고품질 4H-SiC 단결정 성장을 위한 다공성 흑연 판의 역할

이희준,이희태,신희원,박미선,장연숙,이원재,여임규,은태희,김장열,전명철,이시현,김정곤,Lee, Hee-Jun,Lee, Hee-Tae,Shin, Hee-Won,Park, Mi-Seon,Jang, Yeon-Suk,Lee, Won-Jae,Yeo, Im-Gyu,Eun, Tai-Hee,Kim, Jang-Yul,Chun, Myoung-Chul,Lee, Si-Hyun 한국결정성장학회 2015 한국결정성장학회지 Vol.25 No.2

본 연구에서는 PVT법으로 4H-SiC 단결정 성장 시 다공성 흑연판을 사용하여 Si/C 비율이나 온도구배, 물질전달의 향상시킴으로써 고품질의 SiC 단결정 기판 제작을 목적으로 연구를 진행하였다. 연구에 사용된 SiC 소스 물질은 흑연 도가니에 넣어 흑연 단열재로 쌓인 구조로 실험을 하였다. 성장온도는 $2100{\sim}2300^{\circ}C$, 그리고 성장압력은 10~30 Torr의 압력으로 아르곤과 질소 분위기에서 성장시켰다. 종자정은 2인치의 $4^{\circ}$ off-axis 4H-SiC의 C면 (000-1)을 사용하였고 다공성 흑연판은 SiC 소스 물질 위에 삽입하였다. 4H-SiC 결정다형 안정화를 위한 C-rich 조건이나 균일한 온도구배를 만들어주기 위해 다공성 흑연판을 삽입하여 실험을 진행하였다. 일반적인 도가니의 경우, 성장된 wafer에서 6H-, 15R-SiC와 같은 다양한 결정다형이 관찰된 반면에 다공성 흑연판을 삽입한 도가니에서는 4H-SiC만 관찰되었다. 또한 다공성 흑연판을 삽입한 도가니에서 성장된 결정에서 MP나 EP의 낮은 결함밀도를 보였으며 결정성 또한 향상된 것을 학인하였다. The present research is focused on the effect of porous graphite what is influenced on the 4H-SiC crystal growth by PVT method. We expect that it produces more C-rich and a change of temperature gradient for polytype stability of 4H-SiC crystal as adding the porous graphite in the growth cell. The SiC seeds and high purity SiC source materials were placed on opposite side in a sealed graphite crucible which was surrounded by graphite insulator. The growth temperature was around $2100{\sim}2300^{\circ}C$ and the growth pressure was 10~30 Torr of an argon pressure with 5~15 % nitrogen. 2 inch $4^{\circ}$ off-axis 4H-SiC with C-face (000-1) was used as a seed material. The porous graphite plate was inserted on SiC powder source to produce a more C-rich for polytype stability of 4H-SiC crystal and uniform radial temperature gradient. While in case of the conventional crucible, various polytypes such as 6H-, 15R-SiC were observed on SiC wafers, only 4H-SiC polytype was observed on SiC wafers prepared in porous graphite inserted crucible. The defect level such as MP and EP density of SiC crystal grown in the conventional crucible was observed to be higher than that of porous graphite inserted crucible. The better crystal quality of SiC grown using porous graphite plate was also confirmed by rocking curve measurement and Raman spectra analysis.

타목시펜 사용과 연관되어 빠르게 진행하는 다발성 자궁내막폴립 1예

이희준,김훈,구승엽,한원식,김석현,최영민,김정구,문신용,Lee, Hee-Jun,Kim, Hoon,Ku, Seung-Yup,Han, Won-Shik,Kim, Seok-Hyun,Choi, Young-Min,Kim, Jung-Gu,Moon, Shin-Yong 대한생식의학회 2010 Clinical and Experimental Reproductive Medicine Vol.37 No.2

