• 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.

• Journal of Music and Human Behavior
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• v.1 no.1
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• pp.1-10
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• 2004

Being engaged in the musical tasks needs cognitive skills to perceive musical sound, organize them into meaningful unit, store them in the memory and retrieve them when needed. These skills are also required for academic tasks indicating that there is positive correlation between skills for musical and academic tasks. Based on these findings, the study purported to examine whether the developed sessions can enhance cognitive skills which is composed of auditory information skills, which is composed of perceiving sounds, organizing them into groups based on the existing information or organization pattern, and short-term memory skills. Eighteen elementary students in 4, 5, and 6th grades have participated in the study. The study has administered Music Cognitive Skills Test(MCST) before and after implementing music therapy sessions. The MCST consisted of five parts, first one measuring the rhythm imitating skills, second, measuring the melodic imitation skills, third, measuring discriminative skills in identifying higher pitch, fourth, measuring discriminative skills in identifying identical chords, and lastly, measuring the tone retention skills. The results indicated that there was statistical difference between the pre and post test in rhythm and melody imitation skills. Because reproduction of perceived rhythm patterns requires memory skills, imitating patterns are considered cognitive skills. Also melody is defined adding spatial dimension to the rhythm which is temporal concept. Being able to understand melodic pattern and to reproduce the pattern also requires cognitive skills. The subjects have shown significant improvement in these two areas. In other areas, there were definite increase of scores, however, no significant differences. The study also explores interpretation of these results and also observed consistencies among the participants in completing the musical tasks.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.5
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• pp.517-523
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• 2008

The degradation mechanism of Triclosan(TCS), which is a potent broad-spectrum antimicrobial agent and has been considered as an emerging pollutant, was investigated in the Fenton and the hybrid reaction with Fe$^{2+}$ and UV-C. The results show that the Fe$^{2+}$ is oxidized to 30% by $H_2O_2$, 28% by UV-C, and 15% by UV-A for 10 min. The degradation rate of TCS for beginning time(10 min) was higher in UV-C only reaction than that in hybrid reaction, which of the order was inverted according to the lapse of reaction time. The effect of methanol was the greatest in Fenton reaction, in which the degradation rate of TCS decreased from 90% to 5% by the addition of methanol. Chloride, ionic intermediate, was produced to 77% for 150 min of hybrid reaction(Fe$^{2+}$ + UV-C), which was the greatest. In case with methanol, the generation rate of chloride for 15 min was ignorable in all reactions($\leq$2%) but the hybrid reaction with Fe$^{2+}$ and UV-C(12%). Additionally, the removal rate of TOC in each reaction was estimated as the followed orders; Fe$^{2+}$ + UV-C > Fe$^{2+}$ + $H_2O_2$ > Fe$^{2+}$ + UV-A > UV-C > UV-A. However, the Fenton reaction was almost stopped after 90 min because the reaction between Fe$^{2+}$ and $H_2O_2$ cannot be kept on without adding the oxidant. The phenomena was not observed in the hybrid reaction. In view of generating chloride, the reductive degradation of TCS may be in the hybrid reaction with Fe$^{2+}$ and UV-C, which is favorable to mineralize halogenated organic compounds such as TCS. Consequently, the hybrid process with Fe$^{2+}$ and UV-C may be considered as the alternative treatment method for TCS.

• Journal of the Korea Organic Resources Recycling Association
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• v.11 no.3
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• pp.75-86
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• 2003

In the near future, the capacity of conventional anaerobic digester is thought to be insufficient because of the increase of the total solids from expansion of intercepting sewer, sewage quantity and direct input of night soil from near apartment districts. The objectives of this study was to investigate the improvement of digestion efficiency using microbial agent(Bio-dh). The system was a pilot-scale, two-staged, anaerobic sludge digestion system. The first-stage digester was heated and mixed. The agitation velocity of the first-stage digester was 120rpm. The second-stage digester was neither heated nor mixed. The Digestion temperature was kept at $35{\pm}1^{\circ}C$ The detention time of digester was 19 days. The dosage of sewage sludge and microbial agent were $0.65m^3/day$ and $0.5{\ell}/day$, respectively. The experiments was run for 25days. Three times a week, $COD_{Mn}$ and SS of effluent, TS, VS, and biogas production rate were measured. Temperature, pH, and alkalinity were measured daily. The results were as follows ; Without microbial agent, digestion efficiencies ranged 46.0%~50.9%(mean=48.6%), with microbial agent(Bio-dh), digestion efficiencies ranged 52.8%~57.3%(mean=54.2%). Consequently, microbial agent(Bio-dh) increased the sludge digestion efficiency about 12%. Also, Without microbial agent, the mean concentration of $COD_{Mn}$ and SS of second-stage digester effluent were 1,639mg/L, 4,888mg/L respectively. With microbial agent, the mean concentration of $COD_{Mn}$ and SS of second-stage digester effluent were 859mg/L, 2,405mg/L respectively. Consequently, microbial agent(Bio-dh) increased the removal efficiency of $COD_{Mn}$ and SS about 47.6% and 50.8%, respectively.

