• Proceedings of the Safety Management and Science Conference
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• 2005.05a
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• pp.503-521
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• 2005

Process capability indices are widely used in industries and quality assurance system. When designing the parameter on the multiple quality characteristics, there has been a study for optimization of problems, but there has been few former study on the possible conflicting phenomena in considertion of the correlations among the characteristics. To solve the issue on the optimal design for muliple quality characteristics, the study propose the expected loss function with cross-product terms among the characteristics and derived range of the coefficients of terms. Therefore, the analysis have to be required a multivariate statistical technique. This paper introduces to multivariate capability indices and then selects a multivariate process capability index incorporated both the process variation and the process deviation from target among these indices under the multivariate normal distribution. We propose a new multivariate capability index $MC_{pm}^{++}$ using quality loss function instead of the process variation and this index is compared with the proposed indices when quality characteristics are independent and dependent of each other,

• Proceedings of the Safety Management and Science Conference
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• 2004.11a
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• pp.69-79
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• 2004

Process capability indices are widely used in industries and quality assurance system. When designing the parameter on the multiple quality characteristics, there has been a study for optimization of problems, but there has been few former study on the possible conflicting phenomena in considertion of the correlations among the characteristics. To solve the issue on the optimal design for multiple quality characteristics, the study propose the expected loss function with cross-product terms among the characteristics and derived range of the coefficients of terms. Therefore, the analysis have to be required a multivariate statistical technique. This paper introduces to multivariate capability indices and then selects a multivariate process capability index incorporated both the process variation and the process deviation from target among these indices under the multivariate normal distribution. We propose a new multivariate capability index $MC_{pm}^{++}$ using quality loss function instead of the process variation and this index is compared with the proposed indices when quality characteristics are independent and dependent of each other.

• Journal of Trauma and Injury
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• v.28 no.3
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• pp.115-122
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• 2015

Purpose: To calculate Preventable Trauma Death Rate (PTDR), Trauma and Injury Severity Score (TRISS) is the most utilized evaluation index of the trauma centers in South Korea. However, this method may have greater variation due to the small number of the denominator in each trauma center. Therefore, we would like to develop new indicators that can be used easily on quality improvement activities by increasing the denominator. Methods: The medical records of 1005 major trauma (ISS >15) patients who visited 2 regional trauma center (A center and B center) in 2014 were analyzed retrospectively. PTDR and PARK Index (Preventable Major Trauma Death Rate, PMTDR) were calculated in 731 patients with inclusion criteria. We invented PARK Index to minimize the variation of preventability of trauma death. In PTDR the denominator is all number of deaths, and in PARK Index the denominator is number of all patients who have survival probability (Ps) larger than 0.25. Numerator is the number of deaths from patients who have Ps larger than 0.25. Results: The size of denominator was 40 in A center, 49 in B center, and overall 89 in PTDR. The size of denominator was significantly increased, and 287 (7.2-fold) in A center, 422 (8.6-fold) in B center, and overall 709 (8.0-fold) in PARK Index. PARK Index was 12.9% in A center, 8.3% in B center, and overall 10.2%. Conclusion: PARK Index is calculated as a rate of mortality from all major trauma patients who have Ps larger than 0.25. PARK Index obtain an effect that denominator is increased 8.0-fold than PTDR. Therefore PARK Index is able to compensate for greater disadvantage of PTDR. PARK Index is expected to be helpful in implementing evaluation of mortality outcome and to be a new index that can be applied to a trauma center quality improvement activity.

• Journal of The Korean Society of Agricultural Engineers
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• v.54 no.4
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• pp.115-125
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• 2012

The comparison between the spatial and temporal variability of aridity index, precipitation effectiveness and runoff during El-Nino and La-Nina periods and that of the normal period was conducted to evaluate the regional impacts of El-Nino, La-Nina in hydrologic variables. Aridity index and precipitation effectiveness were estimated using 59 nationwide weather stations data and runoff data of WAMIS were used. The ratio of the difference between El-Nino, La-Nina year value and that of normal year was analyzed. Temporal variation demonstrated that aridity index, precipitation effectiveness and run-off discharge increase in March, April, August, November, December and decrease in February, June, September, October according to El-Nino effect. Aridity index, precipitation effectiveness and run-off discharge increase in March, May, September and decrease in June, August, November, December according to La-Nina effect. The spatial variation of those variables analyzed for different basins showed that impacts in the Han river basin relatively higher than that of other basins.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.146-146
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• 2019

The aridity index, which is determined as the ratio of potential evapotranspiration to precipitation, is one of key parameters in drought characterization. Whereas the evaporative index, which is defined as the ratio of actual evapotranspiration to precipitation, represents the fraction of available water consumed by the evapotranspiration process. This study investigates variation of the aridity and evaporative indexes due to climate change during the 21st century in South Korea. Estimations of the aridity and evaporative indexes are obtained using SWAT mode based on ensemble of 13 different GCMs over 5 large basins of South Korea for 2 RCP scenarios (RCP 4.5 and RCP 8.5). The results shows the opposite trends of the two indexes, where the aridity index is projected as always increase, while the evaporative index is expected to decrease in all of 3 future period (2011-1940, 1941-1970, 1971-2099). The estimated results also suggest that land cover influenced significantly evapotranspiration along with the change of climate. The study indicates that South Korea will be facing with a high risk of water scarcity in future due to climate change, which is seriously challenging for water planing and management in the country.

