백내장 낭외적출술을 시행한 흑색 백내장 1예

안성현(Sung Hyun Ahn),유인천(In Cheon You),조남천(Nam Chun Cho),안민(Min Ahn) 대한검안학회 2016 Annals of optometry and contact lens Vol.15 No.3

Purpose: We report a case of black cataract performed with extracapsular cataract extraction converted from phacoemulsification which was initially attempted during the operation. Case summary: A 60-year-old woman was diagnosed with brunescent cataract and phakodonesis on her right eye. Twelve years ago, she was performed with pars plana vitrectomy due to retinal detachment on her right eye. Initially, phacoemulsification was planned under the retrobulbar anesthesia; however, it was modified to extracapsular cataract extraction during the operation due to hardness of the lens. The nucleus of the lens was then removed, and hydrophilic acrylic intraocular lens was inserted in the posterior capsule. The removed lens was black with naked eyes, and firm tire-like material. The histopathologic examination revealed nonsignificant findings. Conclusions: Extracapsular cataract extraction has to be considered in case of a black cataract when severe brunescent cataract with the history of previous intraocular retinal operation is found during pre-operative examination.

rac-Me2Si(2-p-tolylindenyl)2ZrCl2 촉매를 이용한 에틸렌/1-옥텐의 공중합 특성

안성현 ( Sung Hyun Ahn ),박융호 ( Yeung Ho Park ) 한국공업화학회 2007 공업화학 Vol.18 No.5

Modified 9Cr-1Mo강 용접부에서 PWHT 시간에 따른 pitting의 거동

안성용 ( Sung Yong Ahn ),이명진 ( Myung Jin Lee ),조경목 ( Kyung Mox Cho ),강남현 ( Nam Hyun Kang ) 대한금속재료학회(구 대한금속학회) 2015 대한금속·재료학회지 Vol.53 No.11

The effect of PWHT time on the pitting behavior in NaCl solution was evaluated in the weld of Mod. 9Cr-1Mo steels. Specimens were fabricated using autogeneous gas tungsten arc welding (GTAW) and tested using various post weld heat treatment (PWHT) times (i.e., 30 min, 1 h, and 2 h). More retained δ -ferrite was produced adjacent to the fusion line than the weld center. The polarization curves shifted to low Ecorr and large Icorr, therefore decreasing the pitting corrosion resistance of the weld as the PWHT holding time increased. The ‘as-welded’ specimens showed random pitting at the martensite lath. With increasing PWHT time, pitting was also found at the δ-ferrite/tempered martensite (δ/TM) interface. This is because more coarse and dense Cr-rich M23C6 carbides were formed along the δ/TM interface than at the TM/TM interface as the PWHT holding time increased.

rac-Me₂Si(2-p-tolylindenyl)₂ZrCl₂ 촉매를 이용한 에틸렌/1-옥텐의 공중합 특성

안성현,박융호,Ahn, Sung-Hyun,Park, Yeung-Ho 한국공업화학회 2007 공업화학 Vol.18 No.5

새롭게 합성된 $rac-Me_2Si(2-p-tolylindenyl)_2ZrCl_2$ 촉매와 인디닐 리간드에 치환체가 붙어 있지 않는 상용촉매인 $rac-Me_2Si(Ind)_2ZrCl_2$ 촉매들을 조촉매인 methylaluminoxane (MMAO)를 사용하여 에틸렌/1-옥텐 공중합을 실시하였고, 반응물 내 1-옥텐의 농도를 변화시키며 얻어진 공중합체의 특성을 조사하였다. 촉매활성에 있어서 $rac-Me_2Si(2-p-tolylindenyl)_2ZrCl_2$ 촉매를 이용하여 공중합을 실시한 경우 다리구조를 가진 다른 촉매들과 달리 촉매활성이 감소하여 comonomer의 첨가에 따라 활성이 증가하는 comonomer effect는 발견되지 않았다. $^{13}C$ NMR 분석에서 공중합체에 삽입된 1-옥텐의 양은 촉매 리간드에 붙은 치환체에 의존함을 보였으며, 2-p-tolyl 치환체가 붙은 촉매로 얻어진 공중합체에서 1-옥텐 삽입량이 더 높음을 보였다. DSC, GPC 분석에서 반응물 내 1-옥텐의 농도가 증가함에 따라 공중합체의 녹는점, 결정성, 분자량이 모두 감소하였으며 $rac-Me_2Si(Ind)_2ZrCl_2$ 촉매보다 $rac-Me_2Si(2-p-tolylindenyl)_2ZrCl_2$ 촉매의 경우 녹는점, 결정성 및 분자량의 감소폭이 더 크게 나타났다. The copolymerization characteristics of a newly-synthesized catalyst, $rac-Me_2Si(2-p-tolylindenyl)_2ZrCl_2$, and its analogue, $rac-Me_2Si(Ind)_2ZrCl_2$, were examined in the ethylene/1-octene copolymerization while varying the concentration of 1-octene in the reaction mixture. The activity of $rac-Me_2Si(2-p-tolylindenyl)_2ZrCl_2$ catalyst was decreased with increase of comonomer concentration, which is different from the usual comonomer effect of the metallocene catalysts with a bridge structure. The contents of 1-octene in the copolymer from the catalyst with 2-p-tolyl substituent were higher than those from the catalyst without that substituent. The melting point, crystallinity, and molecular weight decreased with comonomer content which was more apparent for $rac-Me_2Si(2-p-tolylindenyl)_2ZrCl_2$ catalyst.

