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.

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.

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

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

플랫 판넬표시장치용 DC-DC 컨버터 집적회로의 설계

이준성(Jun-sung Lee) 대한전자공학회 2013 전자공학회논문지 Vol.50 No.10

본 논문은 플랫판넬 디스플레이 장치에 사용할 DC-DC 변환기의 설계에 관한 것이다. 6~14[V]의 단일 DC 전원전압으로부터 플랫 판넬 백바이어스용 -5[V] DC 전압 발생회로(Negative DC Voltage Generator)와 승압된 15[V], 23[V] DC 전압 발생회로, 그리고 강압된 3.3[V] DC를 얻기 위한 회로를 설계하였다. 또한 기준 전압원으로 사용하기 위한 밴드갭 회로와 발진기, 레벨변환기 회로, 고온보호 회로 등을 설계하였다. 제작공정은 부(-)전압으로 동작하는 회로와 기타 회로를 분리하기 위해서 트리플-웰(Triple-Well)구조가 적용된 공정 내압 30[V], 최소선폭 0.35[㎛], 2P_2M CMOS 공정을 사용하였다. 설계된 모든 회로는 시뮬레이션으로 검증하여 동작을 확인하였으며 원 칩으로 제작하여 플랫판넬 디스플레이 장치에 응용할 수 있도록 기능을 확보하였다. This paper describes a DC-DC converter IC for Flat Panel Displays. In case of operate LCD devices various type of DC supply voltage is needed. This device can convert DC voltage from 6~14[V] single supply to -5[V], 15[V], 23[V], and 3.3[V] DC supplies. In order to meet current and voltage specification considered different type of DC-DC converter circuits. In this work a negative charge pump DC-DC converter(-5V), a positive charge pump DC-DC converter(15V), a switching Type Boost DC-DC converter(23V) and a buck DC-DC converter(3.3V). And a oscillator, a thermal shut down circuit, level shift circuits, a bandgap reference circuits are designed. This device has been designed in a 0.35[㎛] triple-well, double poly, double metal 30[V] CMOS process. The designed circuit is simulated and this one chip product could be applicable for flat panel displays.

디지털카메라의 자동초점제어를 위한 피에조 구동회로의 설계

이준성(Lee, Jun-Sung) 한국전기전자학회 2010 전기전자학회논문지 Vol.14 No.3

피에조소자를 구동하여 자동카메라의 초점을 자동으로 제어하는 시스템에서 피에조를 구동하는 집적회로를 설계하였다. 가공된 피에조에 변위를 만들기 위해서는 고전압 DC가 필요하다. 휴대형기기에서 사용하는 3[V]~4.2[V]정도의 낮은 전원전압을 약 80[V]로 승압하여 피에조 구동전압으로 제공하는 한편 입력되는 1[Vp-p]의 제어신호를 -20[V]에서 +80[V]까지 조절되도록 설계하였다. 또한 IC 외부에 적용되는 소자가 최소가 되도록 하여 시스템의 전체 크기를 줄일 수 있도록 하였다. 제어용 프로세서로 IIC(Inter-IC) 인터페이스를 적용하기 위하여 구동회로 내부에 IIC 인터페이스 디지털 로직을 내장하였는데, 이는 제품의 검증, 양산시 양품판정을 쉽게 해주는 장점이 있다. 제작공정은 AMIS 사의 I2T100 2P_3M 공정을 사용하였는데 0.6[um], 100[V]급 BCD공정이며, 6INCH 웨이퍼를 사용하였다. 전원전압 3.6[V], 소비전력은 약 40[mW]정도이다. 칩 사이즈는 1600*1500 [um²]이며, 칩을 소형패키지에 내장하여 조립하였기 때문에 휴대형기기에 적용이 편리하게 되어있다. This paper describes a auto focus piezo actuator driver IC for portable digital camera. The 80[V] DC voltage is generated by a DC-DC converter and supplied to power of piezo moving control circuit. The voltage of piezo actuator needs range -20[V] to 80[V] proportional to 1[Vp-p] input control voltages. The dimensions and number of external parts are minimized in order to get a smaller hardware size. IIC(Inter-IC) interface logic is designed for data interface and it makes debugging easy, test for mass productions. The power consumption is around 40[mW] with supply voltage of 3.6[V]. This device has been fabricated in a 0.6[um] double poly, triple metal 100[V] BCD MOS process and whole chip size is 1600*1500 [um²].

가변주파수 스위칭 DC-DC 컨버터용 집적회로를 위한 기능 회로 설계

이준성(Jun-sung Lee) 대한전자공학회 2016 전자공학회논문지 Vol.53 No.1

본 논문은 가변 스위칭 주파수 PFM을 이용한 DC-DC 변환기의 집적회로 개발 시, 적용 가능한 주요 기능 블록의 설계에 관한 것이다. DC전압 변환 시 부하에 공급되는 전류가 작거나 출력전압이 설정값 근처에 도달했을 때 PFM 모드로 동작시켜 전력변환 효율을 높일 수 있다. PFM DC-DC 변환기 구현에 필요한 PFM 신호 발생회로, PFM 주파수 제어기, 출력전압감지회로 그리고 과전류보호회로를 설계하였다. 설계를 위한 공정파라미터는 내압 12[V], 최소선폭 0.35[㎛], 2P_2M CMOS 공정을 사용하였다. This paper describes functional circuits of DC-DC converter IC incorporated with variable frequency PFM technique. In case of output voltage of DC-DC converter is reached setting value or output current is low then PFM switching frequency is slow down. In this work a PFM signal generator, a PFM Frequency Control Circuit, an output voltage detector and an over current protection circuits are designed. This device has been designed at a 0.35[㎛], double poly, double metal 12[V] CMOS process.

