• Nuclear Engineering and Technology
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• v.55 no.11
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• pp.4282-4286
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• 2023

Nuclear energy is estimated by the machine learning method as the mathematical quantifications where neural networking is the major algorithm of the data propagations from input to output. As the aspect of nuclear energy, the other energy sources of the traditional carbon emission-characterized oil and coal are compared. The artificial intelligence (AI) oriented algorithm like the intelligence of a robot is applied to the modeling in which the mimicking of biological neurons is utilized in the mathematical calculations. There are graphs for nuclear priority weighted by climate factor and for carbon dioxide mitigation weighted by climate factor in which the carbon dioxide quantities are divided by the weighting that produces some results. Nuclear Priority and CO2 Mitigation values give the dimensionless values that are the comparative quantities with the normalization in 2010. The values are 1.0 in 2010 of the graphs which are changed to 24.318 and 0.0657 in 2040, respectively. So, the carbon dioxide emissions could be reduced in this study.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.3
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• pp.125-132
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• 2007

The purpose of present paper is to investigate a fracture characteristics of the finite-width single-edge-notch(SEN) carbon fiber/epoxy reinforced plastics(CFRP) plates by using an acoustic emission(AE). Uni-directionally oriented 10 plies CFRPs specimen which had different notch length were prepared for monotonic tensile test. Matrix cracking appeared over whole testing process and fiber breaking appeared later on mainly Load distribution factor of the matrix confirmed that increased according as increases of plate width ratio. The amplitude distribution of AE signal from a specimens is an aid to the determination of the different fracture mechanism such as matrix cracking, disbonding, interfacial delamination, fiber pull-out, fiber breaking, and etc. In the result of AE amplitude distribution analysis, matrix cracking, fiber disbonding or interfacial delamination, and fiber pull-out or fiber breaking signal correspond to <65dB, <75dB, and <90dB respectively, Also, changes of the slope of cumulative AE energy represented crazing phenomena or degradation of materials.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1206-1209
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• 2006

Carbon nanotubes (CNTs) have been significantly used for the field emitters for display applications. However, the lifetime of CNT emitters which are formed by screen printing technique is not guaranteed yet, because the constituents in CNT paste affect the lifetime of CNTs. The CNT pastes for screen printing are normally composed of organic vehicles (nitro cellulose, ethyl cellulose, etc) and additives (glass frits, ITO, etc) with CNTs. In this study, the effects of constituents in CNT pastes on the lifetime and emission characteristics of CNTs were investigated by thermal and electrical analysis. Use of glass frits worsened the lifetime and electron emission of CNTs. However, an addition of ITO to CNT paste rather improved the lifetime of CNTs. Degradation of CNTs was small when nitro cellulose was used in CNT paste as an organic vehicle.

• Journal of the Korean Solar Energy Society
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• v.31 no.1
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• pp.23-30
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• 2011

International cooperation to reduce greenhouse gas emissions is expected to provide a big crisis and a great opportunity at the same time for our industry that heavily consumes energy. To cope actively with the international environmental regulation, such as the Framework Convention on Climate Change, quantitative measurement of the volume of greenhouse gases emitted by various industries and quantitative prediction of the greenhouse gas emissions of the future are becoming more important than anything else at the national level. This study aims to propose the calculation process of carbon dioxide($CO_2$) emission for building in life cycle. This paper describes and compares 9 different tool for environmental load estimation with LCA. This study proposed the calculation process for quantitatively predicting and assessing $CO_2$ emissions during the life cycle of buildings based on the life cycle assessment(LCA). The life cycle steps of buildings were divided into the design/supervision, new construction, repair, renovation, use of operating energy in buildings, maintenance, and reconstruction stage in the life cycle inventory analysis and the method of assessing the environmental load in each stage was proposed.

• Journal of Korean Society of Forest Science
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• v.112 no.2
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• pp.188-194
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• 2023

This study aimed to derive the basic wood density, one of several carbon emission factors, for carbon accounting of bamboo forests in Korea. Bamboo is mainly distributed in Jeollanam-do and Gyeongsangnam-do provinces, and 101 sample trees were selected for each of the three species (Phyllostachys nigra var. henonis, P. bambusoides, and P. pubescens). The basic wood density derivation used the KS F 2098 method. The measurements showed that the basic wood density was 0.83 g/cm³ for P. nigra var. henonis, 0.81 g/cm³ for P. bambusoides, and 0.72 g/cm³ for P. pubescens. However, the bamboo distribution area in Korea is not very large, and P. pubescens grows in one area only. Therefore, the basic wood density that can be applied to bamboo was 0.79 g/cm³. Evaluation of the uncertainty of the extracted basic wood density showed a very low value of 1.61%, which confirmed the reliability of the basic wood density derived from this analysis. The basic wood density, biomass expansion factor, and root-to-shoot ratio were used to calculate the carbon storage capacity of one bamboo plant and expanded to calculate the capacity for a hectare of bamboo. Carbon storage and absorption of bamboo were calculated by applying a carbon-emission factor, such as the basic wood density. These study results are expected to contribute to the carbon-neutral policy and forest management direction in Korea.

