• Title/Summary/Keyword: research field

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광산 대규격 갱도에 대한 레디믹스트 숏크리트의 현장 적용성 평가 (A Study on the Field test of the Ready-mixed Shotcrete using in the Large-scale Mine)

  • 김동민;이흥수;신홍준;강동준
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2009년도 세계 도시지반공학 심포지엄
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    • pp.1511-1516
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    • 2009
  • In recent years, the large-scale shaft have been appling in domestic mine for mass production using a large machine, the safety of mine also have been increasing. And the new trial that shotcrete of tunnel field was apply to mine support was progressed. But, the conditions of domestic mine was different from that of tunnel, so, the batch plant of tunnel could not be installed in mine field because of low economical efficiency and difficulty for selection of site. Ready-mixed Shotcrete that mixed with high quality materials and could be controled shotcrete quality is producted in plants and transported to field, so do not need to batch plant. In this study, The Field test of the Ready-mixed Shotcrete was performed in the large-scale mine and was compared with the quality of Field mix shotcrete. As the result of the Field test, compressive strength and rebound of Ready-mixed Shotcrete were superior to these of Field mix shotcrete.

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Active-Matrix Field Emission Display with Amorphous Silicon Thin-Film Transistors and Mo-Tip Field Emitter Arrays

  • Song, Yoon-Ho;Hwang, Chi-Sun;Cho, Young-Rae;Kim, Bong-Chul;Ahn, Seong-Deok;Chung, Choong-Heui;Kim, Do-Hyung;Uhm, Hyun-Seok;Lee, Jin-Ho;Cho, Kyoung-Ik
    • ETRI Journal
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    • 제24권4호
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    • pp.290-298
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    • 2002
  • We present, for the first time, a prototype active-matrix field emission display (AMFED) in which an amorphous silicon thin-film transistor (a-Si TFT) and a molybdenum-tip field emitter array (Mo-tip FEA) were monolithically integrated on a glass substrate for a novel active-matrix cathode (AMC) plate. The fabricated AMFED showed good display images with a low-voltage scan and data signals irrespective of a high voltage for field emissions. We introduced a light shield layer of metal into our AMC to reduce the photo leakage and back channel currents of the a-Si TFT. We designed the light shield to act as a focusing grid to focus emitted electron beams from the AMC onto the corresponding anode pixel. The thin film depositions in the a-Si TFTs were performed at a high temperature of above 360°C to guarantee the vacuum packaging of the AMC and anode plates. We also developed a novel wet etching process for $n^+-doped$ a-Si etching with high etch selectivity to intrinsic a-Si and used it in the fabrication of an inverted stagger TFT with a very thin active layer. The developed a-Si TFTs performed well enough to be used as control devices for AMCs. The gate bias of the a-Si TFTs well controlled the field emission currents of the AMC plates. The AMFED with these AMC plates showed low-voltage matrix addressing, good stability and reliability of field emission, and good light emissions from the anode plate with phosphors.

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Enhancement of Photocurrent Generation by C60-encapsulated Single-walled Carbon Nanotubes in Ru-sensitized Photoelectrochemical Cell

  • Lee, Jung-Woo;Park, Tae-Hee;Lee, Jong-Taek;Jang, Mi-Ra;Lee, Seung-Jin;Kim, Hee-Su;Han, Sung-Hwan;Yi, Whi-Kun
    • Bulletin of the Korean Chemical Society
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    • 제33권8호
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    • pp.2689-2693
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    • 2012
  • Single-walled carbon nanotubes (SWNTs) and $C_{60}$-encapsulated SWNTs ($C_{60}@SWNTs$) are introduced to Ru-sensitized photoelectrochemical cells (PECs), and photocurrents are compared between two cells, i.e., an $RuL_2(NCS)_2$/DAPV/SWNTs/ITO cell and an $RuL_2(NCS)_2$/DAPV/$C_{60}@SWNTs$/ITO cell. [L = 2,2'-bipyridine-4,4'-dicarboxylic acid, DAPV = di-(3-aminopropyl)-viologen, and ITO = indium-tin oxide] The photocurrents are increased by 70.6% in the presence of $C_{60}@SWNTs$. To explain the photocurrent increase, the reverse-field emission method is used, i.e., $RuL_2(NCS)_2$/DAPV/SWNTs/ITO cell (or $RuL_2(NCS)_2$/DAPV/$C_{60}@SWNTs$/ITO cell) as an anode and a counter electrode Pt as a cathode in the external electric field. The improved field emission properties, i.e., ${\beta}$ (field enhancement factor) and emission currents in the reverse-field emission with $C_{60}@SWNTs$ indicate the enhancement of the PEC electric field, which implies the improvement of the electron transfer rate along with the reduced charge recombination in the cell.

