• Title/Summary/Keyword: research field

검색결과 24,816건 처리시간 0.05초

Carbon nanotube / silane hybride film for highly efficient field emitter

  • ;;;;이건웅
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 2010년도 하계학술대회 논문집
    • /
    • pp.181-181
    • /
    • 2010
  • Few-walled carbon nanotubes (FWNTs)-based field emitters with long term stability are fabricated by using a spray method. Tetraethylorthosilicate (TEOS) sol as a binder was mixed with dispersed solution of FWNTs to enhance the adhesion of FWNTs on the cathode substrate. Due to the strong intermolecular interaction of TEOS to the functional groups attached on CNTs and substrate, CNTs are tightly adhered to the cathode electrode when heat treatment is performed at $150^{\circ}C$ for 1 hour, resulting in a stable electron emission of CNT emitters for long time. Excellent field emission characteristics were exhibited, with a large field enhancement factor and low turn-on voltage, comparable to those of CNT emitters fabricated by a screen printing of CNT paste. Therefore, FWNTs / TEOS hybrid films could be utilized as an alternative for the efficient and reliable field emitters.

  • PDF

A Critical Review of the Research on Learning during Field-trips

  • Choi, Mee-Young
    • 한국과학교육학회지
    • /
    • 제25권1호
    • /
    • pp.57-77
    • /
    • 2005
  • This review is aimed at the understanding of learning in field-trips relating to education in outdoor activities. The review specifically concerns what studies have been undertaken by seeking evidence from research published between 1950 and 2004. The review indicates three common arguments on learning during field-trips. First, the learning in an informal learning environment based on first-hand experiences is most significant when it has meaning for the learner from field-trips. Second, learning aims and strategies in field-trips have evolved along with world-wide concerns towards the environment. Third, the experiences from field-trips can impact significantly on students' cognitive and affective learning. However, the research of field-trip experiences from outdoor activities has focused on learning outcomes far more than on the learning characteristics which facilitate students' learning. Therefore, further study is required, which can provide clear evidence on how such learning characteristics through field-trips can help studentsto successfully attain educational goals.

국제연구협력정보 DB 구축을 위한 메타데이터 개발에 관한 연구 (A Study on Metadata Development for Establishing International Research Cooperation Information Database)

  • 노영희
    • 한국비블리아학회지
    • /
    • 제29권2호
    • /
    • pp.5-34
    • /
    • 2018
  • 본 연구에서는 국제연구협력관련 모든 정보유형을 발굴하고 각 유형별로 정보를 수집하여 데이터베이스로 구축하고자 하였다. 이를 위해 연구진이 메타데이터를 일차적으로 개발하고 메타데이터 전문가들과의 논의과정을 거쳐 1차적으로 메타데이터를 개발하였으며, 이에 대해 국제연구협력 관련 전문가들을 대상으로 설문조사를 수행하였다. 뿐만 아니라 각 정보원 유형별 메타필드에 데이터를 수집하여 입력하였으며, 메타필드별로 실제 데이터가 존재하는지 등의 과정을 거쳐 메타필드를 검증하였다. 본 연구에서 설계한 DB 유형은 국제연구협력정보원 DB, 국제연구협력 사업 DB, 국제연구협력 전문가 DB, 국제연구협력 기관 DB, 국제기구 DB, 기타 DB 등이며, 이에 대해 설문조사를 수행하고 실제 데이터를 입력하여 필드를 검증한 결과, 설문조사 결과와 필드별 데이터 입력률은 상당히 높은 일치율을 보였다. 다만 국제기구 데이터 필드만은 이용자의 높은 중요도 평가에도 불구하고 10%이하의 데이터 입력률을 보이는 필드가 25% 정도 있는 것으로 확인되었다.

