• Proceedings of the Korean Institute of Building Construction Conference
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• 2007.04a
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• pp.33-36
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• 2007

In order to select the optimum mix for the required fluidity and strength of mass concrete which is applied to transfer girder and to choose the optimum curing method depending on circumstances through hydration heat analysis of mass concrete, this study examined slump flow, air content and elapsed variation (0, 30, 60, 90) in unhardened concrete properties and reviewed compressive strength characteristics in hardening properties. And hydration heat analysis results through simulation are as follows; 1) Fluidity changes of unhardened concrete showed no significant difference, and those of elapsed variation also showed no difference but a bit of tendency to increase in comparison with the initial properties. 2) The higher the water-binder ratio was, the lower the compressive strength properties were, and the higher the fly ash replacement rate was, the lower the compressive strength development was. 3) In case of $Fc=40N/mm^2$, the optimum mix was fly ash replacement rate of 15% from water-binder ratio of 33.0%. 4) Hydration heat analysis results showed that in case of bundle cast, concrete temperature profile characteristics around transfer girder was unfavorable, and in case of separate cast, constant curing for at least seven days guaranteed thermal cracking index of 1.2.

• Korea Journal of Hospital Management
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• v.10 no.3
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• pp.67-84
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• 2005

To compare differences of LOS between the group of inpatients via referral centers(the referral group) and the group of inpatients via different routes (the general group) and analyze factors which determine the difference. The 9,484 cases of newly inpatients of Mar., Jun., Sep., Dec. of year 2003 were used for the data. We calculate the Case-mix index of length of stay($CMI_{LOS}$) to compare LOS adjusted with the disease as the ratio of a patient' LOS to all patients' average LOS by 21 classification diagnosis group. We conducted t-test to compare differences of $CMI_{LOS}$ between two groups and multiple regression to analyze factors determining the difference. $CMI_{LOS}$ was 0.94 in the referral group, which was smaller than 1.01 in the general group. LOS was 7.5days in the referral group, which was 0.6day shorter than that in the general group. Multiple regression also showed that $CMI_{LOS}$ was smaller in the referral group than in the general group after controlling patients' general characteristics, diagnostic information variables. The referral centers can be said to playa role in decreasing LOS. We suggest that variety of depth studies on referral centers should be continued at the strategic level of hospital management using additional medical informations.

• Journal of Korean Academy of Nursing Administration
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• v.14 no.3
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• pp.229-240
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• 2008

Purpose: To develop the patient classification system based on the resource utilization for reimbursement of long-term care hospitals in Korea. Method: Health Insurance Review & Assessment Service (HIRA) conducted a survey in July 2006 that included 2,899 patients from 35 long-term care hospitals. To calculate resource utilization, we measured care time of direct care staff (physicians, nursing personnel, physical and occupational therapists, social workers). The survey of patient characteristics included ADL, cognitive and behavioral status, diseases and treatments. Major category criteria was developed by modified delphi method from 9 experts. Each category was divided into 2-3 groups by ADL using tree regression. Relative resource use was expressed as a case mix index (CMI) calculated as a proportion of mean resource use. Result: This patient classification system composed of 6 major categories (ultra high medical care, high medical care, medium medical care, behavioral problem, impaired cognition and reduced physical function) and 11 subgroups by ADL score. The differences of CMI between groups were statistically significant (p<.0001). Homogeneity of groups was examined by total coefficient of variation (CV) of CMI. The range of CV was 29.68-40.77%. Conclusions: This patient classification system is feasible for reimbursement of long-term care hospitals.

• Health Policy and Management
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• v.26 no.2
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• pp.107-114
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• 2016

Background: Over the last few decades, because hospitals in South Korea also have undergone dramatic changes, Korean hospitals traditionally have provided specialized health care services in the health care market. Inner Herfindahl-Hirschman Index (IHI) measures hospital caseloads based on patient proportions, independent of patient volumes. However, IHI that rely solely on patient proportions might be problematic for larger hospitals that provide a high number of diagnosis categories, as the patient proportions in each category are naturally relatively smaller in such hospitals. Therefore, recently developed novel measure, category medical specialization (CMS) is based on patient volumes as well as patient proportions. Methods: We examine the distribution of hospital specialization score by hospital size and investigate association between each hospital specialization and length of stay per case and hospital cost per case using Korean National Health Insurance Service-cohort sample data from 2002 to 2013. Results: Our results show that IHI show a decreasing trend according to the number of beds and hospital type but CMS show an increasing trend according to the number of beds and hospital type. Further, inpatients admitted at hospitals with higher IHI and CMS had a shorter length of stay per case (IHI: B=-0.104, p<0.0001; CMS: B=-0.044, p=0.001) and inpatients admitted at hospitals with higher IHI and CMS had a shorter hospital cost per case (IHI: B=-0.110, p=0.002; CMS: B=-0.118, p=<0.0001). Conclusion: This study may help hospital policymakers and hospital administrators to understand the effects of hospital specialization strategy on hospital performance under recent changes in the Korean health care environment.

