• 한국기계기술학회지
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• 제13권1호
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• pp.65-71
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• 2011

Steering gear is the part of an automobile that change circular movement of steering wheel to lateral movement of rack to change driving direction. This can be classified with manual and power steering gear. Manual steering gear is operated only with human power while power steering gear use oil pressure support. These days power steering gear is more common to almost of the car. Recently a korean company manufactures a speed sensitive power steering which provide variable steering feel depend on the speed of car. The Broens company of Australia produces and exports the test equipments for the manufacture of power steering valves and assemblies to major vehicle manufactures. Some korean companies imported the test equipments from Australia, thus increasing the cost. The purpose of this study is development of the valve balance test equipment to measure the valve torque of the power steering gear. This study designed and manufactured the valve balance test equipment to take hold of the power steering valve using CAE analysis. In order to evaluate the performance of the developed valve balance test equipment, the R&R tests have been conducted.

• The Journal of Korean Physical Therapy
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• 제17권4호
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• pp.537-557
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• 2005

The purpose of this study was to investigate the effect of pelvic traction and muscle energy technique(MET) for hemiplegic patients on static standing balance. The scale for static standing balance is measured by using mean balance(%), frequence(Hz), sway area($mm^2$), sway path(mm), max sway velocity(mm/s), ant/post sway angle($^{\circ}$), lateral sway angle($^{\circ}$), sway number, change of pelvic height is measured in relation to the height of ASIS and PSIS. The subjects of this study were thirty hemiplegic patients: 15men and 15 women, with an average ages of 50.80 years. The thirty subjects were divided into 3 group of 10 at random ; ten subjects had pelvic traction after bobath therapy (the pelvic traction group), ten subjects had muscle energy technique after bobath therapy (the MET group), and ten subjects had only bobath therapy (the control group). Static standing balance was measured using BPM (balance performance monitor; data print software version 5.3), pelvic height was measured using height measuring with an adjustable horizontal arm. In order to assure the statistical significant of the result, an one-way ANOVA, the paired t-test, and a person's correlation were applied at the.05 level of significance. The results of this study were as follows: 1) The change in pelvic height were statistically significant between the pelvic traction group, the MET group and the control group on pre-treatment and post-treatment(p<.05). 2) The change in affected and non-affected on weight bearing were not statistically significant between the pelvic traction group, the MET group and the control group on pre-treatment and post-treatment(p>.05). 3) The change in frequency were statistically significant between the MET group, the control group and the pelvic traction group on pre-treatment and post-treatment(p<.05). 4) The change in sway area were statistically significant between the MET group, the control group and the pelvic traction group on pre-treatment and post-treatment(p<.05). 5) The change in sway pa1h were statistically significant between the pelvic traction group, the MET group and the control group on pre-treatment and post-treatment(p<.05). 6) The change in max sway velocity were statistically significant between the pelvic traction group, the MET group and the control group on pre-treatment and post-treatment(p<.05). 7) The change in ant/post sway angle were statistically significant between the pelvic traction group, the MET group and the control group on pre-treatment and post-treatment(p<.05). 8) The change in lateral sway angle were statistically significant between the pelvic traction group, the MET group and the control group on pre-treatment and post-treatment(p<.05). 9) The change in sway number were statistically significant between the pelvic traction group, the MET group and the control group on pre-treatment and post-treatment(p<.05). In conclusion, there was a difference between the experimental group and the control group. In the future, we have to study continuously about pelvic traction and muscle energy technique in hemiplegic patients.

• 대한물리치료과학회지
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• 제18권2호
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• pp.73-80
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• 2011

