• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.7
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• pp.1004-1010
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• 2021

Ship-floating object accidents can lead not only to a delay in ship's operations, but also to large scale casualties. Hence, preventive measures are required to avoid them. This study analyzed the spatiotemporal aspects of such collisions based on the data on ship-floating object accidents in sea areas in the last five years, including the collisions in South Korea's territorial seas and exclusive economic zones. We also provide basic data for related research fields. To understand the distribution of the relative density of accidents involving floating objects, the sea area under analysis was visualized as a grid and a two-dimensional histogram was generated. A multinomial logistic regression model was used to analyze the effect of variables such as time of day and season on the collisions. The spatial analysis revealed that the collision density was highest for the areas extending from Geoje Island to Tongyeong, including Jinhae Bay, and that it was high near Jeongok Port in the West Sea and the northern part of Jeju Island. The temporal analysis revealed that the collisions occurred most frequently during the day (71.4%) and in autumn. Furthermore, the likelihood of collision with floating objects was much higher for professional fishing vessels, leisure vessels, and recreational fishing vessels than for cargo vessels during the day and in autumn. The results of this analysis can be used as primary data for the arrangement of Coast Guard vessels, rigid enforcement of regulations, removal of floating objects, and preparation of countermeasures involving preliminary removal of floating objects to prevent accidents by time and season.

• Journal of Sasang Constitutional Medicine
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• v.32 no.1
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• pp.30-38
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• 2020

Objectives The purpose of this study is to reduce the question items in Korea Sasang Constitutional Diagnostic Questionnaire (KS-15) and to assess the validity. Methods The subjects of this study were 1,553 people who had information on body shape, personality, and symptoms among the data established at the Korean Medicine Data Center. Among them, 155 people were separated into a test group to assess the validity, and the remaining 1,398 were used as training groups for model development. The reduction question items were finally confirmed through discussion by two experts. The model development went through Multinomial Logistic Regression. Results & Conclusions The Percent Correctly Predicted (PCP) in the test group was 60.00% (58.49% in men and 60.78% in women). The PCP of each constitution was 72.6% in Taeeumin, 53.3% in Soeumin, and 50% in Soyangin. The accuracy rate of KS-10 seems to be reasonable considering the ease of use of reduced time required.

• Human Ecology Research
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• v.51 no.3
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• pp.321-331
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• 2013

The purpose of this study is to develop the scale to measure family health and to analyze the data collected by the survey in order to develop the educational program for healthy family. The sample of this study is taken by 522 housewives who are living in Seoul and are over the age of 40. The data are analyzed according to frequency, percentages, t-test, Pearson's correlation analysis, and Multinomial logistic Regression analysis. The results of this study are as follows. First, the scale measuring family health is developed through interviews with the respondents, preliminary survey, and comments reviewed from specialists. The responses to the scale are significantly different depending on whether they answered their family is healthy or not. Second, minimum family performances for family health are related to the category of social involvement of the family. Third, the types of healthy family are grouped by the responses related to the current state and the status of family health. The number of the type of the worst state-the worst status of family health is the largest, followed by the number of the type of the best state-the best status of family health. Fourth, the important and significant variables that affected the types of family health are psychological variables rather than personal and household-related variables of the respondents.

• Journal of Construction Engineering and Project Management
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• v.8 no.2
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• pp.17-33
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• 2018

This study investigates the stability of professionals' cost variability factor-rankings across different levels of cost-variability and response scenarios. Descriptive statistics are used to examine the stability of factor-ranking for 20 cost variability factors and a Multinomial Logistic (MNL) regression model was implemented to examine the stability of cost variability factors across three cost variability levels. The finding on the descriptive statistics indicated that professionals' factors-rankings are stable only for external factors. The MNL regression results on factor-stability suggested that 8 out of the 20 evaluated factors were unstable determinant of lower cost variability levels. These factors are "risk associated with the project", "personal bias and poor professionalism of the estimators", "limited time available to complete the project", "lack of skills and experience by estimator" "geographical location of projects", "incomplete & rush designs for estimate", "unforeseen or unexpected site constraints", "high class bidders for the contractors". Similarly lack of experience and large size projects were observed to be unstable as well. These observations suggest that professionals' view on pre-tender cost variability factor-ranking yields unstable factor rankings hence should not be relied upon as the only mechanisms to mitigate cost related risks in construction projects.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.50 no.3
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• pp.284-291
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• 2014

