화학기상증착법을 이용한 그래핀의 물성 조절: 그래핀과 질소-도핑된 그래핀

박상준,이임복,배동재,남정태,박병준,한영희,김근수,Park, Sang Jun,Lee, Imbok,Bae, Dong Jae,Nam, Jungtae,Park, Byung Jun,Han, Young Hee,Kim, Keun Soo 한국전력공사 2015 KEPCO Journal on electric power and energy Vol.1 No.1

본 연구에서는 그래핀의 인위적인 합성방법인 화학기상증착법을 활용하여 합성 파라미터들을 변화시켜줌으로써 그래핀의 물성을 조절하는 연구를 수행하였다. 먼저, 메탄가스를 탄소원으로 순수 그래핀을 합성하였고, 액상의 피리딘을 원료로 사용하여 질소가 도핑된 그래핀을 합성하였다. 각각의 그래핀의 물성은 라만 분광법, X선 광전자 분광법(XPS)을 통한 기초 광물성 측정과 게이트 전압에 따른 그래핀 채널의 전류-전압 응답특성을 통한 전기적 수송현상 측정에 의해 평가되었다. 메탄가스로 합성된 그래핀의 라만 분광 스펙트럼에서는 G-peak과 2D-peak가 선명히 보였고, XPS에서 C1s-peak가 선명하였고, 아울러 전하중성점은 게이트 전압 약 +4 V 정도에서 나타났다. 피리딘을 원료로 합성된 그래핀의 라만 분광 스펙트럼에서는 D-peak, G-peak 그리고 다소 약해진 2D-peak 등이 보였고, XPS에서는 C1s-peak은 물론 N1s-peak도 나타났으며, 전하중성점은 게이트 전압 약 -96 V 정도에서 나타났다. 결과적으로 우리는 화학기상증착법을 활용하여 그래핀의 물성을 성공적으로 조절하였다. In this research, pristine graphene was synthesized using methane ($CH_4$) gas, and N-doped graphene was synthesized using pyridine ($C_5H_5N$) liquid source by chemical vapor deposition (CVD) method. Basic optical properties of both pristine and N-doped graphene were investigated by Raman spectroscopy and XPS (X-ray photoemission spectroscopy), and electrical transport characteristics were estimated by current-voltage response of graphene channel as a function of gate voltages. Results for CVD grown pristine graphene from methane gas show that G-peak, 2D-peak and C1s-peak in Raman spectra and XPS. Charge neutral point (CNP; Dirac-point) appeared at about +4 V gate bias in electrical characterization. In the case of pyridine based CVD grown N-doped graphene, D-peak, G-peak, weak 2D-peak were observed in Raman spectra and C1s-peak and slight N1s-peak in XPS. CNP appeared at -96 V gate bias in electrical characterization. These result show successful control of the property of graphene artificially synthesized by CVD method.

ATM 서브망에서 MCS 멀티캐스트 구현을 위한 전송 제어 시스템의 성능 평가

박상준,이효준,김관중,김영한,김병기,Park, Sang-Joon,Lee, Hyo-Jun,Kim, Kwan-Joong,Kim, Young-Han,Kim, Byung-Gi 한국음향학회 1997 韓國音響學會誌 Vol.16 No.6

ATM 망으로 연결된 하나의 서브 네트워크에서 MCS(Multicast Server)에 의한 멀티캐스팅은 전송 폭주에 대해 효율적인 제어방식을 요구한다. 본 논문에서는 MCS를 이용하여 TCP 패킷에 대한 멀티캐스팅을 구현하고 버퍼의 효율적 전송제어를 위해 공통 버퍼를 가지는 EPD + SPD방식 (Early Packet Discard-same Source Packet Discard)을 제안한다. MCS에서 전송 버퍼에 대한 임계치를 넘어서면 버퍼에 오버플로우가 발생하기 이전에 셀을 폐기시키는 것으로 손상된 패킷의 전송을 막기 위하여 부분적 셀 폐기 대신 손상된 패킷 전체를 폐기하는 방식(EPD-Early Packet Discard)을 제공한다. 또한 TCP 패킷의 재전송 중복에 대한 부하를 줄이기 위해 동일한 송신측의 패킷을 폐기하는 방식 (SPD-same Source Packet Drop)을 제안한다. 시뮬레이션 결과에서는 전송 데이터 폐기에 대한 기존의 방식(Tail Drop), EPD 방식을 고려한 DFF(Drop From Front)와 본 논문에서 제안한 EPD + SPD방식과의 성능 분석을 한다. The multicasting of MCS(Multicast Server) requires a effective traffic control scheme to prevent buffer overflow on ATM subnetworks. This paper considers MCS multicasting to TCP packets, and propose EPD + SPD scheme(Early Packet Discard-same Source Packet Discard) using common buffer. When the threshold of output buffer is reached, MCS drops an entire packet prior to buffer overflow, so that corrupted packets will not be transmitted by the server. And SPD scheme show that the EPD + SPD results in higher TCP throughput than that of tail drop and EPD + DFF.