• Journal of the Korean GEO-environmental Society
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• v.13 no.11
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• pp.43-50
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• 2012

In this research, the value of consolidation index was investigated. The range of the investigated standard deviation was analyzed and the deviation based settlement was calculated. Also, the compression index, which is the effect of the uncertainty in the ground was analyzed using the flimsy ground construction method. The settlement behavior in each embankment compaction stage was analyzed by applying the precompression load method, drainage expediting method, and displacement method through numerical analysis. In addition to the above, the settlement behavior was studied by analyzing the Piled Raft method which is stable for long term settlement. As a result, the final settlement amount based on average analysis results was that the settlement based on each of the average interpretation value, mean value of the maximum and minimum value and average compression index was different. The result of the comparison shows the difference in variation coefficient by the difference in time. Amongst them, the Piled Raft method shows the most consistent variation coefficient regardless of time and it also was least affected by the compression index of uncertainty.

• The Journal of the Korea Contents Association
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• v.17 no.1
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• pp.201-212
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• 2017

This study presented the new evaluation index which can evaluate the discrimination of DEA models. To evaluate the discrimination of DEA models, data were analyzed using importance index as suggested in previous study and the coefficient of variation as suggested in this study for the discrimination evaluation. This study selected the CCR-DEA, BCC-DEA, entropy, bootstrap, super efficiency, and cross efficiency DEA model for the discrimination evaluation and accomplished empirical analysis. In order to grasp the rank correlation of the models, this study implemented the rank correlation analysis between the efficiency of CCR model and BCC model and entropy, bootstrap, super efficiency, and efficiency of the cross efficiency model. The obtained results of this study are as follows. First, the discrimination rank of models using the importance index and the coefficient of variation was shown to be identical. Therefore, the coefficient of variation can be used the discrimination evaluation index of DEA model. Second, the discrimination of the super efficiency model was found to be the highest rank among 4 models according to the analysis of this present study. Third, the highest rank correlation with CCR model was the super efficiency model. In addition, the super efficiency model was found to be the highest rank correlation with BCC model.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.60 no.2
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• pp.114-127
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• 2024

A variation of fish assemblage in the coastal waters of Sagye-ri, southern Jeju Island was determined using samples collected by trammel net from 2012 to 2022. The total fish species caught by trammel net were identified 88 species, 46 families, 12 orders, and the number of appearance and biomass were 3,479 individuals and 883.6 kg. The annual variation of species was the highest in 2013 at 46 species and the lowest in 2021 at 30 species. The seasonal variation of species was higher in summer at 67 species and lower in winter, autumn at 47 species. The annual diversity index, evenness index, and richness index were appeared 2.42-3.00, 0.69-0.78 and 5.18-7.24 at each years. The dominance index appeared highest in 2013 and the lowest in 2018. Cluster analysis based on the number of individuals of fish was classified into two groups at the dissimilarity level of 57%, and results of SIMPROF analysis revealed significant differences in community structure among the two groups. The subtropical fishes were identified a total of 42 species (47.7%) and the number of species was higher in 2013 at 25 (54.3%) species and lower in 2018 and 2021 at each 17 (54.8~56.7%) species. The dominant species of subtropical fishes were appeared rabbit fish (Siganus fuscescens), scarbreast tuskfish (Choerodon azurio), bluestriped angelfish (Chaetodontoplus septentrionalis), balloon fish (Diodon holocanthus), and flag fish (Goniistius zonatus) at study sites.

• Korean Journal of Agricultural and Forest Meteorology
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• v.5 no.3
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• pp.200-207
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• 2003

'||'||'||'&'||'||'||'quot;Overheating index'||'||'||'&'||'||'||'quot;, the normalized difference in incident solar energy between a target surface and a level surface, is helpful in estimating the spatial variation in daily maximum temperature at the landscape scale. It can be computed as the ratio of the 4-hour cumulative solar irradiance surplus or deficit from that over a level surface to the maximum possible deviation (15 MJ $m^{-2}$ ) during the midafternoon. Ecosystem models may, for simplicity, use an empirical proxy (exposure index) variable combining slope and aspect in place of the overheating index to account for the variation of midafternoon solar irradiance. A comparative study with real-world landscape data was carried out to evaluate the performance of exposure index in replacing the overheating index. Overheating indices for summer solstice, fall equinox and winter solstice were calculated at 573,650 grid cells constituting the land surface of Donggye-Myun, Sunchang County in Korea, based on a 10-m DEM. Exposure index was also calculated for the same area and fitted for the variation of overheating index to derive a 2$^{nd}$ -order linear regression equation. The coefficient of determination ($R^2$) was 0.50 on summer solstice, 0.56 on fall equinox, and 0.44 on winter solstice, respectively. These are much lower than the theoretically calculated $R^2$ values ranging from 0.7 in summer to 0.9 in autumn. According to our study, exposure index failed to accurately predict the cumulative solar irradiance over a complex terrain, hindering its application to daily maximum temperature estimation. We suggest direct calculation of the overheating index in preference to using the exposure index.

• Journal of the Korean Association of Geographic Information Studies
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• v.11 no.2
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• pp.28-37
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• 2008

In this study, we perform land surface monitoring of NDVI (Normalized Difference Vegetation Index) variation by using remote sensing data during 1999-2005 over North Korea, which can't easily access to measure directly land surface characteristics due to one of the world's most closed societies. North Korea forest region has most abundant forest vegetation - so called Lungs of Korea in the Korea peninsula. NDVI represents vegetation activity used in many similar studies. In this study, we detect vegetation variation and analysis factors of the change over North Korea. By using variation of NDVI, we can infer that effect of drought over North Korea, and reduced vegetation indices by typhoon in North Korea. Land surface type except barren ground with decreased NDVI value is considered as when North Korea region was suffering from drought and typhoon effects, which show lower than mean of 7-year NDVI value. Especially, in recently, the food production of North Korea with political and economical issues can be inferred indirectly these trends by using estimated output data from this study.