• Korean Educational Research Journal
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• v.37 no.1
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• pp.103-116
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• 2016

In this study, we examined scientific concept of middle school students about the concept of 'separation of mixtures' Understanding level of students was different by the educational achievement level, and the higher the educational achievement level, the more exactly they understood scientific concept. Misconception was observed at all the achievement level. The higher the achievement level, the common misconception was associated with concept definition. And the lower the achievement level, the common misconception was associated with phenomenon.

• Nuclear Engineering and Technology
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• v.32 no.2
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• pp.157-168
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• 2000

The nuclear steam generator level control system is designed by robust control methods. The feedwater controller is designed by three methods of the H$\infty$, the mixed weight sensitivity and the structured singular value. Then the controller located on the feedback loop of the level control system is designed. For the system performance, the controller of simple PID whose coefficients vary with the power is selected. The simulations show that the system has a good performance with proper stability margins.

• Journal of Korean Society for Quality Management
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• v.38 no.2
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• pp.150-160
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• 2010

Statistics Korea has been diagnosis national statistics every year since 2006. They diagnosis over 200 kinds of national statistics. They have 7 quality dimension used for quality diagnosis. That is relevance, accuracy, Timeliness, Comparability, Coherence, Accessibility. Since we are interest in how well they produce national statistics, comparability has become the most important dimension recently. In this reason, Statistics Korea try to rating quality level and development comparability index for national statistics. This paper propose the practical method of grading the quality level and developing the comparability index of the national statistics.

• Korean Journal of Environmental Agriculture
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• v.27 no.2
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• pp.105-110
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• 2008

The main purpose of this work is the development of water quality level model using the data such as DO, EC, BOD, $COD_{Cr},\;NH_3-N,\;NO_3-N,\;PO_4-P$, T-N, T-P, and SS in 88 agricultural streams of the Han river watersheds. To grant water quality level for each parameters, it divided into 20% respectively in the order of water quality level. On the basis of the lowest water quality level, water quality of streams was assigned. As the result, number of stream corresponding to Level Ⅰ was 0, Level II was 1 stream, Level III was 3 streams, Level IV was 22 streams, and Level V was 62 streams. By standardized canonical discriminant function coefficient, $NO_3-N$ was the highest in 0.427 at the discriminant power. According to discriminant function for water quality level, it was equal to $-4.648+3.246{\times}[NO_3-N],\;-5.084+3.456{\times}[NO_3-N],\;-4.298+3.067{\times}[NO_3-N],\;and\;-7.369+4.396{\times}[NO_3-N]$ from Level II to Level V, respectively. As a result of test at real data of the Han river watersheds in 2007, the suitability of water quality level model was high to 88.4%.

• Journal of agricultural medicine and community health
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• v.27 no.1
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• pp.65-78
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• 2002

This study was conducted to identify the social support to living alone elderly in some rural communities and the level of life satisfaction. For the purpose of this study, face-to-face interviews and questionnaire were performed with 315 old people(male 43 and female 272) aged over 65 living alone in rural communities covered by 14 community health posts within Gyeongsangbuk-do Province randomly selected. The followings are summaries of findings; The average score of support from their children was $4.29{\pm}2.73$ out of 8. Variables that showed a significant difference were religion, level of living, type of medical insurance, frequency of meeting with children, time taken from houses of children by usual means of transportation, and subjective health status. It was found that the score of support from children was high for the elderly who had a religion, a good level of living, benefit from medical insurance, a high frequency of meeting with children, or a good subjective health status, or who resided close to their children's houses. The level of the support from friends and relatives showed a significant difference depending on the subjective health status, of which the average score was $4.13{\pm}2.61$ out of 8. The average score of the level of life satisfaction was $6.83{\pm}4.24$(male $7.60{\pm}4.09$ and female $6.71{\pm}4.26$) out of 17. Male elderly showed the higher level of life satisfaction than female elderly. Variables that showed a statistically significant difference in the level of life satisfaction were religion, level of living, medical insurance, hobby, children, disease, subjective health status, and ADL. That is, the level of satisfaction with life was found to be higher for the elderly who had a religion, a good level of living, benefit from medical insurance, a hobby, children, no diseases, or a good ADL, or who thought that they are healthy. The regression analysis with support from children as a dependent variable showed that the level of support from children was higher for the elderly who had a good level of living, frequency of meeting with children, or a good subjective health status. The regression analysis with the level of support from friends or relatives was higher for old people who had a good level of living. The regression analysis with the level of life satisfaction as a dependent variable showed that the factors which related to the level of satisfaction were sex, religion, level of living, hobby, ADL, and subjective health status. That is, it was found that for male elderly who had a religion, a good level of living or a hobby, or who thought that they were healthy, the level of life satisfaction was higher.

