• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.48-51
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• 2000

The poly(3-hydroxybutyrate) (PHB) synthase of Ralstonia. eutropha, which was produced by a recombinant strain E. coli and purified in one-step with a methyl-HIC column to a purity of more than 90%, was used to polymerize 3-hydroxypropionyl-CoA (3HPCoA) and to copolymerize 3HPCoA with 3-hydroxybutyryl-CoA (3HBCoA) in vitro. A $K_m$ of $189\;{\mu}M$ and a $k_{cat}$ of $10\;sec^{-1}$ were determined for the activity of the enzyme in the polymerization reaction of 3HPCoA based on the assumption that the dimer form of PHB synthase was the active form. Free coenzyme A was found to be a very effective competitive inhibitor for the polymerization of 3HPCoA with a $K_i$ of $85\;{\mu}M$. The maximum degree of conversion of 3HPCoA to polymer was less than 40 %. In the simultaneous copolymerization reactions of these two monomers, both the turnover number for the copolymerization reaction and the maximum degree of conversion of 3HPCoA and 3HBCoA to copolymers increased with an increase in the amount of 3HBCoA in the monomer mixture. However, the maximum conversion of 3HPCoA to a copolymer was less than 35 % regardless of the ratio of 3HPCoA to 3HBCoA. Block copolymers were obtained by the sequential copolymerization of the two monomers and these copolymers had a much narrower molecular weight distribution than those obtained by the simultaneous copolymerization of the same molar ratio of 3HPCoA and 3HBCoA.

• The Journal of the Korea Contents Association
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• v.9 no.6
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• pp.196-206
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• 2009

The profitability of a hospital refers to business administration results achieved through its medical care and other management activities during applicable fiscal year. This study focused on operating margin as a measurement index of hospital profitability, which is a genuine medical return obtained by subtracting medical expenses from medical profits achieved during business administration of hospital. Based on the index, this study could deduce certain factors on hospital profitability in terms of various indices affecting profitability. And based on those factors, this study sought to provide more useful reference materials which allow us to devise possible ways to improve hospital profitability. As a result, it was found that public hospitals attained lower profitability than private ones. To analyze profitability depending on each index, this study divided hospitals broadly into deficit group and surplus group. As a result, it was found that there were significant differences in hospital profitability between two groups depending upon relevant indices such as labor cost ratio, maintenance expense ratio, number of operations per medical specialist and medical instrument turnover. According to analysis on potential effects of relevant indices upon profitability, it was found that each index had its explanatory power ranging from 25% to 74.5% depending on given model.

• Health Policy and Management
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• v.29 no.1
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• pp.27-39
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• 2019

Background: This study is designed to estimate the factors that affect the level of three different performance (publicity, efficiency, profitability) among regional public hospitals. Methods: The units of analysis are the regional 30 hospitals, which have the operating data during 22 years (from 1933 to 2014). The research method is used by fixed panel analysis. The publicity is measured by medicaid outpatient proportion and medicaid inpatient proportion. The efficiency is measured by two types of efficient score by DEA (data envelopment analysis). The profitability is measured by medical income to medical revenue and ROA (return on total asset). Results: At first, the increase of bed gives negative affect to the publicity but give positive effect to the efficiency and profitability. Because it means the increase of the region population, it gives more profitability compare to hospital with small number of beds. The more the operating period is the higher effect to the publicity and efficiency because of it's refutation. The debt ratio gives negative effect to publicity, but positive effect to profitability. It is the normal belief that there is inverse relationship between publicity and profitability. The turnover rate of bed gives the negative affect to the publicity, but positive affect to the efficiency and profitability. That give us the implication that type of the inpatient make different effect the hospital performance. The ratio of labor cost give negative effect to all kind of performance. That means that the higher labor cost don't mean the higher publicity and labor cost control is very important factors to hospital performance. So the region hospital have to focus the labor factors more to make higher performance. Conclusion: As the conclusion, the independent variables give similar effect to the efficiency and the profitability, but give inverse effect to the publicity. That means that if an region hospital want to make the more publicity, it loss the higher efficiency and profitability. Specially publicity is higher negative relation with the profitability.

