• Title/Summary/Keyword: engineering characteristics

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A Study on The Engineering Characteristics of Corestone Ground Mass. (핵석지반의 강도 및 변형특성 연구)

  • Lee, Su-Gon;Kim, Dong-Eun;Lee, Chun-Young;Kim, Jae-Heun;Yang, Hong-Suk
    • Proceedings of the Korean Geotechical Society Conference
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    • 2004.03b
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    • pp.327-333
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    • 2004
  • Corestone ground mass has complicated characteristics as it is made up of hard and stiff corestone in a relatively weak and soft matrix. Model corestone ground mass which is physically identical with the stiff corestone in weak matrix were tested in uniaxial compression. The tests show that the increase of the corestone proportion brought the gradual increase of the elastic modulus as well. The ground mass was weaker when the corestone proportion was low while it was stronger in higher corestone proportion. The size of the corestone had no influence on the strength and elastic modulus as long as the proportion of the corestone remains same.

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Piezoelectric Energy Harvesting Characteristics of GaN Nanowires Prepared by a Magnetic Field-Assisted CVD Process

  • Han, Chan Su;Lee, Tae Hyeon;Kim, Gwang Mook;Lee, Da Yun;Cho, Yong Soo
    • Journal of the Korean Ceramic Society
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    • v.53 no.2
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    • pp.167-170
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    • 2016
  • Various piezoelectric nanostructures have been extensively studied for competitive energy harvesting applications. Here, GaN nanowires grown by a nonconventional magnetic field-assisted chemical vapor deposition process were investigated to characterize the piezoelectric energy harvesting characteristics. As a controlling parameter, only the growth time was changed from 15 min to 90 min to obtain different crystallinity and morphology of the nanowires. Energy harvesting characteristics were found to depend largely on the growth time. A longer growth time tended to lead to an increased output current, which is reasonable when considering the enhanced charge potentials and crystallinity. A maximum output current of ~14.1 nA was obtained for the 90 min-processed nanowires.

Investigation of Flying Characteristics of Slider with Micro-actuator (마이크로 액추에이터를 장착한 슬라이더의 부상특성 연구)

  • Moon, Jae-Taek;Chung, Koo-Hyun;Kim, Dae-Eun;Jeon, Jong-Up
    • Journal of the Korean Society for Precision Engineering
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    • v.18 no.9
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    • pp.96-100
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    • 2001
  • As the track density of hard disk drives increases, there is a need for more precise actuation of the head. This can be accomplished by using a high band width micro-actuator. In this work, the flying characteristics of sliders with micro-actuators are investigated with the aim to optimize the head/disk interface performance of such sliders. Contact-start-stop, sweep, and flying height tests are performed and analyzed. The results show that the MEMS based micro-actuator mounted on a slider possess acceptable flying characteristics.

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Carbon nanotube antennas analysis and applications: review

  • El-sherbiny, Sh.G.;Wageh, S.;Elhalafawy, S.M.;Sharshar, A.A.
    • Advances in nano research
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    • v.1 no.1
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    • pp.13-27
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    • 2013
  • Carbon nanotube characterized by additional inductive effect as compared with the traditional conductors like copper wires of the same size. Consequently, carbon nanotubes have high characteristic impedance and slow wave propagation in comparison with traditional conductors. Due to these characteristics, carbon nanotubes can be used as antenna. In view of this, we describe and review the present research progress on carbon nanotube antennas. We present different analysis models and results which are developed to investigate the characteristics of CNT antennas. Then we conclude by summarizing the characteristics of CNT antennas and specifying the operating frequency limit.

Application of Area-Saving RF Test Structure on Mobility Extraction

  • Lee, Jae-Hong;Kim, Jun-Soo;Park, Byung-Gook;Lee, Jong-Duk;Shin, Hyung-Cheol
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.9 no.2
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    • pp.98-103
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    • 2009
  • An RF test structure is proposed and its applicability is confirmed by measuring DC characteristics and high frequency characteristics. Effective mobility extraction is also performed to confirm the validity of proposed test structure. The area of suggested test structure consumed on wafer was decreased by more than 50% and its characteristics do not be degraded compared with conventional structure.

