• Journal of The Korean Society of Agricultural Engineers
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• v.63 no.3
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• pp.35-45
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• 2021

Digestate or slurry produced from anaerobic digestion is mostly applied to crop lands for its disposal and recovering nutrients. However, minimizing nitrogen losses following field application of the digestate is important for maximizing the plant's nitrogen uptake and reducing environmental concerns. This study was conducted to assess the effects of three different biogas digestate application techniques (sawdust mixed with digestate (SSD), the hole application method (HA), and digestate injected in the soil (SD)) on nitrate leaching potential in the soil. A pot laboratory experiment was conducted at room temperature of 25 ± 2 ℃ for 107 days. The experimental results showed that sawdust application method turned out to be appropriate for quick immobilization of surplus N in the form of microbial biomass N, reflecting its lower total nitrogen and NH₄-N contents and low pH. The NH₄-N and total nitrogen fate in the soil fertilized with manure showed no statistically significant (p > 0.05) differences between the different methods applied during the incubation time under room temperature. In contrast, NO₃-N concentration indicates significant reduction in sawdust treatment (p < 0.05) compared to the control and other application methods. However, the soil sawdust mixed with digestate was more effective than the other methods, because of the cumulative labile carbon contents of the amendment, which implies soil net N immobilization.

• Communications for Statistical Applications and Methods
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• v.22 no.6
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• pp.625-637
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• 2015

We develop a Bayesian clustering procedure based on a Dirichlet process prior with cluster specific random effects. Gibbs sampling of a normal mixture of linear mixed regressions with a Dirichlet process was implemented to calculate posterior probabilities when the number of clusters was unknown. Our approach (unlike its counterparts) provides simultaneous partitioning and parameter estimation with the computation of the classification probabilities. A Monte Carlo study of curve estimation results showed that the model was useful for function estimation. We find that the proposed Dirichlet process mixture model with cluster specific random effects detects clusters sensitively by combining vague edges into different clusters. Examples are given to show how these models perform on real data.

• IE interfaces
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• v.15 no.2
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• pp.189-198
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• 2002

Simulated Annealing(SA) approach has been successfully applied to the combinatorial optimization problems with NP-hard complexity. To apply an SA algorithm to specific problems, generic parameters as well as problem-specific parameters must be determined. To overcome the embedded nature of SA, long computational time, some studies suggested the parameter design methods of determining SA related parameters. In this study, we propose a new parameter design approach based on robust design method. To show the effectiveness of the proposed method, the extensive computation experiments are conducted on the mixed-model sequencing problems.

• The Korean Journal of Applied Statistics
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• v.22 no.1
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• pp.153-161
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• 2009

We consider a logistic model with random effects as the superpopulation for estimating the small area pro-portions. The best linear unbiased predictor under linear mired model is popular in small area estimation. We use this type of estimator under logistic mixed motel for the small area proportions, on which the estimation of mean squared error is also discussed. Two kinds of estimation methods, the parametric bootstrap and the linear approximation will be compared through a Monte Carlo study in the respects of the normality assumption on the random effects distribution and also the magnitude of sample sizes on the approximation.

• Rapid Communication in Photoscience
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• v.5 no.1
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• pp.8-10
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• 2016

The potential curves of OH bonds of liquid water are inhomogeneous because of a variety of interactions with other molecules and this leads to a wide distribution of vibrational frequency which hampers our understanding of the structure and dynamics of water molecules. Mixed quantum/classical (QM/CM) calculation methods are powerful theoretical techniques to help us analyze experimental data of various vibrational spectroscopies to study such inhomogeneous systems. In a type of those approaches, the interaction energy between OH bonds and other molecules is approximately represented by the interaction between the charges located at the appropriate interaction sites of water molecules. For this purpose, we re-calculated the values of charges by comparing the approximate interaction energies with quantum chemical interaction energies. We determined a set of charges at the TIP4P charge sites which better represents the quantum mechanical potential curve of OH bonds of liquid water.

