• Journal of Ocean Engineering and Technology
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• v.31 no.3
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• pp.219-226
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• 2017

In this study, the impact characteristics of subsea pipelines that were installed in various soil types and burial depths were evaluated by a numerical method. An impact scenario replicated a dropped ship anchor that fell vertically and impacted an installed subsea pipeline. In order to calculate the impact force through terminal velocity, FLUENT, a computational fluid dynamic program and MDM (Moving Deforming Mesh) technique were applied. Next, a dynamic finite element program, ANSYS Explicit Dynamics, was used for impact analysis between the anchor and pipeline (or, subsea if they were buried). Three soil types were considered: loose sand, dense sand and soft clay by applying the Mohr-coulomb model to the seabed. The buried depth was assumed to be 0 m, 1 m and 2 m. In conclusion, a subsea pipeline was the most stable when buried in dense sand at a depth of 2 m to prevent impact damage.

• Journal of the Korean Institute of Gas
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• v.14 no.5
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• pp.38-44
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• 2010

This treatise analyzed the risk of propylene transported by railroad through quantitative analysis. As a result of survey on propylene transportation route, Iksan station, Suncheon station and Jeonju station were selected as object regions those were expected to have high accident risks. This treatise deduced the scenario of accident and the occurrence rate in accordance with the type of accident possibly to be happening during propylene transportation through ETA( Event Tree Analysis), and expressed the level of personal, social risks after calculating the level of demage influencing over surroundings based on the evaluation for the expected accident damage through PHAST 6.53.

• Fire Science and Engineering
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• v.12 no.1
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• pp.15-21
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• 1998

In this research, we studied reach the conclusion with more probability for predicting the severity which based on fire cases in domestic department stores for last 30 years. Considering the number of yearly fire cases in department stores and the cost of damage, we set the risk level. Moreover, this research shows the severity of fire in department stores through its scenario applying to FPETOOL program which NIST in USA has developed. By the result of FPETOOL program operation, we could acquired information about the time reaching the point where people are in danger in temperature, smoke layer and gas concentration. When a fire breaks out in a department store, a great loss of property and life is significant, as well as the potential risk is awfully considerable. Therefore, we should prevent a five from occuring.

• Journal of the Korean Institute of Gas
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• v.10 no.3 s.32
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• pp.48-53
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• 2006

In case of fire and explosion which resulted from LP gas release of LPG vessel retail store, the populated area such as apartment complex is supposed to be damaged either partially or totally. To estimate the damage of LP gas explosion, we conducted quantitative risk analysis procedure as has been recommended by AIChE/CCPS. For incident scenario selection, event tree analysis was proposed. TNT equivalent method, SAFER Trace v.8.0 and probit model were also used for consequence analysis. The various methods and analyses which were performed in this study are presented with the effect zones in the layout.

• Korean Journal of Environmental Biology
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• v.37 no.3
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• pp.268-277
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• 2019

Severe damages will result in human society, when several different critical natural phenomena coincide. One example relates to the resting cysts of Alexandrium species (dinoflagellates that cause paralytic shellfish poisoning), which are preserved in surface sediments throughout Osaka Bay, Japan. These cysts have been found to accumulate particularly densely in shallow areas in the inner parts of Osaka Bay, where a tsunami caused by an earthquake could occur any time. Damage by a tsunami could cause a change of the coastal ecosystems at Osaka Bay including the resuspension of surface sediments containing resting Alexandrium tamarense cysts and the subsequent redistribution of the cysts in newly deposited sediment. Under certain environmental conditions, these cysts could germinate and form dense blooms, leading to paralytic shellfish poisoning. Such a scenario could also affect other coastal areas, including the southern coast of the Korean Peninsula.

