• Environmental Engineering Research
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• 제19권1호
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• pp.59-66
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• 2014

The aim of this study was to assess the effect of pre-aeration on sludge solubilization and the behaviors of nitrogen, dissolved sulfide, sulfate, and siloxane. The results of this study showed that soluble chemical oxygen demand in sewage sludge could be increased through pre-aeration. The pre-aeration process resulted in a higher methane yield compared to the anaerobic condition (blank). The pre-aeration of sewage sludge, therefore, was shown to be an effective method for enhancing the digestibility of the sewage sludge. In addition, this result confirms that the pre-aeration of sewage sludge prior to its anaerobic digestion accelerates the growth of methanogenic bacteria. Removal rates for $NH_3$-N and T-N increased simultaneously during pre-aeration, indicating simultaneous nitrification and denitrification. The siloxane concentration in sewage sludge decreased by 40% after 96 hr of pre-aeration; in contrast, the sulfide concentration in sewage sludge did not change. Therefore, pre-aeration can be employed as an efficient treatment option to achieve higher methane yield and lower siloxane concentration in sewage sludge. In addition, reduction of nitrogen loading by pre-aeration can reduce operating costs to achieve better effluent water quality in wastewater treatment plant and benefit the anaerobic process by minimizing the toxic effect of ammonia.

• 경영과학
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• 제29권3호
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• pp.23-43
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• 2012

Enacted for enhancing the competitiveness of the Korean capital market and financial industry, Capital Market Consolidation Act (CMCA) was intended to induce considerable changes such as adopting the concept of financial investment products, regulating financial investment functionally, extending financial investors' business areas and intensifying protection for investors. Employing DEA (Data Envelopment Analysis), this study measures and compares the efficiencies of domestic financial companies between the before and after the enactment of the Consolidation Act. We categorize the financial companies into 4 groups (banks, life insurance companies, property and casualty insurance companies and securities companies) depending on their business types, and evaluate how much and in which direction the Consolidation Act affects the efficiency of each group respectively. The study shows that there is no significant difference between the average efficiency of banks and that of property and casualty insurance companies due to the trade-off between opportunities and threats of the Act. To the contrary, it shows that the respective average efficiencies of life insurance companies and securities companies moved in the opposite directions to a considerable extent. Through empirical tests, we demonstrate the effect of the Act on the efficiency of Korean financial companies, and suggest the countermeasures for each financial group against the Act.

• The Journal of Asian Finance, Economics and Business
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• 제6권4호
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• pp.75-81
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• 2019

The paper aims to investigate the linkage among prior financial performance, organizational reputation and earnings quality. Firstly, it examines the influence of prior financial performance on organizational reputation and on earnings quality. Secondly, this research explores the moderating role that prior financial performance plays in the causal relationship from organizational reputation to earnings quality. Thirdly, the mediating role of organizational reputation in the effect of prior financial performance on earnings quality is analyzed. The empirical findings show that, prior financial performance positively affects both earnings quality and organizational reputation that in turn partly mediates the causal connection from prior financial performance to earnings quality; whereas prior financial performance imposes a positive moderation in the influence of organizational reputation on earnings quality. This research is expected to provide scholars and practitioners with a thorough understanding of the complex link among prior financial performance, organizational reputation and earnings quality. That helps them to deliver good decisions on the investment of suitable resources in maintaining and enhancing their organizational reputation, which assures a higher quality of reported earnings that in turn improves involved stakeholders' confidence in their firm. This likely leads the firms to gain better performance in the future.

• 한국환경성돌연변이발암원학회지
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• 제25권2호
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• pp.76-81
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• 2005

25-Hydroxycholesterol (cholest-5-ene-3, 25-diol, 25-OHC) showed the cytotoxicity on HeLa human cervix and NCI-H460 human lung cancer cells, $0.5{\mu}M\;of\;50\%$ inhibitory concentration. We studied 25-OHC as the possibility of radiation sensitizer. The combination effect of 25-OHC and y-irradiation measured using flow cytometer with propidium iodide stained cells. The combined treatment of 25-OHC and $\gamma-irradiation$ did not show significant enhancing effects on Hela and NCI-H460 cells.

• 지역사회간호학회지
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• 제27권4호
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• pp.380-387
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• 2016

Purpose: The purpose of this study was to examine the mediating and moderating effects of fall-related efficacy and social support on the relationship between frailty and health-related quality of life among rural community-dwelling elderly. Methods: A cross-sectional survey was conducted with a convenient sampling method, and data of 438 elderly residents living in a rural community was used. The structured questionnaire included items from the Euro Quality of life-5 Dimensions (mobility, self-care, usual activities, pain/discomfort, anxiety/ depression), fall-related efficacy and social support. Results: Analysis of the mediating effect of fall-related efficacy and social support showed that there was significant mediating influence of fall-related efficacy on the relationship between frailty and health-related quality of life. There were no moderating effects of fall-related efficacy and social support. Conclusion: The findings suggest that fall-related efficacy may play a role in reducing the effect of frailty on health-related quality of life and underscore the need to consider ways of enhancing fall-related efficacy in interventions for rural community-dwelling frail elderly.

