• Advances in Computational Design
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• v.1 no.1
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• pp.105-117
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• 2016

The objective of this work is to study the restraining effect in fire resistance of framed structures and to evaluate the global response of reinforced concrete frames when exposed to fire based on advanced finite element method. To study the response a single portal frame is analyzed. The effect of floor slab on this frame is studied by modeling a beam-column-slab assembly. The evolution of temperature distribution, internal stresses and deformations of the frame subjected to ISO 834 standard fire curve for both the frames are studied. The thermal and structural responses are evaluated and a comparison of results of individual members and entire structure is done. From the study it can be seen that restraining forces has significant influence on both stresses and deflection and overall response of the structure when compared to individual structural member. Among the various structural elements, columns are the critical members in fire and failure of column causes the failure of entire structure. The fire rating of various structural elements of the frame is determined by various failure criteria and is compared with IS456 2000 tabulated fire rating.

• Journal of the Korean Society of Propulsion Engineers
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• v.14 no.5
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• pp.24-31
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• 2010

Combustion-stability rating of impinging-jet injector is conducted numerically using hot-fire simulation in a subscale chamber with the five-element injector head. A sample F(fuel)-O(dxidizer)-O-F impinging-jet injector is adopted. In this work, instantaneous chemical reaction is adopted for hot-fire simulation based on the assumption that mixing process of fuel and oxidizer streams is controlling. The model chamber was designed based on the methodologies proposed in the previous work regarding geometrical dimensions and operating conditions. The present stability boundaries are in a good agreement with air-injection and hot-fire experimental data. The proposed numerical method can be applied cost-effectively to stability rating of jet injectors when mixing of fuel and oxidizer jets is the dominant process in instability triggering.

• Journal of the Korea institute for structural maintenance and inspection
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• v.11 no.2
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• pp.109-116
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• 2007

The purpose of this paper is to evaluate the fire resistant performances of load-bearing wall using both composite and steel stud panel infilled with light-weight formed mortar under axial loading according to KS F 2257(1999). The minimum requirement of 2 hours fire resistant rating is needed for the residential and commercial buildings under the fire regulation of Korea. From test results, it is found that two types of specimen composed of the hybrid stud and steel stud panel filled with light-weight formed mortar fited in with the requirement of 2 hours fire resisting rate for the load-bearing wall. In the conclusions, the specimen with hybrid stud shows predominating fire-resistant performance on the adiabatic effects rather than that of the steel stud specimen.

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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• 2005.09a
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• pp.119-124
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• 2005

• Journal of the Korean Ceramic Society
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• v.52 no.4
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• pp.253-263
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• 2015

Ordinary Portland cement is a widely favored construction material because of its good strength and durability and its reasonable price; however, spalling behaviour during fire exposure can be a serious risk that can lead to strength degradation or collapse of a building. Geopolymers, which can be synthesized by mixing aluminosilicate source materials such as metakaolin and fly ash, and alkali activators, are resistant to fire. Because the chemical composition of geopolymers controls the properties of the geopolyers, geopolymers with various Si:Al ratios were synthesized and evaluated as fire resistant construction materials. Rejected fly ash generated from a power plant was quantitatively analyzed and mixed with alkali activators to produce geopolymers having Si:Al ratios of 1.5, 2.0, and 3.5. Compressive strength of the geopolymers was measured at 28 days before and after heating at $900^{\circ}C$. Geopolymers having an Si:Al ratio of 1.5 presented the best fire resistance, with a 44% increase of strength from 29 MPa to 41 MPa after heating. This material also showed the least expansion-shrinkage characteristics. Geopolymer mortar developed no spalling and presented more than a 2 h fire resistance rating at $1,050^{\circ}C$ during the fire testing, with a cold side temperature of $74^{\circ}C$. Geopolymers have high potential as a fire resistant construction material in terms of their increased strength after exposure to fire.

