• Title/Summary/Keyword: over current characteristics

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Designs for Development of Bra Tops for the New Senior Generation

  • Lim, Hosun;Cho, Hakyung
    • Fashion & Textile Research Journal
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    • v.15 no.3
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    • pp.358-363
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    • 2013
  • Due to recent changes in increased life expectancy, economic power and social development, the new senior generation (focusing on people in their fifties) represents a new market power with strong competitiveness. The new senior generation is the generation after the baby boomers, with characteristics that include a high-level of education, increased income, a high-level of consumption, increased assets, self-fulfillment desires and individuality. Demands in the senior fashion industry are expected to gradually increase and the underwear industry that targets the new senior generation is expected to grow rapidly. These demands will require product development for the new senior generation based on emotional and socio-cultural characteristics. The current new senior underwear market is under the process of R&D with a focus on body shape changes; however, there are limited studies on emotional and socio-cultural approaches. This study formulates a basic design plan for different age groups based on an analysis of the situation of bra wear (current inconveniences, demand and needs) by women in their fifties and over. Subsequently, a functional active bra top that considers activity and comfort was proposed for women in their fifties, an all-in-one foundation bra top that shapes the body was proposed for women in their sixties, and comfort bra tops that are comfortable and easy to put on and take off were proposed for women in their seventies and over.

Electrical Properties of 18[kV] ZnO Surge Arrester Stressed by the Mixed DC and 60[Hz] AC Voltages (직류+60[Hz]교류 중첩전압에 대한 18[kV] ZnO 피뢰기의 전기적 특성)

  • Lee, Su-Bong;Lee, Seung-Ju;Lee, Bok-Hee
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.21 no.10
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    • pp.66-72
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    • 2007
  • This paper describes the characteristics of power loss and leakage currents flowing through new and used 18[kV] zinc oxide(ZnO) surge arrester under the mixed DC and AC voltages. The mixed DC and AC voltage generator of 50[kV] peak was designed and fabricated. The I-V curves of ZnO surge arrester were measured as a function of the voltage ratio K. The I-V curves under the mixed DC and AC voltages lay between the pure DC and AC characteristics, and the cross-over phenomenon in both I-V curves and R-V curves was observed at the low current region. As a result, the increase of DC component in the mixed voltages causes the increase of resistive component of total leakage current of ZnO surge arrester. Also, in the case of same applied voltage, the leakage current flowing through the used ZnO surge arrester was higher than that of the new ZnO surge arrester.

Tidal and Sub-tidal Current Characteristics in the Kangjin Bay, South Sea, Korea

  • Ro, Young-Jae
    • Ocean Science Journal
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    • v.42 no.1
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    • pp.19-30
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    • 2007
  • This study analyzed the current meter records along with wind records for over 500 days obtained in the Kangjin Bay, South Sea, Korea spanning from March, 2003 to Nov. 2005. Various analyses include descriptive statistics, harmonic analysis of tidal constituents, spectra and coherence, the principal axis, progressive vector diagrams. These analyses can illustrate the response of residual current to the local wind resulting in the net drift with rotational motion. Current speed ranges from -28 to 33 (cm/sec), with standard deviations from 6.5 to 12.9 (cm/sec). The harmonic analyses of the tidal current show the average form number, 0.12 with semi-diurnal type and the rectilinear orientation of the major axis toward northeast. The magnitudes of the semi-major range from 12.7 to 17.7 (cm/sec) for M2 harmonics, while for S2 harmonics, they range from 6.3 to 10.4 (cm/sec), respectively. In the spectral and coherency analysis of residual current and wind, a periodicity of 13.6 (day) is found to be most important in both records and plays an important role in the net drift of residual current. The progressive vector diagrams of residual current and wind show two types of behaviors such as unidirectional drift and rotational motion. It was also found that 3 % rule holds approximately to drive 1 (cm/sec) drift current by 30 (cm/sec) wind speed based on the correlation of the semi-major axis of wind and residual current.

