• Journal of Korean Society of Industrial and Systems Engineering
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• v.19 no.37
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• pp.111-115
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• 1996

This study is to decide each level ordering policy for deterministic demand in multilevel distribution system. The ordering policy is used the combinations of EOQ and LTC. The combinations of EOQ and LTC are 4 cases. Case 1 : Regional Warehouse∼EOQ, Central Warehouse∼EOQ. Case 2 : Regional Warehouse∼EOQ, Central Warehouse∼LTC. Case 3 : Regional Warehouse∼LTC, Central Warehouse∼EOQ. Case4 : Regional Warehouse∼LTC, Central Warehouse∼LTC. The criterion is to minimize total cost per year.

• KIEE International Transactions on Power Engineering
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• v.4A no.4
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• pp.207-213
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• 2004

In this paper, the on-line volt/var control algorithms of the Load Tap Changer (LTC) transformer and Shunt Capacitor (SC) are proposed for distribution volt/var compensation. In the existing volt/var control of the distribution substation, the feeder voltage and reactive power demand of the distribution are mainly controlled by the LTC transformer tap position and on/off operation of the Sc. It is very difficult to maintain volt/var at the distribution networks within the satisfactory levels due to the discrete operation characteristics of the LTC and SC. In addition, there is the limitation of the LTC and SC operation times, which affects their functional lifetimes. The proposed volt/var control algorithm determines an optimal tap position of the LTC and on/off status of the SC at a distribution substation with multiple connected feeders. The mathematical equations of the proposed method are introduced. A simple case study is performed to verify the effectiveness of the proposed method.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05a
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• pp.413-418
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• 1996

The main purpose of this paper is to develop the modified LTC code for accurate analysis of the boron concentration behavior of all components in the Nuclear Steam Supply System (NSSS). This is achieved by adapting a multi-cell mad to the existing Long Term Cooling (LTC) code. To verify the modified LTC, the simulated results were compared with the actual test results measured during YGN 4 initial criticality test. It was shown that the simulated results of this modified LTC were in good agreement with the actual test results. Also, the boron concentration behavior analysis were performed using the modified LTC code for both direct and indirect dilution/boration nude using YGN 3,4 design data. This modified LTC code can provide a valuable information in predicting boron concentration behavior during power maneuvering such as startup operation, shutdown operation and load follow operation. It is expected that the modified LTC can be applied to both on-line and off-line mode using Plant Computer System(PCS).

• Health Policy and Management
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• v.26 no.4
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• pp.305-314
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• 2016

Background: The purpose of this study is to examine the characteristics of and factors associated with long-term care (LTC) utilization under public long-term care insurance (LTCI) among end-of-life older adults in Korea. Methods: Using a 5% sample of older people aged 65 or older and their health and LTC insurance data, two-part model analyses were conducted. We compared LTC uses and their determinants during the last year of life among decedents in the year 2010 with those of survivors. We also compared the medical uses of the same sample with their LTC uses. Results: The end-of-life elderly were more likely to use LTC, and their expenditure on LTC was higher than their counterparts. Whether or not older people used LTC during their last year of life was significantly affected by age, sex, health insurance, household income, and living alone; however, LTC costs of the decedents were only affected by functional status, which may have been due to the reimbursement scheme of the current LTCI, which is mainly based on functional dependency level. For the survivors, having chronic diseases significantly increased the likelihood of LTC use, which was not the case for the decedents. End-of-life elderly with relatively low social economic status were more likely to use the LTC other than medical services, while the health conditions affected their medical uses most significantly. Conclusion: The study findings provide key information for predicting demand related to the increasing LTC needs of Korean older people at the end of life.