Finely-striate buccinum Buccinum striatissimum, a species of whelks, is caught mainly by pot in the eastern coastal waters of Korea. In order to determine the size selectivity of pot for the species, comparative fishing experiments were conducted near Yeongil Bay from June to September in 2003 using the dome-shaped pots with different five mesh sizes (17.1, 24.8, 35.3, 39.8, and 48.3 mm). The parameters of logistic equation were estimated by the SELECT (Share Each Length's Catch Total) method based on a multinomial distribution. The model with the estimated split parameter was found to fit the catch data best. The master selection curve was estimated to be s (R)=exp (13.044R-16.438)/[1 + exp (13.044R-16.438)], where R is the ratio of shell height to mesh size. The relative shell height of 50% retention was 1.260, and the selection range was 0.168. Enlargement in mesh size of the pot allows more small-sized whelks to escape.

• Journal of Korean society of Dental Hygiene
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• v.18 no.2
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• pp.205-215
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• 2018

Objectives: The purpose of the study is to investigate the relationship between the number of remaining teeth and bone health status among adults over 65 years old. Methods: The study subjects were 1,843 adults over 65 years old drawn from the Korea National Health and Nutrition Examination Survey (KNHANES) in 2008-2010. Oral health status included the number of remaining teeth, and prosthetic appliance status. Bone health statuses were assessed using dual-energy X-ray absorptiometry (DEXA). Bone health statuses were classified into normal (T-score ${\geq}-1.0$), osteopenia (-2.5 < T-score < -1.0), and osteoporosis (T-score ${\leq}-2.5$). Complex samples chi-square test was used to estimate the relationship between the number of remaining teeth and bone health status, and related factors included in the model were analyzed with the complex samples logistic regression analysis. Results: Using the multinomial logistic regression analytic method, the elderly having 20 or more remaining teeth and those having less than 20 remaining teeth with prosthesis were compared. The latter group had 1.89 times higher rate of being diagnosed as having osteoporosis. Conclusions: This study suggests that oral health is an important factor for geriatric osteoporosis. Therefore, in order to prevent fractures due to osteoporosis and osteoporosis in old age, it is necessary to be aware of the relationship between oral health and osteoporosis, and oral health should be considered when preparing preventive management strategies.

• Nutrition Research and Practice
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• v.12 no.3
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• pp.233-242
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• 2018

BACKGROUND/OBJECTIVES: The effects of fish consumption by subjects with prediabetes on the metabolic risk factors were examined based on the data from the $6^{th}$ Korea National Health and Nutrition Examination Surveys in 2015. SUBJECTS/METHODS: A total of 1,520 subjects who agreed to participate in a blood test and dietary intake survey were divided into a prediabetes group and normal blood glucose group, and the level of the subjects' fish consumption was divided into ${\leq}17.0g/day$, 18.0-93.0 g/day, and ${\geq}94g/day$. The correlation between the level of fish intake and the metabolic risk factors was evaluated by multinomial logistic regression analysis. RESULTS: A significant difference in the gender distribution was observed in the prediabetes group, which is a group with a high risk of non-communicable diseases, according to the fish intake, and there were significant differences in the total energy intake, protein intake, n-3 fatty acids intake, and the intakes of sodium and micro-nutrients according to the intake group (P < 0.05). In addition, the blood total cholesterol (TC) decreased 0.422 fold in model 1 (unadjusted) [95% confidence interval (CI): 0.211-0.845] and 0.422 fold in model 2 (adjusted for sex) (95% CI: 0.210-0.846) in those with a fish intake of 18.0-93.0 g/day (P < 0.05) compared to those with a fish intake of ${\leq}17.0g/day$. The blood TC decreased 0.555 fold (95% CI: 0.311-0.989) in model 1 and 0.549 fold (95% CI: 0.302-0.997) in model 2 in those with a fish intake of ${\geq}94g/day$ compared to those with a fish intake of ${\leq}17.0g/day$ (P < 0.05). CONCLUSION: Subjects with prediabetes or the metabolic risk factors can maintain their blood low density lipoprotein cholesterol (LDL-C) and blood TC concentrations at the optimal level by consuming fish (18.0-93.0 g/day).

