• Title/Summary/Keyword: fire point

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Evaluation on Spalling Properties of Ultra High Strength Concrete with Melting and Vaporization of Fiber (유기섬유의 용융 및 기화에 따른 초고강도 콘크리트의 폭렬 특성 평가)

  • Kim, Gyu-Yong;Choe, Gyeong-Cheol;Lee, Joo-Ha;Lee, Seung-Hoon;Lee, Tae-Gyu
    • Journal of the Korea Concrete Institute
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    • v.24 no.2
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    • pp.173-183
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    • 2012
  • Recently, experimental studies to prevent explosive spalling based on spalling mechanism and addition of Polypropylene fiber in high strength concrete (HSC) are performed actively. However, with respect to ultra high strength concrete (UHSC), its compact internal structure is more difficult release vapor pressure at rapid rising temperature compared to HSC. Therefore, in this study, an experiment was conducted to evaluate spalling properties of UHSC using ${\Box}$ $100mm{\times}100{\times}H200mm$ rectangular specimen according to ISO-834 standard fire curve. With respect melting point of fiber, three fiber types of Polyethylene, Polypropylene, and Nylon fibers with melting temperature of $110^{\circ}C$, $165^{\circ}C$, and $225^{\circ}C$, respectively, were considered. Mixed fiber of 0.15% and 0.25% of concrete volume was used to consider spalling properties based on water vapor pressure release. Then, TGDTA test on fiber and FEM analysis were performed. The results showed that it is difficult to prevent initial spalling without loss of fiber mass even if fiber melting temperature is low. Also, in preventing thermal spalling, fiber that melts to rapidly create porosity within 10 minutes of fire is more effective than that of low melting temperature property of fiber.

Regional Analysis of Forest Eire Occurrence Factors in Kangwon Province (강원도 지역 산불발생인자의 지역별 유형화)

  • 이시영;한상열;안상현;오정수;조명희;김명수
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.3 no.3
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    • pp.135-142
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    • 2001
  • This study attempts to categorizes the factors of forest fire occurrences based on regional meteorologic data and general forest no characteristics of 18 cities and guns in Kangwon province. lo accomplish this goal, some statistical analyses such as analysis of variance, correspondence analysis and multidimensional scaling were adopted. To reveal the forest fires pattern of study region, a categorization process was conducted by employing the quantification approach which modified and quantified the metric-data of fire occurrence dates. Also, The fire occurrence similarity was compared by using multidimensional scaling for each study region. The major results are summarized as follows: It was found that the meteorological factors emerged as different to each region are average and maximum temperature, minimum dew point temperature and average and maximum wind speed. In the result of correspondence analysis representing relationships between fire causes and study regions, Kangrung is caused by arsonist, Chulwon, Hwachen and Yanggu caused by military factor, Sokcho and Chunchen caused by the debris burning, and Samchuk caused by general man-caused fires, respectively. Finally, the forest fire occurrence pattern of this study regions were divided into five areas such as, group I including Samchuk, Kangryung, Chunchen, Wonju, Hongchen and Hhoingsung, group II including Donghae, Taebaek, Yangyang and Pyongchang, group III including Jungsun, Chulwon and Whachen, group Ⅵ including Gosung, Injae and Yanggu, and group V including Shokcho and Youngwol.

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Developing Mobile GIS Spatial Data Compression Method for Forest Fire Extinguishment Information Management (산불진화정보 관리를 위한 Mobile GIS 공간 데이터 압축기법 개발)

  • Jo, Myung-Hee;Lee, Myung-Bo;Lee, Si-Young;Kim, Joon-Bum;Kwon, Bong-Kyum;Heo, Young-Jin
    • Journal of the Korean Association of Geographic Information Studies
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    • v.7 no.2
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    • pp.78-86
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    • 2004
  • Recently GPS and mobile GIS technologies based on LBS(location based service) have played an important role as DSS(decision supporting system) for domestic forest fire extinguishment policies. In this study forest fire extinguishments information management system based on mobile GIS technique was designed to seize the exact location on wireless network so that it helps to guide the safe and efficient extinguishments affairs and provide the extinguishments environment toward ground fighting teams and the central forest government in real time. Moreover, possibly to operate this system, the foundation technologies by the name of '.gci' such as the spatial data compression method, the spatial data transmission method over wireless network and the spatial analysis interface on PDA should be mainly considered. Especially, in this study the spatial data compression method having high compression rate from 51% to 62% for each polygon, line, and point data, without the loss of data was developed.

