• Journal of the Korean Institute of Gas
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• v.27 no.4
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• pp.12-18
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• 2023

The effective evacuation strategy according to the accident scenario is crucial to minimize human casualties in the event of toxic gas leak accidents. In this study, the effect of the direction of a building and the location of an industrial complex on the increase in indoor concentration and outdoor diffusion was examined under the same leakage conditions, and effective evacuation criteria were established. In addition, the guidelines for building directions were suggested when constructing buildings that would mitigate human damage caused by chemical accidents. Three scenarios where buildings faced the front, side, and rear of the leakage direction were investigated through CFD simulations. The results revealed that when the building faced the industrial complex, both indoor and outdoor average gas concentrations increased significantly, reaching up to 120 times higher than the other two orientations. Moreover, the indoor space was filled with toxic gas substances more than twice in the same time due to the rapid increase of indoor concentration rate. In cases where the building's windows were positioned at the front, toxic gas stagnation occurred around the building due to pressure differences and reduced flow velocities. Based on our findings, the implementation of these guidelines will contribute to safeguarding residents by minimizing exposure to toxic gas during chemical accidents.

• Korean Journal of Organic Agriculture
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• v.32 no.2
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• pp.233-245
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• 2024

In a field study, we investigated the consequences associated with the irrigation of red pepper with water contaminated by three types of veterinary antibiotics (amoxicillin, oxytetracycline, and chlortetracycline) on the soil residue, the absorption-translocation, and crop yields. As a result of evaluating the residue of veterinary antibiotics in pepper cultivation soil treated with veterinary antibiotics a total of 7 times from June 7 to August 26, 2023, the three antibiotics were not detected at the background level, but in the group treated with 10-fold and 50-fold of the background level was detected at a level of 2-10 ㎍/kg. For the leaf (stem) and fruit of red pepper, all three types of veterinary antibiotics were found to be below the detection limit at all treatments. However, trace levels were detected in red pepper roots. If veterinary antibiotics are unintentionally introduced into agricultural soil in the short term, the soil environment and crop safety will not be a problem. However, long-term introduction of veterinary antibiotics in agricultural soil may have negative effects by affecting soil microbial diversity and antibiotic resistance problems, so continuous monitoring and risk assessment are deemed necessary.

• Culinary science and hospitality research
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• v.15 no.4
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• pp.1-8
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• 2009

The aim of this study is to investigate the microbial contamination assessment of raw Jinmichae to cook and to establish its control. Three kinds of Korean Jinmichae products(K1, K2, K3) and three kinds of imported Jinmichae products(Chile: F1, Peru: F2, Mexico: F3) were collected from markets and department stores in Seoul and Gyeonggi-do. The results were as follows; Aerobic mesophilic bacteria in raw Jinmichae(F2) was detected $7.20{\times}10^7$ CFU/g, which exceeded the acceptable standard level, $1.0{\times}10^6$ CFU/g. The rest of raw groups fell up to $1.0{\times}10^3{\sim}1.0{\times}10^4$ CFU/g. Aerobic mesophilic bacteria were detected in blanched and fried Jinmichae groups. Boiled Jinmichae group did not exceed the acceptable standard level of $1.0{\times}10^6$ CFU/g. However, all the fried groups exceeded the level. E. coli were detected in raw Jinmichae but it was able to be controlled by blanching. Unlike this, E. coli was not completely controlled by roasting for 20 seconds relative to 40, 60 seconds. S. aureus were effectively controlled by boiling, however, it was not controlled by roasting. After roasting Jinmichae for 60 seconds, S. aureus were detected in the half of all groups. In this study, Jinmichae were found to be favorable one of side dishes in school meal service. Jinmichae can be contaminated by microbial pathogens such as S. aureus, E. coli, etc. Therefore, further studies are needed to monitor microbial pathogens and to provide their control.

