• Title/Summary/Keyword: 연기거리

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A Numerical Study for the Atrium Smoke Control by Fire Shutter and Evacuation (방화셔터를 이용한 아트리움 제연과 피난안전에 관한 수치해석 연구)

  • Jeon, Heung-Kyun;Choi, Young-Sang;Choo, Hong-Lok
    • Fire Science and Engineering
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    • v.24 no.5
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    • pp.50-59
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    • 2010
  • Four fire scenarios, as the cases of fire sizes of 2 MW and 5 MW, and no installation and activation of atrium fire shutter for dormitory building of Daegu 'D college', were developed and fire simulations were run using FDS (ver. 5.5.0) and Pathfinder 2009 programs. By assessing fire and evacuation, the effects of atrium fire shutter and vents on the smoke control of atrium were evaluated and this study also analyzed fire hazard and egress safety for occupants in the dormitory. Fire shutter's preventing smoke transport around atrium was much effective, but smoke layer descended down the design limit of smoke height and kept about 2 m height from the atrium floor in all cases because flow rate through vents was not enough. For the case of 5 MW fire and no fire shutter, fire hazard was higher due to visibility than temperature and allowable egress time to stairwell was short less than 5 seconds for the occupants on the floors of 4F to 7F. For total occupants, egress time out of main doorway was calculated about 136 seconds. It is sure that additional systems improving the performance of smoke control need to be installed for more safe evacuation.

A study on the smoke control performance of the damper exhaust system at FCEV fire in tunnel for small vehicles (소형차 전용터널 내 수소연료전지차 화재시 집중배기방식의 제연성능에 관한 연구)

  • Hong, Seo-Hee;Baek, Doo-San
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.24 no.6
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    • pp.745-756
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    • 2022
  • The road tunnel is a semi-closed space that is blocked on all sides except the entrance and exit, and in the event of a fire, the smoke of the fire spreads longitudinally due to heat buoyancy caused by the fire and air currents that always exist in the tunnel. To solve this problem, smoke removal facilities are installed in road tunnels to secure a safe evacuation environment by controlling the direction of movement of smoke or directly smoking at fire points. In urban areas, the service level of urban roads decreases due to the increase in traffic due to the increase in population, and as a solution, the construction of underground roads in urban areas is increasing. When a fire occurs during hydrogen leakage through TPRD of a hydrogen fuel cell vehicle (FCEV), the fire intensity depends on the amount of leakage, and the maximum fire intensity depends on the orifice diameter of the TPRD. Considering the TPRD orifice diameter of 1.8 mm, this study analyzed the diffusion distance of fire smoke according to the wind speed of the roadway and the opening interval of the large exhaust port when the maximum fire intensity was 15 MW. As a result, it was analyzed that air flow in the tunnel could be controlled if the wind speed of the road in the tunnel was less than 1.25 m/s, and smoke could be controlled within 200 m from the fire if the damper interval was 50 m and 100 m.

A Kinematical Analysis of 205B Motion in Platform Diving (플랫폼 다이빙 종목 205B동작의 운동학적 분석)

  • Lee, Chong-Hoon
    • Korean Journal of Applied Biomechanics
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    • v.18 no.1
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    • pp.53-62
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    • 2008
  • The purpose of this research was to analyze the kinematics of the 205B movement in platform diving. For the experiment, 2 athlete from the national diving team were chosen as the subject and two S -VHS video cameras were used. For this diving players preparing for the olympics participated. It was shown that the mean total took $1.112{\pm}0.12s$. In order to perform better, the divers time must be increased, at take off and rotation must be done high up and the horizontal distance must be shorted to main entrance of the water. To enter the water safely, the jump has to be high, the horizontal speed slow and the vertical speed as fast as possible. At E1 the lower limbs change in speed should decrease and after the rotation begins at E2. At take off, the jump is more important than the rotation for the performance of the dive. At take off, the trunk angular velocity was high, and this was needed to jump high for moment of inertia for rotation because for efficient jumping the upper body has to spread out and increase the height of the center of mass.

