• Journal of Korean Society of Transportation
• /
• v.13 no.1
• /
• pp.167-183
• /
• 1995

The objective of study is to evaluate highway capaicty estimation alternative and to develop capacity from statistical distribution of observed traffic flow. Speed-Volume relation is analyzed from vehicle's headway distribution eliminating the long headway by confidence intervals 99%, 95%, 90%. Capacity estimate alternatives were evaluated from 95% , 90%, 85% level of cummulative distribution of observed hourly traffic flow adjusted to confidence intervals. The result of investigation revealed that maximum hourly rate of flow is 2, 130pcu at confidence interval of 995, 2, 233pcu at 95%, 2, 315pcu at 90% respectively. Compared to the capacity of 2, 200pcu per hour per lane used in HCM and KHCM(Korea Highway Capacity Manual), capa챠y appears to correspond to confidence interval of 95%. Using the traffic flow rate at confidence interval of 95% the maximum hourly flow rate is 2, 187pcu at 95% of cummulative volume distribution, 2, 153pcu at 90%, 2, 215pcu at 85%. The study suggests that raional capacity esimation alternative is to take the 95% of cummulative distribution of observed hourly traffic flow at 95% confidence headway interval eliminating 5% long headway.(i.e. 95-95 rule)

• Journal of muscle and joint health
• /
• v.29 no.1
• /
• pp.41-49
• /
• 2022

Purpose: The purpose of this study was to assess the influence of nurses staffing level on patient health outcomes in intensive care units (ICUs) in Korea. Methods: The study was retrospective in nature. Information on patients and their outcomes, as well as nurse cohort data, were obtained from Korea's National Health Insurance Service Database. The observation period was from January 1, 2008 to December 31, 2018, and data for 2,964,991 patients were analyzed. Independent variables included patient' age and sex and hospital type, intensivist, and nurses staffing level. Results: The mortality rate in ICUs was significantly higher at tertiary hospitals with a level 3~4 (HR, 1.21; 95% confidence interval, 1.19~1.22) or level 5~9 nurse staffing (HR, 1.31; 95% confidence interval, 1.27~1.34) compare to that of tertiary hospitals with a 1~2 level. 28-day mortality rate was also higher at general hospitals with a level 3~4 (HR, 1.13; 95% confidence interval, 1.12~1.14), level 5~6 (HR. 1.34; 95% confidence interval, 1.32~1.36), level 7~9 nurse staffing (HR, 1.38; 95% confidence interval, 1.38~1.42), using level 1~2 as reference. Conclusion: Nurses staffing level is a key determinant of healthcare-associated mortality in critically ICUs patients. Policies to achieve adequate nurse staffing levels are therefore required to enhance patient outcomes.

• International Journal of Internet, Broadcasting and Communication
• /
• v.16 no.1
• /
• pp.314-320
• /
• 2024

Objectives: This study aimed to identify the prevalence of falls in community-dwelling older adults and to identify associated factors using the 2019 Community Health Survey. Methods: The original data was from the 2019 Community Health Survey, and the study sample comprised 1,642 older adults aged 65 years and older in Jeju province. Data collection was conducted from August 16 to November 20, 2019, through an interview done by a trained investigator. Respondents were queried about demographic characteristics, riding bicycles, hospital treatment due to an accident or poisoning in the previous year, fall experiences in the past year, fear of falling, self-management status, and pain and discomfort. Multivariate logistic regression analysis was used to evaluate for associations between potential risk factors and falls. Results: The prevalence of falls in this community-dwelling older adults was 13.1%. Falls were associated with riding bicycles (odds ratio = 4.7; 95% confidence interval: 2.26-9.81), fear of falling (odds ratio = 0.3; 95% confidence interval: 0.24-0.49), hospital treatment due to an accident or poisoning in the previous year (odds ratio = 7.8; 95% confidence interval: 5.02-12.19), self-management status (odds ratio = 0.6; 95% confidence interval: 0.34-0.89), and pain and discomfort (odds ratio = 0.6; 95% confidence interval: 0.40-0.87). Conclusions: We found that the prevalence of approximately about 13% of older adults living in a community has experienced falls. Based on the results of the study, we provided primary data to develop the care management intervention program to prevent falls and avoid risk factors that cause falls in community-dwelling older adults.

