• 제목/요약/키워드: Research field

검색결과 24,715건 처리시간 0.048초

Electron Holography of Advanced Nanomaterials

  • Shindo, D.;Park, H.S.;Kim, J.J.;Oikawa, T.;Tomita, T.
    • Applied Microscopy
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    • 제36권spc1호
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    • pp.63-69
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    • 2006
  • By utilizing a field emission gun and a biprism installed on a transmission electron microscope (TEM), electron holography is extensively carried out to visualize the electric and magnetic fields of nanomaterials. In the electric field analysis, the distribution of electric potential in a sharp tip made of W coated with $ZrO_2$ is visualized by applying the voltage to the tip. Denser contour lines due to the electric potential are observed with an increase in the bias voltage. In the magnetic field analysis by producing the strong magnetic field with a sharp magnetic needle made of a permanent magnet, the in situ experiment is carried out to investigate the magnetization of hard magnetic materials. The results of these experiments clearly demonstrate that electron holography is a promising advanced transmission electron microscopy technique to characterize the electric and magnetic properties of nanomaterials.

Field Emission Current Enhancement in CNTs by Laser Irradiation

  • Jeong, Tae-Won;Yu, Se-Gi;Yi, Whi-Kun;Lee, Chang-Soo;Lee, Jeong-Hee;Heo, Jung-Na;Yoo, Ji-Beom;Kim, Won-Seok;Lee, Y.H.;Kim, J.M.
    • Journal of Information Display
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    • 제2권4호
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    • pp.23-28
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    • 2001
  • Field emission characteristics of carbon nanotubes(CNTs) on four kinds of metallic substrates have been investigated under the irradiation of a laser. The field emission measurement reveals that after laser irradiation the current was increased and new humps at the field emission current was found. The current enhancement was thought to have occurred due to the fact that the electrical contact between CNTs and metals was improved due to the irradiation of the laser.

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고온초전도 동기모터의 계자코일 제작과 특성 (Fabrication and Characteristics of Field Coils for HTS Motor)

  • 손명환;이언용;백승규;조영식;권운식;권영길
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2003년도 하계학술대회 논문집 B
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    • pp.735-737
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    • 2003
  • A superconducting motor consisting of high temperature superconducting (HTS) rotor and air-core stator is under development in Korea Electrotechnology Research Institute. HTS motor was designed for having the rated power of 100hp at 1800 rpm. HTS field winding is composed of sixteen HTS race track shaped coils wound with stainless steel-reinforced Bi-2223 tape conductor by react and wind fabrication method. Nomex Paper was used for electrical insulation. Each of four magnet pole assemblies was constructed with four double pancake sub-coils, mechanically stacked and electrically in series. Four magnet assemblies were fixed on an aluminum support structure to make effective heat transfer. Critical current (Ic) of HTS field winding was 41A but minimum Ic of sub-coils was 35A at 77K and self field. Joule heat generated in HTS field winding was 2.11W at 77K and 35A.

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Gain characteristics of SQUID-based RF amplifiers depending on device parameters

  • Lee, Y.H.;Yu, K.K.;Kim, J.M.;Lee, S.K.;Chong, Y.;Oh, S.J.;Semertzidis, Y.K.
    • 한국초전도ㆍ저온공학회논문지
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    • 제21권1호
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    • pp.10-14
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    • 2019
  • Radio-frequency (RF) amplifiers based on direct current (DC) superconducting quantum interference device (SQUID) have low-noise performance for precision physics experiments. Gain curves of SQUID RF amplifiers depend on several parameters of the SQUID and operation conditions. We are developing SQUID RF amplifiers for application to measure very weak RF signals from ultra-low-temperature high-magnetic-field microwave cavity in axion search experiments. In this study, we designed, fabricated and characterized SQUID RF amplifiers with different SQUID parameters, such as number of input coil turn, shunt resistance value of the junction and coupling capacitance in the input coil, and compared the results.

