• 제목/요약/키워드: fire pattern

검색결과 335건 처리시간 0.021초

Analysis of Fire Suppression Efficiency for Intermittent Water Spray Pattern by Fire Dynamics Simulator (FDS를 이용한 교번식 미분무방식의 소화 성능 분석)

  • Jee, Moon-Hak;Lee, Byung-Kon
    • Fire Science and Engineering
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    • 제22권3호
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    • pp.216-220
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    • 2008
  • Water mist fire suppression system utilizes the fire suppression features such as cooling of fire source, dilution of ambient oxygen, and shielding of radiation heat with the evaporation of microscopic water droplets. The momentum of water mist is relatively lower than that of larger water droplet and the infiltration of water mist to the fire source is not effective. Contribution of evaporated water vapor is liable to decline to limited portion of fire source due to its light weight and sparse density. On the other hand, the cycling water mist pattern is expected to improve the penetration force of water mist as well as the air expelling capability with the stratified spray characteristics. At this paper, we present the analyzed fire suppression capability of intermittent water spray pattern by use of FDS which is computational fire dynamics fire model. We expect this analysis can support the basic concept to the development of the prototype of water mist nozzle.

Ecological resilience of soil oribatid mite communities after the fire disturbance

  • Kim, Ji Won;Jung, Chuleui
    • Journal of Ecology and Environment
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    • 제36권2호
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    • pp.117-123
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    • 2013
  • This study investigated the impact of the fire disturbance and the pattern of recovery of soil dwelling oribatid mite communities with respect to the resilience from the fire disturbance. Oribatid mites are important decomposer animals of plant debris in soil with the feeding habits of saprophagy and mycophagy. Massive wild fire reduced soil oribatid mite abundance and diversity. The impact varied relative to the intensity of the disturbance. The proportion of the species common to the non-disturbed natural site increased as the time after the disturbance elapsed, which implying some degree of naturalness occurring in reorganization phase of the oribatid mite community. From the sites with different degree of fire impact, we found higher diversity in intermediately disturbed sites than in severely disturbed or non-disturbed site, supporting the intermediate disturbance hypothesis. Also this study showed that with differential degree of disturbance plots, resilience pattern after the disturbance can be explored even with shorter period research relative to the ecological succession of community.

An Evaluation Model for Fire Performance (사격효과측정 모델연구)

  • Han, Kyu-Chill
    • Journal of the military operations research society of Korea
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    • 제3권1호
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    • pp.97-107
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    • 1977
  • This report examines several models, such as random or area bombardment, salvo fire and pattern fire, for the computation of target coverage when multiple rounds are fired at a target. Fractional kill of a fragment sensitive target by a fragmenting projectile as a function of the number of rounds fired is compared for two salvo fire models. The first is a standard salvo fire model in which N rounds are fired at the same aim point, in the second model single kill probability is computed for a fragment sensitive target and then fractional kill from the firing of N rounds is computed according to the assumption that the effects of each round are independent. Because the method of solution becomes very laborious for large patterns, this report gives a method only for the case of evaluating the effectiveness of stick and trianglar pattern fire. The need for the sophisticated and complicated target coverage models is demonstrated by the results of computations performed in this report.

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Flame and Carbonization Patterns of Animal-Origin Foods Ignited by Overheating (과열에 의해 발화된 동물성 식품의 화염 및 탄화 패턴에 관한 연구)

  • Lee, Jeong-Hun;Choi, Chung-Seog
    • Fire Science and Engineering
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    • 제33권6호
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    • pp.126-131
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    • 2019
  • Real-scale fire tests were performed on animal-origin foods using a gas stove with no overheating prevention device. When the animal-origin foods were ignited, a large quantity of white smoke and steam was generated from them; however, when they became dry and began to carbonize, a dark smoke was generated. Even after the gas stove was overheated for more than 5400 s, mackerel, pollack, chicken, etc., did not ignite. However, pork, beef, and tuna caught fire after 2643 s, 2819 s, and 6492 s of heating, respectively. The flame patterns of animal-origin foods were in the forms of a mixed laminar flow and a turbulent flow, and a halo pattern was produced. A sand glass form of the flame pattern was generated when a kitchen hood was operated, but a triangular flame pattern was produced when the kitchen hood was not operated. When the tuna in the pot was overheated, it spontaneously ignited after 6492 s, with the surface temperature of the kitchen hood rapidly rising to 464.5 ℃. Moreover, the temperature at the back of the pot, which was 6 cm away from the outer surface of the upper part of the pot, was 869 ℃ after 6660 s because of the radiant heat. The flame formed a sand glass pattern on the kitchen wall. When the kitchen hood was not operated, or when the flame grew lower than the height of the ceiling, a triangular pattern was formed.

