Effects of forearm wearable resistance during accelerated sprints: From a standing start position

2021 ◽  
pp. 1-8
Author(s):  
Aaron M. Uthoff ◽  
Paul Macadam ◽  
James Zois ◽  
Ryu Nagahara ◽  
Jono Neville ◽  
...  
Keyword(s):  
Start Position ◽  
Standing Start

scholarly journals Model Gaya Kepemimpinan dalam Kelompok Musik Kiai Kanjeng

2017 ◽  
Vol 2 (1) ◽  
pp. 58-73
Author(s):  
Muhammad Tahdianoor
Keyword(s):  
Transformational Leadership ◽  
Data Analysis ◽  
Leadership Style ◽  
Qualitative Researcher ◽  
Study Approach ◽  
Laissez Faire ◽  
Smoking Control ◽  
Transformational Leadership Style ◽  
Standing Start

Banyak faktor yang membuat Kiai Kanjeng memiliki banyak prestasi. Salah satu faktor pentingnya adalah gaya kepemimpinan Emha Ainun Nadjib (Cak Nun) dalam memimpin Kiai Kanjeng. Karena itu peneliti tertarik untuk mengidentifikasi karakteristik gaya kepemimpinan dan merumuskan model gaya kepemimpinan Cak Nun dalam memimpin Kiai Kanjeng. Metode penelitian yang digunakan peneliti adalah kualitatif. Hasil analisis data berdasarkan teori gaya kepemimpinan dengan pendekatan studi kasus. Pengambilan data dilakukan dengan cara observasi, dokumentasi dan mewancarai beberapa narasumber yang dianggap penting dalam penelitian ini. Berdasarkan analisa data dalam penelitian ini, karakteristik gaya kepemimpinan yang identik dengan Cak Nun secara keseluruhan cenderung memenuhi katagori gaya kepemimpinan transformasional. Gaya kepemimpinan Cak Nun yang berbeda-beda berimplikasi pada kesolidan anggota, kreatif, eksis dan mempunyai penggemar yang militan sehingga Kiai Kanjeng mampu bertahan sampai sekarang. Model gaya kepemimpinan Kiai Kanjeng yang dipimpin oleh Cak Nun yaitu, otokrasi, demokrasi, kendali bebas (laissez faire) dan partisipatif, tergantung pada kegiatan Kiai Kanjeng. Kiai Kanjeng from a standing start (1993) to the present (2016) already has been many achievements. It is the result of the leadership style by Emha Ainun Nadjib (Cak Nun) led Kiai Kanjeng. Thus the researchers are interested in identifying the characteristics of leadership style and formulate a model of leadership style in leading Cak Nun Kiai Kanjeng. Bernard M. Bass suggests that transformational leadership is the leader to encourage, motivate and innovate the members to do something beyond their own ability to improve the life of the group. The method used is a qualitative researcher. The results of data analysis are based on the theory of leadership style with a case study approach. Further data collection is done by observation, documentation and interviewed several sources that are considered in this study. Based on data analysis in this study, the characteristics of leadership style that is synonymous with Cak Nun meet category leadership style autocracy, democracy, free rein (laissez faire), participative and transformational in accordance with the activity. Cak Nun's leadership style is different implications for the solidity member, creative, exist and has fans that are militants so Kiai Kanjeng is able to survive until now. Cak Nun implements smoking-control leadership style transformational in schedulingduration exercise, discipline personnel and development staff resources (managerial). Cak Nun applies autocrary-transformational leadership style in addressing the invitation and when determining the strat-stoping song and song capabilities in the development ao lead- singger and composition/arrangement. Cak Nun apply transformational leadership style, autocrary and democratic in prepariation for staging. Cak Nun implements free rein, democratic, transformational leadership style when staging evaluation. Overall, there is a leadership style that is the same in each process, the transformational leadership style.

scholarly journals Research on Tool Presetting and Tool Deviation in CNC Lead Screw Grinding Process

