• Journal of Ocean Engineering and Technology
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• v.13 no.2 s.32
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• pp.99-107
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• 1999

Boiler high-temperature pipelines such as main steam pipe, header and steam drum in fossil power plants are degraded by creep damage due to severe operationg conditions which are high temperature and high pressure for an extended period time. Such material degradation leads to various component failures causing serious accidents at the plants. Conventional measurement techniques such as replica method, electric resistance method, and hardness test method have such disadvantages as complex preparation and measurement procedures, too many control parameters, and therefore, low practicality and they were applied only to component surfaces with good accessibility. In this paper, artificial creep degradation test and ultrasonic measurement for their creep degraded specimens have been carried out for the purpose of evaluation for creep damage which can occur in high-temperature pipeline of fossil power plant. Absolute measuring method of quantitative ultrasonic measurement for material degradation was established, and long term creep degradationtests using life prediction formula were carried out. As a result of ultrasonic tests for crept specimens, we confirmed that the sound velocity decreased and the attenuation coefficient linearly increased in proportion to the increase of creep fractiin(${\phi}$c).

• Korean Journal of Environment and Ecology
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• v.30 no.5
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• pp.908-914
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• 2016

Both interests in nature-friendly education and demands for nature experience program are steadily increasing in children education field in korea. This study aims to find out that five-sense experience-activity with healing factors of forest can have an effect on both self-efficacy and respectful recognition of life of children. 5-year-old young children were chosen as the subjects for this study. Test group participated two times a week in the special forest class in a children education institute in Chungju oo-dong while control group did not. Both test group and control group were composed of 20 young children respectively and each group were 11 boys and 9 girls respectively. The five senses experience activity program was conducted two sessions a week from 8 August to 20 September in 2016 and each session was one hour (60 minutes) long. Five senses experience activity is an activity that young children awaken their five senses in the forest, recognize seasonal change with their five senses, build up their selves and become intimate with nature. Before and after the program self- efficacy test and respectful recognition of life test were conducted and the data was analyzed using SPSS 18.0 program. The results indicated that after participating five senses experience activity program both children's self-efficacy which means having positive-thinking and self-confidence and respectful recognition of life which means valuing nature coexisting with nature were improved significantly(p<0.05). Through five senses experience activity young children felt nature freely and to their heart's content with their bodies and five senses experience activity had better positive impacts on children's self- efficacy and respectful recognition of life than classroom activities.

• Korean Journal of Environmental Biology
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• v.33 no.4
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• pp.468-475
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• 2015

Nonylphenol is one of endocrine disruptors, as structurally stable, hydrophobic compounds exhibit high condensability and long-lasting in the natural environment. The purpose of this study was to determine the toxic effects of nonylphenol on Daphnia magna. In acute toxicity test, D. magna was exposed for 48 h at concentrations of 0, 10, 18, 32, 56 and $100{\mu}g\;L^{-1}$ nonylphenol. In chronic toxicity test, D. magna were exposed through water for 21 days at concentrations of 0, 1.0, 1.8, 3.2, 5.6 and $10{\mu}g\;L^{-1}$ nonylphenol. Acute toxicity was assessed on the basis of immobility, while chronic toxicity was assessed on the basis of fecundity. The acute toxicity test on nonylphenol was showed that the values of 24 h and 48 h $EC_{50}$ were $25.0{\mu}g\;L^{-1}$ and $13.7{\mu}g\;L^{-1}$, respectively. In chronic test, fecundity was reduced significantly at $5.6{\mu}g\;L^{-1}$ of nonylphenol. These results indicated that nonylphenol have some hazard for acute or chronic toxicity to freshwater invertebrate organism.

