• 전력전자학회:학술대회논문집
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• 전력전자학회 2006년도 전력전자학술대회 논문집
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• pp.206-209
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• 2006

At present, the cold cathode fluorescent lamp (CCFL) using mercury lamp has been generally used far liquid crystal backlight source of personal computer and car navigation and so on. This kind of lamp is more excellent on luminance performance and cost. However, the requirements of liquid crystal backlight due to a light source without mercury have been strongly increased from a viewpoint of the actual influence on environmental preservation and environmental recycling. As fluorescent lamp without mercury, Dielectric Barrier Discharge based rare gas fluorescent lamp (DBD-FL) using xenon (Xe) gas has been studied so far. This DBD lamp has no influence on the human body and environmental recycle. Its operating life is long because electrode is out. In this paper, the simulation and experimental results of soft switching high frequency inverter with reverse blocking single switch as a high frequency power supply circuit for DBD-FL using Xe gas are comparatively evaluated and discussed from a practical point of view.

• 한국분무공학회지
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• 제27권3호
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• pp.144-154
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• 2022

Gas injection is a technique applied to improve throttling in liquid rocket engines and atomization in effervescent injectors. When a gas is injected into a liquid, it creates a two-phase flow inside the injector. The changes (bubbly flow, slug flow, annular flow, etc.) in the two-phase flow affect the injector's spray characteristics. In this study, cold-flow tests were performed by using three injectors with different orifice diameters and four aerators with different gas injection hole diameters. The experiments were done by changing the thrust ratio (liquid mass flow rate ratio) and gas-liquid mass flow rate ratio. Two-phase flow transition, breakup length, and discharge coefficient according to the injector/aerator design and flow conditions were investigated in detail.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.1725-1728
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• 2006

Flat fluorescent lamp(FFL) is used as a light source for LCD TV backlight and is composed of many discharge channels but each channel may not be turned on simultatneouly especially at cold temperature. The simultaneous start of each lamp channels of FFL was accomplished by driving FFL with specially designed voltage and currnet waveforms without sacrificing the inverter efficency.

• 한국기계가공학회지
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• 제17권4호
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• pp.76-82
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• 2018

3D formed Electrical Discharge Machining (EDM) and hole EDM were conducted for die and mold manufacturing with electrodes which were made by mechanical machining and wire EDM. It is difficult to machine the hardened material after heat treatment and quenching with traditional machining. The only method of machining hardened material is die-sinking EDM. In this research, hole EDM was conducted for heat-treated cold-worked tool steel (SKD11) for use as a die material. The EDM surfaces were analyzed by pulse-on time and peak current of EDM current, according to the machining conditions of EDM. The EDM surface profiles were affected by the peak current. The contribution of each factor is peak current (91.63%) and pulse-on time (0.93%). The best surface roughness was obtained with a $130{\mu}s$ pulse-on time and a 14.2 A peak current. With uniform EDM processing, the surface deteriorated with increasing pulse-on time and peak current. The thickness of the solidified layer induced by EDM was increased as the peak current, crater shapes, and erupted shapes of EDM surfaces were increased. Therefore, microcracking gaps induced by surface tension were increased.

• 대한한방소아과학회지
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• 제19권2호
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• pp.31-40
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• 2005

Objectives: This study was performed to investigate the character of childhood common cold according to four seasons. Methods: We made an investigation into medical record of 432 children under fifteen years of age who visited pediatrics or emergency room suffering from common cold. We analyzed the principal and secondary symptoms of the children classifying four seasons by $SPSS^{\circledR}$ 12.0 for windows. Results: Male to female ratio were 1.42:1, the average of age was 3.86 years old. Distribution of principal symptoms was that nasal discharge was 231(56.1%), cough was 233(54.1%), nasal obstruction was 162(39.3%), secretion and sputum were 126(30.6%), fever was 121(29.4%), and headache was 13(3.2%). Out of these fever occurred in high frequency during spring and summer, nasal obstruction occurred in high frequency during spring and autumn. Distribution of secondary symptoms was that throat pain was 93(22.6%), otalgia was 39(9.5%), vomiting was 35(8.5%), abdominal pain was 30(7.3%), anorexia was 23(5.6%), sweating was 21(5.1%), diarrhea was 19(4.6%), and startle was 11(2.7%). Out of these otalgia occurred in high frequency during spring and summer, diarrhea occurred in high frequency during autumn and winter. Conclusions: A few symptoms can be the character according to four seasons.