• Pediatric Gastroenterology, Hepatology & Nutrition
• /
• v.11 no.2
• /
• pp.110-115
• /
• 2008

Purpose: Intussusceptions are one of the most common causes of intestinal obstruction in infants and young children. Although it is easily treated by non-operative reduction using barium, water or air, this treatment is very stressful for young patients and may cause bowel perforation, peritonitis and shock. In this study, we identified the risk factors associated with the failure of non-operative reduction, to identify a group of children that would benefit from the procedure and those who would not. Methods: We reviewed the medical records of patients with intussusception who were treated at the Korea University Medical Center Ansan hospital from March 1998 to July 2006. Three hundred fourteen children with intussusception were identified. Among them, non-operative reductions were performed in three hundred. Clinical and radiological variables were compared according to the failure or success of the non-operative reduction. Results: Non-operative reductions were successful in 243 (81%) and failed in 57 (19%). The group that had failed procedures had a younger age (12.3${\pm}$17.2 months vs. 18.0${\pm}$15.8 months, p=0.03), longer symptom duration before reduction (33.6${\pm}$29.0 hr vs. 21.5${\pm}$20.3 hr, p<0.01), more vomiting and lethargy (p<0.01), but less abdominal pain and irritability (p<0.01), compared with the group that had a successful procedure. Logistic regression analysis showed that the factors associated with the failure of non-operative reductions were a younger age, less than 6 months of age (odds ratio: 2.5, 95% confidence interval: 1.2~5.2, p=0.01), duration of symptoms, longer than 24 hrs before reduction (odds ratio: 2.1, 95% confidence interval: 1.2~4.2, p=0.03), bloody stool (odds ratio: 4.8, 95% confidence interval: 1.9~12.2, p<0.01), lethargy (odds ratio: 3.4, 95% confidence interval: 1.1~10.4, p=0.04), and abdominal pain or irritability (odds ratio: 0.2, 95% confidence interval: 0.1~0.4, p<0.01). Conclusion: For children with intussusception, an age younger than 6 months, and duration of symptoms more than 24 hrs before reduction, as well as the presence of bloody stools, lethargy and abdominal pain or irritability were variables associated with failure of a non-operative reduction. Knowledge of these variables should be considered in making clinical decisions for therapeutic interventions.

• Genomics & Informatics
• /
• v.18 no.3
• /
• pp.31.1-31.8
• /
• 2020

The coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has become a global pandemic. No specific therapeutic agents or vaccines for COVID-19 are available, though several antiviral drugs, are under investigation as treatment agents for COVID-19. The use of convalescent plasma transfusion that contain neutralizing antibodies for COVID-19 has become the major focus. This requires mass screening of populations for these antibodies. While several countries started reporting population based antibody rate, its simple point estimate may be misinterpreted without proper estimation of standard error and confidence intervals. In this paper, we review the importance of antibody studies and present the 95% confidence intervals COVID-19 antibody rate for the Korean population using two recently performed antibody tests in Korea. Due to the sparsity of data, the estimation of confidence interval is a big challenge. Thus, we consider several confidence intervals using Asymptotic, Exact and Bayesian estimation methods. In this article, we found that the Wald method gives the narrowest interval among all Asymptotic methods whereas mid p-value gives the narrowest among all Exact methods and Jeffrey's method gives the narrowest from Bayesian method. The most conservative 95% confidence interval estimation shows that as of 00:00 on September 15, 2020, at least 32,602 people were infected but not confirmed in Korea.

• Journal of Digital Convergence
• /
• v.14 no.7
• /
• pp.225-232
• /
• 2016

This paper aimed to study on the relevance of mental health and oral health. The subjects were recruited total 3,261 elderly of over 40 years old, using the Sixth Korea National Health and Nutrition Examination Survey(KNHANES). All the collected data were analyzed by chi-square test, t-test, and logistic regression using SPSS 23.0 version. Logistic regression was used to analyze the relationship of sleeping time or stress and the number of remaining teeth, and 95% confidence intervals were computed. Sleeping time odds ratio(OR) of the number of remaining teeth was 1.52 (95% confidence interval: 1.074-2.135) and Stress odds ratio(OR) was 2.39 (95% confidence interval: 1.855-3.090), but there is no statistically significant difference after adjusted age, gender and other variables.

• Journal of Korean society of Dental Hygiene
• /
• v.16 no.1
• /
• pp.19-25
• /
• 2016

Objectives: The purpose of the study is to investigate the relationship between the number of remaining teeth and depression in Korean adults. Methods: The subjects were the respondents of the Sixth Korea National Health and Nutrition Examination Survey(KNHANES). The questionnaire consisted of the general characteristics of the subjects, number of remaining teeth, and prevalence of depression. relationship of the prevalence of depression and the number of remaining teeth. The data were analyzed by chi-square test, t-test, and logistic regression using SPSS, and 95% confidence intervals were calculated. Results: There was a significant difference in number of remaining teeth and odds ratio(OR) was 1.940(95% confidence interval: 1.062-3.544). Statistically significant difference was not observed after adjusting for age and gender and OR was 1.515(95% confidence interval: 0.823-2.787). And Statistically significant difference was not observed after adjusting for age, gender and other variables. The OR was 1.399(95% confidence interval: 0.757-2.586). Conclusions: Depression in the adults was related to the number of remaining teeth. But there was no significant difference in the number of remaining teeth after adjusted for age, gender, and other factors.

