• Korean Journal of Applied Biomechanics
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• v.21 no.2
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• pp.161-171
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• 2011

The purpose of this study was to identify biomechanical characteristics of glide and delivery motion of In-Sung Hwang, player who is a member of the national team among the finalists in the men's shot put at the 2010 National Sports Festivals. Three-Dimensional motion analysis using a system of 3 video cameras at a sampling frequency of 60 Hz was performed for this study. During the glide and delivery phase the results showed following characteristics; 1) The glide type was suitable for the short-long technique, but the trajectory of shot at the glide and delivery phase showed a different trajectory pattern with "S-shaped" type of elite players due to many deviating from central axis of the APSS(athletic-plus shot system). 2) Left knee was more flexed during failed trials compared to successful trials but COG was higher. Therefore, the player showed less stability of COG as he may not get enough breaking force at the left foot. 3) Furthermore, it would be required to have strong muscle power at the trunk, throwing arm, and the lower extremity in order to achieve maintain a low projection angle of the release.

• The Journal of Korean Physical Therapy
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• v.18 no.1
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• pp.33-40
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• 2006

Purpose: The purpose of this study was to investigate the effects of cervical mobilization on the tension type headache recovery. : The subjects were consisted of 70 patients with tension type headache. All subjects randomly assigned to cervical mobilization group and massage group. The mobilization group received cervical mobilization with modality treatment and massage group received cervical massage with modality treatment. Visual analogue scala(VAS) was used to daily headache hours and patient's pain level. Results: The results of this study were summarized as follows: 1. The Visual Analogue Scale(VAS) was mobilization group showed significant1y decreased more than massage group(p<.01). 2. The daily headache was mobilization group showed significantly decreased more than massage group(p<.01). Conclusion: mobilization is beneficial treatment for tension type headache.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.18 no.3
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• pp.84-91
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• 2010

New aircraft category such as Light Sport Aircraft is introduced to prevent Ultralight Vehicle accidents and to promote aviation sports. Therefore, a new rule for airworthiness standard, certification, operation and maintenance of light sport aircraft is being created. The present study deals with LSA concept, development trend of LSA, airworthiness standards and certification policy. In particular, an aircraft type analysis of FAA certified LSA is conducted to establish performance requirements of Light Sport Aircraft designs.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.21 no.1
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• pp.57-61
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• 2013

In the present study, which is currently operating domestically and internationally, from the Technical Standards for Flight Safety of Light Sport Aircraft and certification system through a comparative analysis of the LSA Category Airworthiness Certifications documents. In particular, an aircraft type analysis of FAA certified S-LSA that the speed greater than 120 knots LSA manufactured without United States of America. Through the analysis, we presented a revised plan to activation of the domestic aviation leisure sports and the development of the Light Sport Aircraft industry in reality.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.5
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• pp.977-982
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• 2017

Recently, the effort that converge the sport and ICT continues together with developing ICT. The game is a representative example. The digital sport is developing as mixed type that are composed with sport and digital such as screen golf and screen bowling. The addiction problem exist in the digital sport like the addiction problem exist in general sport. In this paper, we propose the addiction model in the digital sport as fractional-order. We represent time series and phase portrait for nonlinear behavior from proposed fractional-order model and we confirms the difference between them.

• Korean Journal of Applied Biomechanics
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• v.30 no.1
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• pp.1-6
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• 2020

Objective: The incidence rate of elbow ulnar collateral ligament injuries is dependent on the throwing speed or pitching type, especially in adolescent baseball players. However, mixed results have been reported due to a lack of controlled biomechanical analysis. Thus, the purpose of this study was to investigate the biomechanical analysis of the elbow in relation to throwing speed and pitching type. Method: Four overhead type high-school baseball players were recruited for this study. The participants were asked to throw balls with different types of pitch and speed. While the throwing speeds were measured, each pitching moment of the elbow was recorded. Descriptive statistics, frequency analysis, mean comparison analysis, and Pearson's correlation analysis were performed in order to examine differences in peak varus and valgus moment during pitching motion in the elbow in all throwing speed and pitching types. Results: There was no significant difference in physical characteristics, throwing speed, and momentum variability among all players. The mean varus moments were 44.38±1.55 Nm, 48.83±1.66 Nm, and 48.94±0.95 Nm, and the moment gaps between varus and valgus were 7.36±3.25 Nm, 7.44±2.02 Nm, and 7.36±2.62 Nm in fastball, curveball, and slider ball, respectively. The varus moment was higher in the curved and slider balls than in the fastballs, and there was no significant differences between the varus moments regarding the pitching type. However, the increase in valgus moment and decrease in moment gap according to throwing speed was significantly increased in the slider ball (r=0.718 and -0.591, respectively). Conclusion: The possibility of elbow injury caused by the valgus moment or moment gapincreases more rapidly in slider balls as the speed increases. Based on our results, appropriate pitching guidelines should be suggested to prevent ulnarligament injuries, especially in adolescent baseball players.

