• KEPCO Journal on Electric Power and Energy
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• v.4 no.1
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• pp.19-24
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• 2018

The long-term research and development for the production of domestic blades has been consistently performed. As the direct and indirect results of its nationwide technologies in precision casting have been improved as well as maintenance costs for turbine machinery has been reduced. Whereas, there are still not a few concerns about the reliability of newly manufactured blades in spite of the quality certificate in metallurgical and mechanical properties. A spin tester is a machine that gives centrifugal loading to a rotating part, and its practical application is the overspeed test that is usually used to check the quality of products. A new spin rig has been constructed in KEPCO Research Institute for the purpose of evaluating the reliability of blades. In this paper, the test methodology for low cycle fatigue damage mechanism as well as the overspeed test for newly developed blades is described, and their reliability is evaluated too.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.05a
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• pp.18-21
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• 2009

The life of components under high thermal load is typically shorter than other components. The turbopump turbine of liquid rocket is operated under these environments like high temperature and high centrifugal dorce due to high rotating velocity during operating time. These conditions may often cause low-cycle fatigue problem in the turbopump turbine. First of all, to analyze heat stress, ABAQUS/CAE is used and Coffin-manson's equation is used to consider elasticity and plasticity strain. S.W.T's method is used to consider the mean stress effect, using strain history, low-cycle fatigue analysis is done for turbopump turbine which may have FCL(fracture critical location). In this paper, strain life method is applied to analyze low-cycle fatigue.

• Food Science of Animal Resources
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• v.21 no.4
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• pp.323-328
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• 2001

Meat quality of the domestic pork carcasses(n=330) classified in 3 groups according to the Hunter L values postmortem($\leq$50, 50.1∼55.0 and $\geq$55.1) was investigated. The carcass temperature(3, 5, 10 and 15hr postmortem) and temperature falling rate of postmortem increased as the Hunter L value increased. The pH postmortem(pH$\_$ohr/, pH$\_$24hr/) decreased as the Hunter L value decreased. In physical traits, the water holding capacity(WHC) increased and the purge loss decreased as the Hunter L value increased. However, shear force, cooking loss and fat hardness were not significantly different among different. Hunter L value groups(p<0.05). The meat color indices(CIE L*, a*, b*, chroma, hue and ΔE) increased as Hunter L value increased. The sensory characteristics had no significant difference among different Hunter L value groups(p<0.05). In conclusion, the results suggested that Hunter L values were related with pork quality such as temperature, pH, physical traits and color.

• The Journal of Korean Association of Computer Education
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• v.16 no.3
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• pp.79-89
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• 2013

Over the past 10 years, STEAM education uprises to address student's low interest in and self-concept in comparison with their academic achievement in science, reacquaintance to enter schools of natural sciences or engineering. However, There is a paucity of empirical evidence revealing values and necessities of STEAM education in school. The purpose of this investigation is to develop steam education program making and using hands on sensor to experience new technology in school, to apply the program to 110 fourth graders, and to study the effect of the program. Pre- and post-test was used to measure level of student's scientific interest and attitude, scientific problem solving ability, scientific creative problem solving ability, personality test for children, satisfaction of school life. In conclusion, the result show that STEAM education improve every domain of the measurements.

• Fire Science and Engineering
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• v.34 no.3
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• pp.58-66
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• 2020

Households are categorized as exceptions in the Fire Services Act; oftentimes, the 'Golden Time' is missed at the early stages of a fire, resulting in loss of life. As such, due to the high number of deaths caused by household fires, the Korean government amended the Fire Services Act to make it mandatory for all detached houses to be equipped with a fire extinguisher from 2017 onwards. Only 34.8% of households were properly equipped with a fire extinguisher, according to the 2018 factual survey on fire extinguishing facilities in households conducted by the Fire Department. Fire extinguishers are crucial in case of fire but many households avoid them because they are red and have a rough aesthetic, which does not suit the household environment. There is now a need for diverse simple fire extinguisher designs so that they can be used as interior décor in the household in the day-to-day while being available for putting out a fire when necessary. If fire extinguishers have designs that go well with any household space like other decorative ornaments, this will greatly increase consumers' motivation to purchase them. It is greatly anticipated that various companies will work on developing designs for fire extinguishers to commercialize them for households in the future.

• Korean journal of applied entomology
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• v.62 no.3
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• pp.193-205
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• 2023

Botanical insecticides derived from plant extracts exhibit repellent, antifeedant and enzyme-inhibiting activities against insect pests. Among such pests, phytophagous mites are major threats to horticultural crops. Botanical extracts derived from neem, chrysanthemum, and shrubby sophora are employed as field acaricides. These botanical extracts have low toxicities against natural enemies of the insect pests and, thus, are valuable in pest management. This review focuses on the potential for botanical extracts in the controls of mites, with comparisons of the spectrum of activity, the lethal dose and times and their mode of action. This information will enable better formulation of botanical extracts in integrated mite control.

