• Journal of the Korean Society of Groundwater Environment
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• v.4 no.3
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• pp.144-152
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• 1997

In this study the experiment on water retention cure was conducted by using a volumetric pressure plate extractor for two different soils (SUS and KUS). When the volumetric pressure plate extractor is used, the volume of water removed from the soil sample at each increasing pressure step can be accurately measured and retained. When pressure values are subsequently reduced, the volume of water that returns to the soil can then also be accurately measured. The hysteresis effect of water retention curve was considered in the experiment. Parameters of water retention function were estimated by fitting experimental data with three proposed equations. Results of estimation showed that parameters of Gardner, Brooks-Corey and van Genuchten equations were found to be associated with air-entry value and width of size distribution. Consequently van Genuchten equation was proved to be best fined through the measured data points.

• The korean journal of orthodontics
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• v.50 no.5
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• pp.314-323
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• 2020

Objective: To identify the available evidence on the effects of rapid maxillary expansion (RME) with three-dimensional imaging and provide meta-analytic data from studies assessing the outcomes using computed tomography. Methods: Eleven electronic databases were searched, and prospective case series were selected. Two authors screened all titles and abstracts and assessed full texts of the remaining articles. Seventeen case series were included in the quantitative synthesis. Seven outcomes were investigated: nasal cavity width, maxillary basal bone width, alveolar buccal crest width, alveolar palatal crest width, inter-molar crown width, inter-molar root apex width, and buccopalatal molar inclination. The outcomes were investigated at two-time points: post-expansion (2-6 weeks) and post-retention (4-8 months). Mean differences and 95% confidence intervals were used to summarize and combine the data. Results: All the investigated outcomes showed significant differences post-expansion (maxillary basal bone width, +2.46 mm; nasal cavity width, +1.95 mm; alveolar buccal crest width, +3.90 mm; alveolar palatal crest width, +3.09 mm; intermolar crown width, +5.69 mm; inter-molar root apex width, +2.85 mm; and dental tipping, +3.75°) and post-retention (maxillary basal bone width, +2.21 mm; nasal cavity width, +1.55 mm; alveolar buccal crest width, +3.57 mm; alveolar palatal crest width, +3.32 mm; inter-molar crown width, +5.43 mm; inter-molar root apex width, +4.75 mm; and dental tipping, 2.22°) compared to pre-expansion. Conclusions: After RME, skeletal expansion of the nasomaxillary complex was greater in most caudal structures. Maxillary basal bone showed 10% post-retention relapse. During retention period, uprighting of maxillary molars occurred.

• Food Science of Animal Resources
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• v.30 no.6
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• pp.1024-1030
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• 2010

The focus of the study was to maximize the output data for Korean cuisine. This study evaluated the nutritional retention factor for different cuts of Korean beef (Hanwoo beef) subjected to various cooking methods. Five cuts (short rib, sirloin, chuck roll, tenderloin, and fore shank) of Korean Hanwoo beef were prepared and used in this experiment. Two different cooking methods (dry-heat cooking and moisture-heat cooking) were applied to each cut. The sodium contents of dry-heat cooked short rib (86.44), sirloin (76.81), tenderloin (86.65), and fore shank (85.89) decreased. Potassium contents of dryheat cooked sirloin (94.99), chuck roll (89.19), and fore shank (92.66) decreased. Calcium contents of dry-heat cooked sirloin (61.49), chuck roll (73.97), and fore shank (91.46) decreased. Iron contents of dry-heat cooked chuck roll (79.71), and tenderloin (90.79) decreased. Phosphorus contents of dry-heat cooked sirloin (87.87), and tenderloin (99.88) decreased. Mineral contents of all cuts cooked by moisture-heat decreased. Finally, the nutritional retention factor represents output data of each cooking method with yield % of each item.

• Journal of Korean society of Dental Hygiene
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• v.21 no.2
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• pp.159-170
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• 2021

Objectives: This study aimed to investigate factors for retention intention among long-term employed dental hygienists and to provide basic data for improving the long-term service (working) environment. Methods: A total of 202 dental hygienists with more than five years' work experience at dental hospitals and clinics located in Seoul, Gwangju, and Jeonnam Province, South Korea, were surveyed. The data were analyzed for each factor using exploratory factor analysis, and differences according to the general characteristics of the participants were analyzed using an independent sample t-test, one-way ANOVA and a hierarchical multiple regression analysis. Results: At the current workplace, a better working environment, and higher job satisfaction were associated with higher retention intention. However, lower professionalism in dental hygiene as a subdomain of the professional self-concept domain was associated with higher retention intention. Conclusions: To increase retention intention among dental hygienists, it is necessary to improve the working environment in which dental hygienists can perform professional roles and seek ways to establish their identity as professionals in dental healthcare settings.

• Journal of Korean Academy of Nursing
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• v.51 no.3
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• pp.320-333
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• 2021

Purpose: The study was conducted to explore the experiences of job retention among working people with mental illness. Methods: The participants were members with mental illness at the S Community Mental Health Center in Gyeonggi Province and who had been working for more than six months. The data were collected through in-depth interviews with 11 participants between June 27 and August 20, 2018. The data were analyzed through Corbin and Strauss's grounded theory method. Results: The core category was struggling to take root in the community as a productive member. The core phenomenon was the desire to be a productive person, and the causal condition was the willingness to change for a purposeful life. The action and interaction strategies included maintaining regular living patterns, maintaining medication, developing one's tips for self-management, and self-approval. The intervening conditions were difficulties in forming social relationships, presence of symptoms, social resources, and acceptance of one's mental illness. The consequences were restoration of family relationships, healthy pleasure through work, social inclusion, development of self-worth, and transition to an independent person. Conclusion: Working people with mental illness are struggling to take root in the community as a productive member. This study suggests that a holistic understanding of the job retention experience among people with mental illness is required. The findings will provide the basis for developing interventions that can improve job retention among working people with mental illness.

