• Fire Science and Engineering
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• v.27 no.2
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• pp.6-10
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• 2013

This study aims to construct the performance data for smoke-control zone and realize the safety of injection and pressurization room which is composed of supply air pressure zone, vestibule, smoke-control zone and stairwell. To obtain this, smoke-control system and the device of the opening-closing force of fire door are manufactured. This subject is the analysis of the closing force, angular velocity and fire door size in the case of fixed volume flow rate. Based on the results, closing force increased as fire door size and closing angular velocity increases. Also, it is remark that there exists a critical angular velocity, which maintains constant maximum closing force even though the angular velocity increases more.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.1
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• pp.60.2-60.2
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• 2015

Since its detection in 1980, the $8-{\mu}m$ north-polar brightening of $CH_4$ on Juptier has not moved from $180^{\circ}$ (SysIII) longitude. The $8-{\mu}m$ $CH_4$ brightening is mostly thermal and very similar to that of $13-{\mu}m$ $C_2H_2$ emissions, but the morphology of these hydrocarbon north-polar brightenings are very different from that of the $3-{\mu}m$ $H_3{^+}$ auroral oval suggesting a significantly different excitation process yet unknown heating mechanism. Recently, Kim et al. (submitted to Icarus, 2015) found that that the center of the $3-{\mu}m$ $CH_4$ northern bright spot is located at ${\sim}200^{\circ}$ (SysIII) longitude, which is ${\sim}20^{\circ}$ west from the center of the $8-{\mu}m$ north-polar bright spot, and it does not coincide with the $3-{\mu}m$ $H_3{^+}$ bright spot. They found significantly high temperatures (500 ~ 850K) from $CH_4$ rotational lines on the $3-{\mu}m$ bright spot above the $1-{\mu}bar$ pressure level, while we find cooler temperatures (<350K) over the the $8-{\mu}m$ spot. They also found that the upper states of the $3-{\mu}m$ $CH_4$ bands are mostly populated by non-thermal excitations, such as auroral particle precipitations and/or Joule heatings in contrast to the $8-{\mu}m$ thermal emission. This finding indicates that the $10-{\mu}m$ hydrocarbon brightening is confined to low altitudes below the $1-{\mu}bar$ level eliminating the long-suggested possibility of direct auroral bombardments while opening a new possibility of dynamical origin for the $10-{\mu}m$ brightening.

• Journal of the Society of Naval Architects of Korea
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• v.49 no.2
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• pp.203-211
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• 2012

The main object of this experiment is to estimate the hydrodynamic forces acting on a submerged streamlined body placed in a one-end-opened cylindrical tube moving with certain translational velocity. The best experimental design for this object is mimicking real situation, however sizes of model body and cylinder tube are just the same as those of real, for avoiding scale effects, mimicking real situation is not realizable. Hence, in this experiment, target body and cylindrical tube were designed to be towed with varying body position relative to cylindrical tube. For measuring hydrodynamic forces and flow velocity in the cylindrical tube, six one-component load cells and several one-hole Pitot tubes were used. Several conditions were checked with various end-plates those had different opening areas. Experiment results show that forces and flow velocity had different tendency with those expected, and the presence of a end-plate slows down the flow velocity in the cylindrical tube and affects pressure field in the tube to push the model submerged body forward of the tube. This tendency grows with decreasing opened area.

• Journal of Aerospace System Engineering
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• v.14 no.5
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• pp.91-99
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• 2020

A liquid rocket engine goes through many tests to prove its performance before liftoff. It means the tests for setting ignition and start-up conditions or a test on design condition, which verifies the design performance. However, the development process requires verification of performance under off-design conditions through tests involving different operating conditions, which affects the duration of engine development. The off-design performance test is performed by altering the conditions of the propellant supplied to the engine in conjunction with the engine performance test that varies the opening of the control valves in the engine. This paper is based on the results of the engine tests performed at the KSLV-II engine test facilities in the Naro Space Center and describes the operations of the test facility for off-design condition test that changes the inlet conditions of the turbo-pump due to changes in the pressure and temperature of the propellant supplied to the test engines.

