수종 합금의 도재 결합강도

이광훈,조영범,정재헌,김희중,Lee, Kwang-Hoon,Cho, Young-Bum,Chung, Chae-Heon,Kim, Hee-Jung 대한치과보철학회 2011 대한치과보철학회지 Vol.49 No.3

Purpose: In this study, we evaluated the bond-strength between a few metal ceramic-alloys and veneered-porcelain and found if the bond strength of metal-ceramic alloy with lower gold content than the presently used gold alloy was high enough. Materials and methods: For this study, after plasticizing porcelain only for gold alloy, metal specimen was fabricated using Ni-Cr alloy and gold alloy with different gold content. Three point flexural test were performed to measure their bond-strength. Results: The bonding strength of Group 1 to porcelain was $40.62{\pm}3.32$ MPa, which was the highest (P<.05). In sequence of decreasing value, Group 2 (75%) was $37.47{\pm}1.57$ MPa, Group 3 (52%) $35.85{\pm}1.48$ MPa, Group 4 (51.5%) $35.04{\pm}1.34$ MPa, Group 5 (32%) $33.17{\pm}1.62$ MPa, Group 6 (10%) $30.75{\pm}1.21$ MPa. Bonding strength of Group 3 and Group 4 to porcelain did not show statistically significant difference with comparison to that of Group 5 (Duncan's test, P>.05), while there was a significant difference between that of Group 2, Group 3 and Group 4 and that of Group 6 (Duncan's test, P<.05). The bonding strength between gold alloy and porcelain increased according to the content of gold. In all experimental groups showed higher value than 25 MPa, which is the least value recommended by ISO 9693. Conclusion: In all groups, bonding strength was higher than 25 MPa, which is the least value of ISO9693. Therefore, it is considered that metal gold alloy with low gold content is clinically usable. 연구 목적: 본 연구는 여러 가지 금속-도재 합금의 도재결합강도를 측정하여 임상에 적용하는 것이 적절한지 평가하고자 하였다. 연구 재료 및 방법: 금속도재소부 전장관으로 가장 많이 사용되는 Ni-Cr 합금(Group 1)과 75% 금합금(Group 2) 및 최근 도재금 합금으로 판매되고 있는 52.5% (Group 3), 51.5% (Group 4), 32% (Group 5), 10% 금합금(Group 6)이 시편으로 제작되었다. 시편은 각각 5개씩 제작되었으며, 제작된 시편에 전용 도재를 소성하고 3점 굴곡 시험을 통하여 도재와 각 금속간의 결합강도를 측정하였다. 결과: Group 1의 도재 결합강도가 $40.62{\pm}3.32$ MPa로 다른 실험군의 도재결합 강도에 비해 통계학적으로 유의성 있게 가장 높은 결합강도를 보였고(P<.05), 다음으로 Group 2가 $37.47{\pm}1.57$ MPa, Group 3이 $35.85{\pm}1.48$ MPa, Group 4가 $35.04{\pm}1.34$ MPa, Group 5가 $33.17{\pm}1.62$ MPa, Group 6가 $30.75{\pm}1.21$ MPa 순으로 결합강도가 감소하였다. Group 2, 3, 4 의 도재결합 강도는 Group 6와 통계학적으로 유의성을 보여주고 있으나(Duncan's test, P<.05), Group 3과 4는 Group 5와 서로 유의한 차이를 보이지 않았다(Duncan's test, P>.05). 도재 결합 강도 차이는 금 함량이 높을수록 강도가 높았고, 모든 실험군에서 ISO 9693에서 제시하는 기준치(25 MPa)보다 높은 수치를 나타내었다. 결론: 실험에 포함된 모든 합금들이 임상적으로 사용 가능할 것으로 추정된다.

안와와 안구표면을 동시에 침범한 신경섬유종증 1예

이광훈,박진우,윤경철,Kwang Hoon Lee,Jin Woo Park,Kyung Chul Yoon 대한안과학회 2007 대한안과학회지 Vol.48 No.9

Purpose: To report a case of neurofibromatosis of the orbit and ocular surface. Methods: A 26-year-old man was admitted complaining of conjunctival mass and exophthalmos. Lisch nodules on the iris were observed in the right eye, and corneal opacity with neovascularization and conjunctival mass were detected in the left eye. Orbital computed tomography revealed diffuse infiltrating facial tumors including the left orbit, suggestive of plexiform neurofibromatosis. Results: We performed evisceration of the left eye and excision of the left orbital mass. Histopathologic examination revealed neurofibroma which was positive for S-100. No recurrence was detected during a 6-month post-operative period.