국제경영 분야에 관한 연구동향 분석 (Review on Literatures of International Management)

  • 권기환;권재현
    • 무역학회지
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    • 제45권6호
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    • pp.227-258
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    • 2020
  • The field of international management has consistently been recognized as one of the key research pillars in the grand scope of trade studies. In this paper, we conducted critical review on literatures of international management, which were published in Korea Trade Review from 1975 to 2019. Especially, this paper analyzed 'when did research results in the field of international management appear in Korea Trade Review for the first time?', 'how many papers in the field of international management have been published in Korea Trade Review so far?', 'what topics have the papers in the field of international management published in Korea Trade Review mainly described?', and 'what research methods have the papers in the field of international management published in Korea Trade Review adopted?' In particular, this paper compared the similarities and differences between the research issues in leading global journals and those of international management research papers published in Korea Trade Review. In addition, some implications for future research would be suggested regarding what characteristics of international management studies will be meaningful to be published in the Korea Trade Review.

국가 기상기술력 수준 평가 - 한국, 미국, 일본을 대상으로 한 비교 연구 - (Capability Assessment on Meteorological Technology - Comparative Study of Technological Prowess on Korea, U.S., and Japan -)

  • 김세원;박길운;조창범;이영곤;임덕빈
    • 대기
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    • 제21권3호
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    • pp.319-336
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    • 2011
  • The objective of this study was to assess the meteorological capability of Korea by comparing with that of the U.S. and Japan as of 2010. The research was conducted based on various indices and surveys, and quantified the results using the Gordon's scoring model. The index assessment used 11 items derived from 9 segments - surface observation, advanced observation and observations quality in the observation field; data assimilation, numerical model and infrastructure in the data processing field; forecast accuracy in the forecast field; climate prediction and climate change in the climate field - in this research, we classified the meteorological technology into four fields. In the survey assessment, another 10 items in addition to the above 11 ones (total 21 items) were used. In the field of climate, Korea was found to lag far behind the U.S. (96.5p) and Japan (90.5p) with 77.6 points out of 100, which is 18.9 and 12.9 points lower than them respectively. On the other hand, Korea showed the narrowest gap with Japan (95.3p) and the U.S. (94.2) in the forecasting field, recording 90.3 points. Particularly, in surface observation, infrastructure and forecast accuracy segment, Korea was on a par with the U.S. and Japan, boasting 100.5 percent compared to their counterparts. However, in advanced observation, data quality and climate change segment, Korea was only at the level of 81.5 percent compared to that of the U.S. and Japan. All in all, the technological prowess of Korea, scoring 84.6 points, stood at 89.7 percent of that of the U.S. (94.3p) and 91.9 percent of Japan (92.1p).

최근 유·아동복 관련 연구 동향에 관한 연구 (A study on recent research trends related to infant & children's clothes)

  • 김윤희;이진희
    • 한국의상디자인학회지
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    • 제20권4호
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    • pp.175-186
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    • 2018
  • These days, due to increased income levels, lower birthrate, and increased marriage age, interest and investment in children has increased, and infant & children's clothes has become more upgraded, differentiated, and diversified. In accordance with the change of the infant & children's clothes market, Examine the research trends of the papers in the journals. Used 'KISS', 'DBpia', 'Korea Institute of Science and Technology Information', in the search system, and 137 papers were searched for by using key word, 'infant's clothes' and 'children's clothes'. The year of publication is limited to 2001 to 2017, and they are classified into 5-year units and again the papers were classified by year, by journal, by field of clothing research (Technical Design & Production, Fashion Marketing, Textile System, Fashion Design), and frequency and percentage were used as data analysis. The number of articles related to infant & children's clothes increased such as 39 in 2001~2005, 43 in 2006~2010, and 55 in 2011~2017. The distribution of articles by journals has been published mainly in the journal of the Korean Society of Clothing and Textiles, but as the journals were diversified, they were distributed evenly in other journals related to the apparel. In the presentations according to the research field by year, from 2001 to 2005, the ratio of apparel design and production was high, but since 2006, many papers related to fashion marketing and fashion design have been published. The research contents of the field of clothing research are as follows: 41 articles in design production field, focusing on dimensional system and pattern design, 40 articles in fashion design field, focusing on design development and design preferences, 46 articles in fashion marketing field, focusing on consumer behavior and marketing management. And 10 articles in apparel material system field, focusing on research on cloth science materials, but they are less well studied than others, but these studies should be actively pursued in the future.

