• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.3
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• pp.301-308
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• 2018

This study explores an analytical mathematical model designed to estimate the optimal debt ratio of the Korean automobile industry, which has a more significant effect on the national economy than that of other industries, and attempts to estimate the optimal debt ratio based on objective data. The analytical model is based on ROA and ROE which uses the debt ratio as an independent variable and employs ROS, TAT, and NFCL as the related parameters. Regarding the NFCL, the optimal debt ratio is usually defined as the debt ratio that maximizes the ROA and ROE and is calculated using analytical procedures, such as by adding an equation that considers the debt ratio and the linearity relationship to the analytical model. This is because the optimal debt ratio can be calculated reliably by making use of an estimated value within a certain range, which is derived from more than two calculations rather than a single estimation starting from one calculation formula. In this study, for the estimation of the optimal debt ratio, the ROA and ROE are expressed as a quadratic equation with the debt ratio as the independent variable. Using this analysis procedure, the optimal debt ratio obtained using the data from the Korean automobile industry over a sixteen year period, which would optimize the profitability of the Korean automobile industry, was found to be 188% of the debt ratio in the ROA and 213% of the debt ratio in the ROE. This result was obtained by overcoming the problem of the reliability of the estimation value in spite of the limitations of the logical theory of this study, and can be interpreted as meaning that maintaining a debt ratio of 188% to 213% can enhance the profitability and reduce the risks in the Korean automobile industry. Furthermore, this indicates that the existing debt ratio of the Korean automobile industry is lower than the optimal value within the estimated range. Consequently, it is necessary for corporations to change their future debt ratio policies, given that the purpose of debt ratio management is to maintain safety and increase profitability, and to take into account the characteristics of the specific industry.

• Tuberculosis and Respiratory Diseases
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• v.58 no.5
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• pp.465-472
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• 2005

Background : The survival benefit associated with first-line chemotherapy in lung cancer has led to the need for second-line chemotherapy, for which Docetaxel ($Taxotere^{(R)}$) has proven efficacy in both settings. This study evaluated the safety and efficacy of docetaxel in patients with non-small cell lung cancer who had failed first-line platinum-based chemotherapy. Methods : Thirty one patients with non-small-cell lung cancer, who had failed first-line platinum-based chemotherapy, between March 1999 and August 2003, were enrolled in this study. Patients received intravenous docetaxel, either $75mg/m^2$ or $100mg/m^2$, with routine premedication every three weeks. Results : Fourteen patients (45.2%) had a partial response. The median survival and progression-free survival times were 12.5 months (95% CI 7.3-17.6) and 3.0 months (95% CI 1.6-4.5), respectively. This study showed 2 factors gave different survival benefits; the age (< 60 years: 20.1 months vs. ${\geq}60years$: 6.6 months, p = 0.0105) and the histological type (adenocarcinoma: 25.6 months vs. others: 7.9 months, p=0.0055). The predominant toxicity was neutropenia, which occurred as WHO grade 3 or 4 in 38.7 % of patients. One treatment-related death was also reported. Non-hematological toxicity was minor and easily controlled. There were no significant statistical differences in the survival benefit and toxicity between the two doses. Conclusion : Docetaxel, as second-line monotherapy, was well tolerated and effective in patients with non-small-cell lung cancer who failed first-line platinum-based chemotherapy.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.1
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• pp.94-103
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• 2021

The purpose of this study was to identify the association between regular physical activity (PA) types and metabolic syndrome (MetS) in fertile women. Data were obtained from the seventh Korea National Health and Nutrition Examination Survey (KNHANES VII-3, 2018). The sample consisted of 4,172 fertile women over 19 years of age. The data were analyzed using an independent t-test, χ2 test, and multiple logistic regression analysis for examining the association of regular PA and MetS. The prevalence of MetS in fertile women was 3.1% (n =128), and 1,972 fertile women (47.2%) practiced regular PA. Compared to the non-regular PA group, regular PA resulted in a significantly lower systolic blood pressure (p =.002), lower waist circumference (p <.001), lower fasting blood sugar (p =.007), and higher high-density lipoprotein cholesterol (p <.001). After controlling the confounding variables, multiple logistic regression showed that the regular PA group (odds ratio 0.59, 95% confidence interval 0.35-0.98, p =.040) and the regular muscle-strengthen PA group (odds ratio 0.34, 95% confidence interval 0.14-0.80, p =.013) were associated with a decreased risk of MetS. Therefore, regular PA, including muscle-strengthen PA should be considered to develop effective MetS intervention in fertile women.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.06a
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• pp.97-104
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• 2004

