• 한국광학회지
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• 제9권5호
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• pp.291-299
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• 1998

고화질 프로젝션 TV에서 광학부품들이 가격 및 성능면에서 경쟁력을 갖춘 최적의 시스템을 설정하고, 그로부터 현재 방송규격인 NTSC 및 향후에 시행될 디지털 TV에 공용적용할 투사렌즈를 설계 개발 하였다. 플라스틱 렌즈 2매와 구면 glass 렌즈 1매로 구성된 투사렌즈에 대해, 3차 수차가 모두 보정된 초기설계치로부터, 플라스틱 렌즈의 비구면화, 공차를 고려한 최적화 설계, 그리고 온도보상등의 과정을 통해 설계 하였다. 최종적으로 개발된 렌즈의 구현가능한 화면크기는 40∼50인치, 해상도는 800TV-line 이상 이다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.777-780
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• 2005

The global consumption of aspheric surfaces will expand rapidly on the Electronics and Optical Components Information and Communications, Aerospace and Defense, and Medical optics markets etc. We must research on market, technology forecast and analysis of aspheric surfaces that is a principle step of ultra precision machine technology with a base one of optical elements. Especially, F-theta lens is one of the important parts in LSU(Laser scanning unit) because it affects on the optical performance of LSU dominantly. The core is most of important to produce plastic F-theta lens by plastic injection molding method, which is necessary to get the ultra-precision aspheric and non-axisymmetric machine processing technology.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 춘계학술대회논문집
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• pp.240-243
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• 2003

Finite element analyses for bursting failure prediction in bulge forming under combined internal pressure and independent axial feeding are carried out. By means of the FEM combined with Oyane's ductile fracture criterion based on Hills quadratic plastic potential, the forming limit and bursting pressure level are investigated for a seamed tube that comprises of weldment, heat affected zone(HAZ) and base material parts. Especially, in order to determine the material property of HAZ tensile tests for the base material and the weld metal are executed based on iso-strain approach. Finally, through a series of bulge forming simulations with consideration of the weldment and HAZ it is concluded that the proposed method would be able to predict the bursting pressure and fracture initiation site more realistically, so the approach can be extended to a wide range of practical bulge forming processes.

• 대한두개안면성형외과학회지
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• 제24권1호
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• pp.1-9
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• 2023

This article, which comprises the third part of a series on surgical anatomy for Asian rhinoplasty, addresses the lower one-third of the nose, including the alar cartilage and tip-supporting structures, known as distal mobile framework. As discussed in earlier parts of this series, diversity in surgical anatomy results in different surgical techniques in Asian rhinoplasty compared to rhinoplasty in Caucasian patients. Nasal tip structures are especially important due to their crucial importance for changing the nasal shape in Asians. This article, along with the previous ones, will provide both basic and advanced knowledge of practical surgical anatomy for Asian rhinoplasty.

• Archives of Reconstructive Microsurgery
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• 제11권1호
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• pp.73-77
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• 2002

Medical application of leeches, by means of leech's blood suction, has advantages in not only directly removing blood congestion, but also preventing hindrance to venous drainage by inhibiting local thrombus formation and inducing continuous bleeding. Nevertheless, Aeromonas hydrophila infection secondary to such suction is most common and may develop into serious conditions from local inflammatory reaction to total necrosis of replanted parts and enterocolitis as well as sepsis. Once infected, it requires infection treatment, removal of necrotic tissues and reconstruction. Hence, duration and cost of treatment increase while functional recovery falls markedly. Accordingly, we present measures to reduce Aeromonas infections as follows: First, do not manipulate as much as possible while the leeches are sucking or moving. Second, the site which suction plates of the leeches are attached, should be selected away from the surgical wound site or open wound as much as possible. Third, contaminated or blood-wet gauze should be replaced often so that the skin of surgical areas would not swell. Furthermore, bleeding or oozing should be well-drained. Fourth, the areas other than the sites of leech attachment should be covered with sterilized gauzes in order to limit leech movement.

