• Tunnel and Underground Space
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• v.22 no.5
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• pp.365-372
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• 2012

This paper aims to evaluate the effects that presence, installation number and capacity of ventilation vent and presence of multiple fire sources have on the behaviour of smoke temperature induced by vehicle fire in road tunnel. Six types of scenarios were assumed and FDS was ran to simulate them. As the number of ventilation vents increases, the smoke temperature are calculated to be reduced, but it is shown that effects exerted by two ventilation vents are almost similar to ones by three ventilation vents. Capacity of ventilation vent has a greater impact on the reduction of smoke temperature than installation number of ventilation vents. Smoke temperatures computed for all scenarios except for scenario No. 1 (without ventilation vent) and scenario No. 6 (with multiple fire sources) above fire source are analyzed to be under $400^{\circ}C$ and it means that the radiation of smoke layer above fire source doesn't induce the ignition of materials around fire source.

• Fire Science and Engineering
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• v.25 no.3
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• pp.85-90
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• 2011

This study of the vestibule of pressurizing smoke control system installed in domestic high-rise buildings for evacuation in case of fire, when the door is open to forming characteristics of the air flow was analyzed using fire dynamics simulator and analyzed of variance. Vestibule which is compartment of the design condition, air flow in the exhaust damper was formed severe turbulence confirming preceding research. The door position is in the range of formed vortex, unsteady flow of air occurs at the point that the door could be confirmed. According to the NFSC 501A, door to symmetrically separate the average of 10 points or more as measured from the average of wind speed to do is based. Under these conditions, it is difficult to measure the characteristics of the upper air flow of upper points. so measuring points are subdivided by more than 64 points method presented in TAB because severe deviation of wind speed.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.30 no.6
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• pp.78-83
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• 2002

A modified patched grid scheme has been developed and employed for and axi-symmetric unsteady Euler solver based on Roe's FDS to analyze the unsteady flow fields induced by a train and a tunnel. On this paper, the innovative zonal method, named hybrid dimensional approach, was proposed and applied to the train-tunnel interaction problems. The basic idea of this method is to maximize the efficiency of numerical calculations by minimal assumption of spatial dimensions. The hybrid dimensional approach, embedded in the present modified patched grid method, yielded high numerical accuracy as much as the fully axe-symmetric method. The hybrid dimensional approach is expected to reduce the huge computation time of the train-tunnel interaction problems especially in the cases of solving a long tunnel.

• Bulletin of the Korean Chemical Society
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• v.19 no.11
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• pp.1222-1227
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• 1998

The crystal structure of a benzene sorption complex of fully dehydrated Cd2+-exchanged zeolite X, Cd46Si100Al92O384·43C6H6 (a=24.880(6) Å), has been determined by single-crystal X-ray diffraction techniques in the cubic space group Fd3 at 21 ℃. The crystal was prepared by ion exchange in a flowing stream of 0.05 M aqueous Cd(NO3)2 for 3 d, followed by dehydration at 400 ℃ and 2 x 10-6 Torr for 2 d, followed by exposure to about 92 Torr of benzene vapor at 22 ℃. The structure was determined in this atmosphere and refined to the final error indices R1=0.054 and Rw=0.066 with 561 reflections for which I > 3σ(I). In this structure, Cd2+ ions are found at four crystallographic sites: eleven Cd2+ ions are at site 1, at the centers of the double six-oxygen rings; six Cd2+ ions lie at site I', in the sodalite cavity opposite to the double six-oxygen rings; and the remaining 29 Cd2+ ions are found at two nonequivalent threefold axes of unit cell, sites Ⅱ' (in the sodalite cavity ) and site Ⅱ (in the supercage) with occupancies of 2 and 27 ions, respectively. Each of these Cd2+ ions coordinates to three framework oxylkens, either at 2.173(13) or 2.224(10) Å, respectively, and extends 0.37 Å into the sodalite unit or 0.60 Å into the supercage from the plane of the three oxygens to which it is bound. The benzene molecules are found at two distinct sites within the supercages. Twenty-seven benzenes lie on threefold axes in the large cavities where they interact facially with the latter 27 site-Ⅱ Cd2+ ions (Cd2+-benzene center=2.72 Å; occupancy=27 molecules/32 sites). The remaining sixteen benzene molecules are found in 12ring planes; occupancy=16 molecules/16 sites. Each hydrogen of these sixteen benzenes is ca. 2.8/3.0 Å from three 12-ring oxygens where each is stabilized by multiple weak electrostatic and van der Waals interactions with framework oxygens.

• Journal of the Korean Institute of Gas
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• v.7 no.3 s.20
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• pp.44-50
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• 2003

The axisymmetric methane-air counterflow flame was simulated to investigate changes in the flame structure due to the fuel concentration and to evaluate the numerical method. The global strain rates $a_g=20,\;60,\;90\;s^{-1}$ and the mole fractions of methane $x_m=20,\;50,\;80\%$ in the fuel stream were taken to be numerical parameters. The axisymmetric simulation was conducted by using the Fire Dynamics Simulator (FDS) which employed a mixture fraction combustion model, and the results were compared with those of OPPDIF, which is an one-dimensional flamelet code and includes detail chemical reactions. In all the cases tested, there was good agreement in the temperature and axial velocity profiles between the axisymmetric and one-dimensional simulations. It was shown that the flame thickness and peak flame temperature increase and the flame radius decreases as the fuel concentration increases.

