• Korean Journal of Agricultural and Forest Meteorology
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• v.4 no.3
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• pp.133-140
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• 2002

Site-specific minimum temperature forecasts are critical in a short-term decision making procedure for preventive measures as well as a long-term strategy such as site selection in fruits industry. Nocturnal cold air pools frequently termed in mountainous areas under anticyclonic systems are very dangerous to the flowering buds in spring over Korea, but the spatial resolution to detect them exceeds the current weather forecast scale. To supplement the insufficient spatial resolution of official forecasts, we developed a GIS - assisted frost risk assesment scheme for using in mountainous areas. Daily minimum temperature data were obtained from 6 sites located in a 2.1 by 2.1 km area with complex topography near the southern edge of Sobaek mountains during radiative cooling nights in spring 2001. A digital elevation model with a 10 m spatial resolution was prepared for the entire study area and the cold air inflow was simulated for each grid cell by counting the number of surrounding cells coming into the processing cell. Primitive temperature surfaces were prepared for the corresponding dates by interpolating the Korea Meteorological Administration's automated observational data with the lapse rate correction. The cell temperature values corresponding to the 6 observation sites were extracted from the primitive temperature surface, and subtracted from the observed values to obtain the estimation error. The errors were regressed to the flow accumulation at the corresponding cells, delineating a statistically significant relationship. When we applied this relationship to the primitive temperature surfaces of frost nights during April 2002, there was a good agreement with the observations, showing a feasibility of site-specific frost warning system development in mountainous areas.

• The Journal of Engineering Geology
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• v.28 no.3
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• pp.379-395
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• 2018

A walking trail environment can be divided into the upper part of the trail, the trail itself, and the lower part of the trail. In this study, based on field investigations, we developed a risk index for trails by considering human/societal factors that affect each of these three trail environments. A checklist was developed for field investigations, and checklist items were scored through relative importance analysis. The relative weights of items were analyzed using the AHP (Analytic Hierarchy Process) technique, revealing that the upper environment of a trail is twice as important as the rest of the environment. The importance and score of items belonging to each environment were determined. We define the risk index as the sum of the item scores. Weights were added using data from existing investigations including landslides risk rating and designated risk steep slopes. The risk index has a maximum value of 200, and the maximum and minimum calculated scores of 335 risk sections were 159 and 64.2, respectively. As a result of comparative analysis between field observations and risk index calculations, most sections at relatively low risk had risk values less than 100, and sections with high risks or that had been the site of accident yielded scores that exceeded 140.

• Economic Analysis
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• v.27 no.3
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• pp.1-32
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• 2021

This study empirically analyzes whether bank capital channel and risk-taking channel for monetary policy work for domestic banks in South Korea by analyzing the impact of the expansionary monetary policy on the rate spread between deposit and loan, capital ratio, and loan amount. For the empirical analysis, the Uhlig (2005)'s sign-restricted SVAR(Structural Vector Auto-Regression) model is used. The empirical results are as follows: the bank's interest rate margin increases, the capital ratio improves, risk-weighted asset ratio increases, and the amount of loans increases in response to expansionary monetary shock. This empirical results confirm that bank capital channel and risk-taking channel work in domestic banks, similar to the previous research results. The implications of this study are as follows. Although the expansionary monetary policy has the effect of improving the bank's financial soundness and profitability in the short term as bank capital channel works, it could negatively affect the soundness of banks by encouraging banks to pursue risk in the long run as risk-taking channel works. It is necessary to note that the capital ratio according to the BIS minimum capital requirement of individual banks may cause an illusion in supervising the soundness of the bank. So, the bank's aggressive lending expansion may lead to an inherent weakness in the event of a crisis. Since the financial authority may have an illusion about the bank's financial soundness if the low interest rate persists, the authority needs to be actively interested in stress tests and concentration risk management in the pillar 2 of the BIS capital accord. In addition, since system risk may increase, it is necessary to conduct regular stress tests or preemptive monitoring of assets concentration risk.