• 한국포장학회지
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• 제11권2호
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• pp.109-114
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• 2005

This paper introduces the current status of total overseas packaging industries. The total market of the world packaging industry reached over 500 billion dollars in 2002. The top nations for the packaging industry were U.S. at about 27 percent, the countries of Western Europe at about 27%, Japan at about 14%. In terms of packaging materials, the overall market rate for paper, plastics, and metal parts in world packaging industry was 84%. Also, the market rate of glass, packaging machine, and others was only 5-6%. Among EU nations, Germany showed largest packaging consumption of 23 percent in 2000, and consumed about 17,125,814 ton of packaging materials yearly. For paper and paperboard cartons, the percentage used for the packaging consumption was about 39.4%. The consumption rate of plastic and glass packaging was approximately 14.6% and 23.7% respectively. For metal packaging the consumption rate was about 5.9%. In Japan, the production rate of packaging materials was decreased slowly at paper, metal, glass, and wood areas, but plastic packaging showed a constant rate of growth. In China, total production of packaging industry amounted to about 33.7 billion in 2003. The paper packaging in china was a remarkable production rate of 32%. The production rate of plastic and printing packaging was 28% and 20% respectively. The rate of packaging industry for printing in China was much higher than that in other countries.

• 한국정밀공학회지
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• 제21권2호
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• pp.27-34
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• 2004

In the injection molding of plastic optical lenses, the molding conditions have critical effects on the quality of the molded lenses. Since there are many molding parameters involved in injection molding process, determination of the molding conditions for lens molding is very important in order to precisely control the surface contours of an optical lens. Therefore this paper presents the application of neural network in suggesting the optimized molding conditions for improving the quality of molded parts based on data of FE Analysis carried out through CAE software, Timon-3D. Suggested model in this paper, which serves to learn from the data of FE Analysis and induce the values for optimized molding conditions. has been implemented for searching the molding conditions without void and with minimized thickness shrinkage at lens center of injection molding optical lens. As the result of this study. we have confirmed that void creation at the inside of lens is primarily determined by mold temperature and thickness shrinkage at center of lens is primarily determined by the parameters such as holding pressure and mold temperature.

• 한국산학기술학회논문지
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• 제4권3호
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• pp.164-167
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• 2003

본 연구에서는 무선부품의 일종인 cavity filter금형을 제작하여 도금용 ABS 수지와 PC/ABS alloy 수지를 사용하여 일반사출성형과 금형온도가 높은 MmSH방식, 두 타입으로 성형품을 제작하였다. 성형품의 수축률 변화는 MmSH 방식일 때 ABS 성형품의 단위캐비티 격막부분에서 수축률이 감소되었다. 중량변화는 ABS와 PC/ABS 성형품 모두 MmSH 방식일 때 증가하였고, 성형품 표면 거칠기는 MmSH 방식일 때 모두 거칠기가 감소되었다.

• 대한두개안면성형외과학회지
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• 제17권4호
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• pp.240-243
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• 2016

Perfect facial and body symmetry is an important aesthetic concept which is very difficult, if not impossible, to achieve. Yet, facial asymmetries are commonly encountered by plastic and reconstructive surgeons. Here, we present a case of posttraumatic facial asymmetry successfully treated with a unique concept of facial flap repositioning. A 25-year-old male patient visited our department with severe posttraumatic facial asymmetry. There was deviated nasal bone and implant to the right, and the actual facial appearance asymmetry was much more severe compared to the computed tomography, generally shifted to the right. After corrective rhinoplasty, we approached through intraoral incision, and much adhesion from previous surgeries was noted. We meticulously elevated the facial flap of both sides, mainly involving the cheeks. The elevated facial flap was shifted to the left, and after finding the appropriate location, we sutured the middle portion of the flap to the periosteum of anterior nasal spine for fixation. We successfully freed the deviated facial tissues and repositioned it to improve symmetry in a single stage operation. We conclude that facial flap repositioning is an effective technique for patients with multiple operation history, and such method can successfully apply to other body parts with decreased tissue laxity.

• 농업과학연구
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• 제33권2호
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• pp.107-114
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• 2006

An all-aluminum radiator made of aluminum was more excellent on environment friendliness, productivity, and cooling efficiency than the plastic tank radiator which was currently widely used in same size as above. A newly designed and manufactured radiator with all parts made of aluminium was ready to re-use without any disassembly process in recycle system so as to improve environment friendliness with low waste cost. Several manufacturing processes of the current plastic tank radiator such as O-ring inserting, and clinching of core to the tank, were eliminated on the manufacturing processes of the all-aluminium radiator, which would increase productivity and reduce production cost. Design criterion of all-aluminum radiator was presented by carrying out theoretical analysis of cooling capacity and there was no difference between analytical data and measurements. Cooling capacity of the all-aluminum radiator increased generally 13% up compared with the plastic radiator even though the pressure drop of air increased.