• Journal of Korean Society of Transportation
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• v.19 no.6
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• pp.131-142
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• 2001

Previous OD matrix estimation methods from link traffic counts have focused on the formulation of mathematical model and its solution algorithm. Thereby those methods have assumed that true or real OD is similar to the target OD and paid little attention to the properties of the change of OD structure. Although it is general situation that each OD pair increases or decreases due to significant land use and to large time variation between target OD with real OD, those methods have set unrealistic assumptions that target OD increases or decreases uniformly and that the OD structure does not change. Therefore those methods have showed poor performance of OD estimation in general situation. To cope with the problem. this paper suggests a new concept of OD matrix structure and shows the shortcomings of previous method′s dependancy on target OD matrix. We divide "OD trips" into "OD scale" and "OD structure". Where OD scale is a quantitative magnitude of OD trips and "OD structure" is ordinal OD scale. This paper use the same solution algorithm developed by Baek et al. (2000) for analysing the OD structure. Results of numerical examples show that the performance of the method is better than that of previous methods, while the previous methods have better performance in estimation only when OD trips increase or decrease. In addition to, if OD structure does not change, the results show that the error of estimation is low relatively regardless of the large difference of trips between target OD and real OD. This paper also shows that the model performance on OD structure and on OD trips is low as the number of origins that OD structure is changed increase. From the results we suggest that the change of OD structure can be more important information than the difference between target OD and real OD in OD estimation steps.

• The Korean Journal of Pain
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• v.34 no.4
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• pp.417-426
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• 2021

Background: Non-cardiac chest pain (NCCP) is a common patient complaint imposing great costs on the healthcare system. It is associated with psychological factors such as depression. The aim of the present study is determining depression predictors in NCCP patients. Methods: The participants of this cross-sectional study were 361 NCCP patients. Patients filled out questionnaires concerning their sociodemographic, lifestyle, and clinical factors (severity of pain, type D personality, somatization, cardiac anxiety, fear of body sensations, and depression). Results: Based on multiple ordinal logistic regression, lack of physical activity (odds ratio [OR], 1.78; 95% confidence interval [CI], 1.09-2.87), sleep quality (OR, 2.98; 95% CI, 1.15-7.69), being a smoker (OR, 1.33; 95% CI, 2.41-4.03), present pain intensity (OR, 1.08; 95% CI, 1.05-1.11), type D personality (OR, 2.43; 95% CI, 1.47-4.03), and somatization (OR, 1.22; 95% CI, 1.15-1.3) were significant predictors of depression in NCCP patients. Additionally, multiple linear regression showed that being unmarried (β = 1.51, P = 0.008), lack of physical activity (β = 1.22, P = 0.015), sleep quality (β = 2.26, P = 0.022), present pain intensity (β = 0.07, P = 0.045), type D personality (β = 1.87, P < 0.001), somatization (β = 0.45, P < 0.001), and fear of bodily sensation (β = 0.04, P = 0.032) increased significantly depression scores in NCCP patients. Conclusions: Physicians should consider the predictors of depression in NCCP patients which can lead to receiving effective psychological consultations and reducing the costs and ineffectual referrals to medical centers.

• Journal of Preventive Medicine and Public Health
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• v.54 no.5
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• pp.317-329
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• 2021

Objectives: The aim of this study was to identify the association between cohabitation status and sleep quality in family members of people with dementia (PwDs). Methods: Data of 190 365 participants aged ≥19 years from the 2018 Korea Community Health Survey were analyzed. Participants were categorized according to their cohabitation status with PwDs. Multiple logistic regression and ordinal logistic regression analyses were performed to evaluate the relationship between the cohabitation status of PwDs' relatives and sleep quality measured using the Pittsburgh Sleep Quality Index (PSQI) and PSQI subscales. Results: Compared to participants without PwDs in their families, both cohabitation and non-cohabitation with PwDs were associated with poor sleep quality (cohabitation, male: odds ratio [OR],1.28; 95% confidence interval [CI], 1.08 to 1.52; female: OR, 1.40; 95% CI, 1.20 to 1.64; non-cohabitation, male: OR, 1.14; 95% CI, 1.05 to 1.24; female: OR, 1.23; 95% CI, 1.14 to 1.33). In a subgroup analysis, non-cohabiting family members showed the highest odds of experiencing poor sleep quality when the PwD lived alone (male: OR, 1.48; 95% CI, 1.14 to 1.91; female: OR, 1.58; 95% CI, 1.24 to 2.01). Cohabiting male and female participants had higher odds of poor subjective sleep quality and use of sleeping medications than non-cohabiting male and female participants, respectively. Conclusions: The residence of PwDs and cohabitation status may contribute to poor sleep quality among PwDs' family members. The circumstances faced by cohabiting and non-cohabiting family members should be considered when evaluating sleep quality in family members of PwDs, and appropriate interventions may be needed to improve sleep quality in both cohabiting and non-cohabiting family members.