• 대한기계학회논문집B
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• 제39권8호
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• pp.703-711
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• 2015

작업의 효율을 높이기 위해서 대형 공장에서 개구부는 주로 개방 되어 있다. 그러나 동절기에 공장에서 난방을 하는 경우 개방되어 있는 개구부는 난방부하를 상승시키는 큰 요인이다. 때문에 공장에서는 개구부 상단에 에어커튼을 설치하여 외부의 침기를 막아 난방부하를 낮춘다. 일반적인 에어커튼의 설계 변수로는 토출 각도와, 속도, 온도 등이 존재하며 이에 대한 연구는 이미 많이 진행되었다. 하지만, 공장이라는 공간적 특수성을 고려하였을 때, 기존에 연구되지 않은 개구부로부터의 이격 거리와 토출구 폭에 대한 부분도 차단 성능에 영향을 미친다. 그 결과 에어커튼은 이격 거리가 가깝고, 토출구 폭은 넓을수록 차단 성능이 좋았다. 이격 거리가 존재하더라도 토출구 폭을 증가시키면 차단 성능이 향상되었으며, 토출구 폭을 증가시킴으로써 약 13.7%의 차단 성능의 향상을 기대할 수 있다.

• 혜화의학회지
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• 제13권2호
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• pp.303-315
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• 2004

1. The acupuncture & moxibustion of hysterorrhea is focussed on bloody uterine discharge, leukorrhea and we must carefully diagnose the etiology & the machanism of disease. 2. The causes of hysterorrhea are dampness, impairment of seven emotion, irregular food intake, excessive intercourse and they are impotantly related to liver, spleen, kidney, the ren channel the chong channel 3. Using external medical treatment for Leucorrhea is washing and fumigation on vagina, to wash vagina, to insert vagina, cleansing theraphy and use with Suppository such as YONGYEOMGO(龍鹽膏), KAMISASANGJASAN(加味蛇床子散), SASANGSACHUNGSEJE(蛇床子洗劑). 4. The efficacy of medicines to use external medical treatment is as follow to helpcirculation of blood, to warm spleen and stomach, to warm blood, to warm uterus and remove cold, to remove heat and dry moisture, to down heat-product, to contract bloodvessel, to counteract poison and destory virus, to make enerey and blood.. 5. The diagnosis is grossly divided into the flowing downward of damp-heat, the weaknessof the qi of the spleen, dificiency of yuan of the kidney and according to the each diagnosis we should select adquate points representing the treatment of cooling(zhongji, yinlingquan, xingjian, etc), desiccation, heiping qi(qihai, zusanli, sanyinjiao, etc), tonificating yang (guanyuan, mingmen, shinshu, etc). 6. The moxibustion is the warming the lower jiao and eliminating the cold, the points are the mingmen point, the zhongji point, the guanyuan point, etc 7. Besides the acupuncture & moxibustion of hysterorrhea, we can make use of acusetor, ear acupuncture, endermosis, dong shi shen fa.

• 한국산업융합학회 논문집
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• 제5권4호
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• pp.367-372
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• 2002

Experimental study was conducted for lapping process after WEDMed specimen. In order to decide the lapping depth of the specimen, the number of the grain size was increased from 400, 600 to 800 to obtain the better surface. Observation of scanning electron microscope, hardness test, surface roughness test and energy dispersive spectrum(EDS) analysis were used for this experimental study. From the comparison and analyses of the results of between the wire-cut electrical discharge machining and the lapping, the following results were obtained. The surface roughness after lapping was found to be improved as increasing the number of lapping process like 1st, 2nd, 3rd lapping and the number of grain size such as 400, 600, 800. The surface hardness after increasing the lapping depth of the specimen was slowly increased. It was found that after 3rd lapping process the hardness was reached the hardness of original base material. It was found that the small amount of coating components within 3% was remained after the 1st lapping process, compared to that approximately 16% after WEDM process.

• 대한기계학회논문집
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• 제9권6호
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• pp.767-776
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• 1985

본 연구에서는 초기 조건(입구 R$_{i}$수)의 변화에 따른 속도 분포, 온도 분 포, 확산율, 계면의 변화등을 연구하며, 난류 혼합과 계면의 불안정에 기인한 속도장 과 온도장의 변화과정을 가시화 사진과 비교 분석한다.다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.261-261
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• 2012

This paper presents the understandings carried out for the installation of the hydrogen reservoir of the multi-gap pseudospark switch under developing for the accelerator applications. As a cold cold cathode switch, the pseudospark switch could replace the thyratron switch which has hot cathode and being used well currently in the high power field such as laser and accelerator applications. Especially in the klystron modulator, the key component is a switch which mostly defines the jitter and the instability of the modulator system. To get the less jitter and the instability, we need to find proper range of the pressure for the gas discharge inside gas switch. This could be achieved by the understanding of the characteristic of the nonevaporable getter (NEG) which is used as a hydrogen reservoir for the switch. Therefore we verified the characteristics of the NEG (St 172, Saes) and its installation in the switch. Finally we controlled the getter to find best pressure point for the pseudospark switch.