• Journal of Dental Rehabilitation and Applied Science
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• v.28 no.2
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• pp.139-145
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• 2012

The purpose of this study was to evaluate the accuracy of Root ZX and Sybron Mini in determining the working length using 2.5% Sodium Hypochlorite, 2% Chlorhexidine gel and saline. Donnelly's gelatin technique was used for measuring twenty extracted human teeth. Electronic working length was measured at the display 0.5 and 0.0 level of each electronic apex locator using a digital caliper to the nearest 0.01 mm. Each measurement was repeated for each different irrigants. Accuracy of Sybron Mini was not significantly different from the Root ZX in the three different irrigants, and there was no significant difference in the accuracy of electronic apex locators among the irrigants when used as recommended by manufacturer (measuring electronic working length at 0.0 level of Sybron Mini and at 0.5 level of Root ZX).

• Journal of Fisheries and Marine Sciences Education
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• v.24 no.6
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• pp.977-988
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• 2012

The purpose of this study was to help teachers increase the level of student's school life satisfaction by comparing between the practical data of a group which have an accordant perception for class teacher's discipline style perceived by between teacher him/herself and student with another group which have a discordant perception for class teacher's discipline style perceived by between teacher him/herself and student. For this study, 1460 second grade special high school students in Pusan were selected. And 1273 students and 56 teachers' questionnaires were used for analysis, while 5 questionnaires went uncompleted. T-test and Multiple Regression Analysis were used for compiling statistics of collected data. The results of this study are as follows: First, perceptions about the teacher's discipline style perceived by between teacher him/herself and student were different. Second, the levels of student's school life satisfactions were different by two group. A group which has an accordant perception for class teacher's discipline style perceived by teacher him/herself and student shows the high level of school life satisfaction than B group which has an discordant perception. Last, class teacher's discipline style which affects the level of student's school life satisfaction was different by the two group. These results suggest that to increase the level of student's school life satisfaction, class teachers have to a mutual understanding first, and then approach their students with different discipline style by the level of their interactive relationship with their students.

• Journal of Biomedical Engineering Research
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• v.18 no.4
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• pp.485-491
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• 1997

This paper describes the relationship between skin impedance signal, behavioral signal, and subjective evaluation depending on arousal level. Nz and reaction time had similar trend with mKSS level, but eyeblink rate was different from these two parameters. eye-blink rate increased slowly from mKSS level 1 to 5, and had high increasing rate at mKSS 7. But it showed steep descent at mKSS level 9. Each subject showed different eye-blink rates, but changing rates of EBR was similar at eachm KSS level. Therefore it suggests that rising rate of EBR can be used arousal level criterion. From the result of reaction time test. human performance was decreased rapidly above the mKSS level 5, and false positive and false negative data was observed above the mKSS level 3. It is desirable to give a subject some stimuli such as sound or aroma to rise arousal level between mKSS level 3 and mKSS level 5.

• Environmental Engineering Research
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• v.10 no.3
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• pp.105-111
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• 2005

The applicability of the USEPA's (United States Environmental Protection Agency) three criteria of enhanced coagulation (criterion 1-TOC level less than 2 mg/l. before chlorination; criterion II-% requirement of TOC removal; criterion III-point of diminishing return) for Korean waters was evaluated in this study. This study also investigated an effect of enhanced coagulation on turbidity removal, and attempted to identify the best coagulant for enhanced coagulation. Three different waters were used in this study: one river water and two lake waters. five different coagulants were used: alum, liquid alum, PACl, ferric chloride with and without water. Results of this study showed that all three criteria were achievable for the tested waters. For these waters, controlling criterion was found to be different depending upon raw water characteristics. When initial Toe level was low(< 4 mg/L), criterion I (< 2 mg/L) could be the controlling criterion. As TOC level increased, criterion II (% TOC removal) became the controlling criteria. It was possible to achieve different goals of turbidity and TOC removals. Although the optimum region of TOC removal was more acidic than that of turbidity removal, there was no conflict between these two removals. The best coagulant was found to be different depending upon the evaluation tool: maximum and optimum removal. ferric chloride was more effective than alum in terms of the maximum TOC removal, while Al-based coagulant such as alum or PACl was the best coagulant in terms of the optimum TOC removal.

