• 한국항공우주학회지
• /
• 제47권6호
• /
• pp.405-413
• /
• 2019

전개형 구조물은 크기와 모양의 변형이 가능하여 수납과 이동이 용이한 장점으로 인해 우주 임무에 많이 사용된다. 특히, 우주에서 사용되는 구조물들의 경우에는 운용과정에서 직면하는 다양한 외란들을 견디기 위하여 높은 구조 강성을 가지도록 설계되어야 한다. 특히 전개형 구조물의 경우, 구조 경량화를 위하여 얇고 가벼운 소재를 사용하는 경우가 많기 때문에 전개 과정에서 발생하는 내력이나 전개 완료 상태에서의 구조 강성 등에 대한 면밀한 분석이 수행되어야 한다. 본 논문에서는 전개형 구조물 중에서 널리 사용되는 시저스 구조물에 대해 동역학적 모델을 수립하고 전개 속도, 각 조인트에 걸리는 내력 등 전개 거동을 분석한다. 또한, 구조물의 전개 완료 형상에 따른 구조 강성 변화를 분석하기 위하여 1단과 2단 두 가지 형상에 대해 모드 해석을 수행하였으며, 저차 모드의 모드 형상 및 고유 진동수 변화를 확인하고 변화의 원인을 고찰하였다.

• 한국공간구조학회논문집
• /
• 제14권1호
• /
• pp.93-99
• /
• 2014

Deployable structure is a system on which the study is being actively performed in various fields including architecture field. However, There is little study which can enhance the practicality since the interpretation condition is difficult as the unstable structure in the architecture field. In this study, the Scissors system has been focused on among the Deployable structure. The structure was developed using the Scissors system and the Mock-up test was performed. Through this, the unfolding method was proposed and the practicability was surveyed through the specific design of the Test model. Also, the structure stability was reviewed through structure analysis of Mock-up test model. and stabilizing method was proposed.

• 대한치과교정학회지
• /
• 제39권1호
• /
• pp.43-53
• /
• 2009

본 연구에서는 NiTi scissors-bite corrector를 세 가지 서로 다른 굵기 $0.018"{\times}0.025",\;0.016"{\times}0.022"$, 0.016"의 NiTi 와이어로 제작하였을 때 각각의 치아 이동 양상을 치아 이동 시뮬레이션 장치인 Calorific machine을 이용하여 3차원적으로 분석하고자 하였다. 가위교합에 이환된 상악 제2대구치 모형을 제작하고 제2소구치와 제1대구치 사이에 교정용 미니 임플랜트(orthodontic mini-implant)를 식립하여 제1대구치에 간접골성고정원을 설계하였다. 세 가지 굵기의 NiTi scissors-bite corrector를 부착하여 실험하였다. 치아의 이동 전후에 실험 모형은 computed tomography(CT)로 촬영하고 3차원 데이터로 변환하여 중첩하였다. 치아 이동 방향과 이동량을 계측하여, NiTi scissors-bite corrector 와이어 굵기에 따른 치아 이동 양상에 관한 통계적 유의성을 검정한 결과, 제2대구치 치관의 설측 이동량은 $0.018"{\times}0.025"$군(2.65 mm)이 가장 많았으며, 0.016"군(1.96 mm)과 통계적으로 유의한 차이를 보였다(p<0.05). 제2대구치 치관의 압하량은 $0.018"{\times}0.025"$군(2.35 mm), $0.016"{\times}0.022"$군(1.18 mm), 0.016"군(1.00 mm)으로 $0.018"{\times}0.025"$군이 나머지 두 군과 유의한 차이를 보였고(p<0.05), 치근의 압하량은 $0.018"{\times}0.025"$군(4.19 mm), $0.016"{\times}0.022"$군(3.29 mm), 0.016"군(2.24 mm)으로 세 군 간 모두 통계적 유의차를 보였다(p<0.05). 치아의 이동 양상을 관찰한 결과, 0.016"군에서는 제2대구치 치근의 협측 이동이 나타나지 않았다. 간접골성고정원으로 사용된 제1대구치의 고정원 소실은 0.2 mm 이하로 나타났다. 이상의 결과를 토대로 $0.018"{\times}0.025"$ NiTi 와이어로 제작한 NiTi scissors-bite corrector를 교정용 미니 임플랜트를 이용한 간접골성고정원과 함께 이용하였을 때, 최소한의 고정원의 소실과 함께 가장 큰 상악 제2대구치의 설측 이동 및 압하가 일어났다고 할 수 있다.

