• Korean Journal of Applied Biomechanics
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• v.24 no.4
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• pp.367-373
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• 2014

Most athletes execute rhythmic hop as a preparatory motion in Taekwondo sparring. The purpose of this study was to investigate the effect of rhythmic hop on the response times and kicking velocities of Taekwondo kicks. Twelve male elite Taekwondo athletes performed a roundhouse kick and a back kick as fast as possible immediately after seeing an external stimulus in rhythmic hop and in no hop, respectively. The three-dimensional marker data of the whole body were measured at sampling rate of 200 Hz. Paired t-tests were used to compare dependent measures between hop and no hop conditions. Results indicated that the rhythmic hop did not affect response time statistically but improved the kicking velocity significantly than no hop did. Different instants of detecting an external stimulus in rhythmic hop for the back kick showed significantly different response times. Conclusively, rhythmic hop is recommendable for the purpose of kicking velocity, but not for the purpose of response time. Athletes should be careful in executing rhythmic hop as their preparatory motions for the back kick, since the response time could be shortened or lengthened according to the instant of detecting an external stimulus.

• Journal of Fisheries and Marine Sciences Education
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• v.26 no.6
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• pp.1201-1208
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• 2014

The purpose of this study was to analyze the movements of the lower extremity muscle activities during a taekwondo kick motion called 'Balbutyeo Naeryeochagi', which was administered to players to improve their posture and muscle activity. Eight professional players and Eight amateur players were recruited as the subjects. Kinematic data were collected by EMG equipment, and the rectus femoris, tibialis anterior, biceps femoris, and medial gastrocnemius were measured using this instruments. This study processed the data using the Windows SPSS Ver. 18.0 to get an independent t-test, with the setting, p<.05. During the 'Balbutyeo Naeryeochagi' kick motion, there were small and inconsistent effects on each part. Results indicated that rectus femoris, tibialis anterior between two groups showed significantly difference in P1 and P2. Biceps femoris muscle activity in P2 showed large values in amateur group, and gastrocnemius showed no significantly difference between professional and amateur player during 'Balbutyeo Naeryeochagi' kick motion.

• International Journal of Internet, Broadcasting and Communication
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• v.15 no.1
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• pp.222-230
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• 2023

The purpose of this study is to provide basic data on sports entertainment programs by collecting data on unstructured data generated by Naver and Google for SBS entertainment program 'Women Who Score Goal', which began regular broadcast in June 2021, and analyzing public perceptions through data mining, semantic matrix, and CONCOR analysis. Data collection was conducted using Textom, and 27,911 cases of data accumulated for 16 months from June 16, 2021 to October 15, 2022. For the collected data, 80 key keywords related to 'Kick a Goal' were derived through simple frequency and TF-IDF analysis through data mining. Semantic network analysis was conducted to analyze the relationship between the top 80 keywords analyzed through this process. The centrality was derived through the UCINET 6.0 program using NetDraw of UCINET 6.0, understanding the characteristics of the network, and visualizing the connection relationship between keywords to express it clearly. CONCOR analysis was conducted to derive a cluster of words with similar characteristics based on the semantic network. As a result of the analysis, it was analyzed as a 'program' cluster related to the broadcast content of 'Kick a Goal' and a 'Soccer' cluster, a sports event of 'Kick a Goal'. In addition to the scenes about the game of the cast, it was analyzed as an 'Everyday Life' cluster about training and daily life, and a cluster about 'Broadcast Manipulation' that disappointed viewers with manipulation of the game content.

• Korean Journal of Applied Biomechanics
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• v.18 no.1
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• pp.117-127
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• 2008

The purpose of this study was to investigate the relationship between research of mechanical friction and Taekwondo kick performance. For this a Taekwondo kick performance test, A.F.T.S.(Automated Footwear Testing System) and survey about fitting was used. There was a statistically significant difference between all the Taekwondo shoe types. While performing the roundhouse kick there were statistically significant differences in the peak free moment(p=.01) and peak plantar pressure between type A and B. Comfort testing revealed that there were statistically significant difference between type A and B in the five comfort variables tested but not between type B and Type C. There was statistically significant differences between each of the Taekwondo shoes but there was no relationship between the performance and the results of the survey.

• Aerospace Engineering and Technology
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• v.5 no.2
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• pp.159-165
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• 2006

In this study, structural analysis is executed about cone structure of KSL V-1 2nd stage KMS(kick motor support structure) which is designed for support the load developed from 2nd stage kick motor. KMS is consisted of cone structure and truss structure which is designed for supporting load developed from 2nd stage payload. Applied loads to cone structure are tension load by inertia developed from kick motor and compression load developed from kick motor. Also, shear and bending load are developed according to flight condition. In this study, structural analysis of cone structure is executed under several load condition which may be applied to cone structure. Also, structural analysis with two finite element model is performed according to pressure vent scheme. In result of structural analysis, critical load condition is equivalent tension load with cut-out.

• Aerospace Engineering and Technology
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• v.9 no.2
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• pp.138-142
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• 2010

The thrust axis alignment of the launch vehicle is very important because of the misalignment causes the unstable attitude control and results in mission failure. Generally, optical methods such as digital theodolite and laser tracker and mechanical method such as turn table method are used to align thrust axis to vehicle axis. This article deals with the simple method of thrust axis alignment of Kick Motor.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1991.11a
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• pp.171-179
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• 1991

This paper refers to the results of a study on the usefulness of simulation techniques based on both modeling and experiments of KICK DOWN pressure control circuit using an duty solenoid valve controlled by pulse width modulation for an automatic transmission. In this study, dynamic characteristics of solenoid valve plunger and first pressure are verified. Besides, this paper shows the design data for improvement of feeling in changing of gear by means of simulation according to varying the size of jet orifice and temperature of automatic transmission fluid, which are the important variables of the first pressure.

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.7
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• pp.683-687
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• 2009

Track jump control is a random access strategy for short distance movement. The most common track jump scheme is a bang-bang control of a kick and brake manner. In a conventional track jump scheme, a track-following compensator is turned off during kick and brake periods, and restarted at a target track for track pull-in. The inevitable controller switching with non-zero initial condition results in undesirable transient response, and excessive overshoot in the transient response causes track pull-in failure. In this paper, a new track jump scheme is proposed for enhancing track jump stability. Instead of control switching, internal states of a track-following controller are artificially manipulated for kick and brake actions in a digital control environment. Experimental results are provided in comparison with conventional track jumps.

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.707-710
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• 2008

The method suggested in this thesis is the safe and economic method when testing rocket engine because ground test facility copies high altitude. We have decided to use the schematic of testing facility based on already known design method and test result, and we have decided the test condition for ground firing test of solid fuel. In addition the pressure of nozzle exit area is 0.1bar, we have designed the testing facility structure to test in this condition. Moreover, we have designed to reduce the accident probability.

• Journal of Korean Orthopaedic Sports Medicine
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• v.3 no.1
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• pp.42-48
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• 2004

The Football, popular spots in korea, increasing population to participate club activity caused various injuries with the consequence. Investigating relationship between biomechanics of the skills using football and injuries, we propose helpful methods to prevent injuries. Also authors point out the differences between outdoor and indoor football and women's football, and study skills using football like kick, pass, heading and head injury with researching literatures.