On Problematizing IS Research: A Critical Reading of the KMIS SOLOMO Research Agenda

  • 전성현
    • Asia pacific journal of information systems
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    • 제22권4호
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    • pp.31-49
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    • 2012
  • In this essay, we problematize the problematics of the KMIS SOLOMO research agenda. We propose that the SOLOMO agenda is a conditioned product of the various assumptions, biases, premises, and presuppositions that the field of IS collectively succumbs to and shares, and thus needs to be problematized to arrive at a new set of research questions for the field. The problematization begins with the ontology that underlies the agenda. We argue that the agenda is largely drawn from a dichotomic, deep ontology of Human vs. Technology. While such ontology is neither right nor wrong in its own right, we suggest it is what underlies and influences the field's whole mode of inquiry including its research agenda. We propose an alternative ontology, the Actor-Network Theory (ANT), which as a flat ontology provides a radically different set of research questions for the field. Next we take issue with the teleology of the SOLOMO agenda, and suggest that the telos of the agenda, and of the field of IS and the whole of Management discipline together, are anchored upon the capitalist episteme so that it creates a significant hole in its teleological scape. While not in any sense calling for an ideological demagogue, we propose that the field of IS should open itself to an alternative teleology including a leftist perspective. We draw upon the Critical Management Studies (CMS) to explore how further problematization can be made on the SOLOMO agenda, generating questions about its performativity, denaturalization, and reflexivity. As a result of the discussions, a list of new problematized research questions for the SOLOMO agenda is generated. In the end we state the motivation of the essay and call for a critical refurbishing of the field of IS.

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Establishment of the Measurement System of the Magnetic Field for the Study on the Magnetic Field Tolerance of TMP

  • Baik, Kyungmin;Cheung, Wan-Sup;Lim, Jong-Yeon;Choi, Kyoung-Min;Nam, Seung-Hwan
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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    • pp.106.1-106.1
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    • 2013
  • When strong static magnetic field is applied to the TMP, it is expected that the presence of the magnetic field might retard the velocity of the blades which results in the change of the pumping speed of the TMP. However, such effect of the magnetic field on the TMP has not been well characterized. Thus, under the strong magnetic field, monitoring pumping speed as well as generated heat, pressure, and vibration of the TMP may be an important issue to understand the magnetic field tolerance of the TMP and the development of magnetic shielding technique for the key components of the pump. For this purpose, magnetic field generation system to the vertical direction by a circular current source was firstly designed and suggested [K. Baik et al., 44th Annual Conf. KVS, 22(1), 153, (2012)]. In the current study, another magnetic field generation systems are presented to apply the magnetic field to the horizontal and radial directions by the rectangular current sources and the permanent magnets respectively. Such systems were made to generate at least 50 Gauss of magnetic field along the vertical direction and at least 25 Gauss of magnetic field along the horizontal or radial direction. Current study introduces the evaluation system of the magnetic field along the vertical, horizontal, and radial directions and presents the measured experimental results of the magnetic field when such systems are combined with the equipment where TMP will be installed.

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Effective Screening Method for Viviparous Germination of Rice

  • Ju, Young-Cheoul;Han, Sang-Wook;Park, Joong-Soo;Park, Kyeong-Yeol
    • 한국작물학회지
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    • 제45권2호
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    • pp.103-107
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    • 2000
  • The viviparity of 28 rice varieties was tested at 25 days after heading(DAH), 35DAH, and 45DAH in the laboratory and field condition for 12 days. The incubation temperature was 20/l$0^{\circ}C$ (day/night), 25/15$^{\circ}$C$ and 30/20$^{\circ}$C$ in the laboratory test, and under field water conditions in the field test. The biggest varietal difference of viviparity was found in the laboratory test when examined at 45DAH with the 6-day incubation under 25/15$^{\circ}$C$ . At this conditions the mean viviparous ratio was 32.1 % with the range of 53.9 and the variance of 259.5. In the field test, the significant varietal difference in the viviparity was also found in the lodging treatment at 45 DAH for 6 days. Correlation coefficient analysis between the field and laboratory tests was highly significant from 4 days after incubation at 45 DAH and after 6-day incubation at 35 DAH, and correlation coefficient was higher as incubation days in the laboratory and submerged days under field water became longer. Considering the correlation between the field and laboratory tests, varietal difference of viviparity and convenience of testing, the laboratory test at 45 DAH for 6-day incubation under 25/15$^{\circ}$C$ was the most efficient evaluation method for the viviparity of rice cultivar.

