• Proceedings of the Korean Radioactive Waste Society Conference
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• 2017.05a
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• pp.173-174
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• 2017

• Proceedings of KOSOMES biannual meeting
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• 2017.04a
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• pp.247-247
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• 2017

• Journal of the Korean Society for Railway
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• v.19 no.6
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• pp.736-743
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• 2016

In accordance with the trend of higher speed and automation, the Train Control System is building on the technology of control methods using radio in the technology of exchanging information by wire, toward a wireless communication method that will be applied using LTE-R radio communication technology with $4^{th}$ generation LTE mobile communication a $2^{nd}$ generation GSM-R. Therefore, a standard specification suitable for the Korea Radio based Train Control System-2(below KRTCS-2) for the 350km/h class using wireless communication is created; a prototype based on the standard specification is installed on a high-speed train and is installed on a test section(Ik san-Jeong eup) on the Honam high speed line to ensure the reliability and safety of the standard specifications, which are verified through various performance tests. In the future, the standard specification that has been established as a national railway standard, and the standard specifications will be commercialized by applying the train control system to conventional and High speed railway lines.

• Journal of the Korean Applied Science and Technology
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• v.35 no.3
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• pp.816-825
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• 2018

Recently, it was emerged to need the necessity of LPG residues management due to the finding some substances such as rust. This study is performed to investigate the characteristics of LPG residues in the production and distribution stage of LPG. For the qualitative analysis of LPG residues, it was operated to be set up the analysis conditions(the flow rate, etc) of GC-MS and was performed to analyze the component of LPG residues. From the analysis result using GC-MS, it was shown that the component of LPG residues was turned out the plasticizer to be used in the rubber manufacturing process. The inorganic components of LPG residues were analyzed using ICP-OES. At the results of inorganic analysis, it was shown that the Si element was detected, which was presumably derived from defoamers used mainly in the LPG production. Also, the P and Zn element, which are estimated to be components of grease additives used for filling facilities, were also partially detected. No trace of rusting was detected in the LPG residues in the production and distribution stages analyzed in this study. But, as plasticizers and grease additives can affect to the LPG fuel system in vehicles, it will be necessary to use the proper quality of rubber and to expand the use of low boiling grease additives.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.11
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• pp.989-996
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• 2009

In this study, the effects of biofilter media type (three different activated carbons and anthracite), empty bed contact time (EBCT) and temperature on the removal of four aldehyde species (formaldehyde, acetaldehyde, glyoxal and methylglyoxal) in BAC filters were investigated. Experiments were conducted at three water temperature (5, 15 and $25^{\circ}C$) and four EBCTs (5, 10, 15, and 20 min). The experimental results indicated that the coal based BAC retained more bacterial biomass on the surface of the activated carbon than the other BACs, and increasing EBCT or increasing water temperature also increased the four aldehyde species removal in BAC filters. To achieve above 80% of removal efficiency for four aldehyde species in a BAC filter, above 15 min EBCT at $5^{\circ}C$ and 10 min EBCT at above $15^{\circ}C$ were required. The kinetic analysis indicated a first-order reaction rate for the biodegradation of four aldehyde species at various water temperatures. Data obtained from the BAC filters at various temperatures were also used to evaluate pseudo first-order rate constants for four aldehyde species. The half-lives evaluated for formaldehyde, acetaldehyde, glyoxal and methylglyoxal in the coal-based BAC ranging from 0.89 to 3.19 min, from 0.75 to 3.35 min, from 2.16 to 4.72 min and from 1.49 to 3.86 min, respectively, could be used to assist water utilities in designing and operating BAC filters.

