• Physical Therapy Rehabilitation Science
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• 제9권1호
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• pp.10-17
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• 2020

Objective: Hallux valgus (HV) is a common musculoskeletal deformity that is accompanied with pain and continues to decrease one's quality of life and ability to perform daily life activities by affecting gait and static stability. Therefore, this study aimed to investigate the effect of the angle of HV (HVA) and to compare the one-legged stance and gait parameters in young adults with less HV and severe HV. Design: Cross-sectional study. Methods: Forty young adults were divided into two groups, where HVA ≥15° (n=20) was defined as HV, and HVA <15° (n=20) was defined as normal. For balance ability, the center of pressure (COP) path, velocity, length of axis of the COP path, deviation of the x-axis and y-axis, and percentage of foot pressure were measured, and gait, the foot rotation angle, step length, percentage of each phase of the gait cycle, time change from the heel to forefoot, and maximum pressure of the forefoot and midfoot were measured. Results: Significant differences were found in sway length and time change from heel to forefoot during walking between the normal and HV groups (p<0.05). Most parameters were not associated with the HVA, but parameters such as length of axis and time to change from heel to forefoot were significantly associated with the HVA (p<0.05). Conclusions: These results suggest that most one-legged stance and gait parameters were not significantly affected by the HVA in young adults; therefore, future studies are needed in order to address other dynamic parameters and other methods of gait analysis for detecting clinically meaningful conditions.

• 대한기계학회논문집A
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• 제37권1호
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• pp.97-103
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• 2013

본 연구는 원추대 가공과 등가인 동시 5 축 구동을 통한 볼바 측정용 경로 생성 기법을 소개하며 시스템 구조 형태(Structural configuration)에 관계없이 모든 5 축 공작기계에 대해 적용 가능한 일반화된 방법을 제시한다. 5 축 공작기계 시스템 정보와 원추형 정보, 그리고 볼바 측정 정보 등을 입력 받아 NC 코드 생성, 다양한 오차 평가 시뮬레이션 및 측정 시험을 쉽게 수행할 수 있도록 원호 경로 생성에 필요한 수학적 기계 입력 모델을 제시한다. 또한 제시된 원추형 경로 모델을 토대로 5 축 동시 구동 시 회전축의 이송 범위를 수학적으로 검토하며 반꼭지각 및 기울기각의 크기 차이, 볼바 틸팅 허용각 및 워크피스 볼의 오프셋 위치 등 여러 가지 조건이 이송 범위에 미치는 영향에 대해 분석한다.

• Clinics in Shoulder and Elbow
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• 제21권4호
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• pp.179-185
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• 2018

Background: We analyzed the angle between the glenoid anterior surface and glenoid axis, the range of the glenoid apex and the location of the glenoid apex for assistance during shoulder surgery. Methods: Sixty-two patients underwent a computed tomography of the shoulder with a proximal humerus fracture. In the range of the glenoid apex, the ratios of the distribution of triangles with a Constant anterior and posterior area of the glenoid were measured. The location of glenoid apex was confirmed as the percentage of the position with respect to the upper part of the glenoid with the center of the part, analyzed the angle between the glenoid anterior surface and glenoid axis was measured. Results: The angle between the glenoid anterior surface and glenoid axis was $19.80^{\circ}{\pm}3.88^{\circ}$. The location of the glenoid apex is $60.36%{\pm}9.31%$, with the upper end of the glenoid as the reference. The range of the glenoid apex was $21.16%{\pm}4.98%$. When the height of the glenoid becomes smaller, the range of the glenoid apex tends to become larger (p=0.001) and the range of the glenoid apex becomes wider (p=0.001) as the glenoid width narrows. Conclusions: We believe the anatomical measurements of the glenoid will be helpful for a more accurate insertion in glenoid component. It is thought that more accurate insertion is possible if we can set other anatomical measurements using computed tomography imaging of the glenoid which can develop into the study of other anatomical measurements.