문법형태소 네트워크를 이용한 자동색인 시스템의 설계

안성현(Sung-Hyun Ahn),장재우(Jae-Woo Chang) 한국정보과학회 언어공학연구회 1995 한국정보과학회 언어공학연구회 학술발표 논문집 Vol.1995 No.10

뇌혈관 전산화단층촬영을 이용한 한국인의 연령대별 정상 눈물샘 용적의 측정

안성현,진상욱,양원석,안희배.Seoung Hyun An. MD. Sang Wook Jin. MD. Won Seok Yang. MD. PhD. Hee Bae Ahn. MD. PhD 대한안과학회 2014 대한안과학회지 Vol.55 No.10

Purpose: To determine the size range of lacrimal glands calculated from Brain CT angiography.Methods: A retrospective review of 107 CT scans of 214 orbits was performed. Aquaris Intuition Viewer software was used to calculate the volumes. Results: The mean volume of the lacrimal gland was 0.655 cm in right orbits and 0.595 cm in left orbits, 0.616 cm in men and 0.625 cm in women. There was a significant difference between right and left (<EM>p </EM>= 0.012) but no difference between men and women (<EM>p</EM> = 0.725). Linear regression analyses revealed that there was an inverse relationship between gland volume and age (Pearson r = -0.433, <EM>p </EM>< 0.001). Conclusions: This is the first study to report the normal volume range of Korean lacrimal glands as measured by CT scans. A difference was detected in the volume between right and left lacrimal glands. The volume of the lacrimal gland decreased with age, and there were no gender differences. J Korean Ophthalmol Soc 2014;55(10):1413-1417

특발망막앞막에서 수술 전 정면빛간섭단층촬영 영상과 수술 후 시력 호전과의 관계

안성현(Sung Hyun Ahn),이태은(Tae Eun Lee),유인천(In Cheon You),안 민(Min Ahn),조남천(Nam Chun Cho),정진구(Jin Gu Jeong) 대한안과학회 2018 대한안과학회지 Vol.59 No.4

