海事衛星(MARISAT)시스템의 現況과 展望 <上>

홍석민,최광제,윤범석,이영희 한국해사문제연구소 1978 (月刊)海洋韓國 Vol.53 No.-

산소 혼합비에 따른 Ba_(0.7)Sr_(0.3)TiO₃박막의 유전체 특성

홍석민,임성민,김호건,김옥경 한양대학교 이학기술연구소 1999 이학기술연구지 Vol.1 No.-

Ba과 Sr의 화학당량비를 조절하여 Ba_(0.7)Sr_(0.3)TiO₃분말 시료를 제조하여 각각 1,200℃와 1,300℃에서 calcining과 sintering을 실시한 후 3 inch 성형틀로 Ba_(0.7)Sr_(0.3)TiO₃인 sputtering target를 제작하였다. MIM구조의 capacitor를 위하여 하부전극을 Pt(1500Å)/TiN(2000Å)/SiO₂/Si로 하고, 제작한 target를 이용하여 RF sputtering방법으로 BST박막을 증착하였다. 제작한 박막의 결정구조를 X-선 회절계(XRD)로 분석한 후 Al을 상부전극으로 증착하여 축전기구조로 C-V와 I-V의 전기적 특성을 얻었다. 제작된 박막의 결정구조를 XRD 측정으로 확인한 결과 550℃ 이상의 기판온도에서 결정성장이 양호함을 보였다. 유전상수와 유전손실이 기판온도와 sputtering 가스의 산소 혼합비에 영향을 받는 것으로 확인되고 I-V를 통한 전기적 특성에서 전도기구가 Schottky 장벽에 의한 것과 높은 인가전압에서 space charge limited (SCL) 전도 특성을 보였고, 누설전류의 값은 표면구조의 영향으로 산소가스의 증가에 따라 감소하였다. Ba_(0.7)Sr_(0.3)TiO₃powders were prepared by changing stoichiometry of Pb and Ba. After they were calcined and sintered at 1200℃ and 1300℃ respectively, BST sputtering targets were made in 3 inch mould. For MIM structure capacitors, Pt(1500Å)/TiN(2000Å)/SiO₂/Si were used for bottom electrodes and the BST thin films were sputtered on bottom electrodes. After we analysed their structures by XRD, Al was evaporated on the BST films for MIM capacitor and we investiaged the electrical properties by measuring of C-V and I-V. We found that the structures of the films showed good crystalllinity above 550℃ from the results of XRD measurements. We supposed that the dielectric constant and dielectric loss of films were affected with substrate temperature and oxygen ratio of sputtering gas. In I-V behavior, we supposed that the conduction mechanism was Schottky conduction and space charge limited(SCL) conduction in high voltage range.

중국의 IT 요람 쑤저우 공업원구 (2)

홍석민 주택산업연구원 2007 HOUSING ISSUE Vol.25 No.-

실시간 열 영상 획득 및 신호처리 기술

홍석민,송인섭,윤은숙,Hong, Seok-Min,Song, In-Seop,Yun, Eun-Suk 대한전자공학회 1993 전자공학회지 Vol.20 No.10

기획특집 1: 군사용 전자광학 기술의 현재와 미래 -전자광학기술의 군사적 응용 및 전망

홍석민,Hong, Seok-Min 한국광학기기산업협회 2010 光學世界 Vol.130 No.-

군사용 전자광학장비는 1970년대 중반부터 국방과학연구소를 중심으로 관련 방산업체들이 협력하여 연구개발한 결과, 비교적 짧은 시간에 선진국 수준의 기술들이 확보되었다. 특히 생산된 전자광학장비는 군의 감시정찰 능력 증대에 활용되었고 대부분의 전술급 감시정찰 영상 장비나 사격통제용 영상센서들이 이제는 독자 개발, 생산되고 있다. 전자광학장비는 선진국에 비해 비용대비 투자 효과면에서 우위를 점하고 있기 때문에 국내 수요 뿐 아니라 세계시장을 겨냥한 수출을 적극적으로 추진해야 할 시점으로 보여지며 기술 확보를 위한 방산전문업체와 우수 중소기업의 참여 확대가 요구되고 있다.