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Magnetic Field Standards Using Magnetic Resonance

  • Park, Po Gyu;Kim, Wan-Seop;Joo, Sung Jung;Lee, Hyung Kew
    • 한국자기공명학회논문지
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    • 제21권1호
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    • pp.7-12
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    • 2017
  • The nuclear magnetic resonance (NMR) and atomic magnetic resonance (AMR) plays a fundamental role in achieving a high accuracy of magnetic field measurements. Magnetic field unit (T) was realized based on the shielded proton gyromagnetic ratio (${\gamma}^{\prime}_P$), helium-4 gyromagnetic ratio (${\gamma}_{4He}$) and related techniques. The magnetic field standard system has been disseminated by the NMR magnetometer and electromagnet, a Helmholtz coil system, and AMR magnetometer in the nonmagnetic laboratory. A magnetic field standard below 1 mT has been developed by using Cs and Cs- $^4He$ AMR with automatic compensation of an external magnetic field noise. The standards serve for the calibration of magnetometers and support the test of sensors and materials in the range from $5{\mu}T$ to 2.0 T with (1 to 50) ${\mu}T/T$ uncertainty (k=2).

Three-Dimensional Modeling of the Solar Active Region

  • ;;최광선
    • 천문학회보
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    • 제37권1호
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    • pp.85.2-85.2
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    • 2012
  • In this paper, we introduce the 3D modeling of the coronal magnetic field in the solar active region by extrapolating from the 2D observational data numerically. First, we introduce a nonlinear force-free field (NLFFF) extrapolation code based on the MHD-like relaxation method implementing the cleaning a numerical error for Div B proposed by Dedner et al. 2002 and the multi-grid method. We are able to reconstruct the ideal force-free field, which was introduced by Low & Lou (1990), in high accuracy and achieve the faster speed in the high-resolution calculation (512^3 grids). Next we applied our NLFFF extrapolation to the solar active region NOAA 10930. First of all, we compare the 3D NLFFF with the flare ribbons of Ca II images observed by the Solar Optical Telescope (SOT) aboard on the Hinode. As a result, it was found that the location of the two foot-points of the magnetic field lines well correspond to the flare ribbon. The result indicates that the NLFFF well capture the 3D structure of magnetic field in the flaring region. We further report the stability of the magnetic field by estimating the twist value of the field line and finally suggest the flare onset mechanism.

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Near-field Noise-emission Modeling for Monitoring Multimedia Operations in Mobile Devices

  • Song, Eakhwan;Choi, Jieun;Lee, Young-Jun
    • IEIE Transactions on Smart Processing and Computing
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    • 제5권6호
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    • pp.440-444
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    • 2016
  • In this paper, an equivalent circuit model for near-field noise emission is proposed to implement a multimedia operation-monitoring system for mobile devices. The proposed model includes a magnetic field probe that captures noise emissions from multimedia components, and a transfer function for near-field noise coupling from a transmission line source to a magnetic field probe. The proposed model was empirically verified with transfer function measurements of near-field noise emissions from 10 kHz to 500 MHz. With the proposed model, a magnetic field probe was optimally designed for noise measurement on a camera module and an audio codec in a mobile device. It was demonstrated that the probe successfully captured the near-field noise emissions, depending on the operating conditions of the multimedia components, with enhanced sensitivity from a conventional reference probe.

산업체 현장실습 운영 현황 분석을 통한 개선 방안에 관한 연구 (A Study on the improvement through the present state analysis of the industry field training)

  • 박경우;박익수
    • 공학교육연구
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    • 제19권2호
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    • pp.97-101
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    • 2016
  • This paper examines the industry field training education model, analyze the operational status proposed improvement measures. Data were analyzed using a field training participating students participating industry last three years. On the other hand analysis field training participating students increased, industry participation has decreased. And most of the students took part in the seasonal short-term job training. In addition, it was difficult to analyze the employment status field training operations follow-up member. In this paper, a field training operations support system management models and practical training courses organized field trips how to improve. Field training operations support will be strengthened through the work associated with the company expanding participation model introduced and is expected to increase in the long-term practical training, students participate in field training system improvement. Run the job training Improvement in future research presented in this paper attempts to analyze the students' employment status and results of operations involved.