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.

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

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

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.

유전 알고리즘 기반 귀납적 학습 환경을 위한 건설적 귀납법

김영준,Kim, Yeong-Joon 한국정보통신학회 2007 한국정보통신학회논문지 Vol.11 No.3

건설적 귀납법은 사례들이 갖고 있는 속성들에 적합한 연산자를 적용하여 이들 사례들을 좀 더 효율적으로 분류할 수 있는 새로운 속성들을 도출해 내는 기법이다. 본 논문에서는 주어진 사례의 집합으로부터 PROSPECTOR에서 사용한 규칙 형태의 분류 규칙을 습득하는 유전 알고리즘 기반 귀납적 학습 환경을 위한 건설적 귀납법을 제시한다. 속성 결합 연산자와 유도된 속성의 유용성을 평가하기 위한 방법을 중심으로 건설적 귀납법에 대해 자세히 설명하고 다양한 사례 집합을 이용하여 건설적 귀납법이 유전 알고리즘 기반 학습 환경에 미치는 영향을 평가하였다. Constructive induction is a technique to draw useful attributes from given primitive attributes to classify given examples more efficiently. Useful attributes are obtained from given primitive attributes by applying appropriate operators to them. The paper proposes a constructive induction approach for a GA-based inductive learning environment that learns classification rules that ate similar to rules used in PROSPECTOR from given examples. The paper explains our constructive induction approach in details, centering on operators to combine primitive attributes and methods to evaluate the usefulness of derived attributes, and presents the results of various experiments performed to evaluate the effect of our constructive induction approach on the GA-based learning environment.

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.

토석류 산사태를 고려한 터널 갱구부 설계 사례

김영준,이성기,이승훈,박동규,이승주,이동호,Kim, Yeong-Jun,Lee, Seong-Gi,Lee, Seung-Hun,Park, Dong-Gyu,Lee, Seung-Ju,Lee, Dong-Ho 한국터널지하공간학회 2012 자연, 터널 그리고 지하공간 Vol.14 No.1

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.

Substrate-immobilized bone morphogenic protein-7 peptides on titanium surface support the expression of extracellular matrix proteins

김영준,정찬길,최득철,Kim, Young-Joon,Chung, Chan-Gil,Cui, De-Zhe Korean Academy of Periodontology 2006 Journal of Periodontal & Implant Science Vol.36 No.3

이 연구는 rh BMP-7-immobilized substrates에 대한 백서 태자 두개관 세포의 반응을 석회화 결절 측정, 알카리 효소 분석, 역전사 중합반응 및 단백질 분석등으로 평가하여 다음과 같은 결과를 얻었다. 1. 배양 14일 째, 석회화 결절 형성율을 측정한 결과, rh BMP-7-immobilized substrates에서 대조군과 비교하여 더 많은 석회화 결절을 형성하였다. 2. 배양 7일에 염기성 인산 분해효소 활성도는 rh BMP-7-immobilized substrates에서 대조군에 비해 효소 활성도가 유의하게 높았다. 3. 역전사 중합반응의 결과에서 BSP 와 OCN 유전자 발현은 대조군보다 더 현저하였다. 4. 단백질 분석에서 rh BMP-7-immobilized substrates와 대조군 모두 Smad 1,5,8 단백질의 인산화를 활성화시키지 못했다. 이상의 결과 rh BMP-7-immobilized substrates는 백서 태자 두개관세포가 조골세포로의 분화와 석회화를 유도하며 따라서 rh BMP-7-immobilized substrates는 임프란트 주변의 골 형성에 유용하리라 사료된다.

기획특집-비디오 산업의 동향과 과제

김영준,Kim, Yeong-Jun 한국전자정보통신산업진흥회 1991 電子振興 Vol.11 No.8