University of Niš: Facta Universitatis (E-Journals) / Универзитет у Нишу
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INNOVATIVE DESIGN STRATEGY FOR AN INTERNAL COMBUSTION ENGINE WITH IMPROVED OUTPUT CHARACTERISTICS
Full text linkThe paper describes the concept of a new internal combustion engine. Presented IC engine concept possesses a variable displacement, variable compression ratio, combustion at constant volume, improved intake and exhaust processes, as well as more complete expansion of the working fluid. A comparison of some performance of this new concept with conventional IC engine and electric motors is provided. The results indicate that the performance of IC engine can still be improved. The achieved efficiency of the engine is over 40%. The Ricardo Wave program was used for simulating the characteristics of the engine. CAD model of concept engine was made with CATIA V5
UTICAJ DNEVNIH VARIJACIJA NA DEFICIT U PROMENI PRAVCA KRETANJA I LINEARNOM DRIBLINGU KOD RUKOMETAŠA
No full textThe present study aims to determine the effect of time-of-day on linear and change‑of‑direction Dribble Deficit in elite male handball players. Sixteen elite male handball players from a Serbian Super League club participated in this study (mean ± SD: age 25.4 ± 5.8 years, body mass 94.0 ± 7.4 kg, stature 193.5 ± 7.5 cm). All participants completed four physical performance tests without a ball (change-of direction Zig-Zag test, 5-m, 10-m and 20-m linear sprints) and four tests with a ball (change-of direction Zig-Zag and 5-m, 10-m and 20-m linear sprints) at two separate testing sessions in the morning (8:00-9:30am) and in the evening (6:00-197:30pm). Dribble Deficit parameters for change-of-direction and linear sprint did not differ significantly between the morning and evening sessions (p = 0.309–0.757). To conclude, in elite male handball players, the Dribble Deficit for both change‑of‑direction and linear sprint tasks remains almost unchanged from early morning to early evening which is important for coaches to organize training sessions.Ova studija je utvrđivala uticaj doba dana na pravolinijski sprint i promenu pravca kretanja elitnih rukometaša. Šesnaest elitnih rukometaša koji nastupaju u Superligi Srbije su učestvovali u ovoj studiji (mean ± SD: uzrast 25.4 ± 5.8 godina, telesna masa 94.0 ± 7.4 kg, visina 193.5 ± 7.5 cm). Svi ispitanici su uradili po četiri testa motoričkih sposobnosti s ai bez lopte (promena pravca kretanja zig-zag, 5m, 10m, 20m pravolinijski sprint) u dva vremenska intervala, jutarnji (8:00-9:30 h) i večernji (18:00-19:30 h). Dribling deficit za promenu pravca kretanja i linearni sprint se statistički značajno ne razlikuju prepodne i uveče (p = 0.309–0.757). Kod elitnih rukometaša dribling deficit za promenu pravca kretanja i pravolinijski sprint ostaju nepromenjenji od ranog jutra do večeri što je važno za trenere u organizaciji treninga
A MODIFIED FMEA APPROACH BASED INTEGRATED DECISION FRAMEWORK FOR OVERCOMING THE PROBLEMS OF SUDDEN FAILURE AND ACCIDENTAL HAZARDS IN TURBINE AND ALTERNATOR UNIT
Full text linkThe proposed work presents a novel integrated decision framework, based on Intuitionistic Fuzzy (IF)- Failure Mode & Effect Analysis (IF-FMEA), and IF-Technique for Order of Preference by Similarity to Ideal Solution (IF-TOPSIS) approaches for analysing the failure risk issues of Turbine and Alternator Unit (TAU) in a chemical treatment-based sugar process industry. The proposed novel IF-FMEA approach-based modelling overcomes the various demerits of traditional FMEA approaches which are faced during the identification of critical failure causes based on Risk Priority Number (RPN) outputs. On the basis of detailed qualitative information related to plant operation, FMEA sheet was developed and linguistic ratings were collected against three risk factors such as probability of Occurrence (O), Severity (S), and Detection (D). IF- Hybrid Weighted Euclidean Distance (IFHWED) score has been computed to rank all listed failure causes under three risk factors. The ranking results based on IF-FMEA approach has been compared with the well existed IF-TOPSIS approach for evaluating the accuracy of proposed modelling results. Sensitivity analysis has been also done for checking the robustness of the framework. The analysis results were provided to maintenance executives of the TAU unit to frame optimum maintenance plan for overcoming the problems of sudden breakdown. The analysis results are also applicable to TAU systems which are installed in other chemical process industries globally.