• International Commerce and Information Review
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• v.1 no.2
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• pp.1-24
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• 1999

In this study, I have suggested a basic theories in introducing and applying EC indispensible for a positive development of international logistics' competitiveness by the Chonbuk firms, and I assure that the Chonbuk firms can get a full effect in strengthening international competitiveness in worldwide trade war by effectively utilizing the application method suggested in this study as well as by erecting its basic direction. Our market faced an accelerating pressure against a full-scale market opening with the WTO system, and our Chonbuk firms will face a danger that all the markets, domestic and international will be occupied by the foreign enterprises, for we can not win the competition with the foreign enterprises, provided that we do not prepare for the rationalization and effectiveness of management. It will be very significant for our Chonbuk firms to introduce and utilize EC as a method for innovation and rationalization of management as well as a method for strengthening international competitiveness. This study will serve the study of this field, for the purpose of this study is on analyzing its propriety in introducing and utilizing EC. It will guarantee the importance that this study helps the Chonbuk firms to upgrade understanding on introduction and utilization of EC for strengthening their logistics competitiveness, and this study serves to improve international competitiveness in an era of information and globalization.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.1
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• pp.89-95
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• 2015

A surge phenomenon cause noise and pulsations in a turbo compressor, which is an unstable operating regime. Because surge protection ensures a safe compressor operation, it is important to understand the physics of the surge phenomenon. In this study, the surge characteristics of a 250-hp class turbo-compressor were evaluated experimentally. The experimental parameters were the rotational speed, opening angles of the inlet guide vane and exit valve, and inlet pipe diameter and flow rates of the inlet gases. The results showed that the compressor surge was very sensitive to the gas flow rates, exit pressure, rotational speed, and bypass flow rates.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.3
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• pp.237-244
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• 2011

An experimental study was carried out to investigate the effect of the inclination angle on the nucleate pool boiling of saturated water at atmospheric pressure. We considered an annulus with a gap of 5 mm and a bottom opening. The inner tube of the annulus was heated, and the outer diameter and the length of the tube were 25.4 mm and 500 mm, respectively. The inclination angle was varied from horizontal to vertical. The results were compared to those for an annulus with a larger gap and a single tube. In the small-gap annulus, the effect of the inclination angle on the heat transfer was not significant. However, an early onset of the critical heat flux was observed at 80 kW/$m^2$ when the annulus was horizontal. Liquid agitation and bubble coalescence were considered to be the major heat-transfer mechanisms.

• Journal of Navigation and Port Research
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• v.28 no.6
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• pp.491-496
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• 2004

The paper describes measurement techniques for an acoustic transfer characteristic of ship's bridge stimulated by a whistle sound The response sounds, according to the opening-shutting conditions of bridge doors for Training Ship ‘SAENURI’, are measured by B＆K 2260D equipment, and then the frequency responses are extracted by B＆K 7830 software. To evaluate the measured transfer characteristic, the 128th order FIR (Finite Impulse Response) filters, containing the different frequency characteristics, are constructed based on the frequency sampling-based design method Using evaluation indexes with six scales, psychological assessments by five subjects are carried out with test sounds which are obtained from convolving the source signal with FIR filters. As results of tests, the test sounds gives $A_S$ 3.3∼4.7 which means the psychological sense of ‘it is almost similar sound as original ones in a real world’, and thus it is clearly seen that the proposed method can be used for the measurement of an acoustic transfer characteristic of ship’s bridge.

• The Journal of the Korea Contents Association
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• v.13 no.10
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• pp.234-255
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• 2013

Korean Academy of Film Arts (KAFA) is the film school run by Korean Film Council (KOFIC). KAFA was established in 1984, benchmarking American Film Institute (AFA) and in order to foster manpower for Korean Movie under the US's pressure of domestic movie market opening in Korea. The Korean Movie market was open to the world by 1987 and suffered from the low Korean-produced movie market share of around 20% in the domestic market from 1987 to 1998. During the last 30 years, KAFA plays the key role in the Korean movie making industry. Of 520 of number of their alumni, the number of directors is 101, 33 of cinematographers, 18 of producers and 21 of professors in universities' film departments. Korean Directors, Bong Joon-ho of (2013) and topped over 10 million domestic admissions to become the most-watched Korean films of all time. Now, with KAFA's relocation to Busan following with KOFIC, their new roles are promotion of the film industry in Busan, recruiting and educating new talented Korean and foreign student filmmakers, becoming an international film school.

• Journal of the Korean Institute of Gas
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• v.21 no.5
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• pp.45-55
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• 2017

Release and fire/explosion tests of flammable gas are extremely dangerous. Furthermore, it is difficult to select the site where the experiment can be performed. In these reasons, gas flow analysis(CFD) has been used as much as possible. However, with the opening of the Energy Safety Empirical Research Center in Yeongwol-gun, Gangwon-do in October 2016, it was possible to conduct releases and detection tests of small scale combustible gas as well as large scale / high pressure / ultra low temperature experiments. In this study, LPG leaked after the calibration and placement of the sensor, the sensor detected LPG and the data were visualized as a contour map. And the differences between the actual release(28s, max 3.7[m]) and the analysis were analyzed compared to the FLACS analyzed under the same conditions.