화침요법(火鍼療法)의 연구동향(硏究動向)과 D.I.T.I를 활용(活用)한 임상적(臨床的) 고찰(考察)

박상준,안수기,Park Sang-Jun,Ahn Soo-Gi 대한침구의학회 1998 대한침구의학회지 Vol.15 No.2

We have studied the clinical application of burning acupuncture by examining 18recent-published papers in the journal 'ZHONGGUO ZHENJIU(中國鍼灸)' for the bibliographical study and clinical study and have given medical treatment of burning acupuncture on 21 Patients who suffered 'the body chill symptoms(冷症)' at the oriental hospital of Won-Kwang University, Kwang-Ju. As a result, we have come to some conclusions as below. 1. The diseases for which the modern borning acupuncture is efficacious are widely extended to various kinds of field such as surgery, internal medicine, gynecology, ophthalmology, otolaryngology. etc. as well as numbness, meridian muscle disease(經筋病) mentioned in 'Neijing(內徑)' . 2. The effects of burning acupuncture therapy are wen zhuang yang qi(溫壯陽氣), sheng ji lian chuang(生肌斂瘡), san han chu shi(散寒除濕), qu fens zhi yang(祛風止痒), qu yu chu fu pai nong(祛瘀除腐排膿), san jie xiao zhong(散結消腫), zhi tong huan ji chu ma mu(止痛緩急除麻木), qing re xie hue jie du(淸熱瀉火解毒). 3. The recently reported diseases for which burning acupuncture is good are internal and external humeral epicondylitis, atheroma, menorrhalgia, thecal cyst, tragomaschalia, pruritus, traumatic onychophemia, gout of feet, prostatomegaly, aacne, supprative infection of body surface, snapping finger, backache, numbness, pyocyst etc. 4. The subjective symptoms of 'the body chill symptoms(冷症)' were, most of all, feeling cold accompanied by pain(16 case), while just 4 cases were feeling cold only. 5. In the related diseases of the body chill symptoms(冷症), feeling pain like arthralgia was the most case, and then dysmenorrhea, menorralgia, depression, anemia in order. 6. In the D.I.T.I before and after burning acupuncture treatment, 6 patients had shown 'excellent' effects and 8 patients had turned out 'good', while 7 patients had become'fair'. 7. In the degree of patient-satisfaction, 5 patients announced 'excellence' and 6 patients expressed 'good', 4 expressed 'fair', while the other 6 showed no change. 8. In the correlation of D.I.T.I and patient-satisfaction, the better the result of clinical treatment was, the more satisfied the patient was, however, in the case 'fair', we saw the degree of patient-satisfaction was relatively low, so we could admit the judging significance of D.I.T.I.

세분화된 탐색 영역을 이용한 고속 전영역 움직임 예측 알고리즘

박상준,진순종,정제창,Park, Sang-Jun,Jin, Soon-Jong,Jeong, Je-Chang 한국통신학회 2007 韓國通信學會論文誌 Vol.32 No.1C

We propose the fast full search algorithm that reduces the computation of the block matching algorithm which is used for motion estimation of the video coding. Since the conventional spiral search method starts searching at the center of the search window and then moves search point to estimate the motion vector pixel by pixel, it is good for the slow motion pictures. However the proposed method is good for the fast and slow motion because it estimates the motion in the new search order after partitioning the search window. Also, when finding the motion vector, this paper presents the method that reduces the complexity by computing the matching error in the order which is determined by local image complexity. The proposed algorithm reduces the computation up to 99% for block matching error compared with the conventional spiral full search algorithm without any loss of image quality. 본 논문에서는 비디오 부호화의 움직임 예측에 사용되는 블록 정합 알고리즘의 계산량을 줄이는 고속 전영역 탐색 알고리즘을 제안한다. 블록 정합 알고리즘에서 사용되는 기존의 나선형 탐색 방법은 탐색 영역의 중심에서 시작하여 탐색 지점을 화소 단위로 이동하면서 움직임 예측을 수행하기 때문에 움직임이 적은 영상에 적합하다. 본 논문에서는 탐색 영역을 작은 영역으로 세분화한 후 각 영역을 새로운 탐색 순서에 따라 움직임 예측을 수행함으로써 움직임이 많은 영상을 효과적으로 탐색할 수 있다. 또한 움직임 벡터 판정시 영상의 복잡도에 따라 최적의 순서로 비용을 계산하여 복잡도를 줄이는 방법을 제안한다. 실험 결과에서 제안하는 알고리즘이 기존의 나선형 전역 탐색 방법에 비해 예측화질의 열화 없이 최대 99%까지 계산량을 감소시키는 것을 확인할 수 있다.

