• Clinics in Shoulder and Elbow
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• v.11 no.2
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• pp.77-81
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• 2008

The goal of rotator cuff repairs is to achieve high initial fixation strength, minimize gap formation, maintain mechanical stability under cyclic loading and optimize the biology of the tendon-bone interface until the cuff heals biologically to the bone. Single row repairs are least successful in restoring the footprint of the rotator cuff and are most susceptible to gap formation. Double row repairs have an improved load to failure and minimal gap formation. Transosseous equivalent repairs (suture bridge technique) have the highest ultimate load and resistance to shear and rotational forces and the lowest gap formation. Even though the superior advantages of double row and transosseous equivalent repairs, those techniques take longer surgical time and are more expensive than single row repairs. Therefore single row repairs can be useful in bursal side partial thickness or small size full thickess rotator cuff tear.

• Solar Energy
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• v.13 no.2_3
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• pp.120-132
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• 1993

The purpose of this research is to study the characteristics of heat transfer in composite rotary heat pipe as modeled turbine rotating by a finite element analysis and experiment. Nu number, Re number, Pr number and dimensionless condensate layer thickness by thermal input and revolutions per minute were given as analysis factors. The comparison between calculated and experimental data showed similar tendency. Therefore the analysis method may be useful to predict the performance of composite heat pipe. The resistance on heat pipe showed the best effect of heat transfer by film condensation, by decreasing film condensation, the heat transfer rate from condenser was increased rapidly. The dimensionless condensate layer thickness according to Re number at given Pr number showed constant values, the dimensionless condensate layer thickness is proportionate to the square root of inverse of revolution number per minute. In this study Nu=A$({\delta}({\omega}/v)^{-1/2}Re^B)$ is used to the convection heat transfer coefficient and A=0.963, B=0.5025 were obtained as analysis predicts.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.9
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• pp.753-760
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• 2007

In a 3-D flapping motion, the spanwise flow is generated while the wing is moved on the stroke plane. And at the end of each stroke, the rotational circulation is generated due to a wing rotation. In this study, to evaluate the effect of spanwise flow and wing rotation on the aerodynamic characteristics in 3-D flap 753ping motion, a 3-D flapping motion was compared with a 2-D translating motion. In each flapping motion, the aerodynamic forces were measured with respect to the angles of attack and Reynolds number. The aerodynamic forces generated by 2-D translating motion were higher than those generated by 3-D flapping motion. While the lift of 3-D flapping motion was increased until the angle of attack $60^{\circ}$ at mid-stroke, the lift generated by 2-D translating motion was decreased above the angle of attack 40° at mid stroke. Also, at the end of each stroke, the aerodynamic forces were increased rapidly due to wing rotation.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.173-177
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• 2011

만곡도가 높은 하천의 경우 수위가 상승하게 될 때 만곡부에서의 흐름 회전 방향이 나선형 흐름으로 바뀌어 하류방향으로 주 흐름에 중첩하여 발생하는 이차류로 인해 하도가 불안정해지고 내 외측의 수위차가 발생하는 편수위가 발생하면서 하도 바깥쪽으로 수위가 상승하는 현상이 나타나게 된다. 이와 같은 만곡부의 외측부에서 발생하는 수위상승은 제방의 월류 피해와 이차류로 인한 침식 피해를 유발하게 된다. 하천에서의 만곡은 보편적인 현상이며, 흐름의 물리적인 현상으로 인해 발생하는 자연현상이다. 본 연구에서는 만곡수로의 내 외측부에서 발생하는 유속과 편수위 현상과 같은 수리학적 특성을 규명하기 위해 $90^{\circ}$ 하도와 $180^{\circ}$ Sharp 하도와 같은 만곡 실험하도를 대상으로 SMS 모형, RAMS 모형 그리고 CCHE2D 모형과 같은 3개의 2차원 모형을 적용하고 그 결과를 실측자료와 비교함으로써 만곡부에서의 2차원 수리 특성을 살펴보았다. 또한 과거에 개발된 편수위 산정공식들의 적용성을 살펴보기 위해 주요 지점의 실측자료와 2차원 모형의 모의자료를 이용하여 만곡부의 편수위를 산정하여 비교 검토하였다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2016.01a
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• pp.27-30
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• 2016

본 논문은 일체형 플랫폼 디바이스인 ATMEGA-128을 이용하여 추적하는 이동로봇에 대해 서술한다. 최근 하드웨어의 개발로 일체형 플랫폼 디바이스들이 많이 개발되고 있다. 또한 디바이스와 센서 등을 접목한 여러 가지 제품들이 만들어 지고 있다. 본 논문에서는 일체형 플랫폼 디바이스중 하나인 ATMEGA 및 초음파 장비를 활용한 이동로봇의 설계 및 구현에 대해 서술한다. 초음파 장비의 발신부는 마이크로폰을 이용하여 초음파를 발생시키고 이동로봇에 부착된 수신부에서는 마이크로폰으로부터 초음파 신호를 수신 대기 한다. 이후, 수신 감도의 정확성 향상을 위해 초음파 신호를 증폭시켜 값을 판단 한다. 해당 신호를 통해 이동로봇은 초음파 신호 발신부와 수신부 사이의 거리 값을 알아낸다. 이후 가장 가까운 거리 값을 나타내는 방향을 로봇의 전면부가 되게 회전하고 직진하여 최종적으로 로봇은 발신부 방향으로 이동하게 된다.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.573-576
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• 2008