수도 포장진입로의 설계기준에 관한 연구 (A Study on Design Standard for Paddy Field Ramp)

  • 김병갑;이중용;신승엽;김학주;이용복
    • Journal of Biosystems Engineering
    • /
    • 제26권6호
    • /
    • pp.517-524
    • /
    • 2001
  • Steep and narrow ramp installed in the paddy field makes it difficult and sometimes dangerous to drive agricultural machines on it. Because agricultural machinery become larger and heavier, it is necessary to revise design standard for ramp to provide safe travel. This study was conducted to revise the design standard fur paddy field ramp, especially for its width and slope. A mathematical model predicting travelling path of a tractor on paddy field ramp and farm road was developed and simulated. To verify this model, field tests were carried out. The model could predict trvelling path with RMS Error of 12.5cm and 8.2cm, which were judged to be adoptable fur determining the width of paddy field ramp. By applying this model to 110ps tractor, which was assumed to be the largest tractor in Korea, width of paddy field ramp was determined as over 3.6m. The slope of paddy field ramp, which provided tractor with 10% of the total weight of the tractor and the mounted implement as reaction force at front wheel against ground was analyzed by considering weight transfer effect on a ramp. The result showed that adequate slope of paddy field ramp was 14°.

  • PDF

건물용 고분자 전해질 연료전지 금속분리판 유동장 형상 변화에 따른 산소 확산 특성에 대한 연구 (A Study on Oxygen Diffusion Characteristics According to Changes in Flow Field Shape of Polymer Electrolyte Membrane Fuel Cell Metallic Bipolar Plate for Building)

  • 박동환;손영준;최윤영;김민진;홍종섭
    • 한국수소및신에너지학회논문집
    • /
    • 제32권4호
    • /
    • pp.245-255
    • /
    • 2021
  • Various studies about metallic bipolar plates have been conducted to improve fuel cell performance through flow field design optimization. These research works have been mainly focused on fuel cells for vehicle, but not fuel cells for building. In order to reduce the price and volume of fuel cell stacks for building, it is necessary to apply a metallic flow field, In this study, for a metallic flow field applied to a fuel cell for building, the effect of a change in the flow field shape on the performance of a polymer electrolyte membrane fuel cell was confirmed using a model and experiments with a down-sizing single cell. As a result, the flow field using a metal foam outperforms the channel type flow field because it has higher internal differential pressure and higher reactants velocity in gas diffusion layer, resulting in higher water removal and higher oxygen concentration in the catalyst layer than the channel type flow field. This study is expected to contribute to providing basic data for selecting the optimal flow field for the full stack of polymer electrolyte membrane fuel cells for buildings.

Research Ethics in the Aviation Service Industry

  • Soyeon PARK
    • 연구윤리
    • /
    • 제5권1호
    • /
    • pp.7-11
    • /
    • 2024
  • Purpose: This study seeks to discuss research ethics, not only the academic honesty and sincerity that researchers who study aviation services academically should have, but also the direction of the moral aspects that are fundamentally required as researchers. Additionally, this study seeks to examine the realistic problems of research related to the aviation service industry, a field of social science. Lastly, focusing on research ethics in the aviation service field, we will look at the theoretical background and the problems in the actual research field, and draw implications based on this. Research design, data and methodology: This study conducted an exploratory study through a selection process based on research ethics topics and research ethics related to the aviation service industry. Results: Efforts to systematize research ethics in research areas related to the aviation service industry, which is a field of social science, require efforts to expand the scope of systematization of research ethics related to the aviation service industry by referring to systemization efforts in other academic fields. In addition, specific systemization efforts will be needed through cooperation between universities, research institutes, and academic organizations. Also, concrete systematization efforts will be needed through cooperation between universities and academic organizations.

인문학 분야 연구데이터를 위한 연구논문의 의미구조 기반 메타데이터 연구 (A Study on the Metadata based on the Semantic Structure of the Humanities Research Articles for Research Data)

