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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Vytipování genetické predispozice ovlivňující sportovní výkon se zaměřením na anaerobní aktivitu kosterní svalové činnosti / Identifying a genetic predisposition affecting sports performance, focusing on anaerobic activity of skeletal muscle activity

Balkó, Iva January 2017 (has links)
Title Identifying of genetic predisposition affecting sports performance focusing on anaerobic activity of skeletal muscle activity Problem Inborn predispositions of every individual are mainly influenced by the inherited genetic information in their DNA with the addition of external environmental factors. Based on the high variability of the inborn predictions in the form of phenotypic differences in the anatomy or physiology of an individual, it can be deduced on the connection between genetics and a specific sport talent. According to current scientific knowledge, anaerobic performance of the skeletal muscle tissue seems to be more genetically influenced. Anatomic and functional properties of the skeletal muscle are mainly influenced by genes, which have effect on the muscle fibre structure, blood storage, metabolism, neurotransmission, and muscle regeneration, etc. Fencing is a complex sport discipline where predispositions to speed and dynamic force play a key role. The sport performance in fencing, regardless of the type of weapon, is directly dependent on the interactions between the reaction of the fencer to the surrounding stimuli (visual, tactile), accuracy, tactical and technical skills, level of anticipation and overall physical a psychological readiness of the fencer. This work is...
12

Estudio sobre parámetros mecánicos y distancia de golpeo de Bandal Chagui de Taekwondo

Falcó Pérez, Coral 03 July 2009 (has links)
En este estudio se analizan los parámetros mecánicos fuerza de impacto (FI), tiempo de reacción (TR), tiempo de movimiento (TM), tiempo total de respuesta (TT) y dominancia, en la patada circular o Bandal Chagui en Taekwondo, basado en la regulación de la distancia de golpeo (ED1, ED2 y ED3). Para ello, se ha utilizado un sistema de nueva creación formado por una plataforma de contacto, una plataforma de fuerzas, un led de luces y un maniqui. La muestra esta compuesta por 51 taekwondistas (22 medallistas y 29 no medallistas; 37 varones y 19 mujeres; 42 diestros y 9 zurdos) de la Comunidad Valenciana con una media de edad de 24.49 años (DT = 5.94), una media de peso de 70.91 kg (DT = 12.95) y una longitud de pierna de 1.03 metros (DT = .06). En cuanto a la fuerza de impacto, los resultados muestran que los medallistas golpean con una mayor fuerza de impacto que los no-medallistas desde la distancia larga (D3) con ambas piernas y, desde la distancia corta (D1) con la pierna izquierda. Asimismo, los varones golpean con una mayor fuerza de impacto que las mujeres desde todas las distancias, excepto desde la distancia media (D2) con la pierna izquierda. Por otra parte, en el género varón, el peso tiene una relación positiva con la fuerza de impacto.En cuanto al tiempo de reacción, existen diferencias entre medallistas y no-medallistas desde la distancia media (D2) y larga (D3) con la pierna izquierda, mientras que el género no influye en el tiempo de reacción. En el tiempo de movimiento, no existen diferencias entre medallistas y no-medallistas ni entre varones y mujeres. Al mismo tiempo, el tiempo de reacción tiene una relación negativa con el tiempo de movimiento. Por su parte, los medallistas muestran un menor tiempo total de respuesta que los no-medallistas desde la distancia larga (D3) con la pierna izquierda, mientras que los varones golpean en un menor tiempo total de respuesta que las mujeres desde la distancia corta (D1). En cuanto a los análisis realizados teniendo en cuenta la dominancia, los medallistas muestran una asimetría en el tiempo de reacción desde la distancia larga (D3), mientras los no-medallistas muestran una asimetría en el tiempo total de respuesta desde las tres distancias planteadas (ED1, ED2 y ED3) y, en la fuerza de impacto desde la distancia corta (D1). El género varón muestra una asimetría en la fuerza de impacto desde la distancia corta (D1), mientras que en el género mujer no existen diferencias entre la pierna dominante y no-dominante. Así pues, la distancia de ejecución es un factor a tener en cuenta en la realización de una patada circular o Bandal Chagui medido con un sistema capaz de obtener datos objetivos del rendimiento mecánico mediante la estandarización de un protocolo, permitiendo diferenciar a los sujetos en función del nivel competitivo y del género, siendo una herramienta útil en el entrenamiento. / We analyzed the mechanical parameters impact force (FI), reaction time (TR), movement time (MT) and total response time (TT) and dominance in a roundhouse kick among three execution distances. To this end, a new system based in a contact platform, force platform, a led and a mannequin was used. The sample was composed by 51 taekwondo players (22 medallist and 29 non medallist; 37 male and 19 female) aged from 16 to 31 years (M = 24.49; S.D. = 5.9), weighing from 46 to 101 kg (M = 70.91; SD = 12.91) were selected to participate in the study. Medallists kicks with a higher FI from the long distance with both legs and from the shortest one with the left leg. Men kick with higher FI than women from all distances, except from the medium distance with the left leg. Significant differences have been found between medallists and non-medallist for RT from medium and large distance with the left leg, without differences among genere. No differences have been fount among movement time. Reaction time and movement time has a negative relation. Medallist had a less TT than non-medallist from the large distance with the left leg, while men kick with less TT than women from the shortest one. Medallist showed an asymmetry in RT from the large distance, while for non-medallist this asymmetry is showed in TT from all distances and in FI from the shortest distance. The execution distance is a parameter to take into account into a roundhouse kick performance.
13

