119 research outputs found
Futboleko lesioen epidemiologiaren, arrisku faktoreen eta ondorioen ikerketa Athletic Cluben.
125 p.Tesi honen helburua Athletic Clubeko zerbitzu medikuaren lesioaren kudeaketa hobetzeko 3 galdera erantzutea izan zen. 1. Ikerlanean, gizonezkoen eta emakumezkoen lesioen epidemiologian ezberdintasunak daudela, eta prebentzio estrategiak bakoitzaren beharretara egokitu behar direla azalarazi zen. 2. Ikerlanean, 37 nukleotido bakarreko polimorfismo eta iskiotibialetako lesio muskularren arteko asoziazioa ikertu zen gizonezko jokalari helduetan. Nahiz eta 5 polimorfismo eta adina lesionatzeko arriskuarekin asoziatu ziren, ereduak ez zuen lesioak aurresateko gaitasunik eduki denboraldi independente batean, eta genetikaren erabilera lesioei dagokienez goiztiarra da. 3. Ikerlanean, lesioek harrobiko gizonezko jokalarien progresioan eta Lehen taldera iristeko aukeretan inpaktu negatiboa dutela demostratu zen. Lesioaren kudeaketa lehentasun bat da goi-mailako harrobietan, eta informazio hau jokalarien, entrenatzaileen eta zuzendarien atxikimendu maila handitzeko erabili daiteke. Galdera hauen erantzunetatik harago, garrantzitsua dena erantzunak bilatzeko prozesua da. Ebidentzian oinarritutako prozesu hau klubetan eta profesional bakoitzaren praktikan txertatzea helburu garrantzitsua da etorkizunera begira, jokalarien errendimendua eta lesioaren kudeaketa hobetzeko beste pauso bat
ROCOV scheme for Fault Detection and Location in HVDC sytems
A reliable DC fault protection system is essential
for the development of HVDC grids. Therefore, this paper deals
with the voltage derivative ROCOV scheme to locate and detect
DC faults. The algorithm is able to differentiate internal and
external faults considerably fast. The proposed algorithm is
analyzed in a HVDC grid with different fault case scenarios.
Finally, the ROCOV protection thresholds are discussed.The authors thank the support from the Spanish Ministry of
Economy, Industry and Competitiveness (project
ENE2016-79145-R AEI/FEDER, UE) and GISEL research
group IT1083-16), as well as from the University of the
Basque Country UPV/EHU (research group funding
PPG17/23)
Matematika eta hizkuntzaren lanketa bost urteko gelan: Arbela digitalerako proiektua
Haur Hezkuntzan umeek bizitzarako beharrezkoak dituzten
konpetentziak garatu eta garapen integrala bermatzea da helburua. Egun, gizartean
teknologiaren presentzia handia den arren, eskoletan ez da hori gertatzen; bien artean
arrakala digitala dagoela esan daiteke. Baliabide teknologikoak umeen garapenerako
aukera anitzak ematen dituzte; beraz, ikuspegi pedagogiko egokiarekin, baliabide
aproposak dira Haur Hezkuntzarako. Hutsune hori ikusiz, eta arbela digitalak ematen
dituen aukerak aztertuta, Haur Hezkuntzako bost urteko gelarako arbela digitalerako
unitate didaktikoa sortu da. Bertan, matematikari eta hizkuntzari lotutako konpetentzian
lanketa egingo da, frutak eta barazkiak lantzen diren bitartean. Umeak konpetentzia
digitaletan trebatzea ere bilatuko da, etorkizunerako beharrezkoa izango dutelako.
