일간 빔 출력 확인을 위한 평가도구인 Machine Performance Check의 유용성 평가

이상현,안우상,이우석,최진혁,김선연,Lee, Sang Hyeon,Ahn, Woo Sang,Lee, Woo Seok,Choi, Jin Hyeok,Kim, Seon Yeon 대한방사선치료학회 2017 대한방사선치료학회지 Vol.29 No.2

목 적: Machine Performance Check (MPC)는 Electronic Portal Imaging Device(EPID)를 기반으로 빔 출력을 별도의 설치 없이 측정할 수 있는 장점을 지닌 자체 검사 소프트웨어이다. 본원에서는 MPC와 QA Beamchecker PLUS 간의 일간 빔 출력을 비교 및 상관관계를 분석하여 MPC의 유용성을 확인하고자 하였다. 대상 및 방법: 본 실험을 진행하기 위해 선형가속기(Truebeam 2.5)를 이용하였고, 광자선(6 MV, 10 MV, 15 MV, 6 MV-FFF, 10 MV-FFF), 전자선(6 MeV, 9 MeV, 12 MeV, 16 MeV, 20 MeV) 총 10개의 에너지를 대상으로 5 개월간 치료 전 빔 출력을 MPC와 QA Beamchecker PLUS로 측정하여, 총 80 회의 데이터를 획득하였다. Pearson 상관계수를 사용하여 MPC와 QA Beamchecker PLUS 간의 빔 출력을 비교 및 상관관계를 평가하였다. Pearson 상관계수는 0.8 이상은 아주 강함, 0.6 이상 0.8 미만 강함, 0.4 이상 0.6 미만 보통, 0.2 이상 0.4 미만 약함, 0.2 미만 아주 약함을 의미한다. 결 과: MPC와 QA Beamchecker PLUS 모두 일간 빔 출력 일치도는 2 % 이내로 나타났다. MPC의 빔 출력은 광자선이 $0.29{\pm}0.26%$, 전자선이 $0.30{\pm}0.26%$로 나타났고, QA Beamchecker PLUS의 빔 출력은 광자선이 $0.31{\pm}0.24%$, 전자선이 $0.33{\pm}0.24%$로 나타났다. MPC와 QA Beamchecker PLUS 사이의 Pearson 상관계수는 광자선의 경우 15 MV에서는 아주강함, 6 MV, 10 MV, 6 MV-FFF 그리고 10 MV-FFF에서는 강함으로 나타났고, 전자선의 경우 16 MeV, 20 MeV에서 강함, 9 MeV, 12 MeV에서 보통, 6 MeV에서 아주 약함으로 나타났다. 결 론: MPC는 일간 빔 출력 평가 면에서 광자선과 고에너지 전자선에서는 QA Beamchecker PLUS와 강한 상관관계로 보임을 확인할 수 있었다. 다만, 저에너지 전자선(6 MeV)에서는 낮은 상관관계를 보였지만, 관찰기간동안 MPC, QA Beamchecker PLUS 모두 빔 출력 일치도는 2 % 이내로 일간 빔 출력 확인 용도로는 적절할 것으로 판단된다. MPC는 기존의 일간 빔 출력 측정 도구 보다 빠르게 수행 할 수 있어 사용자 입장에서 효과적인 방법인 것으로 사료된다. Purpose: Machine Performance Check (MPC) is a self-checking software based on the Electronic Portal Imaging Device (EPID) to measure daily beam outputs without external installation. The purpose of this study is to verify the usefulness of MPC by comparing and correlating daily beam output of QA Beamchecker PLUS. Materials and Methods: Linear accelerator (Truebeam 2.5) was used to measure 10 energies which are composed of photon beams(6, 10, 15 MV and 6, 10 MV-FFF) and electron beams(6, 9, 12, 16 and 20 MeV). A total of 80 cycles of data was obtained by measuring beam output measurement before treatment over five months period. The Pearson correlation coefficient was used to evaluate the consistency of the beam output between the MPC and the QA Beamchecker PLUS. In this study, if the Pearson correlation coefficient is; (1) 0.8 or higher, the correlation is very strong (2) between 0.6 and 0.79, the correlation is strong (3) between 0.4 and 0.59, the correlation is moderate (4) between 0.2 and 0.39, the correlation is weak (5) lower than 0.2, the correlation is very weak. Results: Output variations observed between MPC and QA Beamchecker PLUS were within 2 % for photons and electrons. The beam outputs variations of MPC were $0.29{\pm}0.26%$ and $0.30{\pm}0.26%$ for photon and electron beams, respectively. QA Beamchecker PLUS beam outputs were $0.31{\pm}0.24%$ and $0.33{\pm}0.24%$ for photon and electron beams, respectively. The Pearson correlation coefficient between MPC and QA Beamchecker PLUS indicated that photon beams were very strong at 15 MV, and strong at 6 MV, 10 MV, 6 MV-FFF and 10 MV-FFF. For electron beams, the Pearson correlation coefficient were strong at 16 MeV and 20 MeV, moderate at 9 MeV and 12 MeV, and very weak at 6 MeV. Conclusion: MPC showed significantly strong correlation with QA Beamchecker PLUS when testing with photon beams and high-energy electron beams in the evaluation of daily beam output, but the correlation when testing with low-energy electron beams (6 MeV) appeared to be low. However, MPC and QA Beamchecker PLUS are considered to be suitable for checking daily beam output, as they performed within 2 % of beam output consistency during the observation. MPC which can perform faster than the conventional daily beam output measurement tool, is considered to be an effective method for users.