ASSESSING PUBLIC ACCEPTANCE OF AUTONOMOUS VEHICLES USING A NOVEL IRN PIPRECIA - IRN AROMAN MODEL
Full text linkAutonomous vehicles (AVs) have become a tangible presence on roads, indicating the emergence of a promising transportation technology for the future, possibly arriving sooner than anticipated. Nevertheless, the extensive integration of this technology is contingent on various factors, with the foremost being the level of public acceptance and adjustment to this advanced technology. Several factors, including safety, privacy, and cost, play crucial roles in fostering acceptance. Consequently, this research delves into the key determinants shaping individuals' willingness to embrace AVs. In this paper, a novel model, which consists of two methods: PIPRECIA and AROMAN with Interval Rough Numbers (IRNs) has been developed. The IRN PIPRECIA serves to define criterion weights, while the most significant contribution of the paper is the extension of the AROMAN method with IRNs for evaluating the public acceptance of autonomous vehicles and adapting all the necessary conditions for their use. The results show that a rapid implementation with extensive testing strategy represents the best solution
ANALYSIS OF THE MECHANICAL CHARACTERISTICS OF DATE SEED POWDER-BASED COMPOSITE CARBON FIBER REINFORCED POLYMERS
Full text linkComposites with fiber reinforcement are often a popular lightweight option. Due to their unique qualities, fiber-reinforced composites are the best alternative to traditional materials. Mechanical parameters of a carbon fiber-reinforced epoxy resin (CFRE) composite reinforced with date seed granulated powder (DSGP) were examined at the room temperature. The mechanical qualities included tensile, flexural, and impact strength. Enhanced mechanical properties were noticed compared to carbon fiber reinforced epoxy composite produced using the hand lay-up method and vacuum bag. The DSGP-reinforced CFRE with weight ratios of 0%, 15%, 25%, and 35% were considered. The test results revealed the maximum values of breaking force, maximum bending force, energy absorption capacity, and hardness number for 15%, 35%, 25%, 25% Wt DSGP samples. The results show that the optimal composition for carbon fiber reinforced epoxy with date seed granules is in the range from 15% to 25% wt. GDS. This study reveals that carbon fiber-date seed-reinforced composites are excellent substitutes for carbon fiber composites since they offer better mechanical properties at a lower cost
UTICAJ MEĐUNARODNE MIGRACIJE NA EKONOMSKI RAST AUSTRALIJE
No full textThis study examines the role of migration in the growth of the Australian economy, using annual data from 1990 to 2021. The study aims to determine whether migration has a positive or negative impact on economic growth in Australia, as the country continues to open its economy to immigrants. The impact of immigration on host economies has been associated with conflicting results when subjected to empirical testing. Australia is among the developed countries that have opened its economy to immigrants in pre-determined sectors and quotas tailored to meet the country’s skills needs. The study would play a key role in guiding policy makers in Australia on migration policies that complement economic growth agenda in the country. The study employs the ARDL to investigate the nature of this relationship. The findings of the study confirm that migration positively influences economic growth only in the short run. The findings of the study suggest that the Australian government's support of immigration indeed positively influences growth in the short run; however, other policies are required to