QR code for online verification is inserted into the holder’s photo. The issuer of the CVC certificate generates a QR code which, among other things, contains the address of a Web service that can be used to check online the validity of the certificate. The presented concept enables the simultaneous connection of the identity of the holder and his certificate. The results of the experiment confirm that the presented concept can be successfully used in the online verification of CVC certificates.
Influence of the Resolver Position Estimation Error on the PMSM Vector Controlled Drive Performance
Vladimir POPOVIĆ, Petar MATIĆ, Darko MARČETIĆ
In this paper, the influence of magnetic analogue encoder (resolver) error to the performance of the vector controlled permanent magnet synchronous motor drive is investigated. Firstly, different imperfections in the resolver quadrature output signals (magnitude mismatch, phase and dc offset and high order harmonics) are properly modeled. Secondly, the influence of resolver quadrature signals imperfections to the estimated rotor angle waveform and consequent motor torque pulsations are modeled and properly analyzed. Characteristic torque signal waveforms are obtained for two typical motor drive field oriented control strategies. As a result, the automatic resolver signals error compensation performed online, or with some kind of self-commissioning mechanism, is recommended.
Comparative Analysis of Methodologies For Flat Foot Parameter Determination
Amira ŠERIFOVIĆ TRBALIĆ, Jakub OSMIĆ, Nerdina MEHINOVIĆ, Nedim JUNUZOVIĆ
Flat foot represents a foot deformation where the arches on the inside of the feet are flattened allowing the entire soles of the feet to touch the floor when a person is standing. The flat feet pathology is normally detected by human experts based on the footprint images, but the lack of trained experts preludes the massive routine diagnostic of this pathology among the population. In present, there are the main two groups of approaches to capture and estimate arch-foot parameters: Vision Based Measurement (VBM) approaches and Foot Plantar Pressure (FPP) measurement and processing. The main characteristics of both approaches will be analyzed and compared in this paper.
Sara GRAČIĆ, Vuk VUKOVIĆ
Testing is important in producing high quality software and can be done manually and/or automatically. Automation has the potential to reduce testing effort (e.g. in developing test cases, generating test data) and speed up testing cycles. This paper aims to present the state-of-the-art achievements in automated testing through its diverse application in practice and investigate how users, developers and managers are influenced by this phenomenon. Five scientific databases were chosen and the search resulted in 52 final papers. Majority of sources proposed traditional testing techniques, while one proposed chemical reaction networks. Although automation is present in developing mobile apps, embedded systems, the automotive industry, etc., most developers do not properly automate testing. Two sources marked user reviews as important. It was also found that managers were drawn to automated software testing because of its potential savings in time, effort and money.