• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.6
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• pp.807-814
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• 1999

In this paper, it is shown that high frequency current can be controlled to concentrate near the desired path in a conducting plate. A conducting plate is modelled to examine current distribution. And current distribution is analyzed in view of the frequency and geometric characteristics of current path. The high frequency current behavior from the analysis is compared with the experiments. The results, obtained by the experiments of test specimens, are in good agreement with the analytical results.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.312-313
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• 2015

For the traceability of high current measuring sensors of high power testing department II(HPTD II) in Korea Electrotechnology Research Institute(KERI), additional comparison tests with reference test object were performed repeatedly. The first intercomparison has been carried out between the reference shunt for Asia and high current shunt of HPTD II in 2013. This paper compares the test results of the calibration in 2014 with them in 2015. The assigned new scale factor of high current sensors will be applied to high power tests in HPTD II until the next high current intercomparison.

• Progress in Superconductivity and Cryogenics
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• v.24 no.1
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• pp.1-7
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• 2022

So far, large-scale scientific devices such as nuclear fusion tokamaks and high energy circular accelerators were constructed using high-current conductors made of metallic superconducting wires. Recently, as REBCO superconducting wires usable in high magnetic fields have been developed by several companies, researchesto apply high current cable type REBCO conductors to next-generation large superconducting magnets were also started. High critical currents of several kA or more in high magnetic fields have been successfully demonstrated on test samples of REBCO cable conductors by several research groups. In this review article, the main features and properties of the representative high current REBCO conductors such as CORC(Conductor On Round Core), TSTC(Twisted Stacked-Tape Cable) and RACC(Roebel-Assembled Coated Conductor), which are currently being developed at abroad are briefly introduced. Research activities of high-current density REBCO MHOS(Multi HTS layers on One Substrate) conductor at KERI, whose structure is different from other cable type REBCO conductors are also shortly introduced.

• Proceedings of the KIPE Conference
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• 2013.07a
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• pp.36-37
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• 2013

This paper presents high voltage operation sensing boost converter with high side current. Proposed topology has three functions which are high voltage driving, high side current sensing and low voltage boost controller. High voltage gate driving block provides LED dimming function and switch function such as a load switch of LED driver. To protect abnormal fault and burn out of LED bar, it is applied high side current sensing method with high voltage driver. This proposed configuration of boost converter shows the effectiveness capability to LED driver through measurement results.

• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.700-702
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• 2005

The most electrical apparatus should be able to withstand short-time current and peak current during a specified short time until circuit breakers have interrupted fault current. It defines the short-time withstand ability of electric a apparatus to be remain for a time interval under high fault current conditions. It is specified by both dynamic ability and thermal capability. KERI(Korea Electrotechlology Research Institute) recently constructed the new short-time current and low voltage short circuit testing facilities. This paper shows short- circuit calculation of transformer and describes high current measuring system, and evaluate the result of short-time withstand test used in $3{\phi}$ 90MVA short-time current testing facilities.

• Korean Journal of Materials Research
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• v.33 no.4
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• pp.159-163
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• 2023

Zinc-ion Batteries (ZIBs) are currently considered to be effective energy storage devices for wearable electronics because of their low cost and high safety. Indeed, ZIBs show high power density and safety compared with conventional lithium ion batteries (LIBs) and exhibit high energy density in comparison with supercapacitors (SCs). However, in spite of their advantages, further current collector development is needed to enhance the electrochemical performance of ZIBs. To design the optimized current collector for high performance ZIBs, a high quality graphene film is suggested here, with improved electrical conductivity by controlling the defects in the graphene film. The graphene film showed improved electrical conductivity and good electron transfer between the current collector and active material, which led to a high specific capacity of 346.3 mAh g^-1 at a current density of 100 mA g^-1, a high-rate performance with 116.3 mAh g^-1 at a current density of 2,000 mA g^-1, and good cycling stability (68.0 % after 100 cycles at a current density of 1,000 mA g^-1). The improved electrochemical performance is firmly because of the defects-controlled graphene film, leading to improved electrical conductivity and thus more efficient electron transfer between the current collector and active material.

