• Title/Summary/Keyword: burned area

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EVALUATION FOR DAMAGED DEGREE OF VEGETATION BY FOREST FIRE USING LIDARAND DIGITALAERIAL PHOTOGRAPH

  • Kwak, Doo-Ahn;Chung, Jin-Won;Lee, Woo-Kyun;Lee, Seung-Ho;Cho, Hyun-Kook;We, Gwang-Jae;Kim, Tae-Min
    • Proceedings of the KSRS Conference
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    • 2007.10a
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    • pp.533-536
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    • 2007
  • The LiDAR data structure has the potential for modeling in three dimensions because the LiDAR data can represent voxels with z value under certain defined conditions. Therefore, it is possible to classify the physical damaged degree of vegetation by forest fire as using the LiDAR data because the physical loss of canopy height and width by forest fire can be relative to an amount of points reached to the ground through the canopy of damaged forest. On the other hand, biological damage of vegetation by forest fire can be explained using the NDVI (Normalized Difference Vegetation Index) which show vegetation vitality. In this study, we graded the damaged degree of vegetation by forest fire in Yangyang-Gun of South Korea using the LiDAR data for physical grading and digital aerial photograph including Red, Green, Blue and Near Infra-Red bands for biological grading. The LiDAR data was classified into 2 classes, of which one was Serious Physical Damaged (SPD) and the other was Light Physical Damaged (LPD) area. The NDVI was also classified into 2 classes which are Serious Biological Damaged (SBD) and Light Biological Damaged (LBD) area respectively. With each 2 classes ofthe LiDAR data and NDVI, the damaged area by forest fire was graded into 4 degrees like damaged class 1,2,3 and 4 grade. As a result of this study, 1 graded area was the broadest and next was the 3 grade. With this result, we could know that the burned area by forest fire in Yangyang-Gun was damaged rather biologically because the NDVI in 1 and 3 grade appeared low value whereas the LiDAR data in 1 and 3 grade included light physical damage like the LPD.

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Am Experimental Study on Measurement of Number Density and Temperature Distributions in $C_3H_8/O_2$ Flame by UV Laser Rayleigh Scattering (UV Laser Rayleigh Scattering을 이용한 $C_3H_8/O_2$ 화염에서 가스 성분의 농도 및 온도 분포 계측에 관한 실험적 연구)

  • Jin, S. H;Nam, G. J.;Kim, H. S.;Chang, N. K.;Park, S. H.;Kim, U.;Park, K. S.;Kim, G. S.
    • Transactions of the Korean Society of Automotive Engineers
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    • v.5 no.2
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    • pp.60-68
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    • 1997
  • Rayleigh Scattering Cross Sections($\sigma$i) of various gases and the temperature distributions of premixes C3H8/O2 flame are measured by high power KrF(248nm) Exci- mer laser and ICCD camera. Results show that $\sigma$i of O2 and Propane(C3H8) gases agree well in the 5% error range, but of H2 has the more or less difference from the calcul- ated value by other groups. This is attributed to the low RS signal of H2 to Nosie level(S/N ratio). The temperature distributions of flame range out between 300K in the air and about 2000K in the burned area. In this temperature range, out system has the about 250K temperature resolution. Because low RS signals in the reaction area with high temperature are affected highly by noises, temperature uncertainty of this area is relatively high to another part of flame. Experimental results show that UV Rayleigh Scattering can be used for the measurement of mixing ratio of mixed gases and the temperature distributions of flame. Especially, this technique can be applied for the measurement of the mixing ratio of air/fuel before the ignition and the flame structure after the ignition inside the Engine.

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The remote-sensing based estimation of the evapotranspiration change due to the 2019 April Gangwon-do wildfire (2019년 강원도 산불로 인한 증발산 변화 원격탐사기반 추산)

  • Kim, JiHyun;Sohn, Soyoung;Kim, Yeonjoo
    • Journal of Korea Water Resources Association
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    • v.52 no.11
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    • pp.941-946
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    • 2019
  • A wildfire could significantly alter the local hydrological regime, depending on the area and severity, and thus it is critical to understand its effect and feedback using data and simulation. For the wildfire in Gangwon-do on April 4-5, 2019, South Korea, we retrieved the Normalized-Burned Ratio (NBR) index using remote-sensing data (500-m 8-day MODIS surface reflectance data), and detect the damaged-area based on the difference in the NBR (dNBR) before and after the fire. The damaged area was $29.50km^2$ in total, taking up 1.00-6.19% of five catchments. We then used remote-sensing data (500-m 8-day MODIS evapotranspiration data) and estimated that annual evapotranspiration (AET) would decrease as 0.05-1.56% over the five catchments, as compared to the pre-fire AET (2004-2018). This study highlights the importance of improving our understanding about the impact of wildfire on the local hydrological cycle.