• Korea Journal of Hospital Management
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• v.6 no.3
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• pp.148-166
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• 2001

The purpose of this study is to classify elderly patient in long-term care facilities using RUG(Resource Utilization Group)-III. It is designed by measuring patient medical characteristics and medical staff time. Elderly patients are classified into 7 categories by clinical(medical and behavioral) hierarchical typology of patients. Through the tertiary split, all 44 groups are formulated. This classification is explained by each patient resource(staff time) utilization level which is called CMI(Case-Mix Index). Major findings are as follows; 1. The objects in this study were classified into 35 groups out of 44 groups. The most frequent category is clinical complex category(CCC; 38.9%). And extensive service category(ESC; 18.8%), reduced physical function category(RPC; 13.1%), special rehabilitation category(SRC; 12.8%), and impaired cognitive category(ICC; 0.00%) are followed. 2. The mean of total CMI was $1.02{\pm}0.36$, ranging from 0.68 to 1.44(1 vs 2.12). The mean of CMI of SRC is only 1.17 which should be the highest. The means of ESC and see are equally 1.20. The means of CMI of CCI, ICC, BPC, and RPC were 0.90, 0.75, 0.83 and 0.96, respectively. 3. The validity of this classification was tested. Trend-test using Regression Analysis was done in the secondary split level. SCC, CCC, ICC, and RPC which covered 68.4% of this research objects showed linear trend of CMI in interim classification. This results were statistically significant. 4. In clinical hierarchy, the trend were showed linearity. But the multiple comparison of categories using Scheffe-test showed that SRC, ESC and see had same level of CMI means and CCC and ICC, too. This results were statistically significant. Classifying elderly patients with RUG-III, the results showed partly linear trend in clinical hierarchy and in interim classification in conclusion. But, in clinical hierarchy, it was failed to show the consistent order of CMI. It can be explained by two reasons. One is that this research subjects were overlapped in each clinical hierarchy group. And the other is that the some of the characteristics for clinical hierarchy is not appropriate for them. For the further study, it needs to have proper sample size and to modify RUG-III to K-RUG to consider our.. medical environment.

• Journal of Energy Engineering
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• v.23 no.2
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• pp.93-101
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• 2014

How to determine the extent of national energy security? In this paper, we estimate it by comparative analysis of South Korea and other OECD countries in terms of energy diversity (fuel diversity). Energy security consists of 4 key factors such as availability, accessibility, acceptability, affordability. Especially the importance of accessibility can grow as local imbalance of supply and demand increases. As a proxy of the accessibility, fuel diversity can be a significant indicator to estimate a measure of energy security. In this paper, we use Shannon-Wiener index to measure energy diversity. If fuel diversity increases, the stability of energy security also should increase, because of the smoothing effect to lessen dependence on key energy sources. In 2012 Korean growth rate of H-index (energy diversity) is 18.38%, which is higher than other OECD countries. However, Korean H-index itself is 1.93, lesser than other countries. Shift from oil to coals/gas within fossil fuels has more impact on H-index than weight transition from fossil fuels to renewable energies in Korea. We conclude that more renewable energy is an effective solution to achieve higher energy diversity and ultimately higher energy security as the same as the German case.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.7
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• pp.867-874
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• 2014

The pumped storage power plants have excellent load following characteristics. It can also be committed quickly for synchronous reserve when it is in the generating mode because it can readily increase its generating power and, consequently, increases the overall system reliability. There are strong incentives for standing the system reliability. Additionally, $CO_2$ emission can be typically impacted due to operation of pumped generators. The increase or decrease of $CO_2$ depends on the generation mix. This paper proposes evaluation of reliability, economy and environment of power system considering pumped generator. This paper describes three case studies of the reliability and economy and environment according to capacity factor and storage capacity of pumped generators. The probabilistic production simulation model is used in this paper. The practicality and effectiveness of the proposed approach are demonstrated by simulation studies for a real size power system model on the $5^{th}$ power plan in Korea.

