• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.05a
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• pp.225-226
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• 2016

Bottom ash generated in thermoelectric power plants could be used as substitutional fine aggregate such as pearlite of fireproof mortar due to its lightweight and porosity. Development of substitutional materials is necessary because pearlite has several problems such as production of carbon dioxide during manufacturing process and high price. This study is to confirm the possibility of air cooling process bottom ash for fireproof mortar as substitutional material of pearlite through basic experiment.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.28 no.4
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• pp.147-153
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• 2020

This study analyzed the outlook for aviation demand for the recovery of the aviation industry, focusing on airlines facing difficulties in management due to the Covid-19 crisis. Although the timing of the recovery in aviation demand is uncertain at the moment, this study is based on prior research related to Covid-19 and forecasts by aviation specialists, and analyzed by SWOT technique to a group of aviation experts to derive and suggest implications for the prospects of aviation demand. Looking at the implications based on the analysis results, first, customer trust to prevent infection should be considered a top priority for recovering aviation demand. Second, promote reasonable air price policy. Finally, it seeks to try various research and analysis techniques to predict long-term aviation demand to overcome Covid-19.

• Environmental and Resource Economics Review
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• v.3 no.1
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• pp.81-105
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• 1993

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.94-99
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• 2011

EMU(Electric Multiple Unit) of Seoul Metro are equipped with air conditioning and six line flow fans for air circulation. In summer, the air conditioning and line flow fans usually work at the same time. Recently, high oil price leads more people to use public transportation, which in turn makes them feel hotter inside the rolling stocks and complain about air conditioning state. In order to improve indoor air quality in summer, it is inevitable to increase the cooling capacity of air conditioners, which costs a lot of money. Thus, we need to raise cooling efficiency by rearranging existing devices effectively. In this study, we found a better way to improve refreshment inside the trains by changing the operation method of line flow fans and door opening systems. The results will help improve the cooling efficiency of EMU in summer. Also, more precise experiments and analyses of our data can lead to various methods to increase energy efficiency.

• International Journal of Naval Architecture and Ocean Engineering
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• v.6 no.2
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• pp.363-379
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• 2014

In an effort to cope with recent high oil price and global warming, developments of air lubricated ships have been pursued to reduce greenhouse gas emissions and to save fuel costs by reducing the frictional resistance. In this study, reduction in the frictional resistance by air lubrication with air layers generated on the lower surface of a flat plate was investigated experimentally in the large water tunnel of SSMB. The generated air layers were observed, and changes in the local frictional drag were measured at various flow rates of injected air. The results indicated that air lubrication with air layers might be useful in reducing the frictional resistance at specific conditions of air injection. Accordingly, resistance and self-propulsion tests for a 66K DWT bulk carrier were carried out in the towing tank of SSMB to estimate the expected net power savings.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2008.11a
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• pp.241-244
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• 2008

Recently, The high Air-Tightness and high heat insulation for building construction cause a ventilation air volume deficiency. Also, Worldwide high energy price is strongly urging to economize the air conditioning energy. Therefore Heat Recovery Ventilation is used for the satisfaction of ventilation air volume and building energy saving. Accordingly, this study dose the heat exchanger performance evaluation and economic efficiency evaluation of Heat Recovery Ventilation. And, we wish to make a basic study about HRV System application of HVAC System and Multi System Air-conditioning.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1799-1802
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• 2008

More than 7 million people use the Seoul metropolitan subway network daily. This number tends to increase due to the increase of oil price. Indoor air quality of electrical multiple unit (EMU) is strongly affected by outdoor air quality, however, indoor thermal comfort is subjected to heating, ventilating, and air conditioning (HVAC) system of EMU. In general, air temperature, humidity, air velocity, surface temperature, and illumination are key parameters affecting thermal comfort of passenger. It is known that the well-designed HVAC system should improve the thermal comfort of passengers and should increase the energy efficiency of HVAC system also. In this study, we analyzed the thermal comfort of advanced EMU developed by Korea Railroad Research Institute by using the computational fluid dynamics (CFD) in order to find the optimum HVAC system which can improve thermal comfort of passengers with a minimal energy use.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.863-868
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• 2008

In accordance with the guidelines on the balcony structure changes in December 2005, most of tenants were moving into apartment housing, expand the balcony, but some large deviation between the price construction costs set of cases, due to overuse and the cause of the dispute, and the housing law amended in 2007 due to price cap system is implemented, the cost of expansion the balcony overdose pointed out that there is set to boost the sale price has been raised. These issues in order to improve the government in January 2008, the "Note costs by the balcony expansion" suggested guidelines to protect the rights of tenants and wants to promote the settlement of the sale price cap system. This study calculated the "Note costs by the balcony expansion" window system based on double or single, high performance insulation window system of the quantitative performance analysis of each type window that purpose.

• Proceedings of the KIEE Conference
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• 2006.10d
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• pp.212-214
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• 2006

Air Management System is composed by Pump, Fan, Compressor and Blower In general their performances depend on the capability of the motor, power converter device and controller. Especially, it should be noticed upon designing Air Management System using for Fuel Cell System, that Pump, Fan, Compressor and Blower satisfy the condition of the high performance, high efficiency, high density and reasonable price considering the safety and Economic Efficiency. In order for this, it should be studied that which kind of Motor is the most suited for Air Management System for Fuel Cell, such as Induction Motor, Brushless DC Motor, and Switched Reluctance Motor which is widely using in industry. This paper presents the designing and manufacturing of Outer Rotor Type BLDC Motor and Driver for Air Blower of Air Management System. Experimental results from a laboratory prototype arc presented to validate the feasibility of the proposed Air Blower Motor and Driver.

• Journal of the Korean Society of Combustion
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• v.20 no.2
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• pp.40-45
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• 2015

This study is aimed to study combustion characteristics of low $NO_X$ burner using petroleum cokes as fuel. The petroleum coke, which is produced through the oil refining process, is an attractive fuel in terms of its high heating value and relatively low price. But petroleum coke is a challenging fuel because of its low volatile content, high sulfur and nitrogen content, which give rise to undesirable emission characteristics and low ignitability. The petroleum cokes burner is operated at fuel rich condition, and overfire air are supplied to achieve fuel lean condition. The low $NO_X$ burner is designed to control fuel and air mixing to achieve air staged combustion, in addition secondary and tertiary air are supplied through swirler. Air distribution ratio of triple staged air are optimized experimentally. The result showed that $NO_X$ concentration is lowest when overfire air is used, and the burner function at a fuel rich condition.