Sol-gel법에 의한 박막태양전지용 CuInS₂ 박막의 증착과 특성

이상현,이승엽,박병옥,Lee, Sang-Hyun,Lee, Seung-Yup,Park, Byung-Ok 한국결정성장학회 2011 한국결정성장학회지 Vol.21 No.4

박막 태양전지의 저가 고효율화를 실현하기 위해 넓은 면적의 기판 위에 코팅이 가능하며 진공의 유자가 필요 없기 때문에 장치가 간단하고 고순도의 균질한 박막을 얻을 수 있고 박막의 조성을 쉽게 조절할 수 있는 Sol-Gel법을 이용 하였다. Se보다 저가이며 독성이 없고 풍부한 원료인 S로 치환하여 사용하며 Cu/In비 값을 조절하고 tetragonal chalcopyrite $CuInS_2$의 열처리 온도에 따른 박막의 구조적, 광학적 특성에 미치는 변수들의 영향을 알아보았다. XRD pattern을 관찰한 결과 Cu/In비가 1.0일 때 $2{\theta}=27.9^{\circ}$에서 주피크가 가장 강하게 나타났으며 (112) 방향의 배향성을 가진 chalcopyrite상임을 확언 할 수 있었다. 열처리 온도가 증가할수록 (112) 면의 강도가 커지며 $500^{\circ}C$에서 열처리를 한 $CuInS_2$ 박막은 tetragonal 구조의 화학량론적 $CuInS_2$ 특징을 나타내고 본 실험의 샘플의 격자상수를 측정한 값이 a = 5.5032, c = 11.1064 ${\AA}$이며 JCPDS(Joint Committee on Powder Diffraction Standards)에 보고된 데이터 a = 5.523, c = 11.14 ${\AA}$과 거의 일치하였다. 광학적 특성을 알아보기 위해 측정한 광투과율은 가시광선 영역(380~770 nm)에서 전체적으로 30% 이하로 나타났다. $CuInS_2$ thin films were prepared using a sol-gel spin-coating method. That makes large scale substrate coating, simple equipment, easy composition control available. The structural and optical properties of $CuInS_2$ thin films that include less toxic materials (S) instead of Se, tetragonal chalcopyrite structure. Copper acetate monohydrate ($Cu(CH_3COO)_2{\cdot}H2O$) and indium acetate ($In(CH_3COO)_3$) were dissolved into 2-propanol and l-propanol, respectively. The two solutions were mixed into a starting solution. The solution was dropped onto glass substrate, rotated at 3000 rpm, and dried at $300^{\circ}C$ for Cu-In as-grown films. The as-grown films were sulfurized inside a graphite container box and chalcopyrite phase of $CuInS_2$ was observed. To determine the optical properties measured optical transmittance of visible light region (380~770 nm) were less than 30 % in the overall. The XRD pattern shows that main peak was observed at Cu/In ratio 1.0 and its orientation was (112). As annealing temperature increases, the intensity of (112) plane increases. The unit cell constant are a = 5.5032 and c = 11.1064 $\AA$, and this was well matched with JCPDS card. The optical transmittance of visible region was below than 30 %.