Purpose: The purpose of this study was to investigate the correlation between the visual perception ability and the static dynamic balance ability in health elderly. Method: The Motor Free Visual Perception Test-Row Score(MVPT-RS) and MVPT-Process Time(MVPT-PT) were used for evaluating the visual perception abilities. Assessment of the balance ability was taken by using Good Balance System. In the assessment using Good Balance System, X, Y coordinate speed, anterior-posterior direction, medial-lateral direction and Velocity Movement(VM) in standing posture when eye open were measured as static balance abilities. Thirty-seven healthy elderly who live in Gwangyang participated in the experiment for 2 months, from October to November 2010. Results: 1. There were statistically significant differences of MVPT-RS, MVPT-PT, NSB-X, NSB-Y, NSB-VM, OLB-X, and OLB-VM based on the gender(p<0.05). 2. The negative correlations of MVPT-RS:NSB-Y(r=-0.354), MVPT-RS:OLB-X(r=-0.4), MVPT-RS: OLB-Y(r=-0.371), but positive correlations of MVPT-PT:DTB-T showed a statistical significance(r=0.45, p<0.05). 3. The positive correlations of NSB-X:NSB-Y(r=0.54), NSB-X: NSB-VM(r=0.848), NSB-Y:NSB-VM(r=0.531), OLB-X:OLB-Y(r=0.876), OLB-X:OLB-VM(r=0.872), and OLB-Y:OLB-VM(r=0.787) showed statistical significances(p<0.05). Conclusion: These results showed that the visual perception ability was correlated with some balance ability in health elderly. Especially the perception test process time(MVPT-PT) has closely related with the DTB-T. The visual perception ability is considered as a factor on the balance ability in health elderly. Further study will focus on the development of improving program of visual perception ability as an improving method of balancing ability in health elderly.

• 한국항공운항학회지
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• 제24권2호
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• pp.19-24
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• 2016

Positional stability analysis based on aerodynamic forces and induced moments of formation flight using two small aircraft models is presented. The aerodynamic force and moments of the trailing aircraft are analyzed in the aspect of flight stability. The induced moments with the change of local flow direction by wing-tip vortex from the leading aircraft can affect the flight positional stability of aircraft in closed formation flight. Aerodynamic forces and moments of trailing aircraft model are measured by 6-component internal balance at the 49 locations with vertical and lateral space between two aircraft models. Results are shown that the positional stability of trailing aircraft in formation flight can be analyzed by positional stability derivatives with vertical and lateral space. It is concluded that flying positions can be important factors for aircraft position stability due to induced aerodynamic force and moments with vertical and lateral spacing by the variation of flow pattern from the leading aircraft in formation flight.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 추계 학술발표회 제20권2호
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• pp.201-204
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• 2008

FRP 합성재료로 구속된 콘크리트의 응력-변형률 응답을 합리적으로 예측할 수 있는 해석모델이 제시되었다. 제안된 모델은 하중이 증가함에 따라 점진적으로 발생하는 미세균열에 의한 부피팽창이 미세재료구조의 손상을 나타내는 중요한 척도이며, 이에 손상정도에 따라 하중지지능력을 일관되게 산정할 수 있다는 기본개념에 근거한다. 이를 위하여 제안모델은 면적변형률 및 공극의 함수로 표시된 탄성계수, 팽창콘크리트와 구속매체의 상호작용을 나타내는 에너지 평형식, 변화하는 구속력 및 점증계산논리를 포함한다. 따라서 실험으로부터 유도된 팽창비 관계식으로부터 횡방향 혹은 부피팽창변형률을 산정하는 기존의 해석모델과는 달리 역학적 거동 및 에너지 평형식으로부터 연속적으로 변화하는 횡방향 변형률을 산정한다.

• 한국정밀공학회지
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• 제22권11호
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• pp.111-117
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• 2005

The vibration problems associated with gear coupled rotors have been the focus of much engineering work. These systems are complex and difficult to analyze in that they have the problems associated with conventional rotors plus those additional problems associated with the gear couplings. This paper examines the problems peculiar to the gear mesh. Because of the meshing action of gears, the elasticity of the gear teeth introduces time-varying stiffness coefficients into the governing equations of motion. This means that system response must be thought of in terms of Mathieu-type equations, where multiple-frequency response occur due to the periodic coefficients. The meshing action of the gears also couples the lateral and torsional gear motions. Gear errors, such as tooth profile and spacing errors, produce forces and torque that excite the system at multiple frequencies, some of which are much higher than shaft rotational speed. To investigate how to the time-varying stiffness in the gear teeth and the gear errors act one the dynamic response of the gear coupled rotors, a three-dimensional dynamic model with lateral-tortional oscillation is developed. The harmonic balance technique is employed to solve this mathieu-type problem.