• Journal of Periodontal and Implant Science
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• v.48 no.4
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• pp.251-260
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• 2018

Purpose: The aim of this retrospective cross-sectional study was to evaluate whether salivary findings of active matrix-metalloproteinase 8 (aMMP-8) chairside (point of care; POC) tests were associated with periodontal risk assessment parameters in patients receiving supportive periodontal therapy (SPT). Methods: A total of 125 patients receiving regular SPT were included, and their records were examined. The following inclusion criteria were used: a diagnosis of chronic periodontitis, at least 1 non-surgical periodontal treatment (scaling and root planning) with following regular SPT (minimum once a year), at least 6 remaining teeth, and clinical and aMMP-8 findings that were obtained at the same appointment. In addition to anamnestic factors (e.g., smoking and diabetes), oral hygiene indices (modified sulcus bleeding index [mSBI] and approximal plaque index), periodontal probing depth simultaneously with bleeding on probing, and dental findings (number of decayed, missing, and filled teeth) were recorded. Salivary aMMP-8 levels were tested using a commercial POC test system (Periomarker, Hager & Werken, Duisburg, Germany). Statistical analysis was performed using the t-test, Mann-Whitney U test, Fisher's exact test, and ${\chi}^2$ test, as appropriate (P<0.05). Results: Only the mSBI was significantly associated with positive salivary aMMP-8 findings (aMMP-8 positive: $27.8%{\pm}20.9%$ vs. aMMP-8 negative: $18.0%{\pm}14.5%$; P=0.017). No significant associations were found between aMMP-8 and smoking, diabetes, periodontal parameters, or parameters related to the maintenance interval (P>0.05). Conclusions: Salivary aMMP-8 chairside findings were not associated with common parameters used for periodontal risk assessment in patients receiving SPT. The diagnostic benefit of POC salivary aMMP-8 testing in risk assessment and maintenance interval adjustment during SPT remains unclear.

• Journal of the Korean Institute of Gas
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• v.1 no.1
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• pp.81-86
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• 1997

This study is to estimate the possibility of accident in chemical plants from the analysis of system component which affects the occurrence of top event. Among the various risk assessment techniques, the Fault Tree Analysis which approaches deductively on the route of accident development was used in this study. By gate-by-gate method and minimal cut set, the qualitative and quantitative risk assessment for hazards in plants was performed. The probability of occurrence and frequency of top event was calculated from failure or reliability data of system components at stage of the quantitative risk assessment. In conclusion, the probability of accident was estimated according to logic pattern based on the Fault Tree Analysis. And the failure path which mostly influences on the occurrence of top event was found from Importance Analysis.

• Journal of Korean Neurosurgical Society
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• v.57 no.2
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• pp.108-113
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• 2015

Objective : Although the L5-S1 has distinct structural features in comparison with other lumbar spine segments, not much is known about adjacent segment degeneration (ASD) at the L5-S1 segment. The aim of study was to compare the incidence and character of ASD of the cephalad and L5-S1 segments after L5 floating lumbar fusion. Methods : From 2005 to 2010, 115 patients who underwent L5 floating lumber fusion were investigated. The mean follow-up period was 46.1 months. The incidence of radiological and clinical ASD of the cephalad and the L5-S1 segments was compared using survival analysis. Risk factors affecting ASD were analyzed using a log rank test and the Cox proportional hazard model. Results : Radiological ASD of the L5-S1 segment had a statistically significant higher survival rate than that of the cephalad segment (p=0.001). However, clinical ASD of the L5-S1 segment was significantly lower survival rates than that of the cephalad segment (p=0.038). Risk factor analysis showed that disc degeneration of the cephalad segment and preoperative spinal stenosis of the L5-S1 segment were risk factors. Conclusion : In L5 floating fusion, radiological ASD was more common in the cephalad segment and clinical ASD was more common in the L5-S1 segment. At the L5-S1 segment, the degree of spinal stenosis appears to be the most influential risk factor in ASD incidences, unlike the cephalad segment.

• Journal of Korean Neurosurgical Society
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• v.46 no.5
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• pp.425-430
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• 2009

