• Vacuum Magazine
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• v.2 no.1
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• pp.31-34
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• 2015

This article introduces fundamentals of self-diagnosis and predictive (or preventive) maintenance technologies for dry vacuum pumps. The state variables of dry pumps are addressed, such as the pump and motor body temperatures, consumption currents of main and booster pumps, mechanical vibration, and exhaust pressure, etc. The adaptive parametric models of the state variables of the dry pump are exploited to provide dramatic reduction of data size and computation time for self-diagnosis. Two indicators, the Hotelling's $T^2$ and the sum of squares residuals (Q), are illustrated to be quite effective and successful in diagnosing dry pumps used in the semiconductor processes.

• Journal of the Korea Institute of Military Science and Technology
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• v.3 no.1
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• pp.26-37
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• 2000

This research paper deals with the problem of determining the optimal life time in terms of economical sense for a self-propelled artillery. Equivalent Annual Cost Method(EACM) is used to evaluate the optimal life time, based on the acquisition cost, and the operation and maintenance cost. It is assumed that the operation and maintenance cost includes the costs for spare parts, petroleum and ammunition for training. From the result of this study, the optimal life time for a self-propelled artillery is between 13.9 years and 16.1 years with 95% confidence interval.

• The Journal of the Convergence on Culture Technology
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• v.4 no.2
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• pp.139-147
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• 2018

The purpose of this study was to identify factors affecting maintenance of exercise among elderly with metabolic syndrome. In order to achieve this purpose, the study design was used a cross-sectional survey. Study participants were a total of 136 elderly with metabolic syndrome and they completed the questionnaire consisted of outcome expectations, exercise self-efficacy, exercise social support, physical activity environment, and exercise maintenance. The data was analyzed using frequency, $X^2$, t-test, and Logistic regression by SPSS Win 20.0 program. The study results had shown that factors affecting maintenance of exercise among elderly with metabolic syndrome, were gender, outcome expectation, and exercise self-efficacy. This study results indicated that the personal motivation such as self-efficacy and outcome expectation among elderly with metabolic syndrome was the most important factor to maintain their exercise. Therefore, we should consider on developing health promotion program to enhance the personal motivation such self-efficacy and outcome expectation for elderly with metabolic syndrome. In addition, this results would used to develop adequate nursing strategies for taking care them in the community.

• The Journal of the Convergence on Culture Technology
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• v.9 no.6
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• pp.581-587
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• 2023

The purpose of this study was to analyze the change trajectory and latent class types of self-esteem in first to fourth grade elementary school students. For the purpose, the Korean Children's Panel data were analyzed using potential growth model and the growth mixture model. As the results, the linear change model was selected as the most appropriate model. The change trajectory was found to increase slightly as the grade increased. In addition, four latent class groups were derived through: 'high level-maintenance,' 'low level-increase,' 'high level-decrease,' and 'low level-maintenance.' Most children were in the 'high level-maintenance' group, followed by 'high level-decrease,' 'low level-increase,' and 'low level-maintenance' groups. Therefore, based on the results of the study, we suggest that educational institutions and local communities pay attention to trends in elementary school students' self-esteem and provide appropriate support for students in each class.

• Korean Journal of Adult Nursing
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• v.14 no.1
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• pp.83-92
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• 2002

Purpose: This study was performed to identify the process of change, decisional balance and self-efficacy corresponding to the stage of exercise behavior using Transtheoretical Model in patients with type 2 diabetes mellitus. Method: The study method was a survey in 100 type 2 DM patients at out-patients clinic of Y medical center from March 19, 2000 to October 30, 2000. Result: The results were as follows: The subjects were divided into five stages of exercise behavior ; 15.0% in pre-contemplation stage, 33.0% in contemplation stage, 17.0% in preparation stage, 16.0% in action stage and 19.0% in maintenance stage. The subjects in pre-contemplation stage used all processes of change in the least. "Dramatic relief(DR)", "Environmental reevaluation(ER)" and "Self reevaluation(SR)" were identified as main processes of change in contemplation stage. "Consciousness raising(CR)", "DR" were used higher than average in preparation stage. Helping relationships(HR)", "CR", "ER", "SR", "Social liberation(SL)", "Counter conditioning (CC)", "Reinforcement management(RM)", "Self iberation(SEL)" and "Stimulus control(SC)" were used higher than average in action stage. The subjects in maintenance stage used all process of change the highest except "DR"and "HR". "Cons" score of decisional balance was the highest in pre-contemplation stage, "Pros" score was the highest in action stage and "Self-efficacy" score was the highest in maintenance stage. Conclusion: This study can provide the basis of staged matching exercise program using TTM for more effective and useful intervention.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.3
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• pp.84-89
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• 2018

Recently, study on self-healing materials have been performed to increase the life by repairing the damage of structures themselves, which are difficult to repair or require high maintenance costs. A water permeability test has been widely used for the evaluation of self-healing performance. However, in the self-healing performance test method, the initial crack width of the concrete greatly affects on the self-healing performance but it does not have a consistent standard. Therefore, in this study, the correlation between crack and permeability and that between time and permeability were analyzed based on crack width and permeability. In addition, since the initial crack width measured by optical microscope is not reliable, the value is derived from the Poiseuille flow and the tendency of time-permeability and time-crack width are analyzed.

