미세각막절개도를 이용한 데스메막박리 각막내피층판이식술의 국내 장기 임상 결과

이준성,박영걸,윤경철,Jun Sung Lee,Yeoung Geol Park,Kyung Chul Yoon 대한안과학회 2010 대한안과학회지 Vol.51 No.11

Purpose: To evaluate the long-term results of Descemet’s stripping automated endothelial keratoplasty in Korea (DSAEK). Methods: Seven patients with bullous keratopathy who underwent DSAEK and who were followed-up for more than 18 months were reviewed retrospectively. Best corrected visual acuity, refraction, corneal thickness, and endothelial cell count were examined before and after surgery. Results: The mean follow-up period was 19.9 ± 2.9 months (18 to 24 months), and the mean age was 61.42 ± 10.13 years (46 to 76 years). Six patients (85.7%) showed successful results after surgery. Best corrected visual acuity (logMAR) was significantly improved from 1.62 (median) to 1.15 (median) (p = 0.027) at one month after surgery and was maintained until the final follow-up period. There were no statistical differences in spherical ametropia or astigmatism before or 18 months after the operation. Graft failure was observed in one case, in which penetrating keratoplasty was performed 12 months after DSAEK. Conclusions: Long term results of DSAEK showed fast visual recovery, low ametropia and astigmatism. DSAEK may be a good option for the surgical management of corneal endothelial disease. J Korean Ophthalmol Soc 2010;51(11):1431-1437

확률론적 파괴역학을 도입한 CANDU 압력관의 예리한 결함에 대한 건전성평가

이준성,곽상록,김영진,박윤원,Lee, Jun-Seong,Gwak, Sang-Rok,Kim, Yeong-Jin,Park, Yun-Won 대한기계학회 2002 大韓機械學會論文集A Vol.26 No.4

This paper describes a probabilistic fracture mechanics(PFM) analysis based on Monte Carlo(MC) simulation. In the analysis of CANDU pressure tube, the depth and aspect ratio of an initial semi-elliptical surface crack, a fracture toughness value and delayed hydride cracking(DHC) velocity are assumed to be probabilistic variables. As an example, some failure probabilities of piping and CANDU pressure tube are calculated using MC method with the stratified sampling MC technique, taking analysis conditions of normal operations. In the stratified MC simulation, a sampling space of probabilistic variables is divided into a number of small cells. For the verification of analysis results, a comparison study of the PFM analysis using other commercial code is carried out and a good agreement was observed between those results.

건성안 환자에서 쇼그렌증후군의 빈도 및 임상양상

이준성,최원,이신석,윤경철.Jun Sung Lee. MD. Won Choi. MD. Shin Seok Lee. MD. Kyung Chul Yoon. MD. PhD 대한안과학회 2012 대한안과학회지 Vol.53 No.4

Purpose: To investigate the prevalence and clinical aspects of Sjögren syndrome in patients who were diagnosed with dry eye syndrome in Korea. Methods: The medical records of patients who were diagnosed with dry eye syndrome in a dry eye clinic during a 2-year period (March 2008 to March 2010) and were followed up for more than 3 months were reviewed retrospectively. Results: A total of 206 patients were included in the present study. Fifty-eight patients (28%) had Sjögren syndrome and 39 patients (19%) showed primary Sjögren syndrome. Sjögren syndrome patients showed poorer results than non-Sjögren syndrome patients in ocular surface disease index score (OSDI), tear break up time, Schirmer test score, and ocular surface staining score using the Oxford scheme (p < 0.05). Among the patients with primary Sjögren syndrome, 27 patients were SSA (anti-Ro antibodies) or SSB (anti-La antibodies) positive and 12 patients were sero-negative. There were no statistically significant differences in objective or subjective parameters between the sero-positive and sero-negative groups. Conclusions: Sjögren syndrome was observed in 28% of all dry eye patients, in two-thirds of severe dry eye patients. Sjögren syndrome patients showed more severe clinical aspects than dry eye patients with non-Sjögren syndrome. Diagnosing Sjögren syndrome through systemic evaluation is necessary in the patients with severe dry eye. J Korean Ophthalmol Soc 2012;53(4):499-504

결정질 실리콘 태양전지용 실리콘 기판의 표면 미세구조에 따른 곡강도 특성

이준성,권순우,박하영,김영도,김형준,임희진,윤세왕,김동환,Lee, Joon-Sung,Kwon, Soon-Woo,Park, Ha-Young,Kim, Young-Do,Kim, Hyeong-Jun,Lim, Hee-Jin,Yoon, Se-Wang,Kim, Dong-Hwan 한국재료학회 2009 한국재료학회지 Vol.19 No.1

The influence of various surface morphologies on the mechanical strength of silicon substrates was investigated in this study. The yield for the solar cell industry is mainly related to the fracturing of silicon wafers during the manufacturing process. The flexural strengths of silicon substrates were influenced by the density of the pyramids as well as by the size and the rounded surface of the pyramids. To characterize and optimize the relevant texturing process in terms of mechanical stability and the fabrication yield, the mechanical properties of textured silicon substrates were investigated to optimize the size and morphology of random pyramids. Several types of silicon substrates were studied, including the planar type, a textured surface with large and small pyramids, and a textured surface with rounded pyramids. The surface morphology and a cross-section of the as-textured and fractured silicon substrates were investigated by scanning electron microscopy.

