• Fire Science and Engineering
• /
• v.24 no.6
• /
• pp.1-6
• /
• 2010

A smoldering ground fire can be a probable cause of reignition of surface fire when transmitted from Fermentation layer to Humus layer with temperature higher than that of ignition. Purpose of this paper is to identify experimental methodology on the potential risk of a smoldering ground fire, which is similar to the real surface fuel bed, and its combustion characteristics. The fuel model designed in this study is composed of 3 layers such as Litter layer, Fermentation layer and Humus layer and 8 Thermocouples are set through 3 layer at each boundary and in between to detect the temperature change and duration of smoldering and propagation velocity. As a result, it was observed that ignition conditions in the boundary between L layer and F layer determined transmission and non-transmisstion to F-H layer. In addition, range of critical humidity at which a smoldering ground fire was transmitted in a material layer was 33~44% and when temperature exceeds $350^{\circ}C$, likelihood of transmission of a smoldering ground fire was high. In the research, the experimental model for multi-layer smoldering ground fire is suggested and information about propagation of smoldering fire, possibility of reignition according to moisture content, propagation velocity and temperature change are obtained, Also, the built-up methods were established to help analyze basic characteristics of smoldering ground fire.

• Asian-Australasian Journal of Animal Sciences
• /
• v.22 no.4
• /
• pp.459-464
• /
• 2009

Data and pedigree information for Lori-Bakhtiari sheep used in this study were 6,239 records of lamb mortality from 246 sires and 1,721 dams, collected from 1989 through 2007 from a Lori-Bakhtiari flock at Shooli station in Shahrekord. The traits investigated were cumulative lamb mortality from birth up to 7 days, up to 14 days, up to 21 days, and up to 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 and 12 months of age. The models included fixed factors that had significant effects and random direct genetic, maternal genetic and maternal permanent environmental effects. Variance components were estimated using the restricted maximum likelihood procedure applying three animal models with and without maternal and common environmental effects. The overall mean of cumulative lamb mortality rate was 22.95% from birth to 1 year of age, while the overall mortality rate up to 3 and from 3 to 6 months of age was 6.14% and 12.76%, respectively. The mortality rate after 6 months of age declined as the lambs grew older. The age of dam had no important effect on lamb mortality. The type of birth was more important during the preweaning period than at later ages, and lamb mortality rate was higher in twins. The year of birth, month of birth and sex of lamb significantly (p${\leq}$0.01) affected the cumulative lamb mortality rate at all ages. The least square mean of mortality during the final one-third of the lambing period was higher than the first and middle onethird of the lambing period. Male lambs were found to be at a higher risk of mortality than females. Birth weight of the lamb had a highly significant (p${\leq}$0.01) effect on lamb mortality at all ages as a quadratic regression. Direct and maternal heritability estimates of lamb mortality ranged from 0.01 to 0.13 and 0.01 to 0.05, respectively. Direct heritability increased with age of lamb, while maternal effects (genetic and common environmental) were important in the preweaning period. These results indicate that lamb mortality can be reduced first through farm management practices and secondly by genetic selection. Both animal and maternal effects should be considered in breeding programmes for reducing lamb mortality at preweaning.

• Journal of Yeungnam Medical Science
• /
• v.17 no.1
• /
• pp.66-74
• /
• 2000

Background: During the follow up period after transarterial embolization(TAE), cases of pulmonary metastasis were more prevalent in TAE-treated patients than in TAE-untreated patients. Therefore, a study was conducted to evaluate whether TAE increases the incidence of pulmonary metastasis of hepatocellular carcinoma and to clarify the risk factors for pulmonary metastasis. Methods: From March 1991 to March 1995, 156 patients who had been diagnosed with hepatocellular carcinoma by serology, and radiographic and histologic methods at Yeungnam University hospital were involved in this study. We excluded 12 patients with lung metastasis on initial diagnosis and the others. The remaining 144 patients had been followed up for at least 5 months and, divided into four groups according to lung metastasis and trans-arterial embolization treatment, and evaluated for age, sex, child-pugh score, liver cirrhosis, and level of AFP. Results: Pulmonary metastasis was found in 18.0% (26/144), of which 92.3%(24/26) and 7.7%(2/26) of the patients with and without transarterial chemoembolization, respectively. Of the patients, 23.5% (24/102) with TAE had lung metastais during follow-up periods and 4.7% (2/42) without TAE had lung metastasis. There was more likelihood for lung metastasis after TAE. but there was no difference between two groups in age, sex, child-pugh class, the presence of liver cirrhosis, and AFP. Conclusions: The incidence of pulmonary metastasis of hepatocellular carcinoma after TAE was higher. Child-pugh class was the only related clinical preciptating factors for pulmonary metastasis in TAE in our study. Our results suggest that regular chest X-ray check-ups may be more frequently needed by patients who had TAE treatment for hepatocellular carcinoma.