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Cognitive behavior intervention for critical incident stress management in fire fighters in Korea (소방공무원의 위기상황 스트레스 관리를 위한 인지행동 개입과 대책)

  • Lee, Eun-Jung;Kim, Jee-Hee
    • Journal of the Korea Convergence Society
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    • v.6 no.2
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    • pp.13-18
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    • 2015
  • The purpose of the study is to investigate the predisposing factors of posttraumatic stress disorder (PTSD) in fire fighters in Korea and to suggest the program development and solution to the critical incident stress management (CISM) in the future. PTSD is characterized by invasion, withdrawal, negative change of cognition and mood, and hypersensitivity. Trauma memory includes explicit memory and implicit memory. The explicit memory is conscious, cognitive, and descriptive and is controlled by hippocampus. The data of explicit memory have inhibitive and narrative language structure. The implicit memory is inconscious, emotional, and remembered by the body. The implicit memory is controlled by amygdala and has inexpressive language structure. The deletion of implicit memory is the key point to trauma treatment. Critical incident stress management (CISM) is the approach for the solution of PTSD. In conclusion, the essential goal of CISM is the psychological cessation of PTSD. This study tried to suggest the education program development of PTSD.

Ecological Green Roofs in Germany

  • Kohler, Manfred
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.7 no.4
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    • pp.8-16
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    • 2004
  • The industrialization of central Europe more than 100 ago marked the beginning of densely concentrated buildings in quickly growing cities. A cheap type of roofing material of that time was tar. But it was dangerous because it was high inflammable. Then some roofer had a splendid idea. They used sandy material as a final layer atop the impermeable tar layer. These roofs were much more fire resistant than the typical roofs. In this sandy layer some plant species began to grow spontaneously. This was the beginning of the green roof history of modern Europe. A number of these green roofs survived both world wars. In the early 80's in Berlin alone, 50 such buildings existed and they continued to be waterproof until the present day. Since the 1992 Earth Summit of 1992 in Rio de Janeiro(http://www.johannesburgsummit.org/html/basic_info/unced.html) the term "sustainable development" became of central interest of urban designers. In city regions green roofs had become synonymous with this term. With a small investment, long-lasting roofs can be created. Further back in history, more exciting examples of green roofs can be found. The hanging gardens of antiquity are well-known. There are also green roofs built as insulation against cold and heat all over the world. For over 20 years, roof greening in central Europe has been closely examined for various reasons. Roof greening touches several different disciplines. Of primary interest is the durability of the roofs. But ecologists are also interested in green roofs, for instance in biodiversity research. The beneficial effect of greening on water proofing was also proven. For some time, the issue of fire protection was investigated. According to tests, green roofs received a harsh careful rating. Their fire protective property is considered similar to that of tile roofs. Another recent impulse for the green roof movement in Germany has come from the evident improvement of storm water retention and the reduced burden on the sewer system. The question of whether and how much energy green roofs can save has become an urgent question. The state of the research and also various open questions from a central European point of view will be discussed in the context of international collaboration. Apart from academic considerations, those who involve themselves in this issue take a predominantly positive view of the numerous existing green roofs in Germany. In some cities, green roofs are the typical construction technique for new buildings. A few outstanding examples will conclude this review. In Germany, about 20 companies, some of which operate internationally, specialize in green roof consulting. Learning from each other in an open-ended way with respect to different construction techniques and applications in various climatic regions can only be accomplished through such international collaboration as is taking place here.

