• 항공우주산업기술동향
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• 제8권1호
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• pp.118-130
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• 2010

본 논문에서는 헬리콥터 로터 허브 시스템 중 최신의 기술이 적용된 무베어링 허브 시스템에 대하여 적용된 기술에 대한 동향을 기술하였다. 먼저 헬리콥터 로터 허브시스템의 형태별 장단점을 분석하였으며, 무베어링 로터 허브 시스템이 타 허브 시스템에 비하여 갖는 고유의 특징에 대하여 기술하였다. 다음으로 무베어링 로터 허브 시스템의 주요 구성품에 대한 기능 및 역할, 특성에 대하여 기술하였다. 나아가 무베어링 로터 허브를 적용하고 있는 기 개발된 헬리콥터들의 사례에 대하여 기술하였다.

• 한국산학기술학회논문지
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• 제15권5호
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• pp.2769-2777
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• 2014

본 연구는 2008년 중반 이후 중소기업의 수출입 업무에 uTradeHub 시스템이 도입된 이래 해당 시스템의 유용성과 사용자 만족도를 점검한다는 차원에서 i) uTradeHub 수용요인에 따른 시스템의 유용성과 사용자 만족도에 영향을 미치는 요인을 파악하고, ii) 시스템의 유용성이 사용자 만족도에 미치는 영향관계를 분석함으로써 향후 uTradeHub 시스템을 도입하고자 하는 무역업체가 시스템 도입과정에서 간과하기 쉬운 uTradeHub의 수용요인을 효율적으로 관리하여 도입한 시스템의 성과를 최대화할 수 있도록 도움을 주고자 하였다. 설문조사를 통해 수집한 112개의 유효응답 자료를 SPSS 19.0 통계패키지를 이용하여 실증분석 하였으며, 분석결과는 다음과 같다. 첫째, 시스템의 유용성에 유의한 영향을 미치는 uTradeHub 수용요인으로는 상대적 이점, 사용의 편리성, 업무적합성, CEO의 지원, IT인프라 성숙도, 교육/훈련 정도 등이었다. 둘째, 사용자 만족도에 영향을 미치는 uTradeHub 수용요인으로는 상대적 이점, 업무적합성, CEO의 지원, IT인프라 성숙도, 교육/훈련 정도 등이었다. 셋째, 시스템의 유용성은 사용자 만족도에 유의한 영향을 미치는 결과를 보였다.

• 한국문헌정보학회지
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• 제56권4호
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• pp.473-490
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• 2022

본 연구는 저작권을 우회하여 유료로 제공될 학술 논문의 원문을 무료로 제공하고 있는 Sci-Hub에 대해 살펴보고, 2018년 Sci-Hub 측에서 공개한 데이터셋을 바탕으로 국내 Sci-Hub 이용 현황을 분석하여 접근제한에 처한 연구자들의 이용행태를 이해하기 위한 기초적인 바탕을 확립하기 위해 수행되었다. 따라서 Sci-Hub와 관련된 현황을 파악한 후에, 데이터셋을 다운로드된 지역별, 학술 논문의 주제, 출판사, OA 여부, 출간된 연도로 범주를 설정하고 분석하였다. 연구 결과 다운로드가 가장 많이 된 지역은 서울과 수도권이었으며, 자연과학 분야의 논문과 학술지가 가장 많이 다운로드되었고, 대략 20%정도의 논문이 Open Access 상태였다. 2010~2017년에 발간된 논문들이 가장 많이 다운로드 되었으며, IEEE의 논문이 가장 많이 다운로드되어 이를 종합해보면 다운로드된 시점 기준 최근에 발간된 자연과학 계열의 학술논문이 가장 많이 다운로드 되었다는 것을 보여주었다.

