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

일본 윤활유업계의 현황과 과제

김영준,Kim, Yeong-Jun 대한석유협회 1983 석유와 에너지 Vol.1983 No.8

이 글은 일본윤활유업계의 실태와 기술수준, 이들 업체의 공해대책, 윤활유 공업육성을 위한 정부의 기능등을 조사 하기 위하여 지난 5월 하순 일본 자원에너지청과 일본윤활유협회, 전국석유공업협동조합,윤활기술연구소, 관련업체등을 방문하여 조사된 내용과 소감등을 소개한 것으로 국내윤활유업계가 당면하고 있는 많은 문제들에 대한 해결방안 모색에 참고가 되길 바란다. <필자 주>

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 Effect of Chemical Structure of Polyimides on the Miscibility of Polybenzimidazole (PBI)/Polyimide (PI) Blends

김영준,Kim, Young-Jun The Korean Fiber Society 1996 한국섬유공학회지 Vol.33 No.5

Miscibility of polymer blends prepared from poly(2,2(m-phenylene)-5,5'-ben-zimidazole), PBI, and aromatic polyimides(Pls) were investigated as a function of structural variations of polyimide component utilizing DSC and FTIR spectroscopy. Film and powder blend samples were prepared from the solution of PBI and PIs in N,N-dimethylacetamide(DMAc) and/or 1-methyl-2-pyrrolidinone(NMP). The miscibility of the PBI/PI blends was found to improve with increasing polarity of the polyimide component. For example, 3,3'-diaminodiphenyl sulfone(3,3'-DDS)/3,3',4,4'-benzophenone tetracarboxylic dianhydride(BTDA), 3,3'-DDS/4,4'-ox-ydiphthalic anhydride(ODPA) and 4,4'-isopropy lidene dianiline(BIS-A)/ODPA polyimide systems were miscible with PBI. However, when the polar polyimide components(C=O, O and SO ) were replaced by non-polar components such as hexafluoropropylidene group((CF ) C) miscibility was significantly reduced. Thus, immiscibility was obtained for polyimides based upon 5,5'-[2,2,2-trifluoro-1-(trifluoromethyl) ethylidene] his-1,3-isobenzofuranedione (6FDA) such as 4,4'-di-aminodiphenyl sulfone(4,4'-DDS)/6FDA,4,4'-oxydianiline(4,4'-ODA)/6FDA and BIS-A/6FDA polyimide systems. Non-hydrogen bonded solubility parameters for the PBI and Pls were estimated using group molar attraction constants(F) and group molar volume(V). The observed miscibility behavior was in good accord with the prediction of miscibility by the non-hydrogen bonded solubility parameter approach.

지역사회주민의 평생학습을 위한 도서관의 역할에 관한 연구

김영준,Kim, Young-Joon 한국문헌정보학회 2006 한국문헌정보학회지 Vol.40 No.1

21세기는 지식 정보화사회로 외부적인 환경 변화에 따라 국민들은 도서관에 다양한 기능을 요구하고 있다. 우선 전통적인 도서 보관(Container)기능에서 정보 접점(Connector) 기능을 요구하며. 정보 및 학습격차 해소를 위한 사회통합 기능과 지역단위의 인적자원개발을 위한 평생학습의 장으로서 역할을 기대하고 있다. 또한 정부 내의 환경도 교육인적자원부에 국가인적자원개발을 위한 '교육부총리제'를 도입하였으며 주5일제 및 고령화 사회에 대비한 도서관의 변화를 요구하고 있다. 지식 정보화, 주5일제, 고령화, 인적자원개발 등 평생학습사회의 새로운 패러다임과 불가분의 역학관계에 있는 도서관의 역할에 대하여 알아보고 앞으로 도서관이 추구해야 할 방향을 제시하였다. 21st century is a knowledge and information society. Keeping pace with this global environment change. people demand various roles from a library First, they demand to play a role of an 'Information Connector' rather than a traditional role of a 'Book Container'. Second, they demand to be the place of the social integration for a solution to the information and learning gap and the place for a life-long learning for HRD(Human Resources Development) by the community unit. In addition, not only introducing a system of 'Deputy Prime Minister and Minister of Education & HRD' for national HRD and 'Five-Day Week' but the advent of 'an Aging Society' demand a change of a library. This study researches roles of a library inseparably related to such new paradigms in the life-long learning society as the knowledge. information, five-day week. aging and HRD, and shows the right direction of a library to pursue in the future.

