• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.1
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• pp.47-51
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• 2000

To make a practical application of a micro-strain sensors with ultrahigh sensitivity, a strain on electrical properties of micro-patterned amorphous (Fe\ulcornerco\ulcorner)\ulcornerSi\ulcornerB\ulcorner films had influenced on the impedance over frequency range from 1 MHz to 1 GHz. Reflecting excellent magnetomachanical couping properties of films, high frequency impedance was subject to change sensitively by a strain : a change in impe-dance of 39% was observed at 200 MHz applied a strain of 224$\times$10\ulcorner. To determine a optimum shape of micro-patterned films, film impedance was analyzed by virtue of its constitutive components of resis-tance and reactance. Result was shown that reduction of the resistance term(hence increase of resultant reactance term) of impedance is more effective for enhancing the strain sensitivity of films at relatively low frequency range.

• Proceedings of the KIEE Conference
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• 1999.07d
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• pp.1581-1583
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• 1999

Epoxy Compound has been used as insulation material in cable accessories. During the applying voltage to cable, heat shock is induced to accessory by the temperature difference between atmosphere and conductor. In this study, crack resistance, thermal and mechanical properties were evaluated about conventional epoxy compound and rubber toughened epoxy compound. Because rubber absorbs the stress caused by heat shock, crack resistance of rubber toughened epoxy compound is high. In the case of low thermal expansion coefficient, the compound shows high crack resistance because of low volumetric change.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.210-213
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• 1999

A battery is the device that transforms the chemical energy into the direct-current electrical energy directly without a mechanical process. Unit cells are connected in series to obtain the necessary voltage, while being connected in parallel to organize capacity for load current and to decrease the internal resistance for corresponding the sudden shift of the load current. The circular-current, however, could be occurred when the system is driven in parallel. As a result, the new batteries are heated by over-change and discharge, and the over charge current makes to increase the rust of the positive grid and consequently the shortened life of the new batteris would be shown. In this paper, the internal resistance of charge and discharge will be balanced, through inserting the resistance into the system by way of calculation of the changed amount of internal resistance.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1331-1332
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• 2007

In the present works, we investigate the thermal characteristics on Ag/$As_{2}S_{3}$ and Ag/$As_{40}Ge_{10}Se_{15}S_{35}$ amorphous chalcogenide thin film structure for PMC (Programmable Metallization Cell).As the results of resistance change with the temperature on Ag/$As_{40}Ge_{10}Se_{15}S_{35}$ amorphous chalcogenide thin film, the resistance was abruptly dropped from the initial resistance of 1.32 M ${\Omega}$ to the saturated value of 800 ${\Omega}$ at $203^{\circ}C$. On the other hand, the resistance increased to 1.3 $M{\Omega}$ at $219^{\circ}C$.

• Journal of Sensor Science and Technology
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• v.30 no.3
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• pp.181-184
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• 2021

Interest in healthcare and wearable devices has been increasing recently. A strain sensor is required in various wearable devices. With respect to such devices, studies on resistance changes in strain sensors using flexible materials are in progress. However, the resistance of the rest area in a strain sensor should not change according to the applied strain. So, an electrode with resistance to stretching, bending, and torsion is required in such strain sensors. Tension, bending, and torsion can be realized through structural shape control, rather than by using flexible materials. Further, such an electrode that maintains electrical properties has been developed and manufactured. This electrode can be used in various applications such as foldable devices, e-papers, batteries, and multifunctional wearable devices.

• Journal of IKEEE
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• v.22 no.1
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• pp.193-196
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• 2018

In this study, we investigated the reliability of anisotropic conductive paste (ACP) and anisotropic conductive films (ACF), which are anisotropic conductive adhesives, applied to automotive touch panels. Adhesive material is also important as a key factor in assembling the touch panel. In order to measure the resistance change of the parts in two kinds of high temperature test, the reliability of the two types of anisotropic conductive adhesives was compared and evaluated through the results of the resistance change. For 615 hours of reliability testing, the anisotropic conductive film exhibited a higher stability in a high temperature environment than the anisotropic conductive paste.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.355-357
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• 2004

In this paper, to calculate accurate remaining volume, it presents how to figure out nickel-cadmium battery algorithm. A nickel-cadmium battery has widely been used in industrial field and to military. Recent high demands on the battery caused 'How to calculate accurate remaining volume is very important task to be solved. In this paper, it says it is useful using the terminal voltage change of the resistance that can be connected with the battery and the differentiation of the terminal voltage to calculate remaining volume of nickel-cadmium battery. And these can be used for volume inference data so that it is fuzzy based system which can be helpful to inference the remaining volume by the resistance of terminal voltage change. Because of electrochemical complexity, the volume calculating system is inferencing undirectly by experimentally built DB where as current the existing volume models are suffering to be adapted.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.12 no.4
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• pp.287-293
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• 2002

The unexpected failure of the induction motor makes the downtime of production, and the cost of the process cessation enormous. To reduce the downtime and increase the reliability of the motor, the vibration measurements for the fault detection have been used previously. Recently motor current signature analysis(MCSA) has been adapted for the fault detection and diagnosis of the motors. MCSA provides a powerful analysis tool for detecting the presence of mechanical and electrical faults in both the motor and driven equipment. In this paper, the fault severity of the rotor bar has been derived in terms of the resistance change which is calculated from the equivalent circuit model. Results show that the fault of the rotor can be easily detected and the measured value of the resistance change is verified by the detected fault from on-site tests using MCSA for the induction motors in an iron foundry.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.429-429
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• 2013

We present a systematic study of the electrical, optical and electromechanical properties of flexible graphene/metal grid hybrid transparent conductive electrodes using 4-point prove method, ultraviolet/visible spectrometer and inner/outer bending test system. The hybrid electrodes were synthesized by depositing a silver grid on a graphene surface. The sheet resistance of hybrid electrodes was as low as 30 Ω/square, while the transmittance was 90%. The electromechanical properties as a function of the change of bending radius were evaluated by measuring the change in resistance. The result will be presented in detail. We believe that these results will provide useful information for the flexible optoelectronic devices based on graphene transparent electrodes.

• Journal of Electrical Engineering and Technology
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• v.12 no.5
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• pp.1925-1933
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• 2017

The brushless DC motor's commutation torque ripple is caused by inconsistency in the rate of phase current change. Thus, a method that considers armature resistance is proposed to modulate phase current. The three-phase control strategy, which involves the "open-phase conduction, off-phase pulse width modulation, and maintained non-commutation phase" technique, is applied during commutation at full-speed segments of the motor. Changes in each phase current are analyzed theoretically by establishing mathematical model based on phase current to determine the relative difference among shutdown phase, duty, and motor operating parameters. The turn-on and turn-off phase current change rates are made to be consistent to ensure less non-commutation phase current ripple, then the torque ripple is inhibited. The simulation results show that the phase commutation current and torque ripple coefficient of the proposed method are reduced from 56.9% and 55.5% to 6.8% and 6.1%, respectively. In the experiment system, the pulsation coefficient of the motor phase current is reduced from 40.0% to 16.7% at low speed and 50.0% to 18.8% at high speed. The simulation and experimental results show that the proposed control method significantly inhibits commutation current and torque in the full section.