scholarly journals Změny kinetických charakteristik odrazu volejbalistů mládežnických kategorií v průběhu šesti měsíců

2011 ◽  
Vol 5 (1) ◽  
pp. 25-32
Author(s):  
Pavel Korvas ◽  
Jaroslav Šamšula

The authors compare four variables of an attack jump between two groups of volleyball players, juniors and cadets. We observed during six months average strength of rebound, maximal impulse of strength, the time of whole rebound and the time reaching maximal impulse of strength. Th e group of juniors had better results for every parameter but cadets reached the highest improvement. Th e younger group gets to positive changes in average strength during rebound by 17,4 %, and for the time of whole rebound about 16,6 %. Maximal impulse of strength was increased by 3,9 % and the time reaching maximal impulse of strength was shorter 14,4 %. Juniors reached smaller changes than cadets, for average strength during rebound 9,2 %, maximal impulse of strength was increased by 12,5 % and the time of whole rebound about 10,6 %. Th e value of maximal impulse of strength was worst by 5,2 %. Th e both groups realized training programme of a very high quality, juniors 342 hours and cadets 211 hour of trainings load. Th e diff erences in results and value of changes are consequences of maturity, time of regular training process and performance level of our groups.

2004 ◽  
pp. 55-60

Abstract Hot isostatic pressing (HIP) is a process refinement available to address internal porosity in castings. The HIP process may be used, in particular, for applications requiring very high quality and performance. This chapter discusses the principles, advantages, and disadvantages of HIP. It describes the effect of HIP on tensile properties and on the fatigue performance of aluminum alloy castings. In addition, the chapter discusses the processes involved in radiographic inspection of HIP-processed castings.


sportlogia ◽  
2016 ◽  
Vol 12 (1) ◽  
pp. 1-16
Author(s):  
Tamara Karalić ◽  
◽  
Adriana Ljubojević ◽  
Nikolina Gerdijan ◽  
Željko Vukić ◽  
...  

Author(s):  
Suncica Pocek ◽  
Zoran Milosevic ◽  
Nemanja Lakicevic ◽  
Kristina Pantelic-Babic ◽  
Milka Imbronjev ◽  
...  

Although absolute jump heights should be considered an important factor in judging the performance requirements of volleyball players, limited data is available on age-appropriate categories. The purpose of this study is to determine the differences in specific anthropometric characteristics and jumping performance variables in under−19 female volleyball players in relation to playing position and performance level. The sample of subjects consisted of 354 players who prepared for the U19 Women’s Volleyball European Championship 2020 (17.4 ± 0.8 years, 1.81 ± 0.07 m, 67.5 ± 7.1 kg). Playing positions analyzed were setters (n = 55), opposites (n = 37), middle blockers (n = 82), outside hitters (n = 137), and liberos (n = 43). The results showed player position differences in every performance level group in variables of body height, spike, and block jump. Observed differences are a consequence of highly specific tasks of different positions in the composition of the team. Players of different performance levels are significantly different, with athletes of higher-ranked teams achieving better results. The acquired data could be useful for the selection and profiling of young volleyball players.


2011 ◽  
Vol 26 (15) ◽  
pp. 1059-1073
Author(s):  
CHRISTOS LEONIDOPOULOS

In 2010, the Compact Muon Solenoid (CMS) experiment at LHC recorded over 45 pb-1 of pp collision data at [Formula: see text]. The large collected datasets are of very high quality and have been used to commission and calibrate the CMS detector, with the achieved performance close to the TDR specifications. CMS has re-established all the major Standard Model processes in the 2010 Run and is entering new territory in searches for New Physics, with sensitivity already exceeding that at LEP and TeVatron.


Author(s):  
C. O. Jung ◽  
S. J. Krause ◽  
S.R. Wilson

Silicon-on-insulator (SOI) structures have excellent potential for future use in radiation hardened and high speed integrated circuits. For device fabrication in SOI material a high quality superficial Si layer above a buried oxide layer is required. Recently, Celler et al. reported that post-implantation annealing of oxygen implanted SOI at very high temperatures would eliminate virtually all defects and precipiates in the superficial Si layer. In this work we are reporting on the effect of three different post implantation annealing cycles on the structure of oxygen implanted SOI samples which were implanted under the same conditions.


