• Communications for Statistical Applications and Methods
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• v.15 no.3
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• pp.451-464
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• 2008

Six sigma is the rating that signifies "best in clas", with only 3.4 defects per million units or operations. Higher sigma quality level is generally perceived by customers as improved performance by assigning a correspondingly higher satisfaction score. The process capability indices and the sigma level $Z_{st}$ have been widely used in six sigma industries to assess process performance. Most evaluations on process capability indices focus on point estimates, which may result in unreliable assessments of process performance. In this paper, we consider statistical inference for process capability indices $C_p$, $C_{pk}$ and $C_{pm}$. Also, we study better testing procedure on assessing sigma level $Z_{st}$ and capability index $C_{pm}$, for practitioners to use in determining whether a given process is capable. The proposed method is easy to use and the decision making is more reliable. Whether a process is clearly normal or nonnormal, our bootstrap testing procedure could be applied effectively without the complexity of calculation. A numerical result based on our proposed method is illustrated.

• Tuberculosis and Respiratory Diseases
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• v.54 no.4
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• pp.395-402
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• 2003

Background : Patients with chronic obstructive pulmonary disease (COPD) are at increased risk for osteoporosis, which has implications for mobility and even mortality. The goal of this pilot study was to evaluate bone mineral density (BMD) and risk factors for osteoporosis in a limited number of men with COPD. Methods : We checked BMD, $FEV_1$(% of predicted) and investigated risk factors for osteoporosis in 44 male patients with COPD who visited our hospital from January to August 2002. Results : Mean(${\pm}$) age was $69{\pm}9$ yrs, body mass index(BMI) $21{\pm}3kg/m^2$, $FEV_1$ $50{\pm}18%$ of predicted, lumbar spine T-score $-3.0{\pm}1.2$, lumbar spine Z-score $-2.0{\pm}1.2$, and lumbar spine BMD $0.76{\pm}0.13g/cm^2$. Osteoporosis(T-score below -2.5) was present in 27 patients(61.4%) and osteopenia(T-score between -1 and -2.5) in 17(38.6%). None of the patients had normal BMD. There was no relationship between BMD and $FEV_1$(% of predicted). There were significant differences in smoking, alcohol consumption, exercise, cumulative steroid dose, BMI and BMD among the three groups according to $FEV_1$(% of predicted) (group1 : ${\geq}65%$, group2 : 50-64%, group3 : ${\leq}49%$), except age. However, there were no significant differences in these variables between the osteopenia and osteoporosis groups, except BMI. Linear Regression(Stepwise) analysis showed that lumbar BMD was correlated with BMI & exercise. Conclusion : BMD is significantly reduced in men with COPD. There was no relationship between BMD and pulmonary function.

• Journal of Microbiology and Biotechnology
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• v.15 no.5
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• pp.1054-1059
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• 2005

An extracellular protease was identified from Bacillus subtilis KCCM 10257 by N-terminal sequencing and mass spectral analysis. The molecular mass of the extracellular protease was estimated to be 28 kDa by SDS-PAGE. Sequencing of the N-terminal of the protease revealed the sequence of A(G,S,R)QXVPYG(A)V(P,L)SQ. The N-terminal sequence exhibited close similarity to the sequence of other proteases from Bacillus sp. A mass list of the monoisotopic peaks in the MALDI-TOF spectrum was searched after peptide fragmentation of the protease. Six peptide sequences exhibiting monoisotopic masses of 1,276.61, 1,513.67, 1,652.81, 1,661.83, 1,252.61, and 1,033.46 were observed from the fragmented protease. These monisotopic masses corresponded to the lytic enzyme L27 from Bacillus subtilis 168, and the Mowse score was found to be 75. A doubly charged Top product (MS) at a m/z of 517.3 exhibiting a molecular mass of 1034.6 was further analyzed by de novo sequencing using a PE Sciex QSTAR Hybrid Quadropole-TOF (MS/MS) mass spectrometer. MS/MS spectra of the Top product (MS) at a m/z of 517.3 obtained from the fragmented peptide mixture of protease with Q-star contained the b-ion series of 114.2, 171.2, 286.2, 357.2, 504.2, 667.4, 830.1, and 887.1 and y-ion series of 147.5, 204.2, 367.2, 530.3, 677.4, 748.4, 863.4, and 920.5. The sequence of analyzed peptide ion was identified as LGDAFYYG from the b- and y-ion series by de novo sequencing and corresponded to the results from the MALDI-TOF spectrum. From these results the extracellular protease from Bacillus subtilis KCCM 10257 was successfully identified with the lytic enzyme L27 from Bacillus subtilis 168.

