• Title/Summary/Keyword: 퍼지

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Self-Limiting Growth of ZnO Thin Films and Substrate-Temperature Effects on Film Properties (자기제한적 표면반응에 의한 ZnO 박막성장 및 기판온도에 따른 박막특성)

  • Lee, D.H.;Kwon, S.R.;Lee, S.K.;Noh, S.J.
    • Journal of the Korean Vacuum Society
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    • v.18 no.4
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    • pp.296-301
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    • 2009
  • An inductively coupled plasma assisted atomic layer deposition(ICP-ALD) system has been constructed for the deposition of ZnO thin films, and various experiments of ZnO thin films on p-type Si(100) substrates have been carried out to find the self-limiting reaction conditions for the ICP-ALD system under non-plasma circumstances. Diethyl zinc[$Zn(C_2H_5)_2$, DEZn] was used as the zinc precursor, $H_2O$ as the oxidant, and Ar as the carrier and purge gas. At the substrate temperature of $150^{\circ}C$, atomic layer deposition conditions based on self-limiting surface reaction were successfully obtained by series of experiments through the variation of exposure times for DEZn, $H_2O$, and Ar. ZnO deposition was repeated at different substrate temperatures of $90{\sim}210^{\circ}C$. As a result, the thermal process window(ALD window) for ZnO thin films was observed to be $110{\sim}190^{\circ}C$ and the average growth rate was measured to be constant of 0.29 nm/cycle. Properties of the film's microstructure and composition(Zn, O, etc.) were also studied. As the substrate temperature increases, the crystallinity was improved and ZnO(002) peak became dominant. The films deposited at all temperatures were high purity, and the films deposited at high temperatures had the composition ratio between Zn and O closer to one of a stable hexagonal wurtzite structure.

Analysis of Performance Determinants of ODA in Technical and Vocational Education and Training (직업능력개발 ODA사업의 성과 결정요인 분석)

  • Lee, Sang-Chul;Ghang, Bong-Jun;Lee, Jae-Won
    • The Journal of the Korea Contents Association
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    • v.17 no.5
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    • pp.499-508
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    • 2017
  • For analyzing the performance determinants of ODA projects in a technical and vocational education and training, this research analyzed the performance determinants of effectiveness representing the direct benefit and impact representing the long-term development effects of ODA project using FsQCA. As a result, the effectiveness of ODA project is achieved when relevance, sustainability and impact are high, or relevance, impact and efficiency are high. The impact of ODA project is achieved when relevance, sustainability and effectiveness are high, or relevance, effectiveness and efficiency are high. Two solutions for achieving effectiveness and two solutions for achieving impact show equifinality. The core factors for achieving effectiveness are relevance and impact, and the core factors for achieving impact are relevance and effectiveness. Also sustainability and efficiency are substitutability. A single causal variable can not have an effect on the ODA performance, but combined more than three causal variables can have an effect on the ODA performance. Therefore this research verified that collectives of causal variables rather than single causal variable should be considered to achieve the performance of ODA project in technical and vocational education and training.

Segmentation of Multispectral MRI Using Fuzzy Clustering (퍼지 클러스터링을 이용한 다중 스펙트럼 자기공명영상의 분할)

  • 윤옥경;김현순;곽동민;김범수;김동휘;변우목;박길흠
    • Journal of Biomedical Engineering Research
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    • v.21 no.4
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    • pp.333-338
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    • 2000
  • In this paper, an automated segmentation algorithm is proposed for MR brain images using T1-weighted, T2-weighted, and PD images complementarily. The proposed segmentation algorithm is composed of 3 step. In the first step, cerebrum images are extracted by putting a cerebrum mask upon the three input images. In the second step, outstanding clusters that represent inner tissues of the cerebrum are chosen among 3-dimensional(3D) clusters. 3D clusters are determined by intersecting densely distributed parts of 2D histogram in the 3D space formed with three optimal scale images. Optimal scale image is made up of applying scale space filtering to each 2D histogram and searching graph structure. Optimal scale image best describes the shape of densely distributed parts of pixels in 2D histogram and searching graph structure. Optimal scale image best describes the shape of densely distributed parts of pixels in 2D histogram. In the final step, cerebrum images are segmented using FCM algorithm with its initial centroid value as the outstanding clusters centroid value. The proposed cluster's centroid accurately. And also can get better segmentation results from the proposed segmentation algorithm with multi spectral analysis than the method of single spectral analysis.