A Study on Soil Animal in the Forest Fire Area (산불지역의 토양동물에 관한 연구)

  • 손홍인;최성식
    • The Korean Journal of Soil Zoology
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    • v.5 no.2
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    • pp.47-62
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    • 2000
  • This study investigated the effect of soil animals at forest fire area, and it carried out the mountain located at Jundae Ri, Houeng-chen Myen, Ha-dong Gun, Kyoung-Nam Province, southern part of Korea, where burned out about 50 hectars on April 11, 1997. Vegetation of the examined area absolutely dominated with the pines of 7-14 cm in diameter and 20 to 30 years old and the rest were covered with mixed forest with a shrub such as the oak (Quereus mongolia Fisch, Quereus variabilis BI, Quereus dentana Thunb), snowbell(Styrax japonica, S, et, z), lacquer tree (Rhus trichocarpa Mig), azalea (Rhododendron mucronulatum Turcz), etc. And there were simple area organized as a herbaceous plant, and the burnt area was poor experimental sites, where litter layer and herbaceous plant disappeard due to fire, and the unburnt area was rich in surface plant, dead leaves, twigs, etc. But the ground cover vegetations were poor in the unburnt area. The distribution of each animal groups, the seasonal fluctuation in population density, the biomass of meso$.$macroarthropods and the relationship between soil animal and some environmental factors were investigated and analyzed at each experimental area. The result are summarized as follow: 1. Identificated 257,087 individuals of soil microarthropods were classified into 7 classes and 24 orders of Arachinida, Insecta, Chilopoda, Symphyla, Diplopoda, Isopoda and Oligochaeta., and identified 8,006 individuals of the total meso$.$macroarthropods were classified into 7 classes and 20 orders of Arachinida, Insecta, Chilopoda, Symphyla, Diplopoda, Isopoda and Oligochaeta. 2. Among the total soil microarthropods, Arachinida formed 70.9%, followed by Insecta for 28.4% and among the total meso$.$macroarthropod , Insecta formed 57.6%, followed by Chilopoda for 23.8%.

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Preparation of Spherical Granules of Dolomite Kiln Dust as Gas Adsorbent

  • Choi, Young-Hoon;Huh, Jae-Hoon;Lee, Shin-Haeng;Han, Choon;Ahn, Ji-Whan
    • Journal of the Korean Ceramic Society
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    • v.53 no.1
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    • pp.13-17
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    • 2016
  • It is highlighted that increasing the adsorbent surface area on volumetric basis is very important in providing an easy access for gas molecules. Fine particles around $3{\mu}m$ of soft-burned dolomite kiln dust (SB-DKD) were hydrated to wet slurry samples by ball mill process and then placed in a chamber to use spray dryer method. Spherical granules with particle size distribution of $50{\sim}60{\mu}m$ were prepared under the experimental condition with or without addition of a pore-forming agent. The relationship between bead size of the pore-forming agent and size of SB-DKD particles is the most significant factor in preparation of spherical granules with a high porosity. Whereas addition of smaller beads than SB-DKD resulted in almost no change in the surface porosity of spherical granules, addition of larger beads than SB-DKD contributed to obtaining of the particles with both 15 times larger average pore volume and 1 order of magnitude larger porosity. It is considered that spherical granules with improved $N_2$ gas adsorption ability may also be utilized for other atmospheric gas adsorption.

A Study on the Architectural Characteristic of Nam-kwan-wang-myo and it's Reconstruction (고종 36년(1899) 남관왕묘의 중건과 건축 특성 연구)

  • Kwon, Joon-Hyung
    • Journal of architectural history
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    • v.22 no.4
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    • pp.73-82
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    • 2013
  • This study aims to find architectural characteristic of Nam-kwan-wang-myo as known as Nam-myo, Especially focusing on difference between before and after it's reconstruction in 1899. Nam-kwan-wang-myo is a shrine for Kwan-woo who was warlord in ancient china. Belief of Kwan-Woo was introduced to Korea in Japanese invasion of 1592 and the shrine was built in 1598. Belief of Kwan-Woo diffused for the late Joseon, during the reign of Gojong, many people have faith in Kwan-Woo including the king. There was four Kwan-wang-myo around the Hanyang at that time. In 1899 a fire of unknown cause broke out at Nam-kwan-wang-myo, so the main buildings burned down. The king instructed reconstruction of the shrine even though there was in financial difficulties, it had done in the midst of a national crisis. The buildings almost restored as before. The buildings in the shrine has strong characteristics of Chinese architecture because it made by people of the Ming dynasty. Two side-by-side roofs, accumulated brick exterior are important architectural feature, but also all the buildings in the mail hall area Surrounded by the closed-connected fence is hard to find examples in Korea traditional architecture. And Nam-kwan-wang-myo just had maintained architectural characteristics including layout of buildings, shape of the each building until it's reconstruction(1899).