• Journal of the Semiconductor & Display Technology
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• v.20 no.3
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• pp.103-107
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• 2021

In this paper, a capacitive water level sensor for boilers was developed. In order to accurately monitor the water level in a high-temperature boiler that generates a lot of precipitates, the occurrence of precipitates on the surface of the water level sensor should be small, and a sensor capable of measuring even if the sensor surface is somewhat contaminated is required. The capacitive water level sensor has a structure in which one of the two electrodes is insulated with Teflon coating, and the stainless steel package of the water level sensor is brought into contact with the water tank so that the entire water tank becomes another electrode of the water level sensor. A C-V converter that converts the capacitance change of the capacitive water level sensor into a voltage change was developed and integrated with the water level sensor to minimize noise. The performance of the developed capacitive water level sensor was evaluated through measurement.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.6
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• pp.739-745
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• 1998

Sixteen periparturient Holstein cows calving during summer and autumn were fed to meet maintenance plus last 2 month of gestation level of TDN (MP) and 1.2 time of MP level (HMP). Dry matter intake of cows fed at HMP level during summer and autumn decreased by 1 and 2% of the offered feed in 1 week prepartum, respectively, and cows fed at MP level consumed all of the offered feed. Rectal temperatures at 08 : 30 h of cows fed at HMP level were higher than those of cows fed at MP level. Blood hematocrit and hemoglobin of cows increased during summer and were higher for cows fed at HMP level. Plasma total protein and glucose of cows during summer were higher than those during autumn, and the increased feed intake elevated plasma total protein and glucose. Plasma urea-N of cows fed at MP level was higher than that of cows fed at HMP level during autumn. The increased feed intake decreased plasma nonesterified fatty acid of cows during summer and autumn. These results suggest that blood components of periparturient cows are altered by calving season and feeding level.

• Journal of the Korean Chemical Society
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• v.57 no.1
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• pp.127-137
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• 2013

We investigated student's characteristics in each educational achievement level using the results of the NAEA (National Assessment of Educational Achievement) in 2009 and 2010 for Grade 9 students. The analysis of representative items of each educational achievement level revealed that (a) advanced level students could explain the change in phenomena with both the characteristics of matter and the model, (b) proficient level students could explain only simple phenomena with the model, and (c) basic level students did not understand the model and were therefore unable to use it to explain phenomena.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.12
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• pp.110-115
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• 2001

In this paper, a multiple comparison was proposed to minimize the amount of coolant. And new coolant level, called "low level", was suggested to show usefulness of multiple comparison for experiments. The amount of this levee is about 1/4 of conventional coolant amount-called "high level", and dry cutting is called "none level". Using these coolant levels, the cutting temperatures of each coolant level in turning process were analyzed by analysis of variance(ANOYA)-test and a multiple comparison. As the result of ANOVA-test, we have just known that the average of temperature of each coolant level is not equal. However by Tukey's HSD, one of multiple comparison. it was analyzed that the average of temperature of low level is similar to that of high levee and different from that of none level.erent from that of none level.

• Anxiety and mood
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• v.18 no.2
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• pp.92-100
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• 2022

Objective : The purpose of this study was to investigate the association among the fear of COVID-19, depression, risk perception, health belief, and preventive health behaviors related to COVID-19 among university students in Jeonbuk region. Methods : A cross-sectional study was conducted using an online questionnaire survey. The questionnaire included The Korean Version of Fear of COVID-19 Scale, the Korean Version of the Patient Health Questionnaire-9, and measurement tools adapted from previous studies for risk perception, health belief, and preventive health behaviors of subjects. We analyzed data using Pearson's correlation analysis, confirmatory factor analysis, and path analysis using SPSS 22 and AMOS 21. Results : The fear of COVID-19 showed significant positive influence on health belief as well as risk perception. Depression had a significant negative impact on preventive health behaviors and risk perception. Health belief showed a significant positive impact on preventive health behavior. Conclusion : Rresults revealed that the higher the level of depression was, the lower risk perception and performance of preventive health behavior were among university students in Jeonbuk region. As the level of the fear of COVID-19 became higher, the level of health belief and risk perception became higher. The higher the level of health belief was, the higher the performance level of preventive health were. Thus, it is prudent to increase the level of health belief, and lower the level of depression, in promoting preventive health behavior.