Analysis of the Wireless Communication Environment in the Narrowed Residential Space for the Fire fighting Operation (소방작전을 위한 협소거주 공간의 무선 통신 환경 분석)

  • Park, Hyun-Ju;Hong, Sang-Beom;Choi, Hyuk-Jo
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.10 no.3
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    • pp.242-248
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    • 2017
  • Recently, Population has been concentrated in cities due to rapid economic growth. As a result, urban buildings are becoming more dense, high-rise, and diversified. The shape of these urban buildings increases the risk of fire, accidents and crime. The narrow living space has the characteristic of the unchanged floor. In case of a fire, the living space of the narrow residence is large in the damage because the smoke diffusion rate is fast. The radio wave transmittance and transmission distance of wireless communication used in fire fighting operations vary depending on the type of building materials and buildings. Therefore, this paper analyzes the building materials and structural characteristics of the narrow residential space for efficient fire fighting operations. We have developed a communication environment solution for a narrow residential space for the optimal fire fighting operation through the measurement of the radio wave transmittance and the transmission distance of the wireless communication.

The Embody of the Direction Escape Algorithm for Optimization Escape (최적 비상대피로 유도를 위한 방향성 유도 알고리즘 구현)

  • Lee, Ki-Yeon;Kim, Dong-Ook;Kim, Dong-Woo;Mun, Hyun-Wook;Gil, Hyung-Jun;Kim, Hyang-Kon
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.23 no.10
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    • pp.115-120
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    • 2009
  • In this parer, we design the artificial intelligent direction escape light control system to improve/complete the defects of the existing fire fighting system, and sketch an optimum escape guide algorithm for its implementation. It intends to minimize human casualties and injuries by calculating/predicting moving line of the optimum emergency escape, by means of interlocking the sensor and the reception group and analyzing the data of the combustion point and the smoke movement. The optimum escape algorithm is designed by FLOYD algorithm which calculates the shortest distance. It consists of the measuring method which calculates the shortest distance by using hazardous factors for each condition in danger which is judged by the sensor installed in each area.

Study on the Goryeo Sea Route by Seogeung and Aids to Navigation Facility of Goryeo Fire Signal (서긍의 고려항로와 고려 봉수의 항로표지 기능에 관한 연구)

  • Moon, Beom-Sik
    • Journal of Navigation and Port Research
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    • v.43 no.4
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    • pp.243-249
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    • 2019
  • Seonhwa Bongsa Goryeodogyeong written by Seogeung of Song nationality is the most vivid record of sailing in the West Sea of Goryeo. Seogeung who visited Goryeo on a ship sailed from Heuksando to Byeokrando using a fire signal of the islands area. Fire signal was installed in the Goryeo area, was located nearby the sea route at that time, and was marked by smoke during the day and torched at night so that the navigators could identify it 24 hours. In addition, it was installed at the top of the mountain so that the navigators could easily identify it from a distance. Goryeo fire signal is satisfied by qualification of modern aids to navigation and Visual range is checked about 29-39 miles, Luminous intensity of fire signal estimates to approximately 9,105-168,610cd. Therefore, the fire signal of Goryeo was very easy to use and was highly reliable as operated by the nation and its role in aiding navigations facility as an essential for safe navigation.

Derivations of Positive Pressure Condition for Development of Foldable Safe Pathway in Railway Tunnel Fires (철도터널화재용 접이식 대피통로 개발을 위한 양압 조건 도출)

  • Kim, JiTae;Ro, Kyoungchul
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.1
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    • pp.284-289
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    • 2019
  • The Korea Foldable safe pathway system is an evacuation support system to get temporary evacuation route in railway tunnel and large space fires. A prevention smoke screen is unfolded in fires and it is needed to prevent heat and smoke from fire source. Therefore, ventilation system for positive pressure condition is equipped with foldable safe pathway system. Numerical analyses of temperature and pressure distribution with distance from fire source were performed considering fire scenario of new train vehicle. The smoke temperatures did not exceed $200^{\circ}C$ that distance from the fire source was more than 20 m and smoke pressure was reduced with distance from fire source. Maximum smoke pressure was 14 Pa and average pressure was 6 Pa in position of prevention smoke screen. As results, to install foldable safe pathway system, ventilation system is need to maintain 6 Pa positive pressure condition.

