• Title/Summary/Keyword: II-VI

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UV emission characterization of ZnO thin films depending on the variation of oxygen pressure (분위기 산소압변화에 따른 ZnO박막의 UV발광 특성분석)

  • Bae, Sang-Hyuck;Lee, Sang-Yeol
    • Proceedings of the KIEE Conference
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    • 1999.07d
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    • pp.1523-1525
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    • 1999
  • ZnO is a wide-bandgap II-VI semiconductor and has a variety of potential application. ZnO exhibits good piezoelectric, photoelectric and optic properties, and is good for a electroluminescence device. ZnO films have been deposited at (0001) shappire by PLD technique. Chamber was evacuated by turbomolecular pump to a base pressure of $1{\times}10^{-6}$ Torr Nd:YAG pulsed laser was operated at ${\lambda}=355nm$. The ZnO films were deposited at oxygen pressures from base to 500 mTorr. The substrate temperatures was increased from $200^{\circ}C$ to $700^{\circ}C$. At aleady works, UV emission and green-yellow PL was observed. In this work, ZnO films showed UV, violet, green and yellow emissions. UV emission was enhanced by increasing partial oxygen pressure. We investigated relationship between partial oxygen pressure and UV emission.

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A Study on The United States Secret Service (미국 대통령경호제도에 관한 고찰)

  • Jang, Ki-Boong
    • Korean Security Journal
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    • no.4
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    • pp.299-317
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    • 2001
  • The United States Secret Service is the strongest presidential protective organization in the world. Almost every country's security organization in the world is benchmarking its organization, protective operation system, security equipments and etc. In this paper, I study largely on the protective operation system of the U.S Secret Chapter I is the introduction part. Chapter II introduces the establishment and the background of its development of the U.S Secret Service. Chapter III deals with the organization and ranking system of the U.S SS. Chapter IV consider the protective operation system of the 5.5. The main theory of the protective operation is the 'Protective Envelope Philosophy' which emphasizes the "Cover and Evacuate". Also the protective operation system is developed with the principle of the democracy and in the history of continuing assassination attempt against president. Chapter V describes the legal basis and missions of the S.S. Every protective operational mission of the U.S SS is peformed by the legal basis and democratic procedure. It is followed by concluding observation made in Chapter VI.

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A Study on the Plan of Construction of Cooperating Crime Prevention System between Public Police and Private Security of Korea (공경비와 민간경비의 협력방범체제 구축방안)

  • Lee, Sang-Won
    • Korean Security Journal
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    • no.6
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    • pp.67-101
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    • 2003
  • This study presents a plan of construction for cooperating crime prevention system between public police and private security to provide positive safety, and crime prevention activity for clients. A method of this study, this paper used statistics analysis and literature study. This study, an introduction is at the chapter I , a role of public police and private security at the Chapter II, the realities of private security industry of korea at the Chapter III, the police service relating with private security and operating realities at the ChapterIV, the problems and a plan of construction for co-operating crime prevention system at the ChapterV, and conclusion at the ChapterVI. In conclusion, It is needed a public information strategy, partnership between the police and guard, establishment of special office for private security, and the improvement of the quality in security corporation.

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Annular Constrictive Pericarditis: Simulating Vavular Heart Disease : Case Report (윤상 교약성 심낭염의 외과적 치료 -2예 보고-)

  • 유회성
    • Journal of Chest Surgery
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    • v.13 no.3
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    • pp.280-284
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    • 1980
  • This is report of two cases of annular constrictive pericarditis. Since January 1959 to December 1979 the authors experienced 48 cases of chronic constrictive pericarditis treated surgically at the Department of Thoracic and Cardiovascular Surgery, the National Medical Center in Seoul. These cases simulated valvular heart disease. One case, as mitral stenosis, revealed rumbling apical diastolic murmur [II/VI], atrial fibrillation and right ventricular hypertrophy pattern on E.C.G., the other, as infundibular pulmonic stenosis, presented pressure gradient between right ventricle and main pulmonary artery at infundibular level of 76 mmHg in systole. Both patients underwent operation successfully and one of them was assisted by E.C.C. during pericardiectomy and result was excellent. It is difficult to make the diagnosis of these conditions preoperatively so consideration about these might be important to make the diagnosis accurately.

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Technique of Tension Length Calculation for 350km/h High Speed Catenary System (최고운행속도 350km/h급 전차선로 장력구간길이 계산 기법)

  • Chang, Sang-Hoon;Lee, Ki-Won;Kwon, Sam-Young;Park, Jae-Woong
    • Proceedings of the KSR Conference
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    • 2011.05a
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    • pp.932-939
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    • 2011
  • This paper deal with technique of tension length calculation for 350km/h high speed catenary system. Tension length affects in facility investment. Possibility of overlap increasing a tension length and the equipment investor decreases in order to decrease. Considers the parameter which specifies and the grudge which is possible long the fact that decides a tension length is the aim which is important plans overhead contact line. The element which decides a tension length with next following; (i) Operating range of tension device, (ii) Change of the horizontal tension which affects possibility of the effect which operates to the line and span, (iii) Tension of wire material the tensile force which is relation, (iv) Wire thermal expantion which relates with a standard temperature, (v) Curve radius, (vi) Wind velocity, (vii) Thermal range of overhead contact wire and mechanical design of tension mechanism etc.