Fabrication of Thin Film Transistor Using Ferroelectrics

  • Hur, Chang-Wu;Kim, Jung-Tae
    • Journal of information and communication convergence engineering
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    • v.2 no.2
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    • pp.93-96
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    • 2004
  • The a-Si:H TFT using ferroelectric of $SrTiO_3$ as a gate insulator is fabricated on glass. Dielectric characteristics of ferroelectric are superior to $SiO_2$ and $Si_{3}N_{4}$. Ferroelectric increases on-current, decreases threshold voltage of TFT and also improves breakdown characteristics. The a-SiN:H has optical band gap of 2.61 eV, retractive index of 1.8∼2.0 and resistivity of $10^{13}$~$10^{15}$ $\Omega$cm, respectively. Insulating characteristics of ferroelectrics are excellent because dielectric constant of ferroelectric is about 60∼100 and breakdown strength is over 1MV/cm. TFT using ferroelectric has channel length of 8∼20 $\mu\textrm{m}$ and channel width of 80∼200 $\mu\textrm{m}$. And it shows that drain current is 3.4$\mu\textrm{A}$ at 20 gate voltage, $I_{on}$/$I_{off}$ is a ratio of $10^5$~$10^8$ and $V_{th}$ is 4∼5 volts, respectively. In the case of TFT without ferroelectric, it indicates that the drain current is 1.5 $\mu\textrm{A}$ at 20 gate voltage and $V_{th}$ is 5∼6 volts. With the improvement of the ferroelectric thin film properties, the performance of TFT using this ferroelectric has advanced as a gate insulator fabrication technology is realized.

Effects of Chloride Concentration and Applied Current Density on Stray Current Corrosion Characteristics of 6061-T6 Al Alloy for Electric Vehicle Battery Housing (전기자동차 배터리 하우징용 6061-T6 알루미늄합금의 전식 특성에 미치는 염화물농도 및 인가전류밀도의 영향)

  • Shin, Dong-Ho;Kim, Seong-Jong
    • Corrosion Science and Technology
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    • v.21 no.5
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    • pp.348-359
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    • 2022
  • Interest in electric vehicle is on the rise due to global eco-friendly policies. To improve the efficiency of electric vehicles, it is essential to reduce weights of components. Since electric vehicles have various electronic equipment, the research on stray current corrosion is required. In this research, a galvanostatic corrosion experiment was performed on 6061-T6 Al alloy for electric vehicle battery housing using chloride concentration and applied current density as variables in a solution simulating an acid rain environment. As a result of the experiment, when chloride concentration and applied current density were increased, corrosion damage became larger. In particular, pitting damage was dominant at an applied current density of 0.1 mA/cm2. Pitting damage over the entire surface was found at a current density of 1.0 mA/cm2. In conclusion, chloride concentration had a relatively large effect on localized corrosion. The applied current density had a great effect on uniform corrosion. However, in the case of applied current density, localized corrosion was also greatly affected by interaction with chloride.

Analysis of the Melting Characteristics of a Blade Type Fuse Used for Vehicles Due to Overload (과부하에 따른 차량용 블레이드형 퓨즈의 용단특성 해석)

  • Choi, Chung-Seog
    • Fire Science and Engineering
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    • v.24 no.2
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    • pp.38-43
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    • 2010
  • The purpose of this study is to secure the basis for judgment on the cause of an accident by analyzing the melting characteristics of a blade type fuse used for vehicles due to overload. In order to increase the reliability of the test, it was conducted by connecting the electrical system with conditions similar to those of an actual vehicle to apply the load. Carbonization pattern experiment of fuse by outside flame applied Korean Standard (KS). The fuse melted by the overcurrent showed a smooth cross-section while the test terminals, clear plastic body, etc., burnt out by the external flame was badly deformed. When 185% of the rated current (27.8A) was applied to a cable of 15A rated current onto which an over-capacity fuse (20A) was installed, the fuse melting time was 217 seconds. In addition, when a load current of 28.8[A] (139%) was applied, the fuse's test terminal and terminal blade were not burnt out although foam was observed on some parts of the plastic body. When a load capacity of 28.2[A] (141%) was applied to a cable of 15A rated current onto which an over-capacity fuse (30A) was installed, the fuse melting time was approximately 10 seconds. When a load current of 35.8[A] (119%) was applied, the fuse's test terminal and terminal blade were not burnt out, although some parts of the plastic body was swelled. However, it was observed that the switch terminal melted if approximately six minutes lapsed under such conditions. When a load capacity of 39.4[A] (131%) was applied to a cable of 15A rated current onto which an over-capacity fuse (30A) was installed, the fuse melted in approximately 69 seconds, and the test terminal and terminal blade were not burnt.

