• Title/Summary/Keyword: 화재 특성

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Method to Derive the Optimal Vent Position when Flammable Liquid Leaks Based on CFD (CFD 기반 인화성 액체 누출 시 최적의 환기구 배치 도출 방안)

  • Eun-Hee Kim;Seung-Hyo An;Jun-Seo Lee;Byung-Chol Ma
    • Journal of the Korean Institute of Gas
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    • v.28 no.1
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    • pp.11-18
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    • 2024
  • If flammable liquid leaks, vapor evaporated from the pool can cause poisoning or suffocation to workers, leading to secondary accidents such as fires and explosions. To prevent such damage, ventilation facilities shall be installed when designing indoor workplaces. At this time, the behavior varies depending on the characteristics of the leaked chemical, so it is necessary to select a suitable vent location according to the material. Therefore, 3D CFD simulations were introduced to derive optimal vent position and ventilation efficiency was quantitatively evaluated by vent position. At this time, assuming a situation in which flammable liquids leak at indoor workplaces to form pools, the concentration of vapor evaporated from pools was compared to derive the optimal vent position. As a result of research on toluene with high vapor density, ventilation efficiency was confirmed to be the highest at the upper supply-lower exhaust, and it is judged that introducing it can achieve about 3.7 times ventilation effect at the same maintenance cost. Through this study, it is expected that the workplace will be able to secure workers' safety by applying simulation results and installing ventilation ports.

Combustion Characteristics of Useful Imported Woods (국내 유용 해외 목재 수종의 연소특성 평가)

  • Seo, Hyun Jeong;Kang, Mee Ran;Park, Jung-Eun;Son, Dong Won
    • Journal of the Korean Wood Science and Technology
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    • v.44 no.1
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    • pp.19-29
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    • 2016
  • The purpose of this study is to analyze the combustion and thermal properties in order to establish baseline data for the fire safety evaluation of imported wood. The combustion properties such as heat release rate, total heat release, gas yield, and mass loss were analyzed by the method of cone calorimeter test according to KS F ISO 5660-1 and thermogravimetric analysis (TGA). Analyzed species are five kinds of species as Merbau, Mempening, Garo Garo, Malas, and Dillenia. The heat released rate values showed the highest value of Malas as $375.52kW/m^2$, and Dillenia showed the lowest value as $133.30kW/m^2$. The data values were confirmed in the following order: Malas > Mempening > Garo Garo > Merbau > Dillenia. In case of the total heat release, it was measured in the following order: Mempening > Malas > Garo Garo > Merbau > Dillenia. The gas analysis results were that Dillenia showed the highest value of 0.034. Also, Mempening and Malas showed the lowest at 0.020 in the $CO/CO_2$. Min of mass reduction was shown as 74.79% Sargent cherry, on the other hand, Malas had a 83.52%. It showed a correlation between and of the CO and $CO_2$ generation and combustion characteristics of wood. The thermal decomposition temperature of the wood in the TGA were as follow that Merbau $348.07^{\circ}C$, Mempening $367.57^{\circ}C$, Garo Garo $350.59^{\circ}C$, Malas $352.41^{\circ}C$, Dillenia $364.33^{\circ}C$. The aim of this study is to determine the combustion properties of imported wood according to ISO 5660-1. And, based on the results of this study, we would proceed with further research for improving the fire safety of wood for construction.

Growth and Yield Characteristics of Foxtail Millet, Proso Millet and Sorghum According to Sowing Date in Middle Area in Korea (중부지방에서 파종기에 따른 조, 기장, 수수의 생육 및 수량 특성)