• 한국보건간호학회지
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• 제34권2호
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• pp.198-210
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• 2020

Purpose: This study was undertaken to identify the effect of current health conditions and preparation for old age of university students on the awareness of successful aging. Methods: Totally, 273 university students, based across several cities in South Korea, were enrolled for the study. Data collected were analyzed by applying descriptive statistics, independent t-test, one-way ANOVA, Pearson correlation coefficients, and hierarchical multiple regression, using the SPSS Statistics 23.0. Results: There were three types of hierarchical regression model for awareness of successful aging in university students. Its explanatory power of each model was adjusted R² of .04, 07, and .31 respectively. Major (β=.14, p=.007), health condition (β=.13, p=.028), preparation for old age (β=.52, p<.001) were significant predictors of awareness of successful aging. Conclusion: Our study results indicate that for university students, diverse interventions to promote the awareness of successful aging must focus on improving the health condition and enhancing preparation for old age.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2004년도 춘계학술발표회
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• pp.684-691
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• 2004

준설매립 및 연약지반 처리에 있어 압밀촉진 공법들에 대한 연구가 활발하다. 본 연구에서는 초음파를 사용하여 압밀촉진을 유발하고자 하였고 그 영향 정도를 실내실험을 통하여 조사하였다. 실내시험은 특별히 제작된 압밀시험기를 사용하였으며 압밀시험 중 초음파를 시료에 직접 가할 수 있도록 고안되었다. 압밀시험 재료로는 원심력 시험기를 사용하여 원하는 조건에 맞는 동질의 시룔르 제작하여 사용하였으며 초음파 강도, 처리 시간을 달리하여 시험을 실시하였다. 시험결과 초음파가 압밀에 미치는 영향은 큰 것으로 나타났으며 초음파 처리의 영향에 미치는 정도가 시험조건에 따라 다르게 나타났다. 본 연구의 결과를 이용하여 초음파에 의해 압밀촉진을 위한 공법개발의 가능성을 파악하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 춘계학술대회 논문집 디스플레이 광소자 분야
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• pp.45-48
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• 2002

Poly(3-hexylthiophene) or P3HT based organic thin film transistor (OTFT) array was fabricated on flexible poly carbonate substrates and the electrical characteristics were investigated. As the gate dielectric, a dual layer structure of polyimide-$SiO_2$ was used to improve the roughness of $SiO_2$ surface and further enhancing the device performance and also source-drain electrodes were $O_2$ plasma treated for improvement of the electrical properties, such as drain current and field effect mobility. For the active layer, polymer semiconductor, P3HT layer was printed by contact-printing and spin-coating method. The electrical properties of OTFT devices printed by both methods were evaluated for the comparison. Based on the experiments, P3HT-based OTFT array with field effect mobility of 0.02~0.025 $cm^{2}/V{\cdot}s$ and current modulation (or $I_{on}/I_{off}$ ratio) of $10^{3}\sim10^{4}$ was fabricated.

• 중환자간호학회지
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• 제9권1호
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• pp.27-39
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• 2016

Purpose: The purpose of this study lies in investigating nursing and medical staff perceptions on the importance of surgical patient safety protocol, teamwork, and patient safety culture, and how their grasp of the factors affects the degree of their performance of the protocol. Methods: A survey was conducted on 249 nurses and medical staff participating in the operating rooms of one higher general hospital in Seoul, using a 5-point scale self-reported questionnaire. Logistic regression analyses were used. Results: Operating room nurses yielded the highest scores on both the importance of the patient safety protocol and its performance. In patient safety culture, the operating medical staff yielded significantly higher scores than those of operating room nurses. Perception of the importance of the patient safety protocol and teamwork had a significant effect on the nurses' complete performance of the protocol. Conclusion: It is important to create a safety culture, where all the staff can actively and freely communicate with one another through team-based training programs. By enhancing teamwork and patient safety culture, it will be possible to establish the surgical patient safety protocol and to improve the performance of the protocol by health professionals.

• 아시안잔디학회지
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• 제3권2호
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• pp.89-94
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• 1989

Research was conducted to obtain t he optimum treatment Of sodium hypochlorite(NaOC I) at various temperatures in t he seed scarification for stimulating germination of zoysiagrass (Zocysia Japonica Steud ) seed. Morphological changes of seed coat were also examined by scanning electron micros cop(SEM). l. Differences in temperature of scarification with 2 .4% NaOCI showed little influence on promoting germination of seeds but seeds treated with 1% solution at l5˚C germinated less than that of higher temperatures. The promotion effect of 4% solution on germination was diminished when seeds were treated for 8 hours of more. The most favorable seed scarification unaffected hy temperature for enhancing germination was 4-6hours treatment at 4% solution in fresh seeds. 2. $GA_3$, treatment did not enhance germination of water-pretreated control seeds hut germination of seeds pretreated with NaOCI l was increased additional 10% or more hy$ GA_3$, Water pretreated control seeds treated with 50 mM hydrogen peroxide(H'O )germinated about 44%. In NaOCI treated seeds. $H_2$$O_2$ treatment increased germination additional l 0% or more. 3. NaOCI l and KOH treatment softened the seed coat and formed the pores hy removing the scab-like thikenings attached to the seed surface. These results suggest that the modes of action of NaOCl in the promotion of seed germination reside in it increase of the permeability of the seed coat, and in the provision of additional oxygen to the seed.