Objective : The present study analyzed the risk factors, prevalence and clinical results following revision surgery for adjacent segment degeneration (ASD) in patients who had undergone lumbar fusion. Methods : Over an 8-year period, we performed posterior lumbar fusion in 81 patients. Patients were followed a minimum of 2 years (mean 5.5 years). During that time, 9 patients required revision surgery due to ASD development. Four patients underwent autogenous posterolateral arthrodesis and extended transpedicle screw fixation, 4 patients underwent decompressive laminectomy and interspinous device implantation, and 1 patient underwent simple decompression. Results : Of the 9 of patients with clinical ASD, 33.3% (3 of 9) of patients did not have radiographic ASD on plain radiographs. Following revision surgery, the clinical results were excellent or good in 8 patients (88.9%). Age > 50 years at primary surgery was a significant risk factor for ASD development, while number of fusion levels, initial diagnosis and type of fusion were not. Conclusion : The incidence of ASD development after lumbar surgery was 11.1% (9 of 81) in this study. Age greater than 50 was the statistically significant risk factor for ASD development. Similar successful clinical outcomes were observed after extended fusion with wide decompression or after interspinous device implantation. Given the latter procedure is less invasive, the findings suggest it may be considered a treatment alternative in selected cases but it needs further study.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.9
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• pp.5207-5212
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• 2013

Background: Physical activity has been found to play a role in cancer prevention. The purpose of this matched case-control study was to investigate the association between physical activity levels, water intake, constipation and colorectal cancer (CRC). Materials and Methods: Two hundred and thirty-two patients diagnosed with CRC (125 male, 107 female) were enrolled in this case-control study. Cases were matched to 271 population controls (137 male, 134 female). Results: Drinking more than 4 cups of water daily decreased the risk of CRC by 33-42%; however, this effect was non-significant. Having constipation was found to be a significant risk factor for developing CRC with an OR=6.284 (95%CI=2.741-14.40). With reference to sedentary behavior, minimum activity (600-3000 Metabolic Equivalents Task (MET)) had 43% protection against CRC and the level of Health Enhancing Physical Activity OR was 0.58 (at 95%CI; 0.37-0.92). A significant negative association was found between CRC and physical activity levels expressed as both METs and MET-hours/week (p for trend=0.017 and 0.03, respectively). Among females, a significant trend of reduction in CRC by 62% was observed with increasing the level of physical activity expressed in MET (p for trend=0.04). Conclusions: The risk of CRC may be reduced by adopting a healthy lifestyle and practicing physically activity regularly, especially among females. Consuming adequate amounts of water and healthy bowel motility could also reduce the risk of CRC.

• Physical Therapy Rehabilitation Science
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• v.11 no.1
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• pp.66-77
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• 2022

Objective: This study is a systematic review conducted to analyze the environmental factors that cause falls in the older adult. Design: Systematic review Methods: The study was conducted by searching the Research Information Sharing Service (RISS), Korean studies Information Service System (KISS), and Data Base Periodical Information Academic (DBpia) databases for literature published in South Korea up to July 2020. A total of 12 studies were selected for analysis based on the inclusion and exclusion criteria. Results: The results of the analysis revealed that all the selected literature were surveys and the study subjects were 65 years of age and above. The sample size ranged from a minimum of 95 subjects to a maximum of 3,278. A total of eight tools were used to measure the environmental factors associated with falls. The prevalence and recurrence of falls increase with age and deterioration of health. Older adult individuals who experience falls encounter difficulties in recovering from impaired physical function and disability; moreover, in severe cases, falls may lead to death. Falls are largely associated with a combination of intrinsic and extrinsic (i.e., environmental) factors. The purpose of this study was to assess potential extrinsic risk factors for falls. Falls occur in indoor environments, such as washrooms, bathrooms and living rooms, and outdoor environments, including roads and stairways, depending on the season, time of day, and use of ambulatory aids. In such environments, falls are mainly caused by slipping and stuttering. Conclusions: Therefore, as the rate of fall is influenced by several factors, extrinsic factors should be improved by developing comprehensive accident prevention programs that address the improvement of environmental risk factors around places of residence to reduce risk factors among the older adult, who, especially, are at a high risk for falls.

• Journal of Aerospace System Engineering
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• v.17 no.6
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• pp.46-53
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• 2023

As urban traffic congestion and environmental pollution are becoming significant issues in major cities, Urban Air Mobility (UAM) is gaining attention as an efficient solution. In this study, we conducted a geographic information system (GIS)-based spatial analysis and clustering algorithm considering the actual data of the terrain and infrastructure in the Busan area, through which we were able to select the location of vertiports and corridors (flight routes) for the UAM operation. Based on the Gimhae International Airport, which is expected to be the center of the UAM infrastructure system in the Busan region, we judged that three vertiport locations in the target area were suitable. Subsequently, we used the A^* (A-star) algorithm considering Ground Risk to select a flight path that minimized both risk and distance. Through this, we confirmed a risk reduction effect of 80.168% compared to the minimum distance route.