• Journal of Korean Society of Water and Wastewater
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• v.19 no.2
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• pp.144-148
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• 2005

The industrial development of large scale deep bed filters has been a very important step in the process of drinking water production and more recently in the tertiary treatment of wastewater. The target of deep bed filtration is the retention is the retention of small particles generally smaller than 30 microns at relatively small concentration, generally less than 30 mg/l from natural water (surface water or aquifers) or secondary treated wastewater. The relation between the retention efficiency and the characteristics of the particles has been extensively studied experimentally and through different models of retention. During the last years the development of new technologies (fiber filter, membrane modules) lead to more intensive processes compared to conventional sand filtration. Fiber filters can combine intensification with a decrease in specific energy needed however they cannot be operated under gravity like sand filters. Membrane filters (UF or MF) are much more intensive and efficient than sand filters. The specific energy needed is not so high (about $0.1Kwh/M^3$) but is higher than sand or fiber filter. A Life Cycle Analysis (LCA) has to be made for a complete comparison between these technologies taking in account that the efficiency of particle retention obtained by membrane filters is unique.

• Nuclear Engineering and Technology
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• v.54 no.7
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• pp.2702-2713
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• 2022

A steam generator tube rupture accompanying a core damage may cause the fission product to be released to environment bypassing the containment. In such an accident, the steam generator is the major path of the radioactive aerosol release. AEOLUS facility, the scaled-down model of Korean type steam generator, was built to examine the aerosol removal in the steam generator during the steam generator tube rupture accident. Integral and separate effect tests were performed with the facility for the dry and flooded conditions, and the decontamination factors were presented for different tube configurations and submergences. The dry test results were compared with the existing test results and with the analyses to investigate the aerosol retention physics by the tube bundle, with respect to the particle size and the bundle geometry. In the flooded tests, the effect of submergence were shown and the retention in the jet injection region were presented with respect to the Stokes number. The test results are planned to be used to constitute the aerosol retention model, specifically applicable for the analysis of the steam generator tube rupture accident in Korean nuclear power plants to evaluate realistic fission product behavior.

• Journal of The Korean Society of Agricultural Engineers
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• v.55 no.4
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• pp.1-11
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• 2013

Unsaturated hydraulic conductivity function is one of key parameters to solve the flow phenomena in problems of landslide. Prediction models for hydraulic conductivity function related to soil-water retention curve equations in many geotechnical applications have been still used instead of direct measurement of the hydraulic conductivity function since prediction models from soil-water retention curve equations are attractive for their fast and easy use and low cost. However, many researchers found that prediction models for the hydraulic conductivity function can not predict the hydraulic conductivity exactly in comparison with experimental outputs. This research introduced an inverse analysis to evaluate the hydraulic conductivity function corresponding to experimental output from the flow pump system. Optimisation process was carried out to obtain the hydraulic conductivity function. This research showed that the inverse analysis with flow pump system was suitable to assess the hydraulic conductivity in unsaturated soil, and the prediction models for the hydraulic conductivity were led to the significant discrepancy from actual experimental outputs.

• Journal of Korean Academy of Nursing Administration
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• v.16 no.3
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• pp.229-239
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• 2010

Purpose: This study aimed to investigate the impact of nursing professionalism on the nursing performance and retention intention among psychiatric mental health nurses. Methods: As a descriptive correlational study, this study sampled 206 psychiatric mental health nurses in six hospitals in Seoul and Gyeonggi area through convenience sampling. Data were collected from March 2 to 31, 2009 using a self-report questionnaire. The collected data were analyzed using SPSS WIN 16.0. Results: In the subscales of professionalism, the 'Sense of calling' had the highest mean score while the 'Professional organization' had the lowest mean score. A significant positive correlation was observed in nursing professionalism, nursing performance and retention intention. According to an analysis on the impact of each subscale of nursing professionalism on nursing performance and retention intention, the 'Sense of calling' and 'Autonomy' were the most significant predictor variable. Conclusion: The results confirmed that the improvement of psychiatric mental health nurses' professionalism increases their nursing performance and retention intention and the 'Sense of calling' and 'Autonomy' are critical prediction factors. It is necessary to come up with a strategy which strengthens nursing professionalism in order to improve psychiatric mental health nurses' performance and retention intention.

• The Journal of the Korea Contents Association
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• v.10 no.7
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• pp.344-354
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• 2010

The primary purpose of this study is to examine the effects of customer satisfaction and switching barrier on customer retention and intention of WOM in insurance services. Based on relevant literature reviews, this study posits three switching barrier characteristics, that is, switching costs, attractiveness of alternatives and interpersonal relationship as key determinants of customer retention and intention of WOM. And then we structured a research model and hypotheses about relationship between these variables. A total 230 usable survey responses of life insurance service users have been employed in the analysis. The major findings from the data analyses are as follows. Firstly, customer satisfaction had a positive influence upon customer retention and intention of WOM. Secondly, two switching barrier characteristics of switching costs and interpersonal relationship had a positive influence upon customer retention. Lastly, customer retention had very significantly related to intention of WOM in insurance services. From this study, we expect to suggest practical and managerial implications to insurance service providers.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2009.04a
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• pp.23-28
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• 2009