A Study on Improvement of Fire Service Deployment Standard in Korea (한국 소방력배치 기준의 개선에 관한 연구)

  • Lee, Hae-Pyeong;Back, Min-Ho
    • Fire Science and Engineering
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    • 제20권1호
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    • pp.28-42
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    • 2006
  • The purpose of this study is to offer the improvement for deployment of fire service force in Korea by settlement patterns on the basis of analysis for the present standard and deployment of fire service force. For the adequate deployment and operation of fire service force by settlement patterns, we carried out the analysis of the present standard calculated with allocation of the authorized strength. We also classified clusters for settlement pattern through the statistical methods. We proposed the standard for deployment of fire service force reflected with environmental and need factors through the introduction of standardized index.

Development of Standardized Predictive Models for Traditional Korean Medical Diagnostic Pattern Identification in Stroke Subjects: A Hospital-based Multi-center Trial

  • Jung, Woo-Sang;Cho, Seung-Yeon;Park, Seong-Uk;Moon, Sang-Kwan;Park, Jung-Mi;Ko, Chang-Nam;Cho, Ki-Ho;Kwon, Seungwon
    • The Journal of Korean Medicine
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    • 제40권4호
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    • pp.49-60
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    • 2019
  • Objectives: To develop a standardized diagnostic pattern identification equation for stroke patients, our group conducted a study to derive the predictive logistic equations. However, the sample size was relatively small. In the current study, we aimed to derive new predictive logistic equations for each diagnostic pattern using an expanded number of subjects. Methods: This study was a hospital-based multi-center trial recruited stroke patients within 30 days of symptom onset. Patients' general information, and the variables related to diagnostic pattern identification were measured. The diagnostic pattern of each patient was identified independently by two Korean Medicine Doctors. To derive a predictive model for pattern identification, binary logistic regression analysis was applied. Results: Among the 1,251 patients, 385 patients (30.8%) had the Fire Heat Pattern, 460 patients (36.8%) the Phlegm Dampness Pattern, 212 patients (16.9%) the Qi Deficiency Pattern, and 194 patients (15.5%) the Yin Deficiency Pattern. After the regression analysis, the predictive logistic equations for each pattern were determined. Conclusion: The predictive equations for Fire Heat, Phlegm Dampness, Qi Deficiency, and Yin Deficiency would be useful to determine individual stroke patients' pattern identification in the clinical setting. However, further studies using objective measurements are necessary to validate these data.

Study on Mechanistic Pattern Identification of Disease for NaeGyungPyen of DongEuiBoGam ("동의보감(東醫寶鑑)" 내경편(內景編)에 나타난 질병(疾病)의 병기론적(病機論的) 변증(辨證)화 연구 - 정신기혈(精神氣血)을 중심으로 -)

  • Kim, Yeong-Mok
    • Journal of Physiology & Pathology in Korean Medicine
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    • 제24권2호
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    • pp.177-186
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    • 2010
  • This study is about researching DongEuiBoGam by analysing with pattern identification of modern Traditional Korean medical patholgy as more logical, systematic and standardized theory. Disease pattern mechanisms of essence, spirit, qi and blood in NaeGyungPyeb of DongEuiBoGam are these. In Essence, this explain mechanism of disease patterns those are seminal emission, dream emission, spermatorrhea, white ooze. These disease pattern's mechanisms are kidney yang deficiency, kidney yin deficiency, heart yang deficiency, heart yin deficiency, heart qi deficiency, spleen qi deficiency and so on. On viewpoints of viscera and bowels they are related with heart, kidney, spleen. And most of them are deficiency from deficiency-excess Pattern Identification. Classifying disease pattern of qi is about upward, downward movement and more concentrated deficiency than excess pattern. Fright palpitations can be classified heart deficiency with timidity, heart blood and qi deficiency, heart qi deficiency, heart blood deficiency, heart qi movement stagnation, water qi intimidating the heart, phlegm-fire harassing the heart, phlegm clouding the pericardium, and so on. Palpitations can be classified heart blood deficiency, heart yin deficiency, heart deficiency with timidity, heart spleen blood deficiency, spleen qi deficiency, phlegm-fire harassing the heart, intense heart fire, and so on. Forgetfulness can be classified heart spleen blood deficiency, heart spleen qi deficiency, kidney essence deficiency, heart qi deficiency, non-interaction between the heart and kidney, etc. for deficiency pattern, phlegm clouding the pericardium for excess pattern. In Blood just say inside bleeding pattern's category, there are nose bleeding, flopping syncope, qi counterflow, blood vomiting, hemoptysis, spitting of blood, bloody stool, hematuria, and so on. Like these, this study identify pattern of disease in DongEuiBoGam by mechanism of disease theory.

