Mathematical modelling as a tool to assessment of loads in volleyball player’s shoulder joint during spike     

Jacek Jurkojć  Robert Michnik  Krzysztof Czapla 《Journal of sports sciences》2017,35(12):1179-1186

This article deals with kinematic and kinetic conditions in volleyball attack and identifies loads in the shoulder joint. Joint angles and velocities of individual segments of upper limb were measured with the use of the motion capture system XSENS. Muscle forces and loads in skeletal system were calculated by means of mathematical model elaborated in AnyBody system. Spikes performed by players in the best and worst way were compared with each other. The relationships were found between reactions in shoulder joint and flexion/extension, abduction/adduction and rotation angles in the same joint and flexion/extension in the elbow joint. Reactions in shoulder joint varied from 591 N to 2001 N (in relation to body weight [BW] 83–328%).

The analysis proved that hand velocity at the moment of the ball hit (which varied between 6.8 and 13.3 m s^–1) influences on the value of reaction in joints, but positions of individual segments relative to each other are also crucial. It was also proved in objective way, that position of the upper limb during spike can be more or less harmful assuming that bigger reaction increases possibility of injury, what can be an indication for trainers and physiotherapists how to improve injury prevention.  相似文献   

The role of parents and peers in understanding female adolescent sexuality – testing perceived peer norms as mediators between some parental variables and sexuality     

Linda Rajhvajn Bulat  Marina Ajduković  Dea Ajduković 《Sex education》2016,16(5):455-470

Previous research has confirmed peers and parents as significant agents of socialisation with respect to young people’s sexuality. The aim of this cross-sectional cohort study was to examine how parental and peer variables predict young women’s sexual behaviour and sexuality-related thoughts and emotions, and whether perceived peer influences mediate the relationship between parental variables and young person sexuality. A total of 560 female high school students of 1st (mean age 15.56 years) and 3rd grade (mean age 17.55 years), selected by means of two-stage stratified probability sampling participated in the research. Results confirmed that peer variables explained considerably more variance in participant sexuality than parental variables. Indirect parental communication about sexuality was a significant positive predictor of sexual behaviour and sexuality-related thoughts and emotions in both subsamples. The strength of direct and indirect influences of parents and peers on young people’s sexuality is determined by the age of the young person and specific aspects of adolescent sexuality. Perceived percentage of sexually active peers was the only mediator in older participants, while in the younger subsample, additional peer variables mediated the association between some parental and sexuality variables. In the discussion, special attention is given to implications of these results for planning future forms of comprehensive sexual education.  相似文献   

The influence of experience on pre-service and novice teachers – the Croatian perspective     

Alma Škugor  Marija Sablić 《欧洲师范教育杂志》2018,41(2):157-168

This paper researches students’ and teacher trainees’ personal experience of student-centred teaching during their education in grades 1–4 of primary school. The questionnaire comprised 45 statements and was completed by 403 primary school teacher trainees and 535 students (future teachers) at Faculties of Teacher Education in Croatia. The research results show that students do not have sufficient prior experience that they could use as inspiration in their future teaching practice and that in the course of their education they were mainly exposed to traditional approach to teaching. The majority of teacher trainees are aware of the importance of student-centred teaching although they cannot fully give up the control of students and educational process. This research opens up the issue of a paradigm change within the teaching system and education in Croatia as well as the issue of changes within education and professional development of teachers.  相似文献   

Teaching informatics in primary schools: A Serbian experiment     

Dragan Vasić 《Prospects》1987,17(4):553-558

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Lev S. Vygotsky     

Ivan Ivić 《Prospects》1994,24(3-4):761-785

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Comparison of methods: Passing and Bablok regression     

Bilić-Zulle L 《Biochemia medica : ?asopis Hrvatskoga dru?tva medicinskih biokemi?ara / HDMB》2011,21(1):49-52