광고 대행사와 제작사의 사회연결망 분석 : 광고 대행사의 소유형태와 규모가 거래관계에 미친 영향

홍석민,윤태일,이기홍 한국방송광고공사 2005 광고연구 Vol.0 No.66

이 연구는 광고시장개방이 한국 광고산업에 실질적으로 미치는 영향을 규명하기 위해서, 2002년 산업자료를 바탕으로 대행사와 방송광고 제작사 사이의 거래연결망을 분석해보았다. 특히 사회연결망 분석(Social Network Analysis; SNA)의 틀을 원용하여, 광고 대행사의 소유형태(다국적 대행사 대 국내 대행사) 및 규모(상위권 대행사 대 중위권 대행사)에 따라 연결망에 차이가 있는가를 통계적으로 검증해 보았다. 분석결과 다국적 대행사가 국내 대행사보다, 그리고 상위권 대행사가 중위권 대행사보다 거래연결망의 구조 자체가 더 밀도가 높고 다양하여 효율적인 것으로 나타났다. 또, 이들 대행사의 중앙성(centrality) 지표가 높아 제작사와의 거래연결망에서 더 중심적인 위치를 차지하는 것으로 밝혀졌다. 특히 중앙성 지표에 대한 대행사의 소유형태와 규모 사이의 상호작용 효과는 연결정도 중앙성, 사이 중앙성, 위세 중앙성 3가지 지표 모두에서 나타났다. 또 중앙성 지표가 높은 대행사일수록 방송매출액, 순위, 종업원 수, 1인당 취급액 등의 기업성과 관련 지표에서도 우수성을 나타냈다. 이러한 분석결과에 대한 이론적 실무적 함의와 국내 광고산업의 경쟁력 제고를 위한 제언사항을 논의했다. Prior studies regarding Korea’s advertising industry have almost exclusively examined practitioners’ perceptions of changes in the advertising industry as global advertising agencies launched business in Korea. This study on Korea’s advertising market, however, used a unprecedented approach by looking into the relationship between advertising agencies and advertising production companies through the framework of social network analysis. It tested if there existed significant difference by ownership(global vs. local) and size(the largest 10 agencies vs. the rest) in maintaining business networks. Results from this study indicate that the global advertising agencies show stronger network density and centrality, more diversification, and more efficiency than the local advertising agencies in terms of inter-organizational relationship. Additionally, the interaction effect existed between the ownership and the size of advertising agencies by centrality index. Finally, the higher centrality index among agencies is, the higher billing and ranking are. The end of the paper offers further theoretical and practical implications of the analyses and suggestions to improve Korean advertising agencies’ business performance.

RF 마그네트론 스퍼터링 방법에 의한 (Ba, Sr)TiO₃박막의 특성

홍석민,조정희,김호건,김옥경 漢陽大學校 工學技術硏究所 1996 工學技術論文集 Vol.5 No.1

A sputtering target(BaxSr1-xTiO3) is obtained by changing the mol% of Ba and Sr. Pt is evaporated on the SiO2/Si substrate as a bottom electrode, and subsequently the BaxSr1-xTiO3 thin film is sputtered. Or, for obtaining the MIS structure Pt is not used, and directly thin film is sputtered on the Si substrate. Then, the capacitor structures(MIM, MIS) have been obtained by evaporating Al as a top electrode after post-annealing. Our results show that produced thin firm is found to have Perovskite structure according to the XRD measurement and shows better crystal growing phenomena on SiO2/Si substrate than those on Si substrate. And, the existence of polarization is recognized by the hysteresis loop. The capacitor(MIM) structure of BaxSr1-xTiO3 thin film shows that the dielectric constant is increased as the mol% of Ba and the post-annealing temperature increase. MIS structure shows a increase of capacitance with increasing the mol% of Ba.

