• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.186-189
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• 2004

Sensor used by semiconductor process produced an MAP sensor and applied to several industry. Among those sensors divided as transducer which convert physical quantity into electrical value, piezoresistive type sensor has been studied for the properties and sensitivity of piezoresistor. In this paper, the variation of seismic mass which have been functioned as actuator moving the cantilever beam analyzed the effect on distribution of resistance change ratio and supposed the optimal shape and position of piezoresistor. The resulting are following; According to the increment of seismic mass size, the value of resistance change ratio decreased caused by improve the stiffness. Y directional piezoresistor is formed in spot of 100 m apart from cantilever edge and length of that is 800$\mu$m. To increase the sensitivity, piezoresistor is made as n-type and x-direction.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.115-118
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• 2003

The sensor at liquid nitrogen temperature showed the increase of electrical resistance by applying magnetic field. Actually, the voltage drop across the sensor was changed from zero to a value more than $100\;{\mu}V$ by the applied magnetic field. The change of electrical resistance depended on magnetic field. The sensitivity of this sensor was $2.9\;{\Omega}/T$. The sensing limit was about $1.5{\times}10^{-5}\;T$. The increase of electrical resistance by the magnetic field was ascribed to a modification of the Josephson junctions due to the penetrating magnetic flux into the superconducting material. Considering the observed properties of the superconductor with trapped magnetic flux, a magnetic sensor was fabricated to detect simultaneously both the intensity and the direction of the magnetic field.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.5
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• pp.429-434
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• 2003

The magnetic field sensor was fabricated with superconducting ceramics of BiPbSrCaCuO system. The sensor at liquid nitrogen temperature showed the increase of electrical resistance by applying magnetic field. Actually, the voltage drop across the sensor was changed from zero to a value more than 100 $\mu\textrm{V}$ by the applied magnetic field. The change of electrical resistance depended on magnetic field. The sensitivity of this sensor was 2.9 $\Omega$/T. The sensing limit was about 1.5${\times}$10$\^$-5/ T. The increase of electrical resistance by the magnetic field was ascribed to a modification of the Josephson junctions due to the penetrating magnetic flux into the superconducting material. Considering the observed properties of the superconductor with trapped magnetic flux, a magnetic sensor was fabricated to detect simultaneously both the intensity and the direction of the magnetic field.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.252-254
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• 2003

A magnetic field sensor is fabricated with superconducting ceramics system. The sensor at liquid nitrogen temperature shows the increase in electrical resistance by applying magnetic field. Actually, the voltage drop across the sensor is changed from zero to a value more than $100{\mu}V$ by the applied magnetic field. The change in electrical resistance depends on magnetic field. The sensitivity of this sensor is 2.9 ohm/T. The increase in electrical resistance by the magnetic field is ascribed to a modification of the Josephson junctions due to the penetrating magnetic flux into the superconducting material.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.3
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• pp.173-178
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• 2009

We have investigated the electrical properties of oxide metal thin film device. The device has been fabricated top-top electrode structure and its transport properties are measured in order to study the resistance change. Electrical properties with linear voltage sweep on a electrodes are used to show the variation of resistance of oxide metal thin film device. Fabricated oxide metal thin film device with MIM structure is changed from a low conductive Off-state to a high conductive On-state by the external linear voltage sweep. The $Si/SiO_2/MgO$ device is switched from a high resistance state to a low resistance state by forming. Consequently, we believe oxide metal is a promising material for a next-generation nonvolatile memory and other electrical applications.

• Bulletin of the Korean Chemical Society
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• v.33 no.9
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• pp.3033-3038
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• 2012

The hydrogen storage mechanism of graphite was studied by measuring the electrical resistance change. Graphite was expanded and activated to allow for an easy hydrogen molecule approach and to enlarge the adsorption sites. A vanadium catalyst was simultaneously introduced on the graphite during the activation process. The hydrogen storage increased due to the effects of expansion, activation, and the catalyst. In addition, the electrical resistance of the prepared samples was measured during hydrogen molecule adsorption to investigate the hydrogen adsorption mechanism. It was found that the electrical resistance changed as a result of the easy hydrogen molecule approach, as well as of the adsorption process and the catalyst. It was also notable that the catalyst improved not only the hydrogen storage capacity but also the speed of hydrogen storage based on the response time. The hydrogen storage mechanism is suggested based on the effects of expansion, activation, and the catalyst.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.12
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• pp.1694-1699
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• 2013

Frequency accelerated partial discharge resistance (PDR) aging of epoxy/layered silicate nanocomposite with 1.5wt % additions of layered silicate was investigated in comparison with that of epoxy without layered silicate in terms of PD(partial discharge) erosion depth. It was found that the change in the erosion depth is far smaller in specimens with layered silicate than those without layered silicate nano particles. Frequency acceleration can be done from 60Hz to 1000Hz. But the depth of erosion is less proportional to frequency. Acceleration factor is almost 2 times between 500Hz and 1000Hz, but it is much less than about 8.3 times between 60Hz and 500Hz. This superior PD resistance is caused by the presence of nanofillers, anano-effect due to closely packed nanofillers, and strong chemical bonds at layered silicate nanofillers /resin interfaces.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.32 no.5
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• pp.407-412
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• 2019

In this paper, the changes in the electrical characteristics (arc energy, contact resistance, and bouncing phenomenon) due to the deterioration of the contact are analyzed. The results are generally consistent and can be analyzed for contact deterioration. The results of the experiment demonstrate that the arc energy is linearly related to the current when the contact samples and the voltage conditions are the same. The contact resistance varies due to multiple factors, but is generally within a certain range, and the contact deterioration can be determined. Contact stabilization can be detected by the decrease in the bouncing phenomenon due to deterioration (the change of the shape of the contact).

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.1
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• pp.27-32
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• 2017

In this paper, slot less type high-speed and compact motor was designed. it was selected through change of stator coil distribution for the optimal performance of the motor. In this paper, designed motor was expected to be very vulnerable to heat dissipation in a compact motor. Therefore, to ensure reliability in the design result, winding and permanent magnet damage caused by the losses of motor was analyzed by thermal analysis and demagnetization analysis. Using the result, whether motor burnout was confirmed by motor performance degradation and insulation breakdown.

• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.271-273
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• 2005

In this paper, The experiment is performed for using reinforced building of foundation as a down conductor and a substitutional earth electrode. It is shown that earth resistance is influenced by mortar block resistance and concrete resistance more than the change of the resistance which is about steel reinforcing volume in all of the mortar block model and concrete block model.