• Korean Journal of Labor Studies
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• v.23 no.1
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• pp.197-220
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• 2017

This paper provides empirical evidence on the impact of increasing import penetration on the job stability of Korean workers. The main results are as follows. First, import penetration negatively affects job stability. If an industry's ratio of imports to total supply increases by 1 percentage point, the turnover probability of workers in that industry increases by 4.5 percentage points. Second, the effect of trade liberalization is not symmetric between imports and exports. Unlike the case of imports, an industry's ratio of exports to output does not have a significant effect on job stability. Third, the impact of import penetration is not uniform across different types of workers. The negative impact is greater for workers in small firms, less educated workers, and those not protected by labor unions.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.10
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• pp.520-526
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• 2016

This study aims to develop a distress prediction model, in order to evaluate the distress prediction power for first-class hotels and to calculate the average financial ratio in the Seoul area by using the financial ratios of hotels in 2015. The sample data was collected from 19 first-class hotels in Seoul and the financial ratios extracted from 14 of these 19 hotels. The results show firstly that the seven financial ratios, viz. the current ratio, total borrowings and bonds payable to total assets, interest coverage ratio to operating income, operating income to sales, net income to stockholders' equity, ratio of cash flows from operating activities to sales and total assets turnover, enable the top-level corporations to be discriminated from the failed corporations and, secondly, by using these seven financial ratios, a discriminant function which classifies the corporations into top-level and failed ones is estimated by linear multiple discriminant analysis. The accuracy of prediction of this discriminant capability turned out to be 87.9%. The accuracy of the estimates obtained by discriminant analysis indicates that the distress prediction model's distress prediction power is 78.95%. According to the analysis results, hotel management groups which administrate low level corporations need to focus on the classification of these seven financial ratios. Furthermore, hotel corporations have very different financial structures and failure prediction indicators from other industries. In accordance with this finding, for the development of credit evaluation systems for such hotel corporations, there is a need for systems to be developed that reflect hotel corporations' financial features.

• 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.

• Management & Information Systems Review
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• v.38 no.4
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• pp.25-39
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• 2019

The purpose of this study is to analyze the management performance of hospitals by analyzing the ratio of stability, profitability ratio, and growth rate through the financial ratios of medical institutions using accounting information disclosure data of medical institutions, financial status table and profit and loss statement. The main goal is to analyze and analyze financial statements of medical institutions' accounting information in 2016 and 2017, analyze the difference and analyze the general characteristics and financial ratios by type, type and size of medical institutions, The financial characteristics of medical institutions were identified. The ratio of stability, profitability, and growth rate through financial ratios were compared and analyzed. In addition, we analyzed the correlation between the medical profit margin, the total asset profit margin, the medical profit margin rate, and the net profit margin of the medical institutions through the financial ratios of accounting information disclosure data of medical institutions. The main results are as follows: First, the size of the hospital and the size of the debt through the change of assets, liabilities and capital of the financial statement are increasing, the size of own capital is relatively decreased, and the management performance is getting worse It is showing. Second, the increase in average medical revenues in the income statement is small, and the average increase in net profit is small. Thus, medical institutions were able to confirm the difficulty in creating profits through medical activities. In addition, there was a large difference in the debt ratio, the stability ratio, and the profitability ratio of the general hospitals and the general hospitals according to the types of medical institutions, and the difference in the average financial ratios of national and public hospitals, school corporation hospitals, I could confirm. The correlation between independent variables in the correlation was -0.904 between the capital ratio and the total assets turnover ratio, -0.800 between the labor cost ratio and the hospital income ratio, and -0.631 between the labor cost ratio and the foreign profit ratio. In order to improve the management deterioration of hospitals by using accounting information disclosure data of medical institutions, it is necessary to have a large effect on the net profit margin of the medical care and the net profit margin of the total assets.

