Self-seed layer를 이용하여 증착한 SBT박막의 특성

김형섭,황동현,윤지언,손영국,Kim, Hyung-Sub,Hwang, Dong-Hyun,Yoon, Ji-Un,Son, Young-Gook 한국진공학회 2007 Applied Science and Convergence Technology Vol.16 No.3

[ $Pt/SBT/Seed/Pt/Ti/SiO_2/Si$ ]의 구조로 $SBT(SrBi_2Ta_2O_9)$ 박막을 Self-seed layer를 사용하여 R.F. Magnetron sputter를 이용하여 증착을 하였다. Self-seed layer는 기판온도 RT(room temperature)와 $600^{\circ}C$에서 두께 30 nm으로 증착하였다. Self-seed layer의 결정화 온도를 알아보기 위해 열처리온도를 변화시켰고 이를 XRD를 통하여 결정화 유무를 확인하였다. Self-seed layer 위에 증착한 SBT를 XRD와 전기적 측정을 통해 특성을 관찰하였다. Thin films of $SBT(SrBi_2Ta_2O_9)$ having $Pt/SBT/Seed/Pt/Ti/SiO_2/Si$ structure were fabricated using self-seed layer method by R.F. Magnetron sputter. Self-seed layers were deposited at room temperature and $600^{\circ}C$, which had 30 nm thickness. To investigate crystallization of self-seed layer we characterized by XRD after various heat treatment. And we characterized the crystallinity and electrical properties of SBT on self-seed layer after various heat treatment.

염화수은의 신장독성 지표 반응성 비교연구

김형섭 ( Hyung Sub Kim ),김용순 ( Yong Soon Kim ),임채형 ( Chae Hyung Lim ),곽승준 ( Seung Jun Kwack ),조영래 ( Young Rae Cho ),강미선 ( Mi Sun Kang ),오재호 ( Jae Ho Oh ),조완섭 ( Wan Seob Cho ),한범석 ( Bum Seok Han ),김승희 ( S 한국동물실험대체법학회 2007 동물실험대체법학회지 Vol.1 No.2

To compare the responsiveness of nephrotoxicity parameters, mercuric chloride(HgCl2) was administered intraperitoneally at the doses of 0.2, 0.6 and 1.0 mg / kg for different exposure periods(1, 3 and 7 days) using F344N rats. We compared several parameters resulted from animal study(body weight change, organ weight), clinical pathological(serum and urine chemistry), histopathological study and toxicogenomic study. Animal body weight significantly decreased and kidney weight(relative) increased in a dose-dependent manner. Serum chemistry analysis showed that BUN and creatinine were relatively one of nephrotoxicity biomarkers against HgCl2 and serum chemistry analysis was more sensitive than urine analysis. In the histopathological study, dose and time-dependency was clearly observed. Cellular swelling was observed in the low dose(0.2 mg / kg) group(1 day treatment) and focal inflammation including cellular swelling was observed in the high dose group. In the DNA microarray analysis, gene expression profiles were analysed in the 1-day and 3-days treatment group. Taken together, the responsiveness of individual parameter(body weight change, organ weight, clinical pathology, histopathology and DNA microarray) was different. This study suggests that these considerations should be involved in the analysis of toxicity study data as well as toxicogenomic study could provide a useful information to reduce the number of experimental animals used in the repeated toxicity study.

연구논문 : 염화수은의 신장독성 지표 반응성 비교연구

김형섭 ( Hyung Sub Kim ),김용순 ( Yong Soon Kim ),임채형 ( Chae Hyung Lim ),곽승준 ( Seung Jun Kwack ),조영래 ( Young Rae Cho ),강미선 ( Mi Sun Kang ),오재호 ( Jae Ho Oh ),조완섭 ( Wan Seob Cho ),한범석 ( Bum Seok Han ),김승희 ( S 한국동물실험대체법학회 2007 동물실험대체법학회지 Vol.1 No.2

To compare the responsiveness of nephrotoxicity parameters, mercuric chloride(HgCl2) was administered intraperitoneally at the doses of 0.2, 0.6 and 1.0 mg / kg for different exposure periods(1, 3 and 7 days) using F344N rats. We compared several parameters resulted from animal study(body weight change, organ weight), clinical pathological(serum and urine chemistry), histopathological study and toxicogenomic study. Animal body weight significantly decreased and kidney weight(relative) increased in a dose-dependent manner. Serum chemistry analysis showed that BUN and creatinine were relatively one of nephrotoxicity biomarkers against HgCl2 and serum chemistry analysis was more sensitive than urine analysis. In the histopathological study, dose and time-dependency was clearly observed. Cellular swelling was observed in the low dose(0.2 mg / kg) group(1 day treatment) and focal inflammation including cellular swelling was observed in the high dose group. In the DNA microarray analysis, gene expression profiles were analysed in the 1-day and 3-days treatment group. Taken together, the responsiveness of individual parameter(body weight change, organ weight, clinical pathology, histopathology and DNA microarray) was different. This study suggests that these considerations should be involved in the analysis of toxicity study data as well as toxicogenomic study could provide a useful information to reduce the number of experimental animals used in the repeated toxicity study.