• 재활복지
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• v.18 no.4
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• pp.145-164
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• 2014

The purpose of the study is to examine the relationships of parents' satisfaction towards their children's school education and the demographic variables associated with decision-making on post high school academic completion of parents of the students with disabilities. The Korean Education Longitudinal Study data, which contained the responses of 162 parents of high school students with mild disabilities who enrolled in regular high schools, was used for the study. For data analysis, descriptive statistics, ordinal logistic regression analysis, and chi-square test were used. As a result, provision of college entrance related information/consultation, improvement of academic performance level, collaboration/ communication between the teachers and parents, and overall school education were significantly related to parents' decision-making on their children's post high school academic completion. Also, mothers' educational level showed significant difference in parents' decision-making on their children's post high school academic completion.

• Research in Community and Public Health Nursing
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• v.29 no.4
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• pp.440-449
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• 2018

Purpose: The purpose of this study is to identify the dietary habits of Korean adolescents and to investigate their effects on sleep duration. Methods: This study is a secondary analysis drawn from the 2016 Korean Youth Risk Behavior Web-Based Survey (N=65,528). ANCOVA was used to determine the relationship between dietary habits and sleep duration. Ordinal logistic regression was used to find out the effects of dietary habits on sleep duration adjusted for general characteristics and behavioral characteristics. Results: The group that consumed no breakfast (AOR=0.89, p<.001) had less sufficient sleep duration than those who had breakfast 7 times per week. The group that had drunk no milk (AOR=0.88, p<.001) had less sufficient sleep duration than those who enjoyed it 5 times per week. On the contrary, the groups that had no soda drinks (AOR=1.18, p=.015), caffeine drinks (AOR=1.77, p<.001), and sweet drinks (AOR=1.25, p<.001) were more likely to have sufficient sleep duration than the groups that consumed those beverages 5 times per week. Conclusion: It is important to educate adolescents about healthy eating habits including drinks and optimal sufficient sleep duration through a multidisciplinary approach.

• Journal of The Korean Society of Clinical Toxicology
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• v.19 no.1
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• pp.17-23
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• 2021

Purpose: Alcohol ingestion enhances impulsivity and aggression, and has been proven to have a close relationship with suicide. This study investigates whether alcohol co-ingestion affects the Poisoning Severity Score (PSS) grade in patients with intentional poisoning. Methods: We conducted a retrospective analysis of intentional poisoning patients who visited the emergency department (ED) from January 1 to December 31, 2020. Patients were divided into non-drunken and drunken groups. We collected the data based on the medical records of the patients and serum ethanol level results recorded during initial blood tests at the ED. To grade the PSS, the highest score was assessed through clinical signs and test results during the hospital stay. A comparative analysis was conducted between the two groups. Results: A total of 277 patients were included in the study. 163 (58.8%) were in the non-drunken group, and 114 (41.2%) were in the drunken group. The PSS grade showed a significant difference between the two groups (p=0.002). While grade 1 (mild) was observed more in the non-drunken group, grade 2 (moderate) and grade 3 (severe) were seen more in the drunken group. In an ordinal logistic regression analysis, alcohol co-ingestion (adjusted odds ratio [aOR] 2.557, 95% confidence interval [CI] 1.554-4.208, p<0.001) was considered to be a risk factor for a higher PSS grade. There was no significant correlation between the serum ethanol level and the PSS grade. (p=0.568) Conclusion: Intentional poisoning patients with alcohol co-ingestion had a higher PSS. Hence close observation and aggressive treatment in the ED is warranted in such cases.

