• Korean Journal of Applied Biomechanics
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• v.19 no.3
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• pp.467-479
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• 2009

The purpose of this study was to present the quantitative data which riders can utilize teaching field by comparison analysis of kinematics according to skill level of rider during 2 strides rising trot with the JeJu's-Horse. Participated subjects was consisted of total 10 riders(unskilled: n=5, skilled: n=5). The method of experiment & analysis was based on 3D cinematography. Variables were consisted of temporal, linear & angular kinematics by each event & phase. The skilled assigned more ratio of elapsed time in air than support phase, had the less range of motion in up-down direction and more consistent velocity in lateral & forward direction and performed periodic up-down movement with alignment in vertical direction according to elapsing of phases. The skilled more flexed at elbow and extended backwardly according to elapsing of phases, while more flexed forwardly at hip & knee and plantarflexion at ankle. The skilled postured backward extension but the unskilled do forward flexion. That is, It was considered that the unskilled continued more unstable posture than the skilled during 2 strides in rising trot.

• Proceedings of the KIEE Conference
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• summer
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• pp.117-119
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• 2004

An optimal flight motion simulator path generation method is proposed for hardware in the loop simulation of high maneuverable missile. The proposed method consists of open loop and closed loop path calculation algorithm based on the energy optimal control strategies. The optimal angle command is able to protect the simulator from high acceleration shock at initial control phase.

• The Bimonthly Magazine for Agrochemicals and Plant Protection
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• v.2 no.7
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• pp.57-59
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• 1981

응애의 천적인 딱정벌레가 유기염소제인 DDT와 BHC에 의하여 전멸된 이후 응애피해가 급진적으로 창궐하여 과수류를 비롯해 채소, 산림에 이르기까지 많은 피해를 입혀 농민을 우울하게 만들었고 그 방제도 무척 어려워 악성 해충의 으뜸을 차지하고 있다. 그러나 우리가 조금만 더 세밀한 관심을 갖고 약제를 사용한다면 경제손실을 최대한 막을 수 있으므로 과학영농하는 자세로 적정약제를 교대로 살포, 증산에 이바지 해야겠다.

• Fashion & Textile Research Journal
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• v.15 no.6
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• pp.1000-1009
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• 2013

Well-fitting riding breeches provide a comfortable ride. Horse-riding breeches should fit the lower body with patches located on the inside of hip and knees to prevent tears and slips. This study provides information about the fit of women's breeches using 3D human body scan data wearing commercially available two breeches according to posture. To get information about breeches fit, we measured the angle of waist line, the length, and the area of the breeches fit on four 20's women. This research showed the problem which was down for waist back line in the case of the horseback riding pose. The back waistline of the riding breeches should be raised compared to the front waistline; subsequently, an increased waistline angle results in less back waistline decrease. The breeches have plenty of length from back waist to crotch so the breech fit can be improved. The thigh circumference increased when riding in the front; therefore, good elasticity of the weft direction of the fabric is recommended. The length increase and the peripheral increase of the front knee significantly increased the surface area of the knee; consequently, knee patch material should be a two-way elastic fabric in all directions to enhance comfort according to riding motion.

• Korean Journal of Applied Biomechanics
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• v.22 no.1
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• pp.83-94
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• 2012

The purpose of this study was to analyse the effect of posture correction & stabilization according to horse rider's(n=10) skill levels of novice(0wk), mid-skill(12wk) & skill(24wk) in walk & trot. First, Mean posture of 3 times experiments; Anterior & posterior leaning posture of trunk showed rather unstable according to progress of the stages of TD1, TO, TD2 phase, and also shoulder & elbow angle, which effects to the distance from bit to rein, showed unstable riding posture. There was close relationship between shoulder and elbow Angle in walk and hip, knee & ankle angle in trot. Second, Posture correction & stabilization according to riding skill levels; Anterior & posterior leaning posture of trunk did not show significant difference statistically but showed approaching tendency to trunk's vertical line and showed significant difference(p<.05) according to improvement of skill levels in walk & trot horse riding. Hip angle showed significant difference according to progress of the stages of TD1, TO, TD2 phase(p<.05) and showed tendency maintaining the larger thigh flexion according to improvement of skill levels in walk & trot. Knee angle showed more stable posture by maintaining the larger flexion between thigh and shank according to improvement of skill levels in walk & trot(p<.05). Ankle angle also showed tendency maintaining the larger plantar flexion of foot according to improvement of skill levels in walk & trot. When considering the above, regular horse riding program could be useful in posture correction & stabilization according to improvement of skill levels of novice(0wk), mid-skill(12wk) & skill(24wk) in walk & trot.