A Design of 40V Power MOSFET for Low Power Electronic Appliances (저용량 가전용 40V급 Power MOSFET 소자의 설계 및 제작에 관한 연구)

  • Kang, Ey-Goo;Ann, Byoung-Sup;Nam, Tae-Jin;Kim, Bum-June;Lee, Young-Hon;Chung, Hun-Suk
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.06a
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    • pp.115-115
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    • 2009
  • Current sensing in power semiconductors involves sensing of over-current in order to protect the device from harsh conditions. This technique is one of the most important functions in stabilizing power semiconductor device modules. The Power MOSFET is very efficient method with low power consumption, fast sensing speed and accuracy. In this paper, we have analyzed the characteristics of proposed sense FET and optimized its electrical characteristics to apply conventional 40 V power MOSFET by numerical and simulation analysis. The proposed sense FET has the n-drift doping concentration $1.5\times10^{14}\;cm^{-3}$, size of $600\;{\mu}m^2$ with $4.5\;{\Omega}$, and off-state leakage current below $50\;{\mu}A$. We offer the layout of the proposed Power MOSFET to process actually. The offerd design and optimization methods are meaningful, which the methods can be applied to the power devices having various breakdown voltages for protection.

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A Design Method on Power Sense FET to Protect High Voltage Power Device (고전압 전력소자를 보호하기 위한 Sense FET 설계방법)

  • Kyoung, Sin-Su;Seo, Jun-Ho;Kim, Yo-Han;Lee, Jong-Seok;Kang, Ey-Goo;Sung, Man-Young
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.22 no.1
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    • pp.12-16
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    • 2009
  • Current sensing in power semiconductors involves sensing of over-current in order to protect the device from harsh conditions. This technique is one of the most important functions in stabilizing power semiconductor device modules. The sense FET is very efficient method with low power consumption, fast sensing speed and accuracy. In this paper, we have analyzed the characteristics of proposed sense FET and optimized its electrical characteristics to apply conventional 450 V power MOSFET by numerical and simulation analysis. The proposed sense FET has the n-drift doping concentration $1.5{\times}10^{14}cm^{-3}$, size of $600{\um}m^2$ with $4.5\;{\Omega}$, and off-state leakage current below $50{\mu}A$. We offer the layout of the proposed sense FET to process actually. The offerd design and optimization methods are meaningful, which the methods can be applied to the power devices having various breakdown voltages for protection.

A Study on the electrical characteristics of high voltage MOSFET with the various structure under the high temperature condition (Asymmetric 고 내압 MOSFET의 구조적 변화에 따른 고온 영역에서의 전기적 특성 분석)

  • Choi, In-Chul;Lee, Jo-Woon;Park, Tae-Su;Koo, Yong-Seo
    • Proceedings of the IEEK Conference
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    • 2005.11a
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    • pp.579-582
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    • 2005
  • In this study, the electrical characteristic of asymmetric high voltage MOSFET (AHVMOSFET) for display IC was investigated. Measurement data are taken over range of temperature (300K-400K) and various extended drain length, and gate oxide thickness ($175{\AA}$, $350{\AA}$). In high temperature condition, drain current decreased over 30% and max transconductance deceased over 40%, and specific on-resistance increased over 30% in comparison with room temperature.

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Stability evaluation and microseismic monitoring around Large Underground Oil Storage Cavern in Over-stressed Rock Mass (과지압 암반 내 대규모 지하 유류비축기지 안정성 평가 및 Microseismic 계측)

  • Lee Hee-Suk;Lee Dae-Hyuck;Kim Ho-Yeong;Hong Jee-Soo;Choi Young-Tae;Kim Seok-Jin;Park Yeon-Jun
    • 한국터널공학회:학술대회논문집
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    • 2005.04a
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    • pp.189-201
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    • 2005
  • Brittle failure has been detected in over-stressed rock mass during the construction of oil storage cavern. The main characteristics of stress induced brittle failure of the site are introduced. Various evaluation and measures are sought to stabilize the over-stressed rock mass. The major results from numerical analysis of the cavern are presented, and from current microseismic monitoring to detect hazard from brittle failure are presented.

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