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Accuracy Improvement of Laser Navigation System using FIS and Reliability (FIS와 신뢰도를 이용한 레이저 내비게이션의 정밀도 향상)

  • Jung, Eun-Kook;Kim, Jung-Min;Jung, Kyung-Hoon;Kim, Sung-Shin
    • Journal of the Korean Institute of Intelligent Systems
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    • v.21 no.3
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    • pp.383-388
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    • 2011
  • This paper presents to study the accuracy improvement of the laser navigation using FIS(fuzzy inference system) and the reliability. As wireless guidance system, the top-mounted laser with the laser navigation can rotate $360^{\circ}$ with phototransistor or other optical sensors that read the return signal from reflectors mounted at the perimeter of the workspace. The type of major existing guidance systems is a wire guidance system. Because they have high accuracy and fast response time, they are used to most industries. However, their installation cost is very expensive and maintenance is very difficult because their sensors are placed approximately 1 inch below the ground or embedded in the floor. To solve those problems, the laser navigation was developed as a wire guidance system. It does not need to reconstruct a floor or ground. And it can reduce costs of installation and maintenance because changing the layout is easy. However, it is difficult to apply to an industrial field because it is easily affected by disturbances which cause loss and damage of data, and has slow respond time. Therefore, we study the accuracy improvement of the laser navigation. The proposed method is a correction method using reliability of the laser navigation. here, reliability is calculated by FIS which is designed with the analyzed characteristics of the laser navigation. For performance comparison, we use original position data form the laser navigation and position data corrected by original reliability from the laser navigation. In experimental result, we verified that the performance of the proposed method compared the others is improved by about 50% or more.

A Study on the Investment Determinants for Residential Real Estate Development by Investor Perspectives (주거용 부동산 개발을 위한 투자자 관점에 따른 의사결정 요인에 관한 연구)

  • Kwon, Jaehong;Lee, Jaewon;Lee, Sangyoub
    • Korean Journal of Construction Engineering and Management
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    • v.21 no.5
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    • pp.29-37
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    • 2020
  • This study analyzed the importance of factors according to the investor's perspective through a survey of residential real estate experts using AHP and fuzzy theory. Analysis results showed that rent, profitability, traffic accessibility, commercial and infrastructure, and financial regulation are important in common. By expert group, financial and credit groups cited profitability, rent, traffic accessibility, supply and tax benefits, construction and development groups cited traffic accessibility, rent, direct access, profitability, commercial area and infrastructure, and appraisal and evaluation groups cited rent, profitability, transportation accessibility, financial regulation and supply as the most important factors. This showed that it had a preference characteristic that was associated with work. In other words, it focuses most on the financial perspective in investment characteristics, and it values convenience such as accessibility to transportation and commercial districts and infrastructure as its location characteristics. In addition, it was found that easing financial regulations in the market is important to expand investment in real estate. This study aims to help the business feasibility analysis of residential property developers and rational decision-making of general investors who are consumers, taking into account the various perspectives of the expert group.

A Study on the GIS-based Deterministic MCDA Techniques for Evaluating the Flood Damage Reduction Alternatives (확정론적 다중의사결정기법을 이용한 최적 홍수저감대책 선정 기법 연구)

  • Lim, Kwang-Suop;Kim, Joo-Cheol;Hwang, Eui-Ho;Lee, Sang-Uk
    • Journal of Korea Water Resources Association
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    • v.44 no.12
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    • pp.1015-1029
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    • 2011
  • Conventional MCDA techniques have been used in the field of water resources in the past. A GIS can offer an effective spatial data-handling tool that can enhance water resources modeling through interfaces with sophisticated models. However, GIS systems have a limited capability as far as the analysis of the value structure is concerned. The MCDA techniques provide the tools for aggregating the geographical data and the decision maker's preferences into a one-dimensional value for analyzing alternative decisions. In other words, the MCDA allows multiple criteria to be used in deciding upon the best alternatives. The combination of GIS and MCDA capabilities is of critical importance in spatial multi-criteria analysis. The advantage of having spatial data is that it allows the consideration of the unique characteristics at every point. The purpose of this study is to identify, review, and evaluate the performance of a number of conventional MCDA techniques for integration with GIS. Even though there are a number of techniques which have been applied in many fields, this study will only consider the techniques that have been applied in floodplain decision-making problems. Two different methods for multi-criteria evaluation were selected to be integrated with GIS. These two algorithms are Compromise Programming (CP), Spatial Compromise Programming (SCP). The target region for a demonstration application of the methodology was the Suyoung River Basin in Korea.

