PURPOSES : This study focuses on how quickly emergency alarm facilities recognize a fire, respond to evacuation behavior, and induce appropriate behavior in response to the fire alarm sound by listening to the fire alarm sound from a sound device. METHODS : Prior research on alarm sounds affecting evacuation behavior was identified, and a subjective evaluation of alarm sounds was conducted to study the most appropriate evacuation-inducing behavior for alarm sounds. In the event of a fire, a subjective evaluation of the sound pressure level and frequency analysis of the sound system, which affects the occupants in the building, were conducted to analyze the type of alarm sound and evacuation behavior. RESULTS : As a result of the subjective evaluation of the occupants’ listening risk, there was little cognitive response to the change in sound pressure level according to frequency. It was found that the alarm sound could give a sense of crisis or tension owing to the difference in sound pressure level change according to the change in time difference. CONCLUSIONS : In conclusion, with high sound pressure and large decibel deviation, the evacuation behavior of respondents after education was more active in the wake-up call that made a sound that seemed to be torn.

PURPOSES : This study is conducted to evaluate the development of materials for extinguishing ESS(Energy Storage System) fires in electric vehicles using industrial byproducts. METHODS : Grout containing an appropriate amount of fly ash, silica fume, blast furnace slag powder, and ferronikel slag, which are industrial byproducts, was prepared. The fluidity, stress, and mechanical properties were evaluated in accordance with standard test methods. RESULTS : The fluidity of the materials used for the evolution of ESS fires differed depending on the material of the industrial byproducts. In the case of blast furnace slag, its fluidity is low owing to viscosity even when it content is high, and the use of ferronikelsrag is shown to be suitable for the evolution of ESS fires in fluidity and curing tests. CONCLUSIONS : Fire-extinguishing materials using industrial byproducts require a long curing time but exhibit the fluidity required for ESS fire extinguishment. In particular, the curing and fluidity of Peronikel slag and fly ash are suitable for ESS fire extinguishing.

건축물은 사용자의 부주의, 전기적, 기계적 요인 등에 의해 화재가 발생할 수 있고, 화재 발생 시 각 재료의 특성에 따라 강성 및 강도가 감소하여 구조 성능이 저하될 수 있다. 이러한 상황에서 적절 한 성능 복구가 되지 않으면 후에 지진 등의 큰 하중이 가해질 때 건축물 붕괴 등 치명적인 피해가 발생할 수 있다. 현재 내화성능을 높이는 방법으로 내화피복을 사용하는 등 수동적인 방법에 머물러 있으며, 꾸준한 유지관리 등이 필요하다는 단점이 있다. 따라서 변형 후 열을 가하면 원래의 형상으로 돌아가는 성질을 가진 형상기억합금을 사용하여 콘크리트 보를 보강하고, 화재 시, 화재 후에 프리스 트레스트 콘크리트와 유사한 방식으로 콘크리트에 압축응력을 발생시켜 구조 성능을 향상시킬 수 있 는지 ANSYS 구조해석 프로그램을 통해 그 효과를 확인해보고자 한다.

In this paper, as there are many cases of fires occurring due to the failure or inoperability of the thermostat of electronic products, the purpose is to test and analyze the risks and probabilities through fire cases and reproduction experiments, and suggest countermeasures. Among electronic products, water purifiers are composed of a refrigerant system with a compressor to make cold water, a heating device to make hot water, and an electric device used as an energy source. Due to the nature of the water purifier manufacturing, these devices are subject to a lot of moisture and dust. etc. exist in large quantities and use electrical energy, so there is a possibility of fire due to short circuit in the wire, electrical abnormal overheating (tracking phenomenon) in the thermostat, electronic board, starting relay, etc., and overheating of the heating device (Band Heater). there is. Therefore, in order to prevent fires from these devices, a system to remove foreign substances inside the water purifier is necessary, the use of heat-resistant (fire-resistant) wires for electrical devices is essential, and the use of non-combustible materials (semi-combustible materials) for each part is necessary to prevent fire. The risk must be eliminated through prevention and combustion expansion prevention devices.

In recent years the tunnel construction is increasing worldwide because of development of science and technology and increasing of transportation demand. Tunnels are complex structures normally rectangular cross section or semicircular and constructed to connect between different sections of roads. Because of the importance, the construction and extension of road tunnels are also continuously increasing along with the development. According to data from the Korea Expressway Corporation, the number of road tunnels, which was 1,332 in 2010, increased rapidly by about 2.1 times over 10 years to a total of 2,742 in 2020. The extension of road tunnels is also on the trend of increasing, with a total of 945 km in 2010 reaching 2,157 km in 2020. The benefits of a double-deck tunnel are emphasized, particularly in terms of construction cost and convenience. This tunnel design incorporates a central slab, dividing the tunnel into upper and lower spaces. The versatility of a double-decker tunnel is evident in its ability to accommodate various uses for both levels. For instance, the upper level can function as vehicle roads, while the lower level can be designated for train tracks. In this study, the effect of RWS and modified hydrocarbon fire curve was applied to the concrete tunnel bracket through simulation to analyze the temperature after the fire occurrence.