  • 안병군;고영만
    • 한국비블리아학회지
    • /
    • 제33권1호
    • /
    • pp.345-369
    • /
    • 2022
  • 본 연구의 목적은 인문학 분야 연구데이터와 연구논문을 연계할 수 있는 '인문학 분야 연구데이터를 위한 연구논문 의미구조 기반 메타데이터'를 개발하는 것이다. 인문학 분야 연구자의 관심 정보를 파악하기 위해 키워드 유형화를 진행하고 이를 일반적인 연구논문의 의미구조를 기준으로 분석함으로써 인문학 분야의 특성을 반영하기 위해 추가될 요소를 확인하였다. 이를 기반으로 인문학 분야 연구논문의 의미구조 기반 메타데이터를 구성하였으며 해당 메타데이터가 인문학 분야 연구데이터의 메타데이터로서 적합한지를 평가하기 위하여 인문학 분야 연구자를 대상으로 설문을 진행하였다. 인문학 분야 연구논문의 의미구조를 기반으로 도출된 17개의 메타데이터 요소 중 인문학 분야 연구데이터 메타데이터로 활용하기에 적합하다고 판단된 요소는 7개이며, 그 외 10개 요소는 사용 가능한 요소로 확인되었다. 평가 결과를 바탕으로 인문학 분야 연구데이터를 위한 연구논문 의미구조기반 메타데이터를 구성하였다.

2종의 엽록소 측정기를 이용한 포장내 벼의 엽록소 함량 분포 측정 (Measurement of Variability of Chlorophyll Contents in Paddy Fields Using Two Kinds of Chlorophyll Meter)

  • 성제훈;서상룡;박우풍;정인규;김상철;이충근
    • Journal of Biosystems Engineering
    • /
    • 제28권3호
    • /
    • pp.245-252
    • /
    • 2003
  • This study was investigated the possibility of measuring chlorophyll in paddy crops using two kinds of chlorophyll meters(SPAD-502, Field Scout). The results of correlation analysis showed the 0.7758(r$^2$) relationship between the chlorophyll contents of paddy leaves measured by SPAD and spectrophotometer. It indicates that chlorophyll content in paddy crops could be measured using the SPAD. Considering the data of the SPAD and Field Scout there was significant difference between their chlorophyll contents measured by the SPAD and Field Scout. Likewise, such results were consistent with the corrected data using light intensity. According to the results, it can be concluded that it is difficult to describe the rice chlorophyll measured by the Field Scout more accurately than the SPAD when using one standard spectrum and another spectrum for reflectance measuring. The chlorophyll variance measured at a research institute and a farmer's field revealed that the output of SPAD was more reliable than that of the Field Scout.

System Requirement Review of Lunar Surface magnetometer on the CLPS program

  • Jin, Ho;Kim, Khan-Hyuk;Lee, Seongwhan;Lee, Hyojeong;Seon, Daerac;Jung, Byungwook;Jang, Yunho;Park, Hyeonhu
    • 천문학회보
    • /
    • 제45권1호
    • /
    • pp.40.1-40.1
    • /
    • 2020
  • The Korea Astronomy and Space Science Institute is participating as a South Korean partner in the Commercial Lunar Payload Services (CLPS)of NASA. In response, the Korea Astronomy and Space Science Institute is currently conducting basic research for the development of four candidate instrument payloads. The magnetic field instrument is one of them and it's scientific mission objective is the moon's surface magnetic field investigation. Therefore, the development requirement of the lunar surface magnetic field instrument were derived and the initial conceptual design was started. The magnetic field instrument has a 1.2 meter boom which has two three-axis fluxgate magnetometer sensors and one gyro sensor to get a attitude information of the boom. The concept of measuring the lunar surface magnetic field will carry out using multiple sensors by placing semiconductor type magnetic field sensors inside the electric box including boom mounted fluxgate sensors. In order to overcome the very short development period, we will use the KPLO (Korean Lunar Pathfinder Orbiter) magnetometer design and parts to improve reliabilities for this instrument. In this presentation, we introduce the instrument requirements and conceptual design for the Lunar surface magnetic field instruments.

  • PDF

Antenna Measurement on Cylindrical Surface in Fresnel Region Using Direct Far-Field Measurement System

  • Oh, Soon-Soo;Kim, Joung-Myoun;Yun, Jae-Hoon
    • ETRI Journal
    • /
    • 제29권2호
    • /
    • pp.135-142
    • /
    • 2007
  • The small anechoic chambers built by many small-/medium-sized companies and universities present difficulties in testing electrically large antennas because the chamber size cannot satisfy the far-field criterion of large antennas. In this paper, a method for Fresnel-region measurement on a cylindrical surface with variation of the measurement height is proposed and verified by both calculations and experiments. We implement the proposed method using a direct far-field measurement system by adding a few supporting structures. The results show good accuracy.

  • PDF