Purpose: To investigate the correlation between en face optical coherence tomography and improvements in the postoperative prognoses of idiopathic epiretinal membranes. Methods: The medical records of 59 epiretinal membrane patients who had epiretinal membrane peeling between January 2005 and January 2016, and were followed up for > 12 months, were retrospectively reviewed. The preoperative en face images were divided into four sections involving three circular areas (6,000 µm diameter circle, 3,000 μm diameter circle, and 1,000 μm diam-eter circle) and one square (6,000 × 6,000 μm). The surface area where no epiretinal adhesion was present was quantified by measuring the number of black pixels using image-editing software (Adobe Photoshop CS6, Adobe Systems, San Jose, CA, USA). Then the correlations among the value of black pixels, preoperative and postoperative visual acuities, and central retinal thickness were analyzed. Results: The best-corrected visual acuity (BCVA) was significantly increased after epiretinal membrane peeling (p < 0.001), and the central retinal thickness was significantly decreased (p < 0.001). As the number of black pixels in the circles and the square in the en-face images increased, the postoperative BCVA significantly increased (r = 0.645, p < 0.001; r = 0.590, p < 0.001, respectively). Conclusions: As the nonadhesive surfaces of the epiretinal membrane and the retina in preoperative en face images became wider, the increments of the BCVA after surgery were greater. Therefore, en face optical coherence tomography can be used to predict prognosis after epiretinal membrane peeling. 목적: 특발망막앞막 환자에서 수술 전 정면빛간섭단층촬영(En Face optical coherence tomography) 영상과 술 후 예후와의 관련성에 대하여 알아보고자 한다. 대상과 방법: 2005년 1월부터 2016년 1월까지 특발망막앞막으로 진단된 후 망막앞막 제거술을 받은 환자 중 12개월 이상 경과 관찰한 환자 59명 59안의 의무기록을 후향적으로 분석하였다. 술 전 En Face 영상을 early treatment diabetic retinopathy study (ETDRS) subfields에 준하여, 3개의 원(6,000 μm diameter circle, 3,000 μm diameter circle, 1,000 μm diameter circle)과 1개의 사각형 (6,000 × 6,000 μm square), 총 4가지로 나누었고, 그래픽 편집 소프트웨어(Adobe Photoshop CS6, Adobe Systems, San Jose, CA, USA)를 통해 영상의 black pixel 값을 측정하여, 망막앞막의 유착이 없는 부위를 수치화하였다. 이후 Black pixel 값, 수술 전후 시력 및 수술 전후 중심망막두께와의 상관관계에 대하여 분석하였다. 결과: 망막앞막 제거술 후 최대교정시력은 유의하게 증가하였고( p <0.001), 중심망막두께는 유의하게 감소하였다( p <0.001). 6,000 × 6,000 μm square 및 6,000 μm diameter circle의 En Face 영상 black pixel 값이 증가할수록 수술 전후 최대교정시력 호전 정도가 증가하였으며, 이는 통계학적으로 유의하였다( r =0.645, p <0.001) ( r =0.590, p <0.001). 결론: 망막앞막 환자의 수술 전 En Face 영상에서 망막앞막과 망막의 유착이 없는 부위의 면적이 클수록 수술 후 최대교정시력의 증가량이 많았다. 따라서 망막앞막의 수술 후 시력 예후 예측 인자로서 정면빛간섭단층촬영 영상이 유용할 것으로 생각된다.

ESS 시스템 IGBT 스택의 새로운 설계 방법

안성국(Sung-Guk Ahn),강호현(Ho-Hyun Kang),김희중(Hee-Jung Kim),안길영(Gil-Young Ahn),김영근(Young-Geun Kim) 대한전기학회 2019 대한전기학회 학술대회 논문집 Vol.2019 No.7

한센병 환자의 파라핀종에 대한 수술적 치료 경험

정영인 ( Young In Jeong ),최광현 ( Kwang Hyun Choi ),주민숙 ( Mihn Sook Jue ),안성열 ( Sung Yul Ahn ),박향준 ( Hyang Joon Park ) 대한피부과학회 2015 대한피부과학회지 Vol.53 No.2

Background: Ulnar nerve palsy leads to thumb-web depression, hypothenar flattening, and inter-digital depression in patients with leprosy. To camouflage these deformities, patients used to inject paraffin or silicone oil into the areas of muscle atrophy associated with thumb-web depression and hypothenar flattening. After several years and decades, paraffinomas eventually resulted in extensive inflammatory fibrosis and recalcitrant recurrent ulcers at the injection sites. Objective: The aim of this study is to compare the results of different surgical treatments for paraffinomas in patients with leprosy, and to find out the most effective treatment method that has a low recurrence rate. Methods: Between January 2000 and December 2012, 47 patients with paraffinomas who had visited the Korean Hansen Welfare Association Hospital were enrolled to participate in the study. The number of paraffinomas was 56, and the mean age of the patients was 73 years. A retrospective evaluation of the cosmetic results and recurrence rate was performed. Results: Of the 56 surgically treated paraffinomas, 30 lesions were treated using primary closure, 20 lesions were treated with skin graft, and 6 lesions were treated with skin flap. The cosmetic outcomes, which were assessed using a four-point grading scale, were excellent in 10.7% (6/56), good in 25% (14/56), fair in 38% (21/56), and poor in 28% (15/56) of the patients. There were no significant differences among the three surgical procedures with respect to the cosmetic results. The recurrence rate was 33% (10/31) in the primary closure group, 50% (10/20) in the skin graft group, and 17% (1/6) in the skin flap group. There were no significant differences in the recurrence rate among the three surgical procedures. Conclusion: The extensive and aggressive curettage of lesions is very important to reduce recurrence rate. When the older age of the patients is considered in conjunction with the simplicity of the operation and the total operation time, primary closure is considered the treatment of choice both cosmetically and practically.(Korean J Dermatol 2015;53(2):89∼95)

