• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.4
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• pp.89-95
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• 2013

In this work, the evaluation of swirl nozzle injector performance was conducted by investigating effective area ($A_{eff}$), injection mass ($m_{inj}$), injection rate ($Q_{inj}$), and injection delay ($t_{delay}$) under various test conditions. To achieve these, fuel injection analysis system which was composed of fuel supply system, injection system, and control system was installed. At the same time, the swirl nozzle that had 12 orifice hole with $120^{\circ}$ injection angle was used in this work. It was revealed that the difference of injection mass ($m_{inj}$) between base and swirl nozzle injector increased as the injection pressure ($P_{inj}$) and energizing duration ($t_{eng}$) decreased under the same test conditions. The maximum injection rate ($Q_{inj}$) of swirl nozzle injector was higher than base nozzle injector about 2~5%. The injection performance of swirl nozzle was better than base nozzle at low injection pressure ($P_{inj}$) and short energizing duration ($t_{eng}$) conditions.

• The Journal of the Korea Contents Association
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• v.18 no.7
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• pp.221-228
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• 2018

This study aimed to analysis the effect of parenting behaviors on young children's social competence. The data of 1408 child 72-79 months and their parents were extracted from the 7th Panel Study on Korean Children in 2014 by Korean Instute of Child Care and Education. The data were analyzed with descriptive statistics, t-test, and the multiple regression analysis. The research results were as follow: First, there was a significant difference in social competence of young children according to gender and mother's parenting behaviors and father's warmth parenting behaviors. Second, mother's warmth and control parenting behaviors and father's warmth parenting behaviors influenced young children's social competence. But, father's control parenting behaviors didn't influenced the social competence of their children. After discussing these and then a conclusion and proposal were presented.

• Journal of the Korean Society for information Management
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• v.17 no.3
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• pp.125-146
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• 2000

This study is to maximize the efficiency of university libraries' human resources management by determining the followings : the relationship between the level of information technology(1T) implement and the job satisfaction of the librarians, the main factors that affect job satisfaction, and how organizational characteristics and individual characteristics affect job satisfaction. Questionnaire was sent to 485 librarians from 27 universities chosen by stratified sampling and the methods of ANOVA, T-test, and correlation analysis were used. The results of the analysis are as follows. 1) there is a significant difference in the level of job satisfaction and the motivation factor according to the level of implementation of IT. 2) There is a relatively high correlation among the participation in decision making, the leadership in implementing the IT, the IT support of the CEO and job satisfaction. 3) There is a significant difference in job satisfaction by the level of computer skills, and a relatively high correlation is shown in the training experience while implementing the IT and job satisfaction.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.26 no.5
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• pp.519-526
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• 2000

Osteoporosis has recently been recognized as a major health problem in the elderly population. The disorder is manifested as a loss of bone mass accompanied by structural alteration of bone and increased incidence of fracture. Mandible also may be affected. So, I evaluated panoramic views of 66 postmenopausal women for finding the possibility of useful diagnostic mandibular parmeters of osteoporosis. To know the correlationship between skeleton and mandible, the average of the bone mineral density of lumbar from 2nd to 4th by the dual energy X-ray absorptiometry(DEXA, LUNAR DPZ. USA), and age and mandibular parameters, that is, the number of residual teeth, alveolar ridge resorption ratio, panoramic mandibular index (PMI), mandibular cortical width (MCW), angular cortical thickness (ACT), ramus cortical thickness (RCT), morphology of mandibular inferior cortical (MIC) were compared. And I divided the all tested women to the osteoporotic group and non-osteoporotic group by the use of T-score -2.0, which was derived from skeletal bone mineral density (BMD). To find the correlationship of the each group with mandibular parameters, t-test and discriminant analysis were done. The results of the t-test were that all parameters were highly related with 2 groups (p<0.05). Especially ACT, MIC, age have had even higher correlationship than others (p<0.001). The results of the discriminant analysis by the use of these ACT, MIC and age were that the discriminant function was Z = -2.973+(-1.447)$\times$(ACT)+1.131$\times$(MIC score)+(0.052)$\times$(age), the cutting score was 0.257 and the classification accuracy was 84.8%. Therefore I suggest that the consideration of the angular cortical thickness (ACT), the age of patient and the morphology of mandibular inferior cortical(MIC) may help find the osteoporosis.