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A Study on the Adsorption of Metal Ions Utilizing OenNtn Synthetic Resin (OenNtn 합성수지를 이용한 금속이온들의 흡착에 관한 연구)

  • 김준태;노기환
    • Journal of environmental and Sanitary engineering
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    • v.14 no.3
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    • pp.80-89
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    • 1999
  • The ion exchange resins have been synthesized from chlormethyl styrene-1,4-divinyl benzene(DVB) with 1%, 5%, and 10%-crosslinking and macrocyclic ligand of cryptand type by copolymerization method and the adsorption characteristics of uranium(VI), lead(II) and holmium(III) ions have been investigated in various experimental conditions. The correlation between the adsorption characteristics of rare earths and transition metal on the resins and stability constants of complexes with macrocyclic ligand have been examined. The $UO_2^{2+}$ aqueous solutions are not adsorbed on the resins below pH 3.0, but the power of adsorption of $UO_2^{2+}$ increased rapidly above pH 4.0. The adsorption power was in the order of 1%, 10%, and 5%-crosslinked resin, but adsorptive characteristics of resins decreased in proportion to the order of dielectric constants of solvents.

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Seminiferous Epithelium Cycle of Crocidura shantungensis

  • Jeong Seung-Don;Lee Jung-Hun
    • Biomedical Science Letters
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    • v.11 no.4
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    • pp.545-553
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    • 2005
  • The present study provides descriptions of the cellular associations of the seminiferous epithelium cycle in the Crocidura shantungensis. The cycle of the seminiferous epithelium was divided into 14 stages, and developing spermatids were subdivided into 15 steps. The Golgi phase occurs the first two steps, and the cap phase had the next four consecutive steps. The acrosomal and maturation phases were consisted of steps $7\~14$, and the remaining one step consisted the spermiation phase. The Ad type of spermatogonia was observed whole stages, and Ap, In and B spermatogonia were observed from stage II to stage VI. The preleptotene, leptotene and zygotene of primary spermatocytes were observed from VII to XIV stages, and pachytene spermatocyte was observed from I to XII stages. The diplotene spermatocyte was observed XIII stages, and meiotic figures and secondary spermatocytes were observed stage XIV. Our results provide the foundation for a variety of future studies of the spermiogenesis of C. shantungensis.

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The Static and Dynamic Growth Patterns of High-Tech Ventures in Korea

  • Park, Sangmoon;Bae, Zong-Tae
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2001.10a
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    • pp.233-236
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    • 2001
  • This study explores on the static and dynamic growth patterns of high-tech ventures in Korea. We developed an integrative framework with target market (local vs. global), product/market maturity (existing vs. emerging), and technological capability (follower vs. pioneer). We also identified seven new ventures strategies as follows: i) reactive imitation, ii) proactive localization, iii) import substitution, iv) creative imitation, v) early market-entry, vi) global niche, and vii) global innovation. With five successful Korean new ventures, we found different competitive behaviors and performance among new venture strategic types. This study also observed two different growth patterns: growth through strategic replication and growth through strategic change. It depends on whether they are pursuing similar strategy over time or different strategy within for growth. In addition, we found that creative imitation plays a stepping-stone role in two-step internationalization processes. Although this study is exploratory and needs more empirical studies, it can provide new ventures with meaningful guidelines for growth and internationalization with a dynamic perspective.

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II. 윤활기유 공정 및 제품소개

  • 이두원
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 1986.06a
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    • pp.10-20
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    • 1986
  • I. 윤활기유 제조시설소개 개요 1) 고급 윤활기유(HVI)생산공장으로서 그간 수입에만 의존하던 최고급 품질의 기유를 국내 수요업체에 안정공급 2) 세계 최신 공정인 Gulf Lube Oil Hydrotreating Process Type III (수소첨가 개질공정)채택 3) 국내 최초일뿐 아니라, 세계에서도 일본, 카낟에 이어 3번째로 건설 1. 고품질 제품 생산-고점도 지수, 산화안정성 및 열안정성 우수, 잔류탄소분, 윤황분, 질소분 극소, 방향족 성분 및 회분 극소, 색상 양호 2. 첨가제(특히 산화방지제 및 점도 지수 향상제)사용효과 상승으로 완제품 생산시 생산비 감소 3. 동일 VI 제품 생산기준 수율이 높음 - Hydrocarbon Structure 변화로 원료 유중 부적합성분의 윤활기유화 4. Severity 조절로 Production Mode 변경 용이 5. 양질의 부산물 생산 - HDT Naphtha, Middle distillate 6. 용제 추출기유는 원유종류 및 성상에 따라 제품특성이 결정되나, 사용가능 원유가 다양 하면서도 제품특성 및 품질이 일정함.

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A Study on the Policy Directions to Sustainable Rural Development (논문 - 지속가능한 농어촌 지역개발을 위한 정책 방향 연구)

  • Im, Sang-Bong;Chung, Hae-Chang
    • KCID journal
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    • v.18 no.2
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    • pp.101-110
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    • 2011
  • There are found rare specific alternatives for sustainable rural development although sustainable development has become popular common concept in international development arena. Korea is trying to reform rural development by introducing a block grants system since 2009 expecting for the efficiency of development investment. However, it seems that such new rural development system is far from realizing the sustainable development. The objectives of the study are to identify the roles and issues of the sustainable development policy and to suggest a policy model for realizing sustainable rural development. Based on the policy model hypothetically established, some policy alternatives were suggested: (i) the establishment of land use system considering sustainability perspectives; (ii) the preparation of environment management measures considering topographical traits; (iii) the improvement of landscape support scheme toward increasing biodiversity; (iv) the systematic implementation of agriculture-environment measures; (v) the implementation of sustainable development projects linking production to housing; (vi) the inclusion of sustainability indicators in rural development evaluation system.

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