• Journal of the Korean Society of School Health
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• v.32 no.2
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• pp.77-87
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• 2019

Purpose: This study was conducted to examine the prevalence of current smoking and the factors that influence current smoking among male high school students in Korea according to school type. Methods: Data were extracted from the Korea Youth Risk Behavior Web-Based Survey (2017) and multiple logistic regression was used based on complex sample analysis. The study sample comprised of 15,777 male high school students: 12,583 from general high schools (GHS) and 3,194 from specialized vocational high schools (SVHS). Results: The prevalence of current smoking was significantly higher in SVHS students (19.6%) compared to GHS students (12.6%). Low academic achievement, depressive symptoms, current drinking, and high household economic status were commonly associated with current smoking in male students from both school types. However, exposure to secondhand smoking at home, non-exposure to anti-smoking advertisement, exposure to tobacco advertisement, participation in smoking prevention or cessation education were related to current smoking in GHS students, while living in rural area was associated with current smoking in SVHS students. Conclusion: To reduce current smoking among male high school students, it is necessary to develop smoking prevention policies reflecting the factors associated with current smoking that are different by school type.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.318-318
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• 2000

Current signal square based on switch current is presented in this article. This is the new technique that can design current signal square circuit by using switch-current memory cell, current square and sample and hold technique, which have been presented by the general switch-current. This principle which is present have the good electrical characteristics such as the low input impedance, high output impedance and high frequency response. The system can also operate in the audio frequency range to the high frequency current signal. The system application of this technique can be apply to the current signal multiplier by quarter square technique. The experimental results agree well with the theory as high accuracy and linearity.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.1390-1395
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• 2004

Recently, the load increasement and new regenerative systems of electrified railway system make it a difficult to distinguish between the load current and fault current. The failure of traction system perhaps causes over-current to flow. The high current can collapse other railway systems. If failures of the traction system takes place, the failures are detected and protected lest it should provoke high current flow. The over current from such a traction system failure permit to charge high tension voltage and produces high temperature arc, voltage instability, current cutting, and break down railway systems. The traction system failures detect and the system has to immediately cut off from over-current flow. To isolate the failure, the system can distinguish failure current from current flows. It forces us to adapt such as a new intelligent protection system. The protective system in traction system play a role of detecting and isolating failure points. In this paper, we proposed intelligent algorithm for discriminating normal and abnormal situation instead of the system being operated abnormally.

• Journal of the Microelectronics and Packaging Society
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• v.12 no.1 s.34
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• pp.9-16
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• 2005

This paper presents the development of new anisotropic conductive adhesives with enhanced thermal conductivity for the wide use of adhesive flip chip technology with improved reliability under high current density condition. The continuing downscaling of structural profiles and increase in inter-connection density in flip chip packaging using ACAs has given rise to reliability problem under high current density. In detail, as the bump size is reduced, the current density through bump is also increased. This increased current density also causes new failure mechanism such as interface degradation due to inter-metallic compound formation and adhesive swelling due to high current stressing, especially in high current density interconnection, in which high junction temperature enhances such failure mechanism. Therefore, it is necessary for the ACA to become thermal transfer medium to improve the lifetime of ACA flip chip joint under high current stressing condition. We developed thermally conductive ACA of 0.63 W/m$\cdot$K thermal conductivity using the formulation incorporating $5 {\mu}m$ Ni and $0.2{\mu}m$ SiC-filled epoxy-bated binder system to achieve acceptable viscosity, curing property, and other thermo-mechanical properties such as low CTE and high modulus. The current carrying capability of ACA flip chip joints was improved up to 6.7 A by use of thermally conductive ACA compared to conventional ACA. Electrical reliability of thermally conductive ACA flip chip joint under current stressing condition was also improved showing stable electrical conductivity of flip chip joints. The high current carrying capability and improved electrical reliability of thermally conductive ACA flip chip joint under current stressing test is mainly due to the effective heat dissipation by thermally conductive adhesive around Au stud bumps/ACA/PCB pads structure.