support growth in the long run.Ovaj rad ispituje ulogu migracije u rastu australijske ekonomije, koristeći godišnje podatke od 1990 do 2021. Rad ima za cilj da odredi da li migracija ima pozitivan ili negativan uticaj na ekonomski rast u Australiji, s obzirom na to da zemlja nastavlja da otvara svoju ekonomiju ka imigrantima. Uticaj imigracije na ekonomije domaćina daje protivrečne rezultate kada se podvrgne empirijskom testiranju. Australija je među razvijenim zemljama koje su otvorile svoju ekonomiju za imigrante u unapred određenim sektorima i kvotama prilagođenim potrebama zemlje za veštinama. Studija bi mogla da igra ključnu ulogu u vođenju kreatora politike u Australiji o migracionim politikama koje dopunjuju agendu ekonomskog rasta u zemlji. Studija koristi ARDL da bi istražila prirodu ovog odnosa. Rezultati studije potvrđuju da migracije pozitivno utiču na ekonomski rast samo na kraći rok. Rezultati studije sugerišu da podrška australijske vlade imigraciji zaista pozitivno utiče na rast na kraći rok; međutim, potrebne su druge politike da bi se podržao rast na duži rok
SKLONOST REVIZORA KA IZDAVANJU MIŠLJENJA O STALNOSTI POSLOVANJA: PODACI SA SRPSKOG TRŽIŠTA KAPITALA
No full textThis study investigates possible going concern issues in listed companies in the foreseeable future by analyzing the opinions presented in auditors’ reports covering the period 2021-2023. We use descriptive analysis to conclude that auditor reporting on going concern in the Republic of Serbia is below the level typical for developed economies. The dominant share of other audit firms, those outside the Big 4 group, and consequently the fear of legal costs and loss of reputation may be the reasons why auditors in most cases do not modify their going concern opinions. We analyze all paragraphs of the auditor’s report in which auditors point to the circumstances that caused the crisis in companies, and find that the most frequently mentioned indicators are net loss, accumulated loss and over-indebtedness. Furthermore, we include modified audit opinions based on other key issues in financial statements in the analysis, and conclude that the share of modifications is significantly above the average in developed economies. In this way, we further shed light on financial reporting in the Republic of Serbia and confirm that efforts to improve it are yet to come.Ova studija istražuje prisutnost pitanja vezanih za nastavak poslovanja listiranih kompanija u doglednoj budućnosti putem analize mišljenja iskazanih u revizorskim izveštajima za period 2021-2023. Koristeći deskriptivnu analizu, zaključili smo da je izveštavanje revizora o stalnosti poslovanja u Republici Srbiji ispod nivoa karakterističnog za razvijene ekonomije. Dominantno učešće ostalih revizorskih firmi, koje ne pripadaju „Velikoj četvorci“, i posledično strah od sudskih troškova i gubitka reputacije mogu biti razlozi zbog kojih revizori u najvećem broju slučajeva nisu modifikovali mišljenje po pitanju stalnosti poslovanja. Analizom sadržaja svih pasusa revizorskog izveštaja u kojima revizori navode okolnosti koje su izazvale krizu u poslovanju kompanija, otkrili smo da se kao najučestaliji indikatori pominju neto gubitak, akumulirani gubitak i prezaduženost. Šireći analizu na modifikovana mišljenja revizora koja su zasnovana na drugim ključnim pitanjima u finansijskim izveštajima, zaključili smo da je udeo modifikacija značajno iznad proseka u razvijenim ekonomijama. Time smo dodatno rasvetlili stanje u praksi finansijskog izveštavanja u Republici Srbiji i potvrdili da napori ka njenom unapređenju tek predstoje
PRAVNI SUBJEKTIVITET ZA UMJETNU INTELIGENCIJU: NUŽAN KORAK ILI OPASAN PUT?
