• Title/Summary/Keyword: 구조적 안정도

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Improvement in $AI_2O_3$ dielectric behavior by using ozone as an oxidant for the atomic layer deposition technique (ALD법으로 제조된 $AI_2O_3$막의 유전적 특성)

  • 김재범;권덕렬;오기영;이종무
    • Journal of the Korean Vacuum Society
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    • v.11 no.3
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    • pp.183-188
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    • 2002
  • In the present study AI$(CH_3)_3)$films were deposited by the ALD technique using trimethylaluminum(TMA) and ozone to improve the quality of the AI$(CH_3)_3)$ films, since the $OH^-$ radicals existing in the AI$(CH_3)_3)$ films deposited using TMA and $H_2O$ degrade the physical and the dielectric properties of the AI$(CH_3)_3)$ film. The XPS analysis results indicate that the $OH^-$ radical concentration in the AI$(CH_3)_3)$film deposited using $O_3$is lower than that using $H_2O$. The etch rate of the AI$(CH_3)_3)$film deposited using $O_3$is also lower than that using $H_2O$, suggesting that the chemical inertness of the former is better than the latter. The MIS capacitor fabricated with the TiN conductor and the $Al_2$O$_3$dielectrics formed using $O_3$offers lower leakage current, better insulating property and smaller flat band voltage shift $({\Delta}V_{FB})$.

Changes in benthic macroinvertebrates communities in response to biological mosquito larvae control techniques (생물학적 모기유충 방제기법 적용에 따른 저서성 대형무척추동물 군집 변동)

  • Han, Jung Soo;An, Chae Hui;Choi, Jun Kil;Lee, Hwang Goo
    • Korean Journal of Environmental Biology
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    • v.37 no.4
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    • pp.600-606
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    • 2019
  • The study site was the camping area in the Hwarang Amusement Park in Danwon-gu, Ansan-si. Study activities were conducted three times a week from July 20, 2018, to August 1, 2018. A control site, natural enemy site, and Bti(Bacillus thuringiensis israelensis) site were selected. The analyses included habitat environment and species composition analyses, community analysis, correlation analysis, and similarity analysis. The water quality analysis found no significant difference in water quality over the study period (p>0.05). A total of 4,818 individuals, 38 species, 22 families, and 11 orders were observed during the study period. The natural enemy site observed during the study period had a similar species composition as the control site. The Bti site differed from other sites by the low number of species and individuals present. According to the community analysis, the natural enemy site was a stable community and the Bti site was an unstable community during the study period. Diptera showed negative associations with temperature and water temperature and mosquito larvae showed significant correlations with temperature and water temperature. The similarity analysis showed that the control site and the natural enemy site were 61.11-73.68% and the Bti site showed 30.77-56.00% similarity.

Development of Value-added Service Application for ESP based on Consumer Portal System (수용가 포탈 시스템 기반의 전력부가서비스 구축 방안 연구)