• Journal of the Korean Geographical Society
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• v.47 no.5
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• pp.755-774
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• 2012

The main objective of the study is to propose GIS-based methods to assess the population distribution criteria for undesirable facilities such as nuclear power plants. First of all, a review of the relevant criteria was conducted for the official documents compiled by such institutions as IAEA (International Atomic Energy Agency), U.S. NRC (Nuclear Regulatory Commission), and some national institutes including the Korea Institute of Nuclear Safety. It is informed from the review that the fundamental principle underlying the various criteria is to maximize the distance between a plant and the nearest population center. It is realized that two interrelated GIS-based techniques need to be devised to put the principle into practice; sophisticated ways of representing population distribution and identifying population centers. A dasymetric areal interpolation is proposed for the former and cell-based and area-based critical density methods are introduced. Grid-based population distributions at various spatial resolutions are created by means of the dasymetric areal interpolation. By applying the critical density methods to the gridded population distribution, some population centers satisfying the population size and density criteria can be identified. These methods were applied to the case of the Gori-1 nuclear power plant and their strengths and limitations were discussed. It was revealed that the assessment results could vary depending upon which method was employed and what values were chosen for various parameters. This study is expected to contribute to foster the applications of methods and techniques developed in geospatial analysis and modeling to the site selection and evaluation.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.5 no.4
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• pp.273-281
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• 2007

Hyperalkaline groundwater formed by groundwater-cement components and its reaction with bedrock in a nuclear waste repository were simulated by geochemical modeling. The result of groundwater-cement components reaction showed that the pH of water was 13.3 and the precipitated minerals were Brucite, Katoite, Calcium Silicate Hydrate(CSH1.1), Ettringite, Hematite, and Portlandite. The result of interaction between such minerals and groundwater sampled in Gyeongju area also showed that the pH of groundwater reached 12.4. Interaction between such hyperalkaline groundwater and granite was simulated by kinetic model during $10^3$ years. This result showed that the final pH of groundwater reached 11.2 and the variation of pH was controlled by dissolution/precipitation of silicate and CSH minerals. Groundwater quality was also determined by dissolution/precipitation of silicate, CSH, oxide minerals. Our results show that geochemical modeling of long-term hyperalkaline groundwater and rock interaction can contribute to the safety assessment of engineered barrier by predicting geochemical condition in repository site.

• Korean Security Journal
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• no.36
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• pp.293-316
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• 2013

Today's high-rise buildings are increasing concern about the safety and evacuation of people related to the fire and threat from outside. Terrorism breaking out in high-rise buildings, a symbol of the national economy results in a number of casualties, economic loss, social fear and damage to national status. That's why high-rise building has also emerged as a target of major terrorist attacks, compared to other types of buildings. We have 54 high-rise buildings in 15 regions over the country. The Ministry of Land, Infrastructure and Transport and Seoul Metropolitan Government have offered the guidelines to prevent terrorist attacks toward high-rise buildings. Since the 9/11 terrorist attacks, the U.S. Federal Emergency Management Agency (FEMA) has developed and taken advantage of the Risk Management Manual Series. According to this manual, pre-assessment is conducted for the prevention of terrorism and particularly in FEMA 455, risk of the surrounding areas, vulnerability, possibility from terrorist attacks are checked. After the check, experts classify the risk of terrorist attacks toward the high-rise buildings and according to the risk classification, architects, security experts and structure engineers can carry out terrorism prevention program for high-rise buildings. The U.K. NaCTSO has also offered the terrorism prevention guidelines. Therefore, the Ministry of Land, Infrastructure and Transport and Seoul Metropolitan Government should make more concrete guidelines for high-rise buildings such as what U.S. FEMA and U.K. NaCTSO implement, including prior evaluation technique for terrorism risk.

