Competitive trait anxiety and general self-esteem of athletes according to the sport type and gender

Traditionally, anxiety has been interpreted as a negative emotional state characterized by nervousness, worry, fret, uncertainty and vague fear which could have an adverse effect on sports achievement. On the other hand, sport type and its specific nature and demands, may also be connected with the level of state and trait anxiety. This study aimed to investigate potential differences in the competitive trait anxiety level and general self-esteem according to gender in sports of different contact level. The sample consisted of 1024 (590 males and 434 females) young athletes. Independent variables were sport contact level (non-contact, contact and collision sports) and gender. Dependent variables were measured by the adjusted versions of Sport Competition Anxiety Test and Rosenberg Self-Esteem Scale. Basic descriptive statistics was calculated for all the groups, and the differences between them were established using χ² test and MANOVA. The results suggest significant differences in trait competitive anxiety per sport type, gender and their interaction, and no differences in the general self-esteem level. The current study reveals that not only the intensity but also the intergroup relationship of a sport contact level (non-contact, contact and collision sports) is gender determined. These findings are important in psycho-diagnostic procedure and choosing appropriate coping strategies for athletes

Unmanned aerial systems as a revolutionary tool in modern armed conflicts

More than a century has passed since the third dimension of space (airspace) has become an important place where combat and non-combat activities take place. The ability of the Air Force to carry out a wide range of content of combat operations and other activities from the airspace ensured the development of new qualitative characteristics of modern armed conflicts. The absence of physical limitations, high maneuverability and dynamism, short reaction time, as well as the high intensity of actions carried out by the Air Force, have enabled these forces to have strategic importance in armed conflicts since the Second World War. In parallel with the development of civilization and the emergence of qualitatively new technologies, rapidly improved technological solutions are being developed, which are changing the way of life of people around the world, improving it literally day by day. Each technological generation brings a new level of civilizational development, leading to the symbiosis of man as a human being and modern technical and technological means. Undoubtedly, this is also the case with the development of modern weapon systems and equipment used in armed conflicts. This is also the case with the revolutionary development of new weapon systems in air forces around the world. The development of modern weapons in the air force is best seen through the development of unmanned aerial platforms (unmanned aerial vehicles). The development of these assets is a consequence of the industrial revolution of the fourth generation and the importance of these platforms in the realization of tasks in modern armed conflicts is almost immeasurable. Namely, every conflict brings exponential development of these assets, both in technical and tactical sense. The development of these means in modern armed conflicts is a continuous process that is realized on the basis of previous experiences from the tactical use of unmanned aerial vehicles in concrete combat actions. There is no doubt that the technological progress of these means is something that in the future will enable the almost unlimited use of these aircraft in the execution of a wide variety of tasks without minimal danger to human life. This paper, whose main goal is to describe the unmanned aerial vehicle as a tool for the execution of a wide range of tasks in an unlimited war format, consists of three chapters in addition to the introduction and conclusion. In the first chapter, the theoretical determination of the unmanned aerial vehicle as a weapon-equipment system was made. In the second chapter, the use of unmanned aerial vehicles is analyzed on the examples of armed conflicts in Syria and Nagorno-Karabakh. In the third chapter, an analysis of potential aviation patterns of unmanned aerial vehicles and loitering munition (also known as a suicide drone or kamikaze drone) in combat operations was carried out

The prioritization of criteria for the selection of radar for the air traffic control and protection by multi-criteria decision: Making application in the fuzzy environment

The prioritization of criteria for the selection of radar for the air traffic control and protection by multi-criteria decision - making is presented in the paper. By analyzing the content of the available literature, the criteria and attributes of the criteria, on whose basis it is possible to evaluate the radar for the air traffic control, have been separated. The mutual influence of the criteria and attributes has been exerted by testing a group of experts using a questionnaire (the AHP questionnaire). The obtained values are fuzzificated in triangular fuzzy numbers. The processing of the gathered data - triangular fuzzy numbers and the prioritization of the criteria and attributes has been carried out by the AHP method. The consistency of the results has been tested by the ratio of consistency. On the basis of the results, the model that enables the selection of optimal radar for the air traffic control and protection has been proposed

Inteligentni robotski sistemi za ekstremno diverzifikovanu proizvodnju

U okviru ovog rada navode se rezultati sprovedenih istraživanja na četvorogodišnjem projektu TR35007 koji zajednički realizuju Mašinski fakultet Univerziteta u Beogradu, Fakultet tehničkih nauka Univerziteta u Novom Sadu i kompanija Ikarbus iz Beograda. Ovaj projekat finansijskih podržava Ministarstvo prosvete i nauke u okviru četovorogodišnjeg ciklusa istraživačkih projekata za tehnološki razvoj, od 2011. do 2014. godine. Prvo se navode istraživački okvir projekta, osnovni ciljevi koji postavljeni pred istraživački tim i organizacija projekta koja je izvedena po modelu radnih paketa. U drugom delu rada navode se osnovni rezultati ostvaranih u prvoj istraživačkoj godini, sa odgovarajućim opisom i osnovnim detaljima tehničke i organizacione prirode

Assessment of computed tomography simulators used in radiotherapy treatment planning in Serbia, Croatia, and Bosnia and Herzegovina

The purpose of this work was to evaluate computed tomography simulators used in radio-therapy treatment planning in Serbia, Croatia, and Bosnia and Herzegovina. A survey of quality assurance programmes of 24 computed tomography simulators in 16 facilities was conducted. A dedicated CT-to-ED phantom was scanned at 120 kV and 140 kV, to obtain CT-to-ED conversion curves as well as CTDIvol. Thoracal phantoms were scanned in the standard and extended field of view to evaluate the dosimetric effect on treatment planning and delivery. The mean age of the measured scanners was 5.5 years. The mean water HU value was –6.5 (all scanners, all voltages) and air HU value was –997. Extended field of view computed tomography data differ from the standard field of view and differences between conversion curves have significant dosimetric impact. The CTDI data showed a large range of values between centers. Better quality assurance of computed tomography simulators in all countries is recommended. The CT-to-ED curve could be used as default at one voltage and per manufacturer. Extended field of view imaging can be used, but treatment planning should be avoided in the regions out of the standard field of view