  • Yang, Won-Chul;Kim, Jae-Hee;Kim, Sang-Soo
    • Proceedings of the Korean Information Science Society Conference
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    • 2006.10d
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    • pp.350-355
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    • 2006
  • 선진 전력시장의 경우, 전력산업의 환경변화에 따라 소비자의 역할이 증대되고 있으며 이와 더불어 IT 기반의 다양한 소비자 중심의 전력부가서비스의 개발이 시도되고 있거나 일부 제공되고 있다. 이러한 서비스의 발전은 시간이 흐르면서 단방향이 아닌 양방향 통신 기반의 소비자 중심 서비스에 대한 연구로 확대되고 있다. 특히, 미국 EPRI의 IntelliGrid 컨소시엄에서 제시한 수용가 포탈 시스템은 소비자 영역내의 장비와 에너지 서비스 기관 간의 양방향 통신을 전제함으로써 이루어지는 통합적인 개념의 서비스 기반으로써, 공급자를 포함한 ESP(Energy Service Provider)와 소비자는 수용가 포탈을 기반으로 원활한 커뮤니케이션을 수행하고 그 결과를 이용한 부가적 이익을 누릴 수 있게 된다. 이에 비해 국내의 전력부가서비스 제공 수준은 이제 겨우 시작 단계에 불과하지만, 서비스에 대한 인식 정도와 IT기술의 발전 속도를 생각해 본다면 머지않아 국내 전력산업에서도 현재의 서비스 제공 수준을 한 단계 넘어선 양방향 통신 기반의 수준 높은 전력부가서비스를 요구하게 될 것이다. 따라서, 국내 환경에 적합한 수용가 포탈 시스템 기반의 전력부가서비스 창출은 수용가에게는 비용 절감이 가능한 합리적인 소비를 제시하고, ESP(Energy Service Provider)에게는 부하·수요관리 및 투자비를 절감할 수 있는 기회를 제공해야 할 것이다. 본 논문에서는 새로운 전력부가서비스 기반인 수용가 포탈시스템을 분석하고, 현행 전력부가서비스의 현황과 동향 분석, 적용가능 기술 분석, 타 산업 벤치마킹을 통해 국내환경에 적합한 수용가 포탈 시스템 기반의 전력부가서비스 선정 및 구축 방안을 제시하고자 한다.원 사용이 가능하도록 설계하였다.서버로 분산처리하게 함으로써 성능에 대한 신뢰성을 향상 시킬 수 있는 Load Balancing System을 제안한다.할 때 가장 효과적인 라우팅 프로토콜이라고 할 수 있다.iRNA 상의 의존관계를 분석할 수 있었다.수안보 등 지역에서 나타난다 이러한 이상대 주변에는 대개 온천이 발달되어 있었거나 새로 개발되어 있는 곳이다. 온천에 이용하고 있는 시추공의 자료는 배제하였으나 온천이응으로 직접적으로 영향을 받지 않은 시추공의 자료는 사용하였다 이러한 온천 주변 지역이라 하더라도 실제는 온천의 pumping 으로 인한 대류현상으로 주변 일대의 온도를 올려놓았기 때문에 비교적 높은 지열류량 값을 보인다. 한편 한반도 남동부 일대는 이번 추가된 자료에 의해 새로운 지열류량 분포 변화가 나타났다 강원 북부 오색온천지역 부근에서 높은 지열류량 분포를 보이며 또한 우리나라 대단층 중의 하나인 양산단층과 같은 방향으로 발달한 밀양단층, 모량단층, 동래단층 등 주변부로 NNE-SSW 방향의 지열류량 이상대가 발달한다. 이것으로 볼 때 지열류량은 지질구조와 무관하지 않음을 파악할 수 있다. 특히 이러한 단층대 주변은 지열수의 순환이 깊은 심도까지 가능하므로 이러한 대류현상으로 지표부근까지 높은 지온 전달이 되어 나타나는 것으로 판단된다.의 안정된 방사성표지효율을 보였다. $^{99m}Tc$-transferrin을 이용한 감염영상을 성공적으로 얻을 수 있었으며, $^{67}Ga$-citrate 영상과 비교하여 더 빠른 시간 안에 우수한 영상을 얻을 수 있었다. 그러므로 $^{99m}Tc$-transierrin이 감염 병소의 영상진단

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Issues and Challenges on the Adaptation of Korean Society for North Korean women defectors -Community Settlement system (탈북여성의 한국사회적응에 대한 쟁점과 과제 - 지역사회 정착제도를 중심으로)