특발성 황반원공에서 유리체 단백질 발현에 관한 분석

이광훈,안재균,Kwang Hoon Lee,Jae Kyoun Ahn 대한안과학회 2012 대한안과학회지 Vol.53 No.10

Purpose: To investigate the vitreous proteomic profiles of macular hole (MH) patients compared to donor eyes and epiretinal membrane (ERM) patients. Methods: Ten donor eyes, 25 MH patients (15 MH without posterior vitreous detachment (PVD) and 10 MH with PVD), 10 ERM patients and 4 patients with vitreomacular traction syndrome (VMTS) were enrolled in the present study. The undiluted vitreous samples were obtained from all eyes. Proteins were identified using the micro-RPLC/MS/MS technique and using mass spectrometric data analysis from the IPI database. Proteins were searched for the function, subcellular location and tissue specificity using the Uniprot database. Results: The mean vitreous protein concentrations were the highest (p < 0.01) in MH patients without PVD. There were no qualitative changes according to the age of donor eyes. However, the authors newly-identified 12 proteins (i.e. vasorin) in donor eyes. Ten out of 136 proteins (7.3%) (i.e. retinoschisin) were exclusively detected in the MH samples. S100A8 was exclusively detected in eyes without PVD, whereas CD59 was exclusively detected in eyes with PVD. Conclusions: The results suggest there is a small difference in the vitreous proteomic profiles in MH patients compared to donor eyes or ERM patients, and that the expression of vitreous proteins is closely associated with the presence of PVD. J Korean Ophthalmol Soc 2012;53(10):1512-1522

수렴타입의 스테레오 영상 획득방법을 모사하는 변형평행타입에서의 주요인자의 정의

이광훈,김동욱,김성규,Lee, Kwang-Hoon,Kim, Dong-Wook,Kim, Sung-Kyu 한국광학회 2008 한국광학회지 Vol.19 No.4

스테레오 카메라를 사용하여 입체영상을 획득하는 대표적인 방법으로는 수렴 및 평행방식이 있다. 본 연구는 수렴 및 평행타입의 장점을 갖추고 자연스런 입체영상을 획득할 수 있는 평행타입 기반의 변형평행타입 입체영상 획득 방법을 사용하여 수렴방식의 입체영상 획득방법을 모사할 수 있는 인자들의 추출 및 정량적 분석을 통하여 중요 핵심인자를 정의하였다. 결과적으로 변형평행 타입에서 수렴타입을 모사할 수 있는 인자들은 스테레오 카메라의 간격, 화각 및 수렴각이고, 융합영역 내에서의 핵심인자는 수렴각의 변화이다. 결론적으로 변형평행타입으로 수렴타입을 완벽히 모사할 수 있는 인자들의 정량적 범위는 사용환경에 따라 다르며, 초점길이가 짧을 수록, 수렴각이 작을수록 근거리 물체에 대한 수렴타입과 변형평행타입의 영상좌표의 오차량은 적다. The representative alignments for taking a stereo image by using a stereoscopic camera are the toed-in and the parallel alignment. In this paper, we tried to find important factors in the process that captures the stereo image by modifying parallel type 3D camera alignment to take the same object information as, for instance, when toed-in type was used. The modified parallel type 3D camera has merits in both types. As a result, three important factors are found by simulation to be inter-camera distance, field of view and convergence angle for both types. And the change of the convergence angle is known to be the most important factor at the stereo fusible area in processing. The effective ranges of these factors to simulate perfectly toed-in type by modified parallel type are strongly dependent on a user's circumstances such as mobile, official, theater and so on. Additionally, the error of the simulation is reduced when the focal length of the stereo camera is short and the convergence angle becomes smaller.

상거리에 따른 시차량의 변화 및 깊이 정보의 왜곡에 대한 연구

이광훈,김동욱,권용무,장은영,김성규,Lee, Kwang-Hoon,Kim, Dong-Wook,Kwon, Yong-Moo,Chang, Eun-Young,Kim, Sung-Kyu 한국통신학회 2009 韓國通信學會論文誌 Vol.34 No.11b

카메라 간격, 정렬 방법 그리고 검출기의 분해능은 관찰자가 재생된 입체영상의 깊이감을 인지할 시 발생하는 깊이감 왜곡의 주된 요인들이다. 스테레오 카메라를 사용하여 시차영상을 획득할 시 고려해야 할 요소는 물체거리의 변화에 따른 상거리의 변화이다. 상거리의 변화는 시차영상 내 시차량 변화를 야기하며, 재생시 관찰자에게 왜곡된 깊이감을 제공한다. 본 논문은 상거리 변화에 따른 시차영상 내 시차량 변화 및 이로부터 야기되는 깊이감 왜곡을 정량적으로 분석하여, 상거리 변화가 깊이감 왜곡을 발생시키는 또 다른 주된 요인이 될 수 있음을 증명 하는데 연구의 초점을 두었다. In stereoscopy using stereo camera system, the representative factors inducing stereoscopic depth distortions have been reported such as the inter camera distance, the convergence angle and the depth resolution. The image distance is just known to us as a factor related in optical system. In a point of view of depth distortion, it will be a factor inducing a stereoscopic depth distortion. In this paper, we focused on the proof of our opinion that the image distance is one of the weighted factors inducing depth distortion under orthostereoscopic condition.