절토사면 및 천심도 터널의 경우 불연속면을 따른 블록의 미끄러짐 및 회전 등이 안정성에 큰 영향을 미친다. 국도나 지방도 등을 확장 공사함에 따라 산악이 많은 우리나라 지형의 특성상 절토사면이 많이 발생하게 되고, 경우에 따라서는 이러한 절토사면에 터널이 위치하게 된다. 이런 상황의 터널갱구부 및 인접한 절토사면부에서 붕괴 및 균열이 빈번하게 발생되고 있다. 본 연구에서는 대절토사면과 인접한 터널갱구부에 대하여 편토압이 균열의 주원인인지를 결정하기 위하여 변위 및 응력 패턴을 분석한 사례연구를 제시하였다. 조사대상지역은 울진군에 위치한 터널굴진 현장이고, 붕괴는 터널갱구부와 인접한 절토사면부에서 발생하였으며 터널갱구부 상단의 숏크리트 타설지역에서 다수의 균열이 관찰되었다. 언급한 터널갱구부의 변위 및 응력패턴을 모사하기 위하여 유한차분법에 근거한 플랙을 사용하였으며, 세밀한 수치해석을 위해 편재절리모델을 도입하였다. 마지막으로, 터널갱구부의 균열에 영향을 미친 주원인에 대한 고찰을 다루었다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.6
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• pp.2458-2464
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• 2012

Recently, component materials for display are being developed into higher value-added industries which can strengthen national industrial competitiveness. However, a system for production of component materials for display is nearly depending on import, and its development level is inadequate. For this reason, localization of the embossing treatment system for production of the spacer tape and system improvement for increasing of productivity are needed. Therefore, in this paper, we propose rotary type embossing process system for spacer tape production for localization of system and increasing productivity. The system consists of unwinding, forming, cleaning, winding and testing parts. The mold of forming part is designed to rotary type. And we designed each part and made a prototype to test its performance. We measured embossing shapes, diameter and distance between each embossing and opposite embossing using three coordinate measuring machine. Also, we measured impurity level and the number of impurity particles of sample through the testing and cleaning part. Additionally, the productivity of spacer tape produced by the prototype is measured.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.31 no.1
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• pp.9-16
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• 2019

Flow velocity changes in the shroud system for tidal current power generation due to experimental flow velocities and blade geometry changes were analyzed by hydraulic experiment and numerical simulation. Through the hydraulic experiment, flow velocities at inlet of shroud system and RPM according to blade geometry were measured, and numerical simulation was used to analyze flow velocity changes in shroud. When the experimental flow velocity was increased by about 28% and the shape of the airfoil was applied, the measured flow velocity at the shroud inlet tended to increase by up to about 56%. On the other hand, when airfoil-shaped blades were installed, the flow velocity at the inlet tended to increase by up to 14% compared to conventional blades, and RPM was also the highest at the same conditions. The hydraulic experiment and numerical simulation results showed an error of about 13%, and the trends of the flow velocity changes in each result are similar. Numerical simulation of the flow velocity changes in the shroud showed that the flow velocity tended to increase 1.7 times at the front of the blade compared to the inlet. The results of the flow velocity change analysis in the shroud system obtained from this study will provide the basic data necessary for the development of efficient shroud system for tidal current power generation.

• Journal of Korean Society of Steel Construction
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• v.26 no.5
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• pp.431-439
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• 2014

Concrete filled tubular columns are widely used because the mutual reaction between the concrete and the tube improves strength and ductility of the columns. In an attempt to secure efficient use of members, built-up square columns featuring large width-thickness ratio and the use of thin steel plates are suggested in this study. In order to evaluate the structural characteristics and seismic performance of the column-to-beam connections of the new shape columns, cyclic load test of T-shaped column-to-beam connections was conducted with variables of diaphragms and concrete-filling. Moment-rotational angle relationship, dissipated energy and failure behavior were compared to evaluate stress transfer mechanism of the new shape built-up square column-to-beam connections associated with the variables.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.29 no.5
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• pp.323-329
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• 2003

The present study was carried out to evaluate the postoperative results of Millard rotation-advancement repair (MR) and lip adhesion followed by Millard rotation-advancement repair (LAMR) in unilateral complete cleft lip. Twenty patients with unilateral complete cleft lip underwent MR or LAMR at the Department of Oral and Maxillofacial Surgery of Chonnam University Hospital over a period of 6 years (January 1994 to December 1999) were analyzed. The surgical results following the operation were assessed on the basis of scoring, vertical lip length, and scar hypertrophy. The mean score was better in LAMR group ($74.74{\pm}1.09$, n=13) than in MR group ($66.50{\pm}1.14$, n=7) for both lip and nose segments. Scar hypertrophy developed in MR group with 28.6% and in LAMR group with 23.1%. No significant difference was noted in the ratio of lip length between LAMR and MR groups ($0.84{\pm}0.08\;and\;0.73{\pm}0.10$). These results suggest that LAMR is better than MR in repairing the unilateral complete cleft lip.