• Journal of Electrical Engineering and Technology
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• v.9 no.2
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• pp.695-706
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• 2014

Partial discharge (PD) measurements have emerged as a dominant investigative tool for condition monitoring of insulation in high voltage equipment. But the major problem behind them the PD signal is severely polluted by several noises like White noise, Random noise, Discrete Spectral Interferences (DSI) and the challenge lies with removing these noise from the onsite PD data effectively which leads to preserving the signal for feature extraction. Accordingly the paper is mainly classified into two parts. In first part the PD signal is artificially simulated and mixed with white noise. In second part the PD is measured then it is subjected to the proposed denoising techniques namely Translation Invariant Wavelet Transform (TIWT). The proposed TIWT method remains the edge of the original signal efficiently. Additionally TIWT based denoising is used to suppress Pseudo Gibbs phenomenon. In this paper an attempt has been made to review the methodology of denoising the PD signals and shows that the proposed denoising method results are better when compared to other wavelet-based approaches like Fast Fourier Transform (FFT), Discrete Wavelet Transform (DWT), by evaluating five different parameters like, Signal to noise ratio, Cross-correlation coefficient, Pulse amplitude distortion, Mean square error, Reduction in noise level.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1996.06a
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• pp.33-38
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• 1996

A multi-media binary DS/CDMA system with variable processing gain and coherent correlation receivers are considered under additive white Gaussian noise channels. Two types of information sources with different rates and transmitting powers are assumed to be transmitted simultaneously in the same channel. Average signal-to-noise ratios at the correlation receiver outputs for each type of information sources are analytically derived as functions of discrete partial cross-correlations between spreading code sequences. The analysis is expected to provide analytical tools for use in preliminary system design and spreading code selection.

• Clinics in Shoulder and Elbow
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• v.21 no.2
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• pp.67-74
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• 2018

Background: Fatty degeneration of rotator cuff is a well-known predictor of postoperative outcome. The purpose of this study was to evaluate the clinical features of rotator cuff tears involving subscapularis, and investigate whether fatty degeneration quantified from only the upper subscapularis correlates better with clinical outcomes than quantified from the whole subscapularis. Methods: We retrospectively analyzed 315 consecutive patients who underwent arthroscopic repair for rotator cuff tears involving subscapularis with a minimum follow-up of 1 year. Preoperative and postoperative visual analogue score for pain, range of motion and functional scores were assessed. Integrity of the repaired tendon was assessed at the 1-year follow-up with either magnetic resonance imaging or ultrasonography. Results: The mean Goutallier grade of whole cross-section was significantly lower than that of upper cross-section (1.59 vs. 1.71, p<0.05), but significantly higher than that of lower cross-section (1.59 vs. 1.01, p<0.05). In analysis of 37 re-tears, the occupancy of severe fatty degeneration in upper cross-section was 86.5%, which was significantly higher than that seen in whole cross-section (56.8%, p<0.05). We calculated the cut-off tear size for prediction of re-tears as 19.0 mm for retraction and 11.0 mm for superior-inferior. The cut-off Goutallier grade was 2.5 for both whole and upper cross-sections, but area under the curve was greater in the upper cross-section than the whole (0.911 vs. 0.807). Conclusions: As fatty degeneration of upper subscapularis demonstrated a more distinct spectrum than whole subscapularis, we suggest that measuring fatty degeneration of upper subscapularis can be a more useful method to predict clinical prognosis.

• Korean Journal of Occupational Health Nursing
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• v.26 no.1
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• pp.40-46
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• 2017

Purpose: The purpose of this study was to investigate the mediating effect of resilience on the relationship between emotional labor and happiness of clinical nurses. Methods: A descriptive, cross-sectional study was conducted with 224 clinical nurses who had one or more years of clinical experiences from four general hospitals in D city in Korea. Data collected from the survey using self-reported questionnaires were analyzed by t-test, one-way ANOVA, Pearson's correlation coefficients, and multiple regression analysis using IBM SPSS statistics 21.0 program. Results: There were statistically significant correlations among variables; a negative correlation between happiness and emotional labor, a positive correlation between happiness and resilience, and a negative correlation between emotional labor and resilience. Meanwhile, resilience had a partial mediating effect on the relationship between emotional labor and happiness. That is, resilience can play an important role between emotional labor and happiness of clinical nurses as a mediator. Conclusion: Considering the findings of this study, developing programs that can improve resilience of clinical nurses who experience emotional labor are needed to increase their level of happiness.

• Bulletin of the Korean Chemical Society
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• v.32 no.5
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• pp.1604-1612
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• 2011

We developed three-dimensional quantitative structure activity relationship (3D-QASR) models for 17 adamantyl derivatives as P-glycoprotein (P-gp) inhibitors. Eighteen different partial charge calculation methods were tested to check the feasibility of the 3D-QSAR models. Best predictive comparative molecular field analysis (CoMFA) model was obtained with the Austin Model 1-Bond Charge Correction (AM1-BCC) atomic charge. The 3D-QSAR models were derived with CoMFA and comparative molecular similarity indices analysis (CoMSIA). The final CoMFA model ($q^2$ = 0.764, $r^2$ = 0.988) was calculated with an AM1-BCC charge and electrostatic parameter, whereas the CoMSIA model ($q^2$ = 0.655, $r^2$ = 0.964) was derived with an AM1-BCC charge and combined steric, electrostatic, hydrophobic and HB-acceptor parameters. Leave-five-out (LFO) cross-validation was also performed, which yielded good correlation coefficient for both CoMFA (0.801) and CoMSIA (0.656) models. Robustness of the developed models was checked further with 1000 run bootstrapping analyses, which gave an acceptable correlation coefficient for CoMFA (BS-$r^2$ = 0.997, BS-SD = 0.003) and CoMSIA (BS-$r^2$ = 0.996, BS-SD = 0.018).

