• 제목/요약/키워드: Fire patterns

검색결과 231건 처리시간 0.027초

배선에서의 반단선 및 접촉불량에 대한 열적 전조 DB구축 (Development of Thermal Precursor DB for Partial Disconnection and Poor Contact on Electrical Wire)

  • 김두현;김성철;이종호;강동규
    • 한국안전학회지
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    • 제24권2호
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    • pp.30-36
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    • 2009
  • This paper aims at the precursor analysis and DB development of electrical fires based on thermal and current signals for partial disconnection and poor contact on electric wires through experiments and simulations. Also, DB system required for developing the precursor DB with these data was studied and designed. Firstly, in case of partial disconnection, characteristics were derived and analyzed by experiment and electrical-thermal finite element method(Flux 3D) on the model wires which consist of VCTF and IV electric wires. Based on the characteristics, About 351 partial disconnection precursor patterns were generated by the thermal analysis for electric wire according to deterioration time under normal state and 200% overload state of rated current. Secondly, in order to develop poor contact precursor patterns, temperature value and the current signal were considered. In simulating the poor contact situation on connector area of MCCB, connection torque was changed. Through the experimental analysis, about 251 poor contact precursor patterns were generated. Finally, Using thermal precursor patterns obtained by partial disconnection and poor contact, electrical fire thermal precursor DB was developed.

1990년대와 2000년대 건조계절의 산불발생 시공간 변화 분석 (Spatio-Temporal Analysis of Forest Fire Occurrences during the Dry Season between 1990s and 2000s in South Korea)

  • 원명수;윤석희;구교상;김경하
    • 한국지리정보학회지
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    • 제14권3호
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    • pp.150-162
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    • 2011
  • 우리나라에서는 최근 19년 동안에 연평균 448건의 산불이 발생하였다. 특히, 전체 산불발생건 수의 약 94%가 봄 가을철 건조계절에 동시다발적으로 빈번하게 발생하였다. 이는 국가적인 산림화재의 피해를 최소화하기 위해 산불을 효율적이고 체계적으로 관리하는 것이 필요하다. 본 연구에서는 최근 19년간 발생한 건조계절 산불을 1990년대와 2000년대로 나누어 순기에 따른 각 시군별 산불발생빈도의 시공간적 패턴을 GIS로 분석 후 1990년대 대비 2000년대의 순기별 산불발생빈도 변화 패턴을 비교 분석하였다. 분석 결과 1990년대와 2000년대에는 가장 높은 산불발생빈도를 나타낸 순기가 4월 초순으로 같았지만 이에 대한 지역별 산불발생빈도가 한반도 서쪽인 충청지역을 중심으로 대전에서 27건으로 가장 많이 증가하였고, 호남 및 인천지역에서 10건 이상 증가한 것으로 분석되었다. 그러나 강원 홍천에서는 4월 하순에 최대 12건이 감소한 것으로 나타났다. 본 연구를 통해 시기변화에 따라 이동하는 산불에 대한 지역별 맞춤형 산불방지대책 수립이 가능해질 것으로 판단된다.

『상한론(傷寒論)』 삼음병(三陰病)에 대한 연구(硏究) - 예후 분석을 중심으로 - (A Study on the Three Yin Diseases(三陰病) in the 『Shanghanlun(傷寒論)』 -Focusing on Prognosis Analysis-)

  • 박상균;방정균
    • 대한한의학원전학회지
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    • 제34권1호
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    • pp.47-65
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    • 2021
  • Objectives : An accurate judgment of prognosis when treating diseases is crucial. While the 『Shanghanlun(傷寒論)』 deals with the prognosis of the Three Yin Diseases with great importance, full-scale studies have been lacking. This paper aims to study the Three Yin Diseases with a focus on prognosis analysis. Methods : Among the Three Yin Disease verses, those that could provide clues to prognosis were selected and analysed. Conclusions & Results : When Yang pulse patterns such as long(長脈)·floating(浮脈)·rapid(數脈) pulses and Yang symptoms such as fever, vexing heat, mild perspiration, thirst, warmth in hands and feet are present in Yin disease, it could be taken as signs of Yang Qi restoration. In these situations, Yin Cold pattern such as diarrhea and reversal cold disappear and the prognosis is positive. However, despite Yang pulse patterns and symptoms, there are cases where diarrhea happens as a result of cold dampness being eliminated due to Yang Qi restoration. Also, when Yang Qi starts communicating smoothly after its restoration in the Three Yin Diseases, perspiration can happen. When diarrhea and reversal cold, which are patterns of Yin Cold get worse, with pulse patterns such as unfelt(脈不至)·replete(實脈)·fulminating(脈暴出) pulses, false heat symptoms such as fever and hot flashes happen, accompanied with Yang Qi depleted symptoms such as inability to lie down due to agitation, continuous perspiration, sore throat, dyspnea, and exaggerated breathing happen. When fast pulse, fever, and perspiration are present due to depression and stagnation of ministerial fire, symptoms such as bloody stool with pus, purulent abscess, sore throat, and inability to lie down due to agitation show, which signal negative prognosis. In bad cases of Reverting Yin Disease, there is continuous diarrhea and bloody stool with pus, which can be due to either Kidney Yang deficiency or depression and stagnation of ministerial fire. It could also be caused by excessive heat.

