• 대한두개안면성형외과학회지
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• 제24권2호
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• pp.87-90
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• 2023

Endotracheal intubation is often necessary in the course of animal experiments, especially in craniofacial surgery. However, endotracheal intubation can be a major burden in this context. The authors performed simple and cost-saving method using a 200 µL yellow micropipette tip, and the success of this method was demonstrated by X-ray and autopsy. We used a total of 30 rats. After the rats were fixed with a plaster, the trachea and vocal cords were visualized with the tongue pulled back. Under direct visualization of the vocal cords, a curving micropipette tip was advanced into the trachea. This method can be learned quickly and applied successfully by general experimenters. We successfully intubated all 30 rats without any complications. The success rate of micropipette tip intubation was 100%. This procedure was performed by one experimenter within 2 to 3 minutes after induction of anesthesia. We demonstrated its superiority by X-ray and autopsy. Herein, we describe endotracheal intubation of rats using micropipette tips. To the best of our knowledge, this method is novel and represents the simplest and most efficient means of intubation in rats, providing an alternative to conventional endotracheal intubation.

• 한국정밀공학회지
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• 제30권6호
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• pp.615-621
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• 2013

The robot calibration has greatly improved the absolute accuracy of the industrial robot. However, the accuracy of the relative positions of robotic tool-tip at work-points on a work-piece is only slightly corrected by the robot calibration since there has been no practical method to eliminate the elements of the setup position errors at a robotic workplace. A robotic workplace calibration is demonstrated in this paper to minimize the relative position errors between a robot tool-tip and the work-point on a work-piece. The existing teaching and playback method has been developed for the robotic workplace calibration. This paper uses the work-piece fixed in a robotic work-place as measurement equipment instead of a special robot measurement equipment for the robotic workplace calibration. The positive effect of the robotic workplace calibration is supported by the results of computer simulation on an ideal robotic workplace model and an experiment at the actual robotic workplace.

• Journal of Korean Neurosurgical Society
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• 제52권4호
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• pp.300-305
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• 2012

Objective : The purpose of this study is to elucidate the anatomic relationships between the uncinate process and surrounding neurovascular structures to prevent possible complications in anterior cervical surgery. Methods : Twenty-eight formalin-fixed cervical spines were removed from adult cadavers and were studied. The authors investigated the morphometric relationships between the uncinate process, vertebral artery and adjacent nerve roots. Results : The height of the uncinate process was 5.6-7.5 mm and the width was 5.8-8.0 mm. The angle between the posterior tip of the uncinate process and vertebral artery was $32.2-42.4^{\circ}$. The distance from the upper tip of the uncinate process to the vertebral body immediately above was 2.1-3.3 mm, and this distance was narrowest at the fifth cervical vertebrae. The distance from the posterior tip of the uncinate process to the nerve root was 1.3-2.0 mm. The distance from the uncinate process to the vertebral artery was measured at three different points of the uncinate process : upper-posterior tip, lateral wall and the most antero-medial point of the uncinate process, and the distances were 3.6-6.1 mm, 1.7-2.8 mm, and 4.2-5.7 mm, respectively. The distance from the uncinate process tip to the vertebral artery and the angle between the uncinate process tip and vertebral artery were significantly different between the right and left side. Conclusion : These data provide guidelines for anterior cervical surgery, and will aid in reducing neurovascular injury during anterior cervical surgery, especially in anterior microforaminotomy.

• 대한기계학회논문집B
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• 제34권2호
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• pp.179-184
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• 2010

스트레이트 휜 히트 싱크가 장착된 공간에 팁 클리어런스(tip clearance)와 바이패스 유동이 열성능에 미치는 영향을 실험적으로 규명하고자 한다. 수평 및 수직 방향으로의 바이패스 유동에 의한 열성능 평가는 열식 질량 유량계(MFC)와 소형 풍동으로 이루어진다. 팁 클리어런스와 바이패스 유동에 의한 히트 싱크의 열성능은 열저항을 통하여 평가한다. 실험 결과, 스트레이트 휜 히트 싱크의 열저항은 팁 클리어런스가 증가함에 따라 점진적으로 증가하며, 유동 가이드 장치는 바이패스 유동을 감소하는 역할을 한다. 본 연구에서는 동일 유량 조건에서 히트 싱크의 입구에서 유동 가이드 장치까지의 거리에 따라 스트레이트 휜 히트 싱크의 최적값이 존재함을 확인하였다. 히트 싱크로 유입되는 유량이 증가함에 따라 유동 가이드 장치에 의한 열성능 개선 정도는 증가한다.