• 대한물리의학회지
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• 제13권4호
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• pp.35-42
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• 2018

PURPOSE: This study was conducted to investigate the effects of Kinesio taping and massage application to the calf muscles on ankle stability. METHODS: The study subjects were 66 healthy adults (male: 32, female: 34) who had no instability in their ankles. Subjects were randomly assigned to a Kinesio taping group or a massage group. The research tool used the Y-balance test to measure instability of the ankle. The distance between the right and left foot was measured from the center in the anterior, posterior-medial, and posterior-lateral directions. Massage was applied to the calf muscles three times over two weeks and Kinesio tape was attached to the calf muscle and tibialis anterior for 10 hours twice during the experimental period. RESULTS: The results showed that application of Kinesio taping resulted in increases in the distance between the feet increased in some directions. After the massage, the distance extended from the anterior and posterior-lateral directions was prolonged, and the ankle stability on the right and left sides was partially improved by massage application. CONCLUSION: Kinesio taping and massage applied to the calf muscles are appropriate interventions for the improvement of ankle stability. Based on the application times of massage, Kinesio taping appears to work more effectively for ankle stability.

• 대한물리의학회지
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• 제9권4호
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• pp.355-361
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• 2014

PURPOSE: The purpose of this study was to determine the immediate effect of low-dye taping on balance performance in subjects with flexible flatfoot. METHODS: Fifteen asymptomatic volunteers who had flexible flatfoot (age, $21.7{\pm}1.81$years; height, $164.80{\pm}7.57cm$; weight, $56.47{\pm}10.48kg$) were participated for this study. Navicular drop test was used to evaluate pronation of foot in three different conditions; non-weight bearing position without low-dye taping, weight bearing position without low-dye taping, weight bearing position with low-dye taping. And balance performance (anterio/ posterior, medial/lateral, and overall) was evaluated using the Biodex Balance System in three different conditions; one-leg standing without low-dye taping, one-leg standing with low-dye taping, and one-leg standing with low-dye taping in one week later. Repeated-measures analysis of variance (ANOVA) was used to assess navicular height and balance performance across the three testing conditions. RESULTS: Significant and clinically meaningful improvement in navicular height was found after application of the low-dye taping. However, there was no statistically significant change in balance performance. CONCLUSION: The results of this study provide evidence to suggest that low-dye taping does not affect balance performance.

• 한국콘텐츠학회논문지
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• 제10권9호
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• pp.285-292
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• 2010

본 연구는 8방향 경사와 회전운동이 만성요통환자의 통증과 동적균형에 미치는 영향을 알아보고자 시행되었다. 20명의 만성요통환자가 실험에 참여하였다. 10명(실험군)은 물리치료기구[온열팩{Hot Pack(H/P), 경피신경자극{Transcutaneous Electric Nerve Stimulation(TENS)}, 초음파{Ultra Sound(U/S)}]를 이용한 치료를 받은 후에 8방향 경사와 회전운동을 실시하였고 나머지 10명(대조군)은 물리치료기구를 이용한 치료만 실시되었다. 치료 중재는 주 3회, 6주 동안 적용되었다. 동적균형과 통증은 Star Excursion Balance Test(SEBT)과 Visual Analog Scale(VAS)를 이용하여 측정하였다. VAS 점수는 두 그룹 모두 감소하였으나 실험군에서 보다 유의하게 감소하였다. 동적균형 능력 또한 실험군에서 보다 유의한 증가를 나타내었다. 따라서 8방향 경사와 회전운동은 만성요통환자의 통증과 동적균형에 효과가 있었다고 사료된다.

• The Journal of Korean Physical Therapy
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• 제27권4호
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• pp.221-227
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• 2015

Purpose: The purpose of this study was to examine the impact of gluteus medius (GM) strengthening training using the pressure biofeedback unit for lower extremity muscle function and balance ability in stroke patients. Methods: Twenty-seven stroke patients (14 men, 13 women) volunteered to participate in this study. They were randomly assigned to 3 groups: pressure biofeedback unit GM training, general GM training, and control group. Experimental group 1 performed GM strengthening training using PBU in the sidelying position. Experimental group 2 performed GM strengthening training without PBU in the sidelying position. The training program lasted 4 weeks (20-minute sessions, three times a week). Muscle function was assessed by measuring muscle strength and endurance, and Berg balance scale (BBS), Lateral Reach Test (LRT), and limited of stability (LOS) velocity were measured for evaluation of balance ability. Results: Enhancement of muscle strength and endurance was significantly higher in experimental group 1 than in the other two groups (p<0.05). In comparison of the balance function, experimental group 1 showed a significantly enhanced ability to balance (p<0.05). After the intervention, experimental group 1 showed a significant reduction of LOS velocity in the anterior direction and affected direction (p<0.05). There was no significant difference than the other two groups but a large reduction was observed. Conclusion: These findings suggest that selective gluteus medius strengthening training using the pressure biofeedback unit is effective for lower extremity muscle function and balance ability in stroke patients.