PURPOSES : Carbon dioxide (CO2) is a cheaper and easier to installer fire suppressant than other extinguishing gases and is easy to install, but extinguishes fires by is suffocation. As a result, suffocation accidents continue to occur in facilities equipped with CO2 fire-extinguishing facilities, Emission standards have yet to be established. This study aims to address the issue. METHODS : To effectively remove CO2 emitted from installed systems, we reviewed and analyzed previous related research and existing international standards. RESULTS : In protected areas where CO2 fire-extinguishing systems are installed, emission facilities should discharge the emitted CO2 before it enters the protected spaces. CO2 sensors can determine whether safe entry is possible or whether respirators are required. CONCLUSIONS : This study presented a specific installation method for emission facilities capable of actively discharging CO2. Applying this method is expected to contribute to improving safety in facilities equipped with CO2 fire-extinguishing facilities.

The seismic separation joint is an important device that absorbs vibration displacement from earthquake shock and protects fire extinguishing pipes and various utility pipes. In this study, the mechanical behavior occurring in U-typed and V-typed seismic separation joint was analyzed according to the length of the bellows, the length of the elbow straight pipe, and the open angle. As a result, as the length of the bellows increased, the stress and natural frequency decreased. In addition, as the length of the elbow straight pipe increased, the stress tended to decrease in the case of forced displacement in the vertical direction. As the open angle increased, the stress in the case of forced displacement in the left and right directions increased.

This study was conducted to analyze the effects of stand density on fire fuel (FF) changes in a Chamaecyparis obtusa forest. The study site was located in Mt. Munsu in Jeollabuk-do and consisted of a control, 30% thinning treatment (LT), and 50% thinning treatment (HT). Three-year-old seedlings were planted at a density of 3,000 trees ha-1 in 1976, and thinning was carried out in 2000. FF production was measured every 2 months by installing 3 circular litter traps 1.2 m above the ground. Litter bags containing 5 g of each leaf and branch were made and buried in the organic layer to investigate the FF decomposition rate. The decay constant was calculated after 18 months. FF accumulation was measured by collecting dry-weight organic matter from each plot using a square frame (0.09 m2) in September 2018. The FF production in LT and HT was significantly lower than that of the control (P<0.001). The leaf decay constant for HT was significantly lower than that of the control (P<0.05). The FF accumulation in HT was significantly lower than that of the control (P<0.01), but LT was not significantly different from the control. The results of this study showed that thinning decreased FF production.

The purpose of this study is to identify psychological anxiety factors related to firefighters' field activities and suggest improvement measures. To investigate the actual status of psychological anxiety factors, a survey was conducted on approximately 3,500 current firefighters, and the responses of 505 people who participated in the survey were analyzed. As a research method, frequency analysis and cross-analysis were conducted according to the general characteristics of the participants to determine the actual level of psychological anxiety in each work field and the results were analyzed. As a result of the analysis, it was statistically confirmed that firefighters feel a lot of psychological burden due to legal and institutional inadequacies during dispatch, return, or field activities, and frequent friction with civil servants is also a major cause of psychological anxiety. Therefore, based on the results of this study, it is proposed to establish a permanent legal support team in each city and province, designate and operate a hospital dedicated to psychological treatment, and establish a special provision for traffic accidents during the return of fire trucks so that firefighters can concentrate on their duties without psychological anxiety. do.

This study aims to verify the impact of a metaverse-based safety education program on the fire safety awareness of elementary school students. Utilizing the National Fire Agency's 119 metaverse program, an educational program was implemented for two months, and the experimental group was examined using paired-sample t-tests, while comparisons with the control group were made using independent-sample t-tests. The results revealed statistically significant differences between the experimental and control groups in the area of fire prevention. Although no statistically significant differences were observed over time within each group, the overall average scores for the entire class improved across all areas. Based on these findings, the effectiveness of metaverse-based safety education is suggested; however, a significant difference compared to traditional education was not detected. The study concludes by exploring implications for considerations in the implementation of metaverse safety education in the future.

Human and material damage can be reduced if the risk is evaluated by engineering analysis of fire combustion products, smoke concentration, and smoke movement speed in the event of a fire in apartment houses and officetels. In this study, a lot of research on related safety evaluation in the basement needs to be studied and reflected in design, so experimental research was conducted to analyze the flow of smoke through computer simulation and provide analysis data through evacuation safety evaluation. First of all, the five-story underground parking lot subject to simulation has a large floor area, which is advantageous for improving evacuation safety performance, but it uses temperature detectors to increase detection time and fire spread speed. Second, it was analyzed that the evacuation time at all evacuation ports did not exceed the evacuation time, and as the time from the start of evacuation to the evacuation time was 216.9% compared to the travel time, it was evaluated that the safety performance of the evacuation was secured. Third, the above simulation results are a comprehensive safety evaluation based on the non-operation of fire extinguishing facilities in the fire room to increase safety, which means that smoother evacuation safety performance can be secured by linking fire extinguishing facilities.