도봉산-옥정 광역철도 건설공사 중 Recharge well 공법을 이용한 터널 및 개착정거장 주변 구조물 침하방지 대책

김영준,Kim, Yeong-Jun 한국터널지하공간학회 2019 자연, 터널 그리고 지하공간 Vol.21 No.2

혈소판 농축혈장과 법랑기질 단백질이 성견 3급 이개부 병소의 재생에 미치는 영향

김영준,임성빈,정진형,홍기석,Kim, Young-Jun,Lim, Sung-Bin,Chung, Chin-Hyung,Hong, Ki-Seok 대한치주과학회 2005 Journal of Periodontal & Implant Science Vol.35 No.4

The purpose of this study was to study the histopathological correlation between the use of platelet-rich plasma and enamel matrix protein used in conjunction with xenograft. compared to a control group with regards to bone regeneration at the grade III furcation area in beagle dogs. Control group was treated with bovine derived bone $powder(Biocera^{(R)})$, and experimental I group was treated with bovine derived bone powder and Platelet-rich plasma and experimental II group was treated with bovine derived bone powder and Enamel matrix $protein(Emdogain^{(R)})$. The regeneration rate of bone formation was observed and compared histopathologically at 2. 4, and 8 weeks after surgery. The results were as follows: 1. In control group and both experimental groups. inflammatory cells were observed but, new bone formation wasn't. 2. In control group, new cementum on the notch was found in 4 weeks, less mature periodontal ligament when compared to that of experimental group was found and cementum formation was great but, regeneration couldn't be seen in 8 weeks. 3. Experimental I group. new bone formation in the area adjacent to alveolar bone and graft material surrounded by more dense connective tissue were found in 4 weeks. New bone formation up to crown portion was found and periodontal ligament was aligned functionally and cementum more mature. 4. Experimental II group, new bone formation was found under the defect area in 4 weeks and new bone formation around graft material in 8 weeks, too, and there were a number of fibroblasts, blood vessels, acellular cementum, which was less mature when compared to that of experimental I group, and dense collagen fiber like which normal periodontal ligament has in periodontal ligament of experimental II group in 8 weeks. 5. As a result of histologic finding, bone formation rate were 18.0${\pm}$7.87%(control group), 34. 05${pm}$7.25%(experimental I group), 19.33 ${pm}$5.15%(experimental II group) in 4 weeks and 21.89${pm}$1.58%(control group), 38.82${pm}$3.2(experimental I group), 37.65${pm}$9.22%(experimental II group) in 8 weeks. 6. Statistically significant ratio of bone formation was observed in experimental I group in 4 weeks and in experimental II group in 8 weeks. When experimental I group was compared to experimental II group, the ratio of bone formation in experimental I group was higher than that in experimental II group in 4 weeks(p<0.05). This results suggest that platelet-rich plasma showed more new bone formation than enamel matrix protein within 4 weeks. And use of enamel matrix protein in the treatment of periodontal bone defects starts to enhance regeneration after 8 weeks in beagle dogs.

하악전돌증환자에서 하악지시상분할골절단술 후 전산화단층촬영을 이용한 근심골편의 횡적인 변화에 관한 연구

김영준,국민석,박홍주,오희균,Kim, Young-Joon,Kook, Min-Suk,Park, Hong-Ju,Shet, Uttom Kumar,Oh, Hee-Kyun 대한악안면성형재건외과학회 2008 Maxillofacial Plastic Reconstructive Surgery Vol.30 No.3

Purpose: This study was performed to evaluate transverse changes of proximal segment after bilateral sagittal split ramus osteotomy (BSSRO) using 3-D CT in mandibular prognathism. Patients and methods: Twenty-two patients who underwent BSSRO for mandibular set-back in class III malocclusion without facial asymmetry were examined. Miniplates were used for the fixation after BSSRO. Facial CT was taken before and after BSSRO within 3 months. Frontal-ramal inclination (FRI), inter-gonial width (IGW) and intercondylar width (ICW) were measured in 3-D CT images using V-works $4.0^{TM}$ program. Student t-test was used to compare the changes between pre- and post-operative measurements using SPSS 10.0 program. Results: 1. Mean peroperative FRI value ($12.87{\pm}3.43^{\circ}$) was slightly increased to postoperative value ($14.13{\pm}3.72^{\circ}$) (p < 0.05). The average FRI increased 10.42% and the range was from $-2.46^{\circ}$ to $3.34^{\circ}$. 2. Mean peroperative IGW ($99.01{\pm}5.36$) was slightly decreased to postoperative IGW ($96.51{\pm}5.88mm$) (p < 0.05). The average IGW decreased 2.52 % and the range was from $-6.61^{\circ}$ to 0.91 mm. 3. Mean preoperative ICW ($125.01{\pm}5.30mm$) was slightly decreased to postoperative ICW ($125.40{\pm}5.45mm$) (p < 0.05). There is no significant difference between pre- and post-operative ICW. 4. There was significant correlationship between FRI difference and IGW difference (p < 0.05). Conclusions: These results indicate that the lower ramus of the proximal segment is moved inward after BSSRO procedure for mandibular set-back.