  • Kwon, Sung-Chul
    • Journal of Digital Convergence
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    • v.16 no.10
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    • pp.101-113
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    • 2018
  • This study aims to elucidate the major issues and problems of the North Korean woman defectors focusing on the Community settlement system of Korean society in the time of the historical change of the rapidly changing inter - Korean relations starting from the recent summit talks between North and South Korea. Analytical methods were conducted using literature and previous research data. The results of this study are summarized as follows. The necessity of legal and institutional support reflecting the characteristics of life of North Korean woman defectors and experience of defecting, the necessity of development and management of employment education and employment support program for stable settlement support, the necessity of an integrated support system of public - private cooperation governance structure The need for a tailored social adaptation program tailored to individual needs arises. The results of this study are important to suggest the direction of improvement of the actual system through studying the policy and system of the settlement of Korean society in advance of the unification era. In future research, the support system for the settlement of the South Korean society A variety of studies to identify the factors for role formation will be needed.

Preparation of nanoparticles CuInSe2 absorber layer by a non-vacuum process of low cost cryogenic milling (저가의 cryogenic milling 비진공법을 이용한 나노입자 CuInSe2 광흡수층 제조)

  • Kim, Ki-Hyun;Park, Byung-Ok
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.23 no.2
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    • pp.108-113
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    • 2013
  • Chalcopyrite material $CuInSe_2$ (CIS) is known to be a very prominent absorber layer for high efficiency thin film solar cells. Current interest in the photovoltaic industry is to identify and develop more suitable materials and processes for the fabrication of efficient and cost-effective solar cells. Various processes have been being tried for making a low cost CIS absorber layer, this study obtained the CIS nanoparticles using commercial powder of 6 mm pieces for low cost CIS absorber layer by high frequency ball milling and cryogenic milling. And the CIS absorber layer was prepared by paste coating using milled-CIS nanoparticles in glove box under inert atmosphere. The chalcopyrite $CuInSe_2$ thin films were successfully made after selenization at the substrate temperature of $550^{\circ}C$ in 30 min, CIS solar cell of Al/ZnO/CdS/CIS/Mo structure prepared under various deposition process such as evaporation, sputtering and chemical vapor deposition respectively. Finally, we achieved CIS nanoparticles solar cell of electric efficient 1.74 % of Voc 29 mV, Jsc 35 $mA/cm^2$ FF 17.2 %. The CIS nanoparticles-based absorber layers were characterized by using EDS, XRD and HRSEM.

Research of the local cultural brand by analyzing the case of Honggildong cultual content business strategy (홍길동 문화콘텐츠사업 사례분석을 통한 지역문화 브랜드화 전략 연구)

  • Shim, Jae-Kwang;Lee, Sang-Gil;Kim, Kyoung-Soo
    • Journal of Digital Contents Society
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    • v.11 no.4
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    • pp.479-486
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    • 2010
  • A lot of local governments are trying to develop and brand the regional unique resources as a digital contents because of focusing on the intangible value of it's culture and economy of cultural industry. But every cultual contents business is not always successful. It must be successful on the condition that the cooperation of local government including citizens and private company's participation should make this business a good model of continuous potential growth power. The most important factor of it's business will be the realization of stable plan based on the design of business and carefully throughout plan. The other key factors are the analysis of the objective source and current market demands, the development of contents and story telling. Also the development of strategy of the content including OSMD(One-Source Multi-Device) and OSMU(One-Source Multi-Use) through the step analysis of the result must take into consideration. With the help of analyzing the successful cultural model "Honggildong cultual content business in Jangseong, Jeonnam" which is the representative case of OSMD and OSMU, this study attempts to suggest the successful strategy of regional culture resource brand. In order to provide a typical approach to the local government and cultural content industry which is trying to brand the regional cultual resource, this study researches the analysis of the development of Honggildong cultural resources and it's process step by step which was already finished it's first business stage.