• Journal of Digital Convergence
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• v.12 no.12
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• pp.441-447
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• 2014

The purpose of this study was to explore differences of spinal stabilization muscle strength between groups classified by BMI for industrial workers. Fifty subjects participated in this study were divided to obesity group(BMI over $25kg/m^2$) and non obesity group(BMI under $25kg/m^2$). Independent t-test was applied for analysis. The results showed the following. There were significant differences in $0^{\circ}$ Forward on sagittal plane, in both $90^{\circ}$ Left, $90^{\circ}$ Right on coronal plane, in $45^{\circ}$ Left Tilt, $45^{\circ}$ Right Tilt on diagonal plane between groups. Last, There were significant differences in an amount of soft lean muscle and an amount of skeletal muscle between groups. These results shows that spinal stabilization muscle strength program for the obese should be considered in sagittal plane, coronal plane, and diagonal plane.

• Journal of the Korean Society of Clothing and Textiles
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• v.16 no.2
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• pp.211-225
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• 1992

The purposes of this study were 1) to estimate the brand loyalty related to clothing items,2) to investigate the differences between the brand loyal group and the brand disloyal group in 4 determinant variables (product involvement, information source, purchase-related and demo- graphic variables) of brand loyalty, 3) to find out important determinant variables which explain the brand loyalty on clothing items, and 4) to identify product attributes that lead to brand loyalty on clothing items. Four clothing items selected (ortho study were underwear, jean / skirt, T-shirt / sweater, and formal dress / suits. The questionnaire was administered to 529 adult women living in Seoul, and the methods used to analyze the data were Frequency, T-Test, $x^{2}-test$, Factor Analysis and Multiple Discriminant Analysis. The results of this study were as follows: 1) Both behavior and attitude are needed for the measurement of brand loyalty in clothing. The hightes brand loyal item was formal dress / suits, followed by jean / skirt, T-shirt / sweater, underwear. 2) There were some significant differences between the brand loyal group and the brand disloyal group in 4 determinant variables of brand loyalty. 3) The important determinant variables of brand loyalty were perceived risk / brand differ-ence, purchase experience / self-confidence in purchase, and product symbolic / hedonic mean-ing, of which the most important varible was found to be perceived risk / brand difference. 4) The most important product attribute that lead to brand loyalty for underwear was comfort whereas for the other 3 clothing items, it was style. Quality was the second important productattributeforallclothingitems.

• Women's Health Nursing
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• v.4 no.3
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• pp.332-347
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• 1998

This study was performed for the purpose of analyzing the relationship of menopausal symptoms of midlife women between urban area and rural area. A total of 129 midlife women who have lived in seoul, Kyeung ki and Kangwon were selected conveniently and data were collected by structured questionnaire from May to June, 1998. The instruments were the menopausal symptoms scale developed by Neugarten, Ci Sung-Ai & Kim Hy-Eun. Data analysis was done by Chi-square test, ANOVA, t-test. The results of this study were summarized as follows ; 1. The mean score for the menopausal symptoms of midlife women was 2.12. Serious menopausal symptoms which could be found in this study were "joint pain and numbness of arm and leg"(2.63), "fatigue and powerlessness"(2.58), "nervousness"(2.44). Over 97.8% of women complained menopausal symptoms. 2. In the relationship between social demographic variables and menopausal symptoms of midlife women were significant difference in urban area and rural area(t=-4.569, P=.000), marriage status(F=4.809, P=.010), education(F=7.359, P=.000), married son and daughter(F=7.359, P=.000), mensturational status(F=5.993, P=.003), and satisfaction to husband(F=9.093, P=.000). 3. In the relationship of menopausal symptoms of midlife women between two groups were statistically significant differences(t=-4.569, P=.000). The mean score of menopausal symptoms of rural women(2.34) were higher than those of urban women(1.85). This study shows the possible implication for nursing intervention of midlife women's health to prevent and relieve menopausal symptoms.