• 한국항만경제학회지
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• 제20권2호
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• pp.89-100
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• 2004

Because of a recent trend of the open and globalized world economy, international trade is getting bigger and there is a trade competition among many countries, resulting in competition between harbor industries. Therefore, as hub-port development of China, Japan and Taiwan is more actively progressing than any other times, Korea should prepare a powerful management system to take the initiative over them. Above all, a new recognition of the governmental officers in charge of political management about hub-port industry and early development of the northeast hub-port are needed. To maximize its distinctiveness from competitive ports, port sale should be actively managed. As well, as port functions are diverse, accompanied site development should be prepared. In conclusion, in order to improve functions of a port and develop the port as a general complex of physical distribution, the government should encourage the accompanied site development and support preparation of a customs-free area and a general system of physical distribution.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 춘계학술대회 논문집
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• pp.363-368
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• 2002

An automobile hub is composed of a hollow cylindrical part with inner and outer diameters. These hub diameters must be precise, as any irregularities in them (diameters) can influence/degrade the motion of an automobile with this problem. Highly accurate and reliable hub inner and outer diameters measurement systems are therefore required for inspection of the diameters. In this research, an automobile hub inner and outer diameters measurement system has been developed and tested. The system consists of measuring heads with LVDT sensors, and associated software for automatic measurement and calibration of the diameters and the sensors respectively. The system has been evaluated in comparison with an existing measurement system, and the following outcomes have been achieved; .Improved and guaranteed quality and reliability .Increased productivity and cost reduction. These results prove the system developed in this research to be suitable for automobile hub inspection.

• 무역상무연구
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• 제51권
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• pp.441-464
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• 2011

It is childhood yet in uTradeHub system practical use. According as company's necessity of cost-saving is increased according to trade terms aggravation such as uncertainty of international money market, commodities prices rise, necessity of e-trade practical use in company is increased. Use is inevitable by state that link with e-Nego and e-B/L service with related presentation e-L/C banks is not made. At the present users are doing specification only service this main point, and practical use activation through public information and marketing about service is needed situation because most of, companies which is not using service, do not know about existence availability of uTradeHub system, usage, availability. This study presented five such as early materialization of user center's link and integration, medium and small enterprises e-trade participation extension, utilization ratio raising through government's public information, e-trade cooperation business activation between the country, electronic documents standardization etc. by prompting competition about practical use of uTradeHub system.

• Structural Engineering and Mechanics
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• 제30권4호
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• pp.427-444
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• 2008

A mathematical model for the nonlinear dynamics of a rotating beam with flexible root attached to a rotating hub with elastic foundation is developed. The model is developed based on the large planar and flexural deformation theory and the potential energy method to account for axial shortening due to bending deformation. In addition the exact nonlinear curvature is used in the system potential energy. The Lagrangian dynamics and the assumed mode method is used to derive the nonlinear coupled equations of motion hub rotation, beam tip deflection and hub horizontal and vertical displacements. The derived nonlinear model is simulated numerically and the results are presented and discussed for the effect of root flexibility, hub stiffness, torque type, torque period and excitation frequency and amplitude on the dynamic behavior of the rotating beam-hub and on its stability.

• 한국기계가공학회지
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• 제18권10호
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• pp.104-109
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• 2019

Reverse engineering techniques using 3D scanners and 3D printing technologies are being used in various industries. In this paper, the three-dimensional model is designed for automotive hub parts through 3D scanning and reverse engineering, and the design of hub parts is intended to be printed on FDM-style 3D printers to measure and analyze the dimensions of hub parts designed for reverse design and 3D printed hub parts. Experimental result have shown that the dimensions of 3D printed hub parts are small compared to those of the reverse-engineered dimensions, which are due to the shrinkage of filament materials in 3D printing.

• 한국발생생물학회지:발생과생식
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• 제25권4호
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• pp.313-319
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• 2021

Hub cells comprise a niche for germline stem cells and cyst stem cells in the Drosophila testis. Hub cells arise from common somatic gonadal precursors in embryos, but the mechanism of their specification is still poorly understood. Here we find that RNA binding proteins Lin28 and Imp mediate transcript stability of Bowl, a known hub specification factor; Bowl transcripts were reduced in the testis of Lin28 and Imp mutants, and also when RNA-mediated interference against Lin28 or Imp was expressed in hub cells. In tissue culture Luciferase assays involving the Bowl 3'UTR, stability of Luc reporter transcripts depended on the Bowl 3'UTR and required Lin28 and Imp. Our findings suggest that proper Bowl function during hub cell specification requires Lin28 and Imp in the testis hub cells.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 D
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• pp.2661-2663
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• 2005

To construct the stable back-up system between mini-hubs, we propose the plan of site diversity of asynchronous mini-hub by monitoring outlink carriers and error data. In this paper, we made hardware and software to control mini-hub system for site diversity back-up by switching SDBS equipment through communication between master mini-hub and slave mini-hub.