• 한국산학기술학회논문지
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• 제21권7호
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• pp.212-217
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• 2020

태양광 발전 시스템은 태양광 패널을 통해 발전된 전력을 계통연계를 통해 전송하는 종합 시스템이다. 발전량을 증대시키는 기술로써 태양광 입사각을 변화시켜 발전량을 증대시키는 추적식 태양광 발전장치 기술이 있다. 본 논문은 입사각을 변화시켜 발전량을 증대시키는 단축 추적식 태양광 발전장치의 구조물과 제어에 관한 연구이다. 핵심 내용은 태양광 구조물이 남북축을 중심으로 동서 방향으로 축회전하도록 구성한 단축 제어장치 및 기술이다. 일출로부터 일몰까지 동서방향으로 태양을 추종하는 태양광 구조물은 구조적 안정성과 태양광 추종 제어 성능 확보가 필요하다. 단축 추적 발전장치는 최대 25% 이상의 발전량 증대를 기대할 수 있다.

• 한국운동역학회지
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• 제15권4호
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• pp.13-24
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• 2005

The purpose of this study was to compare kinematic data between experts and novices, and identify difference kinematic parameters changing direction to kick in penalty kick of soccer play. Novice subjects were 5 high school students Who has never been experienced a soccer player, and expert subjects were 5 competitive high school soccer players. The 3-d angle was calculated by Euler's Angle by inertial axis and local axis with three-dimensional cinematography. Kinematic parameters in this study consisted of angles of knee joints, hip joints, lower trunk and upper trunk when the support foot was contacted on ground and kicking foot impacted the ball. The difference of angle of knee joints in the flexion/extension was insignificantly showed below $4{\sim}9^{\circ}$ in groups and directions of ball at the time of support and impact. But the difference of angle of hip joint was significant in groups and directions of ball at the time of support and impact. Specially the right hip joint of experts were more flexed about $12^{\circ}$($43.99{\pm}6.17^{\circ}$ at left side, $31.87{\pm}4.49^{\circ}$ at right side), less abducted about $10^{\circ}$ ($-31.27{\pm}4.49^{\circ}$ at left side, $-41.97{\pm}6.67^{\circ}$ at right side) at impact when they kicked a ball to the left side of goalpost. The difference of amplitude angle in the trunk was significantly shown at upper trunk not lower trunk. The upper trunk was external rotated about $30^{\circ}$ (novice' angle was $-16.3{\pm}17.08^{\circ}$, expert's angle was $-43.73{\pm}12.79^{\circ}$) at impact. Therefore the significant difference of kinematic characteristics could be found at the right hip joint and the upper trunk at penalty kick depending on the direction of kicking.

• Computers and Concrete
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• 제29권1호
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• pp.31-45
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• 2022

Experimental and numerical simulation were used to investigate the effects of angle and number of T shape non-persistent crack on the shear behaviour of crack's bridge area under uniaxial compressive test. concrete samples with dimension of 150 mm×150 mm×40 mm were prepared. Within the specimen, T shape non-persistent notches were provided. 16 different configuration systems were prepared for T shape non-persistent crack based on two and three cracks. In these configurations, the length of cracks were taken as 4 cm and 2 cm based on the cracks configuration systems. The angle of larger crack related to horizontal axis was 0°, 30°, 60° and 90°. Similar to cracks configuration systems in the experimental tests, 28 models with different T shape non-persistent crack angle were prepared in numerical model. The length of cracks were taken as 4 cm and 2 cm based on the cracks configuration systems. The angle of larger crack related to horizontal axis was 0°, 15°, 30°, 45°, 60°, 75° and 90°. Tensile strength of concrete was 1 MPa. The axial load was applied to the model. Displacement loading rate was controlled to 0.005 mm/s. Results indicated that the failure process was significantly controled by the T shape non-persistent crack angle and crack number. The compressive strengths of the specimens were related to the fracture pattern and failure mechanism of the discontinuities. Furthermore, it was shown that the compressive behaviour of discontinuities is related to the number of the induced tensile cracks which are increased by increasing the crack number and crack angle. The strength of samples decreased by increasing the crack number. In addition, the failure pattern and failure strength are similar in both methods i.e. the experimental testing and the numerical simulation methods (PFC2D).

