• Journal of Chest Surgery
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• v.1 no.1
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• pp.11-18
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• 1968

Author studied the possible pathogenesis of spontaneous pneumothorax and its effective treatment in 33 cases, and the results obtained as follows:1) Of the 33 cases, 15 cases were originated from pulmonary tuberculosis, 11 cases were non-tuberculous natures and 7 cases were followed by traumatic chest injuries which were not associated with a laceration of the lung or rib fractures.2) So called "Idiopathic spontaneous pneumothorax" seemed mostly to be caused by rupture of the emphy- sematous blebs.3) Spontaneous pneumothorax, in process of the pulmonary tuberculosis, seemed to be caused by the rupture of blebs which was formed with a pathological process of chronic pulmonary tuberculosis.4) Author experienced interesting cases of giant blebs which had been fully occupied the right thoracic cavity. At first, it was misdiagnosed as extensive spontaneous pneumothorax on X-ray which was revealed extensive pleural air shadow with total atelectasis of the right lung. A pneumonectomy was performed together with the giant multiple blebs.5] Generally, closed thoracotomy with water-sealed drainage is the treatment of choice in spontaneous pneumothorax. However, open thoracotomy and adequate surgical procedures should be undertaken in patients with continuous air leakage or recurrent attack of spontaneous pneumothorax.aneous pneumothorax.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.578-583
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• 2006

This paper introduces conceptual design of scroll expander-compressor unit for fuel cell. Since air discharged out of the fuel cell stack after reaction has still high pressure energy, some power can be extracted out of it by directing it to pass through an expanding device so that the extracted power can be used to drive an auxiliary compressor. For this purpose, a scroll type expander coupled to a scroll type compressor was designed: orbiting scroll of the expander and that of the compressor were made to share three of common drive pins installed in the mid frame plate, and central cavity in the mid-plate was used as a back pressure chamber to provide axial compliance for both orbiting scrolls. Performance analysis for the expander showed that the shaft power of the expander could reduce the auxiliary power consumption in the fuel cell by about one third at the scroll clearance of $10{\mu}m$.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.33 no.2
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• pp.77-82
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• 2022

Hunminjeongeum was made by the Great King Sejong, and composed of 17 consonant and 11 vowel letters. All the 28 letters were made according to the shape of vocal organ or space at the point of articulation for each letters. This review article focused on phonetic and phoniatric consideration for explanation of the designs of the middle vowel letters, especially three main vowel letters [ • (天, heaven), ㅡ (地, earth), ㅣ (人, human)] using video-fluoroscopic evaluation as well as computed tomography scanning, etc. During articulating / • / sound, a ball-like space at frontal portion of the oral cavity was found, tongue was contracted, and sound was deep (舌縮而聲深). During /ㅡ/ sound, a flat air space between oral tongue and hard palate was created. Tongue was slightly contacted neither deep nor shallow (舌小縮而聲不深不淺). During /ㅣ/ sound, tongue was not contacted and Sound is light (舌不縮而聲淺). Tongue was moved forward making longitudinal oro-pharyngeal air space. So, I'd like to suggest that we had better change the explanation drawing from a philosophical modeling to a more scientific modeling from real vocal tract space modeling during articulating middle vowels of Hunminjeongeum.

• Journal of radiological science and technology
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• v.35 no.2
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• pp.157-164
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• 2012

The purpose of this study is to analyze the dose distribution when wedge filter is used in the various tissue electron density materials. The dose distribution was assessed that the enhanced dynamic wedge filter and physical wedge filter were used in the solid water phantom, cork phantom, and air cavity. The film dosimetry was suitable simple to measure 2D dose distribution. Therefore, the radiochromic films (Gafchromic EBT2, ISP, NJ, USA) were selected to measure and to analyze the dose distributions. A linear accelerator using 6 MV photon were irradiated to field size of $10{\times}10cm^2$ with 400 MUs. The dose distributions of EBT2 films were analyzed the in-field area and penumbra regions by using dose analysis program. In the dose distributions of wedge field, the dose from a physical wedge was higher than that from a dynamic wedge at the same electron density materials. A dose distributions of wedge type in the solid water phantom and the cork phantom were in agreements with 2%. However, the dose distribution in air cavity showed the large difference with those in the solid water phantom or cork phantom dose distributions. Dose distribution of wedge field in air cavity was not shown the wedge effect. The penumbra width, out of the field of thick and thin, was observed larger from 1 cm to 2 cm at the thick end. The penumbra of physical wedge filter was much larger average 6% than the dynamic wedge filter. If the physical wedge filter is used, the dose was increased to effect the scatter that interacted with photon and physical wedge. In the case of difference in electron like the soft tissue, lung, and air, the transmission, absorption, and scattering were changed in the medium at high energy photon. Therefore, the treatment at the difference electron density should be inhomogeneity correction in treatment planning system.