  • Yoon, Seong-Tak;Jae, Eun-Kyeong;Kim, Young-Jung;Jeong, In-Ho;Han, Tae-Kyu;Kim, Tae-Yun;Cho, Young-Son;Kang, Hang-Won
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.60 no.2
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    • pp.197-211
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    • 2015
  • In order to investigate optimum and marginal sowing date of foxtail millet, proso millet and sorghum in middle area (Anseong, Gyeonggi province) of korea, four levels of sowing date [(May 15(1st), June 6(2th), June 26(3th), July 13(4th)] with mulching and non-mulching were treated in this experiment. We used three crops of foxtail millet, proso millet and sorghum with four varieties of Samdachal, Samdamae, Kyeongkwan1, Hwanggeumjo in foxtail millet, Leebaekchal, Manhongchal, Hwangsilchal, Hwanggeumgijang in proso millet and Nampungchal, Hwanggeumchal, DS202, Moktaksusu in sorghum achieved from RDA. In culm length, sowing date of June 26 was the highest in all varieties of foxtail millet, proso millet and sorghum. Sowing date of May 15 showed the highest ear length in foxtail and proso millet, whereas the highest ear length was obtained from sowing date of June 26 in sorghum. In numbers of leaf, sowing date of May 15 showed the highest in all three crops of foxtail millet, proso millet and sorghum. Days from sowing to heading date were reduced in Samdamae, Kyeongkwan1 and Samdachal as sowing date was late. In Hwanggeumjo it was reduced from the sowing date from May 15 to June 26, but it was same days was taken between June 26 and July 13 sowing date. Days from sowing to heading date of four varieties in proso millet were reduced as sowing date was late. Days from sowing to heading date in sorghum were reduced as sowing date was late, whereas it was increased the $4^{th}$ sowing date of July 13. There were no significant differences in growth and yield characteristics between mulching and non-mulching in four varieties of foxtail millet, proso millet and sorghum with four varieties. The highest grain numbers per panicle, 1000 grain weight and yield per 10a were obtained from sowing date of June 26 in four varieties of foxtail millet, proso millet and sorghum. In sowing date of July 13, all varieties of foxtail millet, proso millet and sorghum were not able to be ripened because of late sowing except Hwnaggeumjo, Manhongchal and Hwanggeumgijang.

The Early Prognosis of Burn Patients with Elevated Initial Arterial Carboxyhemoglobin Level (초기 동맥혈 Carboxyhemoglobin 농도가 높았던 화상 환자들의 예후지표에 관한 연구)

  • Choi, Chang Soon;Kim, Cheal Hong;Kim, Keun Sook;Lee, Tae-Yu;Chung, Youn Son;Eom, Kwang Seok;Park, Young Bum;Jang, Seung Hun;Kim, Dong Gyu;Park, Myung Jae;Lee, Myung Goo;Hyun, In-Gyu;Jung, Ki-Suck;Kim, Jong Hyun
    • Tuberculosis and Respiratory Diseases
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    • v.55 no.2
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    • pp.188-197
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    • 2003
  • Background : Smoke inhalation injury is an important determinant of mortality in burn patients. The early detection of inhalation injury in burn patients is important because the incidence of respiratory failure after inhalation injury was known to be high, with hypoxemia, pneumonia, and prolonged ventilatory support being commonplace. Acute carbon monoxide poisoning was one feature of smoke inhalation. The purpose of our study were to investigate the clinical characteristics of burn patients whose initial arterial carboxyhemoglobin (COHb) level had been elevated, to assess the clinical impact of COHb for smoke inhalation injury. Methods : Among 1,416 burn patients had been admitted at our institution from August 1, 2001 to July 31, 2002, 39 patients whose initial arterial COHb level have been more than 5% were included. We compared clinical scoring system for inhalation injury, percent total body surface area (%TBSA) burn, initial chest X-ray findings, APACHE II scores and SAPS II scores between survivors (n=27) and non-survivors (n=12) retrospectively. Results : COHb level were 9.7(5.71% and 10.3(8.81% in survivors and in non-survivors (p>0.05). Mean %TBSA burn of survivors and non-survivors were $16.6{\pm}17.8%$ and $60.7{\pm}28.8%$ (p<0.001). We did not find any difference in clinical scoring system, initial chest X-ray findings in survivors and in non-survivors. But %TBSA burn, APACHE II and SAPS II scores were high in non-survivors than in survivors significantly. Important factors associated with death were %TBSA burn, APACHE II scores, SAPS II scores, and the most important factor in predicting mortality was %TBSA burn. Conclusion : Burn patients with elevated initial arterial COHb level showed poor prognosis, but further study may be performed to know that the effect of COHb on prognosis in burn patients accompanying smoke inhalation.