• 한국공간구조학회논문집
• /
• 제14권3호
• /
• pp.101-108
• /
• 2014

Recently, natural disasters such as earthquake, tsunami, typhoon and tornado are increasing, and cause huge economical loses and victim. Thus, when the disaster occurs, it is important to prepare emergency evacuation shelters for fast and easy construction compared to general building system. And, deployable structures will provide a great help for such aim. Deployable structures have the great advantage of being faster and easier to erect and dismantle compared to conventional building forms. In this study, we confirm the possibility of deployment for shelter structures using scissor structure system. First, Basic model was performed to recognize the appllicability of the deployable systems of the dome-shaped structure. Second, Advanced model that more improved inner space and deployment mechanism was confirmed.

• 한국전산구조공학회논문집
• /
• 제35권1호
• /
• pp.15-22
• /
• 2022

본 논문에서는 유한요소해석을 통한 모듈러 구조물 접합부의 힌지접합부 연구에 관하여 소개한다. 모듈러 구조물은 모듈과 모듈을 적층하는 방식으로 공사를 진행하여 단위 모듈간의 기둥 및 보의 일체성을 기대하기 어려운 특성을 가지고 있다. 그러나 현 모듈러 설계 시 이러한 구조적 특성을 무시하고 횡력에 대한 모멘트전달을 고려하여 기존 강구조와 동일한 방식으로 해석하고 있다. 더구나 모멘트접합을 체결하기위해 모듈러 외부뿐만 아니라 내부에서 볼트 체결이 이루어져 조립 후 마감을 추가하는 불합리한 상황도 발생한다. 이러한 일체성을 기대하기 어려운 특성을 고려하기 위하여 힌지접합을 활용한 모듈러구조시스템을 제안하였다. 논문에서는 기존의 모멘트접합부에서 힌지접합부로 변경하였을 때 하중의 전달을 확인하기 위하여 이전 다른 연구에서 활용되었던 가위 모델을 변형한 변형 가위 모델을 고안하여 접합부의 기본 이론을 제안·검토하였고, 기본을 바탕으로 계산된 결과는 구조해석 프로그램인 마이다스 젠과 비교하여 검증하였다. 추가적으로 기존 모멘트접합부로 설계되었던 모듈러구조물을 힌지접합부로 변경하여 부재내력 및 사용성을 검토하였다.

• International journal of advanced smart convergence
• /
• 제11권3호
• /
• pp.49-55
• /
• 2022

Hair styling has a significant influence on human social perception. An increasing number of people are learning hair styling and obtaining hair designer licenses. However, it takes a considerable amount of money and time to learn professional hairstyle and beauty techniques for hair styling. Since COVID-19, there has been a growing need for offline and video lectures due to the decline in onsite training opportunities. This study provides a field practice environment in which real hair beauty is performed in a virtual space. Further, the hairstyle that is most similar to the user's hair taken with a webcam or mobile phone is determined through an image matching system using the speeded up robust features (SURF) method. The matching hairstyle was created into a three-dimensional (3D) hair model. The created 3D hair model uses a head-mounted display (HMD) and a controller that enables finger tracking through mapping to reproduce the haircutting scissors' motion while providing a feeling of real hair beauty.

• Earthquakes and Structures
• /
• 제11권5호
• /
• pp.905-924
• /
• 2016

Several two-dimensional analytical beam column joint models with varying complexities have been proposed in quantifying joint flexibility during seismic vulnerability assessment of non-ductile reinforced concrete (RC) frames. Notable models are the single component rotational spring element and the super element joint model that can effectively capture the governing inelastic mechanisms under severe ground motions. Even though both models have been extensively calibrated and verified using quasi-static test of joint sub-assemblages, a comparative study of the inelastic seismic responses under nonlinear time history analysis (NTHA) of RC frames has not been thoroughly evaluated. This study employs three hypothetical case study RC frames subjected to increasing ground motion intensities to study their inherent variations. Results indicate that the super element joint model overestimates the transient drift ratio at the first story and becomes highly un-conservative by under-predicting the drift ratios at the roof level when compared to the single-component model and the conventional rigid joint assumption. In addition, between these story levels, a decline in the drift ratios is observed as the story level increased. However, from this limited study, there is no consistent evidence to suggest that care should be taken in selecting either a single or multi component joint model for seismic risk assessment of buildings when a global demand measure such as maximum inter-storey drift is employed in the seismic assessment framework.

