It is known that gloss has a significant impact on colour measurement. The UV varnish used for surface finishing, spot effects, as well as special effects, such as 3D effects and formation of Braille, has a pronounced gloss effect. In this work, a comparison of the spectrophotometer measurement geometry influence on the colour measurement of an unprinted PVC sample covered with UV varnish was done. UV varnish was applied successively in layers, and patches with different number of varnish layers, from 1 to 12, were formed. Two spectrophotometers with different measurement geometries were used for the measurement: Konica Minolta CM-2600d with d/8 measurement geometry, with spectral reflection included and excluded, and different measurement aperture 3 and 8 mm, and X-Rite eXact with 45/0 measurement geometry. By comparing the measurements, it was estab-lished that there is a significant difference in the measured values between different measuring device geometries on the given samples, and that the number of UV varnish layers has a significant influence on this differenc

Polymers and polymer composite materials, due to their properties, are becoming increasingly important materials in industry. They are used in a wide range of applications in space and aerospace, aviation, marine and automotive industry, as well as in production of sports equipment, household appliances, medical equipment, etc. They are expected to withstand loads during their lifetime, which requires predicting the reliability of structural elements, i.e. knowledge of material properties. To achieve better properties, polymer materials are reinforced with different percentages of fibre-reinforced materials, including glass fibres. The paper presents the results of experimental determination of the mechanical properties of injection moulded PA6 polymer reinforced with 30% glass fibres, determined by tensile and impact tests.

Abstract Within this paper, the possibility of using advanced LoRa technology in the field of long-range remote control was considered. For testing purposes, a one-way point-to-point LoRa remote control link was implemented based on the LoRa Ra-02 SX1278 transceiver and the corresponding 32-bit Cortex-M3 microcontroller. The remote control application software is developed in the Arduino development environment. The implemented link was tested experimentally to check the range, data transfer speed and link stability. Test results show that LoRa transceiver modules can be used in the field of long-range remote control.

This paper presents a new method that enables automatic channel change in case of intense interference on the active channel of a wireless communication point-to-point link. Channel change algorithms on the master and slave side of the communication link are presented, which enable the automatic selection of a new communication channel from a predefined set of available communication channels. By applying this method, it is possible to maintain a stable communication link in case of intense unpredictable interference on the transmitter or receiver side. The method applies to two-way master-slave communication links, regardless of the frequency spectrum and the number of used communication channels.

Averaging data on the unit sphere S d (also called a unit hypersphere) is a common problem in computer vision, robotics and other fields, with applications ranging from motion planning to DNA modelling. In this paper, we introduce a new method for averaging data represented as points on the unit sphere S d−1 using the d-dimensional generalized Kuramoto model. Our method is verified on a range of benchmark data sets and compared with common data averaging algorithms. Also, we showcase the applicability of this method for solving rotation averaging problem.

Although the technology to automatically score multiple-choice tests has been around for several decades, it is still not as widely available or affordable, especially for paper-based test processing. The main reasons that hinder these processes are the lack of software systems capable of working with contents that are not filled optimally and do not require expensive scanners or other costly equipment. In this study, we present a software system for the automatic reading, storing, and evaluation of scanned assessment sheets. This software system offers a solution that only requires the usual scanned Evaluation Sheets in the form of a not high-resolution image and with the help of specific markers, the system performs reading, storage, and scoring. The user interface is designed to read and display the data from the Evaluation Sheets in detail so that they are very understandable to the user and allow him to quickly spot any errors. The tool has been validated over six years of use and has been continuously improved throughout that period. Thus, this software system achieves a high level of reliability and sensitivity to different levels of the quality of filling out Evaluation Sheets by students.

Computer graphics, robotics, and physics are one of the many domains where interpolation on the unit sphere S n (often called a unit hypersphere or unit n-sphere) plays a crucial role. In this paper, we introduce a novel approach for achieving smooth and precise interpolation on the unit sphere S n−1 using the n-dimensional generalized Kuramoto model. The proposed algorithm finds the shortest and most direct path between two points on that non-Euclidean manifold. Our simulation results demonstrate that it achieves performance comparable to that of a Spherical Linear Interpolation algorithm. Also, the paper proposes the application of our algorithm in the interpolation of rotations that are presented in the form of four-dimensional data.

Uvod: Povećanje koncentracije olova u okolišu posljedica je intenzivne industrijalizacije i urbanizacije. Toksična djelovanja olova zasnivaju se na inhibiciji aktivnosti velikog broja enzima, indukciji oksidativnog stresa i disregulaciji biosinteze proteina. Najčešći put unosa u općoj populaciji je ingestija kontaminirane hrane i vode, dok je inhalatorni put najčešće povezan sa profesionalnom izloženošću u različitim zanimanjima. Cilj istraživanja je evaluirati laboratorijske metode i biomarkere u procjeni izloženosti olovu. Materijal i metode: Za potrebe neeksperimentalnog kvalitativnog istraživanja korišteni su dostupni naučni članci publicirani na engleskom jeziku u relevantnim bazama podataka (MEDLINE i ScienceDirect). Pretraga baza provedena je upotrebom ključnih riječi: „laboratory diagnostics“, „occupational exposure“, „lead“. Rezultati: Najširu primjenu u laboratorijskoj dijagnostici kod procjene profesionalne izloženosti olovu imaju atomska apsorpciona spektrometrija (AAS) kao zlatni standard i induktivno spregnuta plazma sa masenom spektrometrijom, koja se zbog niske granice detekcije opisuje kao senzitivnija metoda u poređenju sa AAS. Koncentracija olova može se odrediti u brojnim biološkim uzorcima, ali se u laboratorijskoj praksi najčešće upotrebljavaju krv i urin. Kao najznačajniji biomarker u praćenju izloženosti koristi se enzim dehidrataza δ-aminolevulinske kiseline (ALAD) u krvi, kojeg karakterizira progresivna inaktivacija olovom i negativna korelacija sa koncentracijom olova. Također, koncentracija delta-aminolevulinske kiseline u urinu (δ-ALA-U) odražava stanje narušene funkcije enzima u biosintezi hema, te se smatra da dodatno određivanje cink protoporfirina u krvi i koproporfirina u urinu značajno doprinose u procjeni poremećaja izazvanih profesionalnom izloženošću olovu. Zaključak: Adekvatno praćenje izloženosti olovu ovisi o dostupnosti i karakteristikama primijenjenih laboratorijskih metoda, te specifičnosti i osjetljivosti biomarkera. Zbog toga, precizno određivanje koncentracije ALAD i δ-ALA-U, uz dodatne biomarkere, postaje imperativ za poboljšanu evaluaciju profesionalne izloženosti i omogućava pravovremeno poduzimanje preventivnih mjera.

