• The Korean Journal of Applied Statistics
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• v.29 no.1
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• pp.41-59
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• 2016

There have been continuous improvements in human life expectancy. Life expectancy is as a key factor in an aging population and can wreak severe damage on the financial integrity of pension providers. Hence, the projection of the accurate future mortality is a critical point to prevent possible losses to pension providers. However, improvements in future mortality would be overestimated by a typical mortality projection method using the Lee-Carter model since it underestimates the mortality index ${\kappa}_t$. This paper suggests a mortality projection based on the projection of the skewness of the mortality versus the typical mortality projection of the Lee-Carter model based on the projection of the mortality index, ${\kappa}_t$. The paper shows how to indirectly estimate future t trend with the skewness of the mortality and compares the results under each estimation method of the mortality index, ${\kappa}_t$. The analysis of the results shows that mortality projection based on the skewness presents less improved mortality at an elderly ages than the original projection.

• Journal of the Korean Association of Geographic Information Studies
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• v.23 no.2
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• pp.21-35
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• 2020

Vegetation information is a very important factor used in various fields such as urban planning, landscaping, water resources, and the environment. Vegetation varies according to canopy density or chlorophyll content, but vegetation vitality is not considered when classifying vegetation areas in previous studies. In this study, in order to satisfy various applied studies, a study was conducted to set a threshold value of vegetation index considering vegetation vitality. First, an eBee fixed-wing drone was equipped with a multi-spectral camera to construct optical and near-infrared orthomosaic images. Then, GIS calculation was performed for each orthomosaic image to calculate the NDVI, GNDVI, SAVI, and MSAVI vegetation index. In addition, the vegetation position of the target site was investigated through VRS survey, and the accuracy of each vegetation index was evaluated using vegetation vitality. As a result, the scenario in which the vegetation vitality point was selected as the vegetation area was higher in the classification accuracy of the vegetation index than the scenario in which the vegetation vitality point was slightly insufficient. In addition, the Kappa coefficient for each vegetation index calculated by overlapping with each site survey point was used to select the best threshold value of vegetation index for classifying vegetation by scenario. Therefore, the evaluation of vegetation index accuracy considering the vegetation vitality suggested in this study is expected to provide useful information for decision-making support in various business fields such as city planning in the future.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.32 no.3
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• pp.57-64
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• 2000

This study was carried out to acquire basic data necessary for the use of non-wood pulp. It investigated various chemical pulping methods using bamboo to achieve higher yield lower kappa no. and then the physical properties of various pulps were tested. The results of this study were as follows. When various chemical pulps(Soda, Soda-AQ, Soda-AQ-H2O2, Soda-urea, AS, AS-AQ, Kraft) were produced with bamboo. the pulps with the higher yield and lower kappa no. were AS-AQ and Kraft. In the case of the breaking length Soda pulps(5.77∼6.46 km) showed the greatest and Soda-urea pulps(3.81∼4.522km) showed the lower value. Similarly for the burst index Soda pulps (3.28∼3.50 kPa$.$m2/g) were the best and Soda-urea pulps(2.29∼2.39 kPa$.$m2/g) were worst. On the other hand the tearing indexes of AS-AQ pulps(73.6∼89.7mN$.$m2/g) showed the tendency which was higher then those of other pulps.

• The Journal of Engineering Geology
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• v.31 no.3
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• pp.395-432
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• 2021

Groundwater recharge rates vary widely by location and with time. They are difficult to measure directly and are thus often estimated using simulations. This study employed frequency and regression analysis and a classification and regression tree (CART) algorithm in a machine learning method to estimate groundwater recharge. CART algorithms are considered for the distribution of precipitation by subbasin (PCP), geomorphological data, indices of the relationship between vegetation and landuse, and soil type. The considered geomorphological data were digital elevaion model (DEM), surface slope (SLOP), surface aspect (ASPT), and indices were the perpendicular vegetation index (PVI), normalized difference vegetation index (NDVI), normalized difference tillage index (NDTI), normalized difference residue index (NDRI). The spatio-temperal distribution of groundwater recharge in the SWAT-MOD-FLOW program, was classified as group 4, run in R, sampled for random and a model trained its groundwater recharge was predicted by CART condidering modified PVI, NDVI, NDTI, NDRI, PCP, and geomorphological data. To assess inter-rater reliability for group 4 groundwater recharge, the Kappa coefficient and overall accuracy and confusion matrix using K-fold cross-validation were calculated. The model obtained a Kappa coefficient of 0.3-0.6 and an overall accuracy of 0.5-0.7, indicating that the proposed model for estimating groundwater recharge with respect to soil type and vegetation cover is quite reliable.

