• Fire Science and Engineering
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• v.33 no.5
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• pp.155-162
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• 2019

In Korea, the relevant laws and regulations for fire safety in buildings have been revised. Since 2011, Performance-based Design has been conducted for large-scale or high-rise buildings. However, the Korea's performance-based design is still at a level where life safety evaluation using fire and evacuation simulation tools is compared with existing methods. Although related studies have been conducted continuously for the mandatory performance-based design, the fact that it is relatively unsatisfactory for design and construction of fire-fighting facilities as it mainly focuses on administrative and institutional improvement measures or computer simulation. This study collected 91 performance-based design documents that were carried out nationwide at the initial stage of implementation until 2016 to analyze the status of performance-based design of fire-fighting facilities. As a result, fire-fighting facilities, except for fire extinguish system facilities, were not properly designed for performance. Furthermore, the designers found that if corresponding facilities or higher-level equipment with upgraded performance is additionally installed, the performance-based design fared well compared to the existing the prescriptive-based design.

• Applied Chemistry for Engineering
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• v.34 no.4
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• pp.388-396
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• 2023

The evaluation of fire risk for combustible materials was carried out using Chung's equations-X, Chung's equations-XI, and Chung's equation-XII, which were newly established. The fire risk index-XII (FRI-XII) and fire risk rating (FRR) were calculated for specimens including camphor tree, cherry, rubber tree, and elm. The combustion characteristics were determined using a cone calorimeter according to ISO 5660-1. Chung's equations caculated the fire performance index-X (FPI-X) and fire growth index-X (FGI-X) values ranged from 89.34 to 1696.75 s² /kW and from 0.0006 to 0.0107 kW/s² , respectively. In addition, the fire performance index-XI (FPI-XI) and fire growth index-XI (FGI-XI) varied from 0.08 to 1.48 and from 0.67 to 11.89, respectively. The fire risk index-XII (FRI-XII), which is an indicator of fire risk, showed that camphor tree had a value of 148.63 (fire risk rating: G), indicating a very high fire risk. This suggests that combustible materials with a high concentration of volatile organic compounds have lower FPI-X and FPI-XI values, higher FGI-X and FGI-XI values, and consequently higher FRI-XII values, indicating an increased fire risk.

• Journal of the Korean Geotechnical Society
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• v.34 no.2
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• pp.43-54
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• 2018

Underwater tracked vehicle is employed to perform underwater heavy works on saturated seafloor. When an underwater tracked vehicle travels on the seafloor, shearing action and ground settlement take place on the soil-track interface, which develops the soil thrust and soil resistance, respectively, and they restrict the tractive performance of an underwater tracked vehicle. Thus, unlike the paved road, underwater tracked vehicle performance does not solely rely on its engine thrust, but also on the soil-track interaction. This paper aimed at evaluating the tractive performance of an underwater tracked vehicle with respect to ground conditions (soil type, and relative density or consistency) and vehicle conditions (weight of vehicle, and geometry of track system), based on the soil-track interaction theory. The results showed that sandy ground and silty sandy ground generally provide sufficient tractions for an underwater tracked vehicle whereas tractive performance is very much restricted on clayey ground, especially for a heavy-weighted underwater tracked vehicle. Thus, it is concluded that an underwater tracked vehicle needs additional equipment to enhance the tractive performance on the clayey ground.

• Fire Science and Engineering
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• v.26 no.6
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• pp.38-44
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• 2012

The purpose of fire protection for the nuclear power plants (NPPs) is to ensure safe shutdown state of the reactor, to minimize the release of radioactive materials to the environment, to provide physical safety of the on-site personnel, and to limit the property damage. Fire protection and extinguishing equipments are one of the important protection measures based on the defense-in-depth concept, which can promptly detect and control and extinguish those fires that do occur, thereby limiting fire damage. However, a separate evaluation process might be additionally necessary for the construction permit and operating license because the fire protection laws of the NEMA for installation standards of the fire protection systems is not fully characterized for the NPPs. It is also not easy to implement the regulations such as the performance based design concept for fire protection system of the NPPs which are characterized for a relatively low density of employee. This study suggests a guideline for the improvement of the technical standards for fire protection systems of the NPPs by evaluating the fundamental problems drawn by reviewing laws and regulatory guides relevant to fire protection and by evaluating the applicability of the KEPIC FPN in domestic nuclear power plants.

