• Title/Summary/Keyword: Fire occurrence

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Prediction of Poor Contact by Analysis of Electrical Signal and Thermal Characteristics (전기적 신호와 열적특성 분석에 의한 접촉불량 예측)

  • Lee, Heung-Su;Kim, Doo-Hyun;Kim, Sung-Chul;Kim, Yoon-Bok
    • Journal of the Korean Society of Safety
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    • v.27 no.3
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    • pp.36-41
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    • 2012
  • Electrical Connections often cause fires due to poor contact. Occurrence rate of these fires tends to increase annually. The reason why poor contacts occur is often because it is the low mechanical pressure at the contact points. A typical connection method using mechanical pressure is a screw terminal type. This study reviewed these poor contact cases in the screw terminals. In order to get reproduction of such cases, two types of experiments were conducted. the first one was conducted under the normal contact condition, and the other one was conducted under the poor contact condition that screw terminal of breaker was loosen and did not meet the requirements of toque value. In both types of experiments, compulsory vibration was adopted as a variable to aggravate poor contacts. Each of various current values(4.5A, 9.0A, 13.5A) is input. In these experiments, relationships of a contact, electrical signal such as current and electric pulse by ZCT and thermal characteristics according to vibration effect are analyzed. The suggested data and results in this study provide the useful resources helping to investigate fires due to poor contact, and they develop the detector for poor contact and finally reduce the electrical fire occurrence rate.

Prediction of Forest Fire Hazardous Area Using Predictive Spatial Data Mining (예측적 공간 데이터 마이닝을 이용한 산불위험지역 예측)

  • Han, Jong-Gyu;Yeon, Yeon-Kwang;Chi, Kwang-Hoon;Ryu, Keun-Ho
    • The KIPS Transactions:PartD
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    • v.9D no.6
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    • pp.1119-1126
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    • 2002
  • In this paper, we propose two predictive spatial data mining based on spatial statistics and apply for predicting the forest fire hazardous area. These are conditional probability and likelihood ratio methods. In these approaches, the prediction models and estimation procedures are depending un the basic quantitative relationships of spatial data sets relevant forest fire with respect to selected the past forest fire ignition areas. To make forest fire hazardous area prediction map using the two proposed methods and evaluate the performance of prediction power, we applied a FHR (Forest Fire Hazard Rate) and a PRC (Prediction Rate Curve) respectively. In comparison of the prediction power of the two proposed prediction model, the likelihood ratio method is mort powerful than conditional probability method. The proposed model for prediction of forest fire hazardous area would be helpful to increase the efficiency of forest fire management such as prevention of forest fire occurrence and effective placement of forest fire monitoring equipment and manpower.

Deregulation of the Fire Prevention Legislation; and Its Impact on Fire Occurrence - Case of the United Kingdom - (′화재예방법규′의 규제완화가 화재발생에 미치는 영향 -영국 사례분석 -)

  • 이재열
    • Fire Science and Engineering
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    • v.15 no.2
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    • pp.13-19
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    • 2001
  • The OECD defines regulatory reform as both better regulation and deregulation, and emphasizes that governments must continue to regulate in areas such as environmental quality and safety. In contrast, Korean regulatory reform in fire services in the 1990s shows quite a strange trend, having been carried out only to the direction of softening and abolishing regulations. In the UK, fire prevention legislation has been strengthened since the enactment of the Fire Precautions Act 1971, and the Building Regulations 1991, which apply to all new buildings including a private house, require that there should be at least one smoke alarm on each floor. This research shows that the tightening of fire prevention legislation in the UK has promoted fire safety, which is very instructive for Korean fire services. In order for Korean fire services to protect citizens'lives and property from fires, one of basic directions of regulatory reform, to improve the quality of regulations relating to safety, health and the environment, should be observed strictly. Moreover, the flexibility of the basic direction of regulatory reform should be ensured so that the regulations concerning safety could be even increased under the overall reform strategy of reducing all regulations.