• Korean Journal of Clinical Laboratory Science
• /
• v.50 no.2
• /
• pp.155-163
• /
• 2018

Bilirubin has an anti-inflammatory effect as an endogenous antioxidant and has been reported to be inversely correlated with hypertension, diabetes, metabolic syndrome, and insulin resistance. On the other hand, there is a lack of research evaluating the association between bilirubin and metabolic syndrome compared to liver-specific indicators. This study examined the association between the total bilirubin and metabolic syndrome prevalence in Korean adults who underwent health screening compared to ALT and GGT. This cross sectional study included 22,568 adult males and females aged 20 years or older who underwent a health examination at the General Hospital of Gyeonggi Province from March 2015 to February 2018. Metabolic syndrome was diagnosed based on the American Heart Association/National Heart, Lung, and Blood Institute (AHA/NHLBI) guidelines. In both genders, the metabolic syndrome diagnosed group had higher liver enzymes, and the total bilirubin and direct bilirubin were lower than those without the metabolic syndrome risk factors. The serum total bilirubin showed a weak inverse correlation with abdominal obesity (r=-0.066 vs r=-0.055) and triglyceride (r=-0.127 vs r=-0.136) in both males and females, which is weaker than ALT and GGT The data were statistically significant. In addition, total bilirubin as well as ALT and GGT in both men and women were not predictors of the likelihood of developing metabolic syndrome.

• Journal of Digital Convergence
• /
• v.12 no.10
• /
• pp.467-476
• /
• 2014

This study aims to determine the effects of mental health on obesity among Korean adolescents. The data in this study were obtained from the 2013 Korean Youth Health Risk Behavior Web-based Survey conducted in 70,354 adolescents aged twelve to eighteen (35,575 males and 34,779 females) from June 1 to 30, 2013. The variables included age, the economic status of household, academic achievement, health status, perceived happiness, perceived stress, satisfaction of sleeping, perceived depression, and suicidal ideation and the data were processed using t-test, chi square test, and logistic regression analysis. The general characteristics affecting obesity for both Korean male and female adolescents included age (p<0.001), the economic status of households (p<0.001), academic achievement (p<0.001), and health status (p<0.001); the variable of mental health affecting obesity was suicidal ideation among females (p<0.05). It is expected that female adolescents' experience of suicidal ideation can be used as information to predict the likelihood of obesity in managing an obesity program for adolescents and it is necessary to provide obesity education suitable for age and to include obesity guidance in consideration of gender and the economic status.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.5
• /
• pp.3139-3147
• /
• 2015

The aim of this study was to investigate the condition surrounding attempted suicide and related factors among middle and high school students in Korea. Methods : Data from 72,435 participants of 2013 Korea Youth Risk Behavior Web-based Based Survey were analyzed. Statistical analyses were conducted on weighted data using SPSS 21 software to account for the complex sampling designs. Results : Complex samples logistic regression analysis, school level, socioeconomic status, drinking alcohol, drug use, experience of school bullying were associated with an increased proportion of attempted suicide for boys and girls. Particularly, male students was associated with living type. Conclusion : The results of this study highlight the important of developing a program that focuses on enhancing suicidal prevention & respect life program with life skills program, to effectively reduce the likelihood of attempted suicide among adolescents in Korea.

• Korea journal of population studies
• /
• v.32 no.1
• /
• pp.25-50
• /
• 2009

Using the Korean labor and Income Panel Study, this study examines the impact of educational attainment on first marriage formation in Korea. In particular, this study examines whether higher education is associated primarily with delayed marriage or with a higher likelihood of never marrying. The results show that the trend toward later and less marriage is occurring at all levels of educational attainment in Korea. The data also indicated that educational attainment showed differential effects on the risk of first marriage formation for Korean men and women. For those born before 1970, both highly educated men and women delayed marriage but caught up by marrying at higher rates at later ages. However, for those born after 1970, highly educated women were increasingly more likely to show the trend toward later and less marriage, while highly educated men were more likely to delay marriage but caught up by marrying at higher rates at later ages. Overall the evidence in this study is consistent with the argument that gender divisions make it difficult for women to balance work and family in Korea.

