• Special Issue of the Society of Naval Architects of Korea
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• 2005.06a
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• pp.113-126
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• 2005

This paper describes introductory remarks on risk management and risk-based design for ships and offshore installations with potential hazards. Clients' requirements on safety and performance was related to the risk management and risk-based design. A general procedure for risk-based design was also suggested with each step explained in detail. Various risk-based design approaches were emphasized with their needs and methodological characteristics taken into account. Related rules, standards, and regulations were summarized. The last part included recommendations for Korean ship building industries about the risk management and risk-based design.

• Corrosion Science and Technology
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• v.16 no.5
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• pp.235-240
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• 2017

Regional cathodic protection has significant impact on pipeline integrity management. After risk analyses of a newly built gas distribution station constructed in an area with large dwelling density, risk score was high because of potential threat caused by galvanic corrosion. Except reinforced steel in concrete, there are four kinds of metal buried under earth: carbon steel, galvanized flat steel, zinc rod and graphite module. To protect buried pipeline from external corrosion, design and construction of regional cathodic protection was proposed. Current density was measured with potential using potential dynamic test and boundary element method (BEM) was used to calculate current requirement and optimize best anode placement during design. From our calculation on the potential, optimized conditions for this area were that an applied current was 3A and anode was placed at 40 meters deep from the soil surface. It results in potential range between $-1.128V_{CSE}$ and $-0.863V_{CSE}$, meeting the $-0.85V_{CSE}$ criterion and the $-1.2V_{CSE}$ criterion that no potential was more negative than $-1.2V_{CSE}$ to cause hydrogen evolution at defects in coating of the pipeline.

• Nutrition Research and Practice
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• v.10 no.1
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• pp.89-98
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• 2016

BACKGROUND/OBJECTIVES: Observational studies suggest that an association between vegetable consumption and coronary heart disease (CHD). However, the results are inconsistent. This study aimed to investigate the daily intake of vegetables on a national level and its effect on the risk of CHD risk, as determined by the Framingham Risk Score (FRS). SUBJECTS/METHODS: This study was conducted a cross-sectional design of 2,510 male adults 40-64y of age who participated in the 2007-2009 Korean National Health and Nutrition Examination Survey. Daily intake of vegetable was assessed by 24-h recall, and the consumption frequency of vegetables was determined using a food frequency questionnaire. The odd ratio of CHD risk according to daily intake and frequency of vegetables was analyzed. RESULTS: Total vegetable intake was inversely and significantly associated with the risk of CHD (Model 1: 4th vs. 1st quartile, OR = 0.74, 95% CI = 0.58-0.96, P for trend = 0.0015), and the significant relationship with CHD risk remained even after adjusting for potential confounders (Model 3: 4th vs. 1st quartile, adjusted OR [aOR] = 0.69, 95% CI = 0.49-0.95, P for trend = 0.0492). Subjects in the higher quartiles of non-salted vegetable intake had 31% lower odds of the risk of CHD compared to those in the lowest quartile after adjusting for various potential confounders in model 3 (aOR = 0.69; 95% CI = 0.49-0.97, P for trend = 0.0478). No significant associations between the frequency of vegetable intake (total, green, white and red vegetable) and the risk of CHD were found. CONCLUSIONS: The major results of this study indicate that higher vegetable intake may help prevent CHD in Korean men.

• Journal of Korea Water Resources Association
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• v.52 no.2
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• pp.125-132
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• 2019

In this study, we developed a heavy rainfall risk impact matrix, which can be used to evaluate the influence of heavy rainfall risk, and propose a method to evaluate the impact of heavy rainfall risk. We evaluated the heavy rainfall risk impact for each receptor (Residential, Transport, Utility) on Sadang-dong using the heavy rainfall event on July 27, 2011. For this purpose, the potential risk impact was calculated by combining the impact level and the rainfall depth based on the grid. Heavy Rainfall Risk Impact was calculated by combining with Likelihood to predict the heavy rainfall impact, and the degree of heavy rainfall in the Sadang-dong area was analyzed and presented based on grid.