• 대한음성언어의학회:학술대회논문집
• /
• 대한음성언어의학회 2003년도 제19회 학술대회
• /
• pp.181-181
• /
• 2003

Objectives : Vocal fold augmentation using injectable material is an easy and simple operation. This study is to evaluate the histology of minced and injected autologous auricular cartilage and fat graft in the augmentation of unilateral vocal fold paralysis using a canine model for two years. Study Design : A prospective study with the contralateral side of the larynx used as the control Methods : Twelve dogs were operated. At first, a piece of auricular cartilage was harvested from ear and minced into tiny chips with a scalpel and scissors. And also, a piece of fat tissue was harvested from inguinal area and minced into tiny chips with a scalpel and scissors. The minced cartilage and fat-paste (0.2ml) was injected using a pressure syringe into the paralyzed thyroarytenoid muscle under direct laryngoscopy. Two animals were sacrificed at 3 days, three at 3 weeks. two at 3 months. one at 6 months, one at 12 months, three at 24 months. Each dog underwent laryngectomy and serial coronal sections of paraffin blocks from the posterior part of the vocal fold were made. Result : There was no significant complication perioperatively and during follow-up. There was acute inflammatory findings in the graft at 3 days and 3 weeks. Only a very small proportion of the injected cartilage was absorbed due to the degenerative change and the overall volume was preserved even when the cells died out. The injected cartilage remained in the larynx until 24 months. Conclusion : The autologous cartilage implant using auricular cartilage was the ideal vocal cord augmentative material for the treatment of glottic incompetence.

• 대한소아치과학회지
• /
• 제5권1호
• /
• pp.19-26
• /
• 1978

The author studied occlusion in the primary dentition of 3~5 year old children and the materials for the present study comprised plaster model of 266 children in Seoul. The results were as followings; 1) In sagittal canine relationship, 63.9%(170 children) showed class 1 pattern, 2.3%(6 children) showed class 2 pattern, 21%(56 children) showed class 3 pattern and 12.8%(34 children) showed a different canine relationship in each side. 2) In sagittal molar relationship, 44.3% 118 children) showed class 1 pattern, 6.1%(16 children) showed class 2 pattern, 32.3%(86 children) showed class 3 pattern and 17.3%(46 children) showed a different molar relationship in each side. 3) In overjet, 87.8%(234 children) showed under 2mm. 4) 5.3%(14 children) showed crossbite and 4.6%(12 children) showed scissors-bite. 5) 21.8%(58 children) showed midline deviation. 6) Primate space was coincided with more common position of interdental space.

• 농업과학연구
• /
• 제47권4호
• /
• pp.903-920
• /
• 2020

Since its first demonstration as a practical genome editing tool in the early 2010s, the use of clustered regularly interspaced short palindromic repeat (CRISPR) along with the endonuclease Cas9 (CRISPR/Cas9) has become an essential choice for generating targeted mutations. Due to its relative simplicity and cost-effectiveness compared to other molecular scissors, i.e., zinc finger nuclease (ZFN) and transcription activator-like effector nuclease (TALEN), the CRISPR/Cas9 system has been shown to have a massive influence on genetic studies regardless of the biological kingdom. Although the system is in the process of being established, numerous protocols have already been released for the system and there have been various topics of CRISPR related papers published each year in ever-increasing manner. Here, we will briefly introduce CRISPR/Cas9 system and discuss the variants of the CRISPR system. Also, their applications to crop improvement will be dealt with mainly ornamental crops among horticultural crops other than Arabidopsis as a model plant. Finally, some issues on the barriers restraining the use of CRISPR system on floricultural crops, the prospect of CRISPR system as a DNA-free genome editing tool with efficient facilitators and finally, the future perspectives on the CRISPR system will be described.