• Journal of the Korean Society of Marine Environment & Safety
• /
• v.28 no.7
• /
• pp.1209-1215
• /
• 2022

The selective catalytic reduction (SCR) is known as a very efficient method to reduce nitrogen oxides (NOx) and the catalyst performs reduction from nitrogen oxides (NOx) to nitrogen (N₂) and water vapor (H2O). The catalyst, which is one of the factors determining the performance of the nitrogen oxide (NOx) ruduction method, is known to increase catalyst efficiency as cell density increases. In this study, the reduction characteristics of nitrogen oxides (NOx) under various engine loads investigated. A 100CPSI(60Cell) catalysts was studied through a laboratory-sized simulating device that can simulate the exhaust gas conditions from the power generation engine installed in the training ship SEGERO. The effect of 100CPSI(60Cell) cell density was compared with that of 25.8CPSI(30Cell) cell density that already had NOx reduction data from the SCR manufacturing. The experimental catalysts were honeycomb type and its compositions and materials of V₂O₅-WO₃-TiO₂ were retained, with only change on cell density. As a result, the NOx concentration reduction rate from 100CPSI(60Cell) catalyst was 88.5%, and IMO specific NOx emission was 0.99g/kwh satisfying the IMO Tier III NOx emission requirement. The NOx concentration reduction rate from 25.8CPSI(30Cell) was 78%, and IMO specific NOx emission was 2.00g/kwh. Comparing the NOx concentration reduction rate and emission of 100CPSI(60Cell) and 25.8CPSI(30Cell) catalysts, notably, the NOx concentration reduction rate of 100CPSI(60Cell) catalyst was 10.5% higher and its IMO specific NOx emission was about twice less than that of the 25.8CPSI(30Cell) catalysts. Therefore, an efficient NOx reduction effect can be expected by increasing the cell density of catalysts. In other words, effects to production cost reduction, efficient arrangement of engine room and cargo space can be estimated from the reduced catalyst volume.

• CELLMED
• /
• v.1 no.1
• /
• pp.4.1-4.4
• /
• 2011

Excessive stress is harmful to academic performance in children and may lead to dropping out of school. To meet the demands of a modern life-style which is full of speed, stress and tension, an all-round child health program is crucial. The use of yoga for children has diverse applications in maintaining and developing their physical, mental, intellectual, emotional and spiritual levels. Yoga, through its physical postures (asana), breathing practices (pranayama), cleansing techniques (kriya), meditation therapies (dhyana) and relaxation training (yoga nidra) yields a positive effect in the management of stress in children. Yoga practice benefited children by improving their eye-hand coordination, attention span, levels of concentration, competitive performance and relaxation. Visually impaired children showed a significant decrease in their abnormal anxiety levels when they practiced yoga for three weeks, while a program of physical activity had no such effect. Socially disadvantaged children in a remand home showed significant improvements in sleep, appetite and general well being, as well as a decrease in physiological arousal after yoga. In one study, it is found that a 4-week program of asana and meditation lowers the aggressive behavior of children. Meditation helped to reduce problems related to maladaptive behavior, increase emotional and physical health and psychological well-being in children. Finally, the possible role of yoga in improving the mental state and general well-being of children with cancer is being explored.

• Journal of Environmental Impact Assessment
• /
• v.10 no.1
• /
• pp.1-8
• /
• 2001

Detection of red tides by satellite remote sensing can be done either by detecting enhanced level of chlorophyll pigment or by detecting changes in the spectral composition of pixels. Using chlorophyll concentration, however, is not effective currently due to the facts: 1) Chlorophyll-a is a universal pigment of phytoplankton, and 2) no accurate algorithm for chlorophyll in case 2 water is available yet. Here, red band algorithm, classification and PCA (Principal Component Analysis) techniques were applied for detecting patches of Cochlodinium polykrikoides red tides which occurred in Korean waters in 1995. This dinoflagellate species appears dark red due to the characteristic pigments absorbing lights in the blue and green wavelength most effectively. In the satellite image, the brightness of red tide pixels in all the three visible bands were low making the detection difficult. Red band algorithm is not good for detecting the red tide because of reflectance of suspended sediments. For supervised classification, selecting training area was difficult, while unsupervised classification was not effective in delineating the patches from surrounding pixels. On the other hand, PCA gave a good qualitative discrimination on the distribution compared with actual observation.

• The Mathematical Education
• /
• v.52 no.4
• /
• pp.517-529
• /
• 2013

The purpose of this study is to investigate pre-service teachers' perceptions and their difficulties of mathematics instruction. Pre-service teachers have positive perceptions about teaching students and teaching profession through teaching practicum. In addition, they have perceived that teaching practicum can enhance teaching methods for their students. Especially, they suggested that cooperating teachers' instruction and mathematics teachers and their colleagues' classroom observation are important factors to improve their teaching methods. In other hands, they have difficulties in application of questions encouraging mathematical thinking, attention concentration considering students' interest and planning and performing for mathematics instruction class according to levels of students' study abilities. Based upon this study's findings, teacher education institutes should make efforts to alleviate difficulties in mathematics instruction through effective teaching practicum such as regular reflection activities for their classes, programs development associated with schools, pre-training and education programs for guidance teachers.