1995 ◽  
Vol 32 (3) ◽  
pp. 339-348 ◽  
Author(s):  
M. B. Green ◽  
J. Upton

Reed bed treatment is put in the context of a major water company’s need to provide reliable, high quality, effluents from small sewage treatment works whilst seeking to minimise running costs. Design and operational information is given for reed bed applications in Severn Trent Water. Performance details are provided for application to secondary, tertiary and storm overflow treatment. The results give particular confidence in the system’s ability to deliver very high quality effluents when used for tertiary treatment, the company’s biggest application. Reed beds work well against less demanding criteria for secondary treatment at small sites and show great promise for storm overflow treatment.


Author(s):  
Daniel Suter ◽  
Caio Victor Sousa ◽  
Lee Hill ◽  
Volker Scheer ◽  
Pantelis Theo Nikolaidis ◽  
...  

In recent years, there has been an increasing number of investigations analyzing the effects of sex, performance level, and age on pacing in various running disciplines. However, little is known about the impact of those factors on pacing strategies in ultramarathon trail running. This study investigated the effects of age, sex, and performance level on pacing in the UTMB® (Ultra-trail du Mont Blanc) and aimed to verify previous findings obtained in the research on other running disciplines and other ultramarathon races. Data from the UTMB® from 2008 to 2019 for 13,829 race results (12,681 men and 1148 women) were analyzed. A general linear model (two-way analysis of variance (ANOVA)) was applied to identify a sex, age group, and interaction effect in pace average and pace variation. A univariate model (one-way ANOVA) was used to identify a sex effect for age, pace average, and pace variation for the fastest men and women. In our study, pace average and a steadier pace were positively correlated. Even pacing throughout the UTMB® correlated with faster finishing times. The average pace depended significantly on sex and age group. When considering the top five athletes in each age group, sex and age group also had significant effects on pace variation. The fastest women were older than the fastest men, and the fastest men were faster than the fastest women. Women had a higher pace variation than men. In male competitors, younger age may be advantageous for a successful finish of the UTMB®. Faster male runners seemed to be younger in ultramarathon trail running with large changes in altitude when compared to other distances and terrains.


Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4496
Author(s):  
Vlad Pandelea ◽  
Edoardo Ragusa ◽  
Tommaso Apicella ◽  
Paolo Gastaldo ◽  
Erik Cambria

Emotion recognition, among other natural language processing tasks, has greatly benefited from the use of large transformer models. Deploying these models on resource-constrained devices, however, is a major challenge due to their computational cost. In this paper, we show that the combination of large transformers, as high-quality feature extractors, and simple hardware-friendly classifiers based on linear separators can achieve competitive performance while allowing real-time inference and fast training. Various solutions including batch and Online Sequential Learning are analyzed. Additionally, our experiments show that latency and performance can be further improved via dimensionality reduction and pre-training, respectively. The resulting system is implemented on two types of edge device, namely an edge accelerator and two smartphones.


2021 ◽  
Vol 13 (5) ◽  
pp. 2705
Author(s):  
Hagen Deusch ◽  
Pantelis T. Nikolaidis ◽  
José Ramón Alvero-Cruz ◽  
Thomas Rosemann ◽  
Beat Knechtle

(1) Background: Compared with marathon races, pacing in time-limited ultramarathons has only been poorly discussed in the literature. The aim of the present study was to analyze the interaction of performance level, age and sex with pacing during 6 h, 12 h or 24 h time-limited ultramarathons. (2) Methods: Participants (n = 937, age 48.62 ± 11.80 years) were the finishers in 6 h (n = 40, 17 women and 23 men), 12 h (n = 232, 77 women and 155 men) and 24 h (n = 665, 166 women and 409 men) ultramarathons. The coefficient of variation (CV), calculated as SD/mean, was used to described pacing. Low scores of CV denoted a more even pacing, and vice versa. A two-way analysis of variance examined the main effects and interactions of sex and race duration on age, race speed and pacing. (3) Results: More men participated in the longer race distances than in the shorter ones and men were older and faster than women. Comparing the 6 h, 12 h and 24 h races, the finishers in the 6 h were the fastest, the finishers in the 12 h were the oldest and the finishers in the 24 h showed the most variable pacing. Furthermore, the faster running speed in the 12 h (women, r = −0.64; men, r = −0.49, p < 0.001) and the 24 h (r = −0.47 in women and men, p < 0.001) was related to less variable pacing. (4) Conclusions: These data might help runners and coaches to choose the the proper duration of a race and training programs for their athletes.


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