The antiestrogen tamoxifen is currently the most commonly used adjuvant treatment of breast cancer with antiestrogenic effect on mammary tissue. However, it is also associated with endometrial abnormalities, including hyperplasia, polyps, carcinoma, mostly interpreted as evidence of estrogenic effect on the endometrium. Previously, tamoxifen-associated polyp in breast cancer has been reported in the literature. Most studies had a long follow-up period and tamoxifen-associated polyp developed more than 1 year after tamoxifen treatment. In this case, we report an unusual case of rapid growing and multiple endometrial polyps that were developed only after 3 months' tamoxifen treatment in a postmenopausal breast cancer patient who received quadrant mastectomy with a brief review of literature. 유방암의 치료는 수술, 항암치료 및 방사선 치료 등의 주 치료법이 있으며, 유방암 환자에서 주 치료 후 보조적 치료 수단으로 호르몬 치료가 사용된다. 이 호르몬 치료에는 타목시펜이 가장 보편적으로 사용되며, 타목시펜은 체내에서 항에스트로겐 효과를 보여 유방암 치료에 도움을 주며 유방암의 재발방지에도 효과가 있다고 알려져 있다. 그러나 타목시펜의 부작용 또한 여러 가지가 있으며 문헌에 보고된 것으로는 자궁내막폴립, 자궁내막증식증, 자궁내막암 등이 있다고 알려져 있다. 본원에서도 유방암으로 수술 치료를 시행 받은 후 보조적 치료로서 호르몬 제제인 타목시펜을 사용하여 왔으며 이러한 환자들은 모두 외과와 협진하여 산부인과 외래로 추적 관찰하고 있다. 최근에 본원산부인과 외래로 추적 관찰 중인 타목시펜 사용 환자 중에서, 호르몬 치료 시작 3개월 후의 단기간 내에 빠르게 진행하는 다발성의 자궁내막폴립의 1예가 발견되었으며, 이는 타목시펜의 부작용으로 발생한 것으로 사료된다. 이에 저자는 유방암 수술 후 보조적 치료로 타목시펜을 사용한 환자들 중 우연히 발견된 빠르게 진행하는 다발성의 자궁내막폴립의 1예를 문헌고찰과 함께 보고하는 바이다.

한국 개신교 교회건축의 평면형태 변천 연구 - '남녀유별' 관념과 회중석의 남녀 위치를 중심으로 -

이희준,윤인석,Lee, Hee-Jun,Yoon, In-Suk 한국건축역사학회 2005 건축역사연구 Vol.14 No.3

The plan type of Korean protestant church architecture underwent changes as following five stages according to the changes of the distinction between the sexes. First stage - At the beginning of missionary work in Korea, Koreans generally worshiped in missionary houses which were traditional Korean styles. The plan type of these houses was a simple '-' figure. At that time, men and women worshiped separately because of the idea of the distinction between the sexes. They either worshiped in different places at the same time or in the same place at the different time. Second stage - At this stage, men and women started to worship together in the same place. At the beginning of this stage, men sat in the front of the chapel on a rostrum, and women sat behind the men. The plan type of the chapel was a simple '-' or a rectangular figure. Later, they sat separately on the right and left side. There are the visual interceptions which were set up between them. As the number of church members increased rapidly, a new type of church architecture appeared. It was a 'ㄱ' figure. At that time the entrances were separated by the sexes. Third stage - At this stage, the visual interceptions disappeared as the idea of the distinction between the sexes became weak. As new churches had been constructed by the plan type of rectangular figure, the visual interceptions weren't set up anymore. Fourth stage - At this stage, the separated entrances were unified as one. But the arrangement of their seats didn't change because of the old idea of the distinction between the sexes. Fifth stage - In the final stage, the plan type of the church architecture was not determined by the idea of the distinction between the sexes but social, economical, technological facts and the influence of the foreign architecture. At this stage, new and various kinds of the plan type appeared such as the fan, round, squared, or oval figure as well as the rectangular figure. Men and women were not classified anymore. They started to sit and worship together in the same place. Also, when men and women sat separately from side to side because of the Idea of the distinction between the sexes, men sat on the right and women sat on the left side of rostrum. It didn't applied Confucian ideas but the idea of protestant church; protestant churches have the idea that the right side is more important but it does not in Confucianism.

만 입구에서 부유퇴적물 거동과 플럭스: 한반도 서해 남부 함평만의 여름철 특성

이희준,박은순,이연규,정갑식,추용식,Lee, Hee-Jun,Park, Eun-Sun,Lee, Yeon-Gyu,Jeong, Kap-Sik,Chu, Yong-Shik 한국해양학회 2000 바다 Vol.5 No.2

