• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.1232-1233
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• 2006

To co-fire with commercial LTCC (Low Temperature Co-fired Ceramic) materials at $850^{\circ}C{\sim}880^{\circ}C$, different contents of $B_2O_3$ were added to the $Bi_2O_3-ZnO-Nb_2O_5$ (BZN) ceramics. According to the test results, the cubic phase of BZN was transformed into orthorhombic in all the test materials. $BiNbO_4$ phase was formed in test materials with $2{\sim}5wt%$ of $B_2O_3$ addition. The phase transformation of cubic BZN was controlled during the synthesis process with excess ZnO content. The Cubic and orthorhombic phases of BZN could coexist and be sintered densely at $850^{\circ}C/2hr$.

• Korean Institute of Interior Design Journal
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• no.37
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• pp.119-128
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• 2003

The goal of this study was to understand human behavior in reference to wayfinding during emergency situations. In an emergency situation, it is recommended that evacuees follow instructions about an available exit rather than finding their way on their own. Wayfinding studies suggest that landmarks affect entire route communication. Landmark analysis for this study Identified describability, e.g., name and simplicity of landmark features. A virtual reality (VR) simulation test was conducted to examine the effect of landmarks on wayfinding. The independent variables were landmarks, smoke. Results suggest that the describability of landmarks is a positive Influence to route communication. Findings from this study, however, Indicates that smoke condition did not significantly affect participants' wayfinding.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.57 no.4
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• pp.451-456
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• 2008

In this paper. we experimented and analyzed about evaporation and breaking process of filament by external flames and adsorption pattern in lamp bulb of evaporated filament particle according to the set-up directions of incandescent lamps. In the results of experiments, we could know that filament evaporation behavior of incandescent lamp that is established by down direction happened most vigorously and is difference in adsorption pattern of filament particle that is vaporized according to set-up directions. Also, glass bulbs were melted and filaments were evaporated by external flames, and finally molten marks were discriminated. We expect that become important data that this study finding reveals burnout cause of incandescent lamp in scene of a fire.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.100-101
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• 2019

For buildings where a large number of the evacuees who are restricted to evacuation behavior compared to normal people, evacuation safety zones should be secured against fire. In order to form a safe haven safety zone, we are going to predict the performance of the building and describe the plan to secure a safe haven zone accordingly.

• Spatial Information Research
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• v.18 no.5
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• pp.133-142
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• 2010

Many pedestrian or fire evacuation models have been studied last decades for modeling evacuation behaviors or analysing building structures under emergency situations. However, currently developed models do not consider the differences of visibility of pedestrians by obstacles such as furniture, wall, etc. The visibility of pedestrians is considered one of the important factors that affect the evacuation behavior, leading to making simulation results more realistic. In order to incorporate pedestrian's visibility into evacuation simulation, we should be able to give different walking speeds according to differences of visibility. We improved the existing floor field model based on cellular automata in order to implement the visibility. Using the space syntax theory, we showed how we split the indoor spaces depending on the different visibilities created by different levels of structural depths. Then, we improved the algorithm such that pedestrians have different speeds instead of simultaneous movement to other cells. Also, in order for developing a real time simulation system integrated w ith indoor sensors later, we present a process to build a 3D simulator using a spatial DBMS. The proposed algorithm is tested using a campus building.

• Journal of the Korea Concrete Institute
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• v.23 no.4
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• pp.431-440
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• 2011

Concrete structures exposed to fire produce changes in their internal structure, resulting in their service life reduction due to the deterioration of its strength and performance capacity. The deterioration level are dependent on the temperature, exposure time, concrete mix proportions, aggregate property, and material properties. This study was performed to evaluate the thermal behavior of ultra-high strength concrete for the parameters of water to cement ratio (compressive strength), fine to total aggregate ratio, and maximum coarse aggregate size. At room temperature and $500^{\circ}C$, tests of ultrasonic pulse velocity, resonance frequency, static modulus of elasticity, and compressive strength are performed using ${\varnothing}100{\times}200\;mm$ cylindrical concrete specimens. The results showed that the residual mechanical properties of ultra-high strength concrete heated to $500^{\circ}C$ is influenced by variation of a water to binder ratio, fine to total aggregate ratio, and maximum coarse aggregate size.

• Fire Science and Engineering
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• v.13 no.2
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• pp.26-32
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• 1999

We had investigated combustion pro야$\pi$ies of rice bran dusts. Decomposition of rice bran d dusts with temperature were investigated using DSC and the weight loss according to t temperature using TGA in order to find the thermal hazard of rice bran dusts, and the p properties of dust explosion in variation of their dust with the same particle size. Using H Hartman's dust explosion apparatus which estimate dust explosion by electric ignition after m making dust disperse by compressed air, dust explosion experiments have been conducted by v varying concen$\sigma$ation and size of rice br뻐 dust. According to the results for thermodynamic stability of rice bran dust, there are little change of initiation temperature of heat generation 때d heating value for used particle size. But i initiation temperature of heat generation decreased with high heating rate whereas d decomposition heat increased with particle size. Also, the explosion pressure was increased as t the ignition energy increased and average maximum explosion pressure was 13.5 kgv'cnt for 5 BJ/60 mesh and 1.5 뼈Ie미 dust concentration.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.5
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• pp.1157-1163
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• 2015

The purpose of this study is to reveal the effects of the number of users and their spatial distribution on the evacuation time in a road tunnel in the event of a fire. An agent-based evacuation model was implemented using Netlogo following the ODD protocol. The proposed model illustrates how the evacuation behavior of one can hinder others across different evacuation environments. Simulations show that evacuation time increases with the number of users when they are randomly located in a road tunnel.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.5
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• pp.2374-2381
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• 2012

The aims of this study are to verify the effecting factors in evacuation behavior under the corridor and stair width variation in evacuation experiments at university education facilities. To achieve these purposes, the present conditions of university education facilities were analyzed, and the evacuation experiment settings were established under different width of corridor and stairs. After the experiments, we asked the effecting variables to the evacuation behaviors under the variation of corridor, stair width and density of evacuee. The results of this study are as follows ; First, we found 3 main factors which affecting the evacuation behaviors ; environmental factors on building conditions, psychological factors on evacuee's characteristics and personal factors on evacuee's physical conditions. Second, the environmental factors such as the location of stairs for evacuation, recognition of wayfinding in fire condition are mainly affects the evacuation behaviors, but evacuee behaviors have little relations with fire extinguishing facilities and personality.

• Fire Science and Engineering
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• v.33 no.4
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• pp.70-76
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• 2019

This paper reports development of a low-power standalone heat detector using a Critical-Temperature Switch. The Critical-Temperature Switch, which is a thermally sensitive and passive component whose resistance decreases significantly at 70 ℃ due to a metal-insulator transition, provides reliable temperature measurements. This digital-like behavior of the Critical-Temperature Switch can detect fires without a microcontroller, meaning that it can minimize the power consumption of the standalone heat detector. The experimental results showed that the standalone heat detector using the Critical-Temperature Switch complied with the Notification of the National Emergency Management Agency. Compared to conventional standalone heat detectors, only 70% of the power was consumed monitoring the fires.