• Journal of Korean Society on Water Environment
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• v.37 no.2
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• pp.114-127
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• 2021

Water pollution in the lower reaches of the Namhan River is getting worse due to drought and a decrease in water quantity due to climatic changes and hence is affecting the water quality of Paldang Lake. Accordingly, we have used a water quality index (WQI) and statistical analysis in this study to identify the characteristics of the water quality in the lower reaches of the Namhan River, the main causes of water pollution, and tributaries that need priority management. Typically, 10 items (WT, pH, EC, DO, BOD, COD, SS, T-N, T-P, and TOC) were used as the water quality factors for the statistical analysis, and the matrix of data was set as 324 × 10·1. The correlation analysis demonstrated a strong correlation between Chemical Oxygen Demand (COD) and T-P with a high statistical significance (r=0.700, p<0.01). Furthermore, the result of principal component analysis (PCA) revealed that the main factors affecting the change in water quality were T-P and organic substances introduced into the water by rainfall. Based on the Mann-Kendall test, a statistically significant increase in pH was observed in SH-1, DL, SH-2, CM, and BH, along with an increase in WQI in SH-2 and SM. BH was identified as a tributary that needs priority management in the lower reaches of the Namhan River, with a "Somewhat poor" (IV) grade in T-P, "Fair" grade in WQI, and "Marginal" grade in summer.

• Journal of Periodontal and Implant Science
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• v.48 no.4
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• pp.251-260
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• 2018

Purpose: The aim of this retrospective cross-sectional study was to evaluate whether salivary findings of active matrix-metalloproteinase 8 (aMMP-8) chairside (point of care; POC) tests were associated with periodontal risk assessment parameters in patients receiving supportive periodontal therapy (SPT). Methods: A total of 125 patients receiving regular SPT were included, and their records were examined. The following inclusion criteria were used: a diagnosis of chronic periodontitis, at least 1 non-surgical periodontal treatment (scaling and root planning) with following regular SPT (minimum once a year), at least 6 remaining teeth, and clinical and aMMP-8 findings that were obtained at the same appointment. In addition to anamnestic factors (e.g., smoking and diabetes), oral hygiene indices (modified sulcus bleeding index [mSBI] and approximal plaque index), periodontal probing depth simultaneously with bleeding on probing, and dental findings (number of decayed, missing, and filled teeth) were recorded. Salivary aMMP-8 levels were tested using a commercial POC test system (Periomarker, Hager & Werken, Duisburg, Germany). Statistical analysis was performed using the t-test, Mann-Whitney U test, Fisher's exact test, and ${\chi}^2$ test, as appropriate (P<0.05). Results: Only the mSBI was significantly associated with positive salivary aMMP-8 findings (aMMP-8 positive: $27.8%{\pm}20.9%$ vs. aMMP-8 negative: $18.0%{\pm}14.5%$; P=0.017). No significant associations were found between aMMP-8 and smoking, diabetes, periodontal parameters, or parameters related to the maintenance interval (P>0.05). Conclusions: Salivary aMMP-8 chairside findings were not associated with common parameters used for periodontal risk assessment in patients receiving SPT. The diagnostic benefit of POC salivary aMMP-8 testing in risk assessment and maintenance interval adjustment during SPT remains unclear.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.8
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• pp.619-624
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• 2013

To predict the probabilistic service life, statistical factors should be included to consider the uncertainty of parameters. Generally the probabilistic analysis is one of the common methods to account the uncertainty of parameters on the structural failure. In order to apply probabilistic analysis on the deterministic life analysis, it would be necessary to introduce Probability of Failure(PoF) and conduct risk assessment. In this work, we have studied probabilistic risk assessment of aircraft structures by using PoF approach. To achieve this goal, the Bayesian method was utilized to model PoF estimation since this method is known as the proper method to express the uncertainty of parameters. A series of proof tests were also conducted in order to verify the result of PoF estimation. The results from this efforts showed that the PoF estimation model can calculate quantitatively the value of PoF. Furthermore effectiveness of risk assessment approach for the aircraft structures was also demonstrated.