• Journal of Korea Port Economic Association
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• v.33 no.3
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• pp.91-104
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• 2017

This paper examines the export structure of Gwangyang Port and evaluates its comparative advantage from 2005 to 2016 using the Comparative Advantage by Countries (CAC) index. It is found that: (i) Gwangyang Port has a comparative advantage in HS 39 and HS 28, an unstable comparative advantage in HS 29 but a comparative disadvantage in HS 72; and (ii) 4 items have the common features of losing their comparative advantage. Constant market share analysis allows one to evaluate why the exports of one region may grow faster than world exports. This consists of the commodity composition effect, the scale effect, and the competitive effect. Constant market share analysis shows that the commodity composition effect influences exports negatively while the scale effect does exports positively. Shift-share analysis can help evaluate the change in a region's performance relative to the nation over a given period of time. The result indicates that HS 28 has not only favorable industrial mix effect but high competitive share effect, while HS 29 has unfavorable industrial mix effect as well as low competitive share effect. This paper also reveals that industrial mix effect of HS 39 is positive but its competitive share effect is negative, whereas the former is negative but the latter is positive in case of HS 29.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.18
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• pp.8093-8100
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• 2016

Background: Genetic and environmental factors play important roles in pathogenesis of digestive tract cancers like those in the esophagus, stomach and colorectum. Folate deficiency and methylenetetrahydrofolate reductase (MTHFR) as an important enzyme of folate and methionine metabolism are considered crucial for DNA synthesis and methylation. MTHFR variants may cause genomic hypomethylation, which may lead to the development of cancer, and MTHFR gene polymorphisms (especially C677T and A1298C) are known to influence predispositions for cancer development. Several case control association studies of MTHFR C677T polymorphisms and colorectal cancer (CRC) have been reported in different populations with contrasting results, possibly reflecting inadequate statistical power. Aim: The present meta-analysis was conducted to investigate the association between the C677T polymorphism and the risk of colorectal cancer. Materials and Methods: A literature search of the PubMed, Google Scholar, Springer link and Elsevier databases was carried out for potential relevant articles. Pooled odds ratio (OR) with corresponding 95 % confidence interval (95 % CI) was calculated to assess the association of MTHFR C677T with the susceptibility to CRC. Cochran's Q statistic and the inconsistency index (I2) were used to check study heterogeneity. Egger's test and funnel plots were applied to assess publication bias. All statistical analyses were conducted by with MetaAnalyst and MIX version 1.7. Results: Thirty four case-control studies involving a total of 9,143 cases and 11,357 controls were retrieved according to the inclusion criteria. Overall, no significant association was found between the MTHFR C677T polymorphism and colorectal cancer in Asian populations (for T vs. C: OR=1.03; 95% CI= 0.92-1.5; p= 0.64; for TT vs CC: OR=0.88; 95%CI= 0.74-1.04; p= 0.04; for CT vs. CC: OR = 1.02; 95%CI= 0.93-1.12; p=0.59; for TT+ CT vs. CC: OR=1.07; 95%CI= 0.94-1.22; p=0.87). Conclusions: Evidence from the current meta-analysis indicated that the C677T polymorphism is not associated with CRC risk in Asian populations. Further investigations are needed to offer better insight into any role of this polymorphism in colorectal carcinogenesis.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.75-75
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• 2022

Traditional agriculture mostly focused on activity in the field, but current agriculture faces problems such as reduction of agricultural inputs, labor shortage and so on. Accordingly, traditional agricultural experiments generally considered the simple treatment effects, but current agricultural experiments need to consider the several and complicate treatment effects. To analyze such several and complicate treatment effects, data collection has the first priority. Remote sensing is a quite effective tool to collect information in agriculture, and recent easier availability of UAVs (Unmanned Aerial Vehicles) enhances the effectiveness. LAI (Leaf Area Index) is one of the most important information for evaluating the condition of crop growth. In this study, we utilized UAV with multispectral camera to evaluate plant-based LAI of sweetcorn in a small-scale field experiment and discussed the feasibility of a new experimental design to analyze the several and complicate treatment effects. The plant-based SR measured by UAV showed the highest correlation coefficient with LAI measured by a canopy analyzer in 2018 and 2019. Application of linear mix model showed that plant-based SR data had higher detection power due to its huge number of data although SR was inferior to evaluate LAI than the canopy analyzer. The distribution of plant-based data also statistically revealed the border effect in treatment plots in the traditional experimental design. These results suggest that remote sensing with UAVs has the advantage even in a small-scale experimental plot and has a possibility to provide a new experimental design if combined with various analytical applications such as plant size, shape, and color.