• The Journal of Engineering Research
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• v.3 no.1
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• pp.199-205
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• 1998

Cullet Quality Control in auto glass bottle factory is the most important in recent days because of the increasing cost of materials in glass bottle. Since the composition of plate glass cullet is similar, the cullet quality using plate cullet in glass bottle factory is easily controlled. In addition to this, the price of plate glass cullet is so low that the cost reduction can be achieved. If the ratio of plate glass cullet and gush is over 25%, the liquidity of glass water become worse, which is caused by different compositions and viscosity of the components. As a results, Furnace bottom temperature becomes low and glass water becomes inhomogeneous. Thus production efficiency of glass bottle becomes low because of increasing devitrification in Dead Corner part in glass melting furnace. Three experimental methods – (1) increasing melting temperature, (2) using Booster, (3) using bubbler – were performed to increase the furnace bottom temperature and glass water homogeneity. The amounts of plate glass cullet was able to increase up to 90%, 70% and 60% without any devitrification using booster, bubbler and the method of glass melting temperature increase from $1480^{\circ}C$ to $1560^{\circ}C$ respectively. It is not possible to increase the glass melting temperature without the reduction of furnace operation time and the increase of fuel cost. The booster process has disadvantage of much electric energy consumption. Since the bubbler process uses physical convection of melting glass based on compression air, the homogeneity of molten glass is not so good as that of booster process but it can reduce the cost of glass bottle.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.12
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• pp.45-56
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• 2002

A pneumatic servo system requiring a fine gap control in a photo-electric sensor which is used for a LCD array detection device is introduced. The gap controlled by the pneumatic servo system remains within around 50~80 ${\mu}{\textrm}{m}$, and the system possesses an effect to eliminate undesirable particles on the LCD plate by blowing air out. The air flow rate is initially controlled by a servo valve and expanded by a booster valve, thus the controlled air pressure contributes to maintaining an appropriate gap between the LCD plate and photo-electric sensor An air floating plate of two degrees of freedom is designed and fabricated, and a fine tilting motion control is also implemented by assigning different gap commands. The pressure control and direct gap control are proposed, and each performance is verified experimentally.

• Transactions of the Korean hydrogen and new energy society
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• v.28 no.6
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• pp.675-682
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• 2017

New government, the market for stationary fuel cell systems in domestic is expected to expand in line with the policy for expanding new and renewable energy. In order to promote and expand the domestic market for stationary fuel cell systems, it is required to do research and develop for cost reduction and efficiency improvement technologies through the localization of BOP. In this study, the safety performance including the power consumption, flow rate, noise and air-tightness of the domestic fuel booster blower and the foreign fuel booster blower was evaluated and the performance improvement of the domestic blower was confirmed. As a result of the power consumption measurement and the flow rate according to the back pressure of the A company 2nd prototype and B company, the values were 73 W, 27 LPM, and 55 W, 25 LPM. These results are attributed to the improvement of performance through design changes such as CAM angle and diaphragm material.

• Proceedings of the KIEE Conference
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• 1998.07b
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• pp.825-827
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• 1998

Air pollution is one of the most important global issues of the environmental concerns. Some advanced foreign countries have developed the air pollution control technology. KEPCO has been researching on the air pollution control technology and developed the FGD(Flue Gas Desulfurization) system for 200MW thermal power plant. In this paper, we describe the major control loops implemented to the domestic FGD system. The major control loops are to be classified into booster fan control, absorber PH control and limestone density control. The control loops were applied to the actual desulfurization processes and proved to their performance.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.3
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• pp.72-78
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• 2003

In this paper, the feasibility study and the parametric design of hybrid motor with HTPB/LOX were conducted for micro air launch system. Design results were compared with 1st stage of Pegasus XL for verification of hybrid motor. Results showed that hybrid motor replace solid booster if Isp of hybrid motor reaches 330sec. In addition, mission analysis was established for micro air launch system, and parametric design was conducted with design variables: number of port, initial oxidizer flux, and chamber pressure. And the region of Isp was identified by parametric study which satisfied design constraints and mission analysis.

• The KSFM Journal of Fluid Machinery
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• v.12 no.5
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• pp.19-24
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• 2009

This paper is performed to find out the stability of water-hammer in pipe line and pump station that is happened when additional water needs demanded. At first, the water supply construction project is planned to supply $6,000\;m^3/day$ through 17.9 km pipe line. But additional demand ($1,200\;m^3/day$) happened from Cheong-ra water reservoir. In this situation, air-chamber($4\;m^3$) and vacuum breaker valve(${\varphi}100\;mm$) are needed to prevent water-hammer. When the additional water is supplied, the existing facilities (air-chamber, vacuum breaker valve) are sufficient to alleviate shock not changing capacity alteration, judging from the airspace change and rise. Therefore, there is no problem for water-hammer by installing air-chamber($4\;m^3$) and vacuum breaker valve(${\varphi}100\;mm$) at the top of Yeo-ju hill.

