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 lower limb prosthesis, as the specific object of this biomechanical research, has the task of restoring the normal function of the missing part of the human body. Creating a prosthesis exclusively for the end user is a very complex process. The subject of analysis in this work is the analysis of forces, deformations and stress state on the example of structural elements of the lower prosthetic device with the aim of understanding the integrity of the structure under the action of variable load. This analysis is one of the bases for the overall approach to the design of prosthetic aids for the end user, and especially the creation of the socket, as the most important element of a prosthesis in contact with man’s residuum. The main goal of this work is to estimate the real value of the load of a complex prosthesis, to understand the effect of the load on the elements of the observed example of construction, and to understand the load transfer on the connection of the prosthesis structure with the socket. After defining the real load values, the performed numerical analysis indicated the critical points of the construction, the need to use more accurate material properties in the “foot” element, and in the “socket” zone, the possibility for corrections of the shape and thickness of the wall.

The unification of quantum mechanics and general relativity has long been elusive. Only recently have empirical predictions of various possible theories of quantum gravity been put to test, where a clear signal of quantum properties of gravity is still missing. The dawn of multi-messenger high-energy astrophysics has been tremendously beneficial, as it allows us to study particles with much higher energies and travelling much longer distances than possible in terrestrial experiments, but more progress is needed on several fronts. A thorough appraisal of current strategies and experimental frameworks, regarding quantum gravity phenomenology, is provided here. Our aim is twofold: a description of tentative multimessenger explorations, plus a focus on future detection experiments. As the outlook of the network of researchers that formed through the COST Action CA18108 ‘Quantum gravity phenomenology in the multi-messenger approach (QG-MM)’, in this work we give an overview of the desiderata that future theoretical frameworks, observational facilities, and data-sharing policies should satisfy in order to advance the cause of quantum gravity phenomenology.

The goal of this work is to design a high-efficiency photovoltaic system (PV) with a fuzzy logic controller. This PV system consists of a PV panel, DC/DC Buck-Boost converter with a 24V DC load, and a fuzzy logic controller. Because the efficiency of normal solar PV modules is very low, we implemented the fuzzy logic controller. In this paper, we have proposed a system that is designed and simulated in MATLAB Simulink. In the fourth section of the paper are shown obtained results which show that using the fuzzy logic controller for photovoltaic systems has better performance. This controller can facilitate the PV array to reach the MPPT faster and provide more stable output power.

The surveillance system has been utilized over the years on public property in order to provide security and prevent unauthorized entrance. Lately, more private homeowners are choosing to implement security systems. There are many problems with the video surveillance system. These disadvantages are the indistinctiveness of the pictures/video and the need for a lot of storage space to save surveillance information. This paper describes the design and implementation of a low-cost Web Monitoring System based on Raspberry Pi. Also, a web application is designed for the purposes of controlling the camera and for live streaming. The live stream from a web camera can be viewed from any web browser, even mobile, in real-time. Controlling the camera is possible with the web application using four commands (up/down, left/right). Also, the camera moves depending on the detection of an object located in the visible area of the PIR Motion sensor, thereby issuing a warning message about object detection.

Bilateral teleoperation has attracted significant research and application interests in a wide range of areas. The first and main use for bilateral teleoperation was to handle the dangerous and remote distance tasks such as space exploration and nuclear materials manipulation. In the past few years, bilateral teleoperation has found its way into other applications as a result of the development of control technologies and the latest breakthrough in artificial intelligence and machine learning. In this paper, the goal is to model bilateral teleoperation for direct control, PID control, and Fuzzy Logic control for the water tank system. The goal is to create a simulation for master-slave communication where the time delay is minimized to the optimal and accepted values. The experimental results obtained from the simulation show a fairly high accuracy in terms of all three ways of control modes, which highlights the effectiveness of the proposed system in the paper.

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.