파쇄횟수가 순환골재의 품질특성에 미치는 영향

박상준,Park, Sang-Jun 한국건설안전협회 2005 建設 安全技術 Vol.32 No.-

천문학적 재난 - 혜성ㆍ운석이 지구와 충돌하면 종말

박상준,Park, Sang-Jun 한국과학기술단체총연합회 2002 과학과 기술 Vol.35 No.12

천체가 지구에 충돌하면 흙먼지들이 하늘을 뒤덮어 태양빛을 차단, 몇년 동안 겨울이 이어지면서 기온이 내려간다. 또 충돌때 충격으로 지진, 화산폭발, 해일 등이 육지를 휩쓸게 된다. 또 겨울이 끝나면 온실효과가 일어나 기온이 상승하고 극지의 얼음이 녹아 고도가 낮은 육지는 물에 잠겨버린다.

당뇨 환자와 정상인의 스펙트럼 영역 빛간섭단층촬영을 통한 신경절세포-내망상층 두께 차이

박상준,문연성,김나래.Sang Jun Park. MD. Yeon Sung Moon. MD. PhD. Na Rae Kim. MD. PhD 대한안과학회 2014 대한안과학회지 Vol.55 No.10

Purpose: To analyze the difference of the ganglion cell-inner plexiform layer (GCIPL) thickness in diabetic and normal eyes of patients using spectral domain optical coherence tomography (OCT) (Carl Zeiss Meditec, Dublin, CA, USA). Methods: The authors compared and analyzed the difference of the GCIPL thickness measured with spectral domain optical coherence tomography (OCT) in 42 diabetic and 92 normal subjects. Results: The study subjects were divided into 3 groups: 92 normal subjects, 22 diabetic patients without diabetic retinopathy, and 26 diabetic patients with diabetic retinopathy. Presence of diabetes mellitus (DM) or diabetic retinopathy did not influence the retinal nerve fiber layer (RNFL) thickness. The GCIPL thickness tended to be thinner especially in the superior sector GCIPL. The GCIPL thickness of normal subjects, diabetes patients without diabetic retinopathy, and diabetic retinopathy patients was 82.24 ± 7.21 μm, 81.86 ± 9.53 μm, and 76.77 ± 14.13 μm, respectively, especially in the superior sector GCIPL (<EM>p</EM> = 0.029). Conclusions: Retinal ganglion cell layer thinning was induced by diabetes and diabetic retinopathy, and originated specifically from the superior part of the retina. J Korean Ophthalmol Soc 2014;55(10):1476-1480

과학SF - 테라포밍과 에코스피어 "인간이 거주할 우주식민지 조성"

박상준,Park, Sang-Jun 한국과학기술단체총연합회 2002 과학과 기술 Vol.35 No.11

Glycothermal법에 의한 ZnS 분말 합성 및 광촉매 특성

박상준,임대영,송정환,Park, Sang-Jun,Lim, Dae-Young,Song, Jeong-Hwan 한국재료학회 2017 한국재료학회지 Vol.27 No.9

ZnS powder was synthesized using a relatively facile and convenient glycothermal method at various reaction temperatures. ZnS was successfully synthesized at temperatures as low as $125^{\circ}C$ using zinc acetate and thiourea as raw materials, and diethylene glycol as the solvent. No mineralizers or precipitation processes were used in the fabrication, which suggests that the spherical ZnS powders were directly prepared in the glycothermal method. The phase composition, morphology, and optical properties of the prepared ZnS powders were characterized using XRD, FE-SEM, and UV-vis measurements. The prepared ZnS powders had a zinc blende structure and showed average primary particles with diameters of approximately 20~30 nm, calculated from the XRD peak width. All of the powders consisted of aggregated secondary powders with spherical morphology and a size of approximately $0.1{\sim}0.5{\mu}m$; these powders contained many small primary nanopowders. The as-prepared ZnS exhibited strong photo absorption in the UV region, and a red-shift in the optical absorption spectra due to the improvement in powder size and crystallinity with increasing reaction temperature. The effects of the reaction temperature on the photocatalytic properties of the ZnS powders were investigated. The photocatalytic properties of the as-synthesized ZnS powders were evaluated according to the removal degree of methyl orange (MO) under UV irradiation (${\lambda}=365nm$). It was found that the ZnS powder prepared at above $175^{\circ}C$ exhibited the highest photocatalytic degradation, with nearly 95 % of MO decomposed through the mediation of photo-generated hydroxyl radicals after irradiation for 60 min. These results suggest that the ZnS powders could potentially be applicable as photocatalysts for the efficient degradation of organic pollutants.

과학SF - SF와 SFX 영상매체의 미래, 영화 주인공의 얼굴 바뀔 수 있다

박상준,Park, Sang-Jun 한국과학기술단체총연합회 2001 과학과 기술 Vol.34 No.12