• Computational Structural Engineering
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• v.12 no.1
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• pp.27-34
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• 1999

독자적인 자동차 충돌해석용 프로그램 개발 및 응용기술을 목표로 Explicit 수식화, 셀 요소의 정식화, 교체요소의 정식화, 비선형스프링 요소의 개발, 초탄성 고무재료의 개발, Hourglass 제어, 접촉알고리즘 정식화 등의 프로그램의 기본 모듈을 구성하였고, 그래프 출력용 포스트 프로그램을 개발하였다. 비선형스프링, 에어백 모듈, 안전벨트 모듈 등이 개발되었으며, 자체구조물들의 정면·측면 충돌해석을 수행하고 상용충돌해석프로그램들과 그 결과를 비교하여 개발된 프로그램의 신뢰성을 확인하였다. 또한, 측면충돌 모델을 사용하여 설계초기단계에서 빠른 해석을 수행할 수 있도록 하는 Hybrid 모델링 기법을 개발하여 기존의 쉘모델의 결과와 비교·검토하였다. Hybrid 모델링시 조인트 부의 특성을 측면해석 모델에 적용하여 그 타당성을 검증하였다.

• Journal of Korean Neurosurgical Society
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• v.64 no.1
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• pp.136-141
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• 2021

The crossing Y-stent method is one of the indispensable techniques to achieve sufficient neck coverage during coil embolization of bifurcation aneurysms with a wide neck and/or branch incorporation. However, the inevitable hourglass-like expansion of the second stent at the crossing point can result in insufficient vessel wall apposition, reduced aneurysm neck coverage, delayed endothelialization, and subsequent higher risks of acute or delayed thrombosis. It also interferes with engagement of the microcatheter into the aneurysm after stent installation. We expected to be able to reduce these disadvantages by installing a noncrossing type Y-stent using the Solitaire AB stent, which is fully retrievable with a tapered proximal end. Here we report the techniques and two successful cases.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2022.11a
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• pp.106-108
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• 2022

이미지 기반 3D 형상 복원에 있어서, 이미지에 보이지 않는 폐색(Occlusion) 영역 부분에 대한 정보가 손실되므로 완전한 복원에 어려움이 있으며, 세밀한 텍스쳐(Texture) 표현이 이루어지지 않고 심한 평활화(Smoothing)나 고립된 노이즈 메쉬(Isolated Noise Mesh) 등 구조적 훼손이 발생한다. 주로 깊은 신경망을 이용하여, 음함수(Implicit Function) 기반 방법은 사전훈련이 완료된 보조 신경망들을 전면부에 배치하거나, Hourglass 등 임베딩(Embedding) 아키텍처를 추가하거나, 또는 표면 법선(Surface Normal)과 같은 환시(Hallucination)를 생성하여 신경망에 입력하기도 한다. 이 논문에서는, 인물의 이미지를 입력받아 색상, 머리카락 및 의상을 포함하는 완전 3D 인간 복원 기술들을 조망해본다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2021.06a
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• pp.180-182
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• 2021

본 논문은 눈 랜드마크 위치 검출과 시선 방향 벡터 추정이 하나의 딥러닝 네트워크로 통합된 시선 추정 네트워크를 제안한다. 제안하는 네트워크는 Stacked Hourglass Network[1]를 백본(Backbone) 구조로 이용하며, 크게 랜드마크 검출기, 특징 맵 추출기, 시선 방향 추정기라는 세 개의 부분으로 구성되어 있다. 랜드마크 검출기에서는 눈 랜드마크 50개 포인트의 좌표를 추정하며, 특징 맵 추출기에서는 시선 방향 추정을 위한 눈 이미지의 특징 맵을 생성한다. 그리고 시선 방향 추정기에서는 각 출력 결과를 조합하고 이를 통해 최종 시선 방향 벡터를 추정한다. 제안하는 네트워크는 UnityEyes[2] 데이터셋을 통해 생성된 가상의 합성 눈 이미지와 랜드마크 좌표 데이터를 이용하여 학습하였으며, 성능 평가는 실제 사람의 눈 이미지로 구성된 MPIIGaze[3] 데이터 셋을 이용하였다. 실험을 통해 시선 추정 오차는 0.0396 MSE(Mean Square Error)의 성능을 보였으며, 네트워크의 추정 속도는 42 FPS(Frame Per Second)를 나타내었다.

• Korean Journal of Veterinary Service
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• v.46 no.4
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• pp.363-368
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• 2023

Patent ductus arteriosus (PDA) in monkeys is very rare. A 9-year-old male Japanese macaque (Macaca fuscata) had an hourglass-shaped PDA with a large luminal diameter. Morphological analysis of the vessel cast and heart revealed cardiovascular pathological changes including pulmonary artery hypertension and right ventricular hypertrophy. However, left ventricle hypertrophy or left atrial enlargement were not observed. This macaque had showed no clinical signs of PDA during its lifetime. We present the first documented case of solitary PDA in a male macaque.

