• Title/Summary/Keyword: 논문성과물

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Fabrication of ZrO2 Nano Tube by Atomic Layer Deposition with Exposure Time Control System (전구체 노출 시간을 조절하는 원자층 증착기술에 의한 ZrO2 나노 튜브 제조)

  • Shin, Woong-Chul;Ryu, Sang-Ouk;Seong, Nak-Jin;Yoon, Soon-Gil
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.11a
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    • pp.39-39
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    • 2007
  • 원자층 증착(Atomic Layer Deposition: ALD) 방법은 반응물질들을 펄스형태로 챔버에 공급하여 기판표면에 반응물질의 표면 포화반응에 의한 화학적 흡착과 탈착을 이용한 박막증착기술이다. ALD법은 기존의 화학적 기상증착(Chemical Vapor Deposition: CVD)과 달리 자기 제한적 반응(self-limiting reaction) 에 의하여 반응가스가 기판 표면에서만 반응하고 가스와 가스 간에는 반응하지 않는다. 따라서 박막의 조성 정밀제어가 쉽고, 파티클 발생이 없으며, 대면적의 박막 증착시 균일성이 우수하고, 박막 두께의 정밀 조절이 용이한 장점이 있다. 이러한 ALD 방식으로 3차원의 반도체 장치 구조물에 산화막 등을 형성하는 공정에서 중요한 요소 중의 하나는 전구체의 충분한 공급이다. 따라서 증기압이 높은 전구체를 선호하는 경향이 있다. 그러나 증기압이 낮은 전구체를 사용할 경우, 공급량이 부족하여 단차 도포성(step coverage)이 떨어지는 문제가 있다. 원자층 증착 공정에서 전구체를 충분히 공급하기 위해전구체 온도를 증가시키거나 전구체의 공급시간을 늘리는 방법을 사용한다. 그러나 전구체 온도를 상승시키는 경우, 전구체의 변질이나 수명을 단축시키는 문제점을 발생시킬 수 있으며. 전구체를 충분히 공급하기 위하여 전구체의 공급시간을 늘이는 방법을 사용하면, 원하는 박막을 형성하기 위하여 소요되는 공정시간과 전구체 사용량이 증가된다. 본 논문에서는 이러한 문제점을 해결하기 위해 반응기 안에서 전구체 노출 시간을 조절하는 새로운 ALD 공정을 소개한다. 특히 이러한 기술을 적용하면 나노튜브를 성장시키는데 매우 유리하다. 본 연구에서 전구체 노출 시간을 조절하기 위하여 사용된 ALD 장비는 Lucida-D200-PL (NCD Technology사)이며 (TEMA)Zr와 H2O를 사용하여 ZrO2 나노튜브를 폴리카보네이트 위에 성장시켰다. 전구체의 노출 시간은 반응기의 Stop 밸브를 이용하여 조절하였으며, SEM, TEM 등을 이용하여 나노튜브의 균일성과 단차피복성 등의 특성을 관찰하였다. 그 결과 전구체 노출시간을 조절함으로써 높은 종횡비를 갖는 나노튜브를 성장 시킬 수 있음을 확인하였다. 또한 낮은 증기압을 가지는 전구체를 이용하여도 우수한 특성의 나노튜브를 균일하게 성장시킬 수 있었다.

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Calibration and Validation of SWAT Model for Long Term Simulation of Runoff and Sediment Transport at the Nakdong River Basin (낙동강유역의 장기 유역 유출 및 유사 모의를 위한 SWAT 모형의 검보정)

