• Fire Science and Engineering
• /
• v.23 no.2
• /
• pp.13-19
• /
• 2009

This study is related with fire risk assessment for occupant of the area adjacent to not enclosed atrium through the computer modeling and application of enhanced fire protection systems depending on the result. Fire scenario is intended to evaluate the impact of a fire from atrium base within the corridor adjacent to the atrium and to compare with egress time depending on the warning system. The major purpose of this study is to figure out fire life safety for occupant adjacent to atrium through the computer simulation and to suggest alternative option in case the occupant safety is not guaranteed.

• Fire Science and Engineering
• /
• v.25 no.1
• /
• pp.1-6
• /
• 2011

An evacuation simulation was carried out to confirm evacuation efficiency for stair width and problems in calculation of occupant load for high-rise buildings. The evacuation time and number of evacuated persons from a 39 story condominium-mercantile building were calculated by using Simulex for stair widths of 1.2 m, 1.5 m, and 1.8 m. The total occupant load based on the Korean code was higher than the number of actual residents by 2.3 times, and that based on the NFPA 101 Life Safety Code by 2.6 times, respectively. For the occupant load based on the Korean code, smaller stair width resulted in lower evacuation efficiencies due to bottlenecks in egress. For the actual residents and NFPA code-based occupant load, a high evacuation efficiency and negligible effects of the stair width on evacuation efficiency were confirmed. It was shown that there was a bottleneck even at the stair width of 1.8 m for the Korean code-based occupants, while the stair width of 1.2 m provided safe egress to the actual residents or NFPA code-based occupants. This recommended further studies on possibility of lowering the level of the Korean code in calculation of the occupant load.

• Fire Science and Engineering
• /
• v.26 no.3
• /
• pp.1-7
• /
• 2012

When the subway car stop on track, passengers have to overcome a height of 1.2 m from floor level of the subway car to the level of track for evacuation. In this experiments, participates in the group of twenties or under ages were rapidly jumping down from the subway car. However, Most elderly group were not easy to overcome the height without help of others and some of them were fell and injured. In case of merging flows, the flow rate of the group of twenties was lower than the other cases. If fire occurred in the train and train stopped in the tunnel, it will be needed a lot of total evacuation time because of the heigh difference and wall effect from subway car to outside.

• The Journal of the Convergence on Culture Technology
• /
• v.10 no.2
• /
• pp.201-208
• /
• 2024

In this study, we investigated whether the evacuation time according to the exit installation standards specified in the building code during a food factory fire is compatible with the evacuation time based on the performance-based design specified by the fire department, in order to determine if evacuation safety is ensured. We used the Pathfinder program to confirm the evacuation time, and experimented with three scenarios for exit installation standards towards the outside of the building: 60m, 80m, and 100m. The target building in the experiment corresponded to the building code's exit installation standard of 100m from each dwelling. The experimental results showed tt in the cases of 80m and 100m, ASET exceeded RSET, indicating tt evacuation safety was not ensured, while in the case of 60m, evacuation safety was maintained. Through this study, it was confirmed tt even when the exit installation standards towards the outside of the building are met, evacuation safety may not be guaranteed.

• Journal of Mechanical Science and Technology
• /
• v.16 no.11
• /
• pp.1485-1496
• /
• 2002

In order to investigate the fire-induced smoke movement in a three-dimensional room with an open door, numerical and experimental study was performed. The center, wall, and corner fire plumes for various sized fires were studied experimentally in a rectangular pool fire using methanol as a fuel. The numerical results from a self-developed SMEP (Smoke Movement Estimating Program) field model were compared with experimental results obtained in this and from literature. Comparisons of SMEP and experimental results have shown reasonable agreement. As the fire strength became larger for the center fires, the air mass flow rate in the door, average hot layer temperature, flame angle and mean flame height were observed to increase but the doorway-neutral-planeheight and the steady-state time were observed to decrease. Also as the wall effect became larger in room fires, the hot layer temperature, mean flame height, doorway-neutral-planeheight and steady-state time were observed to increase. In the egress point of view considering the smoke filling time and the early spread of plume in the room space, the results of the center fire appeared to be more dangerous as compared with the wall and the corner fire. Thus it is necessary to consider the wall effect as an important factor in designing efficient fire protection systems.

