• The Transactions of the Korean Institute of Electrical Engineers D
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• v.55 no.4
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• pp.181-188
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• 2006

The purpose of this study is to predict the defibrillation success of a ventricular Fibrillation ECG signal using time-frequency analysis. During CPR, coronary perfusion pressure and electrocardiogram were measured. Parameters extracted from time-frequency domain were served as predictor of resuscitation success. Time frequency distribution(TFD) of ECG signals was estimated from the smoothed pseudo Wigner-Ville distribution(SPWVD). Median frequency, peak frequency, 1/f slope, frequency band ratios$(2{\sim}4Hz,\;4{\sim}6Hz,\;6{\sim}8Hz,\;8{\sim}10Hz,\;10{\sim}12Hz,\;12{\sim}15Hz)$ were extracted from each TFD as function of time. Paired t-test was used to determine the differences in ROSC and non-ROSC groups. In the statistical results, we selected four significant parameters - median frequency, 1/f slope, $2{\sim}4Hz$ band ratio, $8{\sim}10Hz$ band ratio. We made an attempt to predict defibrillation success by combining features extracted from time frequency distribution. Independent t-test was used to determine the differences ROSC and non-ROSC groups. Consequently, we selected four significant parameters-median frequency, 1/f slope, $2{\sim}4Hz$ band ratio, $8{\sim}10Hz$ band ratio. The relationship between coronary perfusion pressure and ECG parameters was analyzed with linear regression analysis. R-square value was 55%. 1/f slope and $8{\sim}10Hz$ band ratio had the significant relationship with coronary perfusion pressure.

• Journal of Korean Academy of Nursing Administration
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• v.5 no.1
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• pp.77-86
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• 1999

The purpose of this study is to look into nurse's legal duty and to analyze influencing factors, by reading through precedents in nursing-related malpractice cases. 157 clinic nurses and 40 head nurses who were working in 3 university hospitals in the area of Seoul and KyongKi province were surveyed with pre-set questionnaires which were based on 20 cases and to compare precedents with nurses' attitudes. Independent variables were demographic characteristics, job characteristics, experience and education, and personal characteristics. Dependent variables were the extents of understanding in their duty. To analyze the extent of duty understanding t-text. ANOVA, and multiple regression were performed according to the characteristics of each study subject. Main findings are as follows; 1. $X^2$ test was performed for each hospitals and job category. The existence of religion and job-related advisers were significantly different according to hospitals and job categories. The existences of the orientation for nursing, education, and meeting were significantly different according to hospitals. 2. The extent of duty understanding according to the subject characteristics was assessed by means of median. Each case was given the median. 12 cases(46%)out of 26 cases demonstrated the median of more than 6 showing high extent of understanding. 3. When $X^2$ test was performed. the extent of duty understanding was significantly different in the areas of marriage status. the existence of meetings. and the experience of having dispute. When multiple regression(stepwise method) was performed, above variables were not statistically significant. 4.As result of comparative analysis on precedents and nurse's attitudes. it is 4 cases that nurse's attitudes is more active than precedents and it is 9 cases that nurse's attitudes is more passive than precedents and it is 4 cases that nurse's attitudes is parallel with precedents. This study does not present statistical model which can integrate all the cases. The significance of this study is in that it generalized and assessed the nurses' understanding of duty based on nursing -care which was legally disputed and compared nurse's attitude with precedents.

• Communications for Statistical Applications and Methods
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• v.10 no.2
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• pp.535-543
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• 2003

A ranked set sample version of the sign test is proposed for testing hypotheses concerning the quantiles of a population characteristic by Kaur, et. al(2002). In this paper, we proposed the ranked set sample Wilcoxon signed rank test for quantiles under equal allocation. We obtain the asymptotic property and the asymptotic relative efficiencies of the proposed test statistic with respect to Wilcoxon signed rank test of simple random sample for quantiles under equal allocation. We calculate the ARE of test statistics, the proposed test statistic is more efficient than simple random sampling for all quantiles. The relative advantage of ranked set sampling is greatest at the median and tapers off in the tails.

• Journal of the Korean Data and Information Science Society
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• v.13 no.2
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• pp.271-284
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• 2002

In this paper we consider the robust inference for the parameter of linear regression model based on weighted least squares. First we consider the sequential test of multiple outliers. Next we suggest the way to assign a weight to each observation $(x_i,\;y_i)$ and recommend the robust inference for linear model. Finally, to check the performance of confidence interval for the slope using proposed method, we conducted a Monte Carlo simulation and presented some numerical results and examples.

• Journal of the Korean Statistical Society
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• v.33 no.2
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• pp.149-157
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• 2004

The stationarity is one of the most important properties of a time series. We propose robust sign tests for seasonal autoregressive processes to determine whether or not a time series is stationary. The proposed tests are robust to the outliers and the heteroscedastic errors, and they have an exact binomial null distribution regardless of the period of seasonality and types of median adjustments. A Monte-Carlo simulation shows that the sign test is locally more powerful than the tests based on ordinary least squares estimator (OLSE) for heavy-tailed and/or heteroscedastic error distributions.

• Journal of the Korean Institute of Telematics and Electronics
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• v.24 no.3
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• pp.493-503
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• 1987

Performances of some image restoration filters are compared and evaluated on SNR gain and subjective test. Test images used here are the GIRL and PLANT images corrupted by Gaussian, uniform, BSC, and impulse noise, respectively. Experimental results show that the scalar DCT-Wiener filter among them is comparatively superior to others in Gaussian and uniform noise. On the other hand, the median filter is much better than others in BSC and impulse noise.