• Water for future
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• v.28 no.4
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• pp.215-222
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• 1995

The water retention function which has the hysteresis phenomena is required to analyze the Richards equation which is a governing equation of the unsaturated flow, and its hysteresis phenomena has influence upon the characteristics of the unsaturated flow. The accuracy of the published hysteresis models is compared by using experimental data of the water retention function. The apparatus to experiment the hysteresis phenomena on the soil is developed, and experimental data for the main wetting process and the main drying process of the water retention function are obtained. The parameters of the van Genuchten equation are calibrated by using experimentally obtained data. As a result of the comparison of the selected hysteresis models which simulate the main drying curve from the main wetting curve, the Model I-1(Mualem) overestimates and the Model II-1(Mualem) underestimates but the Model III-2(Park and Sonu) similarly estimates the experimental data of the main drying curve.

• Women's Health Nursing
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• v.25 no.3
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• pp.329-344
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• 2019

Purpose: This study aimed to identify utilization of the work-family support policy (WFSP) and factors affecting retention intention among Korean female military officers. Methods: This cross-sectional survey recruited 103 married female officers from the Korean Army, Navy, and Air force with preschool-aged children through convenience and snowball sampling. Via online surveys from June to November, 2018, the participants self-reported retention intention, work-family conflict, job satisfaction, and utilization of the WFSP. The data were analyzed using descriptive statistics, independent t-tests, one-way analysis of variance, Pearson's correlation coefficient, and multiple linear regression. Results: Retention intention ($22.29{\pm}5.98$) was reported at the mid-level, lower than scores reported in the literature for female workers. Work-family conflict ($32.51{\pm}5.29$) and job satisfaction ($63.10{\pm}7.45$) were above the midpoint levels. Use of maternity leave (100.0%) and parental leave (92.2%) was high, especially compared to the rates of child-care day off (20.4%) and parenting time (20.4%). 'Noticeable increases in childcare services within the army' (22.8%) was reported as the supportive measure needed the most by female military officers. Job satisfaction (${\beta}=.43$, $p{\leq}.001$), the use of parenting time (${\beta}=-0.29$, p=.002), living type (${\beta}=-.18$, p=.043), and service type (${\beta}=-.16$, p=.035) significantly influenced retention intention. Conclusions: The findings highlight the priority areas of importance within the WFSP and suggest that a family-friendly culture can improve female officers' retention intention. Accordingly, policy changes at the Ministry of National Defense improving the system to enhance a family-friendly culture in the military is expected to strengthen the retention intention of female officers and contribute to excellence in the military workforce.

• Nuclear Engineering and Technology
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• v.49 no.7
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• pp.1405-1413
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• 2017

To investigate the heat loads imposed on a reactor vessel through the natural convection of core melts in severe accidents, mass transfer experiments were performed based on the heat transfer/mass transfer analogy, using two- (2-D) and three-dimensional (3-D) facilities of various heights. The modified Rayleigh numbers ranged from $10^{12}$ to $10^{15}$, with a fixed Prandtl number of 2,014. The measured Nusselt numbers showed a trend similar to those of existing studies, but the absolute values showed discrepancies owing to the high Prandtl number of this system. The measured angle-dependent Nusselt numbers were analyzed for 2-D and 3-D geometries, and a multiplier was developed that enables the extrapolation of 2-D data into 3-D data. The definition of $Ra^{\prime}_H$ was specified for 2-D geometries, so that results could be extrapolated for 3-D geometries; also, heat transfer correlations were developed.

• Korean Management Science Review
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• v.21 no.3
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• pp.85-99
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• 2004

The retention of customer is an increasingly pressing issue in today's competitive environment. The proposes of this paper is a personalized defection detection and the procedure of prevention based on economic analysis of customer defection possibility, and behaviour state transition cost. This procedure is based on the observation that potential defectors have a tendency to take a couple of months or weeks to gradually change their behaviour before their eventual withdrawal. In this procedure, the SOM(Self-Organizing Map) is used to determine the possible states of customer behaviour from past behaviour data, and to prevent the defection of potential defectors, the proposed procedure recommends the desirable behaviour state for the next period based on the analysis of transition cost. and likelihood of defection. The case study has been conducted for a Korean on-line game provider to evaluate of this procedure.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.10
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• pp.595-600
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• 2016

In this paper, the oxide currents of thin silicon oxides is investigated. The oxide currents associated with the on time of applied voltage were used to measure the distribution of voltage stress induced traps in thin silicon oxide films. The stress induced leakage currents were due to the charging and discharging of traps generated by stress voltage in the silicon oxides. The stress induced leakage current will affect data retention in memory devices. The oxide current for the thickness dependence of stress current and stress induced leakage currents has been measured in oxides with thicknesses between $109{\AA}$, $190{\AA}$, $387{\AA}$, and $818{\AA}$ which have the gate area $10^{-3}cm^2$. The oxide currents will affect data retention and the stress current, stress induced leakage current is used to estimate to fundamental limitations on oxide thicknesses.