• Fire Science and Engineering
• /
• v.19 no.1 s.57
• /
• pp.80-86
• /
• 2005

In this study effects of the natural wind and the forced smoke ejection by operating the exhaust fan are studied numerically to examine the flow characteristics of the smoke and heat generated from a fire on the platform of an underground subway station. Three different situations, including 1) the case with no natural wind and no exhaust fan operation, 2) the case with natural wind but no exhaust fan operation and 3) the case with no natural wind but exhaust fan operation, are considered for the numerical analyses. The numerical results show that the natural wind causes a rapid spread of the fire along the tunnel resulting in rapid spread of the smoke and heat over the platform which affects the escape. The operation of the exhaust fan also results in the rapid spread of smoke and heat over the platform, but the time required for reaching the safe escaping height of the smoke layer with the exhaust fan operation is much longer than that without the exhaust fan operation. The numerical results also show that the required capacity of the exhaust fan becomes larger when the effect of the natural wind is included.

• Journal of Digital Contents Society
• /
• v.15 no.1
• /
• pp.53-60
• /
• 2014

Even if shots in frames may be variable in both movies and animations, close-up reveals the significance of the subject in the focus. Because directors and animators take the place the actor as character in animation while performance of actor plays an important role in the close-up in the movies, it is significant to understand the close-up in the animation. In the present study we investigate the dramatic effect of close-up in the animation narrative in animations for theaters. Among the various dramatic effects of the close-up, the natural flow of the narrative and the induction of immersing in emotion are focused. Descriptive close-up is analyzed as a dramatic effect of inducing the natural flow of the narrative. Psychological close-up is analyzed as the induction of immersing emotion by effective delivery of internal mental state of a character. By analyzing symbolic close-up as the induction of immersing in the play by producing a dramatic effect, we expect that the close-up contribute to the advance of animation narrative structure.

• Fire Science and Engineering
• /
• v.22 no.3
• /
• pp.201-207
• /
• 2008

In this study, three Dimensional CFD simulations were carried out to investigate the effective smoke extraction system in bi-directional road tunnel fires using FLUENT. Characteristics of transverse system with big size extraction port or with uniform extraction port, semi-transverse system and longitudinal system for smoke extraction system were analyzed. Air velocity, port size, and operating method were used with variable. Distributions of smoke spread, CO was analyzed. As a result, the transverse ventilation system with big size port was found to be more effective than the uniform ports for bi-directional road tunnel.

• Fire Science and Engineering
• /
• v.18 no.4
• /
• pp.103-109
• /
• 2004

The risk of underground space become an important issue of life safety thought the Taeku subway line Accident. It is essential to study of smoke control screen to minimize the damage of human life because of smoke passage and passenger evacuation routes are on the same vertical and dispersion movement. The Fire modeling result shows the effect of fire control screen can save the evacuation time about 2-2.5 times compare to existing the system However, The designs of fire control screen need to be complied with smoke control ventilation system to present optimum design and the position of installation.

• KIPS Transactions on Software and Data Engineering
• /
• v.5 no.11
• /
• pp.607-614
• /
• 2016

In this paper, we propose an intelligent fire learning and detection system using convolutional neural networks (CNN). Through the convolutional layer of the CNN, various features of flame and smoke images are automatically extracted, and these extracted features are learned to classify them into flame or smoke or no fire. In order to detect fire in the image, candidate fire regions are first extracted from the image and extracted candidate regions are passed through CNN. Experimental results on various image shows that our system has better performances over previous work.

• Information Systems Review
• /
• v.20 no.4
• /
• pp.43-57
• /
• 2018

We propose network effects upon the investment decision of cloud-based ERP. Using the survey data collected from 82 companies in 2015, we examine whether IT managers have an intention to adopt real options in order to manage the risk of cloud-based ERP investments and how the network effects influence upon the intention to adopt real options. Based on prior literature, we propose a research model with 4 hypotheses. We find partial support of the hypotheses from the empirical analysis: technological risks has a positive impact upon the adoption of real options such as defer, contract, and abandon. In contrast, we find no significant impact of security risks upon real options. We validate positive network effects upon the adoption of real options such as defer, contract, and abandon. This work empirically find that IT managers in Korean middle and small sized firms have an intention to adopt real options when the managers realize economic, technological, and relationship risks and when they expect network effects.