• Nutrition Research and Practice
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• v.11 no.4
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• pp.340-346
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• 2017

BACKGROUND/OBJECTIVES: Despite the importance of consuming sufficient amounts of vegetables, daily vegetable intake among adolescents in Korea is lower than the current dietary recommendation. The objective of this study was to examine determinants affecting vegetable preference in order to suggest a stage-tailored education strategy that can promote vegetable consumption in adolescents. SUBJECTS/METHODS: Adolescents (n = 400, aged 16-17 years) from two high schools participated in a cross-sectional study. Survey variables were vegetable preference, the social cognitive theory (SCT) and stages of change (SOC) constructs. Based on vegetable preference, subjects were classified into two groups: a low-preference group (LPG) and a high-preference group (HPG). SOC was subdivided into pre-action and action/maintenance stages. To compare SCT components and SOC related to vegetable preference, chi-squared and t-tests, along with stepwise multiple-regression analysis, were applied. RESULTS: In the LPG, a similar number of subjects were classified into each stage. Significant differences in self-efficacy, affective attitudes, and vegetable accessibility at home and school were detected among the stages. Subjects in the HPG were mainly at the maintenance stage (81%), and there were significant differences among the stages regarding self-efficacy, affective attitudes, and parenting practice. In the predictions of vegetable preference, self-efficacy and parenting practice had a significant effect in the "pre-action" stage. In the action/maintenance stage, outcome expectation, affective attitudes, and vegetable accessibility at school had significant predictive value. In predicting the vegetable preference for all subjects, 42.8% of the predictive variance was accounted for by affective attitudes, self-efficacy, and vegetable accessibility at school. CONCLUSION: The study revealed that different determinants affect adolescent vegetable preference in each stage. Self-efficacy and affective attitudes are important determinants affecting vegetable preference. Additionally, school-based nutrition intervention that focuses on enhancing affective attitudes, self-efficacy, and vegetable exposure may constitute an effective education strategy for promoting vegetable consumption among adolescents.

• Journal of the Korea Society for Simulation
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• v.23 no.2
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• pp.73-84
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• 2014

Recently, researches on the application of IT technology to various fields including traditional industries are becoming more popular. One challenge in the field of education is to understand the way how technology may support learning, and research on self-directed learning has been accelerated by integrating education and IT technology. The process of self-directed learning in e-learning applications such as Car Maintenance Training is very difficult and complicated. Previous studies on car maintenance training applications provided simple training scenarios with predetermined action sequences. To incorporate self-directed learning in car maintenance training, however, trainees must be able to perform various maintenance operations himself and experience various situations. To provide such functionality, it is necessary to obtain an accurate response for various operations of trainees, but it requires complicated calculations with respect to varieties in the electrical and mechanical processes of a car. In this paper, we develop a logic simulation agent using JESS inference engine in which self-directed learning is achieved by capturing the behavior of trainees and simulating car operations without complicated physical simulations in car maintenance training.

• Korean Journal of Community Nutrition
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• v.13 no.5
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• pp.653-662
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• 2008

This study has been performed to analyze nutrition knowledge, dietary self-efficacy and eating habits of the elementary- and middle- school students (n = 342) according to student's stage of regular breakfast or exercise. Middle school students had higher nutrition knowledge than primary school students. Total dietary self-efficacy and dietary habit scores were not different by school year and gender. Nutrition knowledge, dietary self-efficacy and dietary habit scores were positively correlated each other. By the stage of regular breakfast, the pre-contemplation stage comprised 13.6%, contemplation 2.1%, preparation 15.7%, action 11.5% and maintenance stage 59.1%. By the stage of regular exercise, the pre-contemplation stage comprised 20.9%, contemplation 7.3%, preparation 45.6%, action 9.8% and maintenance stage 16.4%. According to the stage of change, movement from the pre-contemplation and contemplation to upper stage increased the dietary self-efficacy score. Dietary habit score increased significantly across the five stages of changes. The results of this study indicate differences in stages of changes in breakfast intake and regular exercise and indicate the need for taking these phases of change into account in nutrition education.

• Journal of the Korea institute for structural maintenance and inspection
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• v.11 no.1
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• pp.113-120
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• 2007

A new material was tested and its applicability was investigated so as to give the capability of self-diagnosis of fracture in composite mortar. In the research for giving self-diagnosis capability, conductive mortar intermixed with cokes and carbon fiber powder(milled carbon fiber) was developed and its using for self-diagnosis material was proposed. Then after examining change in the value of electric resistance and AE characteristics before and after the occurrence of cracks at each weight-stage, the relationships of each factors were analyzed. As the results, it can be recognized that a new composite material with cokes and carbon fiber powder(milled carbon fiber) can be applied for self-diagnosis of fracture in mortar specimen.