• Korean Journal of Food Science and Technology
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• v.32 no.3
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• pp.604-609
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• 2000

This study was carried out to investigate the possibilities of adopting xanthangum, guargum and ${\kappa}-carrageenan$ as cryprotectant by examining the rheological and structural properties of dough. Results of farinography showed that water absorption, development time and mechanical tolerance index in dough with the gums increased more than those of the control. It was also found that resistance in dough with the gums increased greatly, but extensibilities were similar to that of the control, resulting in increasing R/E values in the dough with the gums through extensograph. According to amylogram, gelatinization temperature of dough was $59.5^{circ}C$ and those of the dough with the gums were $58^{circ}C$. Even though maximum viscosity of the dough was 550 B.U in the control, those were 690 B.U, 780 B.U and 760 B.U in the dough with xanthangum, guargum, and ${\kappa}-carrageenan$, respectively. The control deeply increased the pH during frozen storage but the addition of ${\kappa}-carrageenan$ and xanthangum increased the pH slightly. The dough with the gums had more stable spaces than control in the microstructure through SEM.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.26 no.2
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• pp.10-18
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• 2013

Objectives : We performed a pilot study to investigate inter- and intra-rater reliability of pattern identification using nasal endoscopy for allergic rhinitis(AR). Methods : Eight experts of ophthalmology, otolaryngology and dermatology of Korean medicine evaluated 20 nasal endoscopy photograph cases of AR patients with pattern identification index using nasal endoscopy for AR including the nasal membrane color(pale / hyperemia), nasal membrane humidity(dryness / dampness), rhinorrhea(watery / yellow), and membrane edema (atrophic / edematous) on nasal endoscopy. Results : Intra-rater agreement(%) and Kappa coefficient was generally from 'moderate' to 'good'(% agreement: 73.13-90% / Kappa coefficient: 0.547-0.748). Inter-rater agreement(%) and Kappa coefficient was also from 'moderate' to 'good' (% agreement: 65-85% / Kappa: 0.475-0.778) except 'humidity(dryness / dampness)' item (% agreement: 55.98% / Kappa: 0.340). In findings of subgroup analysis according to affiliation of raters, Inter-rater agreement(%) and Kappa coefficient of raters in same affiliation was higher than inter-rater agreement(%) and Kappa coefficient of raters in different affiliation except 'dryness / dampness' item. Conclusions : It is necessary to improve objectivity and reproducibility of pattern identification using nasal endoscopy for allergic rhinitis(AR) through the development of detail-oriented criteria and enhanced training of clinicians with development of standard operating procedures(SOPs).

• Journal of Preventive Medicine and Public Health
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• v.43 no.5
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• pp.396-402
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• 2010

Objectives: Self-reported anthropometric values, such as height and weight, are used to calculate body mass index (BMI) and assess the prevalence of obesity among adolescents. The aim of this study was to evaluate the validity of selfreported height, weight, and BMI of the Korea Youth Risk Behavior Web-based Survey questionnaire. Methods: A convenience sample of 137 middle school students and 242 high school students completed a selfadministered questionnaire in 2008. Body height and weight were directly measured after self-reported values were obtained from the questionnaire survey. Sensitivity, specificity, and kappa statistics were computed in order to evaluate the validity of the prevalence of obesity (BMI $\geq$ 95th percentile or $\geq$ $25;kg/$m^2$) based on self-reported data. Results: Self-reported weight and BMI tended to be underestimated. Self-reported height tended to be overestimated among middle school females and high school males. Obese adolescents tended to underestimate their weight and BMI and overestimate their height more than non-obese adolescents. The prevalence estimate of obesity based on selfreported data (10.6%) was lower than that based on directly measured data (15.3%). The estimated sensitivity of obesity based on self-reported data was 69.0% and the specificity was 100.0%. The value of kappa was 0.79 (95% confidence interval, 0.70 - 0.88). Conclusions: This study demonstrated that self-reported height and weight may lead to the underestimation of BMI and consequently the prevalence of obesity. These biases should be taken into account when self-reported data are used for monitoring the prevalence and trends of obesity among adolescents nationwide.