Risk Assessment of Semiconductor PR Process based on Frequency Analysis of Flammable Material Leakage (반도체 PR 공정의 인화성 물질 누출 빈도분석을 통한 위험성 평가)

  • Park, Myeongnam;Chun, Kwang-Su;Yi, Jinseok;Shin, Dongil
    • Journal of the Korean Institute of Gas
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    • v.25 no.5
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    • pp.1-10
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    • 2021
  • Semiconductor Photo Resist (PR) automation equipment uses a mixture of several flammable substances, and when it leaks during the process, it can lead to various accidents, therefore, risk assessment is necessary. This study analyzed the frequency of leakage of Acetone and PGMEA used in PR automation equipment and the frequency at which such leakage could lead to a fire accident through the frequency analysis method, and evaluated the need for additional risk reduction measures in the current facility. Based on the process leak data and ignition probability data of IOGP, leak frequency analysis and ignition probability were derived, and the frequency of actual fire accidents was analyzed by combining them. The frequency of material leakage in semiconductor PR process is 7.30E-03/year, and fire accidents can occur by acetone that exists above the flash point when the material is leaked, the frequency was calculated at the level of 1.24E-05/year. According to the UK HSE, for a major accident occurring with a frequency of 1.24E-05/year, it is defined as "Broadly Acceptable", a level that does not require additional measures for risk reduction when it causes 7 or less deaths, and due to the process operated by two people, no additional risk reduction are required.

Safety Evaluation of Evacuation in a Dormitory Girls' High School based on PAPS (PAPS에 기반한 여자고등학교 기숙사생의 피난 안전성 평가)

  • Jeon, Seung-duk;Kong, Ha-sung
    • The Journal of the Convergence on Culture Technology
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    • v.8 no.1
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    • pp.469-481
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    • 2022
  • This study is for increasing evacuation safety by analyzing RSET(the required safe escape time) through the arrangement of personnel by floor and by room while evacuating in a Girls' High School Dormitory. For this study, PAPS(Physical Activity Promotion System) results that have not been studied so far were analyzed and reflected in evacuation simulations on the premise that individual student's physical strength can affect evacuation. Based on the PAPS results, four scenarios were applied. In addition, evacuation simulation using the pathfinder program was conducted in two situations: the evacuation route was assigned or not. Scenario 4 was the fastest at 168.5 seconds of RSET in assigning evacuation routes among scenarios. As a result of this study, the arrangement of students focusing on improving their academic ability and student life guidance excluding student physical strength has problem. In order to solve this problem, it is effective to place C group students(low grade on PAPS) on low floors and A group students(high grade on PAPS) on high floors and to assign evacuation routes in each room. In the future, the following ways need to be more studied. A study on how to increase evacuation safety through practical evacuation training, the way of assessing evacuation safety reflecting the lifestyle and physical strength of girls, the evacuation route assignment according to the fire occurrence point, and the method to secure evacuation routes in the event of a fire near stairs or entrances should be conducted.

Comparison of Partial Least Squares and Support Vector Machine for the Flash Point Prediction of Organic Compounds (유기물의 인화점 예측을 위한 부분최소자승법과 SVM의 비교)

  • Lee, Chang Jun;Ko, Jae Wook;Lee, Gibaek
    • Korean Chemical Engineering Research
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    • v.48 no.6
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    • pp.717-724
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    • 2010
  • The flash point is one of the most important physical properties used to determine the potential for fire and explosion hazards of flammable liquids. Despite the needs of the experimental flash point data for the design and construction of chemical plants, there is often a significant gap between the demands for the data and their availability. This study have built and compared two models of partial least squares(PLS) and support vector machine(SVM) to predict the experimental flash points of 893 organic compounds out of DIPPR 801. As the independent variables of the models, 65 functional groups were chosen based on the group contribution method that was oriented from the assumption that each fragment of a molecule contributes a certain amount to the value of its physical property, and the logarithm of molecular weight was added. The prediction errors calculated from cross-validation were employed to determine the optimal parameters of two models. And, an optimization technique should be used to get three parameters of SVM model. This work adopted particle swarm optimization that is one of heuristic optimization methods. As the selection of training data can affect the prediction performance, 100 data sets of randomly selected data were generated and tested. The PLS and SVM results of the average absolute errors for the whole data range from 13.86 K to 14.55 K and 7.44 K to 10.26 K, respectively, indicating that the predictive ability of the SVM is much superior than PLS.