• Journal of Animal Environmental Science
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• v.9 no.2
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• pp.123-130
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• 2003

In this study, current status of domestic deer farms and its feeding were surveyed. The information of supply and demand of feed f3r deers including its industry were also examined and then analyzed to make fundamental data for deer farms and government policy. The results are as follows. 1. Over 40 years old farmers were about 63％ of total deer farms while 20­30 years olds were less than 1％ indicating that young people still evade agriculture. Moreover, considering education, over 52％ of the farmers have bachelor degree showing much higher rates compared to the other agricultural fields. The reason can be assumed that the labor burden is not serious in deer farming while it is not dirty job compared to the other livestock management. Those high­educated people can be easily trained as experts of deer farming to improve its international competition. 2. Most of investigated farms raise Korean spotted deers and Elk showing that the percentage of Elk has greatly increased(However, many farmers have complained about purchasing methods and they insisted that the sales organization should be controlled by government). 3. 57％ of total cost of production is for feed while most of feeds are imported from abroad. It indicated that it is urgent to make counterplan for saving feed cost. 4. It is necessary to develop feeds for deers in the near future while most of the examined farmers currently use normal assorted feed. Typical roughage sources feeds are rice straw, alfalfa hay, browses feed, and so on. Most of them are currently imported except the rice straw indicating urgently needed to develop domestic bulky feed. 5. The present questions are development of processed goods of velvet antler, establishment of reasonable management system, difficulty of velvet antler selling, feed supply, and so on. It is necessary for government and academic world to develop reasonable policy and scientific research program.

• The Journal of the Korea Contents Association
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• v.10 no.9
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• pp.387-398
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• 2010

Recently SMEs(small and medium enterprises) in Korea have experienced severe labor shortages. In particular, college graduates avoiding SMEs are widely spotted. According to previous studies, the main causes of the evasion by college graduates are the inferior working environment and low wages. Some studies also state that SME workers experience discrimination. However, most studies have focused only on unemployment issues of the young graduates. In this research, the results of follow-up surveys on the employment status and job conditions of recent college graduates was linked as a panel data, and the performance of the graduates was analyzed. Based on the analysis, we found college graduates who are employed SMEs are likely to have their initial career fixed to the SMEs. Second, the job separation records of the young SME workers does not show positive labor market performances such as upward movements or wage increases, and the process itself turned out to be entailed frequent separation. Third, the inferior wage level at SMEs and the fact that this effect is cumulatively amplified has been a key factor for evading SMEs. Thus, it is difficult to say that the early-stage careers in SMEs are constructive in future career development. On the contrary, the early careers at SMEs result in lower labor market outcomes, and frequent job separation.

• Korean Journal of Psychosomatic Medicine
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• v.26 no.1
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• pp.9-18
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• 2018

Objectives : The aims of this study were to investigate the psychopathology in adolescents with internalizing disorder using the self-report version of Strengths and Difficulties Questionnaire (SDQ-SR) and the Minnesota Multiphasic Personality Inventory for adolescents (MMPI-A), and to explore the complementarity between these two inventories for diagnostic assessment. Methods : Ninety-one patients aged 13-17 were divided into two groups by clinical diagnosis, 44 with internalizing disorder and 47 comparison group with other disorders. The data of SDQ-SR and MMPI-A completed by them were analyzed for the ability to predict internalizing disorder. Results : The logistic regression analysis revealed that diagnostic predictability increased by 2.27 times with every 1 point of SDQ-SR emotional symptom score increment. Comparison of ROC curves for internalizing disorders showed that the SE and SP of SDQ-SR emotional symptom with score over 4 was 88.94 and 78.72, respectively. For A-anx of MMPI-A with score over 56, SE and SP was 77.27 and 74.47, respectively. However, combination of these scales could not enhance the predictability of diagnostic classification more than that of SDQ-SR emotional symptom alone. Conclusions : Emotional symptom scale of SDQ-SR and A-anx, A-aln, A and INTR of MMPI-A should be important subscales for diagnosing the internalizing disorder of adolescents, however, which needs to be examined further with a larger sample size including normal control group.

• Information Systems Review
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• v.12 no.1
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• pp.165-188
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• 2010

Recently public and finance SI (system integration) industry is called as 4D (difficult, dangerous, dirty, dreamless) industry because of low profit, overtime works and poor motivation of employees. Even some people think at SI industry to be a labor intensive industry instead of a high technology industry. The current study considers outside environmental change of SI industry as well as inside capability enhancement of SI companies. The study adopted action research method with the author's expertise and experiences as a head of a major SI company in Korea. The current research framework suggests 5 areas of profitability enhancement that offers propositions and implications. 5 areas of profitability enhancement are (1) policy improvement, (2) business portfolio innovation (3) sales capability reinforcement, (4) delivery capability reinforcement, and (5) cost management innovation. The five areas include 11 propositional factors and 21 implementation plans which were chosen from the profitability perspectives of SI companies.In order to successfully execute propositions and implementation plans of the framework, 3 years is needed and after 3 years profitability are expected to increase 10% higher than the current level. The framework, propositions and suggestions in this study are expected to offer a real contribution for SI companies that want to enhance competitiveness and profitability. Future extension of the current study to benchmarking the competitiveness and profitability between local companies and global companieswill bring a solid attention from industry and academics.