• The Korean Journal of Malacology
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• v.27 no.4
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• pp.353-358
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• 2011

This study is the result of examining the growth and survival rate of larva and spat when supplied with Enriched live food by adding $B_{12}$, chitosan, PSB, and polysaccharides to microalgae (Chaetoceros gracilis, Isochrysis galbana) to raise the survival rate of larva and spat during artificial clam seed production. Microalge (Chaetoceros gracilis, Isochrysis galbana) was strengthened for nutrition with $B_{12}$ 0.1 ppm, chitosan 0.2 ppm, PSB 3 ppm and polysaccharides 1 ppm and was daily supplied for $3{\times}10^3-15{\times}10^3Cells/mL$ and the growth and survival rates were measured. As the result of experiment, the growth of larva did not show much difference with PSB test section $199{\pm}0.59{\mu}m$, $B_{12}$ test section $198{\pm}0.64{\mu}m$, and chitosan $197{\pm}0.52{\mu}m$, survival rate was highest at PSB test section with 99.3%, followed by $B_{12}$ test section 95.9%, and chitosan 94.5%. Growth of early spat was the highest for PSB test section at $2.74{\pm}0.58mm$, followed by polysaccharides $2.67{\pm}0.55mm$, $B_{12}$ $2.54{\pm}0.48mm$, and chitosan $2.49{\pm}0.51mm$, and the survival rate was the highest for PSB test group at 32.1%, followed by $B_{12}$ test section 31.6%, chitosan 28.5%, and polysacharrides 21.4%. From such results, PSB is found to be very effective with low-quality improvement when breeding early spat of clams, and especially for floor-type early spat breeding, it had the effect of suppressing protozoan and germs so that detailed studies from various perspectives should be conducted with various chemicals in the future.

• Radiation Oncology Journal
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• v.17 no.1
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• pp.30-35
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• 1999

Purpose : To evaluate the significance of squamous cell carcinoma antigen (SCC) and carcinoembryonic antigen (CEA) as tumor markers in uterine cervix carcinoma. Materials and Methods : In 22 patients with histologically proven primary squamous cell carcinoma of uterine cervix, tumor volume was checked either by using MRI (in 20 patients) or ultrasound (in 2 patients). Pre-treatment serum SCC levels were checked in 22 patients and CEA levels in 21 patients. After curative radiotherapy, post-treatment SCC and CEA were checked regularly. Results : SCC was raised In 68.2$\%$ and CEA was raised in 19.0$\%$ before treatment. The coefficient of correlation between tumor volume and pre-reatment SCC was 0.59382 when one extremely deviated case was excluded. And there was no correlation between tumor volume and CEA. After the treatment, SCC was raised En 9.1$\%$ and CEA was raised in 4.8$\%$. In further follow up measurement, raise of SCC was associated with clinical relapse or persistence of disease. The specificity of raised SCC level in association with recurrent or persistent disease was 93.8$\%$ . The sensitivity in association with recurrent or persistent disease was 100$\%$. The positive predictive values was 85.7$\%$. The median lead time for recurrence was 1.2 months. Conclusions: Both SCC and CEA were good tumor markers for monitoring treatment effect in patients with raised pre-treatment levels. But the sensitivity of pretreatment CEA was low, while that of pretreatment SCC was high. And there was no additional gain by adding CEA measurements to SCC measurements.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.9
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• pp.1243-1252
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• 2009

We investigated a method to improve anticancer activities of Acer mono by ultra high pressure extraction process. The extract yields by ultra high pressure were 9.49% and 9.87% for 5 min and 15 min processing time, respectively, which were relatively higher than 3$\sim$4% of conventional extraction processes due to their resid bark structure. The extract for 15 minutes extraction (HPE15) showed higher potent scavenging effect as 94.56% than the control, BHA as 93.24%. On SOD-like test, HPE15 also showed the highest activity as 38.6% at 1.0 mg/mL concentration. The cytotoxicity of HPE15 on normal human lung and kidney cell were below 23.54% in adding 1.0 mg/mL. Generally, human cancer cell growth stomach adenocarcinoma (AGS), lung adenocarcinoma (A549), breast adenocarcinoma (MCF-7), colon adenocarcinoma (Caco-2) and liver adenocarcinoma (Hep3B) were inhibited up to 75% with higher selectivity of above 4.0. High antioxidant activity of HPE15 resulted in high anticancer activity, and its activity was also due to higher yields of Acer mono by ultra high pressure extraction process. It was also proved by HPLC comparison analysis.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.11 no.5
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• pp.141-151
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• 2016