Sol-Gel 법으로 제작한 (Pb_xBa_₁-_x)TiO₃박막의 특성에 관한 연구

홍석민,이정아,조정희,김옥경 漢陽大學校 工學技術硏究所 1996 工學技術論文集 Vol.5 No.1

We tried to find optimal condition of (PbxBa1-x)TiO3(x=0.0, 0.2, 0.5, 0.8, 1.0) thin films produced by sol-gel spin coating. Barium acetate, Lead acetate trihydrate and Ti-isopropoxide are used as the coating sol for producing the thin film, and acetic acid, methanol, and distilled water are used as the solvent. It is found that the manufactured sol was at the most stable condition when the component content satisfied H2O/Ba=65, after observing the state transition for a specified period. We coated sol for coating on the various kinds of substrate and pre-annealed on 68℃ and 460℃. Then we annealed them on 700℃ for 30 minutes and found that they showed a good growth of crystal by the XRD measurement. We selected Pt as the bottom electrode, using the substrate Pt/SiO2/Si in order, we raised the different conditional thin films and obtained the capacitor by evaporating Al as the top electrode. We measured the electric capacitance and dielectric loss by changing the frequency for three step as 1, 10, 100kHz for each and calculated the dielectric constant. The dielectric constant of the thin film (PbxBa1-x)TiO3 was decreased below x=0.8 and increased upto x=1.0 as x increases.

Contrast Echo-A Simple Diagnostic Tool for a Coronary Artery Fistula

홍석민,윤세정,임세중 대한심장학회 2012 Korean Circulation Journal Vol.42 No.3

Coronary artery fistulas have been diagnosed with aortography, coronary angiography, and coronary computed tomography (CT). A large fistula can be occasionally found as a mass lesion on echocardiography but cannot be easily confirmed. Here, we report a new diagnostic approach to coronary artery fistulas using a contrast agent and transthoracic echocardiography. Transthoracic echocardiography of a 46-year-old female suffering from dyspnea revealed suspicious small turbulent flow in the main pulmonary artery. Following infusion of a contrast agent, we found whitish flow in the main pulmonary artery during the diastolic phase, and aortic CT revealed two huge right coronary artery fistulas in the main pulmonary artery. A simple diagnostic approach to a coronary artery fistula using contrast agent helped us confirm the diagnosis because of the typical diastolic whitish flow in the pulmonary artery.

Temporal Changes of the Calcium-binding Proteins in the Medial Vestibular Nucleus following Unilateral Labyrinthectomy in Rats

홍석민,이재희,박병림,여승근,차장일 대한약리학회 2008 The Korean Journal of Physiology & Pharmacology Vol.12 No.3

Calcium (Ca²+) is an intracellular second messenger associated with neuronal plasticity of the central nervous system. The calcium-binding proteins regulate the Ca²+-mediated signals in the cytoplasm and buffer the calcium concentration. This study examined temporal changes of three calcium-binding proteins (calretinin, calbindin and parvalbumin) in the medial vestibular nucleus (MVN) during vestibular compensation after unilateral labyrinthectomy (UL) in rats. Rats underwent UL, and the changes in the expression of these proteins at 2, 6, 12, 24, 48, and 72 h were examined by immunofluorescence staining. The expression levels of all three proteins increased immediately after UL and returned to the control level by 48 h. However, the level of calretinin showed changes different from the other two proteins, being expressed at significantly higher level in the contralateral MVN than in the ipsilateral MVN 2 h after UL, whereas the other two proteins showed similar expression levels in both the ipsilateral and contralateral MVN. These results suggest that the calcium binding proteins have some protective activity against the increased Ca²+ levels in the MVN. In particular, calretinin might be more responsive to neuronal activity than calbindin or parvalbumin. Calcium (Ca²+) is an intracellular second messenger associated with neuronal plasticity of the central nervous system. The calcium-binding proteins regulate the Ca²+-mediated signals in the cytoplasm and buffer the calcium concentration. This study examined temporal changes of three calcium-binding proteins (calretinin, calbindin and parvalbumin) in the medial vestibular nucleus (MVN) during vestibular compensation after unilateral labyrinthectomy (UL) in rats. Rats underwent UL, and the changes in the expression of these proteins at 2, 6, 12, 24, 48, and 72 h were examined by immunofluorescence staining. The expression levels of all three proteins increased immediately after UL and returned to the control level by 48 h. However, the level of calretinin showed changes different from the other two proteins, being expressed at significantly higher level in the contralateral MVN than in the ipsilateral MVN 2 h after UL, whereas the other two proteins showed similar expression levels in both the ipsilateral and contralateral MVN. These results suggest that the calcium binding proteins have some protective activity against the increased Ca²+ levels in the MVN. In particular, calretinin might be more responsive to neuronal activity than calbindin or parvalbumin.