항공기내 연료 및 오일온도 변화에 대한 수치해석적 연구

김영준,김창녕,김철인,Kim, Yeong-Jun,Kim, Chang-Nyeong,Kim, Cheol-In 대한기계학회 2002 大韓機械學會論文集B Vol.26 No.8

A transient analysis on temperatures of fuel and oil in hydraulic and lubrication systems in an aircraft was studied using the finite difference method. Numerical calculation was performed by an explicit method with modified Dufort-Frankel scheme. Among various missions, air superiority mission was considered as a mission model with 20% hot day ambient condition in subsonic region. The ambience of the aircraft was assumed as turbulent flow. Convective heat transfer coefficient were used in calculating heat transfer between the aircraft surface and the ambience. For an aircraft on the ground, an empirical equation represented as a function of free-stream air velocity was used. And the heat transfer coefficient for flat plate turbulent flow suggested by Eckert was employed for in-flight phases. The governing equations used in this analysis are the mass and energy conservation equations on fuel and oils. Here, analysis of fuel and oil temperature in the engine was not carried out. As a result of this analysis, the ground operation phase has shown the highest temperature and the largest rate of temperature increase among overall mission phases. Also, it is shown that fuel flow rate through fuel/oil heat exchanger plays an important role in temperature change of fuel and oil. This analysis could be an important part of studies to ensure thermal stability of the aircraft and can be applicable to thermal design of the aircraft fuel system.

방사상각막신경염의 임상양상을 보인 세라티아 마르세센스 각막염 1예

김영준,김병선,유웅선,정인영,서성욱,유지명,김성재,Young Jun Kim,Byoung Seon Kim,Woong Sun Yoo,In Young Chung,Seong Wook Seo,Ji Myong Yoo,Seong Jae Kim 대한안과학회 2014 대한안과학회지 Vol.55 No.9

Purpose: To report a case of Serratia marcescens keratitis presenting as radial keratoneuritis. Case summary: A 15-year-old female who wore cosmetic and orthokeratology contact lenses but performed inadequate lens care visited our clinic with severe pain and visual disturbance in her left eye. On slit lamp examination, central corneal epithelial defect and stromal infiltration with radial keratoneuritis were observed. Based on clinical findings and past history, Acanthamoeba keratitis was highly suspected. The patient was treated with topical chlorhexidine 0.02% (Sigma-Aldrich Co., MO, USA) and moxifloxacin 0.5% (Vigamox<sup><font size=`2`>Ⓡ</font>, Alcon, TX, USA) per hour with 200 mg of oral itraconazol (Sporaone<sup><font size=`2`>Ⓡ</font>, LG, Seoul, Korea) once a day. Symptoms and corneal lesions did not improve after three days. After Serratia marsenscens was isolated from her contact lenses and solution, topical chlorhexidine 0.02% was discontinued, and intravenous ceftazidime (Tazime<sup><font size=`2`>Ⓡ</font>, Hanmi, Seoul, Korea) and fortified ceftazidime (50 mg/mL) eye drop was added. The corneal lesion dramatically improved, and after six months of follow-up, best-corrected visual acuity was 20/20 in the affected eye. Conclusions: Radial keratoneuritis can present not only in Acanthamoeba keratitis, but also in Serratia marsenscens keratitis. Confirmation of the isolated organism is useful when treating radial keratoneuritis. J Korean Ophthalmol Soc 2014;55(9):1380-1383

당뇨황반부종에서 안내 베바시주맙 치료 후 빛간섭단층촬영을 이용한 망막 혈관 직경의 변화

김영준,김형은,송원경,김성수,Young Jun Kim,MD,Hyoung Eun Kim,MD,Won Kyung Song,MD,Sung Soo Kim,MD,PhD 대한안과학회 2012 대한안과학회지 Vol.53 No.2

Purpose: To investigate retinal vascular caliber changes with Spectral Domain OCT after intravitreal bevacizumab injection in diabetic macular edema patients Methods: Thirty-four eyes of 29 diabetic macular edema patients who were intravitreously injected with bevacizumab (1.25 g/0.05 ml) were studied. Twenty-four fellow eyes of 24 patients with bevacizumab injection were also recruited as a control group. We measured retinal vascular caliber a distance of 0.5-1 disc sizes from the disc margin with Spectral Domain OCT at baseline and 1-month and 3-month follow-up visits. Central macular thicknesses were also measured. Results: Over the 3 months of study, there was a significant reduction of arteriolar caliber compared to baseline (p = 0.024), There was significant reduction of venular caliber at 1 month (p = 0.001) and 3 months (p = 0.000) compared to baseline. Venular caliber reduction at the 3-month follow-up was significantly correlated with central macular thickness (R = 0.487, p = 0.003). Conclusions: Retinal venular caliber reduction was significant at 1- and 3-month follow-up, and arteriolar caliber reduction was significant at 3-month follow-up compared to baseline. After 3 months of treatment, venular caliber reduction was correlated with reduction of central macular thickness. J Korean Ophthalmol Soc 2012;53(2):262-267

