• Maxillofacial Plastic and Reconstructive Surgery
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• 제19권1호
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• pp.25-34
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• 1997

This study was made with lateral cephalometric radiography of 28 skeletal class III malocclusion patients that were performed to setback surgery of mandible. The 28 patients were selected by four standards as follows. 1) Set-back amount of mandible is below 10 mm 2) No extrusion and intrusion of posterior tooth or alteration of interincisial angle at period of postoperative orthodontic treatment. 3) Change of mesial segment location of mandible on lateral cephalometrics 4) No genioplasty And 28 patients were divided to three group(1,2,3 group) by degree of preoperative occlusal plane angle to Burstone's horizontal plane. The preoperative occlusal plane angle, which of 1 group was smaller than $7^{\circ}$ and 2 group was between $7^{\circ}$ to $15^{\circ}$ and 3 group was larger than $15^{\circ}$. The results were as follows : 1. As the preoperative occlusal plane angle was larger, the degree of mandibular prognathism was not severe. 2. On comparsion of preoperative and immediate postoperative cephalometric analysis, specific relationship of occlusal plane angle and set-back amount of mandible was not present. 3. As the preoperative occlusal plane angle was smaller, the alteration of postoperative occlusal plane angle was increased tendency. As the preoperative occlusal plane angle was larger, the alteration of postoperative occlusal plane angle was decreased tendency. 4. The relapsed degree of B point distance to Vertical plane was not relationship to the degree of preoperative occlusal plane angle.

• 한국운동역학회지
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• 제19권1호
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• pp.59-66
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• 2009

본 연구의 목적은 국내 엘리트 골프선수들을 대상으로 3차원 스윙 평면 분석(swing plane analysis)을 통해 스윙 평면의 편평도를 확인하여 이들 스윙이 어떤 유형의 스윙인지를 확인하는 것이 목적이었다. 또한 편평도를 이용한 스윙평면 분석 이외에 또 다른 운동학적 변인을 이용한 스윙 평면 분류가 가능한지도 확인하였다. 그 결과 편평도와 핸디캡간의 상관성은 없는 것으로 판명되었고 단일 및 다중 평면 스윙 그룹간의 편평도 비교를 실시한 결과 유의한 차이를 확인할 수가 있었다. 두 스윙 그룹을 구분하는 대표적인 특징인 백스윙 및 팔로우드로우에서의 스윙 궤도차이를 확인하기 위해 실시한 두 스윙 그룹 간 event 별 편평도 비교에서 그 유의한 차이를 확인함으로서 본 연구에서 정의한 오차범위 10cm는 두 스윙 스타일을 구분하는데 유효한 것으로 확인이 되었다. 편평도를 이용한 스윙평면 분석 이외에 운동학적 변인인 두 스윙 그룹 간 샤프트 단위벡터 비교와 샤프트 원위점 변위 비교를 event 별로 실시한 결과 통계적으로 유의한 차이는 확인이 되지 않았다. 하지만 전체적인 변인들의 이동패턴을 살펴 볼 때 각각의 스윙 그룹의 특징을 잘 보여주고 있기 때문에 스윙 스타일을 판단하는 간접적인 지표가 될 가능성을 보여주었다.

• Smart Structures and Systems
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• 제26권4호
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• pp.435-449
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• 2020

