• Transactions of the Korean hydrogen and new energy society
• /
• v.35 no.1
• /
• pp.66-74
• /
• 2024

This study addresses the escalating issue of worldwide hydrogen gas accidents, which has seen a significant increase in occurrences. To comprehensively evaluate the risks associated with hydrogen, a two approach was employed in this study. Firstly, a qualitative risk assessment was conducted using the bow-tie method. Secondly, a quantitative consequence analysis was carried out utilizing the areal locations of hazardous atmospheres (ALOHA) model. The study applied this method to two incidents, the hydrogen explosion accident occurred at the Muskingum River power plant in Ohio, USA, 2007 and the hydrogen storage tank explosion accident occurred at the K Technopark water electrolysis system in Korea, 2019. The results of the risk assessments revealed critical issues such as deterioration of gas pipe, human errors in incident response and the omission of important gas cleaning facility. By analyzing the cause of accidents and assessing risks quantitatively, the effective accident response plans are proposed and the effectiveness is evaluated by comparing the effective distance obtained by ALOHA simulation. Notably, the implementation of these measures led to a significant 54.5% reduction in the risk degree of potential explosions compared to the existing risk levels.

• Annals of Occupational and Environmental Medicine
• /
• v.35
• /
• pp.3.1-3.11
• /
• 2023

Background: Studies on the risk of mercury (Hg) in Korean fishery products focus primarily on total Hg levels as opposed to methylmercury (MeHg) levels. None of the few studies on MeHg in tuna investigated tuna from Japanese restaurants. Few have evaluated lead (Pb), cadmium (Cd) and arsenic (As) in tuna. Thus, this study aimed to conduct a risk assessment by evaluating heavy metal concentrations in tuna from Japanese restaurants. Methods: Thirty-one tuna samples were collected from Japanese restaurants in the Republic of Korea. They were classified according to region and species. The concentration of heavy metals in the samples was analyzed using the Ministry of Food and Drug Safety Food Code method. The rate of exceedance of maximum residue levels (MRLs) and the risk compared to the provisional tolerable weekly intake (PTWI) set by the Joint Food and Agriculture Organization/World Health Organization Expert Committee on Food Additives (%PTWI) were evaluated for risk assessment. Results: The mean of MeHg, Pb, Cd and As concentrations were 0.56 ± 1.47 mg/kg, 33.95 ± 3.74 ㎍/kg, 14.25 ± 2.19 ㎍/kg and 1.46 ± 1.89 mg/kg, respectively. No sample exceeded the MRLs of Pb and Cd, but 9.7% of the samples exceeded the MRL of MeHg. The %PTWIs of MeHg, Pb, Cd and As were 4.2037, 0.0162, 0.0244 and 1.1627, respectively. The %PTWI of MeHg by age group and sex was highest among men aged 19-29 years (10.6494), followed by men aged 30-49 years (7.2458) and women aged 19-29 years (4.8307). Conclusions: We found that 3 out of 31 samples exceeded the MRL of MeHg. The %PTWI of MeHg showed significant differences based on age and sex, and the value was likely to exceed a safe level depending on individuals' eating behaviors. Therefore, improved risk management for MeHg is required.

• Nuclear Engineering and Technology
• /
• v.39 no.2
• /
• pp.123-128
• /
• 2007

In order to apply a static fault-tree (FT) method to a system or a plant whose configuration changes dynamically, condition gates and a post processing method are used to effectively accommodate these changes. An operator's performance change, which can be caused by these configuration changes, should also be considered to assess the risk to a plant in a more realistic manner. This study aims to develop an integrated framework to accommodate various configuration changes and their effect on an operator’s performance by using the FT model. We applied a condition-based human reliability assessment (CBHRA) method to consider various conditions endured by an operator. That is, we integrated the CBHRA method with the conventional post processing method for modeling the system configuration changes. The effect of the condition monitoring systems installed in a plant is also considered. In this study, we show an example application of the integrated framework to a probabilistic safety assessment for the shutdown phase of a nuclear power plant.