• Korean Journal of Applied Biomechanics
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• v.25 no.3
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• pp.335-342
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• 2015

Objective : The purposes of this study was to analyze the effects of the stirrup length fitted to the rider's lower limb length and it's impact on less skilled riders during trot in equestrian events. Methods : Participants selected as subjects consisted of less skilled riders(n=5, mean age: $40.02{\pm}10.75yrs$, mean heights: $169.77{\pm}2.08cm$, mean body weights: $67.65{\pm}7.76kg$, lower limb lengths: $97.26{\pm}2.35cm$, mean horse heights: $164.00{\pm}5.74cm$ with 2 type of stirrups lengths(lower limb ratio 74.04%, and 79.18%) during trot. The variables analyzed consisted of the displacement for Y axis and Z axis(head, and center of mass[COM]) with asymmetric index, trunk front-rear angle(consistency index), lower limb joint(Right hip, knee, and ankle), and average vertical forces of horse rider during 1 stride in trot. The 4 camcorder(HDR-HC7/HDV 1080i, Spony Corp, Japan) was used to capture horse riding motion at a rate of 60 frames/sec. Raw data was collected from Kwon3D XP motion analysis package ver 4.0 program(Visol, Korea) during trot. Results : The movements and asymmetric index didn't show significant difference at head and COM, Also, 74.04% stirrups lengths in trunk tilting angle showed significant difference with higher consistency than that of 79.18% stirrups lengths. Hip and knee joint angle showed significant difference with more extended posture than that of 74.04% stirrups lengths during trot. Ankle angle of 79.18% stirrups length showed more plantarflexion than that of 74.04% stirrups lengths. Average vertical force of rider showed significant difference with higher force at 79.18% stirrups lengths than that of 74.04% stirrups lengths during stance phase. Conclusion : When considering the above, 74.04% stirrups length could be effective in impulse reduction with consistent posture in rather less skilled horse riders.

• Korean Journal of Applied Biomechanics
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• v.24 no.4
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• pp.329-338
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• 2014

The purpose of this study was to analyze of the rider postural alignments according to the fitting of stirrups lengths during walk of high level riders. Participants selected as subject were consisted of horse riders of high level (age: $47.66{\pm}3.51yrs$, height: $168.40{\pm}4.84cm$, body weight: $73.36{\pm}15.58kg$, low extremity length: $94.76{\pm}3.98cm$, career: $23.33{\pm}5.77yrs$) and walk with 3 types of stirrup lengths(ratio of low extremity 68.04%, 73.25%, 78.48%). The variables analyzed were consisted of the displacement of Y axis (center of mass, head, thigh, shank and foot), FR angle, LR angle, dynamic postural stability index (DPSI), coefficient of variation (CV%), and distance (X axis) of low extremity limb between right and left. The displacement of Y axis in COM, thigh, shank, foot limbs were not statistically significant, but movements of head showed greater distance of B type and C type than that of A type during 1 stride of walk. The FR and LR angle in trunk of horse rider, dynamic postural stability index and, coefficient of variation didn't show significant difference statistically according to the fitting of stirrup lengths. Also the distance (X axis) of low extremity in thigh and shank didn't show significant difference statistically in between right and left, but right and left foot showed greater distance in C type than that of B and A types during walk in horse back riding. The hip and ankle joint angle not statistically significant according to stirrups lengths, But knee joint angle showed more extended according to the increase of stirrups lengths during stance and swing phase in walk.