  • Lee, Eun-Jung;Jang, Eun-Kyung;Kim, Tae-Keun;Hwang, Man-Ha;Kwon, Yong-Sung
    • Proceedings of the Korea Water Resources Association Conference
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    • 2012.05a
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    • pp.881-881
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    • 2012
  • 낙동강유역에는 4대강 사업으로 8개의 보가 낙동강 본류에 새롭게 설치되었으며, 따라서 상류로부터 유입되는 유사가 보상류에 퇴적되어 하천제방이나 하천구조물의 안전을 위협할 수 있다. 또한 홍수시에는 농경지의 매몰과 저수지의 퇴적현상이 발생하는 등 유역유사에 의한 다양한 문제가 발생할 수 있으며, 강우로부터 유출되는 유사는 강우사상에 따라 빠르게 변할 수 있으나 수체에 즉각적인 영향을 유발하지 않을 경우 만성적인 특성으로 인해 침전물을 계속 이동시키며 축적되는 문제가 발생한다. 따라서 이러한 문제를 사전에 예측하고 낙동강유역에 대한 유역유사관리 대책마련을 마련하기 위해 유역유출과 유사의 이송 및 퇴적양상을 분석하여 유역관리를 위한 자료를 구축할 필요가 있다. 이러한 기초자료 분석을 위해 활용되는 유역모형 중 SWAT(Soil and Water Assessment Tool) 모형은 장기간 유역 유출로 인한 유사 모의를 수행하는데 가장 많이 활용되는 모형이며, 미국 농무성 농업연구소(USDA Agricultural Research Service, ARS)의 Jeff Amold 등에 의해 개발된 모형이다. SWAT 모형은 장기유출 및 유사 발생에 대한 시 공간적 변화를 모의하는 모형으로 넓은 범위의 유역에 대해 일단위 모의 간격으로 최대 100년까지 모의가 가능한 장기유역 모의에 최적화된 모형이다. 본 논문에서는 SWAT 모형을 이용하여 낙동강유역의 장기 유역 유출 및 유사 모의를 수행하기위해 2004년에서 2009년까지의 유출량 자료와 유량-유사량관계곡선 등을 이용하여 본류 및 지류 유출구 주요지점에 대해 검보정을 수행하고자 한다. 모의의 정확도 향상을 위해 안동댐, 임하댐, 영천댐, 합천댐, 남강댐, 밀양댐 및 낙동강 본류 등 총 7개 유역으로 구분하여 SWAT 모형을 구축하였으며, 각 유역별로 유출량과 유사량에 대하여 각각 보정 및 검증을 수행하였다. 낙동강 본류유역 총 7개의 댐 방류량자료와 20개의 대형하수종말처리장 방류량자료를 이용한 낙동강유역의 유출량 보정 및 검증 결과, 모의치가 실측치를 잘 반영하고 있는 것으로 나타났다. 또한 총 11개 지점의 수위관측소에 대해 유사량 측정 성과를 이용한 유사량 보정 및 검증 결과, 강우시 유사량 모의값은 유출량-유사량관계곡선 식을 잘 반영하였으나, 비강우시에는 모의값이 관계곡선 식의 결과값보다 대체적으로 높게 나타났다.

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The Influence of the Environmental Conditions, the Political Tendency and the Degree of Freedom during Performance on the Perception of Journalists on the Quality of the Press (뉴스생산 환경 및 조직과 기자의 정치적 성향, 업무 수행 자유도가 언론의 전문성, 공정성 인식에 미치는 영향 연구)

  • Hong, Ju-Hyun;Choi, SunYoung
    • The Journal of the Korea Contents Association
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    • v.17 no.5
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    • pp.209-220
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    • 2017
  • This study explores what are the factors which influence the perception of press professionalism and fairness of journalist in the process of their news production. This study focused on how the difference between mainstream media and online media, the political tendency and the degree of freedom during working effected on the judgement of the freedom of press based on the model of Shoemaker and Reese' hierarchical model. As a result, Research finding is as follows: First, online media journalist evaluated the fairness of press higher than offline media journalists. Second, the consistency of political tendency of offline media is different from online media. Online media journalists evaluated the fairness of the press higher than offline media journalists. Finally, the degree of freedom during performance is the most importance factor which affects the evaluation of press fairness. This study highlights the factors which influence the perception of journalists on the quality of the press based on the survey data which have conducted by Korean press foundation This study implicates how working environment is importance in journalist's writing as a journalist. The freedom of press is very important in the process of news production because the factors which influence the evaluation of the fairness and the professionalism of press reveals the quality of press.

