Volume 6, Issue 2, 2021.

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 on 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. At present, there are 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

Users, Developers and Managers vs. Traditional and Non-traditional Computing Mechanisms in Automated Software Testing: A Systematic Literature Review

Sara GRAČIĆ, Vuk Vuković

Naftna Industrija Srbije j.s.c. has started the transformation from a focused traditional oil and gas company to a broad energy major. This equally applies to all of its vertically integrated businesses including motor fuel retail business in Serbia. Currently, the company is dominating the Serbian motor fuel retail market due to its crude oil refining facilities, own largest network of stations, strong brands, a wide variety of products and services, and familiarity with customer’s preferences. At the same time, the motor fuel retail market started experiencing pressure created by the threads of product substitutes – non-fossil fuels. Customers are increasingly attached to electric vehicles and hybrid electric vehicles, their number is increasing in the Serbian market. Entry into the electric vehicle charging market in Serbia with charging and battery swapping services would be a new strategic initiative of the company creating potential value for its businesses. This strategic initiative perfectly fits the company’s strategy, helps to fulfill its mission and meets the value proposition “drive more miles, enjoy a drive”. The strategic initiative also secures the competitive advantage of the company consisting of a combination of determinants of relatively low costs and differentiation.