• Journal of the Korean Applied Science and Technology
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• v.40 no.2
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• pp.189-198
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• 2023

This study aimed to identify the effects of nurses' interpersonal relationship ability on retention intention and turnover intention. The participants were 192 general duty nurses from a general hospital (95 with 36 months of experience or less, 97 with 37 months of experience or more) recruited using convenience sampling. Data were collected between February 15 and February 22, 2022. The data were analyzed by t-test, ANOVA, Pearson correlation coefficient, regression analysis, and more. The results demonstrated that turnover intention was higher among females. Also, a positive correlation between interpersonal relationship ability and retention intention was found to be significant among the nurses with at least 37 months of experience(r = .35, p < .001). The effect of interpersonal relationship ability on retention intention was found to be significant among the nurses with at least 37 months of experience(B = 0.71, t = 3.44, p < .001). However, the effect of interpersonal relationship ability on turnover intention was found to be nonsignificant. Based on these findings, this study concluded with the need for a strategy to strengthen interpersonal relation ability. during which the work experience should be considered, to promote nurses' retention intention.

• Imaging Science in Dentistry
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• v.54 no.2
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• pp.159-169
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• 2024

Purpose: The aim of this study was to evaluate the influence of different cone-beam computed tomography (CBCT) acquisition protocols on reducing the effective radiation dose while maintaining image quality. Materials and Methods: The effective dose emitted by a CBCT device was calculated using thermoluminescent dosimeters placed in a Rando Alderson phantom. Image quality was assessed by 3 experienced evaluators. The relationship between image quality and confidence was evaluated using the Fisher exact test, and the agreement among raters was assessed using the kappa test. Multiple linear regression analysis was performed to investigate whether the technical parameters could predict the effective dose. P-values<0.05 were considered to indicate statistical significance. Results: The optimized protocol (3 mA, 99 kVp, and 450 projection images) demonstrated good image quality and a lower effective dose for radiation-sensitive organs. Image quality and confidence had consistent values for all structures (P<0.05). Multiple linear regression analysis resulted in a statistically significant model. The milliamperage (b=0.504; t=3.406; P=0.027), kilovoltage peak (b=0.589; t=3.979; P=0.016) and number of projection images (b=0.557; t=3.762; P=0.020) were predictors of the effective dose. Conclusion: Optimized CBCT acquisition protocols can significantly reduce the effective radiation dose while maintaining acceptable image quality by adjusting the milliamperage and projection images.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.8
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• pp.5111-5120
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• 2015

In this paper, learn how to establish a proper lifestyle and health management through professional and systematic health education for children and young people, and laid the foundations for lifelong health, and to present the saeroeun paradigm complements the problems of school health education This study aimed to examine the effectiveness of the human body exploration camp program on elementary students in health promotion aspect. Survey was done pre-, post- and followup- tests for 61 participants in the camp. The evaluation consisted of 53 questionnaires multiple-choice written test on the changes of knowledge and attitude. Factor analysis and reliability analysis were used to SPSS WIN18.0 verify questionnaire's reliability and validity, and paired t-test were carried out in order to analyze knowledge and shift in attitude. In addition, regression analysis was carried out in order to the relation between the satisfaction, knowledge and attitude. By this study, we showed as follows. First, knowledge were increased post- than pre-test, follow up- than pre-test(p<0.01). Second, shift in attitude changed positively post- than pre-test(p<0.01), follow up- than pre-test(p<0.05). Third, satisfaction was closely related to shift in attitude(p<0.01). Therefore, it suggested that the implement of human body exploration camp for elementary students could be an alternative strategy in health education.