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An Experimental Study on Thermal Damage and Spalling of Concrete Lining in Tunnel Fire (터널화재시 콘크리트 라이닝의 폭렬 및 화재손상에 관한 실험적 연구)

  • Kim, Heung-Youl;Kim, Hyung-Jun;Cho, Kyung-Suk;Lee, Jae-Sung;Kwan, Ki-Hyuk
    • Fire Science and Engineering
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    • v.23 no.3
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    • pp.110-120
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    • 2009
  • In tunnel, though the frequency of fire occurrence is relatively lower than other structures, the characteristics of sealed space tends to cause the temperature to rapidly rise to more than $1000^{\circ}C$ within 5minutes after fire, which might eventually lead to a large fire that usually results in a loss of lives and the damage to the properties, not to mention a huge cost necessary for repair and maintenance after fire. We have developed various conditions of the heating furnace and the method to install a thermo couple within the furnace based on EFNARC and KS F 2257-1. Referring to tunnel fire scenarios, it clarified the heat transfer characteristics of concrete PC panel lining depending on fire intensity (ISO, $1^{\circ}C$/SEC, MHC, RWS), and to identify the range of thermal damage, the evaluation was carried out using ITA standard. As a result, 30mm under ISO fire condition, 20mm under $1^{\circ}C$/SEC, 100mm under MHC and 50mm under RWS were measured. And when it comes to spalling, 30mm was measured under RWS and MHC.

Non-Fire Alarm Management and Customized Automatic Guidance System (비화재보 관리 및 맞춤형 자동안내 시스템)

  • Hyo-Seung Lee;Ju-Sang Lee;Woo-Jun Choi
    • The Journal of the Korea institute of electronic communication sciences
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    • v.18 no.2
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    • pp.355-360
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    • 2023
  • Fire is a disaster that causes irreversible damage to many people due to personal injury and property damage. Various fire detection equipments are installed around us to detect and cope with it quickly. However, due to various problems such as artificial, environmental, and aging, fire detection equipment is activated even though it is not a actual fire, and there are many problems such as delaying the support to the necessary fire scene. In this paper, we analyze the non-fire alarm of the fire detection equipment and propose a system that enables the field staff to check the scene situation through the video as a way to prevent the mobilization due to the misinformation by checking the fire. The purpose of the present invention is to stably cope with a disaster by suggesting a customized automatic guidance system which induces a rapid evacuation by sending an evacuation guidance notification to a range of a fire occurrence neighboring area, and supports a rapid and accurate processing by a rapid dispatch of a firefighter, rather than a wide range of guidance such as an existing emergency disaster guidance letter when it is determined to be an actual fire through the confirmation procedure.

Developing Fire-Danger Rating Model (산림화재예측(山林火災豫測) Model의 개발(開發)을 위(爲)한 연구(硏究))

  • Han, Sang Yeol;Choi, Kwan
    • Journal of Korean Society of Forest Science
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    • v.80 no.3
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    • pp.257-264
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    • 1991
  • Korea has accomplished the afforestation of its forest land in the early 1980's. To meet the increasing demand for forest products and forest recreation, a development of scientific forest management system is needed as a whole. For this purpose the development of efficient forestfire management system is essential. In this context, the purpose of this study is to develop a theoretical foundation of forestfire danger rating system. In this study, it is hypothesized that the degree of forestfire risk is affected by Weather Factor and Man-Caused Risk Factor. (1) To accommodate the Weather Factor, a statistical model was estimated in which weather variables such as humidity, temperature, precipitation, wind velocity, duration of sunshine were included as independent variables and the probability of forestfire occurrence as dependent variable. (2) To account man-caused risk, historical data of forestfire occurrence was investigated. The contribution of man's activities make to risk was evaluated from three inputs. The first, potential risk class is a semipermanent number which ranks the man-caused fire potential of the individual protection unit relative to that of the other protection units. The second, the risk sources ratio, is that portion of the potential man-caused fire problem which can be charged to a specific cause. The third, daily activity level is that the fire control officer's estimate of how active each of these sources is, For each risk sources, evaluate its daily activity level ; the resulting number is the partial risk factor. Sum up the partial risk factors, one for each source, to get the unnormalized Man-Caused Risk. To make up the Man-Caused Risk, the partial risk factor and the unit's potential risk class were considered together. (3) At last, Fire occurrence index was formed fire danger rating estimation by the Weather Factors and the Man-Caused Risk Index were integrated to form the final Fire Occurrence Index.