산불확산패턴 연구를 위한 시뮬레이션 모델 (A Simulation Model for the Study on the Forest Fire Pattern)

  • 송학수;전원주;이상희
    • 한국시뮬레이션학회논문지
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    • 제22권2호
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    • pp.101-107
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    • 2013
  • 최근 지구 온난화 현상으로 이상기후가 세계 곳곳 에서 발생하고 있으며, 이는 빈번한 산불 발생 및 산불의 대형화에 많은 기여를 하고 있다는 것이 보고되고 있다. 산불은 재산피해, 인명피해 뿐만 아니라 특히, 생태계 파괴를 촉진시키는 매우 심각한 요인 중의 하나이다. 산불로 인한 생태계 파괴 문제를 해결하기 위한 방안으로, 다양한 산불확산 및 패턴 수리모델이 개발되어져 왔다. 본 연구에서는, 바람 요인이 고려된 산불패턴을 시뮬레이션 할 수 있는 수리 모델을 제안하였다. 모델은 격자기반위에서 구성되었으며 셀룰라오토마타 방법을 사용하였다. 모델에서, 숲은 불이 쉽게 옮겨 붙는 나무와 그렇지 않은 나무 두 종류로 구성되었다. 산불이 확산되는 과정에서 연소된 나무의 개수가 전체 시뮬레이션 격자개수의 25% (= 10,000) 되는 시점(T)을 세 개의 독립변수인, 전체 나무밀도, 불 전이 확률이 큰 나무 밀도, 그리고 바람의 세기에 대해 어떤 영향을 받는지를 조사하였다. 나무 밀도가 커질수록, T의 값은 줄어들었고, 바람의 세기가 커질수록 T의 값이 줄어들었다. 나무밀도가 너무 크거나 작은 경우, 바람의 효과가 감소하였다. 본 연구에서, 제안한 산불확산모델은 실제 산불 문제에 적용되어 효과적 대응방안 마련에 많은 도움이 될 것으로 예상된다.

국내 방화규정에 따른 건축물 방화구획 성능 및 개선방안에 관한 연구 (A Study on the Performance and the Improving Methods of the Building Fire Compartment under the Domestic Fire Safety Regulations)

  • 천우영;이광원;이지희;김화중
    • 한국화재소방학회:학술대회논문집
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    • 한국화재소방학회 2008년도 춘계학술논문발표회 논문집
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    • pp.19-24
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    • 2008
  • Recently, the buildings have gradually become higher, more massive and more complex with high growth of economy and varieties of the patterns of people's living. Therefore we study a performance and Improving Methods of the fire compartment as a measure to minimize the damage of the people and property from the fire. Currently, under the economic crisis situation, we do not consider about prevention of disaster safety enough; safety investment evasion, safety carelessness, and management relaxation etc. Also in the aspect of regulation system, industrial technology and plan engineering, Korean techniques of preventing fire disasters are far behind of other advanced nations. At this point, we are in need of improving about it. When considering like this situation, we need more studies on the practical improvement in order to assure fire prevention for buildings. The fire compartment prevent from magnifying the fire to the wide area by compartment into specific area. From this, it is possible to minimize fire damage and property and secure emergency exit for life safety. This fire compartment has primary function to extinguish fire easily, and the openings and penetrations are important passage which makes the smoke and fire go away from the fire area to the contiguous space. This study suggests improving methods of domestic fire compartment efficiency standard through comparative analysis of overseas advanced provision and domestic provision about base element of the building fire prevention.

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장대 터널에서의 배연방식에 따른 기류 및 연기거동 연구 (Study on Flow and Smoke Behaviors on in Longitudinal Tunnel)

  • 김원태;최만용;빅정학;채경희
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2009년도 하계학술발표대회 논문집
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    • pp.1521-1527
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    • 2009
  • This study is aimed to analyze the floe patterns and thermal characteristics by computer simulation under the variations of fire strength for the logitudinal tunnel, from which flow and heat distributions are predicted in the longitudinal tunnel. Through the results of numerical computations, followings are found; one is that the volume flow rate is discontinuously increasing as closer to fire location, and the other is that a critical design to get the faster flow rate is required because of existence of backlayer flow for the high fire strength in view of safety for the people in fire of the tunnel.

