• Geomechanics and Engineering
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• v.14 no.2
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• pp.203-209
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• 2018

Reliable estimation of compressive as well as tensile in-situ stresses is critical in the design and analysis of underground structures and openings in rocks. Kaiser effect technique, which uses acoustic emission from rock specimens under cyclic load, is well established for the estimation of in-situ compressive stresses. This paper investigates the Kaiser effect on marble specimens under cyclic uniaxial compressive as well as cyclic uniaxial tensile conditions. The tensile behavior was studied by means of Brazilian tests. Each specimen was tested by applying the load in four loading cycles having magnitudes of 40%, 60%, 80% and 100% of the peak stress. The experimental results confirm the presence of Kaiser effect in marble specimens under both compressive and tensile loading conditions. Kaiser effect was found to be more dominant in the first two loading cycles and started disappearing as the applied stress approached the peak stress, where felicity effect became dominant instead. This behavior was observed to be consistent under both compressive and tensile loading conditions and can be applied for the estimation of in-situ rock stresses as a function of peak rock stress. At a micromechanical level, Kaiser effect is evident when the pre-existing stress is smaller than the crack damage stress and ambiguous when pre-existing stress exceeds the crack damage stress. Upon reaching the crack damage stress, the cracks begin to propagate and coalesce in an unstable manner. Hence acoustic emission observations through Kaiser effect analysis can help to estimate the crack damage stresses reliably thereby improving the efficiency of design parameters.

• Journal of Korean Society for Atmospheric Environment
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• v.3 no.1
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• pp.55-64
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• 1987

Actual driving pattern of each motor vehicle type was measured and analyzed in Seoul area and vehicle emission rate was measured and traffic data were used to estimate vehicular emission factor and motor vehicle-related air pollutant emission. The analysis of contribution ratio of each vehicle type showed that LPG taxi's took 38.1% of total vehicular CO, gasoline passenger cars 37.5%, therefore, these cars are major sources of CO, gasoline passenger cars took 45.4% of total vehicular HC, motorcycles 25.3%, LPG taxi's 16.2%, so motorcycles can be said to play an important role in HC emission. For NOx, buses and trucks were thought to be major sources as buses took 36.8% and truck 26.4%. Diesel vehicles, on the other hand, took most $SO_2$ and particulate matter emission. Total emission from motor vehicles in Seoul was estimated to be 547 t/day of CO, 68t/day of HC, 163t/day of NOx, 18t/day of $SO_2$ and 19t/day of paticulate matter.

• Journal of Animal Environmental Science
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• v.4 no.2
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• pp.183-191
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• 1998

This study was carried out to elucidate the correlation between Germination Index(G.I.) and CO2 emission for evaluation of the maturity of compost products. 13 compost samples was used for this experiment. The G.I. test was carried out on the basis of T-N 200ppm. As a result of this research, we found that CO2 emission method was good simple indicator for evaluation of maturity of compost materials, in spite of G.I. The obtain results are summarized as follows ; 1. The correlation value between the G.I. and the CO2 emission was R2 = 0.776. 2. The correlation value between EC(Electric Conductivity) and G.I. was R2 =0.7. 3. The equation calculated from G.I. and CO2 emission was G.I. = -16.7(InCO2) - 6.87. 4. From these results, we found the possibility of estimation for the value of G.I.(T-N 200ppm) from CO2 emission volume under specific condition.

• Journal of Korean Society for Atmospheric Environment
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• v.15 no.3
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• pp.317-325
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• 1999

The demand of diesel engine on the construction equipment has been rapidly increased because of high thermal efficiency and fuel economy. The exhaust emission from nonroad vehicles equipped with diesel engine such as construction equipment, ship, and agricultural equipment, etc. Which are known to be harmful to human health and environment, has not been regulated in our country. But the regulation for nonroad vehicle has been already progressed in advanced country. So we investigated the contribution ratio of air pollution by construction equipment in order to establish the exhaust emission management strategy for nonroad vehicle. Based on the statistical data for construction equipment, 5 kinds of equipment are selected and tested in the engine dynamometer to determine the emission factor. And the amount of air pollutant from construction equipment are calculated by using of the emission factor and recommended exhaust emission standard for construction equipment.

• Proceedings of KOSOMES biannual meeting
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• 2018.06a
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• pp.8-8
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• 2018

• Proceedings of KOSOMES biannual meeting
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• 2018.06a
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• pp.126-126
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• 2018

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2007.10a
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• pp.54-55
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• 2007

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2004.11a
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• pp.143-144
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• 2004

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2009.06a
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• pp.194-195
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• 2009

According to the issue "global warming", many regulations and agreements with countries in the world are becoming set and it is being fulfill now. Under the progress of Post Kyoto Protocol agreement, It will be sure that Korea rave a duty to reduce $CO_2$ emission from 2013. For them, Korea have to make a strategies about the Climatic Change Convention for all industries. Recently, a great attention about $CO_2$ emission in the world is focused on port, shipping line and airline. Most countries are establishing policies to prevent environment from these industry fields, but Korea has not yet made for them. Thus, Korea need to collect $CO_2$ emission data not only the routes of container from port but also activities in the port. In this paper, an estimation of $CO_2$ emission under the route of container transportation at Korea by using O/D analysis will be addressed. And then, it will be used to make a optimal routes of container transportation which can reduce $CO_2$ emission in future.

• Journal of Korean Society of Rural Planning
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• v.27 no.4
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• pp.33-41
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• 2021

Ammonia emission from the agricultural sector contributes almost 78% of total ammonia emission in Korea. The current ammonia emission estimation method from fertilizer application has high uncertainty and needs to be improved. In this study, we propose an improvement method for estimating the amount of ammonia emission from agricultural land with improved spatiotemporal resolution using Farm Manager Registration Information System and criteria for the fertilizer. We calculated ammonia emissions by utilizing the 2020 cultivation area provided by Farm Manager Registration Information System for 55 kinds of upland crops cultivated in the field area of the farmland. As a result, soybeans were the most cultivated field crop in 2020, and the area of cultivated land was surveyed at about 77,021 ha, followed by sweet potatoes 22,057 ha, garlic 20004 ha, potatoes 17,512 ha, and corn 16,636 ha. The month with the highest ammonia emissions throughout the year was calculated by emitting 590.01 ton yr-1 in May, followed by 486.55 ton yr-1 in March. Hallim-eup in Jeju showed the highest ammonia emission at 117.50 ton yr-1.