• Communications for Statistical Applications and Methods
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• v.16 no.4
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• pp.647-658
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• 2009

It is already known from the previous study that flood seems to have heavier tail. Therefore, to make prediction of future extreme label, some agreement of tail behavior of extreme data is highly required. The LH-moments estimation method, the generalized form of L-moments is an useful method of characterizing the upper part of the distribution. LH-moments are based on linear combination of higher order statistics. In this study, we have formulated LH-moments of five distributions useful in hydrology such as, two types of three parameter kappa distributions, beta-${\kappa}$ distribution, beta-p distribution and a generalized Gumbel distribution. Using LH-moments reduces the undue influences that small sample may have on the estimation of large return period events.

• The Korean Journal of Applied Statistics
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• v.31 no.3
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• pp.417-426
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• 2018

An alternative developmental toxicity test using mouse embryonic stem cell derived embryoid bodies has been developed. This alternative method is not to administer chemicals to animals, but to treat chemicals with cells. This study suggests the use of Discriminant Analysis, Support Vector Machine, Artificial Neural Network and k-Nearest Neighbor. Algorithm performance was compared with accuracy and a weighted Cohen's kappa coefficient. In application, various classification techniques were applied to cytotoxicity data to classify drug toxicity and compare the results.

• Journal of the Korean Magnetics Society
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• v.26 no.6
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• pp.219-225
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• 2016

In this study, for assessment of degenerative knee joint cartilage disease we acquired images by fat suppressed 3D spoiled gradient recalled (SPGR) and fat suppressed 3D $T2^*$ weighted imaging techniques. To do a quantitative evaluation, the knee joint cartilage was divided into medial femoral cartilage (MFC), medial tibial cartilage (MTC), lateral femoral cartilage (LFC), lateral femoral cartilage (LFC) and patella cartilage (Pat) to measure their respective signal intensity values, signal-to-noise ratio, and contrast-to-noise ratio. As for the measured values, statistical significance between two techniques was verified by using Mann-Whitney U-Test. To do a qualitative evaluation, two radiologists have examined images by techniques after which image artifact, cartilage surface, tissue contrast, and depiction of lesion distinguishing were evaluated based on 4-point scaling (1: bad, 2: appropriate, 3: good, 4: excellent), and based on the result, statistical significance was verified by using Kappa-value Test. 3.0T MR system and HD T/R 8ch knee array coil were used to acquire images. As a result of a quantitative analysis, based on SNR values measured by using two imaging techniques, MFC, LFC, LTC, and Pat showed statistical significance (p < 0.05), but MTC did not (p > 0.05). As a result of verifying statistical significance for measured CNR value, MFC, LFC, and Pat showed statistical significance (p < 0.05), while MTC and LTC did not show statistical significance (p > 0.05). As a result of a qualitative analysis, by comparing mean values for evaluated image items, 3D $T2^*$ weighted Image has indicated a slightly higher value. As for conformance verification between the two observers by using Kappa-value test, all evaluated items have indicated statistically significant results (p < 0.05). 3D $T2^*$ weighted technique holds a clinical value equal to or superior to 3D SPGR technique with respect to evaluating images, such as distinguishing knee joint cartilages, comparing nearby tissues contrast, and distinguishing lesions.

• Journal of the East Asian Society of Dietary Life
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• v.10 no.3
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• pp.245-251
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• 2000

This study was conducted to investigate the influence of different nutrient databases in estimating nutrient intake. A nutrient survey with Food Frequency Questionnaire containing 65 food items was conducted with 2,426 subjects over 30 years of age living in Yeonchon-gun, Kyungki province. The nutrient intakes were first estimated by using one (A) nutrient database which was based on the Korean Food Composition Table, 4th edition. With the other (B) nutrient database which was based on the Korean RDA(Recommended Dietary Allowances) 6th edition, it was reestimated and two resu1ts were compared. For most nutrients except carbohydrate, calcium, vitamin C and $eta$-carotene, mean nutrient intake level estimated from database B was significantly higher than that from database A(p<0.05). Mean intake level of most nutrients from two databases were significantly correlated by Pearson's correlation coefficients(p<0.001). Results from the ranking of nutrient intake levels of the subjects by two databases were highly correlated ( P >0.9, p<0.001). Weighted kappa values representing measures of agreement ranged from 0.55 databases ranged from 45% for vitamin C to 96% for carbohydrate. This result implies that different nutrient database may produce substantial differences in estimating the absolute nutrient intake but may not be crucial in ranking or classifying individuals with regard to specific nutrient intake.