• Archives of Plastic Surgery
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• 제37권3호
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• pp.259-264
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• 2010

Purpose: Most surgeons have used autogenous cartilage for columella strut graft. But the supply of autogenous cartilage is often limited. So, this study is to investigate the usefulness of biodegradable plate as columella strut material. Methods: We studied 19 patients who have secondary cleft nasal deformity. Patients were divided into two groups. Group A patients who were not closed their growth plate underwent columella strut graft only with biodegradable plate through endonasal approach. The biodegradable plate was inserted between nasal tip and anterior nasal spine. Group B patients were closed their growth plate. They had an operation for columella strut graft with biodegradable plate fixed with autogenous conchal cartilage. If nasal tip projection was insufficient, we performed additionally onlay graft on nasal tip with autogenous soft tissue or remnant cartilage. Results: As a result of mean 14 months follow-up, we achieved a good nasal tip projection, narrowing of interalar distance and symmetrical nostril shape. No specific complications were reported except 2 cases, which were the extrusion of biodegradable plate into the nasal cavity and Staphylococcus aureus infection. Conclusion: The columella strut graft using biodegradable plate is simple and effective method. Biodegradable plate can be a good substitute for columella strut in patients who can not use autogenous cartilages.

• 한국음향학회지
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• 제37권2호
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• pp.83-91
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• 2018

팁젯 로터의 소음원은 로터 블레이드 소음과 제트 소음으로 분리할 수 있다. 로터 블레이드 소음은 두께 소음, 하중 소음, 비선형 사중극 소음으로 구성되고 제트 소음은 노즐 모멘텀 소음과 제트 방사 소음으로 나뉜다. 로터 블레이드 소음을 해석하기 위해 유동 해석 정보를 전산유체역학(Computational Fluid Dynamics, CFD) 해석으로 얻은 뒤 투과면, 비투과면 FW-H(Ffowcs Williams-Hawkings) 음향 상사법을 동시에 적용하여 각 소음원을 구분하였다. 그리고 제트 소음은 노즐 출구 조건을 활용하여 투과면 FW-H 음향 상사법으로 노즐 모멘텀 소음을 구하고 기존 고정익 제트에 대한 경험식을 활용하여 제트 방사 소음을 얻었다. 검증 기체의 소음 측정값을 기준으로 해석 기법의 신뢰성을 검증하였고 스펙트럼 분석을 통해 팁젯 로터의 독특한 소음 특성을 확인하였다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2009년도 제33회 추계학술대회논문집
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• pp.387-391
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• 2009

소형 무인항공기 추진용 덕티드 팬의 실험적 연구가 수행되었다. 이 논문에서는 덕티드 팬의 입구, 로터 뒤, 스테이터 뒤에서 허브에서 팁 방향으로 $45^{\circ}$ 경사 열선으로 측정하여 비정상 3차원 유동 특성을 연구하였다. 경사열선 요각을 고정시켜 데이터를 획득하였다. 이 데이터는 위상평균기법을 이용하여 평균되었다. 이 데이터는 Newton-Rhapson 수치해법을 통하여 3개의 비선형 연립방정식을 풀었다. 축 방향, 반경 방향 그리고 원주 방향 속도의 윤곽을 통해 팁 후류, 이차유동 그리고 팁 누설유동과 같은 유동 특성을 확인 하였다.

• International Journal of Automotive Technology
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• 제4권3호
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• pp.119-124
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• 2003

Dimethyl Ether (DME) is an excellent alternative fuel that provides lower particulate matter (PM) than diesel fuel under the same engine operating conditions. Spray characteristical of DME in common rail injection system were investigated within a constant volume chamber by using the particle motion analysis system. The injector used in this study has a single hole with the different orifice diameter of 0.2, 0.3 and 0.4 mm. The injection pressure was fixed at 35MPa and the ambient pressure was varied from 0.6 to 1.5 MPa. Spray characteristics such as spray angle, spray tip penetration and SMD (Sauter mean diameter) were measured. Spray angle was measured at 30d$_{0}$, downstream of the nozzle tip. The measured spray angie increased with increase in the ambient pressure. Increase of the ambient pressure results in a decrease of spray penetration. The experimental result, of spray penetration were compared with the predicted one by theoretical and empirical models. Increase in the ambient pressure and nozzle diameter results in an increase of SMD at a distance 30, 45 and 60d$_{0}$, downstream of the nozzle, respectively.ely.

• Archives of Plastic Surgery
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• 제41권1호
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• pp.29-34
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• 2014

The septal extension graft is a very useful method of controlling nasal lengthening and tip projection, rotation, and shape by fixing a graft to the septum, which leads to a strong supporting structure. Enhancing graft stability is important for better long-term outcomes and minimizing complications or relapse, and even more efficient application of these methods is needed for East Asians who lack enough cartilage to be harvested in addition to possessing a weak cartilage framework. In this paper, the methods for overcoming the drawbacks of the septal extension graft, such as instability, a fixed tip, and insufficiency of cartilage, are presented, and the applications of each method for greater satisfaction with surgical outcomes are also discussed.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 추계학술대회 논문집
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• pp.500-504
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• 2004

The bio-micro pin has been usually used for the biochemistry analysis. The manufacturing capability of the micro-pin and the their array with the effective and low-cost way is very important and it gives great economical benefits to developers. The micro-pin is composed of the sample channel for holding the liquid with the fixed volume, the flat tip which determines the printing quality and the pin head for preventing the rotation of the pin in the holder. In this study, we have manufactured newly designed micro-pins by the wire-EDM process with special jigs, and analyzed liquid holding and printing characteristics with respect to the variation of the shape and the tip size of the micro-pin.