A Multiple Criteria Decision-making Model to Select an Optimal Tomato Export Farm (최적의 토마토 수출 생산자 선정을 위한 다기준 의사결정 모델)

  • Seo, Kwang-Kyu;Kim, Young Shik
    • Journal of Digital Convergence
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    • v.11 no.1
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    • pp.121-127
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    • 2013
  • As the worldwide trade of agricultural products became liberalized with the establishment of WTO and FTA, relatively cheaper agricultural products have influenced the Korean domestic market substantially. Fortunately, foreign countries have soften their restrictions on Korean agricultural exports, providing Korean farmers with more opportunities to advance into the world market. This study aims to propose a multiple-criteria decision-making model for selecting an optimal tomato export farm, as the part of an effort to vitalize exports of domestic agricultural products amid the competitive agricultural market worldwide. For this purpose, we are suggesting a 2-step decision-making model which consists of a simple hierarchy decision model that preliminary selects tomato export farms and a detailed hierarchy decision model that chooses the final and optimal tomato export farm. We applied the analytic hierarchy process (AHP) to determine the relative importance of the used evaluation factors and to choose the tomato export farms with most potential. Eventually, the systematic and efficient decision-making model proposed in this paper can be applied to determine the optimal export farms for crops other than tomato, and thus it can encourage the competitiveness of Korean agricultural exports.

Estimation of design floods for ungauged watersheds using a scaling-based regionalization approach (스케일링 기법 기반의 지역화를 통한 미계측 유역의 설계 홍수량 산정)

  • Kim, Jin-Guk;Kim, Jin-Young;Choi, Hong-Geun;Kwon, Hyun-Han
    • Journal of Korea Water Resources Association
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    • v.51 no.9
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    • pp.769-782
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    • 2018
  • Estimation of design floods is typically required for hydrologic design purpose. Design floods are routinely estimated for water resources planning, safety and risk of the existing water-related structures. However, the hydrologic data, especially streamflow data for the design purposes in South Korea are still very limited, and additionally the length of streamflow data is relatively short compared to the rainfall data. Therefore, this study collected a large number design flood data and watershed characteristics (e.g. area, slope and altitude) from the national river database. We further explored to formulate a scaling approach for the estimation of design flood, which is a function of the watershed characteristics. Then, this study adopted a Hierarchical Bayesian model for evaluating both parameters and their uncertainties in the regionalization approach, which models the hydrologic response of ungauged basins using regression relationships between watershed structure and model. The proposed modeling framework was validated through ungauged watersheds. The proposed approach have better performance in terms of correlation coefficient than the existing approach which is solely based on area as a predictor. Moreover, the proposed approach can provide uncertainty associated with the model parameters to better characterize design floods at ungauged watersheds.