The Factors Affecting Technology Commercialization of Government Research Institutes: The Case of Research Institute Spin-offs (출연(연)의 기술사업화에 미치는 요인 분석 -연구소기업을 중심으로-)

  • Jung, Hye-Jin
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.9
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    • pp.74-82
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    • 2016
  • The term research institute spin-offs refers to new firms created by public research institutes. These spin-offs are different from other start-ups in two respects: on the one hand, they should be located in the Special Research and Development Zones and, on the other hand, these firms are supposed to commercialize the results of public R&D activities. These spin-off firms show higher rates of survival and job creation than general new firms, which means that their contribution to economic growth is not negligible. The present study analyzes the factors affecting research institute spin-offs using a random effect panel logit model and negative binomial model. From previous studies, four elements are identified as playing an important role in the commercialization of public R&D through spin-offs, namely their organizational character, research capability, technological character, and geographical location. The empirical results demonstrate that government research institutes with more researchers and patents are more likely to create new firms. In addition, the location of the institutes significantly affects the probability of their creating spin-offs and their number. When the technological stage and TLO size are considered, however, it turns out that the number of researchers and technological stage play important roles in the spin-offs.

Evaluation Factor and Enhancement of Gwangyang International Port's Competitiveness (광양항의 경쟁력 평가요인과 강화전략)

  • Jeong, Bonghyun
    • Journal of Korea Port Economic Association
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    • v.30 no.1
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    • pp.119-142
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    • 2014
  • This study aims to evaluate the factors which affect the competitiveness of Gwangyang port, and to suggest strategies for the enhancement of its competitiveness by priority. This study inquires both 5 key rating factors: port location, port operations management, port costs, port facilities, and hinterland conditions and the priority of 14 detailed assessments through AHP method. First, the importances of main evaluation items for port competitiveness are analysed in the following orders: port location, port facilities, port costs, port operations, hinterland conditions. Second, the comprehensive importances based on the detailed evaluation properties complex weighting are identified in the following orders: connectivity with hinterland, accessibility of international harbor, incentives, the area of terminal, expertise and skills of port operations personnel, container throughput, and scale berths. Third, the strategies referring to the port location like centrality, transit, and merit on use should be actively conducted for the promotions of Gwangyang port's competitiveness, according to its international port competitiveness analysis. This study will provide both academic and policy implications with its related scholars, government, and research institutions. In addition, this will be contributed to formulating a basic theory for port competitiveness evaluation and providing a basic framework of evaluation analysis.

A Study on Enclosed Mast Characteristics for Radar Cross-Section Reduction (레이더반사면적 감소를 위한 폐위형 마스트 특성 연구)

  • Kwon, Hyun-Wung;Hong, Suk-Yoon;Hwang, Joon-Tae;Jeong, Seung-Jin;Kim, Jong-Chul;Song, Jee-Hun
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.23 no.6
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    • pp.746-753
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    • 2017
  • Radar Cross Section (RCS) is a factor directly related to survivability, and a design to reduce the presence of this factor is needed. The upper structure, guns, radar and so on are related to warship RCS, but radar RCS reduction is difficult because of complex shapes involved. In this paper, an enclosed mast, which is one modern method for reducing radar RCS, and the characteristics of an applied Frequency Selected Surface (FSS) are analyzed. The RCS reduction ability of an enclosed mast has been confirmed by comparing RCS analysis results for a general radar with that of an enclosed mast for available frequency according to FSS shape. The characteristics of the enclosed mast have also been studied by analyzing the elevation angle and slope of the mast. General radar RCS was high because of its complex shape, but low RCS was shown for the enclosed mast model, which had a simpler shape.

Numerical Analysis of Riverbed Changes at the Downstream of the Ji-Cheon (수치모형을 이용한 지천하류부의 하상변동 분석)

  • Choi, Ho;Rim, Chang-Soo;Jung, Jae-Wook
    • Journal of the Korean Society of Hazard Mitigation
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    • v.11 no.3
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    • pp.117-125
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    • 2011
  • River bed variation drops storage capacity of dams and reservoirs, and furthermore deteriorates safety of banks and peers. Therefore, understanding of bed variation is important to use and manage river water. Study section is downstream part of Ji- Cheon nearby Ji-Cheon Bridge which is located in Gum river basin. The river surveying at fourteen places with the length of 1,320m were undertaken on November 7, 2003 and September 24, 2004, and the results of river surveying were analyzed for the study. Real bed variation was compared with the simulation results of HEC-6 and GSTARS 3.0. Cross section data for the simulation of HEC-6 and GSTARS3.0 were composed of the basis of river surveying data on November 7, 2003. Hydrological data were acquired from Gu-Ryong watermark located at Ji-Chun Bridge. The research results revealed that when using Toffaleti equation, simulation results of two models were similar to the real bed variation. The bed variation simulated by using GSRARS 3.0 with only one stream tube was similar to the real bed variation. The bed variation simulated by using two models(HEC-6 and GSTRARS 3.0) with Toffaleti equation was also similar to the real bed variation. Therefore, it is expected that HEC-6 and GSTARS 3.0 models have applicability to predict the bed variation at the downstream of Ji-Cheon.

