Students' opinions on online classes of English: Possibilities and limitations

Predmet rada je percepcija onlajn nastave engleskog jezika na univerzitetskom nivou iz ugla studenata/kinja koji su ovaj vid nastave pohađali na Poljoprivrednom fakultetu Univerziteta u Beogradu u prolećnom semestru 2020. godine, tokom proglašenog vanrednog stanja zbog epidemije kovida 19. U istraživanju je učestvovalo 40 ispitanika/ca. Ekstenzivnim, onlajn upitnikom koji je konstruisan za potrebe ove studije, ispitivana su mišljenja studenata o raznim aspektima realizovane onlajn nastave i način na koji procenjuju značaj tehničkih, kontekstualnih i psiholoških faktora u tom procesu, kao i motivisanost za učešće u ovom obliku nastave. Rezultati analize pokazuju da su ispitanici/e ispoljili/e visok nivo motivisanosti za ovaj vid nastave engleskog jezika. Ocena praktično svih analiziranih aspekata onlajn nastave je preovlađujuće pozitivna, što se odnosi i na opaženu ekvivalentnost znanja stečenog na klasičnim i na onlajn časovima, kao i na podjednaku interaktivnost jednog i drugog vida nastave. Kao glavnu dobru stvar onlajn nastave većina ispitanika/ca navodi činjenicu da su nastavu mogli da prate od kuće čime su uštedeli na vremenu, kao i olakšanu komunikaciju i atmosferu koja se stvara na onlajn časovima jezika. Kao najčešća loša strana ovog vida nastave navedene su zamerke tehničke prirode, poput loše internet veze i sa njom povezanih prekida zvuka i slike. U zaključnom delu diskutovan je značaj dobijenih rezultata u kontekstu njihovih pedagoških implikacija i potencijala za unapređenje ovakvog vida nastave.Online classes are not a brand-new concept in teaching languages. The use of Internet and different applications and platforms in everyday life all probably contributed to recognizing online classes as a convenient way for language teaching. There has been a plethora of research on online classes, their benefits and weaknesses, as well as on students' attitudes towards this type of learning. Since there are many benefits of integrating online materials into language teaching programmes, some language practitioners are eager to use these regularly, whereas some still hesitate and use this type of teaching rarely or not at all. However, the year 2020 forced all university teachers to conduct online classes due to the COVID-19 pandemic, since it was impossible to conduct face-to-face instruction in classroom setting. This opened up new possibilities, but brought about various problems as well. Having all this in mind, this paper aims to show how university students perceived the online classes of English during the declared national state of emergency in Serbia. These particular students attended online English classes at the Faculty of Agriculture, University of Belgrade, in the spring semester of 2020. An extensive, online questionnaire designed for the purposes of the study was used to examine students' opinions on various aspects of online classes, their assessment of important technical, contextual, and psychological factors in the process, as well as their motivation to participate in online classes. The results of the analysis show that the respondents were highly motivated for this type of English language classes. They predominantly positively assessed practically all analyzed aspects of online classes, including the observed equivalence of knowledge acquired in face-to-face and online classes, as well as the equal interactivity of both types of classes. The level of self-assessed digital literacy of respondents was fairly high, which must have helped students to a great extent in successively attending the classes. As for the main advantage of online classes, most respondents stated that they were able to attend classes from home, which saved their time and facilitated communication. They also liked the atmosphere in online language classes. The most commonly stated disadvantage of this type of classes is poor internet connection, followed by the related interruptions of sound and video. The dominant attitude of the respondents was that English classes at the university should be conducted as hybrid courses, which implies that they should be a combination of face-to-face teaching and online classes. Although small-scale, the findings of this pilot research can help pinpoint the weaknesses of online classes, as well as offer useful suggestions aimed at improving them in the future. For instance, since students mostly use their mobile phones to attend online classes, it would be convenient for the class activities to be accessible and manageable through different social media apps. Still, it may be argued that the findings are limited in scope since the study was conducted on the sample of students of only one faculty of the University of Belgrade; additionally, it explored the experience with only one online course these students attended. Therefore, the research may be expanded by exploring the potential of online classes in different subject courses, as well as at other faculties

Broken seniority symmetry in the semimagic proton mid-shell nucleus ⁹⁵Rh

Lifetime measurements of low-lying excited states in the semimagic ( N = 50 ) nucleus 95Rh have been performed by means of the fast-timing technique. The experiment was carried out using γ -ray detector arrays consisting of LaBr3(Ce) scintillators and germanium detectors integrated into the DESPEC experimental setup commissioned for the Facility for Antiproton and Ion Research (FAIR) Phase-0, Darmstadt, Germany. The excited states in 95Rh were populated primarily via the β decays of 95Pd nuclei, produced in the projectile fragmentation of a 850 MeV/nucleon 124Xe beam impinging on a 4 g / cm2 9Be target. The deduced electromagnetic E2 transition strengths for the γ -ray cascade within the multiplet structure depopulating from the isomeric Iπ = 21 / 2+ state are found to exhibit strong deviations from predictions of standard shell model calculations which feature approximately conserved seniority symmetry. In particular, the observation of a strongly suppressed E2 strength for the 13 / 2+ → 9 / 2+ ground state transition cannot be explained by calculations employing standard interactions. This remarkable result may require revision of the nucleon-nucleon interactions employed in state-of-the-art theoretical model calculations, and might also point to the need for including three-body forces in the Hamiltonian

