• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.230-233
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• 1999

Because Insulation material is play an important part for normal work of electricity equipment, the study is advanced, but as the voltage of electricity system is raising, we required that new lnsulation material. They have excellent specific against high stress, namely the study of insulation increase and prevention diagnosis of insulation degradation of Epoxy or XLPE and so on. In this thesis. I utilize image processing technique for effective inspection of insulation material degradation.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.712-715
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• 1999

Treeing has a profit to observe processing electrical breakdown because it gives degradation steps of insulation material by optical method. But, reappearance properly of treeing is not so good and precise quantization of tree growth is not so easy because tree Patterns are very complicate. The study on tree growth using image processing is predicted to precision of tree degradation and possible to quality measurement of tree pattern. In this paper, degradation steps are analyzed by image processing, therefore precision and realiability of tree growth are increased. Also, processing of tree degradation is quantized by fractal.

• Proceedings of the IEEK Conference
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• 2000.06b
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• pp.322-325
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• 2000

N-channel poly-Si TFT, Processed by Solid Phase Crystalline(SPC) on a glass substrate, has been investigated by measuring its electrical properties before and after electrical stressing. It is observed that the threshold voltage shift due to electrical stress varies with various stress conditions. Threshold voltages measured in 1.5$\mu\textrm{m}$ and 3$\mu\textrm{m}$ poly-Si TFTs are 3.3V, 3.V respectively. With the threshold voltage shia the degradation of transconductance(G$\_$m/) and subthreshold swing(S) is also observed.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.9
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• pp.2314-2333
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• 2023

It is significant to predict the performance degradation of complex electromechanical systems. Among the existing performance degradation prediction models, belief rule base (BRB) is a model that deal with quantitative data and qualitative information with uncertainty. However, when analyzing dynamic systems where observable indicators change frequently over time and working conditions, the traditional belief rule base (BRB) can not adapt to frequent changes in working conditions, such as the prediction of aeroengine performance degradation considering working condition. For the sake of settling this problem, this paper puts forward a new hidden belief rule base (HBRB) prediction method, in which the performance of aeroengines is regarded as hidden behavior, and operating conditions are used as observable indicators of the HBRB model to describe the hidden behavior to solve the problem of performance degradation prediction under different times and operating conditions. The performance degradation prediction case study of turbofan aeroengine simulation experiments proves the advantages of HBRB model, and the results testify the effectiveness and practicability of this method. Furthermore, it is compared with other advanced forecasting methods. The results testify this model can generate better predictions in aspects of accuracy and interpretability.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.2 no.3
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• pp.191-193
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• 2002

Insulation aging diagnosis system provides early warning in regard to electrical equipment defects. Early warning is very important in that it can avoid great losses resulting from unexpected shutdown of the production line. For solving this problem, many researchers proposed a method that diagnose power plant by using partial discharge. In this paper, we design the intelligent sensor to diagnose insulation degradation state that uses a Microprocessor and Al. Proposed sensor has MCU that is used to diagnose insulation degradation and communicate with main IDD system. And we use a fuzzy model to diagnose insulation degradation.

• Journal of Electrical Engineering and Technology
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• v.6 no.1
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• pp.123-127
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• 2011

To clarify the relations of optical properties to the main factors responsible for the loss and damage of luminous efficacy, a 20 min turn-on/turn-off test for 2,000 h for a ceramic metal halide lamp is conducted. The corrosion rates of the arc tube wall and electrode are estimated based on thermal stress. Wall blackening is attributed to the tungsten being transported from the hot electrode tips to the relatively cold arc tube wall. Furthermore, the grain boundaries of the arc tube are changed by the degradation. Distortion of the electrode is observed, and the ignition and the driving voltage of the load both increase. Finally, the color rendering index and the color coordinates are changed after the degradation. The luminous flux and the intensity of the luminous distribution are decreased significantly.

• Transactions on Electrical and Electronic Materials
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• v.15 no.6
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• pp.348-352
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• 2014

In light of the sure protection function, the most important factors of a varistor are the clamping voltage ratio and degradation characteristics. The degradation characteristics of Pr/Co/Cr/Er co-doped zinc oxide varistors were investigated by impulse currents (0.4~2.1 kA) stress for the specified content of $Er_2O_3$ (0.5 and 2.0 mol%). The varistor doped with 2.0 mol% $Er_2O_3$ exhibited the best clamp characteristics, with the clamp voltage ratio (K) in the range of K = 1.63~1.88 at the impulse currents of 5-50 A. However, the varistor doped with 0.5 mol% exhibited excellent electrical stability, with variation rates for the breakdown field, for the nonlinear coefficient, and for the leakage current density of -6.9%, -12.6%, and -14.3%, respectively, after application of an impulse current of 2.1 kA. In contrast, the varistor doped with 2.0 mol% was destroyed after application of an impulse current of 1.2 kA.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.43 no.7
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• pp.1121-1127
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• 1994

The accelerated degradation phenomena in amorphous silicon thin film transistors due to both electrical stress and visible light illumination under the elevated temperature have been investigated systematically as a function of gate bias, light intensity, and stress time. It has been found that, in case of electrical stress, the thrshold voltage shifts of a-Si:H TFT's may be attributed to the defect creation process at the early stage, while the charge trapping phenomena may be dominant when the stressing periods exceed about 2 hours. It has been also observed that the degradation in the device characteristics of a-Si:H TFT's is accelerated due to multiple stress effects, where the defect creation mechanism may be more responsible for the degradation rather than the charge trapping mechanism.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.831-834
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• 2002

Several companies in the world are marketing superconducting wires, films and bulks. High-Tc superconducting systems using these superconductors are begun to commercialize. For the successful realization or commercialization of superconducting system used Bi-2223 wires, the database on the degradation of critical current is essentially needed. In this paper, the electrical degradation of a Bi-2223 wires is measured. The electrical degradation rate was measured after the certain time of continuous current transportation. Specimens have the length of 190cm and double-pancakes coil have the length of 10m were tested. Tested Bi-2223 wires are commercialized product has 115A of Ic. When the transportation current was 95% of Ie, the degradation of Ic was appeared after 5 hours of transportation time. When the transferred current is enough larger than Ic, Bi-2223 double pancake is damaged seriously.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.05c
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• pp.25-28
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• 2001

The objectives of this paper are to demonstrate the electrical degradation phenomena with Si atom's behaviors in the grainboundary of semiconducting ZnO ceramics. The ZnO ceramic devices used in this investigation were fabricated by standard ceramic techniques. Especially, $SiO_2$ were added to analyze the degradation characteristics with Si and sintered in oxygen ambient at $1300^{\circ}C$. The conditions of DC degradation test were $115{\pm}2^{\circ}C$ for 13h. Using XRD and SEM, the phase and microstructure of samples were analyzed respectively. E-J analysis was used to determine $\alpha$. Frequency analysis was accomplished to understand $R_g$ and $R_b$ at the equivalent circuit. Electrical stability improved as the amount of $SiO_2$ addition increased. This results were explain by the quantitative analysis and the line scanning method of EPMA.