• Korean Journal of Radiology
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• v.22 no.7
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• pp.1034-1043
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• 2021

Objective: The purpose of this meta-analysis was to investigate the pooled agreements of the coronary artery calcium (CAC) severities assessed by electrocardiogram (ECG)-gated and non-ECG-gated CT and evaluate the impact of the scan parameters. Materials and Methods: PubMed, EMBASE, and the Cochrane library were systematically searched. A modified Quality Assessment of Diagnostic Accuracy Studies-2 tool was used to evaluate the quality of the studies. Meta-analytic methods were utilized to determine the pooled weighted bias, limits of agreement (LOA), and the correlation coefficient of the CAC scores or the weighted kappa for the categorization of the CAC severities detected by the two modalities. The heterogeneity among the studies was also assessed. Subgroup analyses were performed based on factors that could affect the measurement of the CAC score and severity: slice thickness, reconstruction kernel, and radiation dose for non-ECG-gated CT. Results: A total of 4000 patients from 16 studies were included. The pooled bias was 62.60, 95% LOA were -36.19 to 161.40, and the pooled correlation coefficient was 0.94 (95% confidence interval [CI] = 0.89-0.97) for the CAC score. The pooled weighted kappa of the CAC severity was 0.85 (95% CI = 0.79-0.91). Heterogeneity was observed in the studies (I² > 50%, p < 0.1). In the subgroup analysis, the agreement between the CAC categorizations was better when the two CT examinations had reconstructions based on the same slice thickness and kernel. Conclusion: The pooled agreement of the CAC severities assessed by the ECG-gated and non-ECG-gated CT was excellent; however, it was significantly affected by scan parameters, such as slice thickness and the reconstruction kernel.

• Journal of Preventive Medicine and Public Health
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• v.30 no.4 s.59
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• pp.852-869
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• 1997

This study was conducted to develop and evaluate the reliability and the validity of a questionnaire in order to determine the applicability as a screening tool for estimating environmental exposure and health effects related to air pollution. The questionnaire was developed with adopting some items of others such as ISAAC or ATS-DLD. And then we performed test-retest to 89 middle school students and their mothers at interval of three months. Cohen's Kappa values, weighted Kappa values, Spearman's correlation coefficients, and Pearson's correlation coefficients for each item were computed as reliability coefficients. The validity coefficients and validity coefficient bounds were also obtained by simply using these reliability coefficients. As results, Kappa ranged broadly from 0.10 to 0.61 of the items 'diet', $0.52\sim0.79$ of the environmental tobacco smoke, $0.39\sim0.44$ of the functional categories of surrounding environment, and $0.39\sim0.44$ of the using transportation systems; these items were regarded as confounding factors. For items related to health outcomes, Kappa ranged from -0.02 to 0.37 in the respiratory system of past medical history, and from 0.11 to 0.55 in the current health status. But Kappa of the others were over 0.60. In conclusion, if some items can be corrected or modified, the questionnaire developed in this study can be used as a tool for evaluating environmental exposure and health effects associated with air pollution.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.1 no.2
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• pp.16-22
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• 1983

The method of least squares is an adequate method of adjustment in various fields of engineering where redundant observations are necessary to obtain accurate values. The Consideration of weight of each Observation can improve the accuracy if the reliabilities of observations vary. The strip coordinates were weighted as inversely proportionate to the rotations $\kappa, \varphi, \omega$ which occur in the computation of model coordinates. The resulting errors in absolute coordinates were compared with the errors unweighted case to investigate the influence of orientation elements on absolute coordinates.

