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

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

연구발표논문초록 ( 촉매 ) : 팔라듐 담지촉매의 소결현상에 관한 연구

김영준,성벽파정 (정) ( Y . J . Kim,B . Sung ) 한국화학공학회 1985 춘계총회초록집 Vol.- No.-

도로터널에서 발생하는 결로의 원인과 대책방안

김영준,Kim, Yeong-Jun 한국터널지하공간학회 2022 자연, 터널 그리고 지하공간 Vol.24 No.3

3급 치근분지부 골결손에서 미세전류자극이 치주조직의 재생에 미치는 영향에 관한 실험적 연구

김영준,정현주,Kim, Young-Jun,Chung, Hyun-Ju 대한치주과학회 1997 Journal of Periodontal & Implant Science Vol.27 No.4

Several experimental studies showed that the application of small amounts of electric current to bone stimulated osteogenesis at the site of the cathode and suggests that the application of electrical currents to periodontal defects could promote bone and cementum formation. The purpose of this study was to determine the effect of direct microcurrent to the periodontal regeneration of class III furcation defects in dogs. Class III furcation defects were surgically created on the third and the fourth premolars bilaterally in the mandibles of nine mongrel dogs. Experimental periodontitis were induced by placing small cotton pellets into the created defects for 3 weeks. The experimental sites were divided into three 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 grafting and electrical stimulation. For fluorescence microscopic evaluation, calcein, oxytetracycline HCI and alizarin red were injected 2, 4 and 8 weeksfS days prior to sacrifice) after surgery. The animals were sacrificed in the 1st, 2nd, 4th and 8th week after periodontal surgery and the decalcified and undecalcified specimens were prepared for histological and histometrical examination. After the first and the second weeks, gingival recession was more severe in group I than groups II and III. After the fourth and the eighth weeks, there was no difference in the width of junctional epithelium and connective tissue attachment among the three groups, but the width of connective tissue attachment increased in group II at the eighth week, compared to the fourth week. The amount of bone repair in new attachment was significantly greater in group III, compared to groups I and II. New attachment formation was significantly greater in group III, compared to groups I and group II. These results suggest that electrical stimulation using microcurrent generator could be a useful tool for periodontal regenerative therapy in class III furcation defect.

MP3 저작권 보호를 위한 AOD 시스템의 설계

김영준,김태윤,Kim, Yeong-Jun,Kim, Tae-Yun 한국정보처리학회 2002 정보처리학회논문지D Vol.9 No.2

최근 초고속 통신망을 이용한 인터넷의 대중화와 더불어 인터넷을 기반으로 하는 전자상거래가 활발해지고 있다. 특히 인터넷을 통한 MP3 데이터 등의 멀티미디어 컨텐츠의 유통은 많은 연구의 대상이 되고 있다. 하지만 기존의 AOD(Audio On Demand) 시스템들은 실질적인 불법 복제방지와 저작권 보호에 미흡한 단점이 있다. 따라서 본 논문에서는 공개키 기반 구조(PKI: Public Key Infrastructure)에 기초하여 실질적인 불법복제방지와 저작권을 보호하는 AOD 시스템을 제안한다. 제안된 기법은 사용자의 공개키를 이용하여 MP3 데이터를 전송함으로써 전송 도중 제 3자로부터의 공격에 대응할 수 있고, 정당한 사용자 외에는 MP3 데이터를 사용하지 못하도록 함으로써 사용자와 판매자의 권리를 보장한다. In recent years, e-Commerce is very active on the Internet, especially the World Wide Web alone: with the popularization of Internet using high-speed networks. Especially, Circulation of Multimedia Contents like MP3 data if widely being focused as one of the popular researches. However, the existing models of AOD (Audio On Demand) System lack substantial illegal copy protection or copyright protection. In this paper, we propose an AOD System that guarantees substantial illegal copy protection and copyright protection based on the PKI (Public Key Infrastructure). As transmitting MP3 data using the user's public key, the proposed .method prevents the attack of dropper during transmitting data. Also, it guarantees the right of users and distributors by prohibiting illegal users from using MP3 data.

결합조직 이식술을 이용한 노출치근면의 치은피개

김영준,진유남,정현주,Kim, Young-Jun,Jin, Yoo-Nam,Chung, Hyun-Ju 대한치주과학회 1995 Journal of Periodontal & Implant Science Vol.25 No.1

Patients, who have gingival recession and complain of root sensitivity, or esthetic concerns, are candidates for root coverage. When free gingival grafting is used for complete root corverage, the results may not be entirely predictible unless the recession is shallow and narrow because a free gingival graft depends on collateral circulation from the lateral and apical parts of the recipient bed to survive over the avascular root. Various pedicle graft techniques can produce more esthetic results, but these procedures are only indicated when adequate donor tissues are available adjacent to the defect. This case report presents three cases for root coverage using the various connective tissue graft techniques. In the first case(Class III & IV), subepithelial connective tissue grafting was done and resulted in gingival coverage on the two-thirds of exposed root surface and blended with the adjacent tissue in color and texture. In the second case(Class I), connective tissue and partial thickness double pedicle graft resulted in complete coverage of denuded root surface. In the third case(Class I), recession was treated by supraperiosteal envelope technique. The root surface was covered completely and esthetically. Finally, the esthetics in both colors and tissue contours were acceptable to patients in all cases by the connective tissue grafting. However, in the case of the reduced interdental bone, the denuded root surfaces were hardly covered completely.

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.

음성 및 오디오 부호화기를 위한 저지연 윈도우 스위칭 modified discrete cosine transform

김영준,이인성,Kim, Young-Joon,Lee, In-Sung 한국음향학회 2018 韓國音響學會誌 Vol.37 No.2

본 논문에서는 음성/오디오 부호화기를 위한 저지연 윈도우 스위칭 MDCT(Modified Discrete Cosine Transform) 방법을 제안한다. 윈도우 스위칭 알고리즘을 사용하여 신호의 특성이 빨리 변하는 전이 구간에서 음질 저하를 개선하고, 저지연 TDAC(Time Domain Aliasing Cancellation)를 사용하여 알고리즘 지연을 1/2로 줄일 수 있는 MDCT 방법을 제안한다. 제안된 윈도우 스위칭 방법은 기존 윈도우 스위칭 알고리즘이 다른 길이의 중첩합(overlap-add)을 사용하는 것과 달리, 일정한 길이의 중첩합을 사용하여 알고리즘 지연을 1/2로 줄일 수 있었고, 신호의 특성에 따라 윈도우의 종류를 2개로 줄여 프레임 상태를 표현하는 정보 비트를 1 bit 감소시킬 수 있었다. 제안한 알고리즘을 MDCT 기반의 음성/오디오 부호화기인 ITU-T(International Telecommunication Union - Telecommunication) G.729.1 부호화기에 적용하여 성능을 확인하였으며, 알고리즘 지연을 절반으로 감소시키면서 동일한 음질을 유지할 수 있었다. In this paper, we propose a low delay window switching MDCT (Modified Discrete Cosine Transform) method for speech/audio coder. The window switching algorithm is used to reduce the degradation of sound quality in non-stationary trasient duration and to reduce the algorithm delay by using the low delay TDAC (Time Domain Aliasing Cancellation). While the conventional window switching algorithms uses overlap-add with different lengths, the proposed method uses the fixed overlap add length. It results the reduction of algorithm delay by half and 1 bit reduction in frame indication information by using 2 window types. We apply the proposed algorithm to G.729.1 based on MDCT in order to evaluate the performance. The propose method shows the reduction of algorithm delay by half while speech quality of the proposed method maintains same as the conventional method.