Management Guidelines and the Structure of Vegetation in Natural Monuments Koelreuteria Paniculata Community (천연기념물 모감주나무군락의 식생구조와 관리제언)

  • Shin, Byung Chul;Lee, Won Ho;Kim, Hyo Jeong;Hong, Jeum Kyu
    • Korean Journal of Heritage: History & Science
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    • v.43 no.1
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    • pp.100-117
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    • 2010
  • This study analyzed vegetation structure of natural monuments Koelreuteria paniculata community in search of a conservation and management plan. Plant sociological analysis of Koelreuteria paniculata community indicates that it can be classified into Achyranthes japonica subcommunity and Rhodotypos scandens subcommunity and Trachelospermum asiaticum var. intermedium subcommunity. While Koelreuteria paniculata community of Ahnmyeondo is composed of sub tree layer and herb layer, those of Pohang and Wando are composed of tree layer, Sub tree layer, shrub layer, herb layer. The results of tree vitality analysis showed that those in Ahnmyeondo appeared to be relatively low when compared to those in Pohang and Wando-gun. This can be understood in two different aspects: disease and insects vulnerability due to a relatively simple structure and lack of competitive species, and decreased vitality / natural branch losses due to crown competition arising from high density. The result of soil characteristics analysis showed that soil texture, soil pH, organic matter, $p_2O_5$, exchange positive ion were sufficient for tree growth while total nitrogen was not, so that discretion would be needed for fertilizer application. As there were damages of disease and inscet, but only for 10~15% of the entire area; it still requires consistent preconsideration. The study suggests the management methods for preservation of Koelreuteria paniculata community. First, securing designated areas is necessary in order to minimize environment deterioration due to surrounding development. Especially, for sections with decreased areas, expansion of designated areas through land purchase should also be considered. Second, artificial interference may affect the livestock. Therefore, monitoring of artificial interference is necessary, based on which protection projects must be conducted. Third, from analysis of young plants which influence the maintenance mechanisms of Koelreuteria paniculata community, a decrease compared to the prior year was observed; investigation is needed. Therefore, an active management policy through status examination of livestock such as germination and young plants is necessary.

Development of Embedded Board for Integrated Radiation Exposure Protection Fireman's Life-saving Alarm (일체형 방사선 피폭 방호 소방관 인명구조 경보기의 임베디드 보드 개발)

  • Lee, Young-Ji;Lee, Joo-Hyun;Lee, Seung-Ho
    • Journal of IKEEE
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    • v.23 no.4
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    • pp.1461-1464
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    • 2019
  • In this paper, we propose the development of embedded board for integrated radiation exposure protection fireman's life-saving alarm capable of location tracking and radiation measurement. The proposed techniques consist of signal processing unit, communication unit, power unit, main control unit. Signal processing units apply shielding design, noise reduction technology and electromagnetic wave subtraction technology. The communication unit is designed to communicate using the wifi method. In the main control unit, power consumption is reduced to a minimum, and a high performance system is formed through small, high density and low heat generation. The proposed techniques are equipment operated by exposure to poor conditions, such as disaster and fire sites, so they are designed and manufactured for external appearance considering waterproof and thermal endurance. The proposed techniques were tested by an authorized testing agency to determine the effectiveness of embedded board. The waterproof grade has achieved the IP67 rating, which can maintain stable performance even when flooded with water at the disaster site due to the nature of the fireman's equipment. The operating temperature was measured in the range of -10℃ to 50℃ to cope with a wide range of environmental changes at the disaster site. The battery life was measured to be available 144 hours after a single charge to cope with emergency disasters such as a collapse accident. The maximum communication distance, including the PCB, was measured to operate at 54.2 meters, a range wider than the existing 50 meters, at a straight line with the command-and-control vehicle in the event of a disaster. Therefore, the effectiveness of embedded board for embedded board for integrated radiation exposure protection fireman's life-saving alarm has been demonstrated.

Spatial Patterns and Temporal Variability of the Haines Index related to the Wildland Fire Growth Potential over the Korean Peninsula (한반도 산불 확장 잠재도와 관련된 Haines Index의 시.공간적 특징)

  • Choi Cwang-Yong;Kim Jun-Su;Won Myoung-Soo
    • Journal of the Korean Geographical Society
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    • v.41 no.2 s.113
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    • pp.168-187
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    • 2006
  • Windy meteorological conditions and dried fire fuels due to higher atmospheric instability and dryness in the lower troposphere can exacerbate fire controls and result in more losses of forest resources and residential properties due to enhanced large wildland fires. Long-term (1979-2005) climatology of the Haines Index reconstructed in this study reveals that spatial patterns and intra-annual variability of the atmospheric instability and dryness in the lower troposphere affect the frequency of wildland fire incidences over the Korean Peninsula. Exponential regression models verify that daily high Haines Index and its monthly frequency has statistically significant correlations with the frequency of the wildland fire occurrences during the fire season (December-April) in South Korea. According to the climatic maps of the Haines Index created by the Geographic Information System (GIS) using the Digital Elevation Model (DEM), the lowlands below 500m from the mean sea level in the northwestern regions of the Korean Peninsula demonstrates the high frequency of the Haines Index equal to or greater than five in April and May. The annual frequency of the high Haines Index represents an increasing trend across the Korean Peninsula since the mid-1990s, particularly in Gyeongsangbuk-do and along the eastern coastal areas. The composite of synoptic weather maps at 500hPa for extreme events, in which the high Haines Index lasted for several days consecutively, illustrates that the cold low pressure system developed around the Sea of Okhotsk in the extreme event period enhances the pressure gradient and westerly wind speed over the Korean Peninsula. These results demonstrate the need for further consideration of the spatial-temporal characteristics of vertical atmospheric components, such as atmospheric instability and dryness, in the current Korean fire prediction system.

