• Food Science and Biotechnology
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• v.18 no.4
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• pp.959-964
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• 2009

Production of the antioxidant substances by Bacillus polyfermenticus SCD was investigated using shake-flask fermentation. The one-factor-at-a-time method was first employed to determine the key ingredients for optimal medium composition, then further investigation of the medium composition was performed using response surface methodology (RSM). The antioxidant activity was measured using 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) assays. After screening various elements, fructose, tryptone, and $MgSO_4\;7H_2O$ were chosen as the main factors for study in the statistical experimental design. Central composite design (CCD) was then used to determine the optimal concentrations of these 3 components. Under the proposed optimized medium containing 2.8% fructose, 1.34% tryptone, 0.015% $MgSO_4\;7H_2O$), 0.5% NaCl, and 0.25% $K_2HPO_4$, the model predicted an antioxidant activity of 80.5% ($R^2=0.9421$. The actual experimental results were in agreement with the prediction.

• Journal of the Korean Society for information Management
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• v.30 no.1
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• pp.71-92
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• 2013

This study compared the everyday-life information behaviors of urban and rural adolescents to suggest ways that school library information services can better meet the information needs of each of these groups. It focused its comparison not only on the everyday-life information-seeking behaviors but also on kinds of information grounds and barriers forming information grounds. Two qualitative methods, written activity logs and semi-structured in-depth interviews, were used to examine everyday-life information behaviors of adolescents. It is expected that the proposed strategies will be used in planning actual school library information services for urban or rural youths.

• Journal of Korean Tunnelling and Underground Space Association
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• v.16 no.6
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• pp.533-542
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• 2014

In this study TBM disc cutter prediction models including Gehring, CSM and NTNU models were investigated and the characteristics of the models were examined. The influence of penetration, uniaxial compressive strength and abrasiveness index on the models was analyzed. The life of disc cutter linearly increases with penetration per revolution and decreases with increasing uniaxial compressive strength of rocks. As the abrasiveness index, CAI, increases, the life of disc cutter in Gehring and CSM model decreases. On the contrary, the life of disc cutter life in NTNU model decreases with increasing CLI. Also, comparisons of predicted disc life were made between models using actual job site data.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.6
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• pp.626-631
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• 2012

In this study, fatigue life of the motor block bracket units for KTX-Sancheon trains was assessed. Design evaluation for railway structures was performed based on the UIC 566 regulation, and test and evaluation of fatigue life in welded parts was performed in accordance with standard ERRI B 12/RP17 and ERRI B 12/RP60. The actual vehicle dynamic stress testing was executed in KTX-Sancheon service line with the service operating speed. The dynamic stress was measured with commercial data acquisition system (MGC plus). The cumulative damage was evaluated by applying standard BS 7608 - Class F and cycle counting was used rain-flow counting method. As a result, the motor block bracket units for KTX-Sancheon trains was designed to fit the regulation and the safety of fatigue life for 30 years, assuming that KTX-Sancheon trains travels 600,000km annually, were confirmed under current operating conditions.

• Journal of the Korean Data and Information Science Society
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• v.23 no.1
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• pp.131-142
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• 2012

Since Korea is moving towards the aged society, increasing is the social attention on overall life satisfaction of the elderly. The purpose of this study is to find the factors affecting the life satisfaction of the elderly among demographic characteristics of aged people, categorized satisfactions and sources of income, based on the 2008 national survey data of the actual living condition of the elderly and welfare need. We found that many factors have significant impact on the life satisfaction of the elderly, such as demographic characteristics, the level of physical and mental health, the economic level.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.114-119
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• 2004

Endbeam is an important structural member of freight bogie for the support of service loading. In general, more than 25 years' durability is necessary. However, endbeam occur fatigue fracture in dynamic stress concentration location because comparatively strength and stiffness are low. Therefore, structure analysis is performed to evaluate structural problem of endbeam and local strain range as durability analysis. The number of cycles is extracted concerning the bogie in operation by measurement dynamic stress time history on critical part which is crack initiation in actual fact. At this time rainflow cycle counting is used to consider change of stress for operating condition. Based on the fatigue life curves and the stress analysis, the fatigue life of the endbeam is predicted and compared with the experimentally determined fatigue life, resulting in a fairly good correlation.

• Management & Information Systems Review
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• v.7
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• pp.227-245
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• 2001

The object that we have researched the design for a long life of product is to search for the method to cope with the various environment problems where our mankind is confronting in the field of Production Design. The environment problem on earth is affecting seriously the enterprise which produces the product, the user who consumes it and even the field of product design. Now we live our daily life with a lot of artifacts while the citification and modernization have been progressing around us. Especially, 20 century was the times of the highly advanced scientific civilization and industrialization. Therefore it affected decisively our life environment base nowadays. The result was that our human life became rich because of the advanced development of industry, productivity and distribution structure. On the other side, the industrial system in the period of these massive production and massive consuming is bearing various problems proportionally. Those are the depletion of resources and energy, earth environmental pollution and various kinds of waste. In addition, the material which cannot recycle is appearing at the large quantity. This is the actuality of now. Our subject is how product design will cope with it as counter measures and the subject is very important to our mankind and earth environment.

