• Title/Summary/Keyword: U-turn

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Emission Behavior of Screen Printed CNT Field Emitters for Advanced Lamp Application

  • Leer, Myoung-Bok;Kim, Dae-Jun;Song, Yoon-Ho
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.691-692
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    • 2009
  • Screen printable CNT pastes were formulated including conductive nano particles (CNPs) and their properties were investigated with an expectation of stable cold cathodes for advanced lamp application. CNT cathodes showed a turn-on field of 1~1.5V/um, a life time of ~100 hours at an emission current density of 10uA/$cm^2$ for DC-bias. Detailed analysis of measured I-V was carried out by applying Fowler-Nordheim model to trace down the origin of emission property degradation.

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Trends in Information Services: Implications to Korean Libraries (정보써어비스의 새로운 추세와 적용문제에 관한 고찰)

  • Noh Ock-Soon
    • Journal of the Korean Society for Library and Information Science
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    • v.13
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    • pp.73-94
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    • 1986
  • The purpose of this article is to take a look into the past twenty years and to evaluate the changes in the organization of the library and the information function during this time period. Academic and special libraries are the ones that have made an impressive progress and innovations to keep pace with a changing environment. New technologies and ideas have brought strong supporters of offering various specialized information services to the library users. The different approaches and experiments to better perform this professional role in the library and in turn, the efforts in the educational institutions to meet the challenges were reviewed through the literature. Much of the literature available regarding the reference and information function deals mainly with the trends in the u. s. libraries. The implications of these trends to Korean libraries and library education are sought in view of our social, economic, and educational circumstances as well as our user behavior.

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Toward Developing a Mobile Channel Extension Model: Roles of Compatibility, Subjective Norm, and Media Influences

  • Lee, Hyun-Hwa;Kim, Ji-Hyun
    • Journal of the Korean Society of Clothing and Textiles
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    • v.35 no.12
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    • pp.1425-1439
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    • 2011
  • The present research developed and empirically examined a theoretical model called a Mobile Channel Extension Model for consumer behavior toward mobile commerce. We proposed three antecedents: compatibility of, subjective norm regarding, and media influence regarding mobile use for communication purposes that influence the attitude toward the subjective norm and media influences of mobile use for shopping. These in turn positively influenced the consume's intention to use mobile devices for shopping. A Structural equation modeling analysis, using the data collected from a national online survey of 524 U. S. multichannel shoppers, confirmed the proposed model. The theoretical implications of these effects were discussed and managerial suggestions were made for both academicians and practitioners.

복소 라플라스변환에 의한 동적 페이저변환

  • Park, Chang-Byeong;Lee, Seong-U;Im, Chun-Taek
    • Proceedings of the KIPE Conference
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    • 2010.11a
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    • pp.46-47
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    • 2010
  • 일반적인 스위칭 콘버터의 교류 시변 특성을 시불변 회로로 변환시키는 페이저변환 기법이 차츰 널리 쓰이고 있으나 정적 응답특성을 구하는 데에 주로 국한되고 있다. 본 논문에서는 페이저변환 이론을 확장하여 단상, 다상의 모든 AC콘버터(DC-AC, AC-DC, AC-AC)와 모든 직병렬 공진형 콘버터(DC-DC)의 동적 응답특성을 일반적으로 구할 수 있는 새로운 이론을 제안한다. 본 논문에서는 복소 턴 비율(complex turn-ratio)을 갖는 전자변압기와 허수의 저항을 갖는 회로에 페이저변환을 적용하기 위해, 복소 라플라스변환을 도입하였다. 이를 통해 교류 콘버터 회로를 해석하고, 시뮬레이션을 통해 타당성을 검증하였다.