콘크리트의 탄산화 관점에서 CO₂ 배출량-흡수량 평가에 관한 연구

이상현,이성복,이한승,Lee, Sang-Hyun,Lee, Sung-Bok,Lee, Han-Seung 한국콘크리트학회 2009 콘크리트학회논문집 Vol.21 No.1

콘크리트는 생산과정에서 다량의 이산화탄소를 배출하는 시멘트를 사용하기 때문에 반친환경적 재료로 인식되고 있다. 하지만 콘크리트는 사용기간 중 탄산화 과정을 통하여 대기중의 이산화탄소를 흡수한다. 이에 본 연구에서는 기존문헌 고찰을 통하여 1) 콘크리트 내 탄산화 가능한 물질의 농도, 2) 탄산화된 콘크리트의 체적, 3) 이산화탄소 분자량을 이용, 탄산화를 통한 콘크리트의 이산화탄소 흡수량의 정량적 산출 방법을 제시하였다. 또한 콘크리트 생산에 사용되는 재료들의 이산화탄소 배출량 자료를 이용하여 단위 콘크리트 생산에 따른 이산화탄소 배출량을 정량적으로 산출하였다. 이러한 콘크리트의 이산화탄소 흡수량 및 배출량의 정량적 산출방법을 이용하여 실제 사용중인 아파트 건축물 1동을 대상으로 하여 콘크리트의 생산에 따른 배출량과 사용기간에 따른 이산화탄소 흡수량을 정량적으로 산출하여 이산화탄소의 배출량-흡수량 평가를 실시하였다. 그 결과 건축물을 40, 60, 80년 사용시, 사용된 콘크리트의 이산화탄소 배출량 대 흡수량의 비율이 3.65, 4.47, 5.18%로 나타났다. 본 연구는 콘크리트 생산 및 사용에 따른 이산화탄소 배출량-흡수량의 정량적 산정방법에 연구의 목적을 두었으며 이산화탄소 배출량-흡수량 평가 결과 구조물을 80년 사용할 시 약 5.18%로 그 값이 미비하였으나 시멘트의 혼화재 치환율 증가를 통한 배출량 저감과 탄산화 체적 증가를 통한 이산화탄소 흡수량 증가를 통해 배출량-흡수량을 향상시킬 수 있으며, 향후 콘크리트의 이산화탄소 배출량-흡수량 평가에 본 연구의 방법이 유용하게 활용될 수 있을 것으로 판단된다. A concrete is considered unfriendly-environmental material because it uses cement which emits much $CO_2$ during producing process. However, a concrete absorbs $CO_2$ through carbonation process during service life. In this paper how much concrete absorbs $CO_2$ through carbonation was calculated using 1) concentration of carbonatable substances in concrete, 2) carbonated volume of concrete, 3) molecular weight of $CO_2$ based on references and the method was proposed. $CO_2$ emission from producing $1m^3$ concrete was calculated based on $CO_2$ emission datum of materials used in concrete. From using these methods that calculate $CO_2$ emission and absorption of concrete, assessment of $CO_2$ emission-absorption against a real apartment was conducted by subtracting absorption $CO_2$ according to service life from $CO_2$ emission in the process of making concrete. As a result, a ratio of absorption over emission of $CO_2$ through concrete carbonation according to service life 40, 60, 80 years was assessed about 3.65, 4.47, 5.18%. An objective of this study is to propose how to calculate emission - absorption of $CO_2$ from producing and using concrete. Although the result value, emission - absorption of $CO_2$, is 5.18% very low when the service life of an apartment is 80years, the value can be improved by reducing emission from using blended cement such as blast furnace slag or increasing replacement ratio of cement and increasing carbonated volume of concrete from expanding service life of a building. This study may be useful when $CO_2$ emission - absorption of concrete is evaluated in the further study.