Examination on Fire Extinguishing Performance of Full Cone and Hollow Cone Twin-fluid Atomizers: Effects of Supply Gas and Water Mist (중실원추형 및 중공원추형 2유체 미립화기의 화재 소화 성능 검토: 공급 기체와 미분무 영향)

  • Kim, Dong Hwan;Lee, Chi Young
    • Fire Science and Engineering
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    • 제33권5호
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    • pp.28-36
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    • 2019
  • In the present study, the effects of supply gas and water mist on the heptane pool fire extinguishing performance were investigated using the full cone and hollow cone twin-fluid atomizers. Air or nitrogen of 30 lpm (Liter per minute; L/min) was used as the supply gas, and the experiments were conducted under the water flow rate conditions of 0 lpm (i.e., discharge of air or nitrogen only) and 0.085 lpm (i.e., discharge of water mist with supply gas). Experimental results confirmed that the use of water mist discharge with the supply gas and full cone spray pattern reduced the fire extinguishing time as compared to that of only supply gas discharge and hollow cone spray pattern. In addition, for the discharge of water mist using the full cone twin-fluid atomizer, water mist significantly affected fire extinguishing performance, whereas the effect of the supply gas was less pronounced. On the other hand, for the discharge of water mist using the hollow cone twin-fluid atomizer, the fire extinguishing time was remarkably reduced by the supply of nitrogen, as compared with that of air, indicating that the supply gas as well as water mist can significantly affect fire extinguishing performance.

A Literature Study on the Combination of acupoints of HANGYEOK and YEOLGYEOK in the Saam Acupuncture Method (사암침법 한격과 열격의 경혈구성에 관한 고찰)

  • Yu, Jun-Sang;Han, Suzy;Yun, Dong Won
    • The Journal of Korean Medicine
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    • 제41권3호
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    • pp.81-97
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    • 2020
  • Objectives: The objective of this study is to review the methods of combining acupoints of HANGYEOK(Cooling Mode) and YEOLGYEOK(Heating Mode) in Saam Acupuncture Method. Methods: We searched and investigated the journals and literatures by OASIS(Korea Institute of Oriental Medicine) and relevant searching engines with the key word "Saam, Hangyeok, Yeolgyeok". Unfortunately there was no relevant articles on this theme except six literatures. Six literatures with the key words relevant to Saam and acupuncture were selected and analyzed according to each composition of acupuncture prescription especially focusing on HANGYEOK and YEOLGYEOK. Results: Analyzing HANGYEOK and YEOLGYEOK of 12 meridians, two different methods emerged. In HANGYEOK to treat Heat Pattern, one method is to tonify Water points and directly sedate Fire points. The other is also to tonify Water point, but sedate Earth points instead of Fire points. It is assumed that Earth sedation method is to eradicate the underlying Fire. In only Heart meridian and Pericardium meridian there is one method to treat Heat Pattern: Water tonification and Fire Sedation. In YEOLGYEOK to treat Cold Pattern, there is one method to tonify Fire points and sedate Water points. In Pericardium meridian and Triple Energizer meridian there are some different combination of acupoints depending on literatures. Conclusions: Considering HANGYEOK and YEOLGYEOK in Saam Acupuncture Method, two methods are mainly discussed in HANGYEOK; Water Tonification Fire Sedation and Water Tonification Earth Sedation. To remove the underlying Fire, it is regarded that Water Tonification Earth Sedation is appropriate and close to Saam's thought.

A Study on the Arson Fire Characteristics based on Domestic Fire Statistics and Computer Simulation (국내화재통계 및 컴퓨터 시뮬레이션에 의한 방화화재 특성에 관한 연구)

  • Choi, Jin;Kang, Kyung-Sik
    • Journal of the Korea Safety Management & Science
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    • 제10권1호
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    • pp.1-10
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    • 2008
  • With the development of the Korean economy, the number of arson fire has been radically increased and become a huge problem and issue in Korea Society for last several decades. This study is to establish the fire life safety strategy regarding the arson fire through researching domestic fire statistics and performing the computer simulation based on fire scenarios with cutting edge techniques and methods for fire characteristics and fire dynamic. In addition, to design the fire life safety strategy depending on the arson fire pattern, the flow and characteristics of fire flames and smoke are analyzed by the computer modeling.