• Journal of the Korean Society of Costume
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• v.28
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• pp.65-84
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• 1996

The purpose of this study is to analyze the relation between the beauty of human body and the fashion illustration in each period And I attained my object through the investigation of features and changes of illustration which is given a vivid description of the features and development of ideal humam body beauty. By various methods I studied this subject. Frist I refered to sundry records Secondly I investiated the fashion illustrations which are included in Vogue. On the basis of this data I grasped the ideal types of human body beauty which is founded during the social change in each 10 years. And I analyzed the relation be-tween the ideal type and fashion illustration which show the change of fashion. The summary of result is as follows. 1. In the early part of the 20th century the beauty of human body is represented with the figure of large-sized beauty which emphasize shoulder and bust. And fashion ikllustration show 9 life-size broad shoulder full bust lim waist and hourglass silhouette. 2, In the 1910s the swell of strength vanishes gradually and shoulder and sleeve are straight type. And fashion illustration show 7 life-size high waist line. And that is tublar sil-houette of high waist and streamline shape in which bust and hip are not emphasized. 3. In the 1920s the ideal type of human body beauty is straight type which shows flat bust and unexaggerate hip. And fashion illus-tration is about 8 life-size tublar silhouette of low waist and lunger and slimmer and young style in which bust and hip are not emph-asized. 4. In the 1930s the ideal is womamly slim and long style. Fashion illustration is about 8 life-size and slim & long silhouette in which waist line is emphasized and bust and hip line come out. 5. In the 1940s the ideal type is womamly style which has narrow shoulder rich bast and slim waist. And fashion illustration is about 7 life-size and hourglass silhouette which has unartificial shoulder slim waist and empha-sized bust. 6. In the 1950s the ideal type is that of ro-bust health which emphasize build and muscu-lar system. And fashion illustration is 8.5 life-size and show full bust and made waist slimmer. That is sheath silhouette. 7. In the child who has full face with large eyeball slender and long leg: narrow and immatured body comparatively big head. And fashion illus-tration is 7 life-size and show slim and long neck flat bust long and slim limbs and big head. That is H type silhouette. 8. In the 1970s the ideal type is high stat-ure flat breast small hip and wide shoulders. And fashion illustration is wide shoulders and slim waist as 11 life-size and straight sil-houete. 9. In the 1980s the ideal type is extremely emphasized breadth of shoulder because healthy body and muscle are recognized as the symbol of ideal attractiveness. And fashion il-lustration is about 8.5 life-size and show mus-cular slim type that is slim silhouette. 10 At the present time the ideal type is slim and tall type which is empasized healthy beauty. And fashion illustration is 12 life-size which has healthy body and skin So that is slim and long type.

• Journal of Chest Surgery
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• v.36 no.6
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• pp.448-450
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• 2003

Lipoma is a circumscribed mesenchymal tumor originating from the adipose tissue. The lesion is usually small and asymptomatic. The most common location is in the neck region, however, lipoma can be found in the mediastinum in rare occasions. Although lipoma reach to the large proportions in the mediastinum, it rarely compresses the neurovascular structure. We present a case of a 58-year-old man, in which a hourglass-type cervicomediastinal lipoma produced Horner's syndrome with voice change. The man presented a swelling at the right side of his neck, ptosis and anhidrosis on the right side of his face, and right chest discomfort. After the removal of the mass, all the symptoms which had been provoked by compression, as well as Horner's syndrome and hoarseness, nearly disappeared.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.18 no.4
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• pp.271-281
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• 2008

This study is to characterize the occurrence types and mineralogical characteristics of asbestos for the Kwangcheon areas, Chungnam. The mine areas had been exploited as asbestos mines for several decades since 1930. Host rocks of the asbestos are serpentinites and altered rocks of the ultramafic rocks. Representative samples of the host rocks and minerals were sampled and were examined with microscopes. To confirm for the existences and compositions for the asbestos, the rock samples were analysed with EPMA, XRD and EDS. Chrysotile, tremolite and actinolite were found as asbestos and non-asbestos forms in these areas. Chrysotiles, as non-asbestos forms, occur in the host rocks with mesh and hourglass textures. They, as asbestos forms, are mainly found as the veins. The tremolite and actinolite, as asbestos types, occur as alteration products of the olivine and pyroxene within the host rocks. They, as asbestos types, are also found following the cracks and fractures. Overall results suggest that three types of the asbestos are found in the Kwangcheon and Kaewol mine areas. Based on the occurrence types for the asbestos, additional studies are required for the asbestos in the top soil and air.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2000.10a
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• pp.42-48
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• 2000

This paper is concerned with a simulation-based process design for the tension levelling of metallic strips based on the elasto-plastic finite element analysis with reduced integration and hourglass control. The tension levelling process is performed to elongate the strip plastically in combination of tensile and bending strain by a controlled manner so that all longitudinal fibers in the strip have an approximately equal amount of length and undesirable strip shapes are corrected to the flat shape. The analysis deals with a method for calculating the quantitative level of the curl to investigate the roll arrangements and intermesh suitable to elimination of the curl. The analysis provides the information about the intermesh effect on the amount, the tension effect and distribution of the strain as well as the stress in order to determine the amount of elongation for correction of the irregular shape. The desired elongation is referred to determine the number of work rolls and the value of tension. Especially, the analysis investigates tile effect of the mesh size in the non-steady state finite element analysis on the amount and distribution of the strain.

• Structural Engineering and Mechanics
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• v.21 no.5
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• pp.539-551
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• 2005

Finite elements based on isoparametric formulation are known to suffer spurious stiffness properties and corresponding stress oscillations, even when care is taken to ensure that completeness and continuity requirements are enforced. This occurs frequently when the physics of the problem requires multiple strain components to be defined. This kind of error, commonly known as locking, can be circumvented by using reduced integration techniques to evaluate the element stiffness matrices instead of the full integration that is mathematically prescribed. However, the reduced integration technique itself can have a further drawback - rank deficiency, which physically implies that spurious energy modes (e.g., hourglass modes) are introduced because of reduced integration. Such instability in an existing stiffness matrix is generally detected by means of an eigenvalue test. In this paper we show that a knowledge of the dimension of the solution space spanned by the column vectors of the strain-displacement matrix can be used to identify the instabilities arising in an element due to reduced/selective integration techniques a priori, without having to complete the element stiffness matrix formulation and then test for zero eigenvalues.