• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2001년도 춘계 학술대회논문집
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• pp.72-77
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• 2001

The computational efficiency of an shape optimization procedure is highly dependent upon the proper selection of shape representation methods and design variables. In this study, shape functions, Bezier and NURBS(non-uniform rational B-splines) curves are selected as configuration generation methods and their efficiencies on the nose shape design of high-speed air vehicles, are compared. The effects of the number of control points, weighting factors and the optimization methods when utilizing the NURBS curves, are investigated. By implementing Bezier and NURBS curves, shapes having lower drag than the optimization case utilizing the shape functions, were obtained, hence it was demonstrated that these curves have better capability in representing the configuration. Efforts will be given to improve the convergence behavior when utilizing the NURBS, hence to reduce the number of Navier-Stokes analysis calculations.

• 한국정보과학회논문지:소프트웨어및응용
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• 제30권9호
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• pp.885-893
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• 2003

본 논문은 3차원 얼굴영상으로부터 얼굴의 구성 요소 중의 하나인 코의 종단면과 횡단면을 이용한 특징값과 얼굴의 다를 구성 요소들로부터 구해진 특징값을 이용하여 얼굴을 인식하는 알고리듬을 제안한다. 객체와 배경을 분리하여 얼굴을 추출 및 얼굴의 최고점인 코끝을 찾은 후, 3차원 영상으로부터 얼굴의 주요 특징영역인 코 정보와 얼굴의 종단면 및 횡단면의 정보를 이용하여 회전 보상 전, 후의 특징값을 구한다. 코의 최고점, 코와 이마 사이의 미간점, 코의 밑점, 그리고 코의 앙쪽 끝점을 탐색하여 코의 종단면과 횡단면을 기준으로 한 면적, 깊이, 각도, 체적, 그리고 눈과 입의 간격을 특징값으로 사용하였다. 제안된 방법을 이용한 유사도 비교는 입력과 데이타 베이스에 대하여 각각 두 개의 깊이 데이타에 대해 유클리드 거리를 사용하였으며, 실험결과 임계 순위 값 5위 이내의 인식률이 95.5%로 나타났다.

• 한국항공우주학회지
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• 제49권11호
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• pp.901-907
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• 2021

본 연구에서는 다양한 유도탄 노즈 형상과 유동조건에 대한 공력계수를 예측할 수 있는 인공신경망 기반의 공력 산출 기법을 제시한다. Missile DATCOM를 통해 유도탄 노즈 형상, 유동조건, 유도탄 공력계수로 구성된 학습 데이터셋을 구축하였다. 인공신경망의 예측 성능을 향상시키기 위해 데이터 전처리 과정으로 데이터 정규화를 진행하였고, 과대적합을 방지하기 위해 신경망 학습 과정 중 드롭아웃 기법을 사용하였다. 신경망을 통해 학습하지 않은 유도탄 노즈 형상과 유동조건에 대한 공력계수를 예측하였고 이를 Missile DATCOM 해석 결과와 비교하여 신경망의 성능을 검증하였다. 그 결과 본 연구에서 구축한 신경망은 학습하지 않은 유도탄 노즈 형상과 유동조건에 대한 유도탄 공력계수를 정확하게 산출할 수 있음을 확인하였다.

• 동의생리병리학회지
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• 제23권1호
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• pp.34-40
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• 2009

After a research on appearance diagnosis and fish, bird, horse, and turtle types, this study concluded as following. Appearance diagnosis is a technique that exams five jang organs by color and shape of eye, nose, mouth, and ear. Four HyungSang types-including fish, bird, horse and turtle types-are evaluated upon the external shape that are created while type of seed changes. Appearance diagnosis focuses on five jang organs. Four HyungSang types focus on external shape, but are eventually related to five jang organs. Thus, two different techniques possess a point in common; five jang organs. The assignment of nose, eye, ear and mouth to the Five elements varies between two techniques. On the viewpoint of formation, appearance diagnosis assigns them to metal-water-wood-fire-earth and movement, and four HyungSang types do to wood-fire-earth-metal-water and constitution. On the viewpoint of body/use and static/dynamic, appearance diagnosis assigns them to metal-water-wood-fire-earth and constitution, and four HyungSang types do to wood-fire-earth-metal-water and movement. If nose, eye, ear, and mouth are assigned by on four HyungSang types, which are based on external shape, the assignment can be utilized in diagnosis. If, however, they are assigned by appearance diagnosis, it can be focus on treatment. Five jang organs and six fu organs are affected by internal conditions because they are located inside of human body, while four HyungSang types are affected by external conditions because it deals with external shape. If a disease occurs in the developed part of the body, it would be difficult to be cured because four HyungSang types depend on external shapes.

