• Title/Summary/Keyword: Fail-Safety

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The Effectiveness of the Dispersant Use during the "Deepwater Horizon" Incident -REVIEW of the Proceedings from 2011 International Oil Spill Conference- (미국 멕시코만 기름유출사고에서 본 유처리제 사용의 효용성 고찰)

  • Cho, Hyun-Jin;Ha, Chang-Woo
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.18 no.1
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    • pp.61-65
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    • 2012
  • Once oil has spilled, oil spill responders use a variety of countermeasures to reduce the adverse effects of spilled oil on the environment. Mechanical methods of containment and recovery are preferred as the first response when the use of other methods fail or are ineffective. In these cases, the application of oil dispersants shall be use only as a last resort. While effectiveness of dispersants in removing oil form the sea surface is proven, the use of dispersants is controlled in almost all countries due to the toxicity of their active agents and the dispersed oil on the marine environment. However, according to reports, after dispersant application, no significant toxicity to fish or shrimp was observed in the field-collected samples. Moreover, the results also indicate that dispersant-oil mixtures are generally no more toxic to the aquatic test species than oil alone. During the Deepwater Horizon Incident, dispersants were applied to floating oil and injected into the oil plume at depth. These decisions were carefully considered by state and federal agencies, as well as BP, to prevent as much oil as possible from reaching sensitive shoreline habitats. Net Environmental Benefit Analysis for dispersant use assumed that dispersants appear to prevent long-term contamination resulting absence of oil in the substrate and will benefit marine wildlife by decreasing the risk of significant contamination to feathers or fur. Further study to use dispersants with scientific baseline is needed for our maritime environment which consistently threaten huge oil spill incidents occurrence.

Cost-Benefit Analysis Method for Ageing Equipment of Chemical Plants Using Risk Assessment (위험성평가를 이용한 노후설비에 대한 비용 편익분석 방법)

  • Jung, Soomin;Jung, Changmo;Kang, Seok-Min;Chae, Seungbeen;Kang, Seung-Gyun;Ko, Jae Wook
    • Journal of the Korean Institute of Gas
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    • v.24 no.4
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    • pp.84-92
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    • 2020
  • Most facilities in chemical plants operate in environments that are outside the range of temperature and pressure that can be encountered on a daily basis, and are vulnerable to aging due to these stresses and environmental conditions. The facilities exposed to these conditions are not only likely to fail due to cumulative damage, but also lead to accidents if maintenance and replacement are not performed.Recommendation guidelines called risk-based inspection are widely used around the world-wide. However, limits exist for facilities that have already elapsed for a certain. As a result of the survey on the aging of Ulsan industrial complex in Korea, which carries out proper inspection, many of the facilities have been used for 20 years. Also, most of the facilities where the accident occurred have been in operation for more than 20 years. Therefore, this study suggested criteria for classifying devices that have exceeded a certain period of use as obsolete facilities. In addition, quantitative risk assessment was conducted. The safety investment method using the cost-benefit analysis method was proposed in order to calculate the loss cost and reduce the risk by expressing the risks of the corresponding aged facility as an Economic index. By utilizing the method of cost-benefit analysis of old facilities using the quantitative risk assessment presented in this study, it can be expected to improve the performance and life of old facilities, improve production efficiency and reliability of the system of facilities, change the recognition of safety management costs, increase employee stability, and reduce loss costs.

Estimation of R-factor and Seismic Performance for RC IMRFs using N2 Method (N2 Method를 이용한 RC 중간모멘트 연성골조의 반응수정계수 및 내진성능 평가)

  • 윤정배;이철호;최정욱;송진규
    • Journal of the Earthquake Engineering Society of Korea
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    • v.6 no.6
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    • pp.33-39
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    • 2002
  • Response Modification Factor(R-factor) approach is currently implemented to reflect inelastic ductile behavior of the structures and to reduce elastic spectral demands from earthquakes to the design level. However R factors were set empirically and simply based on the professional committee consensus on observed performance of building structures during past earthquakes. Consequently some major shortcomings linked to the current R factor approach have been pointed out. Using reinforced concrete intermediate moment-resisting frames(RC IMRFs), an analytical procedure is presented in this paper to establish R factor rationally. To this end, analytical R values were evaluated based on N2 Method and compared with the values recommended by IBC 2000. Overall, the analytical results correlated well with the code values. However the results also revealed that R factor might strongly depend on the system fundamental period. As evidenced by the interstory drift index(IDI) analysis results of this study, current R-factor based(or, Life Safety based) design tends to fail in fulfilling other implicit and hopeful performance objectives such as immediate Occupancy and Collapse Prevention. Performance based design(PBD) appears to be a promising approach to meet the multi level seismic performance objectives assigned to the building structures of nowadays.