2021 ◽  
Author(s):  
Donghong Hu ◽  
Kai Wang ◽  
Ling Zhang ◽  
Pingjiang Wang ◽  
Guang Chen
Keyword(s):  
Grinding Wheel ◽  
Grinding Process ◽  
Current Position ◽  
Cnc System ◽  
Start Position ◽  
Root Cause ◽  
Lead Screw ◽  
Pitch Length ◽  
Following Error ◽  
Screw Pitch

Abstract In the process of tool presetting for an CNC lead screw grinding, when A-axis rotating and Z-axis shifting synchronously according to the screw pitch length, L, of the lead screw workpiece, the handwheel corresponding to X-axis and Z-axis, respectively, is operated to align the grinding wheel with the middle of the screw groove. Then, the coordinates of Z-axis, A-axis and X-axis of the current position are recorded, and the coordinates of the grinding start position and grinding end position of the lead screw workpiece are calculated accordingly.However, due to the mutual following error of Z-axis and A-axis in the synchronous movement process, tool deviation typically occurs when the grinding wheel moves from the grinding start position to the grinding end position to grind the lead screw workpiece. More specifically, the grinding wheel slightly deviates from the middle of the screw groove to the left or right of the screw groove.To offset this deviation, the root cause for creating the deviation is analyzed, and a method to correct the tool deviation is proposed: First, the CNC system sends out grinding instructions, according to the requirements of grinding process, to make the A-axis and the Z-axis move synchronously. In the meantime, the CNC system measures and records the current coordinates of A-axis and Z-axis, and calculates the tool deviation caused by the mutual following error between Z-axis and A-axis. As a result the grinding start position and the grinding end position are adjusted in light of the value of tool deviation in the subsequent grinding process, so as to address the tool deviation issue.

UAS Mission Path Planning System (MPPS) Using Hybrid-Game Coupled to Multi-Objective Optimiser

2009 ◽  
Author(s):  
DongSeop Lee ◽  
Jacques Periaux ◽  
Luis Felipe Gonzalez
Keyword(s):  
Path Planning ◽  
Computational Cost ◽  
Optimization Techniques ◽  
Planning System ◽  
Unmanned Aerial Systems ◽  
Three Dimension ◽  
Design Quality ◽  
Nsga Ii ◽  
Start Position ◽  
Multi Objective

This paper presents the application of advanced optimization techniques to Unmanned Aerial Systems (UAS) Mission Path Planning System (MPPS) using Multi-Objective Evolutionary Algorithms (MOEAs). Two types of multi-objective optimizers are compared; the MOEA Non-dominated Sorting Genetic Algorithms II (NSGA-II) and a Hybrid Game strategy are implemented to produce a set of optimal collision-free trajectories in three-dimensional environment. The resulting trajectories on a three-dimension terrain are collision-free and are represented by using Be´zier spline curves from start position to target and then target to start position or different position with altitude constraints. The efficiency of the two optimization methods is compared in terms of computational cost and design quality. Numerical results show the benefits of adding a Hybrid-Game strategy to a MOEA and for a MPPS.

scholarly journals Acute Effects of a Speed Training Program on Sprinting Step Kinematics and Performance

2019 ◽  
Vol 16 (17) ◽  
pp. 3138 ◽  
Author(s):  
Krzysztof Mackala ◽  
Marek Fostiak ◽  
Brian Schweyen ◽  
Tadeusz Osik ◽  
Milan Coch
Keyword(s):  
Intervention Program ◽  
Sprint Performance ◽  
Elite Group ◽  
Standing Long Jump ◽  
Post Test ◽  
Long Jump ◽  
And Performance ◽  
Speed Training ◽  
Standing Start ◽  
Block Start

The purpose of this study was to examine the effects of speed training on sprint step kinematics and performance in male sprinters. Two groups of seven elite (best 100-m time: 10.37 ± 0.04 s) and seven sub-elite (best 100-m time: 10.71 ± 0.15 s) sprinters were recruited. Sprint performance was assessed in the 20 m (flying start), 40 m (standing start), and 60 m (starting block start). Step kinematics were extracted from the first nine running steps of the 20-m sprint using the Opto-Jump–Microgate system. Explosive power was quantified by performing the CMJ, standing long jump, standing triple jump, and standing five jumps. Significant post-test improvements (p < 0.05) were observed in both groups of sprinters. Performance improved by 0.11 s (elite) and 0.06 s (sub-elite) in the 20-m flying start and by 0.06 s (elite) and 0.08 s (sub-elite) in the 60-m start block start. Strong post-test correlations were observed between 60-m block start performance and standing five jumps (SFJ) in the elite group and between 20-m flying start and 40-m standing start performance and standing long jump (SLJ) and standing triple jump (STJ) in the sub-elite group. Speed training (ST) shows potential in the reduction of step variability and as an effective short-term intervention program in the improvement of sprint performance.