• Bulletin of the Korean Chemical Society
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• v.34 no.12
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• pp.3553-3558
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• 2013

The three dimensional-quantitative structure activity relationship (3D-QSAR) studies on chemical features of pyridine-2-amines in the external region of c-Met active site (ER chemical features of pyridine-2-amines) were conducted by docking, comparative molecular field analysis (CoMFA), and topomer CoMFA methods. The CoMFA model obtained the partial least-squares (PLS) statistical results, cross-validated correlation coefficient ($q^2$) of 0.703, non cross-validated correlation coefficient ($r^2$) of 0.947 with standard error of estimate (SEE) of 0.23 and the topomer CoMFA obtained $q^2$ of 0.803, $r^2$ of 0.940, and SEE of 0.24. Further, the test set was applied to validate predictive abilities of models, where the predictive $r^2$ ($r{^2}_{pred}$) for CoMFA and topomer CoMFA models were 0.746 and 0.608, respectively. Each contribution of ER chemical features of pyridine-2-amines to the inhibitory potency showed correlation coefficients, $r^2$ of 0.670 and 0.913 for two core parts, 3-(benzo[d]oxazol-2-yl)pyridine-2-amine and 3-(1-(2,6-dichloro-3-fluorophenyl)ethoxy) pyridine-2-amine, respectively, with corresponding experimental $pIC_{50}$.

• Korean Journal of Culture and Social Issue
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• v.27 no.4
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• pp.411-434
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• 2021

The purpose of this research was to examine the discrimination between grit and passion; and to compare the relationship between grit and passion between eastern and western culture. The participants were 208 Korean and 251 American undergraduates. Multiple-group factor analysis confirmed the model of four (consistency of interest, perseverance of efforts, harmonious passion, and obsessive passion) factors by configural invariance and partial measurement invariance. Also we found positive correlation between consistency of interest and harmonious passion as well as negative correlation between consistency of interest and obsessive passion in the American sample. However, the correlation between grit(consistency of interest, perseverance of efforts) and passion(harmonious passion, obsessive passion) was not significant in the Korean sample. The results suggest that grit is not accompanied by passion among Korean university students. Findings empirically highlight the distinctiveness of grit and passion and the possibility of cultural differences in grit and passion, which were usually discussed western cultures.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.1
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• pp.19-23
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• 2000

Partial discharges(PD)in air insulated electric power apparatus often lead to deterioration of solid insulation by electron bombardments and electrochemical reaction. The PD caused to reduce the life time of power apparatus and to increase power losses. Thus understanding and classification of PD patterns in air are very important to discern sources of PD. In this paper, PD in air by using statistical methods was investigated. We classified air discharges, corona, surface discharges and cavity discharges by Kohonen network. For classification of PD patterns, we used statistical operators and parameters such as skewness$(S^+,\; S^-),\; kurtosis(K^+, K^-),\; mean phase(AP^+, AP^-)$, cross-correlation factor(CC) and asymmetry derived from the mean pulse-height phase distribution$(H_{avg}(\phi))$, the max pulse-height phase distribution $(H_{qmax}(\phi))$, the pulse count phase distribution $(H_n(\phi))$ and the pulse height vs. Repetition rate $(H_q(n))$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.704-707
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• 1999

Partial discharge(PD) in air insulated electric power systems is responsible for considerable power lossesfrom high voltage transmission lines. PD in air often leads to deterioration of insulation by the combined action of the discharge ions bombarding the surface and the action of chemical compounds that are formed by the discharge and may give rise to interference in ommunication systems. PD can indicate incipient failure. Thus understanding and classification of PD in air is very important to discern source of PD. In this paper, we investigated PD in air by using statical method. We classified air discharge with corona, surface discharge and cavity discharge by source of discharge. we used the mean pulse-height phase distribution $H_{qmean}(\psi)$, the max pulse-height phase distribution $H_{qmax}(\psi)$ , the pulse count phase distribution $H_n(\psi)$ and the max pulse height vs. repetition rate $H_{q}(n)$ for analysis PD pattern. We used statistical operators, such as skewness(S+. S-1, kurtosis(K+, K-), mean phase(AP+. AP-), cross-correlation factor(CC) and asymmetry from the distribution.

• Journal of the Korean Chemical Society
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• v.42 no.2
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• pp.156-160
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• 1998

Probe diffusion with latex particles in two different types of chemically cross linked gel has been studied. The diffusion of particles in silica gel is decreased by decreasing the gel correlation length but the particles' diffusion in the acrylamide gel still shows the heterogeneity of the gel. By increasing the contents of the gel network the silica gel makes a more homogeneous and compact structure than that of acrylamide gel which has partial heterodyning. Dynamic light scattering study with the probe particles in two different gels reveals the heterogeneity of the gel network. The latex particles trapping in the gel has been investigated by using non-ergodic concepts.