• Journal of Periodontal and Implant Science
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• v.27 no.3
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• pp.479-493
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• 1997

There are various treatment methods including barrier membranes in attaining periodontal regeneration and regaining the function of destructed periodontal tissues due to periodontal disease. Barrier membranes consist of non-Resorbable and resorbable types such as Dura mater and $Guidor^{(R)}$ used in the treatment of intrabony defects and classII furcation defects have been shown to be effectively increased the amount of new bone and cementum.In our study we used premolars with class III furcation defects created by removing the bone 4mm apically from CEJ in adult dogs and placed resorbable membrane Dura mater and $Guidor^{(R)}$ for the test group and flap operation was carried out for the control groups. The effect of membrane on junctional epithelium, alveloar bone, cementum, and gingival connective tisssue in the regeneration and healing potential of periodontal tissues was evaluated and healing results were evaluated histologically and histometrically 8 weeks following the surgical procedure. 1. In the clinical observation, there was no exposure of furcation defects in the control group, whereas slight membrane exposure was noted in the test group. 2. New bone was formed up to the level of the notch in the control group, whereas in the test group new bone formation was observed above the level of the notch. 3. New cementum was formed in both groups of the experiment. 4. The connective tissue observed between the new cementum and new bone in the test group were functionally orientated, compared to the irregular formation of connective tissues found in the control group. 5. Root resorption or ankylosis was not observed in any of the groups 6. The mean and median of the control group were 4.31% and 2.23% and for the Dura mater group were 27.85% and 15.57% respectively. There was no significant difference between Dura mater and the control group. 7. The mean and median of the control group were 4.31% and 2.23% and for the $Guidor^{(R)}$ group were 37.27% and 37.19% respectively. There was a significant difference in these two groups(P$Guidor^{(R)}$ were 37.27% and 37.19%. There was no significant difference between the two test groups. Thus, by using Dura mater and Guidor in classIII furcation defects, the predictable amount of periodontal ligament and alveolar bone regeneration may result.

• The Journal of Korean Physical Therapy
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• v.33 no.5
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• pp.258-263
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• 2021

Purpose: Myofascial syndrome is a chronic muscle pain caused by repetitive motions with stress-related muscle tension. This study aimed to investigate the validity and reliability of the evidence for diagnosing myofascial pain syndrome in trapezius muscle using a pressure algometer and surface electromyography. Methods: The experiments were performed using a total of 10 subjects, and the target locations were determined by means of a pressure algometer in the right upper trapezius muscle. The part with the lowest pain value as the trigger point and the part with the highest pain value as the non-pain trigger point were selected for measuring the locations. The median frequency and average frequency were measured in those locations with electromyography. To check the muscle fatigue, the upper trapezius muscle was moved up and down for 2 seconds at 5-second intervals in 30 seconds. The measured values were evaluated using the independent paired t-test and MannWhitney U-test. Results: The median frequency at the non-trigger point (13.7) was significantly higher than that at the trigger point (7.3). Furthermore, the mean frequency (14.7) at the non-trigger point was significantly higher than that at the trigger point (6.3). Conclusion: The results showed the correlations between the trigger points of the muscle pain and frequency analysis of surface electromyography. Thus, this study may be possible to use as a diagnostic tool for myofascial pain syndrome.

• The Korean Journal of Pain
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• v.37 no.1
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• pp.34-40
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• 2024

Background: This study aimed to evaluate the efficacy of pulsed radiofrequency applied using transcutaneous electrodes in carpal tunnel syndrome (CTS). Methods: After randomization, the patients received two cycles of noninvasive pulsed radiofrequency (NiPRF), once weekly, or splinting (the control group) for three months. Clinical evaluations were recorded at baseline and weeks 4 and 8. The Boston Carpal Tunnel Syndrome Questionnaire (BCTQ) was used to determine the functional status and symptom severity. Results: Sixty-two patients were followed up for three months. There was no difference between the groups in the BCTQ scores before and after treatment. The NiPRF group found a significant difference between the BCTQ measurements at all time intervals (paired sample t-test; P < 0.001). In the splint group, there was a significant difference only between the basal-1st month and basal-3rd month (paired samples t-test; P < 0.001). The main effect of the time variable was statistically significant (ANOVA; P < 0.001), but the group variable was not. There was no correlation between the BCTQ results measured at any time and the electroneuromyelogragphy findings in either group. Conclusions: NiPRF effectively improves symptoms and functionality in patients with CTS for up to 3 months. Thus, NiPRF can be considered an easy, safe, and useful alternative treatment modality for CTS.

• Journal of the Korean Statistical Society
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• v.30 no.4
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• pp.679-691
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• 2001

Two truncated sequential tests are developed for the two-sample scale problem based on the usual Wilcoxon rank-sum statistic for two different dispersion indices - absolute median deviations, when the medians of the two populations X and Y are equal or known and sums of squared mean deviations, when the medians are either unknown or unequal. The first test is briefly called SWAMD test and the second SWSMD test. For the SWAMD test, the percentile points for both the one-sided and two-sided alternatives, (equation omitted) have been found by Wiener approximation and their values computed for a range of values of a and N; analytical expression for the power function has been derived through Wiener process and its performance studied for various sequential designs for exponential distribution. This test has been illustrated by a numerical example. All the results of the SWAMD test, being directly applicable to the SWSMD test, are not dealt with separately Both the tests are compared and their suitable applications indicated.