Comparative Discussion of Intercultural Discourses in the 20th Century (20세기 '상호문화 담론들'에 대한 비교 고찰)

  • Jang, Han-Up
    • Korean Journal of Comparative Education
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    • v.28 no.3
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    • pp.265-289
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    • 2018
  • The word culture itself is very difficult to define. Therefore, in order to confine its meaning, many scholars prefer to attach different prefixes such as inter-, bi-, multi-, cross-, pluri-, trans-, in front of the adjective cultural instead of defining the word culture itself. These prefixes have been used along with about thirty various nouns, ranging from adaptability to training. In this paper, we focused on the adjective intercultural. In fact, this adjective has been widely used, not only in education but also in the communication and philosophy sectors among the world academia discourse. Intercultural Education appeared in America in the 1930s and also in the 1970s in Europe, in order to improve relations between immigrants and the people who received them. Intercultural communication arose in America as a cultural education program for American diplomats and professionals, while interculturalism appeared in the 1970s in Canada as a policy in opposition to multiculturalism. Intercultural philosophy started in 1990s Germany as philosophical speculation against Eurocentrism. As such, the adjective intercultural has been used with a combination of diverse nouns. In regards to this, one can ask the following questions: did the scholars have any kind of agreement during their discussions? Did they communicate and make a positive impact on each other? If not, how can we interpret their common use of the word intercultural? To answer these questions, we tried to compare fives types of intercultural waves of the 20th century, paying particular attention to their time periods, places and backgrounds of appearance, their emphases and shortcomings. Following our research, we found that intercultural waves in the 20th Century have developed independently despite their common use of the word intercultural. Therefore, we concluded that the use of same word intercultural was the result of humankind's effort to approach cultural differences in a positive way in the global village created by internationalization and globalization of the 20th century.

A Study on Trade Barriers Analysis in the Chinese Audiovisual Service Sectors (중국 시청각서비스분야 통상장벽 분석과 진출 전략 : AHP와 Fuzzy 신뢰도 지수를 이용하여)

  • Jung, Sang-Chul;Rhee, Hae-Chun
    • Review of Culture and Economy
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    • v.17 no.2
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    • pp.63-80
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    • 2014
  • This study evaluates the importance of negotiation agendas and the possibility of reaching the Korea-China FTA agreement. It assesses the current situation of trade barriers in the audiovisual service sector of China and then examines a survey of practitioners and experts to screen important regulations. The results are as follows: First, considering the national economic situation in Korea and the environment of the Chinese trade barrier, an important agenda is to enable the direct service of online games and to reach a co-production agreement in the audiovisual service sector. Second, an agenda regarding the co-production agreement of an audio-visual service sector has high potential to be realized, followed by agendas regarding online game and music services. In the broadcasting and film service sectors, with their high cultural identity, a mutual cooperative approach is needed. Korea bringing up the agenda regarding online service may allow it to gain a net benefit for the next FATs. To realize a mutual cooperative approach, it is necessary to form a frame of mutual interests and cooperation through a co-production agreement of audio-visual service. If both countries agree to acknowledge co-produced content as each country's contents, both would benefit.

Method for Scale Effect on Front of Flood Wave Occurred by Levee Breach (제방붕괴로 인한 홍수파 선단의 축척효과 보정 방안)