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Methods of Separating Used Plastics for Recycling (폐플라스틱의 선별기술)

  • 윤여환
    • Resources Recycling
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    • v.6 no.2
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    • pp.12-21
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    • 1997
  • Plastics waste constitutes approximately 23% by volume of the municipal solid waste(MSW) generated in the U.S. each year, and have slow rate of degradation in the environment. Therefore, there is a great deal of public pressure to recycle plastics, and more than 100 million people participate in the curbside recycling programs. Despite the high level of public interest, only 3.5% of the plastic are recycled, which is substantially lower than the recycle rates of other materials such as paper fibers, glass, and iron. Although a large part of the reason is due to the low price of virgin polymers, which in turn is due to the low price of oil, it is possible to make the plastics recycling as a profitable business by developing advanced technologies. In this communication, various methods of separating pplastics from metals and from each other are discussed.

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The MOSFET Hump Characteristics Occurring at STI Channel Edge (STI 채널 모서리에서 발생하는 MOSFET의 험프 특성)

  • 김현호;이천희
    • Journal of the Korea Society for Simulation
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    • v.11 no.1
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    • pp.23-30
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    • 2002
  • An STI(Shallow Trench Isolation) by using a CMP(Chemical Mechanical Polishing) process has been one of the key issues in the device isolation[1] In this paper we fabricated N, P-MOSFEET tall analyse hump characteristics in various rounding oxdation thickness(ex : Skip, 500, 800, 1000$\AA$). As a result we found that hump occurred at STI channel edge region by field oxide recess. and boron segregation(early turn on due to boron segregatiorn at channel edge). Therefore we improved that hump occurrence by increased oxidation thickness, and control field oxide recess( 20nm), wet oxidation etch time(19HF,30sec), STI nitride wet cleaning time(99HF, 60sec+P 90min) and fate pre-oxidation cleaning time (U10min+19HF, 60sec) to prevent hump occurring at STI channel edge.

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Comparison of the Practical Use Condition of e-finance Portal Site between Korea and U.S.A. (한.미간 e-finance 금융포털사이트의 활용실태 비교)

  • Kim Dong-Gyoon;Cha Soon-Kwean
    • Management & Information Systems Review
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    • v.7
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    • pp.21-51
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    • 2001
  • For increasing the competitiveness and efficiency of Korea's finance industry under the new e-finance paradigm, this paper compared the practical use of finance portal site' on service parts and stage between Korea and U.S.A.. The services which can be served from site are banking, mortgage and credit loan, stock, card, retirement tax, PFM(Personal Finance Management), EBPP(Electronic Bill Presentment and Payment) and Account Aggregation and so on. The stage of site can be divided as the information provide stage which only gives information about service parts, on-line transaction stage which real-time transaction is possibile and PFM services provide stage according to development process. As a result, the beginning of finance portal service in Korea was lated about 10years and more than it of U.S.A. So the development stage of domestic portal site is still staying in the first step and the providing services and contents or business model development parts are also in the same stage than U.S.A. Resides, Korea's sites mainly focus on their first service parts even though they recently aim internet finance portal, and provide not real time transaction but finance information. On the other hand, the U.S.A. site support substantially not only various on-line transactions but also distinctive personal services like PFM(Personal Finance Management), EBPP(Electronic Bill Presentment and Payment), Account Aggregation and Trans-account, brokerage, education center, mortgage loan, mutual fund, option, pension fund and IPOs and so on. Thus, the site of Korea need to establish real type of internet finance portal which provides one-stop services on every type of finance to customers in the real time and also require the strategic integration among finance institutions. The next turn, they need to build information system and education center to give best satisfaction to customers and acquire customer information and marker environment changes and need to provide distinctive services to quality customers throughout database from this. Also the site should provide various type of banking services which refereed above like PEM, EBPP and education center etc, and the government of Korea should support the building of IT infrastructure to Physical, legal, systematic, sociocultural, technical and human resource sections. This paper provided the future movement direction of the domestic finance portal through comparison and analysis on the practical use of it between Korea and U.S.A. and also wanted to contribute for developing and reading of Korea finance portal in the new era of the finance paradigm.

