• Journal of the Korean Applied Science and Technology
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• v.34 no.4
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• pp.1046-1057
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• 2017

Country-specific emission factors should be developed and used instead of IPCC defaults to improve national GHG inventories to Tier 2 and above. Since the country-specific emission factors depend on the type of energy source, energy process, and time trend, identifying the value of each energy source is an important part of building an accurate inventory. In this study, calorific value and carbon emission factor for petroleum energy sources on the basis of calorific value conversion standard for energy source, which are notified in Korea, are collected by 2013 and 2016, and calorific value, carbon content and carbon emission factor And a comparative analysis was conducted. In addition, net calorific values and carbon emission factors calculated for each petroleum based energy source are compared with those shown in 2006 IPCC Guideline.

• Journal of Power System Engineering
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• v.18 no.6
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• pp.106-112
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• 2014

The diesel engine, which has high compression ratio than other heat engines, has been using as the main power source of marine transport. Especially, since marine diesel engines offer better specific fuel consumption (SFC), it is environment-friendly compared to those used in other industries. However, attentio should be focused on emissions such as nitrous oxide ($N_2O$) which is generated from combustion of low-grade fuels. Because $N_2O$ in the atmosphere is very stable, the global warming potential (GWP) of $N_2O$ is 310 times as large as that of $CO_2$, and it becomes a source of secondary contamination after photo-degradation in the stratosphere. It has been hitherto noted on the $N_2O$ exhaust characteristics from stationary power plants and land transportations, but reports on $N_2O$ emission from the marine diesel engine are very limited. In this experimental study, a author investigated $N_2O$ emission characteristics by using changed diesel fuel components of nitrogen and sulfur concentration, assessed on the factors which affect $N_2O$ generation in combustion. The experimental results showed that $N_2O$ emission exhibited increasement with increasing of sulfur concentration in fuel. However, all kinds of nitrogen component additives used in experiment could not change $N_2O$ emission.

• Journal of Climate Change Research
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• v.8 no.2
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• pp.177-186
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• 2017

In this research, we have developed standardized procedures for preparing of emission inventories on military sector. The procedures are as follows; 1) Identify all relevant emission sources list of military sector in Republic of Korea. 2) Select methods to estimate GHGs emissions by source categories such as heating boilers, tactical vehicles, military vessels and military aviation from US EPA, IPCC, EEA/EMEP, and ROK Ministry of Environment. 3) Identify and select data sources for activities and parameters from Korea annual oil statistics and Korea Procurement system. 4) Compare with each GHGs emission used by each activities. The conclusive results utilized by emission source categories and associated factors are described as follows; In 2013, GHGs was estimated 2,656 kilotons $CO_2-eq$ emitted by military sector. The diesel combustion contributed from a minimum of 43.8% to a maximum of 50.2% and JP-8 contributed from a minimum of 43.7% to a maximum of 52.8% to the 2001~2015 GHGs emission trend. In the result of comparing GHGs emissions with Korea Annual Oil Statistics (Tier 1) and supplied fuel through the Korea Procurement System (Tier 2) in 2015, the total GHGs emission was 2,867 kilotons $CO_2-eq$ estimated by Tier 2 is similar to the emission estimated by Tier 1. However, this reveals that the GHGs emission separated by local areas were a lot of different from Tier 1 and 2. The cause of difference between Tier 1 and Tier 2 was that Korea annual oil statistics utilized data from a fuel supplier. The data does not reflect the reality of the location of end user.

• Transactions on Electrical and Electronic Materials
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• v.14 no.1
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• pp.24-27
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• 2013

In this paper, we investigated the effect of luminescence properties of various concentrations of magnesium-doped ZnS:Mn phosphor excited by plasma luminescence device. The PL intensity was evaluated in the range of 300~500 nm excitation wavelengths. We found the highest PL intensity of the phosphors excited by 365 nm and 450 nm was observed at Mg concentrations of 1.4 wt% and 0.8 wt%, respectively. In addition, an emission peak was distinguished at 580 nm wavelength. With increasing Mg dopant level, enhanced PL intensity was observed, which is possibly applicable to color converting materials by blue emission for white light sources. Finally, we evaluated the luminance properties of color converting ZnS:Mn,Mg phosphors with plasma blue light source. the white luminance of plasma light source with CIE(0.36,0.26) was established by color converting phosphors of ZnS:Mn with 0.8 wt% Mg.