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.4
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• pp.440-448
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• 2007

Although the anthracite power plant is an important source of greenhouse gas, research on this type of power plant has not been conducted much. The present study investigated the entire anthracite power plants in Korea and analyzed the emitted gas in connection with GC/FD and a methanizer in order to develop $CO_2$ emission factors. The study also sampled the anthracite to analyze the amount of carbon and hydrogen using an element analyzer, and to measure the calorie using an automatic calorie analyzer. The emission factors computed through the fuel analysis was 30.45 kg/GJ and that computed through the $CO_2$ gas analysis was 26.48 kg/GJ. The former is approximately about 15% higher than the latter. When compared the carbon content factors of anthracite with that of bituminous coal, the value of anthracite was 24% higher Compared with IPCC values, the emission factors by the fuel was 14% higher, and that by the emitted $CO_2$ gas was about 1.2% lower. More research is needed on our own emission factors of various energy-consuming facilities in order to stand on a higher position in international negotiations regarding the treaties on climate changes.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.12
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• pp.6208-6214
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• 2012

The most essential but missing components to understand and use toxic substances from marine microalgae are developing the fast, easy and economical determining technology for detecting it. In this paper we produced the antibodies against saxitoxin (STX). Mariculture keyhole limpet hemocyanin (mcKLH) and ovalbumin (OVA) were used as carrier proteins. mcKLH-STX conjugates were injected into the peritonial cavity of BALB/c mouse for immunization. After bleeding from mouse, anti-STX antiserum was isolated. Indirect enzyme-linked immunosorbent assays (ELISA) was performed to determine antiserum titer using the microtiter plate coated with free STX and OVA-STX. A goat anti-mouse IgG-phosphatase conjugate was used as secondary antibody to enable chromogenic reaction. Reactions of anti-STX antiserum were very specific on the OVA-STX and free STX. Sensitivity of anti-STX antiserum on STX was very high and STX detection limit was to be 64.9 ng/kg for indirect ELISA.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.12
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• pp.6013-6021
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• 2012

Although there are many patients who suffer from cold hypersensitivity and have a difficult time in living daily lives due to feeling cold at room temperature, it is about true that an accurate diagnostic method and an effective remedy for a cold hypersensitivity have not been developed yet. Therefore, in order to develop traditional medicine equipment for cold hypersensitivity, we have designed new oxygen chamber system which can diagnose cold hypersensitivity with multiple bionic sensors and supply a patient optimum amount of oxygen adaptively to the extent of their illness. In particular, diverging from conventional diagnosis based on the experience of doctor and subjective statements of patient, we introduced accurate method for diagnosis in comparing between output of multiple sensors and threshold derived from clinical trials. After all, the proposed oxygen chamber system will contribute to achieving scientific evidence and manufacturing of korean traditional medicine.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.6
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• pp.2720-2728
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• 2012

Recently flexible mobile terminals which can freely change the shape of their device are coming out with the development of the flexible display, high capacity memory and system integration technology. The display and the antenna configuration of the future terminals will be altered according to the QoS (quality of service) and the communication environment of users. In particular, we present the new emergence of a multimedia language for human and system to communicate over subjective concepts, intention of users. The intension of users is expressed by changing the shape of their mobile terminal. In addition, antenna configuration is also related to shape of terminal and QoS of users. Therefore, we set up a specific usage scenarios for future mobile terminals and propose an adaptive MIMO (multiple-input multiple-output) schemes that can maximize channel capacity and fit to QoS of users simultaneously.

• Journal of the Korean Society of Safety
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• v.31 no.2
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• pp.1-9
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• 2016

The standard procedure of fire modeling was reviewed to minimize the user dependence, based on the NUREG-1934 and 1824 reports. The hazard analysis of lubricating oil fires in the air compressor room of domestic nuclear power plant (NPP) was also performed using a representative fire model, FDS (Fire Dynamics Simulator). The area ($A_f$) and location of fire source were considered as major parameters for the realistic fire scenarios. As a result, the maximum probability to exceed the thermal damage criteria of IEEE-383 unqualified electrical cables was predicted as approximately 70% with $A_f=1m^2$. It was also found that for qualified electrical cables, the maximum probabilities of exceeding the criteria were 2% and 90% with $A_f=2$ and $4m^2$, respectively. It was concluded that all electrical cables should be replaced with IEEE-383 qualified cables and the dike to restrict as $A_f{\leq}2m^2$ should be installed at the same time, in order to assure the thermal stability of electrical cables for lubricating oil fires in the air compressor room of domestic NPP.