L1210과 HL60 암세포에 대한 야생식물의 세포독성 검색

이준성,민병선,배기환,Lee, Jun-Sung,Min, Byung-Sun,Bae, Ki-Hwan 한국생약학회 1996 생약학회지 Vol.27 No.3

For the search of anticancer compounds from natural products, 43 plants were extracted with benzene and methanol, separately, and the extracts were screened for the cytotoxicity against L1210 and HL60 cancer cell lines. From the results, 22 samples in benzene extracts showed cytotoxicity against L1210 cells and 23 samples against HL60 cells, respectively. However, any methanol extracts did not exhibit cytotoxicity against two cancer cell lines, it suggested that cytotoxic compounds seemed to have low polarity. $ED_{50}$ values less than $5\;{\mu}g/ml$ were observed in 14 and 9 samples in benzene extracts against L1210 and HL60 cancer cells, respectively.

니켈 무전해 도금된 탄소섬유 및 나노 입자를 활용한 초소수성/전기열 복합재

이준성(Jun-Sung Lee),황반토(Van-Tho Hoang),남영우(Young-Woo Nam) 한국항공우주학회 2021 한국항공우주학회 학술발표회 논문집 Vol.2021 No.11

고효율 전류모드 승압형 DC-DC 컨버터용 집적회로의 설계

이준성(Jun-sung Lee) 大韓電子工學會 2010 電子工學會論文誌 IE (Industry electronics) Vol.47 No.2

본 논문에서는 PWM을 활용한 전류모드 고효율 PWM DC-DC 전원변환 집적회로(Integrated Circuit)를 설계하였다. IC에 인가할 수 있는 최대 전압은 40[V]이며 입력 전압이 DC 2.8[V]~330[V]일 때 출력 전압을 이 보다 높은 전압으로 바꿀 수 있는 한편 외부 저항비나 트랜스의 권선비를 조정하여 원하는 DC 전압을 만들어 낼 수 있다. 출력전압의 3[%] 오차를 유지하면서 3[A] 이상의 전류를 부하에 공급할 수 있도록 구현하였다. 제작공정은 0.6[㎛], 2P_2M CMOS 공정을 사용하였다. 전원전압이 3.6[V]일 때 대기상태에서 소비전력은 1[㎽]이하이고 최대 전력변환 효율은 약 86[%]이다. 칩 사이즈는 2100*2000[㎛2]이며, 칩을 소형패키지에 내장하여 조립하였기 때문에 휴대형기기나 소형 전자기기에 적용이 편리하게 되어 있다. This paper describes a current mode PWM DC-DC converter IC for battery charger and supply power converter for portable electronic devices. The maximum supply voltage of IC is 40[V] and 2.8[V]~330[V] DC input power is converted to higher or programmed DC voltage according to external resistor ratio or wire winding ratio of transformer. The maximum supply output current is 3[A] over and voltage error of output node is within 3[%]. The whole circuit needed current mode PWM DC-DC converter circuit is designed. The package dimensions and number of external parts are minimized in order to get a smaller hardware size. The power consumption is smaller then l[㎽] at stand by period with supply voltage of 3.6[V] and maximum energy conversion efficiency is about 86[%]. This device has been designed in a 0.6[㎛] double poly, double metal 40[V] CMOS process and whole chip size is 2100*2000 [㎛2].

D-급 디지털 오디오 증폭기와 과전류 보호회로의 설계 및 제작

이준성 ( Jun-sung Lee ) 한국고등직업교육학회 2004 한국고등직업교육학회논문집 Vol.5 No.1

This paper presents a monolithic integrated circuit of the over current protection(OCP)circuit for the Class-D audio amplifier. The output voltage drop is increased as the output current is increased because of the Rdson at the output transistor. The OCP circuit shuts down the output transistor when the output current exceeds twice of the maximum current. The OCP circuit, consisted of the comparator and the level shift, generates a high pulse in case that the output voltage drop is greater than the reference voltage of the comparator. In order to check the operation of the OCP circuit for the Class-D amplifier that has a driving power capability of 30[W], a simulation, layout design and fabrication is performed. After testing the fabricated circuit, it is confirmed that the Class-D amplifier circuit has a driving current capability of 3.5[A] and the OCP circuit works at 7.3[A] to protect the over-current. This circuit is designed by a 0.65[㎛]@5[V], 2[㎛]@40[V] bCDMOS technology and the total size of the die is 2500[㎛]×4200[㎛], with a 1000[㎛]×160[㎛] sized OCP circuit in it.

