• Journal of the Korean Society of Safety
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• v.32 no.3
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• pp.112-116
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• 2017

This study applied risk indexes to the disaster flow event occurred at Mt. Umyeon region in 2011. A 2D hydrodynamic model was employed to calculate flow characteristics, and the model was validated against two dam break flow problems conducted by Bellos and EU CADAM project. The model performance was shown to be satisfactory. In order to determine which index is more appropriate to assess the vulnerability of debris flow, 3 risk indexes (FII, FHR and VDI) were considered. It was found that VDI, which determines the risk level only by the velocity factor, consistently predicted the risk level corresponding to 6 because the velocity range was widely organized. However, in the case of FII and FHR, the risk was reasonably quantified due to combined consideration of significant factors of flow velocity and debris thickness. Therefore, FII and FHR are expected to be more accurate than VDI. However, two indexes still need to be improved to include major factors such as debris density or material properties.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.444-455
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• 2009

Great concerns on geotechnical risk & hazard assessment have been increased due to human and economic damage by natural disasters with recent global climate changes. In this paper, geotechnical problems in particular, landslides which is interested in European countries and North America, were mainly discussed. For these, 18 key topics on geotechnical risk and hazards which had been discussed at the LARAM 2008 workshop in Italy were analyzed after grouping by subjects. Main topic contents consisted of applications such as field measurement, early warning systems, uncertainty analysis of parameters using radar, optical data and statistical theory and so on. And the problems related to analysis of vulnerability and deformation due to earthquakes, investigation of gas zone using seismic reflection data in a landslide area, risk quantification and hazard assessment of landslide movements and multi-dimensional analysis for stability of complex slopes were attracted. Also, there were studies on risk matters of cultural heritage, the blockglide of clayey ground, simulations of debris flows based on GIS, quantification of the failure processes of rock slopes, a meshless method for 3D crack modelling, and finally risk assessment for cryological processes due to global warming.

• Wind and Structures
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• v.37 no.4
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• pp.275-287
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• 2023

Subgrade differential settlement of high-speed railways was a pivotal issue that could increase the risk of trains operation. The risk will be further increased when trains in the subsidence zone are affected by crosswinds. In this paper, the computational fluid dynamics (CFD) model and finite element (FE) model were established, and the data transmission interface of the two models was established by fluid-solid interaction (FSI) method to form a systematic crosswind-train-track-subgrade dynamic model. The risk of high-speed train encountering crosswind in settlement area was analyzed. The results showed that the aerodynamic force of the trains increased significantly with the increase in crosswind speed. The aerodynamic force of the trains could reach 125.14 kN, significantly increasing the risk of derailment and overturning. Considering the influence of crosswind, the risk of train operation could be greatly increased. The safety indices and the wheel-rail force both increased with the increase of the wind speed. For the high-speed train running at 350 km/h, the warning value of wind speed was 10.2 m /s under the condition of subgrade settlement with wavelength of 20 m and amplitude of 15 mm.

• Fire Science and Engineering
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• v.14 no.4
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• pp.7-16
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• 2000

In the study, three criteria(toxicity, fire & explosion, environment) and damage prediction method for each case was set up, and all these criteria were applied to the subject substance that was selected as hazardous level by integrating all criteria through Algorithm. Particularly, the environment criterion is a comprehensive concept, environment index modeling by combining USCG(United State Coast Guard) & MSDS(Material Safety Data Sheet) environment criteria classifications and the environment part of MFPA's health hazardousnes(Nh). And for damage prediction method of each criterion were adopted and they were applied to hazardous chemical substances in use or stored by chemical substance related enterprises located in each region that made possible to set up total hazard level of used substances(inflammability, poisonousness and counteraction on a unit substance, and hazard level & display modeling on environment) & damage prediction in case of accident & solidity setup(CPQRA: Chemical Process Quantitative Risk Assessment, IAEA: International Atomic Energy Agency, VZ eq: Vulnerable Zone) risk counter. Thus it is deemed that it can be applied to toxic substance leakage that can happen during any chemical processing & storage, application as a tool for prior safety evaluation through potential dangerousness computation of fire & explosion.

• Journal of Veterinary Science
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• v.25 no.3
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• pp.41.1-41.12
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• 2024

Importance: Equines are indispensable in reducing the huge burden on children and women and income generation. On the other hand, minimal attention is given to improving their health and welfare. Objective: This study examined the prevalence and associated risk factors of helminth parasites of equine in the Gamo Gofa Zone. Methods: A cross-sectional study was employed from June 2019 to March 2020. The study districts and Kebeles were selected purposively based on agroecology whereas selection of study households and animals were performed based on simple random sampling techniques. Identification of nematode, trematode parasite ova and larvae of D. arnfieldi were done by floatation, sedimentation, and Baermann techniques respectively. Descriptive statistics and logistic regression was applied to estimate the prevalence and association of risk factors with helminth parasites. Results: The overall helminth parasite prevalence in the study area was 90.4%, 425/470 (95% [CI], 87.16-92.9). The prevalence of Strongyle, Fasciola, O. equi, P. equorum, D. arnfieldi, and mixed parasite infections were 65.1%, 21.7%, 17.4%, 34%, 34%, and 58.1%, respectively. Infections from Fasciola species and D. arnfieldi infection were four ([AOR], 4.4; 95% CI, 2-9.4) and two times (AOR, 2; 95% CI, 1.1-3.6) respectively more likely occur in donkeys than in mules. The occurrence of Strongyle species in midland agroecology was two times (AOR, 2.6; 95% CI, 1.4-4.7) more likely than lowland agroecology. Conclusions and Relevance: The present study identified diverse species of equine helminth parasites that necessitate urgent disease control and prevention measures.