MR감쇠기를 장착한 토글가새시스템을 이용한 건축구조물의 지진응답제어

이상현,황재승,민경원,이명규,Lee Sang-Hyun,Hwang Jae-Seung,Min Kyung-Won,Lee Myoung-Kyu 한국전산구조공학회 2006 한국전산구조공학회논문집 Vol.19 No.3

본 연구에서는, 지진하중에 의해 구조물에 발생하는 진동을 제어하기 위하여 토글 시스템의 비선형성을 연구하고, 자기유변유체(MR) 감쇠기를 장착한 토글 가새시스템의 성능을 평가하였다. Bingham 모델로 표현되는 MR감쇠기의 제어력이 속도의 함수인 점을 고려하여, 토글 가새시스템에 의한 속도증폭계수를 계산하였고 토글 형태에 대한 증폭계수효과를 평가하였다. 특히 강한 지진하중에서 쉐브론과 대각가새 등의 전형적인 가새시스템에 장착된 MR감쇠기가 충분한 응답감소효과를 제공하지 못하는 경우에, 토글 가새시스템을 사용하여 제어성능을 크게 강화시키는 것을 수치해석 결과를 통하여 확인하였다. In this paper, the performance of a toggle brace-MR damper system is evaluated for the control of the structure excited by earthquake load and the non-linearity of the toggle system is investigated. Considering that the control force of MR damper described by Bingham model is a function of velocity, velocity amplification factor by the toggle brace system is calculated and the effect of toggle configuration on the amplification factor is also evaluated. Numerical results show that the control performance can be largely enhanced using toggle brace system especially for the case that the MR damper installed with conventional brace system such as Chevron and diagonal cannot provide enough control force under severe earthquake load.

전기로를 이용한 Si || SiO₂/Si₃N₄ || Si 이종기판쌍의 직접접합

이상현,이상돈,서태윤,송오성,Lee, Sang-Hyeon,Lee, Sang-Don,Seo, Tae-Yun,Song, O-Seong 한국재료학회 2002 한국재료학회지 Vol.12 No.2

We investigated the possibility of direct bonding of the Si ∥SiO$_2$/Si$_3$N$_4$∥Si wafers for Oxide-Nitride-Oxide(ONO) gate oxide applications. 10cm-diameter 2000$\AA$-thick thermal oxide/Si(100) and 500$\AA$-Si$_3$N$_4$LPCVD/Si (100) wafers were prepared, and wet cleaned to activate the surface as hydrophilic and hydrophobic states, respectively. Cleaned wafers were premated wish facing the mirror planes by a specially designed aligner in class-100 clean room immediately. Premated wafer pairs were annealed by an electric furnace at the temperatures of 400, 600, 800, 1000, and 120$0^{\circ}C$ for 2hours, respectively. Direct bonded wafer pairs were characterized the bond area with a infrared(IR) analyzer, and measured the bonding interface energy by a razor blade crack opening method. We confirmed that the bond interface energy became 2,344mJ/$\m^2$ when annealing temperature reached 100$0^{\circ}C$, which were comparable with the interface energy of homeogenous wafer pairs of Si/Si.

반원형 리블렛 상부 난류경계층의 유동 구조 연구

이상현,이상준,Lee, Sang Hyun,Lee, Sang Joon 대한기계학회 1999 大韓機械學會論文集B Vol.23 No.7

The near-wall flow structures of turbulent boundary layer over riblets having semi-circular grooves were investigated experimentally for the drag decreasing ($s^+=25.2$) and drag increasing ($s^+=40.6$) cases. The field of view used for tho velocity field measurement was $6.75{\times}6.75mm^2$ in physical dimension, containing two grooves. One thousand instantaneous velocity fields over the riblets were extracted for each case of drag increase and decrease. For comparison, five hundreds instantaneous velocity fields over a smooth flat plate were also obtained under the same flow conditions. To see the global flow structure qualitatively, the flow visualization was also performed using the synchronized smoke-wire technique. For the drag decreasing case ($s^+=25.2$), most of the streamwise vortices stay above the riblets, interacting with the riblet tips. The high-speed in-rush flow toward the riblet surface rarely influences the flow inside tho riblet valleys submerged in the viscous sublayer. The riblet tips seem to impede the spanwise movement of the longitudinal vortices and induce secondary vortices. The turbulent kinetic energy in the riblet valley is sufficiently small to compensate the increased wetted area of the riblets. In addition, in the logarithmic region, the turbulent kinetic energy are small or almost equal to that of a smooth flat plato. For the drag increasing case ($s^+=40.6$), however, the streamwise vortices move into the riblet valley freely, interacting directly with the riblet inner surface. The penetration of the high-speed in-rush flow on the riblets increases tho skin-friction. The turbulent kinetic energy is increased in the riblet valleys and even in the outer region compared to that over a flat plate.

