• Fire Science and Engineering
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• v.12 no.2
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• pp.29-42
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• 1998

The use of computer supported fire safety engineering calculations has grown significantly in recent years and will be increased rapidly. In this study, in order to examine for fire dynamics of the enclosed compartment with window glass(3mm, 4mm thickness) when the window glass breaks, we conducted numerical computer simulations about foam sofa fire with the zone type computer mode, FASTLite package(version 1.1.2) and the Berkeley algorithm for breaking window glass in a compartment fire, BREAK1 program (version 1.0). The analysis of the results in this paper shows that there are differences of fire dynamics between open-or enclosed-state compartment fire and the enclosed compartment fire with window glass breaking. It is also shown in this study that backdraft phenomenum occurs due to accumulated unburned combustible fuel when the glass of 4mm thickness breaks, and that temperature differences between the inner-and outer-surfaces of 3mm and 4mm thick glasses are appreciable. This study will help fire fighter to establish fire suppression or occupant's refuge strategies and fire safety engineer to enhance simulation techniques about the five dynamics of compartment fire.

• Fire Science and Engineering
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• v.27 no.3
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• pp.20-29
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• 2013

To investigate numerically the effects of geometry and location of vertical opening on the thermal and chemical fire characteristics in full-scale under-ventilated compartment fires, the ventilation factor ($A\sqrt{h}$) to estimate a theoretical maximum inflow of ambient air and the mass loss rate in a heptane pool fire were fixed for all cases. It was shown that variations in door geometry affected significantly the change in thermal and chemical characteristics inside the compartment. Variations in window location resulted in the complex change in additional fire characteristics including the fire duration time and recirculating flow structure. These results were analyzed in details by the multi-dimensional flow and fire characteristics including the vent flow and fuel/air mixing phenomena.

• Fire Science and Engineering
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• v.14 no.3
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• pp.27-32
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• 2000

The assessment of wildland fire hazard is the first priority to be considered in the prevention, extinction and control of wildland fire. For the standard to measure wildland fire hazard, the wildland fire Warning System is currently being used in Korea which computes the wildland fire occurrence hazard index through a stick weight to moisture conversion formula. It shows the risk of fuel substance being exposed to fire by meteorological factors. For a comprehensive assessment of wildland fire hazards by area, the major factors'hazards need to be measured and the assessment of wildland fire needs to be conducted through historical statistic examination. Therefore, the wildland (ire outbreak frequency and its seriousness of damage are analyzed through historical statistic examination to conduct the assessment of a wildland fire hazard, and then the calorific value of a forest is analyzed through differential scanning calorimeter measurement which assesses the comparative calorific hazard according to the geographical distribution of vegetation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.600-606
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• 2018

A class D fire or combustible metal fire is characterized by the presence of burning metals. Only certain metals or metal compounds are flammable, including sodium and lithium. General fire extinguishing agents, such as dry chemical powder, water-based fire extinguish agents, and carbon dioxide, cannot be used in class D fires. This is because these agents cause adverse reactions or are ineffective. In addition, the amount of usage of combustible metals is increasing due to continuous development of the semiconductor and fuel cell industries. Despite this, Korea does not have standards and laws related to combustible metal fires. This paper suggests directions of the class D fire management policies to reduce the class D fire risk and impact by analyzing the standards and laws related to class D fires and combustible metal fire cases. The factors to make laws on class D fire prevention and response systems, and management system of dry sand were determined. These results may be used to help reduce the risk of class D fires and improve the response abilities.

• 한국연소학회:학술대회논문집
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• 2014.11a
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• pp.141-142
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• 2014

This numerical study was carried out to optimize dual fuel combustion on natural gas-diesel in static chamber. Spray experiments conducted under conditions of premixed methan 0%, 5% and 10%. In the results, penetration decreases when premixed methane is increasing. Constants of numerical models were acquired from results of spray experiments to enhance accuracy of numerical study. And dual fuel engine simulation was implemented by using AVL-FIRE with acquired constants.

• Proceedings of the KSRS Conference
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• v.1
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• pp.297-300
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• 2006

The knowledge of fuel load and composition is important for planning and managing the fire hazard and risk. However, fuel mapping is extremely difficult because fuel properties vary at spatial scales, change depending on the seasonal situations and are affected by the surrounding environment. Remote sensing has potential of reduction the uncertainty in mapping fuels and offers the best approach for improving our abilities. This paper compared the results of object-oriented classification to a pixel-based classification for fuel type map derived from Hyperion hyperspectral data that could be enable to provide this information and allow a differentiation of material due to their typical spectra. Our methodological approach for fuel type map is characterized by the result of the spectral mixture analysis (SMA) that can used to model the spectral variability in multi- or hyperspectral images and to relate the results to the physical abundance of surface constitutes represented by the spectral endmembers. Object-oriented approach was based on segment based endmember selection, while pixel-based method used standard SMA. To validate and compare, we used true-color high resolution orthoimagery