• Women's Health Nursing
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• v.5 no.3
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• pp.389-409
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• 1999

This study was carried out to identify the differences between nursing needs and levels of satisfaction of postpartum women during the early postpartum period. The goal of this study was to obtain needed to develope the nursing quality for postpartum women. The subjects were 87 postpartum women who had vaginal delivery at 2 general hospital and 2 maternity hospital in the Ulsan City. The period for the data collection was from June 1 to 29, 1999. The data was gathered using an 98 items questionnaire which was a modified version of a questionnaire the developed by Y. J. Chun. Results found are as follows : 1. The general characteristics of the subjects : The majority of subjects were 25-29 yrs. (57.5%), high school and college graduates(96.5%), unemployed(75.9%), middle ranged economics(93.1%), had no religion(43.7%), male baby(52.9%), birth weight 3-3.5Kg(49.4%), wanted pregnancy(96.6%), no abortion history(50.6%), had antenatal care(89.7%), had prenatal education(32.2%), postnatal education(42.5%), intended breast feeding (46.0%), had resonable self confidence about self(20.7%), infant care(36.8%) and nuclear family pattern(82.3%). 2. The level of nursing needs of overall nursing care(3.93) and the levels of satisfaction(3.86) was relatively high. The nursing needs by category of nursing care, the highest need was in the emotional and psychological care(4.09), and the lowest need was in physical need(3.73). The satisfactions by category of nursing care, the highest satisfaction was in emotional and psychological care(4.11) and the lowest satisfaction was in education in self care(3.64). The significant differences between nursing needs and satisfactions were found on education in infant care(p=.005), and education in self care(p=.020). 3. Among items of physical care, 'accurate medication and treatment(4.21)', 'control of postpartum hemorrhage(4.13)', 'pain control and care of episiotomy wound (4.12)' and 'regular observation of postpartum conditions(4.09)' showed high nursing needs. 'Accurate medication and treatment(4.31)', 'regular observation of postpartum condition(4.24)', 'control of postpartum hemorrhage(4.22)' and 'pain control and care of episiotomy wound(4.12)' showed high satisfaction levels. 4. Among items of emotional and psychological care, 'personal treatment(4.32)', kind and faithful care(4.30)', 'detailed explanation on the treatment or nursing care(4.25)', 'adequate draping during the care and treatment(4.23)' and detailed explanation on a doubt(4.13)', showed high nursing needs, 'personal treatment(4.52)', 'kind and faithful care(4.45)', 'detailed explanation on a doubt(4.24)', 'detailed explanation on the treatment or nursing care(4.21)' and 'adequate draping during the care and treatment(4.18)' showed high satisfaction of nursing care. Difference between the level of nursing needs and satisfaction was significant except item of 'early contacts with their baby and breast feeding'. 5. Among items of environmental care, the highest level of need and satisfaction were on the items of 'neat bedding and clothes(4.05, 4.21)' and 'room cleansing or care of room(4.01, 4.28)'. Differences between the level of nursing care and satisfaction were 'room cleansing of care of room'. 6. Among items of educational needs on self care, 'sitz bath method(4.22)', 'high risk symptoms to immediate clinic visits(4.13)', 'the timing of tub bath(4.05)' and 'good secretion of breast milk(4.03)', showed high nursing needs, 'sitz bath method(4.22)' showed high satisfaction of nursing care. Differences between the level of nursing care and satisfaction were 'the timing of hair shampoo', 'the timing of tub bath', ' the method of pad change', 'postpartum exercise', 'good secretion of breast milk', 'maintenance of breast figure', 'contraindicated drugs in postpartum women', 'kegel exercise' and 'breast self examination'. 7. Among items of educational needs on infant care, 'immunization of infants(4.36)', 'symptoms of sickness to immediate clinic visits(4.28)'. 'safety and emergency care(4.28)', 'umbilical care(4.26)', 'feeding times and intervals(4.24)', 'normal growth and development of infant(4.24)' and 'infection control(4.22)', showed high level of nursing care, 'immunization of infants(4.21)', 'feeding times and intervals(4.17)', were high satisfaction items showed significant differences between the level of nursing care and satisfaction. 8. Relationship between nursing needs and levels of satisfaction among postpartum women were as follows : 1) Physical area : There were no significant differences in the level of nursing needs, but satisfaction levels were significantly different among 'working mothers', 'baby's weights', 'baby's sex', 'planning of feeding' and 'routes of receiving postpartum informations'. 2) Emotional and psychological area : The level of nursing needs were significantly different in the area of 'confidence in self care'. Satisfaction levels were significantly different among 'baby's sex', 'baby's weights', 'the confidence of infant care' and 'working mother'. 3) Environment area : There were on significant differences in the level of nursing needs, but satisfaction levels were significantly different among 'maternal age' and 'baby's weights'. 4) Education in self care : The level of nursing needs were significantly different among 'parity history' and 'type of family formation'. Satisfaction levels were significantly different among 'working mother', 'baby's sex', 'antenatal care', 'postpartum education', 'planning of feeding', 'routes of receiving postpartum informations'. 5) Education in infant care area : The level of nursing needs were significantly different among 'parity history'. Satisfaction levels were significantly different among 'baby's sex', 'receiving postpartum education or not' and 'working mother'.