In-Plane Extensional Vibration Analysis of Asymmetric Curved Beams with Linearly Varying Cross-Section Using DQM (미분구적법(DQM)을 이용한 단면적이 선형적으로 변하는 비대칭 곡선보의 내평면 신장 진동해석)

  • Kang, Ki-Jun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.5
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    • pp.612-620
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    • 2019
  • The increasing use of curved beams in buildings, vehicles, ships, and aircraft has results in considerable effort being directed toward developing an accurate method for analyzing the dynamic behavior of such structures. The stability behavior of elastic curved beams has been the subject of a large number of investigations. Solutions of the relevant differential equations have traditionally been obtained by the standard finite difference. These techniques require a great deal of computer time as the number of discrete nodes becomes relatively large under conditions of complex geometry and loading. One of the efficient procedures for the solution of partial differential equations is the method of differential quadrature. The differential quadrature method(DQM) has been applied to a large number of cases to overcome the difficulties of the complex algorithms of programming for the computer, as well as excessive use of storage due to conditions of complex geometry and loading. In this study, the in-plane extensional vibration for asymmetric curved beams with linearly varying cross-section is analyzed using the DQM. Fundamental frequency parameters are calculated for the member with various parameter ratios, boundary conditions, and opening angles. The results are compared with the result by other methods for cases in which they are available. According to the analysis of the solutions, the DQM, used only a limited number of grid points, gives results which agree very well with the exact ones.

A Study on Methods for the Domestic Diffusion of Intelligent Security Project : With a Focus on the Case of Smart City Integrated Platform (지능형 방범 사업의 국내 확산 방안 연구 : 스마트시티 통합플랫폼을 대상으로)

  • Shin, Young-Seob;Han, Sun-Hee;Lee, Jae-Yong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.7
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    • pp.474-484
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    • 2019
  • In this age, where the social environment is changing rapidly and unpredictably, interest in safety from crime is increasing in Korean society. As the desire to live a life free from the fear of crime increases, interest in the construction of safe cities is also rising nationwide. To meet the national demand, the Korean government is promoting a project to link public disaster safety systems by involving municipalities, 112, 119, and other emergency services and institutions through the Smart City Integrated Platform in order to construct a smart safety net. This study investigates the linking of theSmart City Integrated Platform and theIntelligent Security Project. The results are as follows. 1. The linkage's objective is clear. 2. The system sector can provide information to accident-related organizations. 3. The scenario area can be expanded to a crime-prevention sector, and a long-term urban information integration infrastructure can be created. 4. Product testing is enabled by a smart city road map and through continuous consultation with relevant organizations. 5. Project diffusion to other local governments can be promoted with the continued addition of commercial products.

Reviewing connectionism as a theory of artificial intelligence: how connectionism causally explains systematicity (인공지능의 이론으로서 연결주의에 대한 재평가: 체계성 문제에 대한 연결주의의 인과적 설명의 가능성)

  • Kim, Joonsung
    • Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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    • v.9 no.8
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    • pp.783-790
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    • 2019
  • Cognitive science attempts to explain human intelligence on the basis of success of artificial neural network, which is called connectionism. The neural network, e.g., deep learning, seemingly promises connectionism to go beyond what it is. But those(Fodor & Pylyshyn, Fodor, & McLaughlin) who advocate classical computationalism, or symbolism claim that connectionism must fail since it cannot represent the relation between human thoughts and human language. The neural network lacks systematicity, so any output of neural network is at best association or accidental combination of data plugged in input units. In this paper, I first introduce structure of artificial neural network and what connectionism amounts to. Second, I shed light on the problem of systematicity the classical computationalists pose for the connectionists. Third, I briefly introduce how those who advocate connectionism respond to the criticism while noticing Smolensky's theory of vector product. Finally, I examine the debate of computationalism and connectionism on systematicity, and show how the problem of systematicity contributes to the development of connectionism and computationalism both.