• The korean journal of orthodontics
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• v.40 no.6
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• pp.364-372
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• 2010

Objective: This study was designed to assess the diagnostic validity of digital panoramic radiographs compared to cone beam computed tomography (CBCT) in patients with temporomandibular joint disorders. Methods: Panoramic radiograph and CBCT were taken from a total of 212 joints from 106 subjects. The joints were examined by two dentists and divided into the following six groups: normal, flattening, osteophyte formation, erosion, sclerosis, and unclassified. The sensitivity and specificity of each observer and inter-observer reliability were statistically analyzed. Results: The results showed relatively high intra-observer reliability in the diagnosis of both panoramic and CBCT images and the weighted Kappa indices of panoramic and CBCT images were 0.714 and 0.727, respectively. The sensitivities of panoramic images of observer A and B to CBCT images was 82.35% and 84.30%, respectively, while the specificity of observer A and B was 58.06% and 61.54%, respectively. However, guided diagnosis from panoramic and CBCT images were statistically different (p < 0.05). Conclusions: The present study suggests that the panoramic radiograph could be used as a primary diagnostic device to detect bony changes of temporomandibular joints in clinical orthodontics, because panoramic images showed relatively high sensitivity compared to CBCT images. However, CBCT images may be one of the best choices when a more accurate diagnosis is necessary.

• Physical Therapy Korea
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• v.18 no.3
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• pp.67-75
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• 2011

The purpose of this study was to assess the agreement of manual muscle testing (MMT) and test-retest reliability of a hand held dynamometer for the posterior gluteus medius muscle, with and without lumbar stabilization, using a pressure biofeedback unit for patients with low back pain. The pressure biofeedback unit was used to minimize the substitute motion of the lumbopelvic region during hip abduction in patients lying on their side. Fifteen patients with low back pain participated in this study. A tester determined the MMT grades of the posterior gluteus medius with and without the pressure biofeedback unit. Active hip abduction range of motion with an inclinometer and the strength of their posterior gluteus medius using a hand held dynamometer were measured with and without the pressure biofeedback unit in the MMT position. The agreement of the grade of muscle strength in the MMT, and intra-rater reliability of both the active hip abduction range of motion and the strength of posterior gluteus medius were analyzed using the weighted kappa and intraclass correlation coefficient (ICC), respectively. The agreement of MMT with the pressure biofeedback unit (weighted kappa=.92) was higher than the MMT (weighted kappa=.34)(p<.05). The inclinometer with pressure biofeedback unit measurement of the active hip abduction range of motion had an excellent intra-rater reliability (ICC=.90). Also, the hand held dynamometer with pressure biofeedback unit measure of strength of the posterior gluteus medius had a good intra-rater reliability (ICC=.85). Therefore, the test for muscle strength with pressure biofeedback unit will be a reliable method for the determination of the MMT grades or amount of posterior gluteus medius muscle strength and the measurement of the range of motion for hip abduction in patients with low back pain.

• Journal of Preventive Medicine and Public Health
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• v.31 no.3 s.62
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• pp.361-371
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• 1998

Recent increases of asthma and allergies in childhood made the need for a standardized approach to international and regional comparisons of their prevalence and severity. To address these issues, 'International Study of Asthma and Allergies in Childhood (ISAAC)' is currently underway. In Korea, 'Nationwide Study of Asthma and Allergies in Korean Children' began in 1995 according to ISAAC protocol. ISAAC written and video questionnaires were used in this survey, but their reliability and validity were not evaluated properly yet. In this study, our aim was to evaluate the reliability and validity of two kinds of questionnaires and their usefulness in international and regional comparisons. The test and retest of two questionniares were completed by male(n=110) and female(n=111) middle school students with two and three weeks interval each. Kappa(or weighted kappa) were calculated from each questions and validity coefficients were estimated from those statistics. In Korean version of written questionnaire, the questions for allergic rhinitis, atopic dermatitis, allergic conjunctivitis, and food allergy proved to have high kappa values (or weighted kappa values) and validity coefficients and they can be used in further studies without any correction. But some questions about asthma(especially nocturnal cough, wheezing in exercise, and severe asthma) and drug allergy need to be revised for better under-standing to study subjects. Video questionnaire has the same degree of reliability and validity when compared to written questionnaire and this is the unexpected result. Accordingly, it also need to be revised to overcome the racial and cultural differences of the study subjects. In conclusion, the Korean version of written and video questionnaires may be considered to be useful methods in international and regional comparisons of asthma and allergic diseases in childhood after correction of some questions.