• Korean Journal of Radiology
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• v.22 no.7
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• pp.1152-1162
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• 2021

Objective: This study aimed to determine whether there are regional differences in the blood-brain barrier (BBB) permeability of cognitively normal elderly participants and to identify factors influencing BBB permeability with a clinically feasible, 10-minute dynamic contrast-enhanced (DCE) MRI protocol. Materials and Methods: This IRB-approved prospective study recruited 35 cognitively normal adults (26 women; mean age, 64.5 ± 5.6 years) who underwent DCE T1-weighted imaging. Permeability maps (K_trans) were coregistered with masks to calculate the mean regional values. The paired t test and Friedman test were used to compare Ktrans between different regions. The relationships between K_trans and the factors of age, sex, education, cognition score, vascular risk burden, vascular factors on imaging, and medial temporal lobar atrophy were assessed using Pearson correlation and the Spearman rank test. Results: The mean permeability rates of the right and left hippocampi, as assessed with automatic segmentation, were 0.529 ± 0.472 and 0.585 ± 0.515 (K_trans, x 10^-3 min^-1), respectively. Concerning the deep gray matter, the K_trans of the thalamus was significantly greater than those of the putamen and hippocampus (p = 0.007, p = 0.041). Regarding the white matter, the K_trans value of the occipital white matter was significantly greater than those of the frontal, cingulate, and temporal white matter (p < 0.0001, p = 0.0007, p = 0.0002). The variations in K_trans across brain regions were not related to age, cognitive score, vascular risk burden, vascular risk factors on imaging, or medial temporal lobar atrophy in the study group. Conclusion: Our study demonstrated regional differences in BBB permeability (K_trans) in cognitively normal elderly adults using a clinically acceptable 10-minutes DCE imaging protocol. The regional differences suggest that the integrity of the BBB varies across the brains of cognitively normal elderly adults. We recommend considering regional differences in K_trans values when evaluating BBB permeability in patients with neurodegenerative diseases.

• East Asian Economic Review
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• v.19 no.4
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• pp.357-379
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• 2015

We investigate interconnectedness and the contagion effect of default risk in Asian sovereign CDS markets since the global financial crisis. Using dynamic conditional correlation analysis, we find that there are significant co-movements in Asian sovereign CDS markets; that such co-movements tend to be larger between developing countries than between developed and developing countries; and that in the co-movements intra-regional nature is stronger than inter-regional nature. With the Spillover Index model, we measure contagion probabilities of sovereign default risk in CDS markets of seven Asian countries and find evidence of contagion effects among six of them; Japan is the exception. In addition, we find that these six countries are affected more by cross-market spillovers than by their own-market spillovers. Furthermore, a rolling-sample analysis reveals that contagion in the Asian sovereign CDS markets expands during episodes of extreme economic and financial distress, such as the Lehman Brothers bankruptcy, the European financial crisis, and the US-credit downgrade.

• Journal of the Regional Association of Architectural Institute of Korea
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• v.20 no.6
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• pp.25-32
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• 2018

According to the data released by Korea Occupational Safety & Health Agency, construction workers suffering from falling disaster have been increasing continuously for the last five years, and in fact, small and medium construction companies' falling disaster forms over 97% of all every year. This means that to reduce falling disaster significantly, it is needed to get rid of disaster taking place in small and medium construction companies. Here, this study aims to analyze various causes of falling disaster in small and medium construction companies, examine how those factors are correlated with one another, and suggest how to manage the risk of falling disaster effectively. According to the study results, main factors influencing falling disaster in small and medium construction companies are found as follows: Situational Awareness/Risk Perception, Fatigue/Alertness, Communications, Equipment/Facilities, and Personal Protective Equipment (PPE) in the Direct Level, Management/Supervision, Education/Training, and Planning in the Organizational Level, and Management's Commitment to Safety in the Policy Level.

• Clinical and Experimental Pediatrics
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• v.54 no.12
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• pp.481-488
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• 2011

In the current era of low-birth rate in Korea, it is important to improve our neonatal intensive care and to establish an integrative system including a regional care network adequate for both high-risk pregnancies and high-risk newborn infants. Therefore, official discussion for nation-wide augmentation, proper leveling, networking, and regionalization of neonatal and perinatal care is urgently needed. In this report, I describe the status of neonatal intensive care in Korea, as well as nationwide flow of transfer of high-risk newborn infants and pregnant women, and present a short review of the regionalization of neonatal and perinatal care in the Unites States and Japan. It is necessary not only to increase the number of neonatal intensive care unit (NICU) beds, medical resources and manpower, but also to create a strong network system with appropriate leveling of NICUs and regionalization. A systematic approach toward perinatal care, that includes both high-risk pregnancies and newborns with continuous support from the government, is also needed, which can be spearheaded through the establishment of an integrative advisory board to propel systematic care forward.