Study of the Value of National Cultural Heritage in the Gaetaesa Temple Site, Nonsan and the Establishment of an Integrated Maintenance Plan (논산 개태사지의 국가문화재적 가치 및 종합정비방안 수립에 관한 연구)

  • Seo, Jung-young
    • Journal of the Korean Institute of Landscape Architecture
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    • v.47 no.2
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    • pp.76-87
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    • 2019
  • This study aims to analyze the status of the Gaetaesa Temple Site in Nonsan and the value of national cultural heritage associated with it, to work towards gaining the acceptance criteria to become state-designated cultural property and to propose a plan for comprehensive maintenance, a plan for the promotion of the project and a plan for the management and operation. The Gaetaesa Temple Site in Nonsan has unprecedented advancements, and the condition of the remains are relatively good. It would be necessary to conduct digging/excavation surveys continuously in the future and ensure the dignity of the Gaetaesa Temple Site in Nonsan as a cultural asset. In addition, the Gaetaesa Temple Site has excellent historical and cultural values as treasure-class cultural heritage. Most temples had treasures taken out of them, so it is necessary to designate this site as a state-designated cultural property instead of a municipality-designated cultural heritage site, and to manage it systematically. Accordingly, this study investigated the history and historical facts about the Gaetaesa Temple Site in Nonsan through the analysis of literature, including old documents, old maps, related academic papers and books, and referred to the results of digging/excavation surveys, conducted up to six times since the first excavation survey conducted in 1986, in order to understand the status of the remains, ruins and the building sites excavated at the Gaetaesa Temple Site in Nonsan. In addition, this study analyzed the values of the Gaetaesa Temple Site in Nonsan, dividing them into the remains, relics and ruins, and set up the scope of the Gaetaesa Temple Site in Nonsan, the cultural property area (designated and protected areas) and the acceptance criteria for the construction work in the historical and cultural environment preservation area. This study proposed a plan for the comprehensive maintenance of the Gaetaesa Temple Site in Nonsan, a plan for the promotion of the project and a plan for the management and operation. It is necessary to carry out ongoing excavation investigations and to reflect the opinions of the residents for the purchase of land, to supplement the comprehensive maintenance plan, business promotion and management plans, and step-by-step business plans should be established in detail.

A Study on the Structure and Function of the Underground Storage Facility in Baekje (백제 지하저장시설(地下貯藏施設)의 구조와 기능에 대한 검토)

  • Shin, Jong-Kuk
    • Korean Journal of Heritage: History & Science
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    • v.38
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    • pp.129-156
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    • 2005
  • Increasing discovery cases of underground storage facilities made of earth, wood, or stone are being reported from the recent excavation survey of the Baekje relics. Accordingly, the purpose of this study is to examine the structure and function of the underground storage facilities of Baekje following a classification made by the type and building method as follows: plask shape, wooden box shape, and stone box shape. The plask shape storage is the most representative underground storage of Baekje that has been found in numerous relics more than 600 sets around Hangang(Han River) and Geumgang(Geum River) from the Hansung period to Sabi period in Baekje Dynasty. It is a historical artefact as a part of the unique storage culture of Baekje around Hangang and Geumgang from the 3rd to 7th Century. Considering its structure and the example of Chinese one, it might had been used for a long-term storage of grains and various other items including earth wares. The storage facility in wooden box shape and stone box shape are found mostly in the relics Of Sabi period. Thus it might had taken some functions of the storage in traditional pouch shape which had decreased after the 6th Century. In particular, the wooden box shape and stone box shape storage required enormous labor force to build owing to their structure and building method. Thus, they were considered to had been used for official purposes in province fortress and citadel artefact. The wooden box shape storage facility is classified into flat rectangular type and square type based on the structure, and into Gagu type(架構式) and Juheol type(柱穴式) based on the building method. It might had been decided according to the geography and geological feature of the place where the storage was to be built. Considering the examples of Gwanbuk-ri relics and Weolpyong-dong relics, the wooden box shape storage facility might had been used for various items depending on the needs, including foods such as fruits and essential provisions at the military base. Considering the long-term food storage, the examples in Japan, and the functional characteristics of the underground storage facility, there is a possibility that the wooden and stone box shape storage facilities had been built so as to safely store important items in case of fire. This study is only a rudimentary examination for the storage facility in Baekje. Thus further studies are to be made specifically and comprehensively on the comparison with other regions, distribution pattern, discovered relics and artefacts, and functions.