• Journal of Environmental Impact Assessment
• /
• v.15 no.6
• /
• pp.373-383
• /
• 2006

The spatial mapping of risk is very useful data in planning for disaster preparedness. This research presents a methodology for making the landslide life risk map in the Boeun area which had considerable landslide damage following heavy rain in August, 1998. We have developed a three-stage procedure in spatial data analysis not only to estimate the probability of the occurrence of the natural hazardous events but also to evaluate the uncertainty of the estimators of that probability. The three-stage procedure consists of: (i)construction of a hazard prediction map of "future" hazardous events; (ii) validation of prediction results and estimation of the probability of occurrence for each predicted hazard level; and (iii) generation of risk maps with the introduction of human life factors representing assumed or established vulnerability levels by combining the prediction map in the first stage and the estimated probabilities in the second stage with human life data. The significance of the landslide susceptibility map was evaluated by computing a prediction rate curve. It is used that the Bayesian prediction model and the case study results (the landslide susceptibility map and prediction rate curve) can be prepared for prevention of future landslide life risk map. Data from the Bayesian model-based landslide susceptibility map and prediction ratio curves were used together with human rife data to draft future landslide life risk maps. Results reveal that individual pixels had low risks, but the total risk death toll was estimated at 3.14 people. In particular, the dangerous areas involving an estimated 1/100 people were shown to have the highest risk among all research-target areas. Three people were killed in this area when landslides occurred in 1998. Thus, this risk map can deliver factual damage situation prediction to policy decision-makers, and subsequently can be used as useful data in preventing disasters. In particular, drafting of maps on landslide risk in various steps will enable one to forecast the occurrence of disasters.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.56 no.4
• /
• pp.299-315
• /
• 2020

Tuna fisheries were applied to an integrated ecosystem-based fishery risk assessment method using indexes of target species status, inhabited species in a target ecosystem, habitat quality and socio-economic benefit of affected fisheries. This study suggested more effective and efficient management measures to break away from traditional management methods, such as limitation of catch and fishing effort. The results presented that the objective risk index (ORI_S) on sustainability of bigeye and yellowfin tunas by purse seine fishery was estimated high due to the high catch ratio of small fishes. The ORIs of biodiversity (ORI_B) and habitat quality (ORI_H) of purse seine fishery were also estimated at a high level from using fish-aggregating devices (FAD). However, due to skipjack tuna's high catches, the ORI of socio-economic benefit (ORI_E) was estimated at a very low level. Due to the high bycatch rate, ORI_B was high, and ORI_S and ORI_H were evaluated at a low level in longline fishery. Due to strengthern of fishing restrictions and increase of fishing costs, the ORI_E was assessed to be very high. The ecosystem risk index (ERI) for two tuna fisheries was assessed low, but the overall FAD management by purse seine fishery is necessary at the ecosystem level.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.31 no.6
• /
• pp.1261-1266
• /
• 2021

Existing information security risk assessment methods focus on evaluating the vulnerability of information assets. However, when the form of information assets changes and new types of information assets emerge, there is a limitation in that the evaluation standards for them are also added or deleted. Existing methods have insufficient research on the path through which cyber threats are introduced. In particular, there is very little research on blocking the inflow path for web-based information systems with public IPs. Therefore, this paper introduces the main research contents of the BDLA (Blockade and Defense Level Analysis)-based information security risk assessment model. In addition, by applying the BDLA-based information security risk assessment model, the information security risk level was studied by measuring the blockade level and security equipment level of 17 public institutions.

• Journal of Nutrition and Health
• /
• v.42 no.3
• /
• pp.234-245
• /
• 2009

Nutritional assessment for the elderly can identify health status and morbidity. However, development of Nutritional Risk Index (NRI) remains limited for elderly because of difficulties in understanding physiological mechanism of elderly. This study was performed to analyze and develop Nutritional Risk Index for Korean elderly Women (Geriatric Nutritional Risk Index, GNRI). Based on literature review, factors for NRI were identified and indices were assessed by a cross-sectional survey. The survey involved Korean elderly women (${\geq}$60, n = 94) in Gwangju area, and sociodemographics, lifestyle characteristics, health conditions, dietary intakes based on 24h- recall, anthropometric measures (wt, ht, BMI, waist, hip, WHR, body protein, body fat, abdominal fat, and triceps skinfold thickness), and clinical biochemistry parameters (systolic blood pressure, diastolic blood pressure, cholesterol, HDL-cholesterol, triglyceride, total protein, albumin, prealbumin, hemoglobin, hematocrit, fasting blood glucose, HbAlc, ferritin, Zn, Ca, Na, K, Vit E, Vit $B_{12}$, folate, C-reactive protein) were examined relation to nutritional risk index. Based on literature review and data analyses, three NRIs were categorized (NRI I, NRI II, NRI III) and used for further analysis. NRI I was related to having metabolic syndrome, NRI II was related to serum albumin and body weight, and NRI III was related to food habit and health concerns. Abdominal fat (%) of elderly was correlated with each NRIs. NRI II was correlated with nutritional deficiency and higher tendency of inflammatory response, and NRI III was correlated with nutritional status which tend to be lower on aging (protein, folate, Vit $B_{12}$). NRI can serve as a useful tools in assessing health risk and nutritional status. Some modification of items in NRI and validity study are need to apply to Korean elderly.