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종류식 터널내 소요 환기량에 의한 터널환기 및 화재 시뮬레이션 연구 ( 임고 4 터널 ) (Fire Simulation Study and Tunnel Ventilation of Requirement in the Longitudinal Tunnel. (In Yimgo-4th Tunnel))

  • 채경희
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2008년도 하계학술발표대회 논문집
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    • pp.1378-1385
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    • 2008
  • This study is aimed to analyze the flow patterns and thermal characteristics by computer simulation under the variations of fire strength for Daegu-Pahang Yimgo-4th tunnel, from which flow and heat distributions are predicted in the longitudinal tunnel. Though the results of numerical computations, followings are found; one is that the volume flow rate is discontinuously increasing as closer to fire location, and the other is that a critical design to get faster flow rate is required because of existence of backlayer flow for the high fire strength in view of safety for the people in fire of the tunnel.

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사암침법(舍岩鍼法) 화열문(火熱門)의 군화방(君火方)과 상화방(相火方)에 대한 연구 (A Study on the Principles of Prescriptions of the King Fire and the Premier Fire of Saam Acupuncture)

  • 사공희찬;임낙철;강정수
    • 혜화의학회지
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    • 제13권1호
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    • pp.27-38
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    • 2004
  • Saam acupuncture has an evident principles of prescription based on acupuncture tonification and purgation of Nan-gyeong but many prescriptions of Saam acupuncture are not typical patterns. Therefore it is difficult to understand principles of those prescriptions. Understanding the principles of any prescription means understanding the physiology and pathology of that prescription and it have an important role in selecting the best prescription and taking the most effective treatment. This paper studies principles of prescriptions of the king fire and the premier fire. The theoretical authorities of analysis are Nan-gyeong, works of Joo dan-gye and Li dong-won and Uihakimmun. The damage of fire to mentality is very intensive and severe. The prescriptions of the king fire and premier fire have a good effect on diseases by fire. The fire of human body are two types, the king fire and the premier fire but the water of human body is only one and then inferior to fire. The fire superior to the water is unstable and the fire influences rapidly and intensively on four elements, wood, earth, metal, water. So the control of the water is the key to treat the disease by fire. Considering the attack and the treatment of disease, heart and liver are attacked with a disease by fire in its early stage and kidney and lung are the key to treatment. Consequently the pathology of the disease by fire is corresponding to the theory- Yang Sufficient, Yin Deficient- of Joo dan-gye. It seems that the theory of Joo dan-gye influenced on the medical theory of Saam Acupuncture. On that account I believe that the study of medical theories of the Geum and Won Dynasty that various medical theories appeared is very available.

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Post-fire Repair of Concrete Structural Members: A Review on Fire Conditions and Recovered Performance

  • Qiu, Jin;Jiang, Liming;Usmani, Asif
    • 국제초고층학회논문집
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    • 제10권4호
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    • pp.323-334
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    • 2021
  • Concrete structures may rarely collapse in fire incidents but fire induced damage to structural members is inevitable as a result of material degradation and thermal expansion. This requires certain repairing measures to be applied to restore the performance of post-fire members. A brief review on investigation of post-fire damage of concrete material and concrete structural members is presented in this paper, followed by a review of post-fire repair research regarding various types of repairing techniques (FRP, steel plate, and concrete section enlargement) and different type of structural members including columns, beams, and slabs. Particularly, the fire scenarios adopted in these studies leading to damage are categorized as three levels according to the duration of gas-phase temperature above 600℃ (t600). The repair effectiveness in terms of recovered performance of concrete structural members compared to the initial undamaged performance has been summarized and compared regarding the repairing techniques and fire intensity levels. The complied results have shown that recovering the ultimate strength is achievable but the stiffness recovery is difficult. Moreover, the current fire loading scenarios adopted in the post-fire repair research are mostly idealized as constant heating rates or standard fire curves, which may have produced unrealistic fire damage patterns and the associated repairing techniques may be not practical. For future studies, the realistic fire impact and the system-level structural damage investigation are necessary.

폼 분무 노즐 방사 분포 및 폼의 열적 특성 연구 (Thermal Characteristics of Foams and Discharge of Fire-Protection Foam Spray Nozzle)

  • 김홍식;김윤제
    • 대한기계학회논문집B
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    • 제29권1호
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    • pp.151-158
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    • 2005
  • A characteristic of discharge for a foam spray nozzle with various parameters was investigated. The discharge patterns from a fire foam spray nozzle are important to evenly spray over a maximum possible floor area. Two parameters of a foam spray nozzle were chosen, and compared with those from the standard one. Also, in order to evaluate the performance of discharged foam agents used to protect structures from heat and fire damages, the thermal characteristics of fire-protection foams were experimentally investigated. A simple repeatable test for fire-protection foams subjected to fire radiation was developed. This test involves foam generation equipment, a fire source for heat generation, and data acquisition techniques. Results show that the bubble size of foam is increased by large inside diameter of orifice or closed air hole, but phenomenon of discharge angle and expansion ratio is opposite. For the case of the open air hole, liquid film of a circular cone discharges with formation, growth, split and fine grain. In case of the closed air hole, a pillar of foam solution discharges with that. Though the temperature gradient in the foam increases with increased foam expansion ratio. it is not change with increased intensity of heat flux.