Investigations of Latch-up characteristics of CMOS well structure with STI technology (STI 기술을 채용한 CMOS well 구조에서의 Latch-up 특성 평가)

  • Kim, In-Soo;Kim, Chang-Duk;Kim, Jong-Chul;Kim, Jong-Kwan;Sung, Yung-Kwon
    • Proceedings of the KIEE Conference
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    • 1997.11a
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    • pp.339-341
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    • 1997
  • From this first studies, We have investigated the latch-up characteristics of various CMOS well structures possible with high energy ion implantation processes. In this study, we also investigated those of STI(Shallow Trench Isolation} structures with varing n+/p+ spacing and the depth of trench. STI structure is formed by T-SUPREM4 process simulator, and then latch-up simulations for each case were performed by MEDICI device simulator for latch-up immunity improvement. STI is very effective to preventing the degradation of latch-up characteristics as the n+/p+ spacing is reduced. These studies will allow us to evaluate each technology and suggest guidelines for the optimization of latch-up susceptibility.

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A Study on the Characteristics of DC Flashover with Floating Metallic Objects in Unipolar Ion Field (불평등 전계중에 금속구 및 금속침의 부유 물체가 존재하는 경우의 Flashover특성)

  • Seok, B.Y.;Huh, G.D.;Kim, K.S.;Cho, J.S.;Park, C.H.
    • Proceedings of the KIEE Conference
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    • 1995.11a
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    • pp.469-471
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    • 1995
  • This paper describes the effect of floating metallic object on do flashover characteristics in all gap producing unipolar ion flow field. Needle-to-plane electrodes of 120mm in gap length were used as the main gap electrode and the tested metallic objects were spheres with the radius of 2,10 and 15mm or needles from 5 to 40mm long. The characteristics of flashover voltage vs. location of the floating object are different completely with the shape of the floating metal and polarity of the applied voltage.

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The Effect of Electron Beam Irradiation for Volumn Resistivity in the Molding Compound for Power Semiconductor (전력용 반도체 몰딩재료의 체척고유저항에 미치는 전차선 조사의 영향)

  • Lee, Yong-Woo;Hong, Nung-Pyo;Park, Woo-Hyun;Ga, Chul-Hyun;Lee, Soo-Won;Hong, Jin-Woong
    • Proceedings of the KIEE Conference
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    • 1995.11a
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    • pp.370-372
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    • 1995
  • This paper mainly, describes the electrical characteristics caused by the change of structure in solid state of specimen by electron beam irradiation of high temperature-low expension type molding materials of power semiconductor element. The experiments on physical properties and electrical characteristics for the specimen irradiated electron beam are carried ont. For the investigation on physical properties, XRD analysis is used. And for the experiment of electrical characteristics, measurement of volumn resistivity is used.

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Hysteretic Characteristics of Wells Turbine for Wave Energy Conversion

  • Tae-Hun Kim;Yeon-Won Lee;Yeong-Yeun Hwang
    • Journal of Advanced Marine Engineering and Technology
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    • v.27 no.3
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    • pp.421-428
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    • 2003
  • The aerodynamic characteristics of the Wells turbine for wave energy conversion have been investigated by the numerical simulation to reproduce hysteretic behaviors. The pressure distributions on the suction surface of the blade were investigated to find out the cause of the hysteretic mechanism. The results have shown that the hysteretic behavior is associated with streamwise vertical flow appearing near the suction surface and become more obvious. as the tip clearance and solidity change. Also it has shown that such phenomena occur due to different behaviors of wakes in the accelerating and decelerating flow process. The CFD analysis shows a good agreement with experimental results.

The Outgasing characteristics of MgO film for protecting layer of plasma display panel

  • Song, Byoung-Kwan;Lee, Young-Joon;Lee, Chang-Heon;Hwang, Hyun-Ki;Yeom, Guen-Young
    • 한국정보디스플레이학회:학술대회논문집
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    • 2002.08a
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    • pp.621-624
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    • 2002
  • In this study, outgassing characteristics of MgO films, and the plasma cleaning effects of the deposited MgO films by atmospheric pressure plasma on outgassing rate were compared. The MgO layer was heated up to 350 $^{\circ}C$ and the outgassing characteristics were observed for the heated conditions. As the main impurity species $H_2,\;H_2O,\;N_2,\;CO_2,\;and\;H_2O$ were released from this panel. Impurity species of plasma treatment panel were lower than non-treated panels for the heating temperature

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