Heat Loss to Combustion Chamber Wall During Laminar Flame Propagation (층류화염전파중의 연소실 벽면으로의 열손실)

  • 이상준;한동호;김문헌;이종태;이성열
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.16 no.7
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    • pp.1398-1407
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    • 1992
  • The prediction of heat loss during laminar flame propagation was carried out by measurement of gas pressure and visualization of flame propagation in the constant volume combustion chamber. And to validate the prediction, the instantaneous temperature at wall of combustion chamber was also measured. Consequently, it was found that heat loss was increased according to increasing of maximum flame travel distance, but rate of heat loss for heat release during laminar flame propagation was nearly constant. And heat loss depends on heat transfer area which was contacted the wall by burned gas regardless to spark plug location.

A Study on the Combustion Characteristics and the Control on the Fuel Flow Rate of LPG Intake Port Injection Engine (흡기포트 분사식 LPG 엔진의 연료량 제어 및 연소 특성에 관한 연구)

  • 김우석;이종화;정창현
    • Transactions of the Korean Society of Automotive Engineers
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    • v.8 no.6
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    • pp.31-39
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    • 2000
  • In this paper, characteristics of a port injection type LPG fuel system were investigated to adopt the system to a spark ignition engine through rig test. Engine combustion characteristics for limited conditions and the precise control method of LPG fuel supply were also studied. As a basic experiment, the effects and the relationships of parameters such as orifice area, fuel delivery pressure, fuel temperature and flow coefficient were established. From this, one dimensional compressible flow equation can be applied to control gaseous fuel flow rate by setting pressure difference between vaporizer and manifold to a certain range, for example about 1.2 bar in a naturally aspirated engine. The combustion analysis results of LPG engine were also compared with those of gasoline engine according to spark timing and load change. At part load and stoichiometric condition, the MBT spark timing of LPG fueled engine is retarded by 2$^{\circ}$ - 4$^{\circ}$CA compared to that of gasoline engine. On the contrary, the spark timing of LPG fueled engine can be advanced by 5$^{\circ}$- 10$^{\circ}$ CA at WOT, which results from higher Octane Number and burned fraction of LPG fuel compared to gasoline.

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A Case of Chemical Burn Caused by Trifluoroacetic Anhydride that Mimicked a Hydrofluoric Acid Burn (불화수소산에 의한 것으로 오인된 Trifluoroacetic anhydride에 의한 화학화상)

  • Park, Jung-Soo;Kim, Hoon;Lee, Suk-Woo
    • Journal of The Korean Society of Clinical Toxicology
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    • v.8 no.1
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    • pp.43-45
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    • 2010
  • A 22-year-old woman was referred to our emergency department for the treatment of a chemical injury on her arm. She had accidentally spilled 99% trifluoroacetic anhydride (TFAA) over her left forearm during an organic chemistry experiment. She visited a primary care unit, and then she was referred to our hospital for inactivation of the released fluoride ions. Her skin lesions were different from those caused by hydrofluoric acid (HF) injury. The injured area showed painful whitish maculae and patchy areas with accentuated rim. No vesiculation and bulla formation was detected. We intradermally injected a 5% solution of calcium through a 24-gauge needle into the burned skin. After the injection, she complained of more severe pain. Although TFAA contains fluorine, it does not release free fluoride ions on contact with the skin, unlike HF. In fact, application of calcium gluconate for TFAA burns is not recommended. Rather, it should be avoided since it increases pain and local abscess formation.

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Thermodynamic Modeling of Heat Loss and Quenching in a Down Scaled Combustor (형상 축소된 연소기의 열손실 및 소염해석 모델)

  • Lee, Dae-Hoon;Kwon, Se-Jin
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.26 no.7
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    • pp.919-926
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    • 2002
  • Down scaled combustor undergoes increased heat loss that results in incomplete combustion or quenching of the flame as a consequence. Therefore, effect of enhanced heat loss should be understood to design a MEMS scale combustion devices. Existing combustion models are inadequate for micro combustors because they were developed for analysis of regular scale combustor where heat loss can be ignored during the flame propagation. In this research a combustion model is proposed in order to estimate the heat loss and predict quenching limit of flame in a down scaled combustor. Heat loss in the burned region is expressed in a convective form as a product of wall surface area, heat transfer coefficient and temperature difference. Comparison to the measurements showed satisfactory agreement of the pressure and temperature drop. Quenching is accounted for by introducing a correlation of quenching parameter and heat loss. The present model predicted burnt fraction of gases with reasonable accuracy and proved to be applicable in thermal design of a micro combustor.