• Smart Structures and Systems
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• v.32 no.4
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• pp.195-205
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• 2023

The contact acoustic emission (AE) monitoring system is time-consuming and costly for monitoring concrete structures in large scope, in addition, the great difference in acoustic impedance between air and concrete makes the detection process inconvenient. In this work, we broaden the conventional AE source localization method for concrete to the non-contact (air-coupled) micro-electromechanical system (MEMS) microphones array, which collects the energy-rich leaky Rayleigh waves, instead of the relatively weak P-wave. Finite element method was used for the numerical simulations, it is shown that the propagation velocity of leaky Rayleigh waves traveling along the air-concrete interface agrees with the corresponding theoretical properties of Lamb wave modes in an infinite concrete slab. This structures the basis for implementing a non-contact AE source location approach. Based on the experience gained from numerical studies, experimental studies on the proposed air-coupled AE source location in concrete slabs are carried out. Finally, it is shown that the locating map of AE source can be determined using the proposed system, and the accuracy is sufficient for most field monitoring applications on large plate-like concrete structures, such as tunnel lining and bridge deck.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.855-859
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• 2004

The Japanese National Project "Carbon Nanotube FED" is developing a high image-quality and low power-consumption field emission display (FED) by applying carbon nanotube (CNT) to the electron source. A uniform electron source with a flat-film CNTs and fine structure triodes Fir suppressing the deviation of emission is required. For realizing an FED panel, it is also necessary to develop the glass-bulb technologies for vacuum sealing, and display technologies for driving the panel by circuit electronic and for evaluating the picture quality by measuring. By achieving these technologies, an FED compatible with conventional Cathode Ray Tubes (CRTs) will be realized.

• Journal of Climate Change Research
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• v.7 no.4
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• pp.443-450
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• 2016

The major greenhouse gases (GHGs) in agricultural sector are methane ($CH_4$), nitrous oxide ($N_2O$), carbon dioxide ($CO_2$). GHGs emissions are estimated by pertinent source category in a guideline book from Intergovernmental Panel on Climate Change (IPCC) such as methane from rice paddy, nitrous oxide from agricultural soil and crop residue burning. The methods for estimation GHGs emissions in agricultural sector are based on 1996 and 2006 IPCC guideline, 2000 and 2003 Good Practice Guidance. In general, GHG emissions were calculated by multiplying the activity data by emission factor. The total GHGs emission is $10,863Gg\;CO_2-eq$. from crop cultivation in agricultural sector in 2013. The emission is divided by the ratio of greenhouse gases that methane and nitrous oxide are 64% and 34%, respectively. Each gas emission according to the source categories is $7,000Gg\;CO_2-eq$. from rice paddy field, $3,897Gg\;CO_2-eq$. from agricultural soil, and $21Gg\;CO_2-eq$. from field burning, respectively. The GHGs emission in agricultural sector had been gradually decreased from 1990 to 2013 because of the reduction of cultivation. In order to compare with indirect emissions from agricultural soil, each emission was calculated using IPCC default factors (D) and country specific emission factors (CS). Nitrous oxide emission by CS applied in indirect emission, as nitrogen leaching and run off, was lower about 50% than that by D.

• Current Research on Agriculture and Life Sciences
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• v.32 no.4
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• pp.215-223
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• 2014

This study examines the contribution level of greenhouse gas(GHG) emission reduction and installation costs of renewable energy facilities. The GHG emission forecasts and industrial structures in the 16 regions of Korea are then analyzed to identify the proper supply of renewable energy sources for each region. The results show that water power is the most effective and efficient renewable energy source to reduce GHG emissions, followed by sunlight, wind power, geothermal heat, and solar heat, respectively. The 16 regions are then categorized into 4 groups based on their GHG emission forecast and industrial structure: high emission and manufacturing group, low emission and manufacturing group, low emission and service group, and high emission and service group. The proper supply of renewable energy sources for each group is then determined based on the contribution level and cost efficiency of GHG emission reduction.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.837-842
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• 2004

The positions of rotating sound sources have been localized by experiments with the Doppler effects removed. In order to do-Dopplerize the sound signals emitted from moving sources, two kinds of signal reconstruction methods were applied. One is the forward propagation method and the other is the backward propagation method. Forward propagation method analyze the source emission time based on the instantaneous distance between sensors and the assumed source position, then the signals are reconstructed with respect to the emission time. On the other hand, the backward method uses time delay to do-Dopplerize the acquired data for the received time of reference. In both techniques, the reconstructed signal data were processed using beamforming algorithm to produce power distributions at the frequency of interest. Experiments have been carried out for varying frequencies, rotating speeds and the object distances. Forward propagation method has shown better performance in locating source position than the backward propagation method.

• Journal of Environmental Science International
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• v.8 no.1
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• pp.135-144
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• 1999

Air quality modeling about coastal urban region such as Pusan shoud be consider shipping source emmited from ships anchoraging and running. It has been proved at our previous studies that the ratios of air pollutants emission amount in coastal area to inland are 12.2% for NO$_2$ and 11.7% for $SO_2$ and the air qualify of coastal urban area consierably counts on ships. Also the dispersion pattern of the all pollutants followed local circulation system in this region. Therefore this study has been developed air quality model which can describe the formation, transport, transformation and deposition processes of air pollutants considering shipping source. Currently, restriction for emission amount of ships does not exist, so our study will be useful to set the omission standard and for devising air quality policy in coastal urban region.