Buffer Zones for Non-Target Organisms by Aerial Pesticide Application Around Rice Paddy (벼 재배지의 항공 방제시 비표적 생물에 대한 안전거리)

  • Park, Yeon-Ki;Jin, Yeoung-Duck;Kim, Byung-Seok;Park, Kyung-Hun;Lee, Jea-Bong;Shin, Jin-Sup;Bae, Chung-Han;Lee, Kyu-Seung
    • The Korean Journal of Pesticide Science
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    • v.11 no.1
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    • pp.32-37
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    • 2007
  • The study was carried out to establish buffer zone for the protection of the non-target organisms by aerial pesticide application. The two pesticide combination of 3-way tank-mixing of three pesticides for aerial application, ferimzone tricyclazole SC + BPMC EC + validamycin-A SL and hexaconzole EC + isoprothiolane EC+phenthoate EC were selected for the simultaneous control of key pests on paddy rice as blast, sheath blight, brown planthopper and moth. Aquatic organisms including killifish and loach in the paddy field and nearby water reservoirs were not affected by aerial application of the pesticides. However, all the water flea were killed, when they were exposed 10 m from the aerially sprayed site, while the water flea exposed in 30 m away from the site were not affected. Honeybees within 50 m in the wind direction and 20 m in the opposite wind direction showed a mortality of $7{\sim}100%$. Residues concentration of the pesticides in paddy water were not detectable level after six days from aerial application. Drifting distance of aerially sprayed droplet from the target area was within 30 m in the wind direction and 20 m in the opposite direction. Consequently, it was the buffer zones in the aerial pesticides application for the protection of the non-target organisms should be at least 50 m for aquatic organisms and 100 m for honeybees.

Changes in the Performance Industry Due to Social Distancing : Case Analysis of Online Performance Platforms (사회적 거리두기로 인한 공연산업의 변화 : 온라인공연 플랫폼 사례분석)

  • Kim, Jae-Sung;Han, Kyung-Hoon
    • Journal of Korea Entertainment Industry Association
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    • v.15 no.5
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    • pp.1-17
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    • 2021
  • Social distancing caused a sharp industrial stagnation in the performance industry. Due to the continuous industrial downturn, as well as the livelihoods of many related workers, the outlook for the performance industry has reached a point where it is impossible to foresee the future. As a result of seeking various ways to recover from the continuing industrial stagnation, online concerts drew attention as the most effective alternative. Its development potential was highly evaluated as it could provide a performance culture to consumers while complying with social distancing. This study has value in terms of academic contribution as it slightly suggests a direction for the sustainable development of online performances presented as a breakthrough amid the social and industrial stagnation caused by the pandemic. therefore, this thesis describes the changes in the performance industry due to social distancing, and collects and analyzes examples of online performances by type to illuminate the value of online performances as an industry in the pandemic era and develops them. The possibility was reconsidered and the direction to be taken in the future was suggested. In each type of case, the cases focused on social value did not satisfy the economic value of profit creatiom, and even in the opposite case, if the profit creation was satisfied, the analysis result showed that the social value was not satisfied, and the planning intention of each performance was not satisfied. Accordingly, cases such as satisfying both profit creation and social value were also confirmed. Therefore, the direction for online performances was presented through the improvement of technologies and systems and the commercialization of existing platforms.

Experimental Study on the Interval of Emergency Exits in Long Traffic Tunnels (장대 교통터널의 피난연락갱 설치 간격에 관한 실험적 연구)

  • Yoo Yongho;Yoon Sungwook;Kim Jin;Yoon Chanhoon
    • Tunnel and Underground Space
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    • v.15 no.1 s.54
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    • pp.61-70
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    • 2005
  • The objective of this study was to analyze the smoke movement for the case of fire and to determine the interval between emergency exits in long tunnels. Based on Froude modeling, the 1/50 scaled model tunnel (20 m long) was constructed by acrylic tubes and tests were carried out systematically. From the strong relationship between CO propagation time and distance through the tunnel, it was found that the optimal escaping time was 6 minutes in case of 20MW fire. But, regarding passengers' psychological state under fire, another one minute of delay time should be considered. Therefore, the total escaping time should be estimated by 5 minutes. The interval between the emergency exits for vehicle passengers was calculated by 250 m with respect to the 5 minute of escaping time.