반폐쇄형의 함평만 입구를 가로지르는 두 개의 정점(H1, H2)에서 1999년 8월 12-13일 대조기에 각각 한 조석주기동안 물리적 특성과 부유퇴적물의 농도변화에 대한 정선관측을 실시하였다. 수온과 염분의 조석변화는 각각 26.0-27.9$^{\circ}C$, 30.9-31.5 범위에서 창조시 저온과 고염분의 외해수 그리고 낙조시 고온과 저염분의 연안수 특성을 보이며, 복사열이 강한 여름철임에도 불구하고 강한 조류의 혼합작용으로 인해 수괴의 수직적 혼합이 잘 이루어지고 있다. 부유퇴적물의 농도는 표층에서 낮고 저층으로 향하면서 높아지며 수층별로 뚜렷한 차이를 보이고 있다. 불량한 분급도를 보이는 부유퇴적물은 대부분 극세립- 세립실트(>40%)로 구성되어 있는 가운데, 점토 크기 이하(<4 ${\mu}m$)의 세립자들은 에너지가 약한 정조시에 상호간의 결합을 통해 입자 덩어리를 형성하고 있다. 조석별 평균유속의 세기는 남서쪽 정점 H1의 경우 낙조류가 창조류에 비해 수층에 따라 23-59${\%}$ 우세한 반면, 정점 H2에서는 오히려 창조류가낙조류에 비해 27-37${\%}$ 우세한 비대칭성을 보이고 있다. 이에 따른 각 정점에서 계산된 잔여유속은 정점 H1에서 아주 큰 값(-10${\sim}$-20 cm $s^{-1}$)으로 외해쪽으로 향하고 있는 반면, 정점 H2에서는 내만쪽으로 향하는 미약한 흐름(<5 cm $s^{-1}$)이 존재한다. 한편, 부유퇴적물의 농도변화는 남서쪽(H1)에서 낙조시에 비해 창조류를 따라 외해로부터 유입되는 양이 많고, 정점 H2에서는 창조시에 비해 낙조류를 따라 외해로 유출되는 양이 훨씬 높게 나타나고 있다. 잔여유속과 부유퇴적물의 농도를 고려한 부유퇴적물의 순이동률($f_{s}$)은 모든 정점에서 수층에 따라 -1.7 ${\sim}$-15.6${\times}$$10^{-3}$ kg $m^{-2}$ $s^{-1}$ 속도로 일관되게 외해쪽으로 향하고 있으며, 북동쪽에서 보다 빠른 이동률을 보이고 있다. 부유퇴적물의 순이동량($\c{Q}_{s}$)은 정점 H1과 H2에서 각각 0.37${\times}$$10^{3}$, 0.21${\times}$$10^{3}$ kg $m^{-1}$의 양이 여름철 대조기 한 조석주기동안에 외해로 빠져나가고 있는 것으로 나타났다. 함평만 입구에서 여름철임에도 불구하고 부유퇴적물이 외해쪽으로 이동되고 있는 것은 내만에 발달되어 있는 조간대의 침식을 의미하는 것으로서, 지금까지 서해안 조간대에서 보고되고 있는 일반적인 여름철 퇴적현상과는 상이한 결과를 나타내고 있다. Anchored measurements (12.5 hr) of suspended sediment concentration and other hydrodynamic parameters were carried out at two stations located at the entrance to Hampyung Bay in summer (August 1999). Tidal variations in water temperature and salinity were in the range of 26.0-27.9$^{\circ}C$ and 30.9-31.5, respectively, indicating exchange offshore and offshore water mass. Active tidal mixing processes at the entrance appear to destroy the otherwise vertical stratification in temperature and salinity in spite of strong solar heating in summer. On the contrary, suspended sediment concentrations show a marked stratification with increasing concentrations toward bottom layer. Clastic particles in suspended sediments consist mostly of very fine to fine silt (4-16 ${\mu}$m) with a poorly-sorted value of 14.7-25.9 ${\mu}$m. However, at slack time with less turbulent energy, flocs larger than 40 ${\mu}$m are formed by cohesion and inter-collision of particles, resulting in a higher settling velocity. Strong ebb-dominated and weak flood dominated tidal currents, in the southwestern and the northeastern part, respectively, result in a seaward residual flow of -10${\sim}$-20 cm $s^{-1}$ at station H1 and a bayward residual flow less than 5.0 cm $s^{-1}$ at station H2. However, mean concentration of suspended sediments at station H1 is higher at flood (95.0-144.1 mg $1^{-1}$) than in ebb (75.8-120.9 mg $1^{-1}$). On the contrary, at the station H2, the trend is reversed with higher concentration at the ebb (84.7-158.4 mg $1^{-1}$) than that at the flood (53.0-107.9 mg $1^{-1}$). As a result, seaward net suspended sediment fluxes ($f_{s}$) are calculated to be -1.7 ${\sim}$-$15.610^{3}$ kg $m^{-2}$ $s^{-1}$ through the whole water column. However, the stations H1 and H2 show definitely different values of the flux with higher ones in the former than in the latter. Alternatively, depth-integrated net suspended sediment loads ($\c{Q}_{s}$) for one tidal cycle are also toward the offshore with ranges of 0.37${\times}$$10^{3}$ kg $m^{-1}$ and 0.21${\times}$$10^{3}$ kg $m^{-1}$, at station H1 and H2, respectively. This seaward transport of suspended sediment in summer suggests that summer-time erosion in the Hampyung muddy tidal flats is a rather exceptional phenomenon compared to the general deposition reported for many other tidal flats on the west coast of Korea.