• Tunnel and Underground Space
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• v.2 no.1
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• pp.116-122
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• 1992

A comprehensive, nonsteady state, computer simulation program for the environmental conditions in advancing tunnels (the HEADSIM simulation program) is constructed and successfully validated with heat balance amongst all heat sources, and with mass conservation amongst various airflows including the leakage air from ducts, under timedependent variations of inlet air conditions. which include sudden, diurnal and seasonal changes. Heat conduction in the wall strata and face strata is simulated with most complicated boundary conditions using the finite difference method, and the climatic conditions in roadway sections which contain air ducts, booster fan, spray cooler, compressed air pipes, cold water pipes, return water pipes, machinery and broken rock are simulated taking into account the variations of face operation and the heat storage mechanism in the strata. The limitations of simulation time steps and roadway section lengths are defined according to the stability criteria satisfying the principles of thermodynamics. Variations of heat transfer coefficients, which are newly set, and those of wetness factors are taken into account according to the variations of other parameters and the stepwise advance of the face. Newly-derived formulae are used for computing the air duct leakage and the pressure inside of the duct. A new concept of an 'imaginary duct' is introduced to simulate the climatic conditions in tunnels during holiday periods, which directly affect conditions on subsequent working days under the consideration of natural convection. A subsidiary program (the WALLSIM simulation program) is made to compute the dimensionless tunnel surface temperatures and to compare the results with those from analytical approaches, and to demonstrate the stability, convergence and accuracy of the strata heat conduction simulation, adopting the finite difference method. The WALLSIM also has wide applications, including those for the computation of age coefficients.

• Journal of the Korean Society of Safety
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• v.26 no.1
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• pp.1-7
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• 2011

When the pumps stopped in the operation by the power failure, the hydraulic transients take place in the sudden change of a velocity of pipe line. Each and every water hammer problem shows the critical stage to be greatly affected the facts of safety and reliability in case of power failure. The field tests of the water hammer executed at Cheong-Yang booster pump station having an air chamber. The effects were studied by both the practical experiments and the CFD(Computational Fluid Dynamics : Surge 2008). The result states that the system with water hammering protection equipment was much safer when power failure happens. The following data by a computational fluid dynamic analysis are to be shown below, securing the system stability and integrity. (1) With water hammering protection equipment. (1) Change of pressure : Up to $15.5\;kg/cm^2$ in contrary to estimating $16.88\;kg/cm^2$. (2) Change rate of water level : 52~33% in contrary to estimating 55~27%. (3) Note that the operational pressure of pump runs approx. 145 m, lowering 155 m of the regularity head of pump. (4) Note that the cycle of water hammering delays from 80 second to 100 second, together with easing the function of air value at the pneumatic lines. (2) Change of pressure without water hammering protection equipment : Approximate $22.86\;kg/cm^2$. The comprehensive result says that the computational fluid dynamics analysis would match well with the practical field-test. It was able to predict Max. or Min. water hammering time in a piping system. This study aims effectively to alleviate water hammering in a pipe line to be installed with air chamber at the pumping station and results in making the stability of pump system in the end.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.4
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• pp.228-232
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• 2015

The water supply galvanized steel pipes of apartment buildings in Bucheon city constructed with building permission before 1994 have many problems such as leaks, the water containing rust, and low water pressure due to corrosion. Therefore, this study aims to find a way to renew the water supply pipes under investigation through a survey. As a result, when replacing the galvanized steel pipe with the corrosion-resistant pipe, the water supply system should also be changed from the gravity tank system to the booster pump system and the hygienic water storage tank. It is necessary to redraft the long-term repair plan including the replacement of the water supply system. Also, it is necessary to save the allowance reserve according to the modified long-term repair plan.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.05a
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• pp.381-384
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• 2009

The Air-breathing engine like Sea-Star I is a second propulsive force generator to fly to the target after the booster generating initial propulsive force is separated. The performance of Sea-Star I engine should be verified because the cruise missile controls direction and altitude during flight, so ground engine test is executed before flight test. This these presents evaluation method of ground engine test to verify performance of Sea-Star I's engine.