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Far-field Transport of Effluent Plumes Discharged from Masan Sea Outfalls

  • Kim, Young-Do;Kang, See-Whan;Seo, Il-Won;Oh, Byung-Cheol
    • Ocean and Polar Research
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    • 제22권2호
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    • pp.69-80
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    • 2000
  • A 3-D particle tracking model with normalized characteristic equations has been developed to predict the variation of near-field mixing characteristics and the far-field transport of the effluent plumes discharged from sea outfalls. The model was applied to the case study on the Masan sea outfall plumes discharged through a submerged multiport-diffuser. Numerical simulations of the effluent transport for 15 days which cover neap and spring tidal cycles in Masan Bay were conducted using fall velocities of the solid wastes and the initial plume characteristics obtained from normalized near-field characteristic equations. The results showed that time variations in near-field minimum dilutions with tidal ambient flow conditions are about $45{\sim}49$. Most of the heavy particles in the effluent plumes were settled and deposited in the vicinity of the outfalls immediately, and the finer particles were transported eastwards 3 km away from the outfalls for 15 days. A similar depositional trend of contaminated sediment was also found during a recent field survey.

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한국 패션디자인·미학 분야의 연구동향 - 「복식」(2001~2010)을 중심으로 - (A Survey on the Research Trends of Fashion Design·Aesthetic Field in Korea - Focused on the Journal of the Korean Society of Costume (2001~2010) -)

  • 최해주
    • 복식
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    • 제62권3호
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    • pp.152-162
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    • 2012
  • The Purpose of this study was to investigate research trends of subject matter in fashion design aesthetic field in clothing and textiles and to suggest the information for the future directions for fashion business and research. 1089 articles with clothing and textiles subject matter, 523 articles with fashion design aesthetic field in the Journal of Korean Society of Costume from 2001 through 2010 were analyzed. The major conclusions of the study are as the following: 1. Fashion design aesthetic field took absolute majority in the researches of the clothing and textiles in the Journal of Korean Society of Costume, in the 2000s. 2. Fashion design aesthetic field showed more proportions in the latter half of the decade. 3. History of costume, fashion marketing field were followed. Textiles science field took extremely little proportion. 4. In fashion design aesthetic field, topic of fashion design elements and types took absolute majority. 5. Fashion aesthetics, fashion design development, makeup hair style topics were followed.

Numerical investigation of glass windows under near-field blast

  • Chiara Bedon;Damijan Markovic;Vasilis Karlos;Martin Larcher
    • Coupled systems mechanics
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    • 제12권2호
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    • pp.167-181
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    • 2023
  • The determination of the blast protection level and the corresponding minimum load-bearing capacity for a laminated glass (LG) window is of crucial importance for safety and security design purposes. In this paper, the focus is given to the window response under near-field blast loading, i.e., where relatively small explosives would be activated close to the target, representative of attack scenarios using small commercial drones. In general, the assessment of the load-bearing capacity of a window is based on complex and expensive experiments, which can be conducted for a small number of configurations. On the other hand, nowadays, validated numerical simulations tools based on the Finite Element Method (FEM) are available to partially substitute the physical tests for the assessment of the performance of various LG systems, especially for the far-field blast loading. However, very little literature is available on the LG window performance under near-field blast loads, which differs from far-field situations in two points: i) the duration of the load is very short, since the blast wavelength tends to increase with the distance and ii) the load distribution is not uniform over the window surface, as opposed to the almost plane wave configuration for far-field configurations. Therefore, the current study focuses on the performance assessment and structural behaviour of LG windows under near-field blasts. Typical behavioural trends are investigated, by taking into account possible relevant damage mechanisms in the LG window components, while size effects for target LG windows are also addressed under a multitude of blast loading configurations.