• BMB Reports
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• v.43 no.12
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• pp.801-806
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• 2010

The existence of glycine residues in long-chain scorpion toxins has been well documented. However, their role as analgesics has not been evaluated. To address this issue, we investigated the functional role of glycines in the C-terminal end of Chinese-scorpion toxin from Buthus martensii Karsch (BmK AGP-SYPU2) using site-directed mutagenesis and analgesic activity assays. Recombinant BmK AGP-SYPU2 and its mutants were efficiently expressed in E. coli and purified to homogeneity using immobilized metal ion affinity chromatography (IMAC) and cation exchange chromatography. The mouse-twisting test was used to detect the analgesic activity of BmK AGP-SYPU2 and its mutants. As a result, we identified glycines at the C-terminal end that, when altered, significantly affected analgesic activity. Also, Mut6566 was significantly decreased compared to BmK AGP-SYPU2. These data indicate that the glycines at the C-terminal end are important for the analgesic activity of BmK AGP-SYPU2.

• Journal of Families and Better Life
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• v.6 no.1
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• pp.189-203
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• 1988

The main objective of this dissertation is to find out the measurement methods of household work organization and manger style and the quantitative analysis methods of influential factors on household work organization and manager style. Subjects were homemakers living in metropolitan , medium and small cities. Questionnaires were sent to subjects and usable responses were 1139 out of 1239 received questionnaires. Data collected through both preliminary and main survey were analyzed by using frequencies, percentage, analysis of variance, chi-square test and pearson's correlation analysis. Results are as follows; 1) The degree of household work organization was distributed on upper middle level exceeding middle score. Among subsystems of household work such as task assignment , test regularization, task arrangement and task standardization. subjects show the highest positive attitude in task standardization. 2) The characteristics of management in household work have task centered orientation. By the prority of task centered orientation, the order was integrated style. dedicated style. It means that the most ideal style is an integrated style which accounts for one-third of the total homemakers. 3) Household organization's subsystems and household work manager style are related with socio-demographic variables. Integrated style is significantly related with homemaker's employment and having helpers for household work. homemakers who are employed and have helpers for household work exhibit high scores in task assignment and task arrangement. Dedicated style is significantly related with homemaker's age and the number of children. Homemakers who are older and have many children exhibit high scores in task assignment. Related style is significantly related with marriage duration, education level and income level. Homemakers who have a long marriage duration exhibit high scores in task assignment and who have high education and income level exhibit high scores in task regularization. Seperates style is significantly related with homemaker's age m marriage duration an family life cycle. homemakers who ar older, have a long marriage duration and are of late stage in family life cycle exhibit seperated style and high scores in organization. To summarize research findings, household work manger and household work organization are related with family life experiences, and task assignment is an influential variable on manager style. in conclusion, it is evident that household work organization emphasizes efficiency as cognitive component and such organization. Finally it is necessary to broaden this research considered social psychological variables. And also it needs to build household manger style models appropriate fro the characteristics of each style.

• Journal of the Ergonomics Society of Korea
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• v.31 no.2
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• pp.379-388
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• 2012

Objective: This study developed a new shower carrier prototype to reduce caregivers' muscle burden and to increase use convenience by reflecting the needs of domestic long-term care institutions. Background: In the long-term care institutions, one of the ADL(Activities of Daily Life) factors is bathing/showering. Recently, bath/shower-assisting equipment is actively being introduced in care institutions to reduce the caregivers' care cost, but most of the domestic equipment was designed to imitate foreign products and rarely reflected the needs of care institutions. Method: Based on Korean elderly people's body information, the bed size(length: 1,900mm, width: 650mm) was set-up, and a variable headrest with a newly designed headform was developed to provide the comfort for the elderly and convenience for caregivers. To reduce caregivers' muscle burden on transferring and showering activities, a 3-step column lifting module equipped with dual actuators(lowest/highest levels from the ground: 600/1,100mm, Stroke: 500mm) was developed, and the wheelbase parameter(length: 1,250mm, width: 580mm) was defined securing the turn-over safety of the shower carrier. The drivability tests were performed for the prototype and foreign product, and the male and female subject's muscle activities were measured through the tests. Results: The structural stability of the shower carrier prototype was secured by finite element analysis, and the muscle activities of the subjects through the drivability tests largely decreased in the prototype, compared to the foreign product. Conclusion: In this study, a new shower carrier prototype was developed to possibly reduce caregivers' muscle burden and to increase use convenience based on the needs of long-term care institutions. It was expected that the drivability performance of the prototype could be relatively superior to that of the foreign product. Application: The results obtained from the study can be applied for the optimal development of a shower carrier including other equipment to effectively care for the elderly.