No full textIIn its Resolution of 16 February 2017 with recommendations to the Commission on Civil Law Rules on Robotics, the European Parliament calls on the European Commission to consider granting a special legal status to robots, under which the most advanced autonomous robots would be recognized as electronic persons liable for any damage caused by their operations. In this regard, the paper examines the main characteristics of Artificial Intelligence (AI), such as autonomy, opacity, unpredictability and complexity, which can cause problems in the attribution of liability. The paper analyzes whether there are valid reasons for granting (electronic) personhood to the most sophisticated forms of AI. In addition, it examines whether alternative mechanisms, such as the broader application of strict liability, the presumption of fault or causation, no-fault systems, or compulsory insurance, may be used to strike a fair balance between the interests of manufacturers and users of AI systems, as well as third parties.Europski je parlament u Rezoluciji od 16. februara 2017. s preporukama Komisiji o pravilima građanskog prava o robotici pozvao Europsku komisiju u t. 59. f.) da razmotri stvaranje posebnog dugoročnog pravnog statusa za robote kako bi barem najsofisticiraniji autonomni roboti mogli imati status elektroničkih osoba s odgovornošću ispravljanja štete koju su uzrokovali. U tom kontekstu, u radu se razmatraju temeljne karakteristike umjetne inteligencije (UI) poput neprozirnosti, nepredvidivosti i složenosti UI, te njezinog autonomnog djelovanja. U radu se razmatra postoje li opravdani razlozi za priznanje elektroničkog subjektiviteta najsofisticirajnijim oblicima umjetne inteligencije, te da li bi inteligentnim robotima trebalo priznati osobnost u okviru već postojećih pravnih subjekata. Razmatra se i da li postoje neki drugi mehanizmi poput širenja primjene objektivne odgovornosti, kriterija presumirane krivnje te pravila o presumiranoj uzročnosti temeljem kojih bi se uspostavila pravična ravnoteža između interesa proizvođača i korisnika UI sustava, odnosno trećih osoba
NACIONALNE MANJINE U EVROPI I SLUČAJ GRČKE: DA LI MAKEDONSKA MANJINA IMA PRAVA U HELENSKOJ REPUBLICI?
No full textIn the 20th century, most European nations formed their national states. Yet, given the fact that Europe is populated by many ethnicities, there is no national state that does not include an ethnic or religious minority within its territory. The development of human right guarantees at the global and European levels has contributed to the development of minority rights and their guarantees. Many legal documents in Europe guarantee the fundamental rights of minorities but the most important legal act is the Council of Europe’s Framework Convention for the Protection of National Minorities (1995). Despite being one of the most developed countries in South-eastern Europe and ratifying the CoE Framework Convention and other human rights legal documents, Greece has a hostile approach towards national minorities, especially towards the Macedonian ethnical minority. The first part of the paper analyzes the rights of national minorities in European legal documents: the CoE Framework Convention and the European Convention on Human Rights (1950), and their significance for minority rights. The analysis also covers the position of minority rights in the law of the European Union. The second part of the paper focuses on the position and rights of the Macedonian national minority in Greece. While the reviewed legal documents show the European organizations’ commitments to guaranteeing minority rights, the research in this paper proves the Greek state’s violation of minority rights and, particularly, its antagonistic approach towards Macedonian minority rights.U prošlom veku većina evropskih naroda formirala je svoje nacionalne države. Međutim, znajući da je Evropa naseljena mnogim etničkim grupama, ne postoji nacionalna država koja ne uključuje etničku ili versku manjinu na svojoj teritoriji. Razvojem ljudskih prava i njihovim garantovanjem na globalnom i evropskom nivou razvijala su se i manjinska prava i njihovo garantovanje. Mnogi pravni dokumenti u Evropi garantuju osnovna prava manjina, a najvažniji pravni akt je Okvirna konvencija Saveta Evrope za zaštitu nacionalnih manjina. Grčka, uprkos tome što je jedna od najrazvijenijih zemalja u Jugoistočnoj Evropi, i uprkos ratifikaciji Okvirne konvencije i drugih pravnih dokumenata o ljudskim pravima, ima neprijateljski pristup prema nacionalnim manjinama, posebno prema makedonskoj etničkoj manjini. U ovom radu biće urađena analiza prava nacionalnih manjina u evropskim pravnim dokumentima. Analiziraće se Okvirna konvencija Saveta Evrope i Evropska konvencija za ljudska prava i njen značaj za manjinska prava. Takođe, biće sprovedena analiza položaja manjinskih prava u pravu Evropske unije. Potom će se razmotriti položaj makedonske nacionalne manjine u Grčkoj i njena prava. Ovaj rad pokazuje posvećenost evropskih organizacija garantovanju prava manjina. Ali, s druge strane, ovaj rad dokazuje kršenje manjinskih prava od strane grčke države, a posebno njenog antagonističkog odnosa prema pravima makedonske manjine