• KIEAE Journal
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• 제9권2호
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• pp.81-90
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• 2009

Relating to grasping sequential landscape characteristics in consideration of the behavioral characteristics of the subject experiencing visual perception, this study was made on the subject of main walking line section for visitors of three treasures of Buddhist temples. Especially, as a method of obtaining data for grasping sequential visual perception landscape, the researcher employed [momentum sequential viewpoint setup] according to [the interval of pointers arbitrarily] and fisheye-lens-camera photography using the obtained omni-directional angle visual perception information. As a result, in terms of viewpoint selection, factors like approach road form, change in circulation axis, change in the ground surface level, appearance of objects, etc. were verified to make effect, and among these, approach road form and circulation axis change turned out to be the greatest influences. In addition, as a result of reviewing the effectiveness via the subjects, for the sake of qualitative evaluation of landscape components using the VR picture image obtained in the process of acquiring omni-directional angle visual perception information, a positive result over certain values was earned in terms of panoramic vision, scene reproduction, three-dimensional perspective, etc. This convinces us of the possibility to activate the qualitative evaluation of omni-directional angle picture information and the study of landscape through it henceforth.

• 한국광학회지
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• 제24권5호
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• pp.271-278
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• 2013

다층박막이 있는 기층에 단축이방성 배향막이 코팅되어 있을 때 비스듬히 입사한 빛의 유효반사계수 표현들을 유도하였다. 유효반사계수들과 타원상수들을 다층박막의 미지상수들은 물론 단축이방성 배향막의 광학이방성의 크기와 광축의 방향 그리고 배향막의 두께로 표현하였다. 이를 바탕으로 배향막의 정상굴절률과 이상굴절률, 배향된 두께 그리고 광축의 방위각과 기울임각을 다층박막의 두께나 조성비 등과 함께 타원법이 가지고 있는 높은 수준의 측정 정밀도를 유지하며 기존의 모델링 분석방법으로 결정할 수 있도록 하였다.

• 한국항공우주학회지
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• 제43권2호
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• pp.133-140
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• 2015

본 논문에서는 단일 저가형 범용 GPS 수신기와 롤 축 각속도계를 이용하여 롤 회전 비행체의 롤 자세각을 결정하는 기법을 제안한다. 비행체에 부착된 GPS 수신기의 신호 수신강도는 GPS안테나가 향하는 방향과 비행체의 종축이 이루는 평면 내에 GPS위성이 존재할 때 최대가 된다. 비행체의 종축이 속도벡터와 일치한다고 가정하면, 비행체에 대한 GPS위성의 상대위치벡터를 이용하여 GPS 안테나 신호가 최대일 때의 롤 각을 결정할 수 있다. 롤 각 결정의 정밀도를 높이기 위해 롤 축 각속도계를 이용한 칼만필터를 구성하였다. 6-자유도 시뮬레이션을 통해 제안된 방법의 성능을 검증하였다.

• 한국운동역학회지
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• 제19권4호
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• pp.663-669
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• 2009

본 연구의 목적은 런닝 턴 동작시 많은 정확한 턴을 위한 방법으로 발의 움직임을 역학적으로 분석하기 위함이다. 런닝 턴 동작에 대한 많은 역학적인 요인들 중 정확한 턴을 위해서는 감속이 발생되고 이런 감속은 진행하고자 하는 방향으로 턴을 할 수 있게 해준다. 턴이 시작되는 시점인 발의 회전각과 이로 발생되는 몸통의 각을 3차원 영상분석과 지면반력 분석을 하였다. 따라서, 여러 매개변수들 중 수직축(z축)에서 발의 총 회전각($\theta_f$)/몸통 총 회전각($\theta_d$)= 발의 효과($\varepsilon$)로 단순화 시켜 간단한 방정식을 만들어서 설명했으며, 자료 산출을 위해 평균 속력 4.5m/s에서 진행 방향 $0^{\circ}$, $30^{\circ}$, $60^{\circ}$ 턴에 대한 분석을 통해 턴의 각이 커지면 커질수록 입각기 시간, 발 변위, 좌 우힘이 증가했음을 알 수 있었다.