신개념 백라이트유닛 모델링

이광훈,지승현,김수현,윤영수,김수호,Lee, Kwang-Hoon,Jee, Seung-Hyun,Kim, Soo-Hyun,Yoon, Young-Soo,Kim, Soo-Ho 한국광학회 2010 한국광학회지 Vol.21 No.2

백라이트유닛을 더 얇고 밝게 제안하기 위하여 우리는 새로운 타입의 백라이트유닛을 시뮬레이션하였다. 도광판 상면에 미세 볼록렌즈어레이를 형성시킨다. 또한, LGP와의 매칭을 위하여 우리는 기능성 광학 시트를 시뮬레이션하였다. 일반적으로 전통적인 백라이트유닛들은 하나의 LGP와 네 개의 광학시트를 사용해왔으나 우리는 하나의 광학시트를 사용한 백라이트유닛을 시뮬레이션하였다. 설계 결과 우리의 백라이트유닛은 동일한 발광성을 달성하면서 시야각은 30% 더 좋아진 것을 밝혀내었다. In order to obtain thinner and brighter backlight units (BLU), we simulated a new-type backlight unit. A micro-lens array sheet was formed on the upper plane of the light guide plate (LGP) comprising the backlight unit. Also, in order to match with the LGP, we simulated a functional optical sheet. The conventional BLU uses one LGP and four optical sheets, but we simulated a BLU that uses one optical sheet. Simulation results have revealed that our BLU can achieve the same luminance and 30% better view angle as compared with conventional ones.

조갑진균증에 대한 Terbinafine의 치료효과

이광훈,전수일,조백기,안규중,전재복,박기범,심우영,이규석,김계정,계영철,서기석,안성구,김동석,김기호,권경술,김정애,김영근,안성구,김기홍,최지호,이재승,명기범,왕한영,원영호,김한욱,조윤화,이증훈,윤태영,김종민,김재홍 ( Kwang Hoon Lee,Soo Il Chun,원저 : 조갑진균증에 대한 Terbinafine의 치료효과 ( Efficacy o 대한피부과학회 1993 대한피부과학회지 Vol.31 No.4

진균각막염에서 치료실패의 위험인자에 대한 분석

이광훈,채홍재,윤경철,Kwang Hoon Lee,Hong Jae Chae,Kyung Chul Yoon 대한안과학회 2008 대한안과학회지 Vol.49 No.5

Purpose: To evaluate the risk factors for treatment failure in fungal keratits. Methods: A total of 109 patients with fungal keratitis, who were diagnosed by clinical findings, smears, and cultures and followed up for at least 2 months, were studied retrospectively. Age, sex, previous history of trauma, systemic diseases, corticosteroid use, previous ocular disease, features of keratitis, causative organism, and treatment results were reviewed. An initial univariate and multivariate logistic regression analysis was performed to identify and select the main prognostic risk factors. Results: Treatment was successful in 76 patients (69.7%) and failed in 33 patients (30.3%). Fusarium species was isolated in 34 eyes (40.0%), and an ulcer lesion was located in the central area of 54 eyes (49.5%). Multivariate analysis demonstrated that predictors of treatment failure were an ulcer exceeding 10 mm2 (P<0.001) and the presence of previous ocular diseases (P=0.007). Conclusions: In patients with fungal keratitis, a large ulcer size and the presence of other ocular diseases were risk factors for treatment failure.

한국성 형질세포 외음염

이광훈(Kwang Hoon Lee),송동훈(Dong Hoon Song),방동식(Dong Sik Bang) 대한피부과학회 1987 대한피부과학회지 Vol.25 No.5

We present a 40-year-old woman who had a well circumscribed, pea sized red-brown glistening erosive papule on the foreskin of clitoris for four months which had been resistant to various forms of treatment. Histopathologic examination revealed flattened epidermis with lozenge keratinocytes and watery spongiosis, In the upper dermis, dense bandlike infiltration of plasma cells, endothelial proliferation, and capillary dilatation were noted. Peroxidase-antiperoxidase stain showed polyclonal pattern of reaction in the cytoplasm of plasma cells.

시간 관점으로 본 조직이론 - `시간조직론` 정립을 위한 탐색적 서설 -

이광훈 ( Lee Kwang-hoon ) 가톨릭대학교 정부혁신생산성연구소 2016 정부와 정책 Vol.9 No.1

본 연구는 시간이란 변수를 조직연구에 도입하기 위하여 다양한 차원에서 조직이론의 시간적 의미를 고찰함을 목적으로 한다. 이를 위해 조직이론의 발달사를 시간관점으로 조망함으로써 기존의 이론적 체계와 경험적 연구들을 살펴본다. 구체적으로 고전에서 현대에 이르기까지 발전된 조직이론들을 객관적 시간관, 주관적 시간관 및 생물학적 시간관을 통해 재조명하였다. 본 연구는 미래의 조직을 분석하는데 있어 다양한 시간적 관점들을 활용할 필요성과 함께 향후 조직에 관한 시간 중심의 일반이론을 정립할 가능성을 탐색하기 위한 하나의 시도로서 의의를 지닐 수 있을 것이다. This paper reviews extant organization theories from the perspective of time. More specifically, the paper explores classic and modern organization theories as well as empirical studies, through the lens of various time views such as objective time, subjective time, biological time. The paper suggests that the possibility of constructing a `time organization theory` which attempts to incorporate time variable into organization studies.