• Title/Summary/Keyword: Ahn Jae-Hong

검색결과 618건 처리시간 0.03초

Current progress in bolometric performance measurement of breadboard AMON-RA energy channel instrument for deep space albedo measurement

  • Kim, Yun-Jong;Yi, Hyun-Su;Ryu, Dong-Ok;Jung, Kil-Jae;Ahn, Ki-Beom;Oh, Eun-Song;Lee, Jae-Min;Ham, Sun-Jung;Yoon, Ji-Yeon;Yoon, Ho-Seop;Hong, Jin-Seok;Yang, Ho-Soon;Lee, Han-Shin;Kim, Sug-Whan;Lockwood, Mike
    • 한국우주과학회:학술대회논문집(한국우주과학회보)
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    • 한국우주과학회 2008년도 한국우주과학회보 제17권1호
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    • pp.26.1-26.1
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    • 2008
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스크롤 압축기 상부 캡의 방사 소음 해석을 위한 유한 요소/경계 요소 모델링 (FEM/BEM Modeling of the Top Cap of Scroll Compressors for Analysis of Noise Radiation)

  • 안재홍;송재수;김성원
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2000년도 춘계학술대회논문집
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    • pp.346-350
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    • 2000
  • In scroll compressors, there are two major noise sources. Sturctural path: excitation of the compressor housing by unbalance forces and forces generated by compression cycle. Gas cavity path: excitation of top cap by discharge gas pulsation. In this study, in order to analyze the radiated noise generated by the discharge gas pulsation, FEM/BEM model of the top cap is established. Measured pressure of discharge pulsation is introduced in the FEM model as the excitation and vibration response is calculated. Radiated sound pressure is then obtained by BEM method based on this vibration response. Results are compared with the measured data. It is shown that the trend of the noise radiation can be predicted in this approadch.

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Electrical Characterization of Electronic Materials Using FIB-assisted Nanomanipulators

  • Roh, Jae-Hong;You, Yil-Hwan;Ahn, Jae-Pyeong;Hwang, Jinha
    • Applied Microscopy
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    • 제42권4호
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    • pp.223-227
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    • 2012
  • Focused Ion Beam (FIB) systems have incorporated versatile nanomanipulators with inherent sophisticated machining capability to characterize the electrical properties of highly miniature components of electronic devices. Carbon fibers were chosen as a model system to test the applicability of nanomanipulators to microscale electronic materials, with special emphasis on the direct current current-voltage characterizations in terms of electrode configuration. The presence of contact resistance affects the electrical characterization. This resistance originates from either i) the so-called "spreading resistance" due to the geometrical constriction near the electrode - material interface or ii) resistive surface layers. An appropriate electrode strategy is proposed herein for the use of FIB-based manipulators.

다중이용 시설물 내부 위상학적 분석과 통행량 측정 결과의 비교 연구 (A Comparative Study of Multi-use Facilitues inner Topological Analysis and Traffic Measurements)

  • 황재홍;안병주;김회율;김재준
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2009년도 추계 학술논문 발표대회
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    • pp.273-276
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    • 2009
  • Interior space of large scale composition facilities influences in walk population of distance according to trade and space rescue and walk population of distance is armed business activity. First, chose representative COEX mall of domestic representative multiplex utilization facilities on greate upper limbs for progress of research. Because executing space analysis of COEX mall interior, can analyzed the walk amount and location and also confirm result that floating population according to accessibility increases. Produced time, day of the week, the passageway passing amount through CCTV on actuality COEX mol interior to compare this. Was proved that it is quantity in the passageway passing amount and analysis incidental of the passing amount that get executing space difference.

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Visible-photoresponsive Nitrogen-Doped Mesoporous TiO2 Films for Photoelectrochemical Cells

  • Bae, Jae-Young;Yun, Tae-Kwan;Ahn, Kwang-Soon;Kim, Jae-Hong
    • Bulletin of the Korean Chemical Society
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    • 제31권4호
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    • pp.925-928
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    • 2010
  • Nitrogen-doped $TiO_2$ ($TiO_2$:N) nano-particles with a pure anatase crystalline structure were successfully synthesized through the hydrolysis of $TiCl_4$ in an ammonia aqueous solution. The samples were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), $N_2$-sorption, and UV-vis diffuse reflectance spectra (UV-vis DRS) techniques. The absorption edge of nitrogen-doped $TiO_2$ shifted into the visible wavelength region. The photoelectrochemical (PEC) performances were investigated for the $TiO_2$ mesoporous electrodes doped with different nitrogen concentrations. The $TiO_2$:N electrodes exhibited much higher PEC responses compared to the pure $TiO_2$ electrode because of the significantly enhanced visible-photoresponsibility of the $TiO_2$:N electrodes.