입력전류 파형 개선형 단상 정류기의 토폴로지

이상현(Sang-Hyun Lee),박진민(Jin-Min Park),문상필(Sang-Pil Mun),서기영(Ki-Young Suh) 한국조명·전기설비학회 2003 한국조명·전기설비학회 학술대회논문집 Vol.2003 No.-

For small capacity rectifier circuits such as these for consumer electronics and appliances, capacitor input type rectifier circuits are generally used. Consequently, various harmonics generated within the power system become a serious problem. Various studies of this effect have been presented previously. However, most of these employ switching devices, such as FETs and the like. The absence of switching devices makes systems more tolerant to over-load, and brings low radio noise benefits. We propose a power factor correction scheme using a LC resonant in commercial frequency without switching devices. In this method, it makes a sinusoidal wave by widening conduction period using the current resonance in commercial frequency, Hence the harmonic characteristics can be significantly improved, where the lower order harmonics, such as the fifth and seventh order are much reduced. The result are confirmed by the theoretical and experiment implementations.

평균역학고도장과 인공위성고도계 자료를 이용한 동해 표층해류 추산

이상현,변도성,최병주,이은일,Lee, Sang-Hyun,Byun, Do-Seong,Choi, Byoung-Ju,Lee, Eun-Il 한국해양학회 2009 바다 Vol.14 No.4

인공위성 고도계로 측정한 해수면 높이 자료를 사용하여 준 실시간 동해 표층해류를 추정하기 위해, 세 가지 방법으로 평균 역학지형(또는 평균 해류장)을 계산하고 각각의 특징들을 살펴보았다. 프랑스 AVISO(Archiviing, Validation and Interpretation of Satellite Oceanographic data)는 인공위성 고도계 자료와 수치모델을 이용하여 전 지구 해양에 대하여 수평적으로 $0.25^{\circ}$의 해상도를 갖는 평균 역학지형을 계산하고 지형류 방정식을 적용하여 평균 해류장을 만들어 제공하고 있다. 동해에서 장기간 관측한 수온과 염분 자료를 사용하여 500 dbar를 기준면으로 사용한 역학적 해면(steric height)을 계산하고 이를 평균 여각지형으로 환산하였다. 또한 14년 동안 동행의 표층을 이동한 표층뜰개들(ARGOS)의 궤적을 이용하여 평균 해류장을 구하였다. 인공위성 고도계로 관측한 해수면 편차와 세 가지 평균 역학지형을 합하여 절대 역학지형을 얻고, 각각의 절대 역학지형에 지형류 방정식을 적용하여 세 가지 표층해류를 추정하였다. 각 방법으로 추정된 표층해류를 2005년에 동해 남서부 해역에서 선박장착 초음파 해류계(ADCP)로 관측한 해류 자료와 정량적으로 비교하였다. 육지에서 50 km 이상 떨어진 해역에서는 인공위성 고도계로 측정한 해수면 자료에 지형류 방정식을 적용하여 구한 표층해류와 현장 관측 해류의 상관계수(R)가 0.58~0.73이며 두 자료의 제곱 평균 제곱근 편차(Root Mean Square Deviation, RMSD)는 $17.1{\sim}21.8cm\;s^{-1}$이다. 육지에서 50 km 이내의 연안에서 두자료의 R이 0.06~0.46로 상대적으로 낮고 RMSD는 $15.5{\sim}28.0cm\;s^{-1}$이다. 이처럼 연안에서는 인공위성 고도계로 관측한 해수면 높이 자료의 오차가 크므로 향후 연안에 대해서는 새로운 표층해류 추정 방법에 대한 추가 연구가 필요하다. In order to estimate sea surface current fields in the East Sea, we examined characteristics of mean dynamic topography (MDT) fields (or mean surface current field, MSC) generated from three different methods. This preliminary investigation evaluates the accuracy of surface currents estimated from satellite-derived sea level anomaly (SLA) data and three MDT fields in the East Sea. AVISO (Archiving, Validation and Interpretation of Satellite Oceanographic data) provides a MDT field derived from satellite observation and numerical models with $0.25^{\circ}$ horizontal resolution. Steric height field relative to 500 dbar from temperature and salinity profiles in the East Sea supplies another MDT field. Trajectory data of surface drifters (ARGOS) in the East Sea for 14 years provide another MSC field. Absolute dynamic topography (ADT) field is calculated by adding SLA to each MDT. Application of geostrophic equation to three different ADT fields yields three surface geostrophic current fields. Comparisons were made between the estimated surface currents from the three different methods and in-situ current measurements from a ship-mounted ADCP (Acoustic Doppler Current Profiler) in the southwestern East Sea in 2005. For offshore areas more than 50 km away from the land, the correlation coefficients (R) between the estimated versus the measured currents range from 0.58 to 0.73, with 17.1 to $21.7\;cm\;s^{-1}$ root mean square deviation (RMSD). For coastal ocean within 50 km from the land, however, R ranges from 0.06 to 0.46 and RMSD ranges from 15.5 to $28.0\;cm\;s^{-1}$. Results from this study reveal that a new approach in producing MDT and SLA is required to improve the accuracy of surface current estimations for the shallow costal zones of the East Sea.