• Journal of the Korean Society of Radiology
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• v.11 no.6
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• pp.483-491
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• 2017

This study investigates the perception of the general public through analysis of various potential risk factors reflecting nuclear power generation and nuclear power (radiation) and risks. A total of 293 copies of the data were collected from various strata in Busan. As a result, among the potential factors in everyday life, there was a high awareness of the risk to the fire. Next, the perception of risk for radiation terror and nuclear (nuclear) energy was relatively high compared to other risk factors. In the analysis according to age, educational background, and political ideological tendency, the results were contradictory to the necessity, risk and safety of nuclear power generation. The potential risk factors and the perception of nuclear power according to the tendency of political ideology were analyzed to be positive recognition of conservative ideology and negative recognition of progressive group. In other words, the perception of nuclear power was analyzed differently according to the tendency of political ideology. Therefore, it should be decided to reflect the opinions of experts and various opinions of the general public in the setting of nuclear radiation (radiation), it is believed that ordinary people need to take flexible action without having a vague sense of anxiety about various potential risks and nuclear power (radiation) based on objective and scientific grounds.

• Journal of Korean Neurosurgical Society
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• v.67 no.1
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• pp.60-72
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• 2024

Objective : Recently, robotic-assisted spine surgery (RASS) has been considered a minimally invasive and relatively accurate method. In total, 495 robotic-assisted pedicle screw fixation (RAPSF) procedures were attempted on 100 patients during a 14-month period. The current study aimed to analyze the accuracy, potential risk factors, and learning curve of RAPSF. Methods : This retrospective study evaluated the position of RAPSF using the Gertzbein and Robbins scale (GRS). The accuracy was analyzed using the ratio of the clinically acceptable group (GRS grades A and B), the dissatisfying group (GRS grades C, D, and E), and the Surgical Evaluation Assistant program. The RAPSF was divided into the no-breached group (GRS grade A) and breached group (GRS grades B, C, D, and E), and the potential risk factors of RAPSF were evaluated. The learning curve was analyzed by changes in robot-used time per screw and the occurrence tendency of breached and failed screws according to case accumulation. Results : The clinically acceptable group in RAPSF was 98.12%. In the analysis using the Surgical Evaluation Assistant program, the tip offset was 2.37±1.89 mm, the tail offset was 3.09±1.90 mm, and the angular offset was 3.72°±2.72°. In the analysis of potential risk factors, the difference in screw fixation level (p=0.009) and segmental distance between the tracker and the instrumented level (p=0.001) between the no-breached and breached group were statistically significant, but not for the other factors. The mean difference between the no-breach and breach groups was statistically significant in terms of pedicle width (p<0.001) and tail offset (p=0.042). In the learning curve analysis, the occurrence of breached and failed screws and the robot-used time per screw screws showed a significant decreasing trend. Conclusion : In the current study, RAPSF was highly accurate and the specific potential risk factors were not identified. However, pedicle width was presumed to be related to breached screw. Meanwhile, the robot-used time per screw and the incidence of breached and failed screws decreased with the learning curve.

• Journal of Cadastre & Land InformatiX
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• v.47 no.1
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• pp.37-51
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• 2017

Despite the improvement in accuracy of heavy rain forecasting, socioeconomic costs due to heavy rain hazards continue to increase. This is due to a lack of understanding of the effects of weather. In this study, the risk of heavy rain hazard was analyzed using the concepts of hazard, vulnerability, and exposure, which are key concepts of impact forecast presented by WMO. The potential impacts were constructed by the exposure and vulnerability variables, and the hazard index was calculated by selecting three variables according to the criteria of heavy rain warning. Weights of the potential impact index were calculated by using PCA and hazard index was calculated by applying the same weight. Correlation analysis between the potential impact index and damages showed a high correlation and it was confirmed that the potential impact index appropriately reflects the actual damage pattern. The heavy rain hazard risk was estimated by using the risk matrix consisting of the heavy rain potential impact index and the hazard index. This study provides a basis for the impacts analysis study for weather warning with spatial/temporal variation and it can be used as a useful data to establish the local heavy rain hazard prevention measures.