• Journal of the Korea Institute of Building Construction
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• v.20 no.2
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• pp.137-145
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• 2020

The recent bridge construction projects demand thorough and systematic safety and risk management, due to the increase of risk factors following the introduction of new and complex construction methods and technologies. Among many types of damages that can occur in bridge construction projects, the damages to third parties who are not directly related to the existing property of the contractor construction project can also bring about critical loss in the project in order to compensate the damages. Therefore, risks that could be caused by the loss occurred to indemnify the third party damages should be clearly analyzed, although there are not subsequent amount of studies focusing on the issue. Based on the past record of insurance payment from domestic insurance companies for bridge construction projects, this study aimed to analyze the risk factors of bridge construction for loss caused to compensate the third-party damages happened in actual bridge construction projects and to develop a quantified and numerical predictive loss model. In order to develop the model, the loss ratio was selected as the dependent variable; and among many analyzed independent variables, the superstructure, foundation, flood, and ranking of contractors were the four significant risk factor variables that affect the loss ratio. The results produced can be used as an essential guidance for balanced risk assessment, supplementing the existing analysis on material losses in bridge construction projects by taking into account the third-party damage and losses.

• Journal of Korean Society of Transportation
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• v.32 no.6
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• pp.579-588
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• 2014

In this study, three signal control strategies such as Bike box, Hook-turn, and 6-phase were assessed for various traffic conditions at signalized intersections incorporating bicycle left-turn traffic. Results showed that the size of a waiting zone mainly affected the performance of signal control in both Bike box and Hook-turn. Both Bike box and Hook-turn yielded an identical vehicle delay, but Bike box produced less bicycle delay than Hook-turn by 2.5~29.9 sec/veh for undersaturated traffic conditions. For saturated traffic condition, Bike box produced less vehicle delay than Hook-turn and 6-phase strategies, but bicycle delay was found to increase at the 700 vph of bicycle traffic compared to 6-phase. Bicycle delay was greatly increased under Hook-turn and Bike box strategies when bicycle traffic was greater than 300 vph and 500 vph, respectively. It was also shown that bicycle delay could be significantly reduced by providing appropriate size of queueing space. In addition, Bike box was likely to yield less vehicle and bicycle delay than Hook-turn for traffic volume patterns investigated in this study.

• Fire Science and Engineering
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• v.31 no.2
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• pp.29-36
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• 2017

The design fire based on the heat release rate (HRR) of combustibles can significantly affect the assessment of fire safety in the performance-based design (PBD). In the present PBD, however, limited information in the foreign literature has been used without further verification due to the lack of fire information in domestic combustibles. The objective of this study is to provide information on the HRR and fire growth rate for various combustibles in residential and office spaces. To end this, the fire experiments were carried out with single and multiple combustibles. The peak HRR of combustibles used in the present study had a range of 36 kW~1,092 kW. The fire growth rates were also $0.003kW/s^2{\sim}0.0287kW/s^2$ and $0.003kW/s^2{\sim}0.0838kW/s^2$ for the residential and office spaces, respectively. In particular, a sofa had the highest fire risk in terms of the peak HRR and fire growth rate. Finally, a methodology for calculating the peak HRR in a space was proposed through correlation analysis between the peak HRR and exposed surface of various combustibles.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.3
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• pp.247-255
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• 2014

Objectives: We reviewed the CAREX (CARcinogen EXposure) program designed to estimate the prevalence of occupational exposure to carcinogens and summarized the advantages and limitations of this program. Methods: All literature, including reports on CAREX and the use of CAREX, were reviewed. The keyword search term was CAREX. Additional articles were identified from references cited in articles and reviewed. Results: An exposure information system, CAREX was developed based on data from the Finnish Institute of Occupational Health of Finland and from the US. CAREX has been applied in several countries, including in the EU, in order to estimate national exposure patterns to carcinogens. The initial exposure assessment carried out through CAREX was aimed at estimating exposures over the period of 1990-1993. To estimate the number of workers exposed to carcinogens by using CAREX, reference exposure prevalence from Finland and the United States was computed, which was then reviewed and corrected by national experts. Finally the overall number of workers exposed to carcinogens can be estimated. We found that CAREX has been used in a total of 18 countries. No Asian country has used CAREX. Conclusions: CAREX can be applied not only to estimate the number of workers exposed to carcinogens in Korea, but also to identify high-risk industries with workers most exposed to carcinogens.