Effects of the LOHAS Image of Restaurants on Involvement and Willingness to Pay (레스토랑의 로하스 이미지가 관여도 및 지불의사에 미치는 영향)

  • Kim, Na-Hyung
    • The Journal of the Korea Contents Association
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    • v.16 no.1
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    • pp.666-675
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    • 2016
  • With the changing consciousness of consumers, there has been an increasing interest in nature-friendly lifestyles and safety of food ingredients. Therefore, the LOHAS image, which has value in social health and sustainability, is expected to be a factor that helps restaurants establish differentiation strategies. This study examined the LOHAS image of restaurants on involvement and willingness to pay. The results were as follows. First, eco-friendly food ingredients and interiors among the LOHAS image factors of restaurants had a significant effect on involvement. Second, the perception of LOHAS in the LOHAS image factors of restaurants had a significant effect on involvement. These results may be due to the lack of a conceptual understanding of LOHAS among restaurant customers, who fail to properly grasp its meaning. Therefore, in order to promote the LOHAS image of restaurants to customers, it is necessary to consider presenting POPs or signs that will enable customers to understand the concept of LOHAS inside the restaurant. Third, consumers' involvement turned out to have a significant effect on their willingness to pay. Thus, it is necessary to imprint the image of a LOHAS restaurant using eco-friendly colors, sculptures, and agricultural products so that customers can perceive food ingredients or interior elements as eco-friendly.

Analysis of Aircraft Upset through TEM and Improvement of UPRT (항공기 비정상 자세 사고의 TEM 분류 및 UPRT 향상에 관한 연구)

  • Choi, Jin-Kook;Jeon, Seung-Joon
    • The Journal of the Korea Contents Association
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    • v.19 no.11
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    • pp.365-374
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    • 2019
  • Loss of Control in Flight(LOC-I) due to aircraft upset attitude has the highest air accident rate, and International Aviation Institute such as ICAO and FAA recommended flight crew to operate aircraft safely through UPRT(Upset Prevention & Recovery Training) program. ICAO has selected Loss of Control(LOC) as key safety indicator, and recommended to respond using TEM(Threat and Error Management). However there are not much specific treats and errors classified for UPRT programs using real TEM based on evidences. This study intends to consider the importance of UPRT through the introduction of UPRT and accident analysis using TEM. Typical upset accidents were classified to common threats as IFR, inadequate training, Automation surprise, and inexperienced copilots. The common errors were cross-check, speed and altitude deviation, callouts, communication, thrust and stall action fail. The undesired aircraft states were inadequate automation mode, Deviation of speed and vertical, stall, and crash. These suggest areas to improve UPRT.

A Study on Response Characteristics of Photoelectric Type Smoke Detector Chamber Due to Dust Color (분진색상에 따른 광전식연기감지기 챔버의 응답특성에 관한 연구)

  • Lee, Ho-Sung;Kim, Si-Kuk
    • Fire Science and Engineering
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    • v.31 no.5
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    • pp.44-52
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    • 2017
  • This paper is based on a study of the response characteristics of photoelectric type smoke detector chambers according to dust color. Due to an amendment to the Fire Safety Codes to automatic fire alarm systems and visual alarm device, the installation of indoor smoke detectors has become mandatory, but in Korea there is still insufficient research on the non-operation or false alarms that could arise in indoor environments by indoor dust and other environmental conditions etc. In light of this, for this study, research was conducted on the indoor adaptability of smoke detector under various colors of fiber dust that were judged to occur most frequently in among the common indoor dust, photoelectric smoke detector with the lattice-type smoke detection chamber that the smoke detector which is most popular in the country was used, and four colors of fiber dust (brown, white, gray and black) were used the test dusts for carrying out dust and sensitivity testing. Also, the voltage of the photocell part of the smoke chamber was measured, and the scattering phenomenon in the chamber was observed. The result of the testing showed that all four dust types were suitable for dust and sensitivity testing under conditions of pollution A. Yet, there were occasions, at pollution B or C, where the brown, white and gray dust would cause fail alarm during operation testing. And black dust was confirmed to cause non-operation during operation testing. In the case of brown and white dust, the voltage measurement result of the photocell part of the smoke chamber confirmed that the voltage increases as the pollution level increases, and in the case of gray and black dust, the voltage decreases.

Heat Transfer Modeling by the Contact Condition and the Hole Distance for A-KRS Vertical Disposal (A-KRS 수직 처분공 접촉 조건 및 처분공 간의 거리에 따른 열전달 해석)

  • Kim, Dae-Young;Kim, Seung-Hyun
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.17 no.3
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    • pp.313-319
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    • 2019
  • The A-KRS (Advanced Korean Reference Disposal System) is the disposal concept for pyroprocessed waste, which has been developed by the Korea Atomic Energy Research Institute. In this disposal concept, the amount of high-level radioactive waste is minimized using pyrochemical process, called pyroprocessing. The produced pyroprocessed waste is then solidified in the form of monazite ceramic. The final product of ceramic wastes will be disposed of in a deep geological repository. By the way, the decay heat is generated due to the radioactive decay of fission products and raises the temperature of buffer materials in the near field of radioactive waste repository. However, the buffer temperature must be kept below $100^{\circ}C$ according to the safety regulation. Usually, the temperature can be controlled by variation of the canister interdistance. However, KAERI has modelled thermal analysis under the boundary condition, where the waste canisters are in direct contact with each other. Therefore, a reliable temperature analysis in the disposal system may fail because of unknown thermal resistence values caused by the spatial gap between waste canisters. In the present work, we have performed thermal analyses considering the gap between heating elements and canisters at the beginning of canister loading into the radioactive waste repository. All thermal analyses were performed using the COMSOL software package.