• Fire Science and Engineering
• /
• v.24 no.2
• /
• pp.133-138
• /
• 2010

Recently, evacuation safety of a resident of building become the major concern, because building has been higher and more complicated. Buildings in Korea should install the natural smoke venting or mechanical smoke exhaust equipment according to the building law. The smoke control is the most important to guarantee the evacuation safety. This study evaluate the influence to the height and temperature of smoke layer by enlarging smoke vent size and operating sprinkler system using CFAST (Version 6). Smoke venting size is larger, the effect to height and temperature of smoke layer is increased in below 5 MW fire. But, the correlation of these is decreased in above 10 MW fire. The case that opened smoke vent and sprinklered are applied, life safety criteria are satisfied regardless of fire size. After design the fire scenario according to the service and size of building. Install the smoke vent suitable for the fire size and verify that by experiment or simulation.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.13 no.6
• /
• pp.451-462
• /
• 2011

The smoke control system plays the most important role in securing evacuation environment when a fire occurs in road tunnels. Smoke control methods in road tunnels are classified into two categories which are longitudinal ventilation system and transverse ventilation system. In this study it is intended to review the characteristics of smoke behavior by performing numerical analysis for calculating the optimal smoke exhaust air volume with scaled-model and simulation when a fire occurs in tunnels in which transverse ventilation is applied, and for obtaining the basic data required for the design of smoke exhaust systems by deriving optimal smoke exhaust operational conditions for various conditions. As a result of this study, when the critical velocity in the tunnel is 1.75 m/s and 2.5 m/s, the optimal smoke exhaust air volume has to be more than $173m^3/s$, $236m^3/s$ for the distance of the smoke moving which can limit the distance to 250 m. In addition, in case of uniform exhaust the generated smoke is effectively taken away if the two exhaust holes near the fire region are opened at the same time.

• Fire Science and Engineering
• /
• v.20 no.3 s.63
• /
• pp.15-20
• /
• 2006

In this study the flow characteristics of smoke and heat on a bank type platform of the underground subway station are studied numerically by considering two different emergency operation modes. Effects of the natural flow through the tunnel and the stair ways are considered in the numerical simulations by using the measured velocities presented in Part I as the boundary condition. Distributions of heat, smoke, visible range and toxic gas on the platform are analysed for different smoke extraction flowrates corresponding to the two different emergency operation modes. The numerical results show that the extraction flowrate affects the smoke control performance significantly by improving the smoke removal performance as the extraction flowrate is increased.

• Fire Science and Engineering
• /
• v.24 no.3
• /
• pp.58-65
• /
• 2010

The fire accidents having recently occurred are getting more and more larger and causing lots of damage in terms of property loss and casualties increase, so there is in need of technical fire safety development like comprehensive prevention solution in order to effectively prevent. Especially, the needing of new paradigm for advanced fire safe technology is gathering strength in high-rise modern building construction. Therefore, we want to find out on this paper what is a correlation between heat release rate measurement and smoke release volume by three parts of oxygen consumption calorimeter in bench scale calorimeter (cone calorimeter/ISO 5660/Avg.500Kw), Medium scale calorimeter (Room corner tester, Single burning Item/ISO 9750, EN 13823/Avg.3MW), and large scale calorimeter (Industry calorimeter/Avg. 10MW). Thus, Smoke detective of new paradigm devised by making use of a correlation between heat release and smoke production is to help reduce loss property and casualties. Ultimately, based on this theory, a new concept of fire alarm and evacuation system will be developed and expected to apply to a skyscraper.