• Fire Science and Engineering
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• v.30 no.6
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• pp.130-136
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• 2016

A university needs to analyze and improve its curricula with the perspective of the consumer to develop a syllabus for the training of industry-demand customized human resources. Accordingly, this paper surveyed the demand of fire-related industry workers to evaluate the major fitness of the curriculum of fire risk prediction and assessment and carried out descriptive statistical analysis, factor analysis, cluster analysis, and one-way ANOVA based on the results. According to the analysis, fire-related industry workers reported that the curriculum of fire risk prediction and assessment is suitable for majors. In addition, they were greatly aware of the necessity of basic major and common major subjects among subjects of fire risk prediction and assessment. The results of this analysis will provide the basic data to improve the curriculum continuously in the future.

• Korean Journal of Adult Nursing
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• v.28 no.1
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• pp.95-105
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• 2016

Purpose: This study was conducted to test whether Health Communication Assessment Tool (HCAT) developed by Campbell et al. in 2013 can be applied to assess Korean nursing students' communication skills in simulation education. Methods: The content validity of the Korean version of HCAT (K-HCAT) was evaluated through expert's assessment and a principal component analysis was conducted for testing construct validity. The convergent validity was tested by measuring relationship between the K-HCAT and those of existing communication assessment tool for standardized patient instruction. The evaluation was done by surveying 154 senior students from four different nursing colleges. Results: The K-HCAT was condensed into 15 items from the original 22 HCAT items. Four factors were extracted from the principal component analysis; factor loadings ranged from .50 to .83; cumulative explained variance was 62.65%. Four factors were entitled as 'relationship building', 'empowering', 'empathy/response', and 'education/feedback'. Cronbach's ${\alpha}$ for sub-dimensions ranged from .73 to .84. An evaluation of convergent validity showed that the scores of the K-HCAT were moderately correlated with those of an assessment tool for standardized patient instruction. Conclusion: The K-HCAT can be used as an effective tool for assessing nursing students' communication skills in various kinds of simulation educations Further research is needed to test the consistency of the K-HCAT.

• Journal of the Korean Society of Physical Medicine
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• v.12 no.2
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• pp.129-136
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• 2017

PURPOSE: The purpose of this study was to compare the gait of elderly patients with and without dementia to investigate the possibility of an ambulation assessment test as a diagnostic tool for dementia. METHODS: A total of 96 subjects were included with 60 participants without dementia (control group) and 36 patients with dementia (dementia group). To compare the walking ability of the two groups, a 4-m walking test (4MWT) and Groningen Meander Walking Test (GMWT) were conducted. The GMWT is graded by amount of time in seconds and by number of oversteps outside the track. Mann-Whitney U test was used to compare the gait between the groups and the area under the curve (AUC) with Received Operating Characteristic (ROC) curve was analyzed. Statistical significance was considered at a p<.05, with a 95% confidence interval. RESULTS: There were statistically significant differences (p<.05) between the dementia group and the control group for the 4MWT, GMWTSEC, and GMWTSTEP scores. The AUC was .95 for 4MWT, .92 for GMWTSEC, and .96 for GMWTSTEP with the 95% confidence interval. The cut-off values of the ROC curve were 1.03m/s for 4MWT, 10.8 second for GMWTSEC, and 3.75 steps for GMSTEP. CONCLUSION: In our study, we investigated the utility of ambulatory assessment tools to predict dementia. The results of this study suggest that the 4MWT and the GMWT used in this study are appropriate assessment tools for dementia prediction.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.1710-1715
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• 2010