The comparison of methods experiment is important part in process of analytical methods and instruments validation. Passing and Bablok regression analysis is a statistical procedure that allows valuable estimation of analytical methods agreement and possible systematic bias between them. It is robust, non-parametric, non sensitive to distribution of errors and data outliers. Assumptions for proper application of Passing and Bablok regression are continuously distributed data and linear relationship between data measured by two analytical methods. Results are presented with scatter diagram and regression line, and regression equation where intercept represents constant and slope proportional measurement error. Confidence intervals of 95% of intercept and slope explain if their value differ from value zero (intercept) and value one (slope) only by chance, allowing conclusion of method agreement and correction action if necessary. Residual plot revealed outliers and identify possible non-linearity. Furthermore, cumulative sum linearity test is performed to investigate possible significant deviation from linearity between two sets of data. Non linear samples are not suitable for concluding on method agreement.  相似文献   

Work-related burnout syndrome in special education teachers working with children with developmental disorders – possible correlations with some socio-demographic aspects and assertiveness     

Vesna Jovanović  Jasmina Karić  Goran Mihajlović  Tamara Džamonja-Ignjatović 《欧洲特需教育杂志》2013,28(5):692-701

ABSTRACT

The aim of this research was to examine the levels of burnout syndrome dimensions in special education teachers and correlations with some socio-demographic characteristics, job characteristics, and levels of assertiveness. The research included 225 special education teachers from Serbia (82% were women, 18% were men, with the average age of 42.51 ± 9.23 years). Research instruments included Maslach Burnout Inventory, Rathus Assertiveness Schedule, and a socio-demographic questionnaire. There were differences in all burnout dimensions in relation to types of students’ special needs. Higher levels of burnout symptoms were observed in teachers working with children with motor skill disorders. The assertiveness scores had a significant negative correlation with emotional exhaustion and depersonalisation, and a positive correlation with a lack of accomplishment. The results obtained may help in the planning of the adequate preventative measures for improving the mental health of those professionals.  相似文献   

The science(s) of adult education     

Nikola Pastuović 《International Journal of Lifelong Education》2013,32(4):273-291

This article deals with the problems of forming a scientific system for adult education. The first part contains different concepts of sciences of education in developed countries, with a special emphasis on the difference between pedagogy as ‘practical theory’ and the sciences of education than can withstand meta‐scientific criteria. This is followed by a survey of the educological system of the knowledge of education, and the scientific and non‐scientific knowledge of adult education are contrasted. To enable us to distinguish unambiguously between scientific and non‐scientific knowledge the survey contains some major criteria for determining whether a discipline is a science or not. In this context andragogy, as well as pedagogy, are defined as ‘technological’ disciplines with the task of applying the principles discovered by the sciences of adult education: the educational psychology of adults, the sociology of adult education, the economics of adult education and the educational anthropology. In other words, andragogy is the ‘praxiology of adult education’, i.e. the science of applying scientific knowledge about adult education in the practice of that education. Andragogy could become ‘the general science of adult education’ and acquire a supra‐technological character if it grew into a science of the effectiveness of systems of adult education. In that case andragogy would study the interaction between the elements of the system as well as the interaction between these elements and the subsystems of the educational environment.  相似文献   

Truncation error analysis in computing of SEP and SEP floor for partially coherent receiver of MPSK signals over composite fading channels     

Zvezdan M. Marjanović  Goran T. Djordjević  Gradimir V. Milovanović 《Journal of The Franklin Institute》2018,355(2):965-980

In this paper, we analyze detection of multilevel phase-shift keying (MPSK) signals transmitted over a Gamma shadowed Nakagami-m fading channel. We derive novel analytical expression, in terms of Meijer’s G function, for Fourier coefficients of the probability density function of the received signal composite phase. Under the assumption of the imperfect reference signal extraction in the receiver, which is performed from the pilot signal, the analytical expression is derived for the symbol error probability (SEP) in the form of convergent series. The existence of the error floor is identified, and expression for its computation is provided. Mathematical proofs for convergence of Fourier series are provided for both SEP and SEP floor, and novel expressions of upper bounds for truncation errors are derived in terms of elementary mathematical functions. The convergence rate of the derived expressions is examined. Numerical results are confirmed independently by Monte-Carlo simulations.  相似文献   

Self-management in Yugoslav universities     

Branko Pribiévić Ph.D.  Jovan Ghgorijević Ph.D. 《Prospects》1973,3(4):515-521

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