Hey Host, Do Communicate with Guests: Empirical Evidence from Airbnb

  • Ju, Jae-Hyeon;Kim, Dong-Yeon;Ryu, Il-Han;Ahn, Jae-Hyeon;Bang, Young-Sok
    • 아태비즈니스연구
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    • 제9권3호
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    • pp.1-9
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    • 2018
  • Despite a wide practice of e-market sellers communicating with their consumers, little attention is given to how the practice affects consumers' purchase decision process. Based on the text analysis of 10,479 accommodation cases obtained from Airbnb, we empirically examine the relationship between the sellers' communication efforts and the wish-listing behaviors of guests. We find that the wish-listing is positively associated with the communication efforts of a host, such as (1) the feedback volume, (2) tailored messages and personalized contents, and (3) contingent responses to guest reviews. We discuss the theoretical and practical implications of the study.

태양광 직렬 아크 검출기의 검출 성능 및 DWT 알고리즘 연산 속도 개선 (Arc Detection Performance and Processing Speed Improvement of Discrete Wavelet Transform Algorithm for Photovoltaic Series Arc Fault Detector)

  • 조찬기;안재범;이진한;이기덕;이진;류홍제
    • 전력전자학회논문지
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    • 제26권1호
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    • pp.32-37
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    • 2021
  • This study proposes a DC series arc fault detector using a frequency analysis method called the discrete wavelet transform (DWT), in which the processing speed of the DWT algorithm is improved effectively. The processing time can be shortened because of the time characteristic of the DWT result. The performance of the developed DC series arc fault detector for a large photovoltaic system is verified with various DC series arc generation conditions. Successful DC series arc detection and improved calculation time were both demonstrated through the measured actual arc experimental result.

한약재 포제 가공의 현대적 연구 현황 (A Literature Survey of the Modern Techniques Used for the Processing of Herbal Medicines)

  • 오주희;신재석;안은석;이성준;이종철;임준홍;홍시갑;홍준기;이영주
    • Journal of Pharmaceutical Investigation
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    • 제39권4호
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    • pp.275-297
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    • 2009
  • Herbal medicines have been used worldwide, particularly in the Far East countries, for thousands of years. Herbal medicines comprise complex mixtures of different phytochemical substances, and their nature may vary substantially depending on many factors related to the cultivation condition, area and harvest time. The processing of the herbal medicines significantly affects their pharmacological and toxicological properties. In this paper, we discuss current research that deals with the techniques for processing Chinese herbal medicines. These results will provide a scientific basis for developing new techniques for the processing of herbal medicines.

Long-term Environmental Changes: Interpretations from a Marine Benthic Ecologist's Perspective (II) -Eutrophication and Substratum Properties

  • Yoo Jae-Won;Hong Jae-Sang;Lee Jae June
    • Fisheries and Aquatic Sciences
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    • 제2권2호
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    • pp.210-217
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    • 1999
  • Chemical oxygen demand (COD), phytoplankton cell number and chlorophyll-a concentration (Chl-a), sediment mean grain size and ignition loss were studied to determine their temporal trends in the study area. Historical data of COD, cell number and Chl-a were gathered from the late 1960s or early 1980s to 1997, and trends in temporal domain were obtained from a simple regression. Sediments for grain size and ignition loss (as organic contents in sediments) were sampled from the Chokchon macrotidal flat bimonthly from September 1990 to November 1996, and were analyzed using the decomposition method of time series analysis. In general, the first three data showed increasing trends based on regression analysis. The trends of sediment grain size fluctuated in a neutral pathway while those of ignition loss yielded no increasing pattern. In contrast with the suggestions from Ahn and Choi (1998) who reported a coarsening variation in sediment grain size to be a cause of the directional and remarkable changes of macrofaunal communities in this area, we could not find such a corresponding variation pattern from our samples. In diagnosing eutrophication, a paradoxical phenomenon was encountered between the trends in water column (COD, cell number and Chl-a) and sediment (ignition loss) data. In this paper, we inferred the possible processes that produce the discrepancy. Some explanations and biological responses to eutrophication were predicted and discussed.

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One-Stop Web Services 개발 (Development of One-Stop Web Services)

  • 조희형;안성수;안부영;박재홍;박형선
    • 한국정보과학회:학술대회논문집
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    • 한국정보과학회 2005년도 가을 학술발표논문집 Vol.32 No.2 (2)
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    • pp.223-225
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    • 2005
  • 근래 들어 생명과학 및 생명정보에 대한 관심이 높아지면서 활발한 연구 활동의 결과물로 많은 정보를 얻을 수 있게 되었다. 또한 방대한 생명정보를 분석할 수 있는 많은 알고리즘이 개발되었으며 웹 기술이 발달함에 따라 생명정보의 활용도가 높아져서 다양한 방법으로 정보서비스가 가능하게 되었다. 특히 XML, SOAP, WSDL, UDDI를 사용하는 Web Services는 분산 컴포넌트 기반의 컴퓨팅 기술로 최신의 기술이다. 이에, 바이오인포매틱스센터에서는 CCBB, NCBI, EBI, DDBJ 등의 사이트에서 배포한 Web Services에 접근하여 입력 값과 출력된 결과를 확인 및 유지하고, 객체들의 흐름을 볼 수 있는 프로그램으로 One-Stop Web Services를 개발하였다. One-Stop Web Services는 GUI 환경의 인터페이스로 사용자에게는 용이한 실행 환경을 제공하므로, Web Services 개발자에게 사용자 인터페이스 개발 부담을 줄일 수 있다.

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