• Journal of the Korean Association of Geographic Information Studies
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• v.12 no.2
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• pp.23-33
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• 2009

Satellite image is very usefully practiced to predict and analyze physical expansion and change of city. Physical expansion and change of city is closely related to the use of land, and continuous growth management focused on the use of land is essential for sustainable city growth. In this research, the change of land cover and land-use were analyzed with basic input data from 1985 to 2000 according to artificial satellite. Moreover, the land-use turnover rate was understood and expansion trend of urban sprawl in Busan metropolitan city and land-use characteristics of the expansion area. The results are, first, the area for urban region was expanded continuously but areas for agriculture area, forest area, and water area had different changes due to administrative district reform of Busan by each year. Second, the urbanization area in Busan was increased by 3.8% from $92.5km^2$ in 1985 to $167.5km^2$ in 2000. Third, the result of analysis on land-use turnover rate showed that agriculture area was turned into urbanized area the most, and forest area was followed by. Fourth, the result of analysis on database and overlay of buildings in Busan established in 2001 showed that agriculture area are had type 1 and 2 neighborhood living facilities (45.63%), apartment house in forest area (18.49%), and factory in water area (31.84%) with high ratio.

• Journal of dental hygiene science
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• v.14 no.4
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• pp.510-515
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• 2014

Despite the high demand for dental care professionals, high turnover of dental hygienists have been reported, especially among workers in the dental clinics. This study aimed to examine job satisfaction factors affecting dental hygienist's service year in Seoul using cross-sectional data. The questionnaire survey was conducted from August 26, 2013 to September 13, 2013. Data were collected from 296 employees of dental clinics and hospitals located in Seoul. Logistic regression analysis was applied for parameter estimates, using PASW Statistics 18.0 and R software version 3.0.3. The Cronbach's ${\alpha}$ for the total job satisfaction factors was 0.922. In descriptive statistics, the group (that less than four years of working and over four years of working) had a statistically significant difference in age, religion, experience of turnover and autonomous factor among job satisfaction factors. In multiple logistic regression model, autonomy in job satisfaction was an important factor to predict the length of service in dental hygienist (odds ratio, 2.65; 95% confidence interval, 1.06~6.60). Autonomous factor was a significant predictor of length of service for dental hygienist. This study encourages future investigations of the role of job satisfaction of service year using better analytical frameworks.

• Journal of the Korean Geographical Society
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• v.29 no.3
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• pp.340-359
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• 1994

This study intends to describe the characteristics of the transformation of the rural society by tracing the changing social and economic processes of traditional clan villiage (Yeolmi-ri, Silchon-myeon, Kwangju-gun, Kyunggi-province) in the suburbs of Seoul Metropolitan Area. Rural society has experienced serious change of the social structure by the ever expanding urbanization and industrialization since 1960's. The suburbs of Seoul Metropolitan Area is the representative case area of such transformation. This study analyzed various chracteristics of population structure of a villiage, the processes of residential movement and the occupational shift of each household of the villiage in terms of household's life-history collected by interviewing with each household. And the whole households of a villiage is divided by two groups of the native clan group and the non-dan in-migrant group. The results of this study are summarized as follows. 1) This villiage is located within a lineal distance of 40km and a time distance of about 30 to 40 minutes, adjoined dy the Joongbu(중부) national highway, the Kyungchoong (경충) industrial road, the local road between Yangpyuna(양평) and Gonjiam(곤지암) and having a advantageous iocational linkage to Seoul capital city. 2) It is a typical traditional dan villiae constituted of dan family Gu(구) one of whose ancestors had appointed to the prime minister of Chosun Dynasty, and until 1979, 56 out of 60 families of the villiage households were clan families. 3) Since 1979, as the villiage invaded by the out-movement of the small scale manufacturing industries from Seoul capital city, labours moved in this vallige from outside and increased villiage size up to 203 households in 1993, consequently the constitutional proportion between the native clan group and the non-clan in-migrant group was reversed up to 28% vs 72% deepening the sociological heterogeneity. 4) Because of the small scale of industries in this villiage and the vicinity with the city of Seoul, the population turnover of this villiage is very high. The turnover frequency is firstly high within same administrative district of gun(군) level and secondly high between this villiage and the city of Seoul. Thus short-distance movement is identified. 5) There is a close correlation between the residential movement and the occupational shift. The most numbers of non-farm native group have the experiences of migration while the members of native farming group don't shift both the job and the place of residence. The inmigrant group had several migration experiences but few occupational shifts. Thus occupatioanl shift is high for the native group while residential shift is high for the in-migrant group. It is concluded that the change proceeded in Metropolitan suburbs was not directed to form the traditional rural village as 'gesund Gebiet' with respect to the ballance among the economic, cultural and environmental adequency.