To effectively extract the vast wind resource, offshore wind turbines are designed with large rotor and slender tower, which makes them vulnerable to external vibration sources such as wind and wave loads. Substantial research efforts have been devoted to mitigate the unwanted vibrations of offshore wind turbines to ensure their serviceability and safety in the normal working condition. However, most previous studies investigated the vibration control of wind turbines in one direction only, i.e., either the out-of-plane or in-plane direction. In reality, wind turbines inevitably vibrate in both directions when they are subjected to the external excitations. The studies on both the in-plane and out-of-plane vibration control of wind turbines are, however, scarce. In the present study, the NREL 5 MW wind turbine is taken as an example, a detailed three-dimensional (3D) Finite Element (FE) model of the wind turbine is developed in ABAQUS. To simultaneously control the in-plane and out-of-plane vibrations induced by the combined wind and wave loads, another carefully designed (i.e., tuned) spring and dashpot are added to the perpendicular direction of each Tuned Mass Damper (TMD) system that is used to control the vibrations of the tower and blades in one particular direction. With this simple modification, a bi-directional TMD system is formed and the vibrations in both the out-of-plane and in-plane directions are simultaneously suppressed. To examine the control effectiveness, the responses of the wind turbine without control, with separate TMD system and the proposed bi-directional TMD system are calculated and compared. Numerical results show that the bi-directional TMD system can simultaneously control the out-of-plane and in-plane vibrations of the wind turbine without changing too much of the conventional design of the control system. The bi-directional control system therefore could be a cost-effective solution to mitigate the bi-directional vibrations of offshore wind turbines.

• Structural Engineering and Mechanics
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• 제34권2호
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• pp.143-157
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• 2010

This paper presents theoretical solutions for the three-dimensional (3D) stress field in an infinite isotropic elastic plate containing a through-the-thickness circular hole subjected to far-field in-plane loads by using Kane and Mindlin's assumption. The dangerous position, where the premature fracture or failure of the plate will take place, the expressions of the tangential stress at the surface of the hole and the out-of-plane stress constraint factor are found in a concise, explicit form. Based on the present theoretical solutions, a comprehensive analysis is performed on the deviated degree of the in-plane stresses from the related plane stress solutions, stress concentration and out-of-plane constraint, and the emphasis has been placed on the effects of the plate thickness, Poisson's ratio and the far-field in-plane loads on the stress field. The analytical solution shows that the effects of the plate thickness and Poisson's ratio on the deviation of the 3D in-plane stress components is obvious and could not be ignored, although their effects on distributions of the in-plane stress components are slight, and that the effect of the far-field in-plane loads is just on the contrary of that of the above two. When only the shear stress is loaded at far field, the stress concentration factor reach its peak value about 8.9% higher than that of the plane stress solutions, and the out-of-plane stress constraint factor can reach 1 at the surface of the hole and is the biggest among all cases considered.

• 한국결정성장학회지
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• 제24권3호
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• pp.89-93
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• 2014

V/III족 ratio의 변화에 따른 r-plane의 sapphire 위에 HVPE로 성장한 a-plane GaN 에피텍셜층의 특성변화를 연구하였다. V/III족 ratio가 증가함에 따라서, a-plane (11-20) GaN에 대한 Rocking Curve의 FWHM의 값이 감소하며, 성장된 GaN의 표면 거칠기도 감소하고, 성장성도는 증가하다가 V/III족 ratio 7까지는 증가하다가 다시 감소하는 경향을 보여준다. 즉 V/III족 ratio 10에서 a-plane (11-20) GaN에 대한 Rocking Curve의 FWHM의 가장 작은 829 arcsec값을 보이고, 표면거칠기도 가장 작은 1.58 nm 값을 보인다. 또한 광학현미경상에서 관찰되는 내부 Crack 또는 void가 가장 적게 발생하였다. 그리고 M모양의 Azimuth angle 의존도를 전 샘플에서 보이며, V/III족 ratio 10에서 FWHM 최대값과 최소값의 편차값이 439 arcscec로 가장 작은 차이를 보였다.

• 대한치과교정학회지
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• 제22권4호
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• pp.869-880
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• 1992

