• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2003년도 춘계학술대회 논문집
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• pp.49-55
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• 2003

When a body with slant angle after its shoulder is moving at high speed, the turbulent motion around the afterbody is generally associated with the flaw separation and determines the normal component of the drag. By changing the slant angle of afterbody, there exists a critical angle at which the drag coefficients change drastically. Understanding and control of the turbulent separated flows are of significant importance for the design of optimal configuration of the moving bodies. In the present paper, a new Large Eddy Simulation technique has been developed to investigate turbulent vortical motions around the afterbodies with slant angle. By basis of understanding the structure of turbulent flaw around the body, the new configuration of afterbodies are designed to reduce the drag of body and the nonlinear effects due to the interaction between the body configuration and the turbulent separated flows are investigated by use of the developed LES technique.

• 척추신경추나의학회지
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• 제14권1호
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• pp.39-47
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• 2019

Objectives : The purpose of this study was to evaluate the scientific literature demonstrating the effectiveness of Chuna manual therapy (CMT) in the treatment of spinal scoliosis. Methods : A literature search was conducted using eight electronic databases to identify all randomized controlled clinical trials (RCTs) that investigated CMT as a treatment for spinal scoliosis. The Cochrane risk of bias tool was used to assess the methodological quality of each RCT. Results : Five RCTs met our inclusion criteria and were included in the analysis. These studies demonstrated positive results of CMT with respect to the reduction of Cobb's angle, vertebral rotation angle score, bending test score, and efficacy rate compared with brace treatment. Positive results were also assured, in terms of the reduction of Cobb's angle, pulmonary function, and efficacy rate when comparing CMT combined with other therapy with brace treatment, gymnastic training, or traction therapy. Conclusions : This review has identified encouraging and limited evidence of CMT for the treatment of spinal scoliosis. However, to obtain stronger evidence, without the disadvantages of study design and quality, we recommend that treatment effectiveness of CMT for spinal scoliosis is investigated further using a well-designed RCT.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 추계학술대회 논문집
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• pp.15-19
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• 1996

The cusp height in ball end milling, flat end milling and filleted end milling according to various surface inclination angle was calculated. The calculation result shows that, for each kind of tools, there exists certain range of inclination angle in which cusp height characteristics favorable. From machining time calculation, filleted end mill found to be superior to flat end mill in rough machining of sculptured surface.

• 멤브레인
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• 제22권5호
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• pp.332-341
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• 2012

실리카 콜로이드 용액의 정유량 한외여과에서 중력 방향에 대한 막모듈의 위치(경사각) 변화에 따라 발생되는 자연대류 불안정 흐름의 막오염 저감효과를 차압의 변화 정도를 측정하여 규명하였다. 막표면에 케이크 층을 형성함으로서 막오염을 발생시키는 나노 사이즈의 실리카 입자(평균 크기 = 7, 12, 22, 50 nm 및 78 nm)가 함유된 5가지 종류의 콜로이드 용액을 사용하여 중력 방향에 대한 막모듈의 위치(경사각 = $0^{\circ}{\sim}180^{\circ}$)에 따른 차압의 변화를 교반이 없는 dead-end 정유량 한외여과 실험을 통해 측정하였다. 상대적으로 크기가 작은 실리카 입자(7, 12 nm 및 22 nm)가 함유된 콜로이드 용액의 정유량 한외여과에서 막모듈 경사각을 $30^{\circ}$ 이상으로 유지하면 막모듈에 자연대류 불안정 흐름이 발생되어 막오염 형성을 크게 억제시켜 차압의 증가가 거의 나타나지 않았다. 이 자연대류 불안정 흐름의 발생은 막표면에 형성된 실리카 케이크층의 벌크용액으로의 역이동(back transport)을 유발시킴으로서 차압의 증가를 억제시키는 막성능 개선 효과를 나타내었다. 그러나 상대적으로 크기가 큰 실리카 입자(50 및 78 nm)가 함유된 콜로이드 용액의 정유량 한외여과에서는 자연대류 불안정 흐름 발생의 효과가 거의 없었다. 임계 플럭스 측정 결과 실리카 입자의 크기가 작을수록 그리고 막모듈 경사각이 클수록 막모듈에의 자연대류 불안정 흐름의 발생 강도가 커져 막오염 형성이 억제되었으며, 이로 인해 임계 플럭스가 증가하였다.

• Archives of Hand and Microsurgery
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• 제23권4호
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• pp.239-247
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• 2018

목적: 골성 추지의 치료로 신전 제한 K 강선 고정 또는 추가 골편간 고정 후 발생한 정복 소실과 원위지관절 신전지연을 포함한 임상적 결과를 분석하였다. 방법: 평균 추시 기간 28개월(12-54개월)의 46명을 대상으로 하였고, 27명은 신전 제한 K 강선 고정(A군)으로, 19명은 추가 골편 간 고정(B군)으로 치료하였다. 관절면 침범 정도, 전방아탈구, 추지 골편각, 정복 소실, 관절운동 범위, Crawford 기준을 이용한 기능적 결과를 평가하였다. 결과: 정복 소실은 8예(17%)에서 발생하였다. 신전 제한 정도, 연령, 술 전 전방아탈구 및 추지 골편각은 정복 소실여부에 따른 차이가 유의하였으나 성별, 우세 수, 관절면 침범 정도 및 추가 골편 간 고정은 정복 소실 여부에 따른 차이가 유의하지 않았다. 전위 양상은 골편 틈 또는 계단 변형은 신전 제한과 상관관계가 있었다. Crawford 기준상 우수 31, 양호 10, 보통 3, 그리고 불량이 2예였다. 결론: 고령, 적은 추지 골편각, 술 전 전방아탈구가 있는 경우는 정복 소실에 대한 주의가 필요하다.