Service life of water pipes buried in the underground is considerably affected from various factors such as environmental characteristics, pipe characteristics, operation and maintenance, etc. Therefore it is difficult to determine their service life as uniformly the same value assigned by related laws and ordinances. As a result, the service life should be determined by the technical judgement based on the assessment for the condition of water pipes. In this study, It was established that the methodology could predict present and future failure risk, and plan short and long-term strategies for replacement/rehabilitation through the assessment for the physical deterioration and economical values of buried water pipe. The methodology was applied for the verification and reliability to several sites selected in multi-regional transmission pipelines. The proposed method could helps to support reasonable and economical decision of rehabilitation/replacement in the present and future. To improve conventional assessment method of aged water pipes, affecting factors are simplified based on the statistical analysis results from the measured data in the field and the physical deterioration mechanism for better reliability. Also, the guide-line is developed to carry out the reasonal rehabilitation planning through water pipe condition assessment.

• Journal of People, Plants, and Environment
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• v.23 no.4
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• pp.433-443
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• 2020

Background and objective: The boom in urban agriculture has also resulted in the creation of many school gardens. With the increase in various hands-on education programs, people are interested in assessing the value of school gardens. This study was conducted to derive indicators for service value assessement of educational farming experience using school gardens. Methods: Through literature review, we selected assessment items and sub-factors. The indicators for evaluating the effectiveness of school gardens are classified using the Delphi method that involve a focus group experts. In order to increase the reliability and validity of the selected and classified items, an exploratory factor analysis was conducted. In addition, the relative importance and priority of each factor in each field were assessed using the analytic hierarchy process (AHP). Results: We classified the indicators into 4 criteria and come up with 13 items and 33 sub-factors in educational value, health value, economic value, and ecological and environmental value. Most of the items for the 4 value criteria derived were significant for assessing the value of agricultural experience services with content validity ratio (CVR) higher than 0.59 and reliability higher than .6 . In the value criteria, the experts rated educational value as the most important, followed by health value, ecological and environmental value, and economic value. In the assessment items, the most important was improvement of social functions. In the sub-factors, the most important was strengthening of ties (friendly interactions). Conclusion: Among the derived indicators assessing the value of school gardens, 4 criteria, 12 evaluation items and 29 sub-factors showed significance. The schematic index would be useful for the assessment.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.60 no.3
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• pp.244-257
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• 2024

Considering the negative impact of IUU fishing on fishery resources and fishery management, a revised approach for estimating risks of the ecosystem-based fisheries assessment (EBFA) of Zhang et al. (2011) was developed that incorporates three components of the IUU (illegal, unreported and unregulated) fishing as penalties. In this study, we introduced ways to develop indicators of IUU fishing suitable for the Korean fishery and apply them to ecosystem-based resource assessment. The indicator for the illegal fishing component was set as the fishing without licenses or permits, and that for the unreported fishing component was set as unreported fishing activities. Indicators for the unregulated fishing component were set as fishing operated by illegal fishing gear, illegal fish capture, fishing operations in prohibited fishing area, and fishing with restrict permits. IUU fishing significantly impacts the stock of target species. Therefore, in this study, the influence of IUU fishing is included in the Species Risk Index (SRI) at the species level, and weights are assigned based on the ratio of the stock, as $SRI={{\sum\limits_j}{\lambda}_j{\cdot}ORI/{\sum\limits_j}{\lambda}_j}+P_f(B_i/B)$. The revised ecosystem-based fisheries assessment method, which considers the impact of IUU fishing, was applied to major fisheries on the south coast of Korea. It is necessary to reduce the non-reporting rate through the expansion of the TAC system and improve the accuracy of statistical compilation. To this end, the electronic fishing reporting system, which is being implemented on all vessels in Korean distant water fishing vessels, should be introduced to the coastal and offshore fisheries as well.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2182-2191
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• 2011

Postmortem evaluation through the dictionary and the lack of points for the wrong strategy to respond to the avoid the prediction is important. However, the prevailing system of ex post facto assessment of postmortem simply does not have statistical figures to be provided only for the conditions. Thus, in this study, rail business is mainly evaluation procedures and evaluation of the verification system of ex post facto evaluation as to the issue, do not improve.