• 한국전산구조공학회논문집
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• 제19권2호
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• pp.139-150
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• 2006

ILM(incremental launching method) 교량공법은 품질확보에 효과적인 프리스트레스트 콘크리트 교량공법으로 인정받고 있다. 이 공법에 의해 시공되는 교량의 상부단면은 시공 중에 지간의 중앙부와 지점부에 일시적이나마 모두 위치하게 된다. 따라서 단면들은 자중에 의해 발생되는 최대 정 모멘트와 최대 부 모멘트, 그리고 최대 전단력을 모두 경험하게 되는 구조적 특성을 가지고 있다. 한편, 압출하는 동안 발생하는 높은 일시적 응력을 최소화하기 위해 일반적으로 압출추진코가 이용되고 있다. 그리고 상부단면에 발생하는 이 일시적인 응력의 크기는 압출추진코의 특성에 따라 달라진다. 본 연구에서는 압출 중 상부단면에 발생하는 단면력의 크기를 쉽고, 빠르게 검토할 수 있는 해석식을 유도하였다. 개발된 해석식에서 고려할 수 있는 매개변수로는 압출추진코와 상부단면과의 지간 길이비와 중량비 그리고 강성비를 택하였다 특히, 개발된 해석식에서는 변단면인 압출추진코의 단면형상과 다이아플램을 고려할 수 있다. 또한, 설계변수들에 대한 민감도 해석을 통하여 압출추진코와 상부단면의 상호작용에 미치는 매개변수들의 영향을 분석하였다.

• 사상체질의학회지
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• 제10권2호
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• pp.221-270
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• 1998

Objective This research is a study about constitutional diagnosis through the external appearances as a basic principle, and it is for finding shape differences of the ear, eye, nose, mouth according to the Sasang constitution Method We have collected 209 cases of patients of the Sasang Constitutional Department, including employees of the Kyung-Hee Medical Center and took pictures of the frontal view, lateral view, oblique view of face and measured heights, deapth, breadths of ear, eye, nose, mouth with 'The Measurement of R. Martin'. We analyzed shape differences of the face according to the Sasang constitution with certain results Results We got the morphologic characteristics of ear, eye, nose and mouth according to the Sasang constitution as Table 3. -Table 10. Conclusion : 1. The morphologic characteristics of Ear according to the Sasang constitution (1) Morphologic ear length, Physiognomic ear length, Ear lobule length is longer in Taeumin than Soeumin. (2) Physiognomic ear breadth is wider in Taeumin than Soeumin. (3) Physiognomic ear length, lobule length ratio is higher in Taeumin than Soyangin. 2. The morphologic characteristics of Eye according to the Sasang constitution. (1) Inner Palpebral fissure width, 5th Palpebral fissure length, Bizygomatic breadth-Outercanthal distance is the longest in Taeumin (2) Palpebral fissure inclination is widest in Soeumin. (3) Palpebral fissure length is longer in Taeumin than Soeumin. (4) Pupillary diameter ratio is the lowest in Taeumin (5) Palpebral fissure length, width ratio is higher in Soeumin than Taeumin. (6)zygomatic breadth, Bizygomatic breadth-Outercanthal distance ratio is the higher in Taeumin than Soeumin. 3. The morphologic characteristics of Nose according to the Sasang constitution. (1) Nasion depth is deepest in Soyangin. (2) Nasion to pupillary depth is deeper Soyangin than Taeumin. (3) Nasal tip depth, Nostril to Nasalalar depth is deeper Soyangin than Taeumin. (4) Subnasale to Nasalalar depth is the shallowest in Taeumin (5) Nasalalar height is lowest in Soeumin. (6) Nasalalar to Nostril distance is deeper Taeumin than Soeumin. (7) Nasal tip depth, Nasal depth ratio is the highest in Taeumin (8) Nasal depth Nasalalar heightratio is lowest in Soeumin. (9) Midfaceheight, Nasal tip depth ratio is higher Soyangin than Taeumin. 4. The morphologic characteristics of mouth according to the Sasang constitution. (1) Lower mid lip height, Lower philtrum height, Lower quarter lip height, Total middle lip height, Total philtrum height, Total quarter lip height is the shottest in Soyangin. (2) Upper mid lip height, Upper philtrum height is longer in Taeumin than Soyangin (3) Lip inclination is higher in Soeumin than Soyangin. (4) Intercheilion breadth, total height ratio is lowest in Soyangin. (5) Total lip height, Upper philtrum height ratio is higher in Soyangin than Soeumin. (6) Lower lip height Lower quarter lip height ratio is higher in Soyangin than Taeumin. (8) Total lip area is wider in Taeumin than Soyangin.