• 한국안전학회지
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• 제22권5호
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• pp.41-49
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• 2007

In general, the curved structures have the engineering efficiency as well as a fine view compared with straight member. Also, composite materials are composed of two or more different materials to produce desirable properties for structural strength as compared to single ones. Shell structures with composite materials have many advantages in strength and weight reduction. Therefore, composite laminated conical shells are analyzed in this study. To solve differential equations of conical shells, this paper used finite difference method. Various parametric study according to the change of radius ratio, vertex angle and subtended angle are examined. The change of radius ratio, vertex angle and subtended angle mean the change from conical shells to cylindrical shells, conical shells to circular plates and open shells closed shells, respectively.

• 대한기계학회논문집A
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• 제30권10호
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• pp.1269-1275
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• 2006

The purpose of this study is to investigate the effect of bend angle on the collapse behavior of locally wall thinned pipe bends. For this purpose, the present study performed three-dimensional finite element analysis on the 30-, 60-, and 90-degree pipe bends with local wall thinning at the center of intrados, extrados, and crown, and evaluated the collapse moment for different thinning dimensions under closing- and opening-mode bending with a constant internal pressure. The results showed that, for intrados and extrados wall thinning, the reduction in the collapse moment due to local wall thinning became significant with decreasing bend angle of pipe bends. This effect of bend angle was enhanced with increasing thinning dimensions, and it was clearer fur opening-mode bending than for closing-mode bending. For crown wall thinning, however, the effect of bend angle was unclear and was less sensitive to the change of wall thinning shapes.

• 한국기계가공학회지
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• 제10권2호
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• pp.110-116
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• 2011

The current study investigated the friction property of angle and width effect for micro-scale grooved crosshatch pattern on SKD11 steel surface against bearing steel using pin-on-disk type. The samples fabricated by photolithography process and then these are carry out the electrochemical etching process. We discuss the friction property due to the influence of a hatched-angle and a width of groove on contact surface. We could be explained the lubrication mechanism for a Stribeck curve. So It was found that the friction coefficient depend on an angle of the crosshatch on contact surface. It was thus verified that micro-scale crosshatch grooved pattern could affect the friction reduction. Also, it is play an important a width of groove to be improved the friction property. I was found that friction property has a relationship between a width and an angle for micro-grooved pattern.

• 한국지반공학회논문집
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• 제31권2호
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• pp.27-37
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• 2015

마이크로파일은 직경 300mm 이하의 소규모 말뚝기초형식으로, 기초구조물의 보강을 위해 널리 적용되고 있다. 본 연구에서는 일련의 인발재하시험을 통하여 그룹 마이크로파일의 설치조건에 대한 영향을 조사하였다. 본 연구를 위하여, 다양한 설치간격과 설치각도로 설치된 그룹 마이크로파일을 이용한 인발재하시험을 수행하였으며, 실험결과를 통해 인발지지력 증가특성과 인발변위 감소특성을 조사하였다. 인발저항력은 주로 마이크로파일의 설치각도에 영향을 받는 것으로 나타났으며, 인발저항력의 증가는 설치각도 15도, 30도, 45도에서 각각 33%, 59%, 5%가 증가되는 것으로 나타났다. 설치간격에 따른 인발변위의 감소량은 더 좁은 설치간격조건에서 크게 나타났으며, 동일한 설치간격조건에서의 설치각도에 따른 인발변위 저감율은 설치각도 15도, 30도, 45도에서 각각 50%, 53%, -45%가 되는 것으로 나타났다.

• 대한족부족관절학회지
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• 제11권1호
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• pp.86-90
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• 2007

Purpose: We evaluated the results of operative treatment with F or H plates and screws using extensile lateral approach in intraarticular calcaneal fractures. Materials and Methods: From August 2003 to July 2006, twenty intraarticular calcaneal fractures which were operated with open reduction and internal fixation with F or H plates and screws were evaluated retrospectively. According to the Essex-Lopresti classification, 3 cases were tongue type and 16 were joint depression type. With the Sanders classification, 2 cases were IIA type, 7 were IIB, 5 were IIIAB, 2 were IIIAC and 3 were IV. We have analysed the $B{\ddot{o}}hler$ angle, Gissane angle, and calcaneal width in radiologic evaluation, and evaluated clinical result according to the Creighton-Nebraska Health Foundation Score. Results: Radiologic changes showed as follows: $B{\ddot{o}}hler$ angle improved from $5.8^{\circ}$ to $25.9^{\circ}$, Gissane angle from $119.0^{\circ}$ to $113.3^{\circ}$, and calcaneal width from 50.4 mm to 37.8 mm. In the clinical results, excellent cases were noted in 8 cases, good in 8 cases, fair in 2 cases, poor in 1 case. Conclusion: Operative treatment with F or H plates and screws using extensile lateral approach in intraarticular calcaneal fractures was thought to be a useful operative method allowing anatomical reduction.