四君子湯이 免疫機能에 미치는 影響

이상현,정명,임규상,윤용갑,Lee, Sang-Hyun,Jung, Myung,Lim, Kyu-Sang,Yun, Yong-Gab 대한한방안이비인후피부과학회 2015 한방안이비인후피부과학회지 Vol.28 No.3

Objectives : The extract of Sagunja-tang has been traditionally used for restorative treatment of constitutional weakness, vascular and immune disorder, and nervous disease in Oriental country. This study investigated the regulatory effects of Sagunja-tang on the expression, production, and activity of immune mediators.Methods : In this study, the extract of Sagunja-tang was prepared by extracting with distilled water at 100$^{\circ}C$ for 2.5h. The extract was freeze-dried following filtration through 0.45${{\mu}m}$ filter. The extract was dissolved in Hank's balanced salt solution (HBSS) and filtered again through 0.45${{\mu}m}$ filter before use. The level of nitrite, an oxidative product of nitric oxide(NO) was measured in the culture medium by the Griess reaction. The levels of prostaglandin E₂(PGE₂), Th1 cytokines (IFN-${\gamma}$, IL-2) and Th2 cytokines(IL-4, IL-5, IL-13) were measured by enzyme-linked immunosorbent assay and the protein levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression were determined by Western blot analysis. Also examined the effects of the extract on T-cell proliferation and cytotoxic activity of natural killer cells.Results : In this investigation, Production levels of Th2 cytokines (IL-4, IL-5, IL-13) was inhibited in a dose dependent manner by treatment with the extract. I also found that the extract increased T-cell proliferation and cytotoxic activity of natural killer cells in a dose-dependent manner.Conculsions : These results suggest that the water extract of Sagunja-tang may be useful for a therapeutic drug against a sickly constitution and immune diseases, probably by regulating the production of immune mediators.

UBV CCD PHOTOMETRY OF OPEN CLUSTER NGC 1907 AND NGC 1912

이상현,이시우,Lee, Sang-Hyeon,Lee, Si-Woo 한국천문학회 1996 天文學論叢 Vol.11 No.1

Galactic open clusters NGC 1907 and NGC 1912 are known as a binary cluster candidate by Subramaniam et al.(1995). With the SNUO 0.6m telescope, UBV CCD photometric observations were performed for 62 stars in NGC 1907 within the area of $8'{\times}8'$ and 203 stars in NGC 1912 within the area of $15'{\times}15'$ area. We obtained C-M and C-C diagrams. Their mean reddenings are E(B-V) = $0.50{\pm}0.03$ for NGC 1907 and $0.27{\pm}0.03$ for NGC 1912. The distance moduli are estimated as $10.9{\pm}0.15$ and $10.4{\pm}0.10$ for NGC 1907 and NGC 1912, respectively. The ages for these clusters are $400{\pm}50Myr$ for NGC 1907 and $150{\pm}30Myr$ for NGC 1912. The distance difference of the two clusters is 300pc and the age difference is 150Myr. These results imply that the two clusters are not physically connected.