• Korea Journal of Hospital Management
• /
• v.7 no.3
• /
• pp.25-43
• /
• 2002

This study focuses on the factors that make the financing decision of private hospitals in Korea. Data used in this study were collected from 98 hospitals with complete general data of current status as well as financial statements. They were chosen from the 138 hospitals that passed the accreditation process by the Korean Hospital Association from 1996 to 2000 for the purpose of accrediting training hospitals. The dependent variables in this study consist of total liabilities to total assets, borrowings to total assets. The independent variables are ownership, hospital type, teaching status, location, bed size, period of establishment, asset structure, profitability, growth, tax shields, volatility of profit, competition(market concentration), and other factors. The major findings of this study are as follows. The factors found to have significant effect on liabilities to total assets are teaching status(-), asset structure(-), profitability(-), tax shields(+), and business risk(-). University hospitals have less liabilities than the non-university hospitals. It was also confirmed that high profitability, high fixed asset, high volatility of profit and low tax shields results in decrease in liabilities. The factors that significantly affect on borrowings to total assets are teaching status(-), period of establishment(-), volatility of profit(-) and competition(+).

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
• /
• 2002.05a
• /
• pp.21-29
• /
• 2002

With regard to the personnel safety and other safety when the gas suppressants are discharged into the area where occupants exist, the short term and long term effects to the health of people are discussed mainly with the Carbon dioxide agent and Halon Replacement agents system. To gain the benefits of CO2 extinguishing systems while minimizing risk to people serious attention must be given to personnel safety in the design, installation, and maintenance of CO2 systems. Training of personnel is essential. A major factor in the use of a clean agent fire suppressant in a normally occupied area is toxicity. While all halocarbon agents are tested for long-term health hazards, the primary endpoint is acute or short-term exposure, The primary acute toxicity effects of the halocarbon agents described here are anesthesia and cardiac sensitization. For inert gases, the primary physiological concern is reduced oxygen concentration.

• Korean Medical Education Review
• /
• v.17 no.2
• /
• pp.60-68
• /
• 2015

The majority of medical educators agree that scientific education is critical to the development of physician-scientists. However, the proportion of physicians interested or engaged in research has been decreasing. To overcome this deficit of research oriented physicians, many medical schools in the United States have introduced scholarly concentration (SC) programs into their medical curricula since 2000. In contrast, Korea has very few medical schools with such programs. Research programs at American medical schools were surveyed and investigated in order to better design and develop SC programs appropriate for Korean medical schools. Information on SC programs was gathered by reviewing medical school web sites and related articles. The SC programs of Brown Alpert Medical School, University of Pittsburgh School of Medicine, Duke University School of Medicine, and Stanford University School of Medicine are discussed in depth. The characteristics of each program were organized into seven parts: program description, administrative structure, orientation, curricular content, mentors and mentoring, student evaluation, and challenges. For a successful SC program in Korea we must consider providing guaranteed time for SC programs with necessary modifications in the core medical curriculum, educating and training of mentors, providing orientation and motivating students to pursue research, developing curricula for SC programs, and evaluating the progress of SC projects.

• Korean Journal of Pharmacognosy
• /
• v.47 no.1
• /
• pp.18-23
• /
• 2016

This study was conducted to investigate the tyrosinase inhibitory and melanin production inhibitory activity of the distilled water extract of Dendropanax morbifera leaf (DMW) and the fermented extract by Lactobacillus plantarum (DMF). DMF was prepared by inoculation of L. plantarum after the extraction procedure with distilled water. Fermentation for 48 hours at $37^{\circ}C$ is the most effective condition in this study. In DPPH radical scavenging ability, $SC_{50}$ values of the fermented DMF was $37.9{\mu}g/ml$ as a result of more effective than DMW extract ($52.6{\mu}g/ml$). Moreover, tyrosinase inhibitory activity of DMF showed higher activity than DMW. In nontoxic concentration range, DMF showed strong melanin production inhibitory effect in ${\alpha}$-melanocyte stimulating hormone-stimulated B16F10 cell. As a result, the fermentation of the distilled water extract of D. morbifera leaf by L. plantarum could be applicable to functional materials production for skin-whitening agents.

• The Korean Journal of Health Service Management
• /
• v.5 no.1
• /
• pp.133-145
• /
• 2011

The purpose of this study is to analyze the influence of external environment, organizational characteristics on informatization level in hospital settings, and to provide suggestions to improve the informatizaiton level of strategic information system of hospitals. In order to achieve study purpose, causal model was developed and empirically tested. Data were collected from 716 managers of 89 hospitals keeping information system in Busan and KyungNam Province using self-administered structured questionnaire. Major results of this study were as follows; First, among hospitals which had information training programs, informatization capacity was significantly higher. Moreover, informatization capacity was significantly varied by ownership type, institutional level, and number of beds of hospitals. Second, environmental uncertainty, intra-industry competition intensity, decision-making concentration, work standardization variables and perceived benefits were found to be significant affecting factors on informatization capacity as a result of path analysis. Third, support of top-management and perceived benefits were found to be significant affecting factors on informatization capability as a result of path analysis. Especially, informatization capability was positively affected by informatization capacity. Finally, perceived benefits was found to be significant affecting factors on informatization competency as a result of path analysis. Especially, informatization competency was positively affected by informatization capability.

• Journal of Korean Academy of Nursing Administration
• /
• v.20 no.3
• /
• pp.281-291
• /
• 2014

Purpose: The purpose of this study was to identify employment experiences of nurses caring for hospitalized foreign patients. Methods: For this study, 10 nurses caring for foreign patients for more than 6 months were chosen purposively. Data were collected through in-depth individual interviews from July to September 2013 and analyzed in terms of Giorgi's phenomenological methodology. Results: Five themes-clusters were identified from fifteen themes; 1) Awesome challenges; 2) Laborious dealing with barriers; 3) Acceptance of cultural differences; 4) Complete concentration of personal energy; 5) Taking a powerful step towards tomorrow. Conclusion: Results of this study reveal the significance of nurses' experiences in caring for foreign patients for the first time in Korea. The following are suggested: First, facilitation and training is necessary for language proficiency, communication skills and ability to understand cultural traits of foreign patients. Second, manuals and international guidelines for caring for foreign patients should be systematically developed to improve quality of healthcare services.