• Communications for Statistical Applications and Methods
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• v.29 no.4
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• pp.421-439
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• 2022

Phase I dose-finding trials are essential in drug development. By finding the maximum tolerated dose (MTD) of a new drug or treatment, a Phase I trial establishes the recommended doses for later-phase testing. The primary toxicity endpoint of interest is often a binary variable, which describes an event of a patient who experiences dose-limiting toxicity. However, there is a growing interest in dose-finding studies regarding non-binary outcomes, defined by either the weighted sum of rates of various toxicity grades or a continuous outcome. Although several novel methods have been proposed in the literature, accessible software is still lacking to implement these methods. This study introduces a newly developed R package, UnifiedDoseFinding, which implements three phase I dose-finding methods with non-binary outcomes (Quasi- and Robust Quasi-CRM designs by Yuan et al. (2007) and Pan et al. (2014), gBOIN design by Mu et al. (2019), and by a method by Ivanova and Kim (2009)). For each of the methods, UnifiedDoseFinding provides corresponding functions that begin with next that determines the dose for the next cohort of patients, select, which selects the MTD defined by the non-binary toxicity endpoint when the trial is completed, and get oc, which obtains the operating characteristics. Three real examples are provided to help practitioners use these methods. The R package UnifiedDoseFinding, which is accessible in R CRAN, provides a user-friendly tool to facilitate the implementation of innovative dose-finding studies with nonbinary outcomes.

• The Journal of the Convergence on Culture Technology
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• v.8 no.2
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• pp.291-298
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• 2022

This study is a descriptive study to investigate the association between current smoking, high-risk alcohol drinking and depressive symptoms among female college students. The participants were 515 female college students, and data collection was conducted through online and mobile surveys from September 2020 to August 2021. Multivariable ordinal logistic regression analysis was performed to investigate the association between current smoking, high-risk drinking and depressive symptoms, and as a result, current smoking was significantly associated with depressive symptoms (OR= 2.524, 95% CI=1.051-6.061). Therefore, in order to improve the depressive symptoms of female college students, adequate support such as reducing the smoking rate through active smoking cessation education and preparing various on-campus programs should be provided.

• Journal of dental hygiene science
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• v.22 no.3
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• pp.171-179
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• 2022

Background: In this study, we investigated the changes and factors that affect daily health behaviors due to COVID-19 among adolescents. We intend to provide basic data so that a systematic and comprehensive health education program that includes physical and oral health can be made. Methods: This study was a secondary data analysis of the from the 2019 and 2020 Korea Youth Risk Behavior Web-based Survey. A final sample of 112,251 participants was anlayzed using chi-square test, and ordinal logistic regression. Results: In the case of tooth brushing, the frequency of 'never' increased in most general characteristics compared to before COVID-19. In the case of handwashing, it was found that handwashing behavior increased (increased) after COVID-19 compared to before COVID-19. As a result of confirming the factors affecting tooth brushing behavior before and after COVID-19, it was found that girls brushed teeth 2.2 times more regularly after lunch than boys. As a result of adjusting all other factors, regular tooth brushing behavior after COVID-19 was reduced by 0.79 times compared to before COVID-19. Conclusion: It is judged that it is necessary to operate a comprehensive health management program in the school so that the most basic tooth brushing for oral health and handwashing for health can become a habit. In addition, by confirming the impact of the COVID-19 pandemic on handwashing and tooth brushing behavior through this study, it is expected to be used in the development of policy data such as raising awareness of brushing and improving behaviors applicable in the current and upcoming new pandemic situations.

• Nutrition Research and Practice
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• v.17 no.1
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• pp.103-121
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• 2023

BACKGROUND/OBJECTIVES: The coronavirus disease 2019 (COVID-19) pandemic has affected the entire world population in many ways. This study aimed to analyze the patterns of changes in eating, food purchasing and preparation, physical activity, and subjective health after COVID-19 outbreak by various sociodemographic factors and to understand the factors associated with changes in subjective health. SUBJECTS/METHODS: A cross-sectional survey using a representative sample from Seoul was used for the analysis. The data collection was conducted from September to October 2020. A total of 3,833 citizens aged more than 18 years old participated in the Seoul Food Survey. Descriptive statistics and generalized ordinal logistic regression models were used to understand the changes in health behaviors, health indicators, and subjective general health by various socioeconomic status. RESULTS: It was shown that the changes in household income, food expenditure, food consumption and physical activities differed significantly by age, education, occupation, income, weight, and food security status. Low-income and food-insecure households were affected more severely by the pandemic. Older age, household food insecurity, income reduction, increased home cooking and frequency of having instant foods, decreased physical activity and weight gain were significant factors explaining worse perceived health during the COVID-19 pandemic. CONCLUSIONS: The results suggest that focusing on older populations and low-income families with food insecurity should be prioritized during infectious disease outbreaks. In addition, the role of physical activities and instant food consumption in explaining perceived health should be investigated further in this prolonged battle with the pandemic situation.