• Journal of the Korean Society for Railway
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• v.7 no.2
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• pp.99-106
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• 2004

This paper presents the procedures and the results conducted by the proposed one for the risk assessment based on the accident statistics in the Korean railway. Approximately 1200 accident data were used for this study, and risk models were developed to describe the potential hazards. A risk assessment was conducted using the potential problem analysis technique qualitatively. Additionally, this study performed a regional risk assessment. The results of this study showed that the risks for collisions between trains and derailment are relatively low. However, grade crossing and public accident and accidents of workers on tracks take high risks. A large number of accidents is concentrated on the three regions such as Suwon, Chunan, and Chungrangri.

• International Journal of Safety
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• v.9 no.1
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• pp.35-42
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• 2010

We measured the concentrations of air pollutants at several residential sites, roadside sites and industrial sites in Iwate Prefecture, Japan. And the concentration distributions of air pollutants were estimated by atmospheric dispersion model using air emissions data. Based on those results, we calculated environmental risk of air pollutants emitted in Iwate Prefecture. As a result, it was found that the surround of factories with high emissions and highly toxic chemicals and the roadsides were high risk area, benzo(a)pyrene, formaldehyde and ozone exceeded the $10^{-5}$ risk level. Moreover, we tried to use "Loss of life expectancy: LLE" for an index to explain those risk to general public intelligibly. The total LLE of the carcinogenic chemicals was about 8.6 hours. Moreover, LLE of ozone was about 9.2 hours. Ozone has a big influence compared with the carcinogenic chemicals.

• Journal of Trauma and Injury
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• v.31 no.3
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• pp.181-188
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• 2018

Urgent reduction is required in cases of traumatic hip dislocation to reduce the risk of avascular necrosis of the femoral head. However, in cases of femoral head fractures, the dislocated hip cannot be reduced easily, and in some cases, it can even be irreducible. This irreducibility may provoke further incidental iatrogenic fractures of the femoral neck. In an irreducible hip dislocation, without further attempting for closed reduction, an immediate open reduction is recommended. This can prevent iatrogenic femoral neck fracture or avascular necrosis of the femoral head, and save the natural hip joint.

• Journal of Korea Water Resources Association
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• v.52 no.12
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• pp.985-999
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• 2019

Over the last decade, droughts have become more severe and frequent in many regions, and several studies have been conducted to explore the recent drought. Copula-based bivariate drought frequency analysis has been widely used to evaluate drought risk in the context of point frequency analysis. However, the relatively significant uncertainties in the parameters are problematic when available data are limited. For this reason, the primary purpose of this study is to develop a regional drought frequency model based on the Copula function. All parameters, including marginal and copula functions in the regional frequency model, were estimated simultaneously. Here, we present a case study of recent drought 2013-2015 over the Han-River watershed where severe drought risk is consistently found to increase. The proposed model provided a reliable way to significantly reduce the uncertainty of parameters with a Bayesian modeling framework. The uncertainty of the joint return period in the regional frequency analysis is nearly three times lower than that of the point frequency analysis. Accordingly, DIC values in the regional frequency analysis model are significantly decreased by 15. The results confirm that the proposed model is not only reliably representing characteristics of historical droughts and dependencies between drought variables, but also providing the efficacy of understanding regional drought characteristics.

• Journal of Trauma and Injury
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• v.37 no.1
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• pp.28-36
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• 2024

Purpose: Recent advancements in interventional radiology have made angioembolization an invaluable modality in trauma care. Angioembolization is typically performed by interventional radiologists. In this study, we aimed to investigate the safety and efficacy of emergency angioembolization performed by trauma surgeons. Methods: We identified trauma patients who underwent emergency angiography due to significant trauma-related hemorrhage between January 2020 and June 2023 at Jeju Regional Trauma Center. Until May 2022, two dedicated interventional radiologists performed emergency angiography at our center. However, since June 2022, a trauma surgeon with a background and experience in vascular surgery has performed emergency angiography for trauma-related bleeding. The indications for trauma surgeon-performed angiography included significant hemorrhage from liver injury, pelvic injury, splenic injury, or kidney injury. We assessed the angiography results according to the operator of the initial angiographic procedure. The term "failure of the first angioembolization" was defined as rebleeding from any cause, encompassing patients who underwent either re-embolization due to rebleeding or surgery due to rebleeding. Results: No significant differences were found between the interventional radiologists and the trauma surgeon in terms of re-embolization due to rebleeding, surgery due to rebleeding, or the overall failure rate of the first angioembolization. Mortality and morbidity rates were also similar between the two groups. In a multivariable logistic regression analysis evaluating failure after the first angioembolization, pelvic embolization emerged as the sole significant risk factor (adjusted odds ratio, 3.29; 95% confidence interval, 1.05-10.33; P=0.041). Trauma surgeon-performed angioembolization was not deemed a significant risk factor in the multivariable logistic regression model. Conclusions: Trauma surgeons, when equipped with the necessary endovascular skills and experience, can safely perform angioembolization. To further improve quality control, an enhanced training curriculum for trauma surgeons is warranted.

• Magazine of the Korea Institute for Structural Maintenance and Inspection
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• v.20 no.1
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• pp.17-21
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• 2016