• The Journal of the Korea Contents Association
• /
• v.17 no.5
• /
• pp.8-17
• /
• 2017

Using 1855 observations from 5 years-371 firms panel data during 2010 to 2014 in Chinese stock exchanges, this study examines the impact of managers' ownership on R & D expenditures. The empirical study finds that when firms are state-owned, managers' ownership have negative relation with the level of R & D expenses as well as the likelihood of executing R & D investment, implying that managers are less likely to invest in high risky projects due to managerial ownership's entrenchment effects to pursue private benefits rather than alignment of interest effect as shareholders. The empirical study also finds that when firms are private-owned, managerial ownership are inverse U shaped related to the level of R & D expenses, implying that managers are less likely to invest in high risky projects due to increasing risk aversion resulting from concentration of private wealth at its high level while managers are more likely to invest in high risky projects due to increasing incentives as shareholders at its low level. The results support that the effects of managerial ownership on R & D expenses may be different according to the ownership type of Chinese listed firms.

• 한국노년학
• /
• v.32 no.4
• /
• pp.993-1011
• /
• 2012

The purpose of this study is to investigate the factors associated with the incidence and the transition of disability among Korean older adults. Samples consist of 1,454(42.7%) men and 2,032(58.3%) women aged 65 and over who participated in the 1st and 2nd wave of the Korea Longitudinal Study of Aging: KLOSA. To estimate the level of disability, ADL and IADL disability indexes are used. As the results, major risk factors for ADL/IADL disability incidence include injury, vision problem, cognitive function, depression, health behavior, socioeconomic characteristics and age. Among the normal older adults, the odds ratio of having dementia symptoms at 2nd wave(2008) are 2.0 times greater for the older adults who have less cognitive function than those who don't have at 1st wave(2006). Among the older adults with chronic diseases, the odds ratio of having disability at 2nd wave are 1.8 times greater for the older persons who have depression than those who don't have at 1st wave. Secondly, concerning the predictors affecting the disability transition among the disabled older adults at 1st wave, the likelihood of remaining at the same level or deteriorating the level of IADL disability, as compared with improving the level, is associated with having less instrumental support or being older. These results indicate that it is necessary to prefer multilevel intervention in order not only to prevent the incidence of disability, but also to prolong the deterioration of disability in the older adults.

• Health Policy and Management
• /
• v.30 no.4
• /
• pp.493-504
• /
• 2020

Background: There have been many studies on the associations between body mass index (BMI) and cognitive function. However, no study has ever compared the associations across the methods of categorizing BMI. In this study, we aimed to fill the gap in the previous studies and examine whether the obesity paradox is valid in the risk of cognitive function. Methods: Of the 10,254 people aged 45 and older from the Korean Longitudinal Study of Ageing from 2006 to 2016, 8,970 people were finalized as the study population. The dependent variable was whether a person has a normal cognitive function or not, and the independent variables of interest were BMI categorized by the World Health Organization Western Pacific Regional Office (WHO-WPRO) method, the WHO method, and a 10-group method. Covariates included sociodemographic factors, health behavior factors, and health status factors. A generalized linear mixed model analysis with a logit link was used. Results: In the adjusted model with all covariates, first, in the case of BMI categories of the WHO-WPRO method, underweight (odds ratio [OR], 1.16; 95% confidence interval [CI], 1.15-1.17), overweight (OR, 1.36; 95% CI, 1.35-1.36), and obese (OR, 1.34; 95% CI, 1.33-1.34) groups were more likely to have a normal cognitive function than a normal-weight group. Next, in the case of BMI categories of the WHO method, compared to a normal-weight group, underweight (OR, 1.15; 95% CI, 1.14-1.16) and overweight (OR, 1.06; 95% CI, 1.06-1.07) groups were more likely to have a normal cognitive function; however, obese (OR, 0.62; 95% CI, 0.61-0.63) group was less likely to have it. Lastly, in the case of the 10-group method, as BMI increased, the likelihood to have a normal cognitive function changed like a wave, reaching a global top at group-7 (26.5 kg/㎡ ≤ BMI <28.0 kg/㎡). Conclusion: The associations between BMI and cognitive function differed according to how BMI was categorized among people aged 45 and older in Korea, which suggests that cognitive function may be positively associated with BMI in some categories of BMI but negatively in its other categories. Health policies to reduce cognitive impairment need to consider this association between BMI and cognitive function.