• Carbon letters
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• v.20
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• pp.1-9
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• 2016

Activated carbon was synthesized from coconut shells. The Brunauer, Emmett and Teller surface area of the synthesized activated carbon was found to be 1640 m²/g with a pore volume of 1.032 cm³/g. The average pore diameter of the activated carbon was found to be 2.52 nm. By applying the size-strain plot method to the X-ray diffraction data, the crystallite size and the crystal strain was determined to be 42.46 nm and 0.000489897, respectively, which indicate a perfect crystallite structure. The field emission scanning electron microscopy image showed the presence of well-developed pores on the surface of the activated carbon. The presence of important functional groups was shown by the Fourier transform infrared spectroscopy spectrum. The adsorption of methyl orange onto the activated carbon reached 100% after 12 min. Kinetic analysis indicated that the adsorption of methyl orange solution by the activated carbon followed a pseudo-second-order kinetic mechanism (R² > 0.995). Therefore, the results show that the produced activated carbon can be used as a proper adsorbent for dye containing effluents.

• Journal of Biosystems Engineering
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• v.28 no.3
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• pp.225-230
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• 2003

This study was carried out to analyze the environmental variation of layer house at Iowa State in the USA. The analyzed seasons for this study were summer and winter. Analyzing factors are inside temperature and relative humidity, carbon dioxide concentration, ammonia concentration and emission. All factors were collected every 30 second from each house with portable monitoring units. In this study, two types of laying hen houses were monitored at the same season. One was a manure belt house, the other was a high-rise house. In order to estimate the ventilation rates of the laying hen houses, carbon dioxide concentration balance was used in this study. Ammonia concentrations and emission rates of the manure belt house are much lower than those of the high rise house. Daily mean ammonia concentrations in the manure belt house and high-rise house ranged from 3 to 7 ppm and 5 to 34 ppm, respectively. The daily ammonia emission rates averaged 0.68g/h$\cdot$500kg and 0.73g/h$\cdot$500kg for the manure belt house and 0.93g/h$\cdot$500kg and 2.89g/h$\cdot$500kg for the high-rise house in summertime and wintertime, respectively. Summertime is associated with much higher ammonia emission rates than wintertime because of much higher ventilation rates and ambient air temperature, even though the concentrations may be lower.

• Korean Journal of Organic Agriculture
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• v.20 no.4
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• pp.503-518
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• 2012

Korean type of no-tillage cultivation method which was applied on this study used the ridge and the furrow and constantly recycling them as it was suitable for Korea's weather and farming conditions. This no-tillage cultivation was reported to have little negative impact such as reduction of production (Kwon et al., 1997). In addition, it was found to have a lot of benefits as it requires less agro-materials and energy costs as well as shortened working hours because tillage operation is not needed. (Yang et al., 2012). According to an analysis, no-tillage cultivation can reduce greenhouse gas emissions by $344.7kgCO^2$ (58%) in every 10a ($1,000m^2$) compared to ordinary pepper farming technique (Korea averages). Direct-indirect reduction effects from using fertilizer and using less amount of energy were 92% and 44% respectively both of which can be considered very high. Besides the direct effects of no-tillage cultivation, soil management using no-tillage technique raises carbon sequestration effect on soil as time goes on (West & Marland, 2002), that is why the technique is expected to have constant carbon emission reduction effect. For theses reasons, distribution and expansion of Korean type no-tillage cultivation are expected to play a role as major agro-green technologies for achieving our goal of reducing greenhouse gas emissions in agricultural sector.

• Journal of the Society of Disaster Information
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• v.17 no.1
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• pp.165-175
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• 2021

Purpose: The purpose of this study is to quantitatively present the carbon dioxide(CO₂) emission change according to the application of autonomous driving technology at the network level for waste vehicles in the metropolitan area. Method: The target year was set to 2030, and the analysis method estimated the carbon dioxide (CO₂) emissions for each road link through user equilibrium assignment when unapplied scenario. The application scenario performed traffic assignment using route data on the premise that the group was running in accordance with the application of autonomous driving technology to waste vehicles. In addition, the other means estimated the carbon dioxide emissions through user balance allocation by reflecting the results of the waste vehicle allocation. Result: As a result of the analysis, carbon dioxide(CO₂) emissions were found to be reduced by about 56.9ton/day from the national network level, and the Seoul metropolitan area was analyzed to be reduced by about 54.7ton/day. Conclusion: This study quantitatively presented environmental impacts among various social effects that autonomous driving technology will bring, and in the future, development of various analytical methodologies and related studies should be continuously conducted.

• Journal of Korean Society for Atmospheric Environment
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• v.28 no.5
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• pp.556-570
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• 2012

The Low Carbon Path Calculator is an excel-based model to project greenhouse gas emissions from 2009 to 2050, which is based on the 2050 Pathways Calculator developed by the UK Department of Energy and Climate Change (DECC). Scenarios are developed to reduce GHG emissions in Korea at 50% based on 2005 levels by 2050 using a Low Carbon Path Calculator. They were classified in four different cases, which are high renewable, high nuclear, high CCS and mixed option scenarios. The objectives of this study are to compare scenarios in terms of GHG emissions, final energy, primary energy and electricity generation and examine the usefulness of that model in terms of identifying pathways towards a low carbon emission society. This model will enhance the understanding of the pathways toward a low carbon society and the level of the climate change policy for policy makers, stakeholders, and the public. This study can be considered as a reference for developing strategies in reducing GHG emissions in the long term.