The Literature Study on Classification of Cause and the Effect of Acupuncture and Moxibustion Treatment for Dentalgia (치통(齒痛)의 병인병기(病因病機) 및 침구치료(鍼灸治療)에 대(對)한 문헌적(文獻的) 고찰(考察))

  • Lee, Seong-no;Lee, Hyun;Lee, Byung-ryul
    • Journal of Haehwa Medicine
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    • v.10 no.1
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    • pp.269-286
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    • 2001
  • Objectives : This Investigation was aimed to find out the Classification of Cause and the Effect of Acupuncture and Moxibustion Treatment for Dentalgia Methods : We surveyed the oriental medical books from $\ll$HungTiNeiChing$\gg$ to recent published books concerning the Acupuncture therapy for Dentalgia Results : 1. Since the time of $\ll$HungTiNeiChing$\gg$ there was called "yateng", "yatong", "chiyaqutong", "kouchitong", "nichi", "chichong", "fengchi", "chongshitong", "chongshiyachi", "chifengzhongtong", "chiyinzhong", "yachuangzhongtong" 2. The Oriental Medical cause of Dentalgia are fire, wind, cold, blood stasis, stomach-heat, phlegm, difficiency of kidney, late snack, insect and wound, and then the Western Medical cause are cacodontia, periodontal disease, trigeminal nerve pain, stress 3. The meridians used for the treatment are large intestine, stomach, triple warmer, gallbladder and small intestine 4. The most frequently used acupuncture point for the treatment are Hapkok(LI3), Naejong(S44), Hyopko(S6), Igan(LI2), Sohae(H3), Yanggok(SI5), Hagan(S7), Taeyong(S5), Samgan(LI3), Kokehi(LI11) 5. The most frequently used moxibustion for the treatment are Sungjang(CV24), Yolgyol(L7), Kyonu(LI15), Taeyon(L9), Hapkok(LI3) 6. In the superior dental pain there commonly used the acupuncture point of stomach meridian, triple warmer meridian, gallbladder meridian in the inferior dental pain there commonly used the acupuncture point of large intestine meridian. 7. The most frequently used acupuncture point for the superior dental pain are Naejong(ST44), Yanggok(SI5), Chongnyong(G17), Kakson(TE20), In the inferior detal pain there are Taeyong(S5), Hapkok(LI3), Igan(LI2), Sangyang(LI1), Samgan(LI3) 8. In the treatment of dental pain The Acupuncture therapy utilized the division of region are the Erzhen therapy(耳針療法), the Touzhen therapy(頭鍼療法), the Shouzhen therapy(手鍼療法), the Zuzhen therapy(足鍼療法), the Bizhen therapy(鼻針療法), the Wanhuaizhen therapy 9. In dental pain the other therapy are the Taozhen therapy(陶鍼療法), the Pifuzhen therapy(皮膚針療法), the Dianzhen therapy(電鍼療法), the Yaozhen therapy(藥針療法).

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A Study on 3D Model Building of Drones-Based Urban Digital Twin (드론기반 도심지 디지털트윈 3차원 모형 구축에 관한 연구)

  • Lim, Seong-Ha;Choi, Kyu-Myeong;Cho, Gi-Sung
    • Journal of Cadastre & Land InformatiX
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    • v.50 no.1
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    • pp.163-180
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    • 2020
  • In this study, to build a spatial information infrastructure, which is a component of a smart city, a 3D digital twin model in the downtown area was built based on the latest spatial information acquisition technology, the drone. Several analysis models were implemented by utilizing. While the data processing time and quality of the three types of drone photogrammetry software are different, the accuracy of the construction model is ± 0.04 in the N direction and ± 0.03m in the E direction. In the m and Z directions, ± 0.02m was found to be less than 0.1m, which is defined as the allowable range of surveying performance and inspection performance for the boundary point in the area where the registration of the boundary point registration is executed. 1: 500 to 1 of the aerial survey work regulation: The standard deviation, which is the error limit of the photographic reference point of the 600 scale, appeared within 0.14 cm, and it was found that the error limit of the large scale specified in the cadastral and aerial survey was satisfied. In addition, in order to increase the usability of smart city realization using a drone-based 3D urban digital twin model, the model built in this study was used to implement Prospect right analysis, landscape analysis, Right of light analysis, patrol route analysis, and fire suppression simulation training. Compared to the existing aerial photographic survey method, it was judged that the accuracy of the naked eye reading point is more accurate (about 10cm) than the existing aerial photographic survey, and it is possible to reduce the construction cost compared to the existing aerial photographic survey at a construction area of about 30㎢ or less.