Towards the definition of the optimum height of voluminous cylindrical sources in gamma-ray spectroscopy

We show that for cylindrical voluminous sources in gamma-ray spectroscopy the relative error of the spectral intensity of a low-energy spectral line, as the height of the source increases, saturates faster than the spectral intensity itself. This significantly reduces the quantity of the required sample material as compared to that based on the usual considerations of the spectral intensity only. We also demonstrate that there exists a weakly pronounced height of the source (the sourer size) which minimizes the relative error of the intensity of a given low-energy spectral line, Due to the smallness of the effect the benefit of introducing the concept of the truly optimum size of the source is more on a psychological side, one should feel easier using an optimum quantity of the source material than merely a sufficient one, as is otherwise the case. (C) 1999 Elsevier Science Ltd. All rights reserved

Animation Content in Frame Analysis

Animation frame content is analyzed in this paper. The animation found in frame/video content is usually characterized by specific color distribution and texture. The existence of animation within a frame can be described by carefully selected features. We analyzed both fully and partially animated frames. Here, we present our initial results related to automatic animation interpretation using different types of video sequences

Biodiversity-friendly designs for gravel pit lakes along the Drina River floodplain (the Middle Danube Basin, Serbia)

Massive gravel excavation is one of the most destructive forces affecting riverine habitats in Europe. However, gravel pit lakes are also recognized as valuable wildlife refuge areas. Different hydromorphological characteristics of gravel pits may influence aquatic biota differently. Optimal selection of gravel excavation procedures may create favorable conditions for ecosystem diversity. The aim of this study was to correlate hydromorphological variables against macrophyte composition and metrics in gravel pit lakes along the lower course of the Drina River. Field research was carried out at 18 gravel pit lakes (60 survey sectors) and four fluvial lakes (13 survey sectors), during the summer months of 2015, 2016 and 2018. The role of hydromorphological variables in structuring macrophyte assemblages was tested using the partial Canonical Correspondence Analysis, while the Generalized Linear Model was performed to test the ability of selected hydromorphological attributes to predict macrophyte quantitative metrics. The results demonstrated high habitat quality and conservation value of the gravel pit lakes compared to natural sites. Hydromorphological predictors for different macrophyte assemblages were defined. General recommendation is that two pit types should be excavated within a single extraction field, with the minimal impact to the riparian and shore zones. The first type should be located up to 100 m from river main channel, having area < 1000 m2 and a relative depth ratio > 5%. The second type should be optimally located 300 m form river main channel, with maximum depth of 3–4 m, surface area of 10,000–20,000 m2, and a relative depth ratio < 5%

Changes in maximal oxygen uptake during growth and development in girls who actively participate in basketball and non-athletes girls: A longitudinal study

© 2018, Inst. Sci. inf., Univ. Defence in Belgrade. All rights reserved. Background/Aim. It is well known that continuous engagement in physical activity is important for normal growth and development of children. Maximal oxygen uptake (VO2max), as a measure of functional state of the organism, is largely affected by level of physical activity, but it remains unclear to what extent it can be improved during childhood. The aim of the study was to evaluate dynamics of changes in aerobic capacity, anthropometric and body composition characteristics in active and non-active girls over a period of 3 years. Methods. A total of 48 young girls were included in the study. Girls were divided into 2 groups: training group consisted of 25 girls who played basketball (age 13.84 ± 0.94) and non-training group of 23 girls who were not involved in any organized sports (age 13.83 ± 0.98). Anthropometric and body composition characteristics were measured in order to monitor somatic growth during the study. VO2maxvalues were obtained by performing cardiopulmonary exercise testing on a treadmill. All parameters were measured every 6 months during 3-years period. Results. ANOVA analysis showed a significant time and group interaction effect on VO2max (p < 0.001), body mass index (BMI) (p < 0.001) and fat percentage (FAT%) (p < 0.01). Also, there was an obvious increase in VO2max within both groups due to growth and development itself (p < 0.001). Conclusion. The main finding of the study was an increase in VO2max due to growth and development. The girls who actively participated in basketball had higher level of aerobic capacity compared to non-active girls. Furthermore, continuous basketball training led to maintaining normal body composition in terms of FAT% and BMI, which altogether may imply that organized physical activity has a positive influence on evaluated characteristics

Electron screening in palladium

The electron screening effect was studied in the 1H(7Li,α)4He, 1H(19F,αγ)16O and 2H(19F,p)20F nuclear reactions on two different hydrogen-containing palladium foils. In one of the targets we did not detect a large enhancement of the cross section due to electron screening, and in the second one we measured a high electron screening potential for all three reactions, up to an order of magnitude above the theoretical models. Contrary to the predictions given by the available theories, the data suggest that the reason behind this difference is linked to a dependence of the electron screening potential on the host's crystal lattice structure and the location of the target nuclei in the metallic lattice