Preliminary Feasibility Study for Water Resources Policy Effect Analysis Direction (수자원분야 예비타당성 조사 정책효과 분석 방향)

  • Seong, Yeonjeong;Choi, Seungan;Kwon, Hyun-Han;Jung, Younghun
    • Journal of Korean Society of Disaster and Security
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    • v.14 no.3
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    • pp.1-16
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    • 2021
  • Recently, large-scale projects are required in the water resources sector considering safety and publicitythe due to uncertainty of securing water resources and changes in the ecological environment by climate change. Among these large-scale projects, the projects that fall under the preliminary feasibility study are determined by comprehensive analysis based on economic analysis, policy analysis, and balanced regional development analysis. However, most of the results of the preliminary feasibility study showed a tendency to depend heavily on economic analysis. For this reason, projects in non-metropolitan areas sometimes fail in the preliminary feasibility study. To supplement this point, the Korea Development Institute revised the standard guidelines for preliminary feasibility studies for water resources sector projects that place a high weight on policy feasibility analysis. Therefore, the objective of this study is to analyze the cases of the preliminary feasibility study conducted previously and to suggest the direction of policy analysis in the preliminary feasibility study for water resources sector projects. For this, we analyze preliminary feasibility studies conducted for 18 years from 2002 to 2019, and suggest direction of policy analysis method using the benefit items not included in the economic analysis.

Analysis of Failure Behavior of Piles Embedded in Liquefied Soil Deposits (액상화 지반에 근입된 말뚝의 파괴거동 분석)

  • Cho, Chong-Suck;Han, Jin-Tae;Hwang, Jae-Ik;Park, Young-Ho;Kim, Myoung-Mo
    • Journal of the Korean Geotechnical Society
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    • v.22 no.11
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    • pp.123-131
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    • 2006
  • Liquefaction-induced lateral spreading has been the most extensive damage to pile foundations during earthquakes. Several cases of pile failures were reported despite the fact that a large margin of safety factor was employed in their design. In this study, 1-g shaking table tests were performed in order to analyze the failure behavior of piles embedded in liquefied soil deposits by buckling instability. As a result, it can be concluded that the pile subjected to excessive axial loads $(near\;P_{cr})$ can fail easily by buckling instability during liquefaction. When lateral spreading took place in sloping grounds, it was found that lateral loading due to lateral spreading increased lateral deflection of pile and reduced the buckling load. In addition, from the buckling shape of pile, difference between Euler's buckling and pile buckling vat observed. In the case of pile buckling, hinge formed at the middle point of the pile, not at the bottom. And in sloping grounds, location of hinge formation got lower compared with level ground because of the soil movements.

A Study on the Effects of an Increase in the Height of Ship's Accommodation Area on Safe Evacuation in Emergency Situation (선박 거주구역의 높이가 피난안전에 미치는 영향에 대한 연구)

  • Kim, Won-Ouk;Kim, Jong-Su
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.17 no.1
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    • pp.69-73
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    • 2011
  • Unlike land fires, Fires on board a ship are not likely to be extinguished by skilled human resources using a variety of fire fighting equipments, but have to be brought under control on board a ship itself despite of difficult task. There are more cases of deaths from suffocation by smoke than from an increased temperature by heat in fires on board ships, because crew fail to secure a sufficient visibility range enough to escape from the scene of a fire or to leave the ship as early as possible. On the assumption that the height of ship's accommodation area increases from 2.0m to 2.3m comparable to the height of apartments on the ground in Korea, behaviors of fire smokes between the cases of 2.0m and 2.3m heights were compared and analyzed. Based on the blue print of the existing Training Ship "Hanbada", a new blueprint with the 30 cm height adjustment was additionally created. FDS (Fire Dynamic Simulator), which was created by the NIST in the United States and is the most widely distributed simulator for fires, was used to conduct a simulation and predict results. The results of simulation on the basis of temperature of $60^{\circ}C$ showed a safe evacuation period of time at the position 10m apart from the scene of a fire to increase by 55.8 seconds, when the height of ship's accommodation area increased from 2.0m to 2.3m. The results of simulation on the basis of visibility range of 6m showed the safe evacuation periods of time at the positions 10m, 20m and 30m apart from the scene of a fire to increase by 27.1 seconds, 109.2 seconds and 73.3 seconds, respectively, as the height of ship's accommodation area increased from 2.0m to 2.3m. This means that crew can escape more safely from a scene of fires on board when the height of ship's accommodation area is increased and equal to the height of living room in a building on land.