• Korean Journal of Applied Biomechanics
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• v.25 no.4
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• pp.489-498
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• 2015

Objective : The purpose of this study was to analyze the effects of the windlass mechanism in trail-walking shoe prototypes that can effectively support arches. A study of these effects should help with the development of a first-rate trail-walking shoe development guide for the distribution of quality information to consumers. Methods : The subjects were ten adult males who volunteered to participate in the study. Shoes from three companies, which will be referred to as Company S (Type A), Company M (Type B), and Company P (Type C), were selected for the experiment. The subjects wore these shoes and walked at a speed of 4.2 km/h, and as they tested each shoe, the contact area, maximum pressure average, and surface force were all measured. Results : Shoe Type A showed a contact area of $148.78{\pm}4.31cm^2$, Type B showed an area of $145.74{\pm}4.1cm^2$, and Type C showed an area of $143.37{\pm}4.57cm^2$ (p<.01). Shoe Type A demonstrated a maximum average pressure of $80.80{\pm}9.92kPa$, Type B an average of $85.72{\pm}11.01kPa$, and Type C an average of $89.12{\pm}10.88bkPa$ (p<.05). Shoe Type A showed a ground reaction force of $1.13{\pm}0.06%BW$, Type B a force of $1.16{\pm}0.04%BW$, and Type C a force of $1.16{\pm}0.03%BW$ (p<.05). Conclusion : The Type A trail-walking shoe, which was designed with a wide arch from the center of the forefoot to the front of the rearfoot showed excellent performance, however, more development and analysis of the windlass mechanism for a variety of arch structures is still necessary.

• Korean Journal of Applied Biomechanics
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• v.25 no.4
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• pp.465-474
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• 2015

Objective : A study and development of Korean Bobsleigh athletes's shoe which considers their physical condition has yet to be completed. So this study examines the effects of running shoes used by athletes based on plantar pressure and sprint time in order to provide raw data for the development of bobsleigh shoes suitable for Koreans. Method : The study selected seven bobsleigh athletes as subjects and selected three pairs of spiked running shoes from three companies, which will be referred to as Company N (Type A), Company A (Type B), and Company M (Type C). To analyze sprint time and plantar pressure for each shoe, the subject of the study were instructed to wear the selected shoes and to drag a sled at maximum sprint for 15 meters for 15 meters for in each condition that would be in real bobsleigh competitions. Results : The average sprint intervals for each athlete in each pair of shoes revealed Type C produce the fastest sprint in the order of Type C < Type A< Type B. Shoe Type C also had the largest contact area in order of Type C > Type B > Type A (p<.01). None of the three shoe types seem to yield a distinct advantage in terms of maximum average pressure or maximum pressure. Conclusion : In the future, functional analysis should be carried out by comparing the material properties, hardness, and toe spring of shoes based on the Type C shoe from Company M in order to develop bobsleigh shoes suitable for Koreans.

• Korean Journal of Applied Biomechanics
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• v.17 no.3
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• pp.165-172
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• 2007

The purpose of this study was to examine the effects of the result of hardship performance of the propulsion speed on the flying carmel spins during a Figure Skating. The subjects were five the korea national representative players. Kinematic variables were analyzed 5frame of the excursion phase by the three-dimensional motion analysis system(60Hz). The obtained conclusion were as follows: In this study, during the propulsion classify two groups as "type I" the acceleration patterns S3, S4 and "type II" the uniform velocity group S1, S2, S5. The results of percentage comparative analysis between type I and type II can be summarized as below: the height of jump(24%), the height of COM(25%), the maximum speed of Roundhouse Kick(21%), the judging technical score(18%), the flight time(13%), the velocity of spins(4%), the distance of flight(-6%) Analysis of the results on performance variables, the velocity pattern of the type I showed comparatively excellence than that of type II.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.1228-1231
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• 2004

We analyzed the impulse on 24 sensors location under the foot using the Parotec system for the investigation of the relationship between the shoe type and the foot pathologies. Total 7 kinds of shoes, i.e. sport shoe, high heel shoes (5cm heel, 8cm heel, 13cm heel), platform shoe, inline skate, and heelys were evaluated for 20 normal subjects. Compared with the impulse distribution of the sport shoe, greater impulses were shown at the 1$^{st}$ phalange and the 1$^{st}$ metatarsal-phalangeal head in high-heel shoes, lateral tarsal bone and medial metatarsal bone in platform shoe, medial tarsal bone in inline-skate, and medial tarsal bone and 1st phalange in heelys shoe. The result of this study is expected to provide useful information about the relationship between the shoe type and the foot pathologies.ies.