• Journal of the Korean Applied Science and Technology
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• v.31 no.4
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• pp.562-571
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• 2014

In these days, many countries carry out many renewable energy policies to increase the renewable energy portion and to reduce the GHG(Green House Gas). In Korea, RPS(Renewable Portfolio Standards) focused on over 500MW power producers is conducting. And they are using the bio-fuel oil to meet their RPS quota. The oil is a mixture of animal and vegetable fat or fatty acid ester of them and should satisfy some specifications to use the power generation such as viscosity, pour point, acid number. Depends on the raw materials, quality characteristics of power bio-fuel oil are changed. By adding the power bio-fuel oil, pour point, density, sulfur content and viscosity are decreased and acid number, iodine number, oxygen content are increased. In this study, we test the quality characteristic of power bio-fuel oil and the property changes by the blending ratio of power bio-fuel oil & conventional fuel oil.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.11
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• pp.739-746
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• 2014

In this study, The effects of empty bed contact time (EBCT) and water temperature on the biodegradation of 8 UV filters in biological activated carbon (BAC) process were investigated. Experiments were conducted at two water temperatures (7 and $18^{\circ}C$) and three EBCTs (5, 10 and 15 min). Increasing EBCT and water temperature increased the biodegradation efficiency of UV filters in BAC column. EHMC and BZC were the highest biodegradation efficiency, but BP and 4-MBC were the lowest. The kinetic analysis suggested a first-order reaction model for biodegradation of 8 UV filters at various water temperatures and EBCTs. The first-order biodegradation rate constants ($k_{bio}$) of 8 UV filters ranging from $0.2730{\sim}0.6365min^{-1}$ at $7^{\circ}C$ to $0.4824{\sim}0.8743min^{-1}$ at $18^{\circ}C$. By increasing the water temperature from $7^{\circ}C$ to $18^{\circ}C$, the biodegradation rate constants ($k_{bio}$) were increased 1.5~2.1 times.

• Journal of Energy Engineering
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• v.24 no.4
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• pp.42-47
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• 2015

While the oxygen content of gasoline for automobiles in Korea is regulated to less than 2.3 weight %, European and World-Wide Fuel Charter (WWFC) regulate it to less than 2.7 weight %. The oxygen content of oxygen-containing materials increases the octane number of the fuel due to the secondary combustion in the internal combustion engine. It has been reported to be effective in reducing emissions, such as CO, HC, which is caused by incomplete combustion. Before 2000s in the United States and Europe, there has been many researches about vehicle application of the changes in oxygen content of gasoline. However, there are not many domestic researches which reflect the improvement of the fuel quality and automotive technology. In this study, fuels of three different oxygen contents were applied to GDI and MPI engines. As a result, the changes of fuel consumption and emission gas were very similar depends of the oxygen content changes. The PN in GDI engine was decreased as the oxygen content was increased.

• Journal of the Korean Applied Science and Technology
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• v.34 no.4
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• pp.1085-1093
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• 2017

Plasticizers are materials added to give softness and elasticity to plastics having rigid properties to give soft properties as products, and they are mainly added to high molecular materials to give flexibility to improve workability and to improve cold resistance, resistance to volatility and electrical properties. It is used for the purpose. Most plasticizers are inert liquids, similar in function to solvents but with high molecular weight and no volatility. In addition, when dissolved in petrochemical products, only the plasticizer is separated by the matrix effect with other compounds, and qualitative and quantitative analysis. In this study, qualitative and quantitative analysis of DOA and DOP, which are representative components of petrochemical products, were conducted using MD-GC/MS and developed an optimal plasticizer analysis method.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.25 no.12
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• pp.815-821
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• 2015

Maritime safety has been more critical recently due to the occurrence of shipboard accidents involving prime movers. As such, the propulsion shafting design and construction plays a vital role in the safe operation of the vessel other than focusing on being cost-efficient. Smaller vessels propulsion shafting system normally install high speed four-stroke diesel engine with reduction gear for propulsion efficiency. Due to higher cylinder combustion pressures, flexible couplings are employed to reduce the increased vibratory torque. In this paper, an actual vibration measurement and theoretical analysis was carried out on a propulsion shafting with V18.3L engine installed on small car-ferry and revealed higher torsional vibration. Hence, a rubber-block type flexible coupling was installed to attenuate the transmitted vibratory torque. Considering the flexible coupling application factor, reduction gear stability due to torque variation was analyzed in accordance with IACS(International Association of Classification Societies) M56 and the results are presented herein.