• Korean Journal of Social Welfare Studies
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• v.48 no.2
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• pp.303-329
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• 2017

This study aimed to explore the trajectories of computer game use of school age children and to identify the related predictors. The data for this study used Korean Children and Youth Panel data covering from the second year to the sixth year of elementary school. A total of 1,959 participants were analyzed. Latent class growth model was employed to explore the trajectories of computer game use and multinomial logistic regression was conducted to identify the significant predictors. Main results indicated that three types of trajectories were identified: low game using group, high initial using-fluctuating group, and high increasing game using group. Each group was found to be associated deferentially with sex, aggression, attention deficit, main caregiver's education, siblings, parent absence after-school, neglecting, family income, family trip, school grades, and peer relationship. Based on these findings, this study emphasized the importance of predictive intervention for the game user among early school age children and suggested useful practical strategies.

• Imaging Science in Dentistry
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• v.54 no.1
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• pp.71-80
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• 2024

Purpose: This study aimed to evaluate age-stratified radiographic features in temporomandibular joint osteoarthritis using cone-beam computed tomography. Materials and Methods: In total, 210 joints from 183 patients(144 females, 39 males, ranging from 12 to 88 years old with a mean age of 44.75±19.97 years) diagnosed with temporomandibular joint osteoarthritis were stratified by age. Mandibular condyle position and bony changes (flattening, erosion, osteophytes, subchondral sclerosis, and subchondral pseudocysts in both the condyle and articular eminence, thickening of the glenoid fossa, joint space narrowing, and joint loose bodies) were evaluated through cone-beam computed tomography. After adjusting for sex, the association between age groups and radiographic findings was analyzed using both a multiple regression model and a multinomial logistic regression model(α=0.05). Results: The prevalence of joint space narrowing and protruded condyle position in the glenoid fossa significantly increased with age (P<0.05). The risks of bony changes, including osteophytes and subchondral pseudocysts in the condyle; flattening, erosion, osteophyte, and subchondral sclerosis in the articular eminence; joint loose bodies; and thickening of the glenoid fossa, also significantly rose with increasing age (P<0.05). The number of radiographic findings increased with age; in particular, the increase was more pronounced in the temporal bone than in the mandibular condyle (P<0.05). Conclusion: Increasing age was associated with a higher frequency and greater diversity of bony changes in the temporal bone, as well as a protruded condyle position in the glenoid fossa, resulting in noticeable joint space narrowing in temporomandibular joint osteoarthritis.

• Journal of the Korean Association of Geographic Information Studies
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• v.23 no.4
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• pp.42-51
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• 2020

This study was performed to support the 6th forest basic planning by Korea Forest Service as predicting the change of forestland area by the transition of land use type in the future over 35 years in South Korea. It is very important to analyze upcoming forestland area change for future forest planning because forestland plays a basic role to predict forest resources change for afforestation, production and management in the future. Therefore, the transitional interaction between land use types in future of South Korea was predicted in this study using econometrical models based on past trend data of land use type and related variables. The econometrical model based on maximum discounted profits theory for land use type determination was used to estimate total quantitative change by forestland, agricultural land and urban area at national scale using explanatory variables such as forestry value added, agricultural income and population during over 46 years. In result, it was analyzed that forestland area would decrease continuously at approximately 29,000 ha by 2027 while urban area increases in South Korea. However, it was predicted that the forestland area would be started to increase gradually at 170,000 ha by 2050 because urban area was reduced according to population decrement from 2032 in South Korea. We could find out that the increment of forestland would be attributed to social problems such as urban hollowing and localities extinction phenomenon by steep decrement of population from 2032. The decrement and increment of forestland by unbalanced population immigration to major cities and migration to localities might cause many social and economic problems against national sustainable development, so that future strategies and policies for forestland should be established considering such future change trends of land use type for balanced development and reasonable forestland use and conservation.