다양한 활성제 이온이 치환 고용된 MgNb2O6 형광체의 특성

  • Kim, Ji-Seon;Jo, Sin-Ho
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.08a
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    • pp.167-167
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    • 2013
  • 최근에 산화물 형광체는 황화물 형광체에 비해 높은 화학적 안정성을 나타내기 때문에 백색 발광 다이오드, 전계방출 디스플레이와 플라즈마 디스플레이 패널에 그 응용성을 넓히고 있다. 마그네슘 니오베이트(magnesium niobate, MgNb2O6)는 우수한 유전 특성(상대 유전상수=18.4)을 나타내기 때문에 마이크로파 유전체로 응용 가능하며, 단일상 릴랙서 페라브스카이트(relaxor perovskite) Pb(Mg1/3Nb2/3)O3을 합성하기 위한 전구체 (precursor)로 널리 사용되고 있으며, 나이오븀산염 이온에서 다양한 색상을 방출하는 활성제 이온으로 효율적인 에너지 전달이 일어남으로써 Sm3+, Dy3+, Eu3+와 같은 희토류 이온의 좋은 모체 격자로 개발할 수 있다. 본 연구에서는 마그네슘 니오베이트 MgNb2O6 모체 결정에 다양한 활성제 이온, 즉 Eu3+, Sm3+, Dy3+, Tb3+를 선택적으로 주입하여 발광 효율이 높은 천연색 형광체를 합성하고자 한다. 특히, 모체 결정에 주입되는 활성제 이온 주위의 국소적인 환경이 반전 대칭에서 변형되는 척도를 조사하여 활성제의 주 발광 파장의 세기가 최대가 되는 최적의 조건을 결정하고자 한다. Mg1-1.5xNb2O6:REx3+ 형광체 분말 시료는 초기 물질 MgO, Nb2O5와 희토류 이온을 화학 반응식에 맞게 정밀 저울로 측량하여 플라스틱 용기에 ZrO2 볼과 함께 넣고, 소정의 에탄올을 채운 뒤 밀봉하고서, 300 rpm의 속도로 20시간 볼밀 (ball-mill) 작업을 수행하였다. 그 후, 체(sieve)로 ZrO2 볼을 걸러낸 다음에 혼합된 용액을 각 비커에 담아서 $40^{\circ}C$의 건조기에서 24시간 건조하였고, 건조된 시료를 막자 사발에 넣고 잘게 갈고 80 ${\mu}m$의 체로 걸러낸 후에, 알루미나 도가니에 활성제 이온별로 각각 담아, 전기로에 장입하여 매분당 $5^{\circ}C$의 비율로 온도를 상승시켜 $350^{\circ}C$에서 5시간 동안 하소 공정을 실시한 후에, 온도를 계속 일정한 율로 증가시켜 $1,200^{\circ}C$에서 5시간 동안 소성하여 합성하였다. 합성된 형광체 분말의 결정 구조는 $Cu-K{\alpha}$ 복사선(파장: 1.5406)을 사용하여 X-선회절장치로 측정하였으며, 형광체의 표면 형상은 전계형 주사전자현미경으로 관측하였다. 흡광와 발광스펙트럼은 제논 램프를 광원으로 갖는 형광 광도계를 사용하여 측정하였다. 모체 결정에 활성제 이온 Eu3+, Sm3+, Dy3+, Tb3+가 도핑된 형광체 분말은 각각 적색, 주황색, 황색, 녹색 발광이 관측되었다. 각 발광 스펙트럼과 결정 입자의 크기와 형상 사이의 상호 관계를 조사하였다. 실험 결과로부터, 각 형광체의 발광 파장은 활성제 이온의 종류 와 서로 밀접하게 관련되어 있으며, 형광체 시료 합성시 활성제 이온의 농도를 선택적으로 조절함으로써 발광의 세기를 제어할 수 있음을 확인하였다.

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Analyses of Larg Cell Area MCFC System Dynamics (대면적 용융탄산염 연료전지 시스템 동특성 분석)

  • 강병삼;고준호;이충곤;임희천
    • Journal of Energy Engineering
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    • v.8 no.4
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    • pp.592-604
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    • 1999
  • The steady state and dynamic characteristics of large cell area MCFC stacks were analyzed to solve the problems such as temperature difference generated in stacks and pressure difference between anode and cathode. Manipulated variables (current density, duel utilization rate, oxidant utilization rate) and controlled variables (temperature difference, anode and cathode pressure difference) which had an important effect on the MCFC stack performance were determined using operation results of two types of MCFC stacks (5kW (3,000 $\textrm{cm}^2$, 20 ea). 3kW (6,000 $\textrm{cm}^2$, 5ea)). The stability and transfer function representing system dynamics were obtained by steady state gain rate which showed the relative change between MVs and CVs. The transfer function was a 3$\times$3 matrix and a typical first order system without time delay. The optimal operating condition of large cell area MCFC stacks could be determined by analyzing dynamic characteristics. In case of a 5 kW MCFC stack, pressurized operation with recycle flow should be used to control the outlet temperature less than 68$0^{\circ}C$ and to control the MCFC system effectively. MIMO control or decoupler should be used to remove the interaction between MVs and CVs. This result will be used as important data in determining the control structure design and operation mode of large cell area MCFC systems in the future.

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