• Environmental Analysis Health and Toxicology
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• v.28
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• pp.2.1-2.7
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• 2013

Objectives Tricalcium phosphate and calcium hydrogenorthophosphate are high production volume chemicals, mainly used as foodstuff additives, pharmaceuticals, lubricants, synthetic resin, and disinfectants. Phosphate has the potential to cause increased algal growth leading to eutrophication in the aquatic environment. However, there is no adequate information available on risk assessment or acute and chronic toxicity. The aim of this research is to evaluate the toxic potential of phosphate compounds in the aquatic environment. Methods An aquatic toxicity test of phosphate was conducted, and its physico-chemical properties were obtained from a database recommended in the Organization for Economic Cooperation and Development (OECD) guidance manual. An ecotoxicity test using fish, Daphnia, and algae was conducted by the good laboratory practice facility according to the OECD TG guidelines for testing of chemicals, to secure reliable data. Results The results of the ecotoxicity tests of tricalcium phosphate and calcium hydrogenorthophosphate are as follows: In an acute toxicity test with Oryzias latipes, 96 hr 50% lethal concentration ($LC_{50}$) was >100 (measured:>2.14) mg/L and >100 (measured: >13.5) mg/L, respectively. In the Daphnia test, 48 hr 50% effective concentration ($EC_{50}$) was >100 (measured: >5.35) mg/L and >100 (measured: >2.9) mg/L, respectively. In a growth inhibition test with Pseudokirchneriella subcapitata, 72 hr $EC_{50}$ was >100 (measured: >1.56) mg/L and >100 (measured: >4.4) mg/L, respectively. Conclusions Based on the results of the ecotoxicity test of phosphate using fish, Daphnia, and algae, $L(E)C_{50}$ was above 100 mg/L (nominal), indicating no toxicity. In general, the total phosphorus concentration including phosphate in rivers and lakes reaches levels of several ppm, suggesting that phosphate has no toxic effects. However, excessive inflow of phosphate into aquatic ecosystems has the potential to cause eutrophication due to algal growth.

• Journal of Environmental Impact Assessment
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• v.31 no.5
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• pp.321-333
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• 2022

In this study, the concentration and distribution characteristics of BTEX (benzene toluene, ethylbenzene, and xylene) emitted from Daesan Petrochemical Industrial Complex were examined to determine their potential hazards to local residents. Residents living nearby the complex areas may be exposed to the chemicals through various media (air, water, and soil), especially by air. This study evaluated human health risks by inhalation using both deterministic and probabilistic risk assessment approaches. As a result of the deterministic risk assessment, the non-cancer risk was much lower than the regulation limit of hazard index (HI 1.0) for all the points. However, in case of cancer risk evaluation, it was found that the risk of excess cancer for benzene at point A located in the industrial complex was 2.28×10^-6, which slightly exceeded the standard regulatory limit of 1.0×10^-6. In addition, the probabilistic risk assessment revealed that the percentile exceeding the standard of 1.0×10^-6was found to be 45.3%. The sensitivity analysis showed that exposure time (ET) had the greatest impact on the results. Based on the risk assessment study, it implied that ethylbenzene, toluene, and xylene had little adverse effects on potential human exposure, but benzene often exceeded the cancer risk standard (1.0×10^-6). Further studies on extensive VOCs monitoring are needed to evaluate the potential risks of industrial complex areas.

• Journal of Korea Water Resources Association
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• v.57 no.4
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• pp.277-287
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• 2024

Water distribution system (WDS) is exposed to various water quality incidents during its operation. This study utilized Quantitative Microbial Risk Assessment (QMRA) to analyze the risk associated with potential virus intrusion in WDSs. Additionally, the study determined the location and operation of rechlorination facilities to minimize potential risk. In addition, water quality resilience was calculated to confirm that the chlorine concentration maintains within the target range (0.1-1.0 mg/L) during normal operation. Hydraulic analysis was performed using EPANET, while EPANET-MSX was linked to simulate the reactions between viruses and chlorine. The proposed methodology was applied to the Bellingham network in the United States, where rechlorination facilities capable of injecting chlorine concentrations ranging from 0.5 mg/L to 1.0 mg/L were considered. Results indicated that without rechlorination facilities, the Average risk was 0.0154. However, installing rechlorination facilities and injecting chlorine at a concentration of 1.0 mg/L could reduce the Average risk to 39.1%. It was observed that excessive chlorine injection through rechlorination facilities reduced water quality resilience. Consequently, a rechlorination facility with a concentration of 0.5 mg/L was selected, resulting in a reduction of approximately 20% in average risk. This study provides insights for designing rechlorination facilities to enhance preparedness against potential virus ingress in the future.