Gesture-level model : A modified Keystroke-level model for tasks on mobile touchscreen devices

Nyström, Anton January 2018 (has links)
The aim of this thesis was to develop a touchscreen-adapted version of the well established Keystroke-level model, which is a user performance model designed to be a quick and easy way to evaluate user interfaces prior to creating prototypes. A quantitative research method was chosen to measure general execution times for common touchscreen gestures on mobile devices. Over 1000 data points were collected from participants who partook in a observational experiment using a prototype specifically programmed for this study. The results of the thesis involves the analyzed measurements acquired from the experiment, as well as a four important aspect to consider when performing similar experiments, namely: (1) The individual speed of the participants; (2) The participants’ level of expertise; (3) The participants’ methods of performing the gestures; (4) Designing the experiment for medium difficulty. / Målet med denna uppsats var att utveckla en pekskärmsanpassad version av den välkända modellen Keystroke-level model, vilket är en modell som kan användas för att snabbt och enkelt utvärdera gränssnitt utan att behöva utveckla fungerande prototyper. En kvantitativ forskningsmetod användes för att mäta hur lång tid det tar för användare generellt att utföra de vanligaste fingergesterna på mobila pekskärmar. Över 1000 datapunkter samlades in från ett experiment där deltagarna fick använda en prototyp som automatiskt mätte den tid det tog för användarna att utföra de olika fingergesterna. Resultaten av studien består av de mätvärden som räknats ut samt fyra aspekter som är viktiga att ha i beaktning när liknande experiment ska utformas. Dessa är: (1) Varje deltagares individuella hastighet; (2) Deltagarnas pekskärmsvana; (3) Sättet de olika deltagarna utför fingergesterna; (4) Utforma experimentet för att representera en medium svårighetsgrad. / Le but de ce projet fut de créer une version du Keystroke-level model adaptée aux écrans tactiles. Ce modèle de performance utilisateur est une méthode d’évaluation simple et rapide d’interfaces utilisateur avant la création de prototypes. Une étude quantitative fut choisie pour mesurer le temps d’exécution général de mouvements spécifiques effectués sur des écrans tactiles de téléphones. Plus de 1000 points de données furent collectés auprès de participants ayant pris part à une étude observationnelle utilisant un prototype spécialement programmé pour l’occasion. Les résultats de ce projet incluent l’analyse des mesures acquises lors de cette étude ainsi que quatre aspects importants à considérer lors de la réalisation d’études similaires, à savoir: (1) La vitesse individuelle des participants; (2) Le niveau d’habitude d’utilisation d’écrans tactiles des participants; (3) Les méthodes utilisées par les participants lors de la réalisation des mouvements; (4) La conception d’étude pour des mouvements de difficulté dite moyenne.
14

Effects of Transcranial Direct-Current Stimulation on Gait Initiation in People with Parkinson’s Disease

Lommen, Jonathan Lyon Jacob 16 December 2019 (has links)
Background: Gait initiation is a major issue in Parkinson’s disease (PD). Moreover, the effect of current treatment on motor deficits vary alongside individual differences and disease severity. In some cases, postural instability has been documented as a major side-effect and refractory symptom to dopaminergic medication. Despite these shortcomings, research involving other forms of therapy including deep brain stimulation (DBS) and transcranial magnetic stimulation (TMS), has evidenced the improvement of postural deficits in PD. In this regard, there is a strong rational for the modulation of subcortical brain activity via the application of non-invasive transcranial direct current stimulation (tDCS) to interconnected cortical brain structures. Purpose: Therefore, we sought to determine the effect of tDCS applied to the supplementary motor area (SMA), on gait initiation preparation and performance in PD. Methods: A within subjects repeated measures quasi-experimental design was used to investigate the effects of a 10-minute sham-controlled tDCS intervention. Clinically diagnosed participants (n=12) with idiopathic PD were tested on medication during two sessions that bookended one week. Those who had previously undergone other forms of brain stimulation, had diabetes, severe freezing of gait, or any other neurological or functional limitations that could interfere with gait initiation were excluded from the study. Statistical Analyses/Results: Two-way repeated measures ANOVAs with Bonferroni corrections and a post-hoc analyses when appropriate, revealed a significant reduction in the magnitude of center of pressure (CoP) displacement and velocity in the mediolateral (ML) direction following tDCS. Conclusions: Findings from this study provide insights that may guide scientific research regarding the effects of tDCS on gait initiation among those with PD. Additionally, our work may highlight the importance of ML postural stability for individuals with comorbid and/or pharmacologically induced postural instabilities.

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