Im vorliegenden Beitrag werden im Rahmen einer politolin­guistischen Analyse Twitter als soziale Plattform und die Twi­tter-Aktivität des ehemaligen US-Präsidenten Donald Trump zwischen dem 8. Dezember 2020 und dem 8. Januar 2021 un­tersucht. Im genannten Zeitraum ist die Frequenz von Trump versendeter Tweets mit dem näher rückenden Datum der 59. Präsidentschaftswahl in der USA und danach ständig gestiegen, bis zu dem Tag, an dem Twitter Inc. sein Twitter-Konto sperr­te. Im Korpus von 317 versendeten Tweets werden bestimmte sprachliche Merkmale einer Analyse auf mehreren Ebenen un­terzogen, ausgehend von zwei Annahmen: (1) es gibt sprachli­che Faktoren, die Populismus auf Twitter begünstigen und (2) die Vorstellung von der Politikvermittlung auf Twitter hängt von den Plattformnutzern selbst und ihrem Sprachverhalten ab. Am Beispiel von Trumps Tweets soll der Artikel veranschau­lichen, (i) wie politisch motivierte Themen und Interessen auf Twitter strategisch kommuniziert werden und (ii) dass Trumps Politikvermittlung auf Twitter die Züge eines populistischen Stils aufweist. Die Analyseergebnisse zeigen, dass seiner beson­deren Twitter-Aktivität komplexe Kommunikationsstrategien zugrunde liegen, um die Annahmen über die zu verändernden politischen Verhältnisse und den zu erreichenden Zielzustand zu schaffen.

Abstract The aim of this study is the assessment of sexual behavior and habits of medical and non-medical students in Belgrade. The research is designed as cross-sectional study conducted in the period from November until January 2016/2017. An anonymous and standardized questionnaire from the “National Health Survey” research protocol was used and variables of interest were added. A total of 1268 randomly selected students participated, from higher education institutions in Belgrade (College for Health Studies “Milutin Milankovic, Medical College of applied sciences in Zemun, Belgrade, Business Academy and Faculty of Security Studies in Belgrade). Results: Respondents from both groups almost had sexual relations with the opposite sex, although 2.2% of students of medical profession and 1.7% of nonmedical profession had sexual relations with the same sex. Condoms are most often contraceptive measures used in both groups, (>40%). The most common reason for not using condom in both groups were partner's trust or reducing pleasure during intercourse (p<0.005 and p<0.851 respectively). Students of non-medical professions comparing to students of medical professions, on the second year of study (7.3% vs 5.5%), and on the third year of study (14.1% vs 2.4%) stated that the reason for not using a condom is the high cost. Conclusions: According to the obtained results, students of medical professions were prone to risky sexual behaviour, despite greater knowledge about reproductive health and risky sexual behaviors. There is a significant need for an evaluation of educational programs about sexual and reproductive health of students from all orientations.

Any building, at any time could experience a fire. Because of that, occupants need a fire evacuation path that is designed according to the design standards as they are unable to be entirely prepared for fire emergency scenarios. However, the majority of these standards were developed using empirical judgments. The aim of the paper is to determine whether the fire escape exit route design takes into account the demands and behaviour of building occupants or if it only considers the recommendations and regulations already in place. One university building has been chosen for qualitative research, and as a result, students and teachers are the primary target population. The following factors are taken into consideration throughout the research: the number of students and professors, the movement speed of building occupants and persons with special needs, the plan, the number of floors, the width and length of corridors, the location and type of stairways, as well as type, position and geometry of doors. The findings of this case study indicated that younger occupants can safely exit the building, however older occupants and students with disabilities, as well as teaching personnel need more time for evacuation across the same evacuation paths in fire situation. In this regard, the findings of this research paper offer conclusions that might be useful in design and organization of such and similar buildings and environments.

The paper deals with the phenomenon of non-fungible tokens (NFT), and its particular focus is on the so-called “Art NFTs”, and on the legal demystification of the superior attributes assigned to these tokens. The paper addresses a number of issues. Firstly, it examines the legal and technical possibility to actually create a “digitally unique” piece of author’s work. Secondly, it explores the acquisition of ownership and copyright in the work of art, to which the NFT referres to, during the process of creation and transfer of that NFT. Finally, the paper scrutinizes the topics of copyright violations, which may occur while minting the tokens and of the destruction of the physical original of the tokenized work. The paper also deals with two relevant cases from practice (Miramax, LLC v. Tarantino and Free Comb With Pagoda, J.M. Basquiat), which illustrate how the so-called “Art NFTs” collide with copyright principles.