The purpose of this study is to analyze the effects of the international marketing program (hereunder refer to as 'program') among the programs to support export conducted by the Small and Medium Business Administration. Especially, this study aims to analyze the effects of the program to increase in export for small - medium enterprises of less than 7 years (base on Item 2 of Article 2 of Act on Support for Small and Medium Enterprise Establishment). In order to achieve the purpose above, export result for 1,690 companies which participated through Gyeonggi District Small and Medium Business Administration in 2014 and 2015 were selected among the 843 companies that applied to the program through 12 local small and medium business administration in Korea and quantitative analysis on export performance of 1,690 companies is conducted in this study. In this study, main variables were selected by investigating advanced researches related to export performance of company based on the existing studies. And also, samples have been collected from companies in Gyeonggi area for this research since the companies in Gyeonggi area have been ranked as the 1s annually and the companies in Gyeonggi area employ the highest number of people per industry. As a result of actual proof analysis, Firstly, it was suggested that the program influences positively on the export performance of small-medium enterprises. Secondly, the program shows that the program influenced positively on the export performance of companies with less than 7 years. Lastly, it suggested that the program influenced more positively on the small - medium enterprises with less than 7years than normal small - medium enterprises. By adding the export performances of companies in Ulsan area of which the scale of import and export is the 2nd largest and companies in Seoul area, that participated in the program during the same period, I would like to conduct follow- up research if the significant results are obtained or not.

• The Korean Journal of Food And Nutrition
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• v.17 no.3
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• pp.237-245
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• 2004

The physicochemical and physiological activities of domestic garlic from 3 different areas (Namhae, Jeju and Uiseong) were analyzed. The contents of moisture, ash, crude protein and crude fiber in garlic were little different in 3 kinds of area. Total sugar and water soluble phenolic compounds were higher in garlic from Namhae. The free sugars found in garlic were fructose, sucrose and lactose. Five kinds of organic acids were determined. Malonic acid and citric acid contents in garlic from Namhae were 23.7${\pm}$1.16 mg% and 22.1${\pm}$0.82 mg%, respectively. Total mineral content of garlic samples were in a range of 7112.6～9067.3 mg%, the potassium content showed the highest concentration (4117.3${\pm}$7.19～5175.3${\pm}$9.61 mg%). The electron donating abilities in 0.2% of garlic from Namhae and Uiseong showed 46.2${\pm}$1.25% and 37.0${\pm}$1.l6%, respectively. The nitrite scavenging effect was measured at different conditions (pH 1.2 and 4.2). The nitrite scavenging effects were higher at pH 1.2, and reached more than 95% by adding 0.2% and 0.1 % of garlic juice at pH 1.2. Addition 0.02～0.001 % garlic juice in showed the SOD-like activities. Its activity of garlic from Namhae. was a range of 6.0${\pm}$0.37～14.4～0.69%. It was found that 0.2% and 0.1% garlic showed strong antimicrobial action against growth of all the tested bacteria. Antimicrobial action. was showed 74.7${\pm}$0.70% and 51.7${\pm}$1.l1% on Sal. typhimurium in 0.2% of garlic from Namhae and Uiseong and 28.6${\pm}$0.90% on B. subtilis in garlic from Jeju.

• Food Science of Animal Resources
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• v.24 no.1
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• pp.92-96
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• 2004

pH, Campylobacter spp., Salmonella spp. and Escherichia coli of under-utilized broiler viscera silage added with table sugar during storage at 25$^{\circ}C$ were investigated. pH of silage with 0 and 1 %(w/w) table sugar increased continuously after day 2, but that of 3, 4 and 5% remained 4.0∼4.2 after decrease from 5.2 at day 0. The Campylobacter spp. count of 0% was 8.21 at day 4, however that of 3 and 5% showed 7.56 and 7.38 logCFU/mL, respectively. The Salmonella spp. of 0% maintained 5.8∼6.8 logCFU/mL during fermentation, but that of 3 and 5% was not detected after day 4. The initial E. coli count of silage without table sugar was 5.8 log CFU/mL, but reduced to 4.1 log CFU/mL at day 2, and maintained at the level between 4.0 and 5.0 log CFU/mL, thereafter. However, E. coli was not detected in the silage with 3 and 5% table sugar after day 2. The counts of Campylobacter spp., Salmonella spp. and Escherichia coli of under-utilized broiler viscera silage reduced markedly by adding table sugar. It was proved that the possibility of microbiologically safe broiler offal silage as a potential resource for animal feed materials was improved.