LTE 기지국 제어평면 기능 구현방안에 관한 연구

김형섭(Hyung-sub Kim),나지현(Jeehyeon Na),피준일(Junil Pi) 한국통신학회 2017 한국통신학회 학술대회논문집 Vol.2017 No.1

리어가이더 시작각 변화가 횡류홴 성능에 미치는 영향

김형섭(Hyung-Sub Kim),김동원(Dong-Won Kim),윤태석(Tae-Seok Yoon),박성관(Sung-Kwan Park),김윤제(Youn J. Kim) 대한기계학회 2004 대한기계학회 춘추학술대회 Vol.2004 No.4

A cross-flow fan relatively makes high dynamic pressure at low speed because a working fluid passes through an impeller blade twice and blades have a forward curved shape. Therefore, the performance of a cross-flow fan is influenced 25% by the impeller, 60% by the rearguider and the stabilizer, 15% by the heat exchanger. At the low flow rate, there exists a rapid pressure head reduction, a noise increase and an unsteady flow against a stabilizer and a rearguider. Moreover, it is difficult to analyze the reciprocal relations of the cross-flow fan because each parameter is independent. Numerical analyses are conducted with different starting angles of the rearguider. Two-dimensional, unsteady governing equations are solved, using FVM, PISO algorithm, sliding grid system and κ?ε standard turbulence model.

은어, Plecoglossus altivelis 種苗生産을 위한 먹이생물학적 연구

김형섭(Hyung Sub KIM),허성범(Sung Bum HUR) 한국수산과학회 양식분과 1994 韓國養殖學會誌 Vol.7 No.3

수중 근무자 선발에서 다면적 인성검사의 도입

김성우 ( Sung-woo Kim ),오경재 ( Gyung-jae Oh ),김민선 ( Min-sun Kim ),김형섭 ( Hyung-sub Kim ),김형기 ( Hyung-ki Kim ),차수강 ( Su-gang Cha ),김희덕 ( Hee-duck Kim ),정형배 ( Hyung-bae Chung ) 국군의무사령부 2000 대한군진의학학술지 Vol.31 No.1

구강보호장치의 재료적인 특성이 하악골 충격 시악골 및 두부에 미치는 영향에 관한 유한요소분석

강남현,김형섭,우이형,최대균,Kang, Nam-Hyun,Kim, Hyung-Sub,Woo, Yi-Hyung,Choi, Dae-Gyun 대한치과보철학회 2008 대한치과보철학회지 Vol.46 No.4

연구목적: 본 연구의 목적은 하악골 충격 시 구강보호장치의 재료적 성질에 따른 악골과 두부에 미치는 영향을 조사하는 것이다. 연구재료 및 방법: 경질과 연질의 서로 다른 성질을 가지는 구강보호장치를 두부외상이나 뇌질환 병력이 없고 정상교합과 자연치열을 가진 한국 성인 여성에게 제작하고, CT를 이용하여 악골과 두부의 3차원 유한요소모델을 제작하였다. 이 유한요소모델은 두개골, 뇌, 상악골, 하악골, 관절원판, 치아와 구강보호장치를 포함하며 407,825개의 elements와 82,138개의 node로 구성되어 있다. 0.1초동안 하악골 3부위에서 800 N으로 사선 방향의 힘을 가하였을 때 두 가지 재료에 따른 상악 치아, 상악골 및 두개골의 응력분포를 평가하였고 동일한 조건하에서 두 재료에 따른 뇌의 변위량을 비교하였다. 결과: 이 연구를 통해 다음과 같은 결과를 얻었다. 1. 상악치아에서 유효응력 값을 비교하였을 때 연질의 구강보호장치가 경질의 구강보호 장치보다 응력값이 유의차 있게 작게 나타났다 (P < .05). 2. 상악골과 두개골에서 응력값을 비교하였을 때 연질의 구강보호장치가 경질의 구강보호장치보다 응력값이 유의차 있게 작게 나타났다 (P < .05). 3. 경질의 구강보호장치에서 연질의 구강보호장치보다 상악치아 및 상악골과 두개골에 더 많은 응력집중부위를 보였다. 4. 경질의 구강보호장치와 연질의 구강보호장치 간에 하악 충격 시 뇌의 변위량은 연질의 구강보호장치 쪽이 크게 나타났으나 유의차는 없었다. 본 연구를 통하여 악골 충격 시에 경질 및 연질 구강보호장치가 상악골과 두개골에서의 응력분포에 미치는 양상을 알 수 있었지만, 아직도 이의 상관관계를 모두 파악하기에는 불충분한 점이 많으리라 생각되며, 스포츠 외상에 따른 구강보호장치의 재료에 따른 상관관계에 대하여 보다 더 많은 연구가 필요할 것으로 사료된다. Statement of problem & Purpose: The purpose of this study was to investigate the effect of a mouth guard material properties on the skull and brain when they were under impact loads on mandible. Material and methods: Two customized mouth protectors having different material propeerst ieach other were made for a female Korean who had no history of brain trauma, no cerebral diseases, nomal occlusion and natural dentition. The 3D finite element model of human skull and brain scanned by means of computed tomography was constructed. The FEM model of head was composed of 407,825 elements and 82,138 nodes, including skull, brain, maxilla, mandible, articular disc, teeth and mouth guard. The stress concentrations on maxillary teeth, maxilla and skull with two mouth guards were evaluated under oblique impact load of 800N onto mandibular 3 loading points for 0.1sec. And the brain relative displacement was compared in two different mouth guard materials under same condition. Result and Conclusion: The results were as follows; 1. In comparison of von Mises stress on maxillary teeth, a soft mouth guard material had significantly lower stress values on measuring point than a hard mouth protector materials (P < .05). 2. In comparison of von Mises stress on maxilla and skull, A soft mouth protector material had significantly lower stress values on measuring point than a hard mouth protector materials (P < .05). 3. For impact loads on mandible, there were more stress concentrated area on maxilla and skull with hard mouth guard than soft with mouth protector. 4. For impact loads on mandible, brain relative displacement had little relation with mouth guard material properties. In results of this study, soft mouth guard materials were superior to hard mouth guard materials for mandible impact loads for prevention of sports injuries. Although the results of this study were not enough to figure out the roles of needed mouth guard material properties for a human head, we got some knowledge of the pattern about stress concentration and distribution on maxilla and skull for impact loads with soft or hard mouth protector. More studies are needed to substantiate the relationship between the mouth guard materials and sports injuries.