창녕 영산읍성의 축성의미와 그 구조

남재우 ( Nam Jae-woo ),안성현 ( Ahn Sung-hyun ) 東亞大學校附設 石堂傳統文化硏究院 2016 石堂論叢 Vol.0 No.66

창녕의 영산읍성에 대하여 문헌자료와 그간의 조사 성과를 바탕으로 축성의 의미와 읍성의 특징과 구조에 대하여 살펴보았다. 조선시대에 축조된 읍성은 대부분 연해읍성으로서 왜구 방비를 위한 것이었다. 그런데 내지에 속하는 영산지역에 읍성이 축조된 것은 영산지역 역시 왜구의 침입이나 일본과의 관계가 활발했던 지역이기 때문이었다. 이에 성종 8년(1477) 하삼도의 축성을 논의하는 과정에서 영산지역이 양산, 밀양 등과 함께 읍성축조의 대상지역으로 선정되었다. 즉 영산지역에 읍성을 축조한 것은 내지라 하더라도 일본인이 낙동강을 따라 도달할 수 있는 지역이었기 때문에 일본에 대비하기 위한 축성이 필요했던 것이다. 읍성의 특성과 그 구조는 대략 다음과 같다. 영산읍성의 위치는 경남지역이 신라에 의해서 복속된 이 후에 축성된 성곽과 동일하며, 읍성의 배후산성은 영축산성이다. 그리고 형태는 평산성이며, 평면 형태는 전형적인 주형에 해당하는 거제 고현성과 달리 산정상부로 이어지는 부분이 상당히 좁다. 영산읍성 성벽의 축조수법은 조선시대 전기의 연해읍성과 유사하지만 지대석 기저부에 부석을 하지 않은 점은 특이하다. 이와 더불어 영산읍성과 조선시대 읍성 및 영진보성을 비교하였는데, 그 결과 이 시기의 성벽 기저부 조성은 크게 말목으로 지정한것과 원지형을 `L`자나 `□`자상으로 굴착한 뒤 내부에 할석을 채우는형태, 그리고 이 두가지를 혼용한 것 등으로 다양함을 알 수 있는데, 시기적이나 지역적인 특성은 확인되지 않는다. 조선시대 읍성 및 영진보성의 성벽 기저부는 지대석을 둔 구조이지만 조선후기에는 별도의 지대석을 두지 않고 성벽을 쌓는 방향으로 변했음을 확인하였다. 그리고 성벽의 지대석은 사직선과 수평기단으로 나누어지며, 전국에서 확인되는 것으로 보아 사직선기단에서 수평기단으로 변화한다고 보기 어렵고 한양도성 성벽의 영향일 가능성이 높음을 제시하였다. Based on excavational results, we have researched on the historical meaning of Youngsan eupseong in Changnyeong and its structural features. Eupseong, Town Wall, which had been built along the coastal area during the Joseon dynasty, had aimed to protect coastal area from japanese pirates. Thought Youngsan area weren`t coastal area, Young-San eupseong had been constructed in the same purpose. Because Changnyeong disrict had been plundered and attacked by japanese pirates who came along the Nakdong river. In 1477(8th year of king Sungjong`s reign, king`s court made decision to costruct Town Wall in Youngsan, Yangsan and Milyang. Because king and his court worried that japanese pirates were able to reach and plunder this region along the Nak dong river. The structure and features of Eupseong is as follows, Location of Youngsan eupseong is same with another Forts and Fortifications in Kyoungnam province after 5th century and Youngchuk sanseong Fortress had been located behind of eupseong. And the Town Wall was constructed between ground and mountainous area. Youngsan eupseong is different from Gohyun Town Wall in Geo-Je Island in terms of layout. Because Youngsan eupseong is becoming narrow towards the mountain area. The construction methods of wall are similar to the other Town Wall of coastal area built in the early Joseon period. we compared Youngsan eupseong with the other Town Walls and Forts of Joseon dynasty. As a results, we found two methods to strengthen the basis of wall. One is using wooden piles and the other is making foundation bed by digging the ground with the L or □ shapes and filling up the pit with rocks. In terms of construction technique of Town Wall of Joseon dynasty, foundation stones had been usually installed on the fundus of walls in the early time. But the technique had been changed and the foundation stones had been disappeared. Stylobate of the Wall had been constructed into two types of shape. One is diagonal shape and the other is horizontal shape. In the Youngsan eupseong, we had found both shapes of stylobate. And the diagonal shape stylobate was a rusult of influence from the Capital Fortress of Hanyang in Joseon dynasty.