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Development of Fire Detection Algorithm using Intelligent context-aware sensor (상황인지 센서를 활용한 지능형 화재감지 알고리즘 설계 및 구현)

  • Kim, Hyeng-jun;Shin, Gyu-young;Oh, Young-jun;Lee, Kang-whan
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2015.05a
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    • pp.93-96
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    • 2015
  • In this paper, we introduce a fire detection system using context-aware sensor. In existing weather and based on vision sensor of fire detection system case, acquired image through sensor of camera is extracting features about fire range as processing to convert HSI(Hue, Saturation, Intensity) model HSI which is color space can have durability in illumination changes. However, in this case, until a fire occurs wide range of sensing a fire in a single camera sensor, it is difficult to detect the occurrence of a fire. Additionally, the fire detection in complex situations as well as difficult to separate continuous boundary is set for the required area is difficult. In this paper, we propose an algorithm for real-time by using a temperature sensor, humidity, Co2, the flame presence information acquired and comparing the data based on multiple conditions, analyze and determine the weighting according to fire it. In addition, it is possible to differential management to intensive fire detection is required zone dividing the state of fire.

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Fire Resistance of Repaired High Strength Concrete Column Damaged by Fire (화재 피해를 입은 고강도 콘크리트 기둥의 보수공법 변화에 따른 내화특성)

  • Park, Chun-Jin;Back, Dae-Hyun;In, Gi-Ho;Yeo, In-Hwan;Min, Byung-Yeol;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2009.11a
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    • pp.113-116
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    • 2009
  • This study analyzed fire-resistant characteristics according to changes in repair methods of PFH mixed high-strength concrete roof structures having undergone fire damage. The results of the study are as follows. First, as a repulsive characteristics of structures, the remaining repulsion was shown to increase following fire-resistance tests according to increases in depth of coverings. The results of the relationship between depth of coverings and remaining repulsion rates following fire-proofing tests showed a high correlation. At a covering depth of 67.3mm, remaining repulsion rate was estimated to be 100%. For fire-resistant characteristics following repairs of structure, as for spalling, severe separation was shown in the case of general plaster while general plaster + Metal Lath showed overall superior spalling prevention. For internal structure temperatures, general plaster showed max temperatures of 705℃, average temperatures of 636℃ while general plaster + metal lath showed max temperature of 660℃ and average temperature of 520℃, demonstrating lower temperature distributions than use of only general plaster. In conclusion, after removing the covering of structures damaged due to high temperatures of fires within high-strength concrete installations, the use of fire-resistant mortars and applying metal laths on surfaces of general plaster will provide superior fire-resistance performance in the occurrence of a 2nd fire.

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Recognition of Fire Levels based on Fuzzy Inference System using by FCM (Fuzzy Clustering 기반의 화재 상황 인식 모델)

  • Song, Jae-Won;An, Tae-Ki;Kim, Moon-Hyun;Hong, You-Sik
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.11 no.1
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    • pp.125-132
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    • 2011
  • Fire monitoring system detects a fire based on the values of various sensors, such as smoke, CO, temperature, or change of temperature. It detects a fire by comparing sensed values with predefined threshold values for each sensor. However, to prevent a fire it is required to predict a situation which has a possibility of fire occurrence. In this work, we propose a fire recognition system using a fuzzy inference method. The rule base is constructed as a combination of fuzzy variables derived from various sensed values. In addition, in order to solve generalization and formalization problems of rule base construction from expert knowledge, we analyze features of fire patterns. The constructed rule base results in an improvement of the recognition accuracy. A fire possibility is predicted as one of 3 levels(normal, caution, danger). The training data of each level is converted to fuzzy rules by FCM(fuzzy C-means clustering) and those rules are used in the inference engine. The performance of the proposed approach is evaluated by using forest fire data from the UCI repository.

A study of the HRR and fire propagation phenomena for the fire safety design of deep road tunnel (대심도터널 화재 안전 설계를 위한 승용차의 열방출률 및 화재전파 특성에 관한 연구)

  • Yoo, Yong-Ho;Kweon, Oh-Sang
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.12 no.4
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    • pp.321-328
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    • 2010
  • The study performed an actual fire experiment in order to propose the heat release rate of automobile that is the most basic architectural element for the fire safety design in a tunnel, whose importance has been recognized as the underground traffic tunnels are planned in Korean metropolitan cities. The heat release rate of a van is measured by the large scale calorimeter, in which the law of oxygen consumption is applied, and the fire expansion characteristics in a tunnel by placing two passenger cars nearby one another in the tunnel. As the results, the heat release rate of the van was revealed to be 5.9 MW, and carbon monoxide was emitted 482 ppm at a maximum. In case of two passenger car experiment for the fire expansion characteristics, the adjacent car was ignited about 3 minutes 30 seconds after the fire occurrence, and the complete fire was developed after 15 minutes. The maximum heat release was 9 MW. The results from the actual fire experiment can be an important input data for future quantitative analysis as well as an element applicable to a tunnel disaster preventive equipment design.