• Journal of Advanced Marine Engineering and Technology
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• v.28 no.7
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• pp.1123-1130
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• 2004

Numerical simulations have been carried out to investigate the effect of nozzle hole geometry on the combustion characteristics of the large diesel engine. 6S90MC-C. Spray and combustion phenomena were examined numerically using FIRE code. Wane breakup and Zeldovich models were adopted to describe the atomization characteristics and NOx formation processes. Predictions on the cylinder peak pressure and NOx emission were first verified with the experimental data to confirm the reliability of numerical calculations. The comparison results showed good agreements within the range of 0.64% and 4.6% respectively. Finally, the effects of fuel spray angle and diameter on the engine performance were investigated numerically to find the optimum nozzle hole geometry considering fuel consumption, NOx emission and heat flux of the combustion chamber wall. It was concluded that the combustion gas recirculation in cylinder by changing fuel injection direction is an effective method to reduce NOx emission by about 10% with increasing fuel oil consumption, 1.4% in a large diesel engine.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.7
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• pp.1702-1708
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• 1995

Owing to the serious problem of hydrocarbon fuel such as environmental pollution, the development of alternative fuel is very urgent. To adopt hydrogen to the internal combustion engine, a solenoid-drive type in-cylinder injection system was constructed. The injection system was installed to the single cylinder research engine, and the engine performance and the emission of citric oxide were tested upon the fuel-air equivalence ratio and the spark timing. In the case of in-cylinder injection system, hydrogen is injected after the intake valve is close, so it is possible to operate the engine without the back fire and the fall of its volumetric efficiency. In the region of the fuel-air equivalence ratio below 0.5, hydrogen and air aren't well mixed and the thermal efficiency is lowered, so the nozzle should be designed to inject hydrogen uniformly into the combustion chamber. In the region of the fuel-air equivalence ratio above 0.7,the fuel-air mixture burns very fast and the amount of citric oxide emission increases rapidly, so the spark timing should be retarded as compared with MBT.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.20 no.3
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• pp.365-369
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• 2022

Operating and decommissioning nuclear power plants generates radioactive waste. This radioactive waste can be categorized into several different levels, for example, low, intermediate, and high, according to the regulations. Currently, low and intermediate-level waste are stored in conventional 200-liter drums to be disposed. However, in Korea, the disposal of intermediate-level radioactive waste is virtually impossible as there are no available facilities. Furthermore, large-sized intermediate-level radioactive waste, such as reactor internals from decommissioning, need to be segmented into smaller sizes so they can be adequately stored in the conventional drums. This segmentation process requires additional costs and also produces secondary waste. Therefore, this paper suggests repurposing the no-longer-used spent nuclear fuel casks. The casks are larger in size than the conventional drums, thus requiring less segmentation of waste. Furthermore, the safety requirements of the spent nuclear fuel casks are severer than those of the drums. Hence, repurposed spent nuclear fuel casks could better address potential risks such as dropping, submerging, or a fire. In addition, the spent nuclear fuel casks need to be disposed in compliance with the regulations for low level radioactive waste. This cost may be avoided by repurposing the casks.

• Journal of Forest and Environmental Science
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• v.39 no.4
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• pp.235-245
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• 2023

Forest fuel moisture content is a crucial factor influencing the combustion rate and fuel consumption during forest fires, significantly impacting the occurrence and spread of wildfires. In this study, meteorological data were gathered using a meteorological measuring device (HOBO data logger) installed in the south and north slopes of Kangwon National University Forest, as well as on bare land outside the forest, from November 1, 2021, to October 31, 2022. The objective was to analyze the relationship between meteorological data and fuel moisture content. Fuel moisture content from the ground cover on the south and north slopes was collected. Fallen leaves on the ground were utilized, with a focus on broad-leaved trees (Prunus serrulata, Quercus dentata, Quercus mongolica, and Castanea crenata) and coniferous trees (Pinus densiflora and Pinus koraiensis), categorized by species. Additionally, correlation analysis with fuel moisture content was conducted using temperature (average, maximum, and minimum), humidity (average, minimum), illuminance (average, maximum, and minimum), and wind speed (average, maximum, and minimum) data collected by meteorological measuring devices in the study area. The results indicated a significant correlation between meteorological factors such as temperature, humidity, illuminance, and wind speed, and the moisture content of fuels. Notably, exceptions were observed for the moisture content of the on the north slope and that of the ground cover of Prunus serrulata and Castanea crenata.