Double-layered polysulfone composite films, containing cerium activated yttrium silicate (CAYS) as a flour, were prepared from double casting of two polymeric solutions, and their morphology and physical strength were superior to those of single-layered composites. The prepared polymeric films consist of a dense bottom layer and a CAYS-holding top layer. The former is made of coagulating the polysulfone and methylene chloride binary solution and works as a supporter to improve the composite's physical strength, while the latter holding the inorganic fluor plays a role as an active site to detect the radioactive contamination. The prepared films revealed two distinguished, but tightly attached, double layers, their attachment being identified by morphology of the interface between two layers. As prepared by water immersion coagulation, the films have highly developed macropores, compared with a dense structure in the film prepared by evaporation. In the radionuclide detection test of the CAYS-impregnated composites, the films have reliable detection capacity at a radionuclide spotting test. The double-layered composites with the dense support layer show a better stability in holding the radionuclides spotted on the surface as well as an improvement in physical strength, compared with the single-layer composites having shortcomings such as being too porous or being brittle.

• Journal of the Korean Society of Urban Environment
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• v.18 no.4
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• pp.495-502
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• 2018

In this study, the AERMOD air diffusing model was used to estimate the range of influence of Hazardous chemicals (hydrogen fluoride) in case of small accidents in Jeju area. The impact scope were in the order of Seogwipo Fire Station, Dongbu Fire Station, Jeju Fire Station, and Seobu Fire Station. Seasonal orders were summer, spring, autumn and winter. The correlation between the meteorological factors shows a strong positive correlation with the wind speed of 0.998 and has a negative correlation with the temperature of -0.463. Through the linear regression analysis, we could estimate the equation of Impact scope = 13.922WS (Wind Speed) - 5.195 and the reliability ($R^2$) was as high as 0.995.

• Journal of Korean Society for Atmospheric Environment
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• v.33 no.3
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• pp.191-204
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• 2017

Concerns on the air pollution problem caused by ambient fine particles have become a big social issue in Korea. Important factors that should be addressed to develop effective and efficient air quality management policy, especially, against fine particles are discussed and research and policy directions to address these factors are suggested. It is suggested that two factors are in high priority; one is scientific understanding of the major formation mechanisms of fine particles and the other is the process of policy decision and implementation. For the scientific understanding, smog chamber measurement, intensive field study, and chemical transport model development that can simulate the characteristics of Northeast Asia are considered to be important. For the policy directions, priority setting of the proposed policies and development and implement of effective communication sytem are considered to be important.

• Korean Journal of Clinical Laboratory Science
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• v.51 no.1
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• pp.93-104
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• 2019

This study examined the relationship between the number of medical technologists and the medical test count. Data was obtained from 441 medical technologists in a hospital through a self-reported questionnaire. The Pearson correlation test, student's t-test, ANOVA or descriptive statistics were performed for data analysis. The distribution of medical technologist according to the size of hospitals was small 5.8, medium 14.9, large 25.8, and super 45.4. The analysis demonstrated a relationship between the number of medical technologists and the number of medical tests in the field, number of clinical tests per MT, and number of optimal medical test per MT according to the hospital size (P<0.001). The average time for quality control by the department at a higher hospital was less than two hours. In terms of the satisfaction of salary, work environment, test accomplishment, and welfare service, the dissatisfaction of medical technologists in small and medium hospitals was higher than those in large and super hospitals. Overall, a focus on intensifying systemic supplementation and improving the condition of medical technologists is needed to provide reliable data for medical examinations in medical areas.