• Journal of the Korean Society for Nondestructive Testing
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• v.28 no.6
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• pp.512-518
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• 2008

Guided wave technology is advantageous for fast inspection of pipe wall thinning since the guided wave propagates long distance. In this investigation, the method to evaluate gradual wall thinning in a pipe based on the arrival time delay with magnetostrictive patch transducers is presented. Low frequency A0 Lamb waves were generated and measured by the present transducer and it was applied to arrival time delay measurement experiments on a test pipe having gradual wall thinnings artificially manufactured. From experiments, consistent results that wall thinning increases the arrival time delay of A0 waves were obtained. Consequently, the feasibility of the magnetostrictive patch transducers to evaluate wall thinning was verified.

• Journal of Korean Society for Quality Management
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• v.41 no.3
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• pp.327-335
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• 2013

Purpose: The purpose of this study is to suggest the modified 'Korean Standard-Quality Excellence Index' model and analyze the improvement effect with survey data by comparing the properness between current and suggested model result. Methods: The collected data through the survey were analyzed using paired t-test and unbalanced ANOVA method for testing the consistency of two customer satisfaction evaluating categories and comparing the current model to suggested model for confirming the improvement of performance. Results: The statistical analysis result shows that adjusted model using prior information improves the consistency between two customer satisfaction in case of short life-cycle product. Also long life-cycle product case, the result shows difference gap decreasing with same direction. Conclusion: Considering statistical model for QEI reflecting the characteristic of product group such as life cycle seems to be meaningful. Since index may be compared yearly base for checking the trend, careful approaching without big change should be considered for application.

• Food Science and Industry
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• v.51 no.1
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• pp.72-80
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• 2018

Yogurt, which has long been consumed as a longevity food, is characterized by a large number of lactic acid bacteria. The sales of yogurt market have increased for the past three years due to research findings that the intestinal microbial environment is closely associated with many human diseases and the well-being trend of recent consumers. The recent trends in the yogurt market have focused to low sugar content, functionalities such as enhanced immunity, and yogurt for freezing. In addition, recent yogurt products tend to be labeled for certain lactic acid bacteria having functionality in their products. Many yogurts have names of specific lactic acid bacteria on their products, such as 'Activia' and 'Bifidus'. We monitored the 'Bifidus' products in the market for reflecting its regulated counting in their products required to contain more than 10 million Bifidobacteria according to the revised lactic acid bacteria-counting test of Food Code 2015.

• 한국노년학
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• v.36 no.3
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• pp.595-609
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• 2016

The purpose of this study was to test the effectiveness of an eight session self-management support program for improvement of patient activation, joint flexibility and health-related quality of life among medical aid beneficiaries with osteoarthritis. This study was part of a randomized and controlled research of a self-management support intervention. Participants were 60 medical aid beneficiaries who agreed to participate in this study, and were assigned to an experimental group (n=30) or control group (n=30). The 8-session and tailored program led by a trained case manager with the patient-centered approaches and cognitive-emotional-behavioral skills. Analysis included change in scores, ${\chi}^2-test$, Fisher's exact test, t-test and ANCOVA. The results showed significant increase in patient activation, joint flexibility (shoulder and right knee) except health-related quality of life in the experimental group compared to the control group. The self-management support program indicated an effect on patient activation and joint flexibility. Further research is needed to examine the outcome in the long term(9 and 12-month follow up).