• Journal of the Korea Society of Computer and Information
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• v.6 no.3
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• pp.102-112
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• 2001

The purpose of this study is to suggest a direction of a investment policy to increase a competitive power for small firms. For this purpose, several hypothesis are established and tested (1) Whether the small firm's management resources and performance are different among industries\ulcorner (2) What resurces affect on the business performance\ulcorner (3) Whether the firm's management resources which affect the performance are different among industries\ulcorner (4) Whether the firm's resources level are different between high performance group and low performance group in same industry\ulcorner For the empirical study, the data is obtained from 1,338 small firms in Korea manufacturing industries. The results of this study are (1) the level of firm's management resources and performance are different among industries and (2) the management resources which affect the performance are different according the industry. And (3) the management resources level are different according to the firm's performance level in some industry.

• Journal of Information Technology Services
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• v.18 no.5
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• pp.31-51
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• 2019

Construal level theory (CLT) have been researched in wide range of disciplines such as marketing, organizational study, psychology, or education. Current study asserts that CLT would explain the effect of different devices of PC and smartphone on interaction between human-computer interfaces and information systems use. In CLT, those who are far from an object in terms of physical, temporal, social or psychological distance, they construe their understanding as abstract (high level) and vice versa. We hypothesized different size of digital device will increase psychological distance and result in behaviors that correspond to present construal level. The analysis result shows that users of PC recognized that they are socially distant from the device and those of smartphone felt that they are socially close to the device. However, the device did not have significant effect on attention to essential information, advertisement preference, and immediacy. The implication to academia, practice and future research and limitations are also discussed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.371-376
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• 2003

The objective of this paper is to compare the site-to-site variability of ISO 10844 pass-by-noise test sites. In order to investigate the site-to-site variance of test surfaces, European commercial tires are tested at seven different test sites. Three Korea test sites and four Europe test sites are selected.. The pass by noise test is executed according to a 2001/43/EC regulation. A]though the ISO surface has a very specific track composition, it does not reduce the variation of pass-by-noise measurements over the surface of test sites. This paper shows that the test results of pass-by-noise level are different depending on the test sites. The correlation obtained in this work is able to predict the pass by noise level for certain test site using the data measured from another test site. 17he prediction value is range with an error within 1dB(A).

• Journal of Korean Institute of Industrial Engineers
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• v.43 no.2
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• pp.135-146
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• 2017

This paper considers redundancy optimization problems of multi-level systems and reviews existing papers which proposed various optimization models and used different algorithms in this research area. Three different mathematical models are studied: Multi-level redundancy allocation (MRAP), multiple multi-level redundancy allocation, and availability-based MRAP models. Many meta-heuristics are applied to find optimal solutions in the several optimization problems. We summarized key idea of meta-heuristics applied to the existing MARP problems. Two extended models (MRAP with interval reliability of units and an integrated optimization problem of MRAP and preventive maintenance) are studied and further research ideas are discussed.

• Korean Journal of Community Nutrition
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• v.10 no.1
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• pp.59-69
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• 2005

The purpose of this study was to estimate the mineral intakes and serum mineral levels of pregnant and lactating women. The subjects consisted of 34 non-pregnant, 56 pregnant and 20 lactating women. Nutrients intakes were investigated by the 24-hr recall method, and serum major and trace minerals were analyzed by the ICP-spectrometry. Calcium (Ca) and zinc (Zn) intakes were observed lower than RDA especially for both pregnant and lactating women. Iron (Fe) intake of pregnant women was $85 - 139\%$ RDA through Fe supplementation, and that of lactating women was lower than RDA. Compared with non-pregnant women, the pregnant women had similar Ca intake and higher magnesium (Mg) intake. Comparing with the non-pregnant women, serum Ca level in pregnancy was lower, and that of lactating women was not significantly different. Serum phosphorus and Mg levels were not significantly different among the groups. Serum Fe level of pregnant and lactating women was lower than that of the non-pregnant women. Serum Zn level of pregnant women was lower than those in the lactating and non-pregnant women. Serum copper level decreased as the pregnancy progressed. Serum sodium (Na) level was higher in 2nd- and 3rd trimester and potassium (K) level was higher in 3rd trimester and lactating period than other groups. Na/K ratio was not significantly different among the groups. During all periods, there was no correlation between dietary intakes and serum levels in each minerals. Serum Ca level positively corrleated with serum Mg level, especially in 3rd trimester and lactating women. In general, serum mineral levels in pregnancy were changed compared to the levels in non-pregnancy and restored in lactation to the levels for non-pregnancy.