• Environmental and Resource Economics Review
• /
• v.18 no.3
• /
• pp.431-455
• /
• 2009

This study estimates the WTP for the plan of solving deforestation due to limestone mining and calculates that damage cost using contingent valuation method. As the results of analysing a dichotomous choice CV data, the yearly mean WTP per household for the plan is 5,045 won(95% confidence interval : 3,729~6,360 won) in single bounded CV model and is 4,361 won(95% confidence interval : 3,710~5,012 won) in double bounded CV model. The damage cost of deforestation due to limestone mining can be estimated as 55.3% of WTP for the plan which is assigned to restoring the deforestation area to the original or similar alternative state. The average yearly deforestation cost of 1 ha due to limestone mining is reached 20.90 million won(95% confidence interval : 16.53~25.27 million won). And the asset value of that 1 ha damage is 160.02 million won(95% confidence interval : 126.56~193.49 million won). The fact is found that the damage cost of deforestation using replacement cost method is likely to be underestimated. The total damage cost of deforestation because of limestone mining in 3 cities (Donghae, Samcheok, Yeongwol) is 204.0 billion won(95% confidence interval : 161.4~246.7 billion won) which is composed of 26.5% for Donghae, 28.9% for Samcheok, and 44.6% for Yeongwol according to the damage size of deforestation due to limestone mining in 3 cities.

• Tuberculosis and Respiratory Diseases
• /
• v.48 no.6
• /
• pp.944-955
• /
• 2000

Background : In patients with chronic obstructive pulmonary disease(COPD), several factors have been associated with a poor prognosis. These include old age, low $FEV_1$ low diffusing capacity, high alveolar-arterial oxygen pressure difference, and finally cor pulmonale. This study was done to investigate if the ECG signs suggesting cor pulmonale were independent prognostic factors in patients with COPD. Method : We analyzed ECG, pulmonary function data and arterial blood gas values in 61 patients who were admitted through the emergency department with an acute exacerbation of COPD. The ECG signs reflecting cor pulmonale were right strial overloading(RAO), right bundle branch block, right ventricular hypertrophy and low-voltage QRS. The 61 patients were divided into 2 groups ; group I with no ECG signs(n=36) and group II with one or more ECG signs(n=25) suggesting cor, pulmonale. Results : Poor, prognostic factors by univariate analysis were low $FEV_1$, $FEV_1$ % pred., VC % pred., DLco, DLco % pred., $PaO_2$ and $SaO_2$ high $PaCO_2$ presence of ECG signs reflecting cor pulmonale, presence of mental status change, use of mechanical ventilator, and long term use of glucocorticoid. A multivariate analysis indicated that age(risk ratio=1.13, 95% confidence interval 1.05-1.23), DLco % pred. (risk ratio=0,97. 95% confidence interval 0.94-0.99), $PaO_2$ (risk ratio=0.95, 95% confidence interval 0.90-0.99) and RAO(risk ratio=5.27, 95% confidence interval 1.40-19.85) were independent prognostic factors of survival. There was a significant difference in survival between the patients with and without RAO(p=0.038). The survival rates at 1, 2, and 5 years were 94.5%. 81.4%, and 50.0% in patients without RAO and 82.4%, 70.6%, and 27.5% in patients with RAO, respectively. Conclusion : These results suggest that the presence of ECG signs reflecting cor pulmonale is a predictor of survival and that RAO of these ECG signs is a significant independent predictor of survival in patients with COPD.

• Journal of Gastric Cancer
• /
• v.13 no.3
• /
• pp.136-148
• /
• 2013

Purpose: To define the role of robotic gastrectomy for the treatment of gastric cancer, the present systematic review with meta-analysis was performed. Materials and Methods: A comprehensive search up to July 2012 was conducted on PubMed, EMBASE, and the Cochrane Library. All eligible studies comparing robotic gastrectomy versus laparoscopic gastrectomy or open gastrectomy were included. Results: Included in our meta-analysis were seven studies of 1,967 patients that compared robotic (n=404) with open (n=718) or laparoscopic (n=845) gastrectomy. In the complete analysis, a shorter hospital stay was noted with robotic gastrectomy than with open gastrectomy (weighted mean difference: -2.92, 95% confidence interval: -4.94 to -0.89, P=0.005). Additionally, there was a significant reduction in intraoperative blood loss with robotic gastrectomy compared with laparoscopic gastrectomy (weighted mean difference: -35.53, 95% confidence interval: -66.98 to -4.09, P=0.03). These advantages were at the price of a significantly prolonged operative time for both robotic gastrectomy versus laparoscopic gastrectomy (weighted mean difference: 63.70, 95% confidence interval: 44.22 to 83.17, P<0.00001) and robotic gastrectomy versus open gastrectomy (weighted mean difference: 95.83, 95% confidence interval: 54.48 to 137.18, P<0.00001). Analysis of the number of lymph nodes retrieved and overall complication rates revealed that these outcomes did not differ significantly between the groups. Conclusions: Robotic gastrectomy for gastric cancer reduces intraoperative blood loss and the postoperative hospital length of stay compared with laparoscopic gastrectomy and open gastrectomy at a cost of a longer operating time. Robotic gastrectomy also provides an oncologically adequate lymphadenectomy. Additional high-quality prospective studies are recommended to better evaluate both short and long-term outcomes.