스마트폰 부품의 기술 현황 및 전망 - 중국시장과 VCM 특허로 본 스마트폰 카메라 동향

김영준,Kim, Yeong-Jun 한국광학기기산업협회 2013 光學世界 Vol.146 No.-

카메라 없는 모바일 기기는 상상할 수 없을 만큼 스마트폰 카메라가 대중화되어 있다. 모바일 기기에는 카메라가 필수 요소이며, 특히 스마트폰에는 자동초점 카메라 모듈이 기본으로 장착되어 있다. 따라서 카메라모듈 시장은 더 이상의 논의가 무의미할 정도로 전망이 아주 밝다. (그림1)은 기본적인 카메라모듈의 구조로 국내 공급업체와 증권사의 자료를 참조하였다. 스마트폰에 카메라가 기본적으로 장착되어 있는 만큼 기술적으로나 사업적으로 많은 이슈가 있다. 본고에서는 중국 시장과 자동초점 카메라모듈에 적용되는 액추에이터의 일종인 VCM(Voice Coil Motor)의 특허 분석을 통해 스마트폰 카메라의 동향에 대해서 기술하고자 한다.

The Studies on the Organization and Expression of tRNA Gene III. The Structure of the $tRNA^{Asp}$ of Aspergillus nidulans

김영준,이병재,강현삼,Kim, Young-Joon,Lee, Byeong-Jae,Kang, Hyen-Sam 생화학분자생물학회 1986 한국생화학회지 Vol.19 No.2

하등 진핵세포인 Aspergillus nidulans에서의 tRNA 유전자의 구성과 발현을 알아보기 위하여, 먼저 Aspergillus의 균사체로부터 hot phenol 방법을 수정하여 전체의 tRNA들을 추출하였으며, DEAE-cellulose column chromatography와 2차원 전개 polyacrylamide gel 전기영동을 하여 특정 tRNA를 분리시켰다. tRNA를 유출하여 $^{14}C$-aspartic acid와 charging test하여 $tRNA^{Asp}$를 고른후 [r-$^{32}P$] ATP를 사용하여 tRNA의 말단에 표지한 뒤 enzymatic partial digestion 방법에 의해 RNA의 염기순서를 결정하였다. 그 결과 anticodon은 GUC로 밝혀졌고 그 외의 tRNA의 독특한 구조와 invariable sequence들이 잘 일치하고 있는것을 보았다. Total tRNA of Aspergillus nidulans was obtained by the hot phenol extraction and DEAE-cellulose column chromatography. After separating the tRNA by two-dimensional polyacrylamide gel electrophoresis, a single tRNA was isolated and more purified. This tRNA was labeled with [r-$^{32}P$]ATP, then sequenced with base specific RNases. The RNA sequence revealed that the anticodon was GUc. This tRNA carries aspartic acid. This sequence was compared with those of the other $tRNA^{Asp}$ and some structural characteristics were found.

ATM망의 효율적 분석을 위한 MPEG 비디오 신호원에 대한 모델링

김영준,강승찬,Kim, Yeong-Jun,Gang, Seung-Chan 한국정보처리학회 2001 정보처리학회논문지B Vol.8 No.1

ATM망은 차세대 초고속 정보 통신망 구축에서 핵심적인 역할을 담당할 것이다. ATM망은 53Byte단위의 셀을 전송단위로 망의 효율을 높이고 초고속망을 지원하기 위해 하드웨어적 스위치 시스템을 가지게 될 것으로 예측한다. 이러한 망을 최적으로 관리하고 이용하기 위해서 망에 대한 모델링과 망에 입력되는 트래픽, 즉 소스에 대한 모델링이 주요한 이슈로 대두되었다. 또한 초고속 ATM망을 이용하여 차세대 영상서비스를 제공하는 것과 관련된 연구분야가 현재 활발히 진행중이다. 본 연구에서는 ATM망을 이용한 비디오 서비스에 핵심적인 역할을 담당하고 있는 비디오 신호원의 VBR 및 CBR 특성에 대한 분석과 그에 따른 새로운 모델을 제시하고자 한다.