Combat-armored vehicles were equipped with an automatic-fire-extinguishing system to ensure the safety of the crew and vehicle from fires on the vehicle. When a fire was occurred, the automatic-fire-extinguishing system automatically detects the fire through sensors and detection lines, sprays a fire extinguisher, and notifies the crew visually and audibly. Recently, there had been cases of automatic-fire-extinguishing systems malfunction on combat-armored vehicles. In this study, in order to resolve the automatic-fire-extinguisher's malfunction phenomenon, ground noise and inter-circuit noise generated from the fire detection line were identified, and the resistance connected on the circuit was revised to remove noise. As a result of resistance revision, the noises was eliminated and the electromotive force difference between input circuits was made constant, thereby improving the malfunction of the automatic-fire-extinguishing system. By applying the result, it was confirmed that the control device sensed a temperature similar to the actual temperature on actual vehicles, and it was confirmed that the automatic-fire-extinguishing system's malfunction phenomenon was not founded in the field vehicles after then.

PURPOSES : This study provides fundamental information on the temperature variations in tunnel structures during severe fire events. A fire event in a tunnel can drastically increase the internal temperature, which can significantly affect its structural safety. METHODS : Numerical simulations that consider various fire conditions are more efficient than experimental tests. The fire dynamic simulator (FDS) software, based on computational fluid dynamics (CFD) and developed by the National Institute of Standards and Technology, was used for the simulations. The variables included single and multiple accidents involving heavy goods vehicles carrying 27,000 liters of diesel fuel. Additionally, the concrete material characteristics of heat conductivity and specific heat were included in the analysis. The temperatures of concrete were investigated at various locations, surfaces, and inside the concrete at different depths. The obtained temperatures were verified to determine whether they reached the limits provided by the Fire Resistance Design for Road Tunnel (MOLIT 2021). RESULTS : For a fire caused by 27,000 liters of diesel, the fire intensity, expressed as the heat release rate, was approximately 160 MW. The increase in the carrying capacity of the fire source did not significantly affect the fire intensity; however, it affected the duration of the fire. The maximum temperature of concrete surface in the tunnel was approximately 1400 ℃ at some distance away in a longitudinal direction from the location of fire (not directly above). The temperature inside the concrete was successfully analyzed using FDS. The temperature inside the concrete decreased as the conductivity decreased and the specific heat increased. According to the Fire Resistance Design for Road Tunnel (MOLIT 2021), the internal temperatures should be within 380 ℃ and 250 ℃ for concrete and reinforcing steel, respectively. The temperatures were found to be approximately 380 ℃ and 100 ℃ in mist cases at depths of 5 cm and 10 cm, respectively, inside the concrete. CONCLUSIONS : The fire simulation studies indicated that the location of the maximum temperature was not directly above the fire, possibly because of fire-frame movements. During the final stage of the fire, the location of the highest temperature was immediately above the fire. During the fire in a tunnel with 27,000 liters of diesel, the maximum fire intensity was approximately 160 MW. The capacity of the fire source did not significantly affect the fire intensity, but affected the duration. Provided the concrete cover about 6 cm and 10 cm, both concrete and reinforcing steel can meet the required temperature limits of the Fire Resistance Design for Road Tunnel (MOLIT 2021). However, the results from this study are based on a few assumptions. Therefore, further studies should be conducted to include more specific numerical simulations and experimental tests that consider other variables, including tunnel shapes, fire sources, and locations.

Solenopsis invicta, known as the red imported fire ant, is an insect native to South America. This species was unintentionally introduced into Australia, New Zealand, several Asian countries, Caribbean countries, and the United States. It shows a high survival rate and settlement potential in human-habitable and non-living areas such as tropical rainforests, disturbed areas, deserts, grasslands, and roads. In Korea, invasions of red fire ants have been reported every year since 2017, and two invasions were discovered in 2023. Quarantine agency analyzing the haplotype and colony social type of S. invicta for surveillance and control. Population genetic analysis using Microsatellite Alleleic data of 66 loci to trace the origin of the invasion. Through research cooperation with the United States Department of Agriculture (USDA), we have received samples and expanded our genetic information database. This study analyzed genetic differences between 15 invasive populations and 44 reference groups. As a result of microsatellite analysis, the domestic invasive population showed a genetic structure similar to those in Guangzhou, China, and Florida, USA.