The purpose of this study was to evaluate the difference and relationship between the slope of articular eminence and the inclination of upper and lower incisor teeth, which are related to the functional stability of occlusion in mandibular protrusion, according to Ricketts' facial types, by the use of lateral cephalogram and SAM2 articulator in 68-adult normal occlusion without tooth missing, orthodontic treatment and occlusal equilibration. The results of this study were as follows : 1 . The angle of articular eminence slope to occlusal plane in brachyfacial type was steeper than that in dolichofacial type, but the angle of articular eminence slope to SN plane and FH plane was not different between facial types. 2. The upper incisor axis in dolichofacial type was steeper than that in brachyfacial type, but lingual surface slope of upper incisor was not different between facial types. 3. In all samples there was a positive correlation between the angle of articular eminence slope and the lingual surface slope of upper incisor to SN plane and FH plane, and in mesofacial type there was a positive correlation between the angle of articular eminence slope and the lingual surface slope of upper incisor to SN plane, FH plane and occlusal plane, and in brachyfacial type there was a positive correlation between the angle of articular eminence slope and the lingual surface slope of upper incisor to occlusal plane. 4. In all samples there was a positive correlation between the angle of articular eminence slope and the angle of Dc-Gn to SN plane, and in mesofacial type there was a positive correlation between the angle of articular eminence slope and the angle of Dc-Gn to occlusal plane, and in brachyfacial type there was a positive correlation between the angle of articular eminence slope and the angle of Dc-Gn to SN plane and FH plane. 5. In all samples there was a positive correlation between the angle of Dc-Gn and the lingual surface slope of upper incisor to SN plane and FH plane, and in mesofacial type there was a positive correlation between the angle of Dc-Gn and the lingual surface slope of upper incisor to SN plane. 6. In all samples and facial types there was a negative correlation between MP to 1 axis and condylar incisal angle.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2010년도 제39회 하계학술대회 초록집
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• pp.151-152
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• 2010

극성 [0001] 방향으로 성장 된 질화물 기반의 LEDs (light emitting diodes) 는 분극현상에 의해 발생하는 강한 내부 전기장의 영향을 받게 된다. 이러한 내부 전기장은 양자우물 내의 전자와 정공의 공간적 분리를 야기하고 quantum confined Stark effect (QCSE) 에 의한 발광 파장의 적색 편이가 발생하며 양자효율의 저하를 가져오게 된다. 이러한 문제를 해결하기 위해 양자 우물구조를 GaN 의 m-plane (100) 이나 a-plane (110) 등 비극성면 위에 성장하려는 시도를 하고 있다. 그러나 비극성면의 비등방성 (anisotropy) 으로 인하여 결정성이 높은 비극성 GaN을 성장하는 데에는 많은 어려움이 있다. 비극성 a-plane GaN 의 결정성과 표면 거칠기의 향상을 위해 경사각을 가지는 r-plane 사파이어를 기판으로 이용하는 연구들이 많이 진행되어 있다 [1-4]. 그러나 r-plane 사파이어 기판의 경사각과 표면의 pit 형성에 관한 상관관계의 체계적인 연구는 상대적으로 많이 진행되지 않았다. 본 연구에서는 경사각을 가진 r-plane 사파이어 기판에 유기금속화학증착법을 (MOCVD) 이용하여 a-plane GaN 을 성장하였으며, 성장 시 기판의 경사각이 a-plane GaN의 성장 거동 및 표면형상에 미치는 영향을 분석하였다. 본 실험에서는r-plane에서 m-axis방향으로 0도에서 -0.65도의 경사각을 가지는 r-plane 사파이어 기판을 이용하였다. a-plane GaN 성장에는 고온 GaN 핵 형성층을 (nucleation layer) 이용하는 2단계 성장 법이 사용되었다 [5]. -0.37도 보다 크기가 큰 경사각을 가진 r-plane 사파이어에 성장된 a-plane GaN의 표면에는 수 ${\mu}m$ 크기의 삼각형 형태의 pit이 형성되었다. 사파이어의 경사각이 -0.37도에서 -0.65도로 증가하였을 경우에, GaN의 m방향 X-ray 록킹커브 반치폭은1763 arcsec에서 1515 arcsec로 감소하였으나 표면에 삼각형 pit의 밀도는 103 cm-2 이하에서 $2{\times}106$ cm-2으로 증가하였다. 이러한 r -plane 사파이어 기판의 경사각의 차이로 표면에 pit이 발생과 결정성변화의 원인을 확인하기 위해서, 여러가지 다른 경사각을 가진 사파이어 기판의 표면에 성장된 핵 형성층의 표면 양상을 확인하였다. 발표에서는 경사각의 차이에 따른 기판 표면에서의 원자 step 구조와 GaN 의 핵 형성 간의 상관관계에 대하여 구체적으로 논의할 것이다.