• Journal of Korea Society of Industrial Information Systems
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• v.18 no.5
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• pp.81-92
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• 2013

The satellite includes many release mechanisms such as solar array deployment, antenna deployment, cover to protect contamination in scientific equipment, pyro value of the propulsion subsytem, and bypass device in Li-Ion cell module. A drive the initiators is a critical to the successful mission because the initiators of release mechanism driving by the pyrotechnic circuit is operated in single short. The pyrotechnic circuit has to provide switching network for safety. A typical switching network has defect consisting of high current rating fire switch to handle switching transient current during fire the initiator. The pyrotechnic circuit is required some form of power conditioning to reduce the peak power demanded from the bus if the initiators are to be fired from the main bus. This paper design a pyrotechnic circuit synchronized to the fire-command to activate the fire switch to overcome use high current rating fire switch to handle switching transient current during fire the initiator. The pyrotechnic circuit provides a current limited widow pulse for fire current synchronized to the fire-command to insure that fire switch will only carry the current but never switch it. The current limited widow pulse for fire current can be possible to use low current rating and light mass switch in switching network. The current limit function in the pyrotechnic circuit reduces supply voltage to initiator and provides the effect of power conditioning function to reduce peak bus power. The pyrotechnic circuit to apply satellite development on geostationary orbit is verified the function by test in development model.

• Journal of Korean Society of Forest Science
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• v.95 no.2
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• pp.160-167
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• 2006

Most of the forest fires that occur in South Korea are caused by human. We partitioned South Korea into nine districts and used observed weather data and daily fire occurrence records for the 1994 to 2003 period to develop a human-caused fire occurrence model of South Korea. Logistic regression analysis techniques were used to relate the probability of a fire day to Fine Fuel Moisture Code (FFMC) component of the Canadian Forest Fire Danger Rating System. The probability of the number of fire day was increased as FFMC increased in the nine districts of South Korea.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 1998.11a
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• pp.73-76
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• 1998

To use glazing systems protected by automatic sprinklers as fire barriers in building compartmentation, fire endurance tests of these systems have been performed by several research workers. Most of the tests concerned the types of glasses and sprinklers, sprinkler water flow rate, and sprinkler activation time. Horizontal side wall sprinklers and window glazing systems with a vertical center mullion were mainly applied in the tests. In the study, full-scale fire endurance tests were carried out to verify the ability of large glazing systems divided by a horizontal mullion and protected by pendent vertical sprinklers. The result shows that the protrusive length of the horizontal mullion, which is perpendicular to the glass surface, is the main parameter that determines the fire resistance rating of the systems. The mullion obstructs the water flow in the glass.

• Korean Journal of Agricultural and Forest Meteorology
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• v.14 no.1
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• pp.1-10
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• 2012

Digital Forecast of the Korea Meteorological Administration (KMA) represents 5 km gridded weather forecast over the Korean Peninsula and the surrounding oceanic regions in Korean territory. Digital Forecast provides 12 weather forecast elements such as three-hour interval temperature, sky condition, wind direction, wind speed, relative humidity, wave height, probability of precipitation, 12 hour accumulated rain and snow, as well as daily minimum and maximum temperatures. These forecast elements are updated every three-hour for the next 48 hours regularly. The objective of this study was to construct Forest Fire Danger Rating Systems on the Korean Peninsula (FFDRS_KORP) based on the daily weather index (DWI) and to improve the accuracy using the digital forecast data. We produced the thematic maps of temperature, humidity, and wind speed over the Korean Peninsula to analyze DWI. To calculate DWI of the Korean Peninsula it was applied forest fire occurrence probability model by logistic regression analysis, i.e. $[1+{\exp}\{-(2.494+(0.004{\times}T_{max})-(0.008{\times}EF))\}]^{-1}$. The result of verification test among the real-time observatory data, digital forecast and RDAPS data showed that predicting values of the digital forecast advanced more than those of RDAPS data. The results of the comparison with the average forest fire danger rating index (sampled at 233 administrative districts) and those with the digital weather showed higher relative accuracy than those with the RDAPS data. The coefficient of determination of forest fire danger rating was shown as $R^2$=0.854. There was a difference of 0.5 between the national mean fire danger rating index (70) with the application of the real-time observatory data and that with the digital forecast (70.5).

• Fire Science and Engineering
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• v.15 no.3
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• pp.49-54
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• 2001

Recently, intentional arsons for exploitation and wildland fire caused by abnormal change of weather are increasing as well as the damage scale due to such fire in the world. The number of such big wildland fire is also increasing in Korea these days. Fire prevention activity can be said as more important than fire putting-out activity after a fire occurrence for the most effective way to cope with wildland fire, and the research on wildland fire prevention system is what we need to do urgently, In this study I examined and analyzed the experiments and data about the factors influencing wildland fire and stated the dangerousness of each factor for all of the 6 factors and set up the general dangerousness rating applying each factor's contribution to the dangerousness.