A Study on the Present Condition and Improvement of Cultural Heritage Management in Seoul - Based on the Results of Regular Surveys (2016~2018) - (서울특별시 지정문화재 관리 현황 진단 및 개선방안 연구 - 정기조사(2016~2018) 결과를 중심으로 -)

  • Cho, Hong-seok;Suh, Hyun-jung;Kim, Ye-rin;Kim, Dong-cheon
    • Korean Journal of Heritage: History & Science
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    • v.52 no.2
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    • pp.80-105
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    • 2019
  • With the increasing complexity and irregularity of disaster types, the need for cultural asset preservation and management from a proactive perspective has increased as a number of cultural properties have been destroyed and damaged by various natural and humanistic factors. In consideration of these circumstances, the Cultural Heritage Administration enacted an Act in December 2005 to enforce the regular commission of surveys for the systematic preservation and management of cultural assets, and through a recent revision of this Act, the investigation cycle has been reduced from five to three years, and the object of regular inspections has been expanded to cover registered cultural properties. According to the ordinance, a periodic survey of city- or province-designated heritage is to be carried out mainly by metropolitan and provincial governments. The Seoul Metropolitan Government prepared a legal basis for commissioning regular surveys under the Seoul Special City Cultural Properties Protection Ordinance 2008 and, in recognition of the importance of preventive management due to the large number of cultural assets located in the city center and the high demand for visits, conducted regular surveys of the entire city-designated cultural assets from 2016 to 2018. Upon the first survey being completed, it was considered necessary to review the policy effectiveness of the system and to conduct a comprehensive review of the results of the regular surveys that had been carried out to enhance the management of cultural assets. Therefore, the present study examined the comprehensive management status of the cultural assets designated by the Seoul Metropolitan Government for three years (2016-2018), assessing the performance and identifying limitations. Additionally, ways to improve it were sought, and a DB establishment plan for the establishment of an integrated management system under the auspices of the Seoul Metropolitan Government was proposed. Specifically, survey forms were administered under the Guidelines for the Operation of Periodic Surveys of National Designated Cultural Assets; however, the types of survey forms were reclassified and further subdivided in consideration of the characteristics of the designated cultural assets, and manuals were developed for consistent and specific information technologies in respect of the scope and manner of the survey. Based on this analysis, it was confirmed that 401 cases (77.0%) out of 521 cases were generally well preserved; however, 102 cases (19.6%) were found to require special measures such as attention, precision diagnosis, and repair. Meanwhile, there were 18 cases (3.4%) of unsurveyed cultural assets. These were inaccessible to the investigation at this time due to reasons such as unknown location or closure to the public. Regarding the specific types of cultural assets, among a total of 171 cultural real estate properties, 63 cases (36.8%) of structural damage were caused by the failure and elimination of members, and 73 cases (42.7%) of surface area damage were the result of biological damage. Almost all plants and geological earth and scenic spots were well preserved. In the case of movable cultural assets, 25 cases (7.1%) among 350 cases were found to have changed location, and structural damage and surface area damage was found according to specific material properties, excluding ceramics. In particular, papers, textiles, and leather goods, with material properties that are vulnerable to damage, were found to have greater damage than those of other materials because they were owned and managed by individuals and temples. Thus, it has been confirmed that more proactive management is needed. Accordingly, an action plan for the comprehensive preservation and management status check shall be developed according to management status and urgency, and the project promotion plan and the focus management target should be selected and managed first. In particular, concerning movable cultural assets, there have been some cases in which new locations have gone unreported after changes in ownership (management); therefore, a new system is required to strengthen the obligation to report changes in ownership (management) or location. Based on the current status diagnosis and improvement measures, it is expected that the foundation of a proactive and efficient cultural asset management system can be realized through the establishment of an effective mid- to long-term database of the integrated management system pursued by the Seoul Metropolitan Government.