• Journal of Preventive Medicine and Public Health
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• v.55 no.3
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• pp.234-242
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• 2022

Objectives: This study assessed the validity and reliability of the Health-related Quality of Life Instrument with 8 Items (HINT-8) in patients with diabetes. HINT-8 is a newly-developed, generic health-related quality of life (HRQoL) instrument. Methods: Three HRQoL instruments-HINT-8, EuroQoL 5-Dimension 5-Level (EQ-5D-5L), and Short Form Health Survey version 2.0 (SF-36v2)-were provided to 300 patients with diabetes visiting a tertiary hospital for follow-up visits in Korea. The HRQoL scores obtained using the HINT-8 were evaluated for subgroups with known differences based on demographics and diabetes-related characteristics (known-group validity). The mean scores of the instruments were compared between groups segmented by their responses to the HINT-8 (discriminatory ability). Correlation coefficients of the HINT-8 with other instruments were calculated (convergent and divergent validity). The Cohen kappa and intra-class correlation coefficient (ICC) were also evaluated (test-retest reliability). Results: The average HINT-8 indexes were lower among women, older, and less-educated subjects. Subjects who did not list any problems on the HINT-8 had significantly higher HRQoL scores than those who did. The correlation coefficients of the HINT-8 with the EQ-5D-5L index and EuroQoL visual analogue scale were 0.715 (p<0.001) and 0.517 (p<0.001), respectively. The correlation coefficients between the HINT-8 index and the scores of 8 domains of the SF-36v2 ranged from 0.478 (p<0.001) to 0.669 (p<0.001). The Cohen kappa values for the HINT-8 ranged from 0.268 to 0.601, and the ICC of the HINT-8 index was 0.800 (95% confidence interval [CI], 0.720 to 0.860). Conclusions: This study showed that the HINT-8 is a valid and reliable HRQoL instrument for patients with diabetes.

• Korean Journal of Remote Sensing
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• v.26 no.6
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• pp.665-673
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• 2010

The role of remote sensing in phenological studies is increasingly regarded as a key in understanding large area seasonal phenomena. This paper describes the application of Moderate Resolution Imaging Spectroradiometer (MODIS) time series data for vegetation classification using seasonal variation patterns. The vegetation seasonal variation phase of Seoul and provinces in Korea was inferred using 8 day composite MODIS NDVI (Normalized Difference Vegetation Index) dataset of 2006. The seasonal vegetation classification approach is performed with reclassification of 4 categories as urban, crop land, broad-leaf and needle-leaf forest area. The BISE (Best Index Slope Extraction) filtering algorithm was applied for a smoothing processing of MODIS NDVI time series data and fuzzy classification method was used for vegetation classification. The overall accuracy of classification was 77.5% and the kappa coefficient was 0.61%, thus suggesting overall high classification accuracy.

• Journal of Preventive Medicine and Public Health
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• v.38 no.4
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• pp.443-448
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• 2005

Objectives : This study was done to evaluate the reliability of education and occupational class between using the health survey and the death certificate data. Methods : The 1998 National Health and Nutrition Examination Survey (NHANES) was conducted on a cross-sectional probability sample of South Korean households, and it contained unique 13-digit personal identification numbers that were linked to the data on mortality from the Korean National Statistical Office. The data from 263 deaths were used to estimate the agreement rates and the Kappa indices of the education and occupational class between using the NHANES data and the death certificate data. Results : The simple and weighted Kappa indices for education were 0.60 (95% CI=0.53-0.68) and 0.73 (95% CI=0.67-0.79) respectively, if the educational level was grouped into five categories: no-formal-education, elementary-school, middle-school, high-school and college or over. The overall agreement rate was 71.9% for these educational groups. The magnitude of reliability, as measured by the overall agreement rates and Kappa indices, tended to increase with a decrease in the educational class. The number of non-educated people with using the death certificate data was smaller than that with using the NHANES data. For the occupational class (manual workers, non-manual workers and others), the Kappa index was 0.40 (95% CI=0.30-0.51), which was relatively lower than that for the educational class. Compared with the NHANES, the number of non-manual workers for the deceased who were aged 30-64 tended to be increased (8 to 12) when using the death certificate data, whereas the number of manual workers tended to be decreased (59 to 41). Conclusions : The socioeconomic inequalities in the mortality rates that were based on the previous unlinked studies in South Korea were not due to a numerator/denominator bias. The mortality rates for the manual workers and the no-education groups might have been underestimated.