• KEPCO Journal on Electric Power and Energy
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• v.8 no.1
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• pp.9-14
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• 2022

Social infrastructure facilities such as production, transportation, gas and electricity facilities may experience poor performance depending on time, load, temperature, etc. and may require maintenance, repair and management as they are used. In particular, in the case of transformers, the process of managing them for the purpose of preventing them from failing is necessary because a failure can cause enormous social damage. The management of transformers should consider both technical and economic aspects and strategic aspects at the same time. Thus, it applies the Asset Management concept, which is widely used in the financial industry as an advanced method of transformer management techniques worldwide. In this paper, the operation and power outage data were secured for the asset management of the transformer for distribution, and the asset status was analyzed. Analysis of asset status using actual operation and power outage data is essential for assessing the statistical life and failure rate of the facility. Through this paper, the status of transformer assets for arbitrary A group distribution was analyzed, and the end of life and replacement life were calculated.

• Journal of Korean Home Economics Education Association
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• v.17 no.3 s.37
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• pp.53-70
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• 2005

This study was to offer a basic data for setting up new curriculum and preparing for effective instruction and education methode on md and nutrition section by researching & analyzing the degree of necessity, difficulty and utilization in actual life of food and nutrition section which requires a close relation with actual life and home economics for the second grade students who studied home economics in the first grade in a middle school. The results obtained were as follows. A highest number of students$(38.9\%)$ responded that 'they learned skills required in home life such as cooking, laundry and childcare' on a question of home economics recognition and the next highest percentage of students$(27.5\%)$ responded' they learned of healthy life and correct human building through home economics education'. For the recognition of a food and nutrition section the highest percentage of students$(38.8\%)$ responded that 'they learned the knowledge and principle of food nutrition for the improvement of a food and nutrition', and the next highest percentage of students$(30.7\%)$ responded 'they teamed practical skills required in actual life'. The meal and nutrition of juvenile, and the principle and practice of cooking was highly ranked in order for the necessity on the food and nutrition section, girl students accounting for higher percentage than boys in overall food and nutrition section and all areas. A nutrition of juvenile, a meal of juvenile, and the principle of cooking and cooking practice was middle ranked in order for the difficulty of the food and nutrition section. Girl students recognized overall food and nutrition section more difficult and also they recognized a nutrition of juvenile and a meal of juvenile more difficult than boy students, but boy students recognized the principle of cooking and cooking practice more difficult than girls. On the practical use of the food and nutrition section in actual life, a meal of juvenile, the principle of cooking and cooking practice, nutrition of juvenile was low ranked in order. Boy students practically used overall food and nutrition section including a meal of juvenile and nutrition of juvenile in detail with high percentage, and girl students practically used the principle of cooking and cooking practice with high percentage. . Regarding interrelation of the degree of necessity, difficultly and utilization on food and nutrition section, as the degree of necessity was high on food and nutrition, the degree of practice was high in all the areas, and as respondents recognized food and nutrition section difficult, they practically used a food and nutrition section at low percentage.

• Journal of Korean society of Dental Hygiene
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• v.6 no.1
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• pp.63-77
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• 2006

The purpose of this study was to prepare a student and education guideline by examining the college life satisfaction of students studying dental hygiene. Subjects were students going to dental hygiene-related department of three colleges in the Gwangju and Jeonnam areas. College life and life satisfaction was examined at general characteristics. The following results were obtained. 1. Subjects included 35.7% of 1st grade, 33.4% of 2nd grade, and 30.9% of 3rd grade. In the health state, average accounted for the highest percent(76.9%); in the student's associates, a little for the highest percent(76.8%); and in the participation in clubs, no participation for the highest percent(77.1%). 2. For motives to select the dental hygiene, good employment after graduation accounted for the highest percent(61.0%). The highest desired employer was a dental clinic(33.5%), and the highest desired duration was a whole life(61.0%). 3. According to the grade, satisfaction was significantly different in social recognition, major in education, professor, facilities, professor-student, career, and college development(pE0.05). 4. According to the school record, satisfaction was significantly different in social recognition, major in education, professor, professor-student, career, college development, and general life(pE0.01). 5. According to the student's associates, satisfaction was significantly different in social recognition, major in education, professor-student, and general life(pE0.01). 6. According to the participation in clubs, satisfaction was significantly different in professor, facilities, college development, and religious life(pE0.05). In conclusion, as students were in the lower grade, made good school record, had happier associates, and participated in clubs more actively, their satisfaction at college life became higher. Accordingly, professors and school authorities should strive to examine students' actual problem and discuss and resolve them in order to help their effective school life.