초음파 거리 측정회로용 프론트-엔드 IC의 설계

이준성(Jun-sung Lee) 대한전자공학회 2010 電子工學會論文誌 IE (Industry electronics) Vol.47 No.4

초음파신호를 이용하여 두 물체 사이의 거리를 측정할 수 있도록 초음파신호를 발생시키고 이를 수신하여 증폭하는 프론트-앤드 IC를 설계하였다. 40[㎑]~300[㎑]의 초음파 신호를 발생시켜서 피에조진동자를 통해 간헐적으로 송신하는 회로와 피에조 수신기에서 받은 미세한 반사 신호를 증폭하여 노이즈를 제거한 후 처음 송신된 신호와의 시간 차이를 펄스폭으로 출력하고 이를 이용하여 물체사이의 거리를 계산할 수 있는 기능을 내장하였다. 본 설계에서는 두 가지 기술을 적용하여 기능을 개선하였다. 첫째, 주파수 자동조정(SFC) 회로이다. OTA회로의 gm을 가변시켜 초음파 신호발생기의 출력주파수와 수신단의 밴드패스필터의 중심주파수가 서로 연동되도록 조정해 줌으로써 신호 복원을 용이하게 하였다. 둘째, 가변 이득 조절회로(VGC)이다. 이 회로는 두 물체사이의 거리에 상관없이 수신되는 신호의 진폭이 일정하도록 동작하는 기능을 한다. 또한, 출력레벨변환회로를 적용하여 송신신호의 진폭을 40[V]로 상승시켜 측정거리를 늘리는 시도를 하였다. 시뮬레이션을 위한 공정은 0.6[um]급, 40[V] CMOS 공정을 사용하였다. 전원전압 5[V], 소비전력은 약 12[㎽]정도이다. 회로의 규모가 최소화 되어 있고 외부소자 수를 줄였기 때문에 휴대형기기에 편리하게 사용할 수 있게 하였다. This paper describes a ultrasonic signal processing front-end IC for distance range meter and body detector. The burst shaped ultrasonic signal is generated by a self oscillator and its frequency range is about 40[㎑]~300[㎑]. The generated ultrasonic signal transmit through piezo resonator. The another piezo device transduce from received ultrasonic signal to electrical signals. This front-end IC contained low noise amplifier, band pass filter, busrt detector and time pulse generator and so on. This IC has two type of new idea for improve function and performance, which are self frequency control (SFC) and Variable Gain Control amplifier (VGC) scheme. The dimensions and number of external parts are minimized in order to get a smaller hardware size. This device has been fabricated in a 0.6[um] double poly, double metal 40[V] High Voltage CMOS process.

동북공정 종료 후 중국학계의 고구려 ‘대외관계사’ 연구 동향

이준성(Lee Jun-Sung) 한국고대학회 2017 先史와 古代 Vol.- No.53

동북공정이 종료된 2007년 이후 중국 학계에서 제출된 고구려 ‘대외관계사’ 논문은 동북공정 기간 정리된 ‘번속체제’의 영향을 크게 받았다는 특징을 지닌다. 대다수의 연구는 고구려와 중국 왕조의 관계가 ‘일국관계’임을 전제로 진행된 것이다. 반면 조공책봉제도의 성격과 관련 하여 그것을 고대 동아시아의 지역질서로 파악하는 연구들도 일부 있다. 그러나 이 경우에도 동아시아 세계의 성립과 발전을 오직 漢化라는 입장으로만 설명하여, 중국 중심사관에서 벗어나지 못하는 모습을 보이고 있었다. 한편, 돌궐이나 유연 등 북방민족과의 관계와 관련된 연구는 여전히 미흡하다는 점 역시 중국 학계의 인식이 여전히 중원왕조 중심의 관계 해명에 치중되어 있음을 방증한다. 이는 동아시아 세계가 중국 중심의 일원적 국제질서가 아닌 복수의 국제질서로 구성되어 있었다는 점을 시야에 넣지 못한 한계로 생각할 수 있다. The studies on Goguryeo’s ‘History of Foreign Relations’ submitted to the academic circles of China after 2007 when the Northeast Project of China ended show the characteristic that they are all greatly influenced by the ‘Fanshu Theory’ which was established during the Northeast Project period. Most studies were conducted based on the premise that the relations between Goguryeo and Chinese Dynasties were ‘One Country Relations.’ On the other hand, there are studies that see the characteristic of the Tributary Appointment System as the regional order of the ancient East Asia. However, such studies also explained the formation and development the East Asian world only based on the sinicization, failing to move away from the Sinocentric historical view. The fact that there are still not many studies about the relationship with northern races such as Gokturks or Rouran Khaganate also circumstantially evidence that the Chinese academic circles still focus on elucidating the relations centering on the Central Plains Dynasties. This can be attributed to the limit that Chinese academic circles have due to the exclusion of the idea that the East Asian world was under the influence of multiple international order not under the unitary international order centering on China in their vision.