기획특집 (1)_최신 광학기술 동향 - 자동초점 폰 카메라의 시장 및 특허 동향

김영준,Kim, Yeong-Jun 한국광학기기산업협회 2010 光學世界 Vol.125 No.-

소형 VCM 기술분야에서는 대부분의 특허를 일본이 보유하고 있다는 점이 특이점으로서 대체적으로 한국의 삼성전기와 일본의 Shicoh, Sankyo, Mitsumi Electric, Konica Minolta등이 본 기술분야를 주도적으로 이끌고 있는 주요 출원인인 것으로 나타났다. 2003년 이후부터 지속적으로 출원이 증가하였고, 2006년부터 일본 등에서 공격적으로 Hybrid type을 비롯하여 VCM 특허 출원을 진행 중이다. 공개가 2~3년 임을 감안할 때 계속해서 관련 특허 출원이 증가 될 것으로 예상된다.

3급 치근분지부 골결손에서 transforming growth $factor-{\beta}$가 치주조직의 재생에 미치는 영향에 관한 시험적 연구

김영준,Kim, Young-Joon 대한치주과학회 2001 Journal of Periodontal & Implant Science Vol.31 No.2

Transforming growth $factor-{\beta}(TGF-{\beta})$is a polypeptide biologic mediator considered to play a role in promoting bone formation in bony defect area. The purpose of this study was to examine the effect of $TGF-{\beta}$ to the periodontal regeneration of class III furcation defect in dogs. Classs III furcation defects were surgically created on the third and the fourth premolars bilaterally in the mandibles of eight mongrel dogs. Experimental periodontitis were induced by placing small cotton pellets into the created defects for 3 weeks. Experimental sites were divided into 4 groups according to the treatment modalities: Group I-Surgical debridement only; Group II-allogenic demineralized freeze dried bone grafting; Group III-allogenic demineralized freeze dried bone soaked in $TGF-{\beta}(4ng/10{\mu}l)$grafting; Group IV-allogenic demineralized freeze dried bone soaked in $TGF-{\beta}(20ng/10{\mu}l)$ grafting. The animals were sacrificed in the 8th week after periodontal surgery and the decalcified and undecalcified specimens were for histological and histometric examination. Although no significant differences was seen in the length of epitheial growth and connective attachment, group III showed the least apical migration among treatment groups. The amount of bone repair was significantly greater in group III, IV compared to group I and group II. New attachment formation was significantly greater in group III and group IV compared to group I and group II. These results suggest the allogenic demineralized freeze dried bone with $TGF-{\beta}$ in class III furcation defect has the potentiality of promoting alveolar bone formation and periodontal regeneration.

전이중 통신을 위한 자기간섭 제거 기법 구현

김영준,신진재,조현덕,윤지훈,Kim, Young-Jun,Shin, Jinjae,Cho, Hyundeok,Yun, Ji-Hoon 한국정보통신학회 2016 한국정보통신학회논문지 Vol.20 No.3

동일 주파수에서 신호의 송신과 수신을 동시에 수행하는 전이중 통신은 무선 링크 용량을 향상시킬 기술로 관심을 받고 있지만, 노드가 전송하는 시그널이 자신에게 간섭으로 작용하는 자기간섭을 억제해야 용량 이득을 달성할 수 있다. 본 논문에서는 자기간섭 제거 기법을 구현하고 이를 SDR(Software-Defined Radio) 기반의 송수신 시스템과 결합한 테스트베드 실험을 통해 제거 성능을 측정한다. 구현된 자기간섭 제거 기법은 안테나 배치 기법과 아날로그 신호 레벨에서 노이즈를 제거하는 회로 기법으로, 안테나 배치를 통한 기법의 동작 시 안테나 위치에 따른 자기간섭 제거 게인의 변화를 측정을 통해 보이고, 이 두 기법이 동시에 적용되었을 때 추가적인 게인을 얻을 수 있음을 보인다. Full-duplex communication can enhance wireless capacity by enabling simultaneous transmission and reception of the signals on the same frequency spectrum. Such a benefit, however, is only achieved when strong self-interference is well canceled below a sufficient level. To achieve this goal, there have been several approaches for cancellation, each of which is combined with digital-domain cancellation for a higher gain. In this paper, we implement two self-interference cancellation techniques and integrate them with a software defined radio-based wireless communication testbed. Two cancellation techniques (antenna cancellation and noise subtraction) are implemented and the cancellation gain is measured via real experiments. The results show that the gain of the antenna placement technique highly depends on the placement of a receiving antenna and the highest gain is achieved at the expected point, and we show that combining the noise subtraction circuit with the antenna placement further improves the cancellation gain.

대단지 아파트의 소방펌프설비 안전성 대책 시공사례 - 개별 인버터 부스터펌프 -

김영준,Kim, Yeong-Jun 한국화재소방학회 2007 한국화재소방학회지 Vol.3 No.2