• Korean Journal of Clinical Laboratory Science
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• v.45 no.2
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• pp.60-65
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• 2013

Data from repeated measurements are accomplished through repeatedly processing the same subject under different conditions and different points of view. The power of testing enhances the choice of pertinent analysis methods that agrees with the characteristics of data concerned and the situation involved. Along with the clinical example, this paper compares the analysis of the variance on ex-post tests, gain score analysis, analysis by mixed design and analysis of covariance employable for repeating measure. Comparing the analysis of variance on ex post test, and gain score analysis on correlations, leads to the fact that the latter enhances the power of the test and diminishes the variance of error terms. The concluded probability, identified that the gain score analysis and the mixed design on interaction between "between subjects factor" and "within subjects factor", are identical. The analysis of covariance, demonstrated better power of the test and smaller error terms than the gain score analysis. Research on four analysis method found that the analysis of covariance is the most appropriate in clinical data than two repeated test with high correlation and ex ante affects ex post.

• The Korean Journal of Applied Statistics
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• v.17 no.1
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• pp.1-12
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• 2004

In this paper, we consider choosing the appropriate covariance structure for analyzing repeated measures data with three repeat factors from a study of blood pressure data, which is collected from the local residents of Yangpyeong, Gyeonggi-do (2001) and fitted linear mixed models to find the significant covariates on outcome variable(Blood Pressure)

• Journal of Agricultural Extension & Community Development
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• v.30 no.4
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• pp.171-186
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• 2023

This study aims to explore comprehensively the effects of a flower craft activity program focused on perceived stress, depression, and self-esteem of adult with mixed methods. The main results of this study are as follows. In the mixed analysis results, perceived stress was reduced by immersing oneself in completing one's own work through flower craft activities, as distracting thoughts in the head disappeared. In the case of depression, depression decreased in the relationship between group members who worked together to complete their own work through flower craft activities. In the case of self-esteem, it was analyzed that flower craft activities had the effect of increasing self-esteem through the satisfaction of the need for life and self-esteem. In future study, this suggests that the healing program applied based on this can be comprehensively reviewed, modified, and supplemented to reorganize it into a more effective flower craft activity program.

• Journal of Korean Public Health Nursing
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• v.34 no.3
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• pp.391-404
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• 2020

Purpose: This study investigates the disaster preparedness behaviors of people residing in disaster areas and the factors affecting such behaviors, by examining the application of a Health Belief Model. Methods: A mixed-method approach was used for this study. Local residents were surveyed in Gyeongju and Pohang, which had experienced earthquakes one to two years earlier. Quantitative data (N=233) were collected through a questionnaire and analyzed using t-test, one-way ANOVA, Scheffe test and multiple regression. Qualitative data (N=11) were collected through focus group and individual interviews, and evaluated through content analysis. Results: Disaster preparedness behaviors scored 7.04 out of 18 points, and factors that significantly affected disaster preparedness included cut to action, marriage status, experience of education and training related to disaster, benefit-barriers factors of disaster preparedness behaviors, and gender. The focus group and individual interviews confirmed the contents corresponding to each variable of the disaster preparedness behaviors and heal belief model. Conclusion: The findings of this study indicate that in order to induce disaster preparedness behaviors as well as education and training opportunities related to disaster relief, we need to examine cue to action of disaster preparedness behaviors, benefits, and barriers for motivating interventions.

• Journal of Korean Public Health Nursing
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• v.36 no.3
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• pp.347-360
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• 2022

Purpose: The purpose of this study was to identify the risk perception, safety climate and preventive behaviors of COVID-19 infections, and to verify the factors influencing the adoption of preventive behaviors by health care workers. Methods: A mixed-method approach was used based on a survey carried out in a general hospital. Quantitative data (N=181) were collected through a questionnaire and analyzed using multiple regression. Qualitative data (N=8) were collected through individual interviews and analyzed through Colaizzi's phenomological research method. Results: The factors influencing adoption of preventive behaviors by health care workers were safety climate (β=.41, p<.001), education (β=-.20, p=.025), work unit (β=-.16, p=.032), and risk perception (β=.15, p=.020). The explanatory power was 28.3%, and they have shown that these health care workers felt 'the threat of a pandemic like a battlefield', experienced 'struggle with quarantine rules' and realized 'the reality of infection control and the reorganization for change'. Conclusion: The findings of this study indicate that to increase the adoption of infection control preventive behaviors by health care workers when faced with new infectious diseases in the future, it is necessary to establish organizational support and a safe climate. This study confirms the need for preemptive support and education.