• Health Policy and Management
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• v.32 no.4
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• pp.389-399
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• 2022

Background: This study aimed to analyze changes in medical utilization and cost before and after long-term care (LTC) implementation. Methods: We used the National Health Information Database from National Health Insurance Service. The participants were selected who had a new LTC grade (grade 1-5) for 2015. Medical utilization was analyzed before and after LTC implementation. Segmented regression analysis of interrupted time series was conducted to evaluate the overall effect of the LTC implementation on medical costs. Results: The total number of participants was 41,726. A major reason for hospitalization in grade 1 was cerebrovascular diseases, and dementia was the top priority in grade 5. The proportion of hospitalization in grade 1 increased sharply before LTC implementation and then decreased. In grade 5, it increased before LTC implementation, but there was no significant difference after LTC implementation. As for medical cost, in grades 1 to 4, the total cost increased sharply before the LTC implementation, but thereafter, changes in level and trend tended to decrease statistically, and for grade 5, immediately after LTC implementation, the level change was decreasing, but thereafter, the trend change was increasing. Conclusion: Long-term care grades showed different medical utilization and cost changes. Long-term care beneficiaries would improve their quality of life by adequately resolving their medical needs by their grades.

• Research in Community and Public Health Nursing
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• v.27 no.4
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• pp.388-398
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• 2016

Purpose: To compare the changes in activities of daily living (ADLs) in older adults with stroke in different modalities of long term care (LTC) services, which include home care and institutional care. Methods: This is a comparative study using secondary data from the Korean national LTC insurance. Home care (HC) services users (n=3,494) and institutional care (IC) users (n=1,428) were extracted and compared in terms of ADLs and changes in ADLs to investigate the effects of HC and IC services in LTC. Results: All of the ADLs and LTC services benefit levels for 2 years had improved in both HC and IC services. The ADLs of older adults with stroke who received HC improved, while those who received IC experienced deterioration. The LTC services benefit levels of the HC and IC groups were significantly different after 2 years. Conclusion: The study has found that HC services may lead ADLs better for older adults with stroke. We recommend LTC policy makers to further develop HC and IC service programs to deliver quality LTC services.

• Clinical and Experimental Pediatrics
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• v.48 no.7
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• pp.766-771
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• 2005

Purpose : Cysteinyl leukotrienes are important inflammatory mediators in the pathogenesis of asthma; therefore interruption of cysteinyl leukotrienes by leukotriene receptor antagonists improves clinical symptoms in the management of patients with mild to moderate asthma. We evaluated whether clinical response to montelukast, a leukotriene receptor antagonist, in childhood asthma was predicted by genotypes of leukotriene $C_4$ synthase($LTC_4S$) promoter gene polymorphism. Methods : An 8-week prospective, open trial of montelukast was carried out in 161 children with mild to moderate asthma. Genotyping of $LTC_4S$ gene polymorphism was determined by restriction fragment length polymorphism. Results : The distribution of the $LTC_4S$ genotypes AA, AC, and CC was 70.8 percent, 23.6 percent, and 5.6 percent, respectively in asthma group and 74.0 percent, 22.6 percent, and 3.4 percent, respectively in control group. A statistically significant difference in the distribution of $LTC_4S$ genotype was not observed between the asthma and the control groups, and there was no significant difference between the $LTC_4S$ genotype and asthma severity. The responders to montelukast were significantly prevalent in the mild asthma group(P<0.05). There was no significant difference in the distribution of the responders compared to non-responders within genotype in the total asthma group or the moderate asthma group. However, the responsiveness for montelukast was significant difference within genotype for both AA and AC/CC in the mild asthma group : The AA genotype was more included in the responder group(P<0.05). Conclusion : In the mild persistent asthma group, the A allele of $LTC_4S$ polymorphism may be regarded as a predictable factor for clinical response to montelukast. However, LTC4S polymorphism was not significantly associated with the clinical response to montelukast in asthmatic children.