• Journal of Korea Foundry Society
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• v.24 no.4
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• pp.238-248
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• 2004

고압 다이캐스팅에서 요구되고 있는 고품질의 주조를 위해, 비교적 간단한 개선 방안으로 용탕 주입 방법의 개선이 실험적으로 시도 되었으며, 그로 인해 많은 경우에 긍정적인 결과가 관찰 되었다. 특히, 냉가압 다이캐스트에서, 금형내 용탕의 예충전을 유도하는 용탕 주입의 속도 및 플렌저의 위치제어를 통해 기공율의 저하 및 그로 인한 기계적 강도의 개선 효과를 확인 할 수 있었다. 본 논문은, 그 원인과 결과 대한 연구를 위해, 상용 해석 도구인 Flow3D를 이용, 금형내 용탕의 흐름을 모델링을 통해 가시화하여 용탕의 주입속도 및 위치의 변화가 주물의 품질에 미치는 영향을 조사하였다. 용탕 주입을 위한 플런저의 속도 및 위치 제어의 변수로, 1) 금형내에 용탕의 예충전 유도를 위한 용탕 고속 주입 지연 정도, 2) 플런저의 저속운행에서 고속으로의 가속도, 3) 용탕의 예충전 동안의 플런저 속도를 선택, 그로 인한 영향을 연구 분석 하였고, 그 결과로 플런저의 속도 및 위치 조절을 통하여 금형내 갇힌 공기의 양이 줄어 들 수 있음을 알 수 있었다.

• Journal of Advanced Marine Engineering and Technology
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• v.25 no.2
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• pp.304-310
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• 2001

This paper describes the analysis of flow field using a projection finite element method. The projection scheme with a pressure correction is presented for the analysis of an incompressible Navier-Stokes flow. The projection scheme is analyzed numerically and applied to the well-known bench marking problems such as lid driven cavity. Finally, the projection scheme is applied to a flow through the automobiles front. In the automobiles cooling system, the flow through its front is very important to a cooling performance. The results show that the flow quantity increases by locating the position of bumper to the further front position of a car. And, the improvement on the suction part below a bumper achieves the more passing flow quantity. The attachment of an air dam increases passing flow quantity causing the pressure rise to the front part and the pressure drop beneath a car.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.6
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• pp.171-182
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• 2003

Tire vibration modes are known to play a key role in vehicle ride and comfort characteristics. Inputs to the tire such as impacts, rough road surface, tire nonuniformities, and tread patterns can potentially excite tire vibration. In this study, experimental modal analysis on the tire in ground contact are performed by a 3-D impact at the center of contact patch to investigate which modes of tire influence the vibration of wheel and axle. Through the experiment, the vibration transmission properties from tire to axle are examined. And we have compared the influential tire modes when the tire is excited by a vertical impact with those when excited by the 3-D impact. Additionally, the modes of ground contact tire are compared with those of the suspended tire.

• Journal of Power System Engineering
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• v.3 no.4
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• pp.28-35
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• 1999

An application of scroll compressor to the residential air conditioning and heat pump markets has generated many reliability problem, especially abnormal noise. Most of these noise problems is due to the check valve and compliance between FS(Fixed Scroll) and OS(Orbiting Scroll). FS and OS are the main parts of scroll compressor and are the main pumping part. But check valve has the role of protection of reverse rotation of OS when power is off. Check valve have several noise problems. Among them, shut down noise and valve movement noise is more than severe than any other problem. In this paper covers with these two noise problem.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.12 s.177
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• pp.16-21
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• 2005

Photonic crystals, periodic structure with a high refractive index contrast modulation, have recently become very interesting platform for the manipulation of light. The existence of a photonic bandgap, a frequency range in which the propagation of light is prevented in all directions, makes photonic crystal very useful in application where the spatial localization of light is required, for example waveguide, beam splitter, and cavity. However, the fabrication of 3 dimensional photonic crystals is still difficult process. A concept that has recently attracted a lot of attention is a planar photonic crystal based on a dielectric membrane, suspended in the air and perforated with two dimensional lattice of hole. The fabrication of Si master with pillar structure using hot embossing process is investigated for two dimensional, low-index-contrast photonic crystal waveguide. From our research we show that the multiple stamp copy process proved to be feasible and useful.

• Journal of Chest Surgery
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• v.26 no.4
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• pp.320-324
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• 1993

Congenital cystic adenomatoid malformation [CCAM] of the lung is extremely rare. The patient was 10 year old female and had no specipic signs and symptoms except right lower chest pain for 5 days ago before admission.On simple chest X-ray and thoracic CT scan, about 9x8x8cm sized, heterogenous marginal enhanced multiseparated hypodence lesion with air fluid level and gas bubbles in posterior pleural space in right lower chest .The culture result of needle aspiration of cavity was apergillus flavus. Right lower lobectomy was carried out and the result of biopsy was congenital cystic adenomatoid malformation.