• Korean journal of communication and information
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• v.44
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• pp.108-143
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• 2008

Candidate images refer to a holistic impression of a candidate which is composed of various dimensions of attributes. This study investigated how online and offline news media, campaign media such as political ads, televised debates, and candidate web-sites, and interpersonal political talk influenced voters' images of a candidate in such dimensions as personal traits, job-performance abilities, and policy capabilities, and further their political decision making in the 17th presidential election in Korea. The analysis focused on President Lee, Myung Bak who won the election by obtaining nearly 50% of the effective votes. According to the data analyses, first, uses of offline newspapers positively influenced voters' images of candidate Lee's personal traits such as his morality, integrity, trustworthiness, and compassion, yet online news uses had an opposite effect on voters' impression of his job-performance and economic policy capabilities. Secondly, among various campaign media, television ads and candidate web-sites positively contributed to the formation of candidate Lee's images, yet showed little direct effect on vote choice, indicating that campaign media mainly indirectly influenced voters' political decision making. Each of the first, second, and third televised candidate debates revealed unique effects on image formation and vote choice. Thirdly, the network size and frequency of political talk negatively influenced image formation regarding candidate Lee's personal traits and economic policy capabilities, yet the discussion network size positively contributed to the Lee votes. Forth, among various dimensions of candidate images, voters' perceptions of candidate Lee's personal traits appeared to be the most significant predictor of the support for him.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.8 no.4
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• pp.177-191
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• 2013

6th Industry reduced agricultural income and rural areas, the economic downturn is going to be activated is attracting attention as an alternative. 6th industry means that the integrated or linked, the manufacture and processing of secondary industry based on primary industry, the distribution and service of tertiary industry. Park Geun-hye government to realize the creative economy in agriculture as an alternative to specifically evaluate the 6th industries and suggests various policy alternatives. In addition, to support the development of models and analysis of best practices, including sleep studies are in progress. However, the 6th Industry management body for performing management level, technical level, the leader in comprehensive evaluation of competencies and indicators on the development of an evaluation study is insufficient. In this regard, the present study performed 6th industry management body for the management level, technical level, the leader competency evaluation indicators to develop a comprehensive evaluation by utilizing AHP method was developed indicators. The results achieved in Korea As different countries and the FTA as cheap agricultural imports increased 6th industry revenues associated with the management body is very likely to be worse. The endless competition to survive in the most important of the strategy for each individual project management body to operate on their own, rather than to strengthen internal capacity by strengthening linkages with other industries, products, and services that promote the sale will be. This also is that you need to improve revenue management body. Thus, all 6th industry management body at the location of their efforts to gain the trust of consumers will require, moreover, for each management body to build cooperation between the various measures will be sought. In addition to the smart era rapidly changing needs of customers, depending on the life cycle of products and services are getting faster and the new consumer is getting more and more tend to find new products. Thus, customers and management body 6th industry changes quickly and accurately predict market trends, and also to market new products and services that further efforts would be needed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.12
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• pp.8700-8706
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• 2015

The first driving device of the power bogies for the Korean high-speed railway vehicle consists of the traction motor (TM) and the motor reduction gears unit (MRU). Although TM and MRU are the mechanically integrated structures, their time between overhauls (TBO) have two separate intervals due to different technical requirements(i.e. TBO of MRU: $1.8{\times}10^6km$, TBO of TM: $2.5{\times}10^6km$). Therefore, to reduce the unnecessary number of preventive maintenances, it is important to evaluate the optimal TBO with a viewpoint of reliability-center maintenance towards cost-effective solution. In this study, derived from the field data in maintenance, fault tree analysis and failure rate of the subsystem considering criticality of the components are evaluated respectively. To minimize the conventional total maintenance cost, the same optimal TBO of the components is derived from genetic algorithm considering target reliability and improvement factor. In this algorithm, a chromosome which comprised of each individual is the minimum preventive maintenance interval. The fitness function of the individual in generation is acquired through the formulation using an inverse number of the total maintenance cost. Whereas the lowest common multiple method produces only a four percent reduction compared to what the existing method did, the optimal TBO of them using genetic algorithm is $2.25{\times}10^6$km, which is reduced to about 14% comparing the conventional method.