The purpose of this study was to improve not only wet-end performances but also paper characteristics by the modification of various factors like molecular design and ionic characteristics of polyacrylamides First of all physical characteristics were observed after modify molecular design of the cationic polyacrylamides to linear, branched and cross-linked. In addition it was found analysis method to confirm branch degree of cationic polyacrylamides to combine ionic titration characteristics and spectroscopic behavior, After application of these structure modified polyacrylamides to the multiple retention systems with inorganic microparticles, it was found adjusting of branch degree of polyacrylamides was very important to optimize wet-end improvement. Second, After polymerization of amphoteric polyacrylamide to have both of cationic and anionic functional group in the polymer, we observed not only physical characteristics but also wet-end improvement to apply recycled pulp and found that the improvement of solution stability to prevent hydrolysis and increase of ash retention dramatically to compare traditional cationic polyacrylamide retention aid, Finally, After polymerization of anionic polyacrylamide, we observed not only wet-end improvement but also paper characteristics to apply preflocculation of PCC and it was found the improvements of flocculation efficiency, retention, ash retention, optical properties of the paper and bursting strength to compare traditional preflocculant of cationic polyacrylamide.

• Journal of Digital Convergence
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• v.16 no.10
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• pp.261-270
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• 2018

The purpose of this study is to investigate the effect of work-family conflict and social support on retention intention in married female nurses. Participants were nurses working in 5 general hospitals in C city and data were collected from September 1 to 15, 2017. Data were analyzed by t-test, one-way ANOVA, Pearson's correlation, multiple regression analysis using SPSS Win 23.0. Factors influencing retention intention were identified as following; time-based conflict, more than one child, charge nurse, support of a co-workers, managers' support, with 37.3% explanatory power. This study shows that time-based conflict has negative effect on retention intention, while support of co-workers and managers have positive effect. This result may be useful in developing new strategies for enhancing retention intention. Further research is needed to identify other factors affecting the retention intention of married female nurses.

• Journal of Convergence for Information Technology
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• v.9 no.12
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• pp.236-243
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• 2019

This purpose of this study was indentify the effect of the workplace bullying, resilience and retention intention on dental hygienists' retention intention and conducted in order to be applied to basic data for enhancing dental hygienists' retention intention. The participants in the study were 202. Data were analyzed using SPSS 19.0, t-tst, ANOVA, regression analysis. The dental hygienists' retention intention showed a high outcome in case of the higher employment satisfaction (p<.001), in the lower workplace bullying(p=.011) and in the higher resilience(p<.001). Conclusively, this study indicate a need to develop program the efficiently promote resilience and to plan improving organizational culture to increase retention intention in dental hygienists.

• Women's Health Nursing
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• v.28 no.1
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• pp.18-26
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• 2022

Purpose: This study investigated whether parenting stress, work-family conflict, resilience affect retention intent in Korean nurses returning to work after parental leave. Methods: The participants in this study were 111 nurses recruited from 10 hospitals in Korea, who were working after formal parental leave from their hospitals. Collected data were analyzed using descriptive statistics, the t-test, analysis of variance, the Mann-Whitney U-test, Pearson correlation coefficients, and hierarchical regression. Results: Retention intention (33.80±7.78), parenting stress (101.70±17.57), and resilience (85.02±12.75) were at greater than moderate levels and a midpoint level of work-family conflict (29.63±7.00) was noted in this sample of mostly women nurses in their 30s. The factors affecting retention intent were parental leave duration, the number of times that participants had taken parental leave, health condition, work-family conflict, and resilience. The total explanatory power of these variables was 36.7%. Retention intent had a negative correlation with parenting stress and work-family conflict. Conversely, retention intent was positively correlated with resilience. Conclusion: This study supports the need for flexible adjustment of returning nurses' working hours and family-friendly policies to promote balance between work and family. It is also necessary to develop and apply measures that boost resilience and support health improvement for nurses returning to work.As nurses are often assigned to new areas of work upon return, training programs to aid their adjustment may also be helpful.

• Horticultural Science & Technology
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• v.28 no.4
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• pp.656-663
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• 2010

In order to improve the consumer acceptance of fragrant yellow hybrids of $Phalaenopsis$ ($Phal.$), crosses between yellow hybrid varieties were made and the obtained hybrids were investigated for horticultural characteristics as well as difference in fragrance patterns. Cross combination of $Phal.$ Brother lawrence and $Phal.$ Brother saragold yielded good seedling population of 500 plants. Segregation was noticed in color density, spot and stripe patterns on yellow color base of petal and also in fragrance. Six lines with multi-branch on flower stalk and strong fragrance flower were finally selected. Volatile fragrance components were compared among $Phal.$ Brother lawrence, $Phal.$ Brother saragold and their hybrids by GC/SAW electronic nose. In the derivative pattern of chromatogram and polar derivative pattern of fragrance, similar dominant peaks appeared on retention time 7-9 s and some hybrid lines had two strong peaks on retention time 20-25 s, respectively. Also in polar frequency pattern of fragrance obtained by $VaporPrint^{TM}$ image analysis among parent flowers and hybrids, an identical strong peak near 8 s of retention time was shown. This single fragrance component is considered a key element of fragrance in $Phal.$ Brother lawrence, $Phal.$ Brother saragold and their hybrids. This peak could be used as a marker for the breeding of fragrance in $Phalaenopsis$.