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A Study on Roundabout Modeling and Saturation for Level Of Service (회전교차로 서비스수준 분석을 위한 모형개발 및 포화도 산정 연구)

  • Chang, Hyunho;Yoon, Byoungjo;Lee, Jinsoo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.39 no.6
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    • pp.869-875
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    • 2019
  • The service level of the roundabout is estimated through an analytic model using the geometrical characteristics and parameter values obtained from the observations. Although a lot of researches have been conducted on the rotational intersection through an analytical model, the case of variable combinations is enormous, suggesting the range and service level of appropriate traffic volume according to the case study or limited characteristics through simulation. Therefore, in this study, the roundabout analysis model was constructed by using Visual Basic Application to make variable adjustment more easily. The constructed model analyzes traffic conditions according to various situations and analyzes the characteristics of roundabouts. As the result of analysis, the more the ratio of left turn and U-turn, the more the traffic distribution of each approached road was biased to one side, the limit traffic volume of the roundabout decreased and congestion appeared quickly. In particular, the more uneven the distribution of traffic was, the less the Saturation traffic volume was affected by the turnover rate.

Logistic Regression Accident Models by Location in the Case of Cheong-ju 4-Legged Signalized Intersections (사고위치별 로지스틱 회귀 교통사고 모형 - 청주시 4지 신호교차로를 중심으로 -)

  • Park, Byung-Ho;Yang, Jeong-Mo;Kim, Jun-Young
    • International Journal of Highway Engineering
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    • v.11 no.2
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    • pp.17-25
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    • 2009
  • The goal of this study is to develop Logistic regression model by accident location(entry section, exit section, inside intersection and pedestrian crossing section). Based on the accident data of Chungbuk Provincial Police Agency(2004$\sim$2005) and the field survey data, the geometric elements, environmental factor and others related to traffic accidents were analyzed. Developed models are all analyzed to be statistically significant(chi-square p=0.000, Nagelkerke $R^2$=0.363$\sim$0.819). The models show that the common factors of accidents are the traffic volume(ADT), distant of crossing and exclusive left turn lane, and the specific factors are the minor traffic volume(inside intersection model) and U-turn of main road(pedestrian crossing model). Hosmer & Loineshow tests are evaluated to be statistically significant(p$\geqq$0.05) except the entry section model. The correct classification rates are also analyzed to be very predictable(more than 73.9% to all models).

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Thermal Performance Evaluation of Junction Thermal Bridge according to Installation Position of Window

  • Lee, Soo-Man;Kim, Dong-Yun;Ahn, Jung-Hyuk;Eom, Jae-Yong;Shin, U-Cheul
    • KIEAE Journal
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    • v.17 no.3
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    • pp.15-21
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    • 2017
  • Purpose: "Building energy design standard" is used to limit the thermal transmittance of building in Korea. However, it only covers the insulation standard for each appropriate elements of a building, not the thermal performance of Junction thermal bridge of windows and doors installed in wall. Therefore in this study, we have evaluated the thermal performance of Junction thermal bridge depending on installation method and position of windows and provide it as design data. Method: We analyzed heat transfer of 4-Track sliding window and tilt & turn triple glazed window that are placed in the first class category on window energy efficiency rating using Window 7.4 and Therm 7.4. Result : First, linear thermal transmittance of 4-Track sliding window differs by 2.2 times or more depending of installation method and location. It is higher than the linear thermal transmittance, 0.01W/mK, proposed by Passivhaus. Second, linear thermal transmittance of Tilt & turn triple glazed window differs by 7.7 times or more depending of installation method and location. The average linear thermal transmittance was less than 0.01W /mK when windows were installed on the internal wall insulation by the fixed hardware attachment method. Third, the thermal losses of a window caused by a junction thermal bridge are inversely proportional to the window area and converge gradually as the area increased.