• 대한두개안면성형외과학회지
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• 제22권2호
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• pp.85-92
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• 2021

Background: Patients with secondary deformities associated with unilateral cleft lip and nose might also suffer from nostril stenosis due to a lack of tissue volume in the nostril on the cleft side. Here, we used full-thickness skin grafts (FTSGs) to reduce nostril stenosis and various methods for skin volume augmentation. We compared the changes in the symmetry of both nostrils before and after surgery. Methods: From February 2016 to January 2020, 34 patients underwent secondary cheiloplasty and open rhinoplasty for secondary deformities of the unilateral cleft lip and nose with nostril stenosis. FTSG was used on the nostril floor, nasal columella, and alar inner lining. The measured nasal profile included the nostril surface, nostril circumference, width of the nostril floor, and distance from the alar-facial groove to the nasal tip. The "overlap area," which was defined as the largest overlapping area when the image of the cleft nostril was flipped to the left and right and overlaid on the image of the normal side nostril, was also calculated. The degree of symmetry was evaluated by dividing the value of the cleft side by that of the normal side of each measured profile and expressed as "ratios." Results: The results of all profile ratios, except for the nostril floor width, became significantly close to 1, which represents full symmetry. The overlap area ratio improved from 62.7% to 77.3%, meaning that the length and width of the nostril as well as the overall shape became similar (p< 0.05). Conclusion: When performing cleft rhinoplasty with nostril stenosis, FTSG is useful to achieve symmetry in the nostril size and shape. Skin grafting is simpler to perform than the other types of local flap, and the results are generally satisfactory.

• Journal of Mechanical Science and Technology
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• 제14권8호
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• pp.867-878
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• 2000

In order to study unsteady aerodynamic loads on high speed trains passing by each other 350km/h, three-dimensional flow fields around trains during the crossing event are numerically simulated using three-dimensional Euler equations. Roe's FDS with MUSCL interpolation is employed to simulate wave phenomena. An efficient moving grid system based on domain decomposition techniques is developed to analyze the unsteady flow field induced by the restricted motion of a train on a rail. Numerical simulations of the trains passing by on the double-track are carried out to study the effect of the train nose-shape, length and the existence of a tunnel on the crossing event. Unsteady aerodynamic loads-a side force and a drag force-acting on the train during the crossing are numerically predicted and analyzed. The side force mainly depends on the nose-shape, and the drag force depends on tunnel existence. Also. a push-pull (i.e.impluse force) force successively acts on each car and acts in different directions between the neighborhood cars. The maximum change of the impulsive force reaches about 3 tons. These aerodynamic force data are absolutely necessary to evaluate the stability of high speed multi-car trains. The results also indicate the effectiveness of the present numerical method for simulating the unsteady flow fields induced by bodies in relative motion.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집B
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• pp.599-604
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• 2000

In order to study unsteady aerodynamic loads on high speed trains passing by each other at the speed of 350km/h, three-dimensional flow fields around trains during the crossing event are numerically simulated using the three-dimensional Euler equations. The Roe's FDS with MUSCL interpolation is employed to simulate wave phenomena properly. An efficient moving grid system based on domain decomposition techniques is developed to analyze the unsteady flow field induced by the restricted motion of a train on a rail. The numerical simulations of the trains passing by on the double-track are carried out to study the effect of the train nose-shape, the train length and the existence of tunnel when the crossing event occur. Unsteady aerodynamic loads side force and drag force-acting on the train during the crossing are numerically predicted and anlayzed. It is found that the strength of the side force mainly depends on the nose-shape, and that of drag force on tunnel existence. And it is observed that the push-pull like impulsive force successively acts on each car and acts in different directions between the neighborhood cars. The maximum change of the impulsive force reaches about 3 tons. These aerodynamic force data are absolutely necessary for the evaluation of the stability of the high speed multi-car train. The results also indicate the effectiveness of the present numerical method for the simulation of unsteady flow field induced by the bodies in the relative motion.

• Archives of Plastic Surgery
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• 제46권5호
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• pp.480-483
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• 2019

Repairing surgical defects of the nose is still challenging due to its tridimensional shape and its aesthetic concern. Difficulty in reconstructing nasal subunits lies in their contour, skin texture and limited availability of adjacent skin. For lower nasal dorsum and supra-tip regions, we design a new combined local flap as existing local flaps may give disappointing results. This combination flap was performed on two patients for reconstruction of the lower nasal dorsum area after basal cell carcinoma excision. Size of the excision ranged from 20 to 25 mm diameter and safe margins were obtained. The defects were reconstructed with a local flap that combined a rotation nasal flank flap and a V-Y advancement nasolabial flap. Excision and reconstruction were performed in a one-stage surgery under intravenous sedation and local anesthesia. There were no postoperative complications and no flap loss occurred. Aesthetic and functional results after 6 months postoperatively were satisfying without modification of nasal shape. This flap is reliable and offers interesting functional and aesthetic outcomes. It can be considered as a new reconstruction alternative for supra-tip and lower nasal dorsum skin defects performed in a one-stage procedure under local anesthesia.