GM-CSF-Producing Th Cells in Rats Sensitive and Resistant to Experimental Autoimmune Encephalomyelitis

Given that granulocyte macrophage colony-stimulating factor (GM-CSF) is identified as the key factor to endow auto-reactive Th cells with the potential to induce neuroinflammation in experimental autoimmune encephalomyelitis (EAE) models, the frequency and phenotype of GM-CSF-producing (GM-CSF+) Th cells in draining lymph nodes (dLNs) and spinal cord (SC) of Albino Oxford (AO) and Dark Agouti (DA) rats immunized for EAE were examined. The generation of neuroantigen-specific GM-CSF+ Th lymphocytes was impaired in dLNs of AO rats (relatively resistant to EAE induction) compared with their DA counterparts (susceptible to EAE) reflecting impaired CD4+ lymphocyte proliferation and less supportive of GM-CSF+ Th cell differentiation dLN cytokine microenvironment. Immunophenotyping of GM-CSF+ Th cells showed their phenotypic heterogeneity in both strains and revealed lower frequency of IL-17+ IFN-gamma+, IL-17+ IFN-gamma-, and IL-17-IFN-gamma+ cells accompanied by higher frequency of IL-17-IFN-gamma- cells among them in AO than in DA rats. Compared with DA, in AO rats was also found (i) slightly lower surface density of CCR2 (drives accumulation of highly pathogenic GM-CSF+ IFN-gamma+ Th17 cells in SC) on GM-CSF+ IFN-gamma+ Th17 lymphocytes from dLNs, and (ii) diminished CCL2 mRNA expression in SC tissue, suggesting their impaired migration into the SC. Moreover, dLN and SC cytokine environments in AO rats were shown to be less supportive of GM-CSF+ IFN-gamma+ Th17 cell differentiation (judging by lower expression of mRNAs for IL-1 beta, IL-6 and IL-23/p19). In accordance with the (i) lower frequency of GM-CSF+ Th cells in dLNs and SC of AO rats and their lower GM-CSF production, and (ii) impaired CCL2 expression in the SC tissue, the proportion of proinflammatory monocytes among peripheral blood cells and their progeny (CD45(hi) cells) among the SC CD11b+ cells were reduced in AO compared with DA rats. Collectively, the results indicate that the strain specificities in efficacy of several mechanisms controlling (auto) reactive CD4+ lymphocyte expansion/differentiation into the cells with pathogenic phenotype and migration of the latter to the SC contribute to AO rat resistance to EAE

Many Labs 2: Investigating Variation in Replicability Across Samples and Settings

We conducted preregistered replications of 28 classic and contemporary published findings, with protocols that were peer reviewed in advance, to examine variation in effect magnitudes across samples and settings. Each protocol was administered to approximately half of 125 samples that comprised 15,305 participants from 36 countries and territories. Using the conventional criterion of statistical significance (p < .05), we found that 15 (54%) of the replications provided evidence of a statistically significant effect in the same direction as the original finding. With a strict significance criterion (p < .0001), 14 (50%) of the replications still provided such evidence, a reflection of the extremely highpowered design. Seven (25%) of the replications yielded effect sizes larger than the original ones, and 21 (75%) yielded effect sizes smaller than the original ones. The median comparable Cohen’s ds were 0.60 for the original findings and 0.15 for the replications. The effect sizes were small (< 0.20) in 16 of the replications (57%), and 9 effects (32%) were in the direction opposite the direction of the original effect. Across settings, the Q statistic indicated significant heterogeneity in 11 (39%) of the replication effects, and most of those were among the findings with the largest overall effect sizes; only 1 effect that was near zero in the aggregate showed significant heterogeneity according to this measure. Only 1 effect had a tau value greater than .20, an indication of moderate heterogeneity. Eight others had tau values near or slightly above .10, an indication of slight heterogeneity. Moderation tests indicated that very little heterogeneity was attributable to the order in which the tasks were performed or whether the tasks were administered in lab versus online. Exploratory comparisons revealed little heterogeneity between Western, educated, industrialized, rich, and democratic (WEIRD) cultures and less WEIRD cultures (i.e., cultures with relatively high and low WEIRDness scores, respectively). Cumulatively, variability in the observed effect sizes was attributable more to the effect being studied than to the sample or setting in which it was studied.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Sociales::Instituto de Investigaciones Psicológicas (IIP

Compliant behaviour of redundant robot arm - experiments with null-space

This paper presents theoretical and experimental aspects of Jacobian nullspace use in kinematically redundant robots for achieving kinetostatically consistent control of their compliant behavior. When the stiffness of the robot endpoint is dominantly influenced by the compliance of the robot joints, generalized stiffness matrix can be mapped into joint space using appropriate congruent transformation. Actuation stiffness matrix achieved by this transformation is generally nondiagonal. Off-diagonal elements of the actuation matrix can be generated by redundant actuation only (polyarticular actuators), but such kind of actuation is very difficult to realize practically in technical systems. The approach of solving this problem which is proposed in this paper is based on the use of kinematic redundancy and nullspace of the Jacobian matrix. Evaluation of the developed analytical model was done numerically by a minimal redundant robot with one redundant d.o.f. and experimentally by a 7 d.o.f. Yaskawa SIA 10F robot arm. [Projekat Ministarstva nauke Republike Srbije, br. TR35007