• Computers and Concrete
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• v.17 no.2
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• pp.201-214
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• 2016

The outer tank of a liquefied natural gas (LNG) storage tank is a longitudinally and meridianally pre-stressed concrete (PSC) wall structure. Because of the current trend of constructing larger LNG storage tanks, the pre-stressing forces required to increase wall strength must be significantly increased. Because of the increase in tank sizes and pre-stressing forces, an extreme loading scenario such as a bomb blast or an airplane crash needs to be investigated. Therefore, in this study, the blast resistance performance of LNG storage tanks was analyzed by conducting a blast simulation to investigate the safety of larger LNG storage tanks. Test data validation for a blast simulation of reinforced concrete panels was performed using a specific FEM code, LS-DYNA, prior to a full-scale blast simulation of the outer tank of a 270,000-kL LNG storage tank. Another objective of this study was to evaluate the safety and serviceability of an LNG storage tank with respect to varying amounts of explosive charge. The results of this study can be used as basic data for the design and safety evaluation of PSC LNG storage tanks.

• Advances in aircraft and spacecraft science
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• v.7 no.1
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• pp.1-17
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• 2020

In this paper, a new model-based Fault Detection and Diagnosis (FDD) method for an agile supersonic flight vehicle is presented. A nonlinear model, controlled by a classical closed loop controller and proportional navigation guidance in interception scenario, describes the behavior of the vehicle. The proposed FDD method employs the Inertial Navigation System (INS) data and nonlinear dynamic model of the vehicle to inform fins damage to the controller before leading to an undesired performance or mission failure. Broken, burnt, unactuated or not opened control surfaces cause a drastic change in aerodynamic coefficients and consequently in the dynamic model. Therefore, in addition to the changes in the control forces and moments, system dynamics will change too, leading to the failure detection process being encountered with difficulty. To this purpose, an equivalent aerodynamic model is proposed to express the dynamics of the vehicle, and the health of each fin is monitored by the value of a parameter which is estimated using an adaptive robust filter. The proposed method detects and isolates fins damages in a few seconds with good accuracy.

• Journal of Environmental Science International
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• v.21 no.12
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• pp.1503-1510
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• 2012

The purpose of this article is analyzing the impacts of climate change on red pepper yield in Korea, with employing a panel data regression model. Our results show that there is a negative impacts of high temperature and precipitation amount on red pepper yields. Especially high temperature and rainfall in July cause serious damage to red pepper yield. According to the reduction schedule on greenhouse gas emission(RCP 8.5 scenario.), red pepper yield would be 25.4% lower than it is, for reasons of high temperature and rainfall damages by the end of 21st century.

• Steel and Composite Structures
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• v.21 no.3
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• pp.479-500
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• 2016

Seismic design criteria allow enhancing the structural ductility and controlling the damage distribution. Therefore, detailing rules and design requirements given by current seismic codes might be also beneficial to improve the structural robustness. In this paper a comprehensive parametric study devoted to quantifying the effectiveness of seismic detailing for steel Moment Resisting Frames (MRF) in limiting the progressive collapse under column loss scenarios is presented and discussed. The overall structural performance was analysed through nonlinear static and dynamic analyses. With this regard the following cases were examined: (i) MRF structures designed for wind actions according to Eurocode 1; (ii) MRF structures designed for seismic actions according to Eurocode 8. The investigated parameters were (i) the number of storeys; (ii) the interstorey height; (iii) the span length; (iv) the building plan layout; and (v) the column loss scenario. Results show that structures designed according to capacity design principles are less robust than wind designed ones, provided that the connections have the same capacity threshold in both cases. In addition, the numerical outcomes show that both the number of elements above the removed column and stiffness of beams are the key parameters in arresting progressive collapse.

• Fire Science and Engineering
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• v.22 no.1
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• pp.76-83
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• 2008

In the subway fire case, it is important that judge accuracy subway fire type and on the initial response minimize accident damage. But when the subway fire accident occurring, if it have know impossible that accuracy subway fire type to judge at once though witnessing driver or emergency response staff. This study suggests type of five senses that using information of five sense take to the subway fire accident information which analyses five senses as occurring subway fire accident. Also it is proposed that emergency response system though fire scenario by using Activity-Action Diagram(AAD).