고승압 듀얼 컨버터와 단상 하프 브릿지 인버터를 적용한 새로운 PCS

이희준(Hee-Jun Lee),신수철(Soo-Choel Shin),현승욱(Seung-Wook Hyun),정용채(Yong-Chae Jung),원충연(Chung-Yuen Won) 전력전자학회 2013 전력전자학회 논문지 Vol.18 No.6

우리나라 원자력안전 행정체제의 개선방안

이희준(Hee Jun Lee),임봉수(Bong Su Lim) 대전대학교 환경문제연구소 2015 환경문제연구소 논문집 Vol.19 No.-

This study was carried out to suggest a improvement plan for nuclear administration system in korea by comparing our country with other leading countries for nuclear power policy, current state and plans. It is suggested that NSSC, directly responsible to the prime minster should be upgraded to the president, the independence of NSSC will be maintained. A region safety committee directly responsible to the local government should be established, forge the dualistic regulation framework for mutual help and check, and consolidate the supervision of management for local nuclear power plant. NSSC is in charge of the engineered safety and protection of facilities, disaster protection etc., regional safety committee plays a special role in the safety measures for inhabitants and environmental monitoring.

폴리머-시멘트 프린팅 콘크리트의 적층성 연구

이희준(Lee, Hee Jun),김진효(Kim, Jin Hyo),강원호(Kang, Won Ho),연규석(Yeon, Kyu-Seok) 한국콘크리트학회 2017 한국콘크리트학회 학술대회 논문집 Vol.29 No.2

한국 개신교 교회건축 예배공간의 평면유형 분류 및 변천 특성 연구

이희준(Lee Hee-Jun),김정일(Kim Jeong-Il),윤인석(Yoon In-Suk) 대한건축학회 2009 대한건축학회논문집 Vol.25 No.5

This study classified the plan type of Korean Protestant churches by analyzing church architectures which have been reported in Architectural magazines since 1960. Also, the study analyzed relationship of 'the year of construction -denominationarrangements of pews. From this study, we reached into conclusions as follow: First of all, plan types can be divided into classes: a quadrangle, a fan shape, a circle, an octagon, a symbol type, and an irregular type. Also, each class can be divided into a various of shapes according to its type. Second, a plan type of a quadrangle type showed the highest distribution rate, but as times went by, the rate has been decreasing gradually. The distribution rate of a horizontal rectangle, a irregular quadrangle, a acute fan shape, a circle, an octagon, a oval type has been increasing. Third, a plan type of a rectangle type in most denominations was most preferable one. Also, the distribution rate of preference was the highest in the Holiness Church, and the rate tends to decrease from the Baptist Church to the Methodist Church, Full Gospel Church, Presbyterian Church, and independent churches. Finally, specific seat arrangements of church attendants vary according to each plan type. However, seat arrangements making the central axis worship were shown in a rectangle type, such as types of church procession ceremony.

산전초음파로 진단된 태아 일측성 폐무발생

이희준 ( Hee Jun Lee ),김선영 ( Sun Young Kim ),박정우 ( Jeong Woo Park ),김우오 ( Woo Oh Kim ),박찬욱 ( Chan Wook Park ),박중신 ( Joong Shin Park ),전종관 ( Jong Kwan Jun ),신희철 ( Hee Chul Syn ) 대한산부인과학회 2011 Obstetrics & Gynecology Science Vol.54 No.12

Unilateral pulmonary agenesis is a very rare developmental malformation that is often associated with other anomalies. The prognosis of pulmonary agenesis varies from stillbirth, to neonatal death, to survival without any symptoms depending on the presence of associated congenital malformations. Therefore, it is very important to perform a prenatal diagnosis of unilateral pulmonary agenesis. We describe a case of unilateral pulmonary agenesis diagnosed in the second trimester by transabdominal ultrasound.

진해만의 부유퇴적물 기원과 이동

이희준(Hee Jun Lee),조형래(Hyung Rae Jo),추용식(Yong Sik Chu),박장준(Jang Jun Bahk),왕야핑(Ya Ping Wang) 한국해양환경·에너지학회 2002 한국해양환경·에너지학회 학술대회논문집 Vol.2002 No.-