• Journal of Conservation Science
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• v.30 no.3
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• pp.299-306
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• 2014

The possibility of a low-temperature argon plasma treatment as a mean of restoration technology for contaminated invaluable archive materials and artefacts, and evidencing documents was investigated along with an oxygen plasma treatment for comparison. For this purpose, the degree of color changes, ${\Delta}E^*ab$, and surface morphological changes due to plasma treatments as an evaluation of removal performance of artificial contaminants such as brilliant green dye and carbon deposit on cellulose acetate and plain paper as matrices, respectively, were measured and analyzed using a spectrophotometer and a field emission scanning electron microscope. Compared to the argon plasma treatment with sputtering characteristic, that of the oxygen plasma with characteristic of an oxidation reaction has shown superior results in removing the contaminants; the oxygen plasma has proven to damage the matrices significantly due to its oxidative characteristic, and post-plasma reactions has anticipated to be also detrimental to the surfaces, whereas, the problems caused by the counterpart has resulted in being negligible and rather has thought to be an appropriate mean for delicate restoration and/or removal operations of contaminants.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.7
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• pp.4626-4633
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• 2014

The research is being conducted on a SFT (Submerged Floating Tunnel), because of increased exchange among nations and abnormal weather-disasters and new transportation infrastructure has attracted interest. However, studies in this are almost in the early stages around the world and various researches will be needed to promote the safety form the disaster. In this paper, heat transfer analysis was applied among the structural performance evaluation of a SFT if afire occurs in the tunnel. The analysis model of the SFT was performed as steel composite RC hollow. The impact of heat by fire under a range of fire scenarios was analyzed and prevention techniques were examined.

• Journal of Environmental Science International
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• v.30 no.12
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• pp.1053-1065
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• 2021

In this study, the prediction technology of Hydrological Quantitative Precipitation Forecast (HQPF) was improved by optimizing the weather predictors used as input data for machine learning. Results comparison was conducted using bias and Root Mean Square Error (RMSE), which are predictive accuracy verification indicators, based on the heavy rain case on August 21, 2021. By comparing the rainfall simulated using the improved HQPF and the observed accumulated rainfall, it was revealed that all HQPFs (conventional HQPF and improved HQPF 1 and HQPF 2) showed a decrease in rainfall as the lead time increased for the entire grid region. Hence, the difference from the observed rainfall increased. In the accumulated rainfall evaluation due to the reduction of input factors, compared to the existing HQPF, improved HQPF 1 and 2 predicted a larger accumulated rainfall. Furthermore, HQPF 2 used the lowest number of input factors and simulated more accumulated rainfall than that projected by conventional HQPF and HQPF 1. By improving the performance of conventional machine learning despite using lesser variables, the preprocessing period and model execution time can be reduced, thereby contributing to model optimization. As an additional advanced method of HQPF 1 and 2 mentioned above, a simulated analysis of the Local ENsemble prediction System (LENS) ensemble member and low pressure, one of the observed meteorological factors, was analyzed. Based on the results of this study, if we select for the positively performing ensemble members based on the heavy rain characteristics of Korea or apply additional weights differently for each ensemble member, the prediction accuracy is expected to increase.

• Fire Science and Engineering
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• v.33 no.2
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• pp.63-67
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• 2019

In this study, the pressure loss of a fire hose reel hydrant was examined and the effects of each factor on the pressure loss were analyzed. First, in the pressure loss experiment according to the length of the reel hose, the pressure loss increased with increasing length of the reel hose; it was approximately 38.86% based on a 25 m hose. Second, the pressure loss of the reel hose per unit length was estimated to be $.13{\sim}.15kgf/cm^2$. Third, in the pressure loss experiment according to the change in the flow rate, the result was similar to the relation, flow rate - pressure loss (${\Delta}P{\sim}Q^2$), in the piping flow. These results provide basic data on the evaluation of fire pump pressure and the performance-based fire-protecting design of fire hose reel hydrants used in buildings.

• Journal of the Korean Geosynthetics Society
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• v.19 no.1
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• pp.55-63
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• 2020

In this study, a scaled model test of the shaking table and a seismic analysis considering effective stresses were performed to reveal the dynamic behavior characteristics of box structures deep located in multi-layered soils upon seismic loading. The input seismic wave was operated below the ground using five seismic waves, including long period wave (Hachinohe), short period wave (Ofunato), artificial wave and real earthquakes that occurred in Gyeong-ju and Po-hang. As a result of model test and numerical analysis, the vertical displacement of box structures upon seismic loading was greater than that of horizontal direction, and it was confirmed that an increase of excess pore water pressure below the foundation ground caused a displacement. In addition, behavior of the ground and structures during artificial seismic wave appeared to be larger than real earthquake wave.

• Fire Science and Engineering
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• v.34 no.3
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• pp.18-27
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• 2020

An actual fire test was performed on single combustibles placed in a local cinema complex, and quantitative differences in the maximum heat release rate (HRR) and fire growth rate were investigated based on the design fire curve methods (i.e., the general and 2-stage methods). In terms of combustible use and fire load, a total of 12 combustibles were selected, classified into cinema lounge and movie theater. It was found that the maximum HRR and fire growth rate determined using the two-stage method were quantitatively different from those of the general method. The application of the two-stage method, which can be used to determine the fire growth rate of the initial fire stage more precisely, could be useful in accurately predicting the activation time of fire detectors and fire-extinguishing facilities, as well as the available safe egress time (ASET) and required safe egress time (RSET).