Navicula Drop Test Ad Modum Brody

2012 ◽  
Vol 102 (1) ◽  
pp. 34-38 ◽  
Author(s):  
Michael Skovdal Rathleff ◽  
Rasmus Gottschalk Nielsen ◽  
Uwe G. Kersting
Keyword(s):  
Treadmill Walking ◽  
Heel Strike ◽  
Clinical Test ◽  
Start Position ◽  
Foot Motion ◽  
Foot Pronation ◽  
Analysis System ◽  
Asymptomatic Individuals ◽  
Dynamic Measures ◽  
And Function

Background: Understanding foot motion and function during activity is essential for clinicians because different foot types may require different treatment or rehabilitation strategies. Brody introduced the static navicular drop (ND) test, which was meant as a quick clinical test to estimate foot pronation during dynamic conditions. However, how well static ND predicts dynamic ND during walking has never been investigated. The purpose of this study was to investigate how well static ND corresponds to dynamic measures of ND during treadmill walking. Methods: A custom video analysis system was used to assess dynamic ND during treadmill walking. The ND test ad modum Brody was used to evaluate static ND. Results: Static ND showed a significant correlation with dynamic ND (r = 0.357, r2 = 0.127, P &lt; .001). Navicular height at heel strike demonstrated a significant correlation with navicular height at the start position of static ND (r = 0.756, r2 = 0.571 P &lt; .001). Minimal navicular height during walking was significantly correlated with the end position of static ND (r = 0.951, r2 = 0.904, P &lt; .001). Conclusions: This study of asymptomatic individuals did not confirm that static ND can be used to individually predict dynamic ND during treadmill walking. It was demonstrated that the start position of Brody’s test is not well correlated with navicular height at heel strike, with this being the main reason for the weak relationship between static and dynamic ND measures. (J Am Podiatr Med Assoc 102(1): 34–38, 2012)

scholarly journals The Impact of Different Competitive Environments on Pacing and Performance

2018 ◽  
Vol 13 (6) ◽  
pp. 701-708 ◽  
Author(s):  
Marco J. Konings ◽  
Florentina J. Hettinga
Keyword(s):  
Fixed Effects ◽  
Linear Models ◽  
Real Life ◽  
Energy Resources ◽  
Mixed Linear Models ◽  
Start Position ◽  
Available Energy ◽  
Competitive Environments ◽  
And Performance ◽  
The Impact

Purpose: In real-life competitive situations, athletes are required to continuously make decisions about how and when to invest their available energy resources. This study attempted to identify how different competitive environments invite elite short-track speed skaters to modify their pacing behavior during head-to-head competition. Methods: Lap times of elite 500-, 1000- and 1500-m short-track speed skating competitions between 2011 and 2016 (N = 34,095 races) were collected. Log-transformed lap and finishing times were analyzed with mixed linear models. The fixed effects in the model were sex, season, stage of competition, start position, competition importance, event number per tournament, number of competitors per race, altitude, and time qualification. The random effects of the model were athlete identity and the residual (within-athlete race-to-race variation). Separate analyses were performed for each event. Results: Several competitive environments, such as the number of competitors in a race (a higher number of competitors evoked most likely a faster initial pace; coefficient of variation [CV] = 1.9–9.3%), the stage of competition (likely to most likely, a slower initial pace was demonstrated in finals; CV = −1.4% to 2.0%), the possibility of time qualification (most likely a faster initial pace; CV = 2.6–5.0%), and competition importance (most likely faster races at the Olympics; CV = 1.3–3.5%), altered the pacing decisions of elite skaters in 1000- and 1500-m events. Stage of competition and start position affected 500-m pacing behavior. Conclusions: As demonstrated in this study, different competitive environments evoked modifications in pacing behavior, in particular in the initial phase of the race, emphasizing the importance of athlete–environment interactions, especially during head-to-head competitions.