• Clinical and Experimental Pediatrics
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• v.52 no.6
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• pp.680-688
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• 2009

Purpose : Cysteinyl leukotrienes are important proinflammatory mediators in asthma. Recently, it was suggested that a promoter polymorphism in the genes encoding for leukotriene C4 synthase (LTC4S), a key enzyme in the leukotriene synthetic pathway, and cysteinyl leukotriene receptor 1 (CysLTR1) might be associated with aspirin-intolerant asthma. We investigated whether polymorphisms in LTC4S and CysLTR1 genes or their interactions were associated with the asthma phenotype, lung function, or bronchial hyperreactivity (BHR) in Korean children. Methods : A total of 856 asthmatic children and 254 non-asthmatic controls were enrolled; a skin prick test, lung function test and bronchial provocation test were performed. Of those enrolled, 395 children underwent exercise challenge tests. The LTC4S A(-444)C and CysLTR1 T(＋927)C were genotyped by polymerase chain reaction-restriction fragment length polymorphism analysis. Results : Of those enrolled, 699 children were classified as having atopic asthma and 277 children, as having exercise-induced asthma (EIA). LTC4S and CysLTR1 polymorphisms were not associated with atopic asthma, EIA, or asthma per se. Lung function and BHR were not significantly different between the wild type (AA or TT) and the variant (AC＋CC or TC＋CC) genotypes in asthmatics, atopic asthmatics, and EIA (＋) asthmatics, while total eosinophil counts were higher in the variant type of LTC4S than in the wild type in atopic asthmatics. There were no associations between the gene-gene interactions of LTC4S and CysLTR1 genotypes and the asthma phenotypes. Conclusion : LTC4S A(-444)C and CysLTR1 T(＋927)C polymorphisms and their gene-gene interactions are not associated with asthma phenotype, lung function, or BHR in Korean children.

• Restorative Dentistry and Endodontics
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• v.21 no.2
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• pp.451-469
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• 1996

The purpose of this study was to investigate the effect of calcium hydroxide and glass ionomer cement fillings on the levels of $LTB_4$ and $LTC_4$ in experimentally inflamed rat dental pulp. The dental pulp in the mandibular incisor of wistar rat was irritated by cutting a 5mm deep hole in the dentin with a twist drill bur of 0.5mm diameter, without cooling. The cavities were filled with calcium hydroxide(light-cured) and glass ionomer cement(light cured). The untreated pulp served as control tissue specimen. After cavity preparations, the rat with or without various treatment were sacrificed in various time by decapitation. The dental pulp tissue were carefully removed and the concentrations of $LTB_4$ and $LTC_4$ were determined by radioimmunoassay. And pulps were examined histologically to observe inflammatory feature. The result were obtained as follows : 1. The inflammatory features of pulps were observed microscopically in all experimental groups. And degree of inflammation was decreased with time. 2. The concentrations of $LTB_4$ and $LTC_4$ for all experimental groups were significantly higher than those for control group 6 hours after cavity preparation(p<0.05). 3. The group filled with calcium hydroxide was the lowest, and the group filled with glass ionomer cement, the group of irritation in that order showed increased concentrations of $LTB_4$ and $LTC_4$ 6 hours after cavity preparation. In the concentrations of $LTB_4$, significant differences among 3 groups were noted(p<0.05). 4. The group filled with calcium hydroxide was the lowest, and the group filled with glass ionomer cement, the group of irritation in that order showed increased concentrations of $LTB_4$ and $LTC_4$ 24 hours after cavity preparation. And there were statistically significant difference in concentrations of $LTB_4$ between the group of irritation and the group filled with calcium hydroxide(p<0.05). 5. The group filled with calcium hydroxide was the lowest, and the group filled with glass ionomer cement, the group of irritation in that order showed increased concentrations of $LTB_4$ and $LTC_4$ 48 hours after cavity preparation. But no statistically difference was found (p>0.05). 6. The concentrations of $LTB_4$ and $LTC_4$ in all experimental groups were highest level at 6 hour after experiment and decreased as time progresses(correlation coefficient>0.8).

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.10a
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• pp.150-152
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• 2022

In this work, we propose a model that considers the behavior and synaptic plasticity of sensory neurons based on Liquid Time-constant Network (LTC). The neuron connection structure was experimented with four types: the increasing number of neurons, the decreasing number, the decreasing number, and the decreasing number. In this study, we experimented using a time series prediction dataset to see if the performance of the changed model improved compared to LTC. Experimental results show that the application of modeling of sensory neurons does not always bring about performance improvements, but improves performance through proper selection of learning rules depending on the type of dataset. In addition, the connective structure of neurons showed improved performance when it was less than four layers.