• The Journal of Korean Academic Society of Nursing Education
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• v.28 no.3
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• pp.248-258
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• 2022

Purpose: This study aimed to identify the mediating effect of professional self-concept on the relationship between nurse's image and career identity, and between satisfaction with the nursing major and the career identity of nursing students. Methods: This study utilized a descriptive methodology, and 205 nursing students attending three universities in Busan Metropolitan City participated in it. Data were collected from self-reported questionnaires between March 26 and April 30, 2022. Data were analyzed with descriptive statistics, an independent t-test, analysis of variance, Pearson's correlation coefficient, and simple and multiple regression using the IBM SPSS 22.0 program and Sobel test. Results: The mean score of career identity was 2.92±0.57 out of a possible 4. Career identity showed a significantly positive correlation with nurse's image (r=.32, p<.001), satisfaction with major (r=.47, p<.001), and professional self-concept (r=.32, p<.001). Additionally, professional self-concept had a partial mediating effect on the relationship between nurse's image (Z=2.44, p<.001), satisfaction with major (Z=2.35, p<.001), and career identity. Conclusion: The results of the study show professional self-concept had a mediating effect on the relationship between nurse's image, satisfaction with the nursing major, and career identity. Based on the study's results, career identity education programs for nursing students need to include nursing image, satisfaction with major, and professional self-concept.

• Analytical Science and Technology
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• v.20 no.1
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• pp.78-83
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• 2007

To perform proficiency test for determining anti-impotence drug-like compounds in food, interlaboratory test has been done. Targets were 6 such as sildenafil, tadalafil, vardenafil, homosildenafil, hydroxy-homosildenafil and pseudo-vardenafilI. Total 13 institutes were participated and all is in charging of food analysis. To do double blind test, the reference materials were made as 13 different ginseng drink samples and each sample had random 3 targets. By the official method for anti-impotence drug-like compounds in food code, sample was just diluted in water, extracted in organic solvents, determined by HPLC/UV and then confirmed by LC/MS. The analytical duration was 60 days after receiving sample. Ten out of 13 institutes were satisfied by evaluation of Z-score and RSZ according to the regulation for managing analytical quality assurance.

• Journal of Korean Society for Atmospheric Environment
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• v.14 no.6
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• pp.631-642
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• 1998

Fall-out particles were collected by the modified British deposit gauges at 35 sampling sites in Suwon area from January to November, 1996. Twenty chemical species (Al. Ba, Cd, Cr, K, Pb, Sb, Zn, Cu, Fe, Ni, V, F-, Cl-, NO3-, 5042-, Na+, NH4+, Mg2+, and Ca2+) were analyzed by AAS and If. The purposes of this study were to estimate qualitatively various emission sources of the fell-out particle by applying multivariate statistical techniques such as factor analysis, multiple regression analysis, and discriminant analysis. During the study, outlier sites were determined by a z-score method. Cl-, Na+, Mg2+, and SO42- were highly correlated due to their common marine related source. Wind speed was the most influential factor for the deposition fluxes of the particle itself and all the chemical species as well. When applying the factor analysis, 8 source patterns were qualitatively obtained, such as marine source, soil source, oil burning source, Cr related source, tire source, Cd related source, agriculture source, and F- related source. As a result of the multiple regression analysis, we could suggest that some chemical compounds may possibly exist in the form of CaSO4, NaN03, NaCl, MgC12, (NH4)2SO4, NaF, and CaCl2 in the fall-out particles. Finally, spatial and seasonal classification study performed by a discriminant analysis showed th.at SO42-, Ca2+, Cl-, and Fe were dominant in the group of spatial pattern; however, SO42-, Cl-, Al, and V were in the group of seasonal pattern.

• Journal of Oriental Neuropsychiatry
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• v.27 no.3
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• pp.169-184
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• 2016

Objectives: To investigate the neurophysiological effect of acupuncture treatment on insomnia patients using quantitative electroencephalography (QEEG) and standardized Low Resolution Brain Electromagnetic Tomography method (sLORETA).Background: Insomnia is one of the commonly encountered symptoms in primary medical care. Recent studies of acupuncture for insomnia reported that the acupuncture groups showed significant improvements compared with the control groups. However, the neurophysiological mechanism of acupuncture in the treatment of insomnia has not been revealed and a few studies have measured the effect of acupuncture treatment using QEEG.Methods: Participants who had some problems in initiating or maintaining sleep, or had non-restorative sleep for more than 3 days a week and ISI scores above 8 and below 21 were treated by acupuncture for 2 weeks (3 times a week, total 6 times). We assessed the effectiveness of acupuncture for insomnia by the PSQI (Pittsburgh Sleep Quality Index) at baseline and at 2 weeks after the end of treatment (4th week). Also, we performed EEG and analysed the EEG data at baseline and at the end of treatment (2nd week) on the linked ears montage using the Neuroguide software program and sLORETA.Results: Thirty-two participants were enrolled and 2 participants dropped out because of personal reasons. Among the 30 participants, EEGs of 12 participants were included in the analysis of QEEG and sLORETA. Total score on the ISI and PSQI was significantly decreased after acupuncture treatment. The number of electrodes exceeding the range of 90% (±1.65) or 95% (±1.96) in the z scored absolute power of beta was significantly decreased after acupuncture treatment. There was no significant change in brain activation between pre- and post-acupuncture using sLORETA.Conclusions: The deviation of absolute power compared to the normative database was significantly decreased after acupuncture treatment in the alpha and beta ranges. Therefore, we suggest that acupuncture treatment for insomnia might be effective through the central nervous system especially in the brain. There are many limitations to drawing any conclusion. Further studies are needed in the future to overcome these limitations.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.4 no.1
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• pp.63-70
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• 2001