scholarly journals Levels of Agreement for the Direction of Inter-Limb Asymmetry during Four Simple Change-of-Direction Tests in Young Male Handball Players: A Pilot Study

Symmetry ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1940
Author(s):  
Žiga Kozinc ◽  
Chris Bishop ◽  
Jernej Pleša ◽  
Nejc Šarabon
Keyword(s):  
Pilot Study ◽  
Effect Size ◽  
Young Male ◽  
Trade Off ◽  
Change Of Direction ◽  
Task Time ◽  
Simple Change ◽  
Limb Asymmetry ◽  
Mean Differences ◽  
Standing Start

The purpose of this pilot study was to investigate the effects of change-of-direction (CoD) angle (90° vs. 180°) and the inclusion of acceleration approach on total task time, CoD deficit, and agreement regarding inter-limb asymmetry direction across CoD tasks. The sample included 13 young male handball players (age: 22.4 ± 3.2 years). The CoD tasks were performed over a 10 m distance with 90° and 180° turns. Both CoD tasks were performed under two conditions: (1) from the standing start and, (2) with a 10 m prior acceleration approach. Linear sprint times over a 10 m distance were also recorded for the purpose of determining the CoD deficit. The differences between the outcomes of different test variants were assessed with pairwise t-tests and associated Cohen’s d effect size. The agreement in terms of inter-limb asymmetry direction was assessed descriptively, using percentage of agreement. Results showed that the inclusion of the 10 m approach reduced the total task time (mean differences ranging between 0.26 and 0.35 s; d = 2.27–4.02; p < 0.002). The differences between 90° and 180° turn times were statistically significant under both conditions: (a) without approach (0.44–0.48 s; d = 4.72–4.84; all p < 0.001), and (b) with approach (0.50–0.54 s; d = 4.41–5.03; p < 0.001). The agreement regarding inter-limb asymmetry direction among the tasks was 30.7–61.5%. The differences between the tasks could be explained by the angle–velocity trade-off. The results of this study imply that the CoD tasks should not be used interchangeably when assessing inter-limb asymmetries.

scholarly journals Canonical relations between anthropometric and motor dimensions among 12-year-old students

2021 ◽  
Vol 8 (1) ◽  
pp. 49-67
Author(s):  
Miroljub Ivanović ◽  
Uglješa Ivanović
Keyword(s):  
Motor Skills ◽  
Body Height ◽  
Morphological Characteristics ◽  
Linear Functions ◽  
Significance Level ◽  
Anthropometric Characteristics ◽  
Hand Tapping ◽  
Foot Tapping ◽  
High Level ◽  
Standing Start

The aim of this empirical research was to examine the correlations between the groups of variables of anthropometric characteristics (16) and motor skills (21) among 154 students (AM = 11,53 SD = 1,12). The method of canonical correlation analysis was used to assess the correlation between the pairs of linear functions of predictor and criterion variables. The obtained canonical coefficients and canonical weights revealed that, with significance level (p ≤ 0,0,5 or p ≤ 0,01), there is a high level of correlation between linear combinations of the examined morphological characteristics and motor skills, where the explained mutual variance was 80% for the first and 33% for the second canonical function. The extracted relevant canonical pairs were interpreted hypothetically as "integrated morphological factor and the factor of static and repetitive strength and coordination", and the second one was interpreted as "morphological factor and the factor of explosive strength". The set of the first canonical morphological factor and the factor of static and repetitive strength, and coordination, is the maximum weight on the variables body mass, body height, forearm circumference, horizontal reverse plank, knee push-ups, and stick mobility, while the biggest contribution to the structure of the second canonical morphological factor and the factor of static and repetitive strength have variables 20m sprint with standing start, standing long jump, hand tapping and foot tapping. The obtained results of the analyzed bicomponent canonical model reveal more defined and predictable structure of the correlation between anthropometric characteristics and motor manifestations, and therefore give guidelines for planning, developing and controlling the training processes during physical education classes.

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