  • Jeong, Seokil;Kim, Sooyoung;Lee, Seung Oh
    • Proceedings of the Korea Water Resources Association Conference
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    • 2016.05a
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    • pp.461-461
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    • 2016
  • 이상기후로 인하여 제방붕괴에 대한 위험성이 높아지고 있고, 이로 인해 발생하는 제내지 내 붕괴 홍수파에 대한 연구가 증가하고 있다. 특히 홍수파 선단의 이동 속도 추정은 제내지의 위험성을 예측하고, EAP 등을 수립하는데 매우 중요한 자료가 될 수 있다. 제내지에서의 선단 홍수파에 대한 예측을 하기 위해서는 해당 지역의 하천특성, 수리특성 및 제방 등 수공구조물 특성뿐만 아니라, 제내지의 지형 및 토지이용 현황 등을 조사하여 수리실험이나 수치모의를 수행해야 하는 것이 일반적이다. 수치해석의 경우 수리실험에 비하여 경제성 및 효율성 측면에서 뛰어날 수 있으나, 제방 붕괴과정 및 메커니즘을 반영하기가 불가능하다. 이에 반해 수리모형실험의 경우 제방붕괴 양상 및 그 과정의 재현이 가능하기 때문에, 제내지에서의 선단홍수파 전파에 관한 보다 정확한 양상을 파악할 수 있을 것이다. 그러나 이러한 실험은 실제 크기의 하천이 아닌 축소모형 또는 개수로에서 수행되었기 때문에, 초기 홍수파의 전파가 축척효과(Scale effect)의 영향을 받을 가능성이 매우 크다. 특히 선단 홍수파의 경우 파가 진행되면서 수심이 낮아지고, 유속이 느려지기 때문에 그 영향은 점차 증대된다고 할 수 있다. 이에 본 연구에서는 이러한 초기 선단 홍수파의 표면장력 영향을 고려한 보정 계수 산정에 대한 연구를 수리실험을 통해 수행하였다. 연구는 크게 4가지 과정으로 구성되었다. 첫째는 농도-표면장력의 관계 규명이며, 둘째는 표면장력-홍수파 전파 속도 관계 규명이다. 셋째는 표면장력과 Weber Number(We)의 관계를 도출하는 것이며, 마지막은 We를 이용하여 한계조건을 제시하는 것이다. 실험은 계면활성제의 농도를 변화시켜가며, 얇은 유리관(D=1.0 mm)에서 물의 상승 높이 및 접촉각을 측정하여 농도와 표면장력의 관계를 측정하였으며, 이러한 결과를 바탕으로 물의 표면장력을 변화시켜 가며 $0.5(B){\times}0.3(L){\times}0.2(H)m$의 Head-tank에 설치된 수문을 빠르게 개방하여, 홍수파가 퍼지는 양상을 관측하였다. 홍수파의 이동 속도는 진행시간에 따라서 퍼짐 넓이를 측정하여 제곱근을 취하는 방식으로 평균속도를 산정하였다. 이러한 관계를 이용하여 표면장력이 없을 경우의 이동속도 및 ??를 도출하였다. 본 연구를 통해 홍수파 전파 특성에 대한 수리실험 자료를 바탕으로 Weber 수를 도출하여 표면장력의 영향을 받는지 여부를 판단할 수 있으며, 표면장력의 영향을 받을 경우, 제시된 결과를 이용하여 홍수파 선단의 속도를 보정할 수 있다. 본 연구 결과는 토대로 축소모형으로 수행되는 홍수파 전파에 대한 수리실험결과의 보정 기초자료로 매우 유용할 것으로 판단된다.

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Pulse Broadening and Intersymbol Interference of the Optical Gaussian Pulse Due to Atmospheric Turbulence in an Optical Wireless Communication System (광 무선통신시스템에서 대기 교란으로 인한 광 가우시안 펄스의 펄스 퍼짐과 부호 간 간섭에 관한 연구)

  • Jung, Jin-Ho
    • Korean Journal of Optics and Photonics
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    • v.16 no.5
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    • pp.417-422
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    • 2005
  • When an optical pulse propagates through the atmospheric channel, it is attenuated and spreaded by the atmospheric turbulence. This pulse broadening produces the intersymbol interference(ISI) between adjacent pulses. Therefore, adjacent pulses are overlapped, and the bit rates and the repeaterless transmission length are limited by the ISI. In this paper, the ISI as a function of the refractive index structure constant that presents the strength of atmospheric turbulence is found using the temporal momentum function, and is numerically analyzed fer the basic SONET transmission rates. The numerical results show that ISI is gradually increasing at the lower transmission rate than the OC-192(9.953 Gb/s) system and is slowly converging after rapid increasing at the higher transmission rate than the OC-768(39.813 Gb/s) system as the turbulence is stronger. Also, we know that accurate information transmission is possible to 10[km] at the OC-48(2.488 Gb/s) system under any atmospheric turbulence, but is impossible under the stronger turbulence than $10^{-14}[m^{-2/3}]$ at the 100 Gb/s system, $10^{-13}[m^{-2/3}]$ at the OC-768 system, and $10^{-12}[m^{-2/3}]$ at the OC-192 system, because the ISI is seriously induced.