Purpose: The aim of this study is to evaluate the effective role of living-related liver transplantation (LRLT) on posttransplant linear growth in children. Methods: Thirty six children were enrolled who received LRLT at Asan Medical Center from December, 1994 to February, 1999 and showed more than one-year postoperative survival. Mean height standard deviation score (zH) was analyzed according to medical records including heights during pretransplant and posttransplant follow-up periods. Results: zH of total children showed significant linear growth after LRLT from -1.58 to 0.33 at 24 posttransplant month (p<0.05). zH in children under 6 years of age, to exclude the effect of adolescent linear growth spurt, showed increment in height (p<0.05). Linear growth of children with liver cirrhosis improved and that with fulminant hepatitis was matained same. While stunted children (mean zH=-2.30) achieved good catch-up growth after transplantation, children with normal growth remained same. Children with significant hepatic dysfunction after LRLT such as chronic rejection or posttransplant lymphoproliferative disorder showed retarded posttrasplant linear growth. There was no statistical difference according to the type of immunosuppressants. Conclusion: LRLT resulted in adequate or catch-up linear growth in children with acute, chronic and metabolic liver disease. Successful LRLT suggested to be a promising option not only in long term survival but also in normal linear growth.

• Sleep Medicine and Psychophysiology
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• v.27 no.2
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• pp.56-66
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• 2020

Objectives: In this study, the clinical characteristics of OSA patients and the quality of life before and after CPAP use were compared to determine the degree of improvement in quality of life according to CPAP use. Methods: Age, sex, height, weight, body mass index, Epworth Sleepiness Scale, Modified Mallampatti Score, Montreal Cognitive Assessment-Korean, and Pittsburgh Sleep Quality Index were compared between men and women through medical records. To understand the degree of improvement in quality of life resulting from use of CPAP, a personal telephone call was made to compare the VAS scores for quality of life before and after CPAP use. Results: In height (HT) (Z = -4.525, p < 0.001), weight (BW) (Z = -2.844, p < 0.05), sleep quality (PSQI) (Z = -2.671, p < 0.05), and arousal index (AI) (Z = -2.105, p < 0.05), there was a difference between men and women (p < 0.05). There was no difference in the remaining variables. Cross-analysis (Chi-square test) confirmed a difference between severity and sex of OSA. It has been found that there is no statistically significant order in size according to level-specific severity of OSA for PreCPAP QOL, PostCPAP QOL, CPAPUse Months, and CPAP4Hr/d (%) (p > 0.05). The difference between AHI before and after CPAP was 36.48 ± 21.54 (t = 11.609, p < 0.001) and the difference between QOL before and after CPAP was -25.43 ± 22.06 (t = -7.901, p < 0.001), both of which were significant (p < 0.001). Conclusion: Among OSA patients, there were differences in height (HT), weight (BW), sleep quality (PSQI), arousal index (AI), and severity of OSA between men and women, but the quality of life before and after CPAP was different. However, there was no difference between men and women in quality of life before and after CPAP. In addition, quality of life in OSA patients improved after using CPAP.

• Clinical and Experimental Pediatrics
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• v.51 no.6
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• pp.629-633
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• 2008

Purpose : This study was designed to investigate normal domestic values for the diameter of the left main coronary artery (LCA), the left anterior descending coronary artery (LAD) and the right coronary artery (RCA). These data are necessary to define dilatation of coronary arteries in Kawasaki disease cases. Methods : Study subjects were 43 normal healthy children whose ages ranged from 3 months to 6 years. They children visited Konkuk University hospital for echocardiograph examination between March 2005 and November 2007. Measurements of coronary arterial diameters at each branch were done by off-line analyses of recorded images. Simple regression analysis of each the measurements were performed using the body size (body surface area, etc.) as the independent variable. Results : Body surface area was significantly related to the diameters of LCA ($r^2=0.20$, P=0.0038), of LAD ($r^2=0.41$, P<0.0001), and of RCA ($r^2=0.30$, P=0.0002). In the regression model, the estimates of the y-intercept were 1.703, 1.058, and 1.007; the estimates of the regression coefficient were 0.971, 1.175, and 1.177; and the estimates of the standard deviation were 0.315, 0.221, and 0.282 with respect to the three coronary arteries. Conclusion : A the linear regression model of the diameters of three coronary arteries adjusted for body surface area was produced. With these results, the Z-score calculation of the diameter of three coronary arteries, based on normal domestic data, will be possible.