• Steel and Composite Structures
• /
• v.18 no.2
• /
• pp.375-394
• /
• 2015

This paper presents the results of four long-term experiments carried out to investigate the time-dependent behaviour of composite floor slabs with particular attention devoted to the development of non-uniform shrinkage through the slab thickness. This is produced by the presence of the steel deck which prevents moisture egress to occur from the underside of the slab. To observe the influence of different drying conditions on the development of shrinkage, the four 3.3 m long specimens consisted of two composite slabs cast on Stramit Condeck $HP^{(R)}$ steel deck and two reinforced concrete slabs, with the latter ones having both faces exposed for drying. During the long-term tests, the samples were maintained in a simply-supported configuration subjected to their own self-weight, creep and shrinkage for four months. Separate concrete samples were prepared and used to measure the development of shrinkage through the slab thickness over time for different drying conditions. A theoretical model was used to predict the time-dependent behaviour of the composite and reinforced concrete slabs. This approach was able to account for the occurrence of non-uniform shrinkage and comparisons between numerical results and experimental measurements showed good agreement. This work highlights the importance of considering the shrinkage gradient in predicting shrinkage deformations of composite slabs. Further comparisons with experimental results are required to properly validate the adequacy of the proposed approach for its use in routine design.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.40 no.10
• /
• pp.43-50
• /
• 2003

This paper describes the optical resource reservation protocol for Optical Burst Switching(OBS) networks, in which the burst sending time and the burst size at an ingress node are determined by the available resources between the ingress and egress nodes. Our scheme attempts to improve the burst contention resolution and optical channel utilization. We analyze the performance of the optical resource reservation protocol by using NS2 simulator.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2017.05a
• /
• pp.50-51
• /
• 2017

The Urban-type building is an building that it relaxed the construction standard and subsidiary facility standard. The most of the urban-type buildings are pilotis, the main case of representing these building's fire risk is the Uijeongbu fire this study investigated to piloti urban type housing risk on the basis of Uijeongbu fire, and we checked structural problem that unable to escape from the rooftop inside the piloti. also, there was confirmed limit to the evacuation of the occupants because the smoke was rapidly transferred to the top layer through inside the electric duct. and when we analyzed smoke flow use of Fire simulation, it was confirmed Available Safety Egress Time that is four minutes of CO.

• Journal of Korean Society of Transportation
• /
• v.22 no.6
• /
• pp.47-54
• /
• 2004

Recently, a large reduction in domestic aviation demand had roughly shown in the range between 34% and 75% in east central and western corridor of Korea. The reasons for the drop in air traffic demand were the provisioning of several new highway serveces and the national economic difficulties. Since April 2004, moreover, the Korea Train Express(KTX) was operated between Seoul and Daegu in the first phrase of 293Km in KTX operational distance and 258Km in air route distance. The operation of KTX significantly impacted air traffic volume, particularly on the overlapped air routes with KTX routes. This study analyzed the effects on air traffic demand in accordance with the opening of KTX by applying the Stated Preference (SP) survey method, the survey conducted prior to 8 months of the KTX initiative. Also, the comparison of the decreased demand forecast by SP analysis and actual revealed traffic volume during two months service after inauguration of KTX was conducted. The Seoul-Daegu route was analysed using the 3 variables considered access and egress time, fare rate, operational frequency. The result obtained from the analysis showed that air users would be preferred only 14%. Comparatively, however, the actual revealed air passengers after the opening KTX were remained 28%, The less "decreased demand" was caused by the instability of the KTX's operation in the initial stage. Therefore, small numbers of passenger were preferable to airservices rather than high speed railroad service.

• Fire Science and Engineering
• /
• v.26 no.4
• /
• pp.48-54
• /
• 2012

In order to study on the evacuation risk when connate fires caused by vertical fire spread of the exterior occurs, the egress simulations based on the relevant scenarios has carried out. As a result of it, ASET (permitted evacuation time) was reached in between 550 to 650 seconds in entire floors after vertical smoke spread from fire of combustible exteriors. In particular, ASET was 358 seconds in the first floor, 490 seconds in the six floor and 473 seconds in the tenth floor. In addition, five floors of all levels, the 1st floor, the 6th floor and the 28th floor ~30th floor, show RSET (minimum evacuation time) which is bigger than ASET as evacuation risk. This result presents occupants in high rise buildings with more than 15 floors might not be able to egress of them using staircases due to huge population attempting to evacuate simultaneously. Particularly, 699 people in the upper levels by smoke from the first floor are having difficulty escaping this building since ASET on the first floor adjacent to the ignition point was 358 seconds which is relatively reached fast. Considering a prevention method of the fire and smoke spread, architects have to use non-combustible exterior in the building's facade to be required as an active fire protection system.