• Spatial Information Research
• /
• v.23 no.2
• /
• pp.39-48
• /
• 2015

In this study, we evaluated flood risk by applying calculation fomula considering practical risk calculated by inundation analysis information through 2D inundation analysis, suggested a plan that provides a standardized information system. Generally, we evaluated flood risk to people and classified four degrees by using inundation depth, velocity, Debris Factor and Flood Hazard Rating relationship because current flood risk assessment method based inundation depth and area was considered to not fully reflect the actual risk to people on flood. We simulated overflow and levee break scenarios according to 500 year and 200 year floods, respectively, by using Flumen which is a 2D flood inundation model for Geumho river basin in Daegu. The result of this study could contribute to inform practical risk information to people in expected flood area. This study can be useful for the fields of disaster estimatingsuch as information analysis, evaluation, planning by offering Risk information based on standardized information system.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.19 no.2
• /
• pp.88-95
• /
• 2009

There are many assessment techniques used for occupational risk factors of MSDs in the workplaces. However, because all ergonomic assesment techniques or tools are based on theoretical background derived from workphysiology, biomechanics, psychophysics, industrial hygiene, work system, and etc, it is impossible to compare the assessment techniques. This study was conducted to compare the excess rates of risk factors among ergonomic assessment techniques and to make alternative methods. Site-visits to 6 automobile products and parts company provided data for process repeated work where the produced data was examined for evaluating the relationship between workplace lay-out and work posture by using ergonomic assessment techniques. We evaluated 157 jobs for simple repeated work and 37 jobs for manual materials handling (MMH). In simple repeated work, the exceeded rates of AC were 36.3% in OWAS method and 93.0% in RULA method. The exceeded rate for RULA method was significantly higher than those for OWAS method (p<0.05). In MMH, the exceeded rates of AC were 80.0% in NLE method and 76.5% in WAC method. Statistically significant differences were not identified in the exceeded rates for NLE and MAC methods (p<0.05). The analyzed results among ergonomic assessment techniques (OWAS, RULA, NLE/WAC) were applied to the same work places performing simple repeated work and manual materials handling simultaneously. The applied results showed statistically significant differences (p<0.05) among ergonomic assessment techniques (OWAS, RULA, NLE/WAC). Exceeded rates of four ergonomic assessment techniques in decreasing order was "RULA>NLE>WAC>OWAS". The RULA method was the strongest assessment technique for automobile products and parts company. We discovered that the results could easily be overestimated or underestimated when the ergonomic assessment techniques were not applied correctly during the evaluation process. Therefore, we recommend using at least 2 methods when evaluating and analysing the results.

• Journal of the Society of Disaster Information
• /
• v.18 no.3
• /
• pp.520-531
• /
• 2022

Purpose: Based on the risk evaluation of hydrogen fueling stations, this study aims to find a plan to strengthen management safety by examining profitability and management risk, which are major concerns of employers. Method: The risk evaluation was divided into 'acceptable risk' and 'allowable risk' over time from the stage of installation of hydrogen fueling stations, and compared and analyzed with the results of existing studies. Result: Existing studies have been appropriately applied to the risk assessment performed at the stage of installing hydrogen fueling stations. However, possible risks could be found at the operational stage. In other words, it was derived that an evaluation of management risk was also necessary. And through this, it was confirmed that the safety of hydrogen fueling stations was strengthened. Conclusion: The risk assessment that precedes the stage of installing hydrogen fueling stations is appropriate because significant results have been derived from the 'acceptable risk' assessment. However, the operator needs to evaluate the risks that may occur at the operating stage, that is, the 'allowable risks' and prepare countermeasures. Therefore, it is proposed to add management risk assessment items to build and operate safer hydrogen fueling stations.