브루나이 열대우림의 산림 유형별 지상부 바이오매스 추정

장민주,노유진,김형섭,이정민,손요환,Jang, Minju,Roh, Yujin,Kim, Hyung-sub,Lee, Jeongmin,Son, Yowhan 한국환경생물학회 2021 환경생물 : 환경생물학회지 Vol.39 No.3

본 연구의 목적은 동남아시아 열대우림의 대표 산림 유형인 MDF, PSF 그리고 HF에서 지상부 바이오매스를 추정하는 것이다. 브루나이에서 MDF, PSF 그리고 HF를 대상으로 각각 3개 지역을 선정하여 20 m×20 m 조사구를 지역마다 9개씩 설치하고 흉고직경 10 cm 이상인 임목의 흉고직경을 측정하였다. 지상부 바이오매스는 측정된 흉고직경과 바이오매스 상대생장식을 활용하여 추정되었다. 지상부 바이오매스는 MDF, PSF 그리고 HF에서 각각 603.3±159.9, 305.9±23.4 그리고 284.3±19.3 Mg ha^-1 순으로 나타났다. 산림 유형에 따라 지상부 바이오매스는 유의하게 차이가 있었으며, MDF에서 가장 높게 나타났다. 이는 흉고직경이 70 cm 이상인 거대목이 MDF에서 집중되어 출현했기 때문이다. 이러한 연구 결과는 산림 유형에 따라 거대목의 출현빈도가 다르며, 나아가 거대목의 출현이 지상부 바이오매스 추정에 영향을 주는 요인 중 하나라는 의미를 가진다. The aboveground biomass (AGB) was estimated in mixed dipterocarp forests (MDF), peat swamp forests (PSF), and heath forests (HF) in Brunei Darussalam. A total of 81 (20 m×20 m) plots were established for MDF, PSF, and HF in three regions. The diameter at breast height(DBH) of all live trees (DBH≥10 cm) was measured within the plots. The AGB was calculated using an allometric equation with the measured DBH. The AGB(Mg ha^-1) for MDF, PSF, and HF was 603.3±159.9, 305.9±23.4, and 284.3±19.3, respectively, and was significantly different among the forest types (p<0.05). The greater AGB in MDF than those in PSF and HF was due to the presence of emergent trees in MDF. The results showed that the number of emergent trees varied by forest type. Consequently, the appearance of the emergent trees could be one of the main factors affecting AGB in Southeast Asia's tropical rain forests.

부산신항 1단계에 적용된 SCP 개량지반의 압밀특성

정종범(Jong-Bum Jung),김형섭(Hyung-Sub Kim),박유철(Yu-Chul Prak),송영재(Young-Jae Song) 한국항해항만학회 2007 한국항해항만학회 학술대회논문집 Vol.2 No.춘계

SCP공법은 진동 또는 충격하중을 이용하여 연약점토 지반 중에 일정한 간격으로 모래 말뚝을 타설하여 연약지반 개량공사에 사용되는 대표적인 지반개량공법 중의 하나로서 부산신항의 가장 중요한 구조물인 안벽케이슨 구조물 기초지반 개량에 사용되었다. 부산신항 1단계 SCP 개량공법이 적용되는 연약층은 표준관입시험에 의해 N치가 15이하인 점성토지반을 대상으로 하고 있다. 부산신항 1단계 총 9선석에 적용된 SCP 개량심도는 약 DL.(-)65.0m에서 약 DL.(-)45.0m 정도이다. 본 논문에서는 개량심도를 기준으로 다음과 같이 심도인 DL.(-)50.0m 까지는 일반구간 SCP공법이라 칭하고, DL.(-)50.0m 이상인 구간에 대해서는 대심도 SCP 공법으로 분류하여 시공관리 및 압밀침하특성을 분석하였다.