• The Journal of Advanced Prosthodontics
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• 제5권1호
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• pp.9-15
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• 2013

PURPOSE. The purpose of this study was to determine accurately the part of the tragus to be used to form the Ala-Tragal line or Camper's line in orthognathic profile patients. MATERIALS AND METHODS. 150 dentate subjects with age of 18-40 years with orthognathic profile were sampled. Life-size lateral digital photographs of the face with fox plane were taken in natural head position. Different angles between Eye-Ear plane and occlusal plane ($OT_1$-OP), Eye-Ear plane and ala-superior border of tragus ($OT_1-AT_1$), Eye-Ear plane and ala-middle border of tragus ($OT_1-AT_2$) and Eye-Ear plane and ala-inferior border of tragus ($OT_1-AT_3$) were calculated using computer software package, AutoCAD 2004. From the three angles formed by the Eye-ear plane ($OT_1$ or FH plane) and the ala-tragal lines, the one closest to the angle formed between Eye-Ear plane ($OT_1$) and occlusal plane (OP) was used to determine the occlusal plane of orientation. The obtained results were subjected to ANOVA F test, Tukey's Honestly significant difference test, followed by Karl Pearson coefficient of correlation test. P values of less than 0.05 were taken as statistically significant. RESULTS. The mean of base line angle i.e. $OT_1$-OP angle ($11.96{\pm}4.36$) was found to be close to $OT_1-AT_2$ angle ($13.67{\pm}1.93$) and $OT_1-AT_3$ angle ($10.31{\pm}2.03$), but $OT_1$-OP angle was found to be more closer to $OT_1-AT_3$ angle. Comparison of mean angles showed that $OT_1$-OP angle in both males (11.68) and females (12.51) is close to $OT_1-AT_3$ angle (males- 11.01, females- 11.95). CONCLUSION. The line joining from ala to the lower border of the tragus was parallel to the occlusal plane in 53.3% of the subjects. There was no influence of the sex on the level of occlusal plane.

• 치과방사선
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• 제16권1호
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• pp.59-68
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• 1986

The purpose of this investigation was to locate the central plane of the image layer on the panoramic machine relative to a specific point on the machine. In the study of the central plane of the image layer of panoramic radiograph, using the Morrita Company PANEX-EC a series of 33 exposures were taken with the 4-5 experimental pins placed in the holes of the plastic model plate, then evaluated by human eye. The author analyzed the central plane of the image layer by Mitutoyo-A-221 and calculated horizontal and vertical magnification ratio in the central plane of the image layer determined experimentally. The results were as follows: 1. The location of the central plane of the image layer determined experimentally was to lateral, compared with manufactural central plane. 2. Horizontal magnification ratio in the central plane of the image layer determined experimentally was 9.25%. 3. Vertical magnification ratio in the central plane of the image layer determined experimentally was 9.17%.

• 한국산학기술학회논문지
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• 제15권1호
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• pp.436-440
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• 2014

본 논문에서는 PCB Plane 레이어가 SMPS에 미치는 영향을 확인하기 위하여 일반적인 단면 PCB와 Plane을 갖는 양면 PCB를 이용한 SMPS의 출력특성을 각각 분석하였다. 그 이후 동일한 레이아웃을 갖는 PCB의 반대 면에 Ground Plane을 설치한 양면PCB를 이용하여 SMPS 기판을 작성하여 단면 PCB SMPS에 적용해서 분석한 모든 부품을 이동 실장한 후 두 SMPS의 출력특성을 전압, 전류, 고주파잡음 측면에서 비교 분석하였다. 그 결과 단면PCB의 SMPS는 100MHz대역의 고주파 잡음이 150mV인 반면, Ground Plane을 설치한 SMPS에서는 50mV로 1/3 저감되는 현상을 확인하였다. 그리고 고주파 잡음 성분 또한 감소됨을 확인하였다.