동원과 연화, 통제와 교섭 : 1~2세기 동아시아 국제관계와 전쟁

이준성(Lee, Jun-sung) 한국고대사학회 2023 韓國古代史硏究 Vol.- No.112

본고는 漢과 匈奴의 쇠퇴라는 변화 속에서 1~2세기 동아시아 국제관계와 전쟁에 대해 동원과 연화, 통제와 교섭이라는 키워드를 통해 살펴보았다. 구체적으로는 동아시아에서 국제관계가 변화하는 계기를 찾아 그 양상을 추적하고, 갈등이 고조되며 전쟁으로 이어지는 과정과 그 갈등이 해소되는 과정, 그리고 이에 연동하여 어떻게 정책이 수립되고 적용되는지를 논의하였다. 1세기 초 전한의 멸망 후 신 왕망은 강경한 대외정책은 국제사회의 긴장과 충돌을 유발하였다. 이에 더하여 흉노를 정벌하기 위해 고구려와 오환 등 주변세력의 병력을 ‘동원’하였는데, ‘동원’된 세력들은 이에 따르거나 혹은 出塞하여 도망하는 방식으로 대응했다. 또한 주변 세력과 ‘연화’하기도 하였다. ‘연화’에 따라 가중된 어려움을 타개하기 위해 후한은 유화책을 활용하였다. 이는 당시 연화하고 있던 주변 세력 사이에 균열을 유도하고, 상호 견제 및 경쟁하는 상태로 만들기 위한 의도를 담은 것이었다. 2세기 이후 주변 세력은 후한 군현에 내속하면서 일종의 교섭을 진행한다. 그중 고구려는 주변 세력을 본격적으로 전쟁에 ‘동원’하는 모습을 보이기도 하는데, 이는 기존에 중국 주변세력들이 ‘연화’하고 있던 것과는 질적으로 다른 변화라 할 수 있다. 아울러 2세기 중반경 단석괴를 중심으로 선비가 부상하여 후한 조정의 통제 범위를 완전히 벗어나면서 제국의 위기가 찾아온다. 189년 요동지역에서 公孫度가 ‘자립’을 선언하고, 오환과 고구려의 독자적 움직임 역시 뚜렷해지면서, 국제질서는 더욱 동요하였고 동아시아는 다시 분열의 시기로 접어들었다. This study examines international relations and warfare in East Asia during the first and second centuries. It identifies the triggers for the change in international relations in East Asia, traces the patterns, and discusses the processes by which conflicts escalate and lead to war, how they are resolved, and how policies are formulated and applied in conjunction with them. After the fall of former Han Dynasty(前漢) in the early first century, the new king, Wang Mang, took a hardline foreign policy, which led to tensions and conflicts in the international community. In addition, he ‘mobilized’ the troops of neighboring powers such as Goguryeo(高句麗) and Wuhuan(烏桓) to subdue them, and the ‘mobilized’ powers responded by either complying or fleeing. To overcome the difficulties created by appeasement, later Han Dynasty(後漢) utilized appeasement. The intention was to induce a rift between the neighboring powers that were allied at the time and put them in a state of mutual checks and balances and competition. From the second century onward, the neighboring powers would engage in some form of negotiation while remaining subordinate to later Han Dynasty. Among them, Goguryeo appears to have ‘mobilized’ the peripheral powers to war in earnest, which is a qualitatively different change from the previous ‘alliance’ of the Chinese peripheral powers. In addition, around the middle of the 2nd century, the imperial crisis came as the Xianbei(鮮卑) was completely out of the control of the generous adjustment centered on the Danseokgyo(檀石槐). In 189, Gongsondo(公孫度) declared ‘self-reliance’ in the Liaodong region(遼東), and the independent movements of Wuhuan and Goguryeo became apparent, further agitating the international order, and East Asia entered a period of division again.

Low Dropout Voltage Regulator용 직접회로의 설계 및 제작

이준성 ( Jun-sung Lee ) 한국고등직업교육학회 2001 한국고등직업교육학회논문집 Vol.2 No.4

This paper presents a monolithic integrated circuit designed for a low dropout(LDO) voltage and high accuracy voltage regulator. It consists of bandgap reference, TSD(Thermal Shut Down), TCC(Temperature Compensation Circuit), OVP(Over Voltage Protection), OCP(Over Current Protection), bias and output current driving circuits. In order to obtain accurate regulation voltages, metal fusing technique is adopted thus the accuracy of the reference voltage is Vout±1[%]. The maximum current driving capability of this IC is 1.5[A] at 1.2[V] Dropout voltage and a line regulation of a regulated output voltage is measured less than 0.02[%]. The stand-by current is 5[mA]. This circuit has been designed by a 2[㎛], 20[V] bipolar technology and the die area is 2.1 [㎟].