Proposamen honetan, konpetentzietan oinarrituriko ikaskuntzatatik abiaturiko proiektua
planteatuko da
Evaluation of a Local Fault Detection Algorithm for HVDC Systems
A great increase in the amount of energy generated from clean and renewable sources integrated in the electric power system is expected worldwide in the coming years. High Voltage Direct Current (HVDC) systems are seen as a promising alternative to the traditional Alternating Current (AC) systems for the expansion of the electric power system. However, to achieve this vision, there are some remaining challenges regarding HVDC systems which need to be solved. One of the main challenges is related to fault detection and location in HVDC grids. This paper reviews the main protection algorithms available and presents the evaluation of a local fault detection algorithm for DC faults in a multi-terminal Voltage Source Conversion (VSC) based HVDC grid. The paper analyses the influence of the DC voltage sampling frequency and the cable length in the performance of the algorithm. © 2019, European Association for the Development of Renewable Energy, Environment and Power Quality (EA4EPQ).The authors thank the support from the Spanish Ministry of Economy, Industry and Competitiveness (project ENE2016-79145-R AEI/FEDER, UE) and GISEL research group IT1083-16), as well as from the University of the Basque Country UPV/EHU (research group funding PPG17/23)
Modelling of Resistive Type Superconducting Fault Current Limiter for HVDC Grids
The protection of high voltage direct current (HVDC) grids is a challenge considering that the protection system must detect, locate, and interrupt large fault currents in a few milliseconds. Resistive type superconducting fault current limiters (R-SFCL) can help solve that difficult task, reducing the extremely demanding ratings of HVDC circuit breakers. This paper presents different approaches to model R-SFCLs in order to analyze their suitability for assessing the performance of HVDC grid protection, including the step model, the exponential model, the RQ model, and the magneto-thermal model. In the first instance, the R-SFCL models are evaluated in a test grid to analyze their parameterisation and select the most adequate model for the study of HVDC grids. The RQ model is finally chosen for its simplicity but closer behavior to the magneto thermal model in terms of fault resistance dependency and resistance evolution curve. Then, the performance of an RQ type R-SFCL model in conjunction with a mechanical circuit breaker is evaluated in a multiterminal HVDC grid with different fault cases. This way, fault currents are greatly decreased as well as circuit breaker requirements. Hence, the R-SFCL under study enables a reliable protection of the HVDC grid
Fault detection based on ROCOV in a multi-terminal HVDC grid
Protection of a meshed VSC-HVDC grid is a challenge due to the behaviour of DC current and voltage signals during fault conditions. Protection systems must operate in a very short time range. Since fault detection should be very fast, local measurement based algorithms are mostly used; communication based algorithms lack the needed speed as a result of the communication time delay. This way, a ROCOV algorithm is proposed in this paper. This algorithm is analysed for different fault conditions.The authors gratefully acknowledge the support from the Spanish Ministry of Economy, Industry and Competitiveness (project ENE2016-79145-R AEI/FEDER, UE), the Basque Government (GISEL research group IT1191-19), as well as from the University of the Basque Country UPV/EHU (research group funding GIU18/181)
The relative age effect in young athletes: a countywide analysis of 9–14-year-old participants in all competitive sports
[EN] The relative age effect (RAE) has primarily been investigated in male athletes involved in
popular sports and high-level competitions. However, occurrence of RAE in other types of
sports at the grassroots level, particularly in female athletes, is less well-studied. Thus, we
examined the RAE in a large cohort of young athletes who participated in all competitive
sports in Bizkaia, Spain, according to gender and specificity of the sport. The birth dates of
38,381 participants (65.1% males and 34.9% females) aged 9–14 years old in 37 competitive
sports were analyzed. Birth dates were divided into four birth-quarters and compared to
those of all children born in the same period using a χ2 goodness-of-fit test and standardized
residuals. The effect size Cramer’s V was measured, and odds ratio and 95% confidence
intervals were calculated to determine the odds of athletes born in January playing in the
highest leagues. In the total sample, in boys RAE was evident in football, but only in highercompetition
leagues (p<0.001, large effect size). In girls, RAE was evident in the most popular
team sports: basketball (p<0.001, large effect size in basketball 1st league), handball and
football (p<0.05, both small effect sizes). Players born in January were 3.23- and 2.89-times
more likely to play in the 1st leagues than those born in December, for boys (football) and
girls (basketball) respectively. In the overall analysis and in the remaining sports, presence
of RAE was negligible. Therefore, the date of birth does not seem to be a constraint to participating
in most sports in Bizkaia. The potential mechanisms for RAE are multifactorial and
complex, yet a combination of factors, such as the popularity of a sport and the depth of
competition, physicality and social influences may be involved. We discuss these mechanisms
and potential measures to mitigate RAE.This work was partially supported by the
University of the Basque Country (UPV/EHU)
(https://www.ehu.eus/es/) under grant PPGA19/53
and the Basque government (https://www.euskadi.
eus/gobierno-vasco/inicio/) under grant IT922-16.
The funders had no role in study design, data
collection and analysis, decision to publish, or
preparation of the manuscript
The combined effects of growth and maturity status on injury risk in an elite football academy
This study aimed to explore the interaction between growth rate on specific injury incidence and burden on pre-, circa- and post-peak height velocity (PHV) periods. Injury and stature data collected during the 2000–2020 seasons in an elite football academy were retrospectively analysed. Only players with height measurements from childhood until the attainment of adult height were included in the study (N = 84). Growth data were smoothed using a cubic spline to calculate daily growth rate and height. Growth rate was categorised into three groups: fast (> 7.2 cm/year), moderate (3.5–7.2 cm/year) and slow (< 3.5 cm/year). Percentage of observed adult height was used to classify players as pre-PHV (< 88%), circa-PHV (88–95%) or post-PHV (> 95%). Overall and specific injury incidence and burden and rate ratios for comparisons between growth rate groups were calculated on pre-, circa- and post-PHV periods, separately. Overall injury incidence and burden were greater in pre-PHV players with quicker growth rates compared to players growing moderately and slowly. All in all, players with more rapid growth-rates were at higher risk for growth-related injuries in all pre-, circa- and post-PHV periods. Post-PHV, the incidence and burden of joint/ligament injuries were 2.4 and 2.6-times greater in players growing slowly compared to players growing moderately. Practitioners should monitor growth rate and maturity status and consider their interaction to facilitate the design of targeted injury risk reduction strategies
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