• Journal of the Korean Institute of Gas
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• v.24 no.3
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• pp.27-32
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• 2020

For preventing accident, the risk analysis about gas facilities has been more important since many gas facilities be superannuated. Especially, deriving and simulating risk is very important for preventing and corresponding accidents by means of specific analysis method in complex gas facilities. However, many studies have been not enough not yet in order to derive and simulate risk considering various situations. This paper aims to propose deriving and analyzing risk method around limited area of complex gas facilities. Our study proposes total risk analysis that is composed four methods with individual point of view. The risk analysis system based on RiskMAP immediately informs users changes of e risk in zones according to the status, work and surrounding conditions of the facility. The proposed methods in this research are implemented as software algorithm and applied to risk analysis system using RiskMAP in conjunction with IoT and GPS.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.1
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• pp.478-484
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• 2013

Recently, the risk of safety accidents in the coastal zone has been increased due to revitalization of marine leisure and tourism. Because of a lack of regulations about technical and maintenance aspect for safety facilities, the effective measures to prevent safety accidents in the coastal zone have not taken with increasing rate of the accidents. The nature of land/sea and behavioral characteristics of a fisherman/port laborer/tourist/people at leisure should be taken into account properly when safety facilities to prevent safety accidents in the coastal zone are installed, since the characteristics of land/sea and many activities such as fishery, harbor works, tour, leisure are mixed in the geographic and environmental condition of the coastal zone. This study analyzes the current problems on the safety facility in the domestic coastal zone through the domestic and foreign(Hongkong, Macau) field survey. Also the direction of the improvement about the safety facility are proposed.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.955-962
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• 2008

This study concerns the effect of drainage in reinforced soil on its stability during rainfall. A series of finite-element analysis based transient seepage analysis were performed on a number of cases with different drainage conditions in terms of layers of geotextiles installed in the reinforced zone. The results were then coupled with the limit-equilibrium slope stability analysis to investigate the variation of global stability factor of safety with rainfall infiltration into the reinforced wall. The results were thoroughly analyzed to get insight into the mechanism of pore water pressure reduction effect of the geotextile and into its effect on overall slope stability. It is shown that layers of geotextile installed in the reinforced zone can prevent decrease in suction in the reinforced zone during rainfall, thereby reducing potential risk of decreasing shear strength of the reinforced zone. Practical implications of the findings were discussed.

• Journal of the Society of Naval Architects of Korea
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• v.61 no.2
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• pp.106-114
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• 2024

In the 21st century, the rapid development of automation and artificial intelligence technologies is driving innovative changes in various industrial sectors. In the transportation industry, this is evident with the commercialization of autonomous vehicles. Moreover research into autonomous navigation technologies is actively underway in the aviation and maritime sectors. Consequently, for the practical implementation of autonomous ships, an effective collision avoidance algorithm has become a crucial element. Therefore, this study proposes a collision avoidance algorithm based on the Obstacle Zone by Target(OZT), which visually represents areas with a high likelihood of collisions with other ships or obstacles. The A-star algorithm was utilized to represent obstacles on a grid and assess collision risks. Subsequently, a collision avoidance algorithm was developed that performs fuzzy control based on calculated waypoints, allowing the vessel to return to its original course after avoiding the collision. Finally, the validity of the proposed algorithm was verified through collision avoidance simulations in various encounter scenarios.

• Journal of Conservation Science
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• v.37 no.5
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• pp.505-515
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• 2021

In this study, we evaluated the slope stability of the Pohang Daljeon-ri columnar joint (Natural Monuments # 415) and calculated the maximum energy, jumping height and moving distance of rockfalls using a simulation. Based on the results, we established the range of rockfall risk. The slopes of the Pohang Daljeon-ri columnar joint have dip directions of 93.79°, 131.99°, 165.54° and 259.84° from left (SW) to right (NE). Furthermore, they have a fan-like shape. The Pohang Daljeon-ri columnar joints are divided into four sections depending on the dip direction. The measurement results of the discontinuous face show that zone 1 is 125, zone 2 is 261, zone 3 is 262, zone 4 is 43. The results of slope stability analyses for each section using a stereographic projection method correspond to the range of planar and toppling failure. Although it is difficult to diagnose the type of failure, risk evaluation of currently falling rocks requires further focus. The maximum movement distance of a rockfall in the simulation was approximately 66 m and the rockfall risk range was the entire area under slope. In addition, it is difficult to forecast where a rock will fall as it rolls in various directions due to topographic factors. Thus, the installation of measures to prevent falling is suggested to secure the stability based on the results of the rockfall simulations and its probabilistic analysis.