• Journal of Energy Engineering
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• v.17 no.2
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• pp.54-66
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• 2008

After the Kyoto Protocol has been ratified in Feb. 16 2005, the developed countries which is involved in Annex-1 have tried to mitigate GHG to the reduction objective. To accomplish this objective, EU developed EU-ETS, CDM project, and so on. Korea has faced pressure to be a member of Annex-1, because Korea and Mexico are only non-Annex-1 countries in the OECD nations. In this study, we simulated power plant expansion plan and calculated $CO_2$ emission with changing Carbon Tax. Especially, we focused on the competitiveness of IGCC and carbon capture technology. In our result, even though carbon tax rise, nuclear power plant does not always increase, it increase up to minimum load. LNG combined cycle power plants substitute the coal fired power plants. If there are many alternatives like IGCC, these substitute a coal fired power plant and we can reduce more $CO_2$ and save mitigation cost.

• Journal of the Korean Society for Marine Environment & Energy
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• v.6 no.2
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• pp.46-53
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• 2003

In order to analyze the movement characteristics of suspended solid(SS) in harbor construction, we investigate the generation and movement processes of the SS for the landfill construction by direct casting method and the grab dredging construction which is the most frequent process in harbor construction. We find that the SS is generated into a very high concentration right after the direct casting of landfill soil and continued up to 60 minutes in the landfill construction using the direct casting method with dredged materials by a ship of 700-tonnage. In the grab dredging construction, the SS is generated in a high density of concentration near at its source regardless of water depth, formed belt and diffused up to 700m along the trajectory of tidal current. Based on the result of the present study, it is recommended for the mitigation of SS generation that the silt protector be deployed near at construction site close enough to block the diffusion of SS and the body length of silt protector be long enough to mitigate the SS diffusion in the bottom layer.

• Korean Journal of Environmental Biology
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• v.31 no.4
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• pp.471-477
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• 2013

Biochar amendment to agricultural soil is regarded as a promising option to mitigate climate change and enhance soil quality. It could sequester more carbon within the soil system and increase plant yield by changing soil physicochemical characteristics. However, sustainable use of biochar requires comprehensive environmental assessment. In this sense, it is important to measure additional greenhouse gas emission from soils after biochar addition. We investigated emissions of $CO_2$, $N_2O$, and $CH_4$ from incubated soils collected from rice paddy and cultivated grassland after amendment of 3% biochar (wt.) produced from rice chaff. During incubation, soils were exposed to three wet-dry cycles ranging from 5~85% soil gravimetric water content (WC) to investigate the changes in effect of biochar when influenced by different water levels. The $CO_2$ emission was reduced in biochar treatment compared to the control at WC of 30~70% both in rice paddy and grassland soils. This indicates that biochar could function as a stabilizer for soil organic carbon and it can be effective in carbon sequestration. The $N_2O$ emission was also reduced from the grassland soil treated with biochar when WC was greater than 30% because the biochar treated soils had lower denitrification due to better aeration. In the rice paddy soil, biochar addition resulted in decrease in $N_2O$ emission when WC was greater than 70%, while an increase was noted when WC was between 30~70%. This increase might be related to the fact that available nutrients on biochar surface stimulated existing nitrifying bacterial community, resulting in higher $N_2O$ emission. Overall results imply that biochar amendment to agricultural soil can stabilize soil carbon from fast decomposition although attention should be paid to additional $N_2O$ emission when biochar addition is combined with the application of nitrogen fertilizer.

• Journal of Animal Science and Technology
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• v.60 no.11
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• pp.27.1-27.8
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• 2018

Background: Enteric methane ($CH_4$) accounts for about 70% of total $CH_4$ emissions from the ruminant animals. Researchers are exploring ways to mitigate enteric $CH_4$ emissions from ruminants. Recently, nano zinc oxide (nZnO) has shown potential in reducing $CH_4$ and hydrogen sulfide ($H_2S$) production from the liquid manure under anaerobic storage conditions. Four different levels of nZnO and two types of feed were mixed with rumen fluid to investigate the efficacy of nZnO in mitigating gaseous production. Methods: All experiments with four replicates were conducted in batches in 250 mL glass bottles paired with the ANKOM$^{RF}$ wireless gas production monitoring system. Gas production was monitored continuously for 72 h at a constant temperature of $39{\pm}1^{\circ}C$ in a water bath. Headspace gas samples were collected using gas-tight syringes from the Tedlar bags connected to the glass bottles and analyzed for greenhouse gases ($CH_4$ and carbon dioxide-$CO_2$) and $H_2S$ concentrations. $CH_4$ and $CO_2$ gas concentrations were analyzed using an SRI-8610 Gas Chromatograph and $H_2S$ concentrations were measured using a Jerome 631X meter. At the same time, substrate (i.e. mixed rumen fluid+ NP treatment+ feed composite) samples were collected from the glass bottles at the beginning and at the end of an experiment for bacterial counts, and volatile fatty acids (VFAs) analysis. Results: Compared to the control treatment the $H_2S$ and GHGs concentration reduction after 72 h of the tested nZnO levels varied between 4.89 to 53.65%. Additionally, 0.47 to 22.21% microbial population reduction was observed from the applied nZnO treatments. Application of nZnO at a rate of $1000{\mu}g\;g^{-1}$ have exhibited the highest amount of concentration reductions for all three gases and microbial population. Conclusion: Results suggest that both 500 and $1000{\mu}g\;g^{-1}$ nZnO application levels have the potential to reduce GHG and $H_2S$ concentrations.

• Korean Journal of Agricultural and Forest Meteorology
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• v.11 no.3
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• pp.100-110
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• 2009

'Hongro' is one of the important mid-season apple cultivars bred in Korea. The recent occurrence of water core in Hongro and the consequent problems motivated this study. The objectives of our study were to investigate the influence of air temperature during the growing period on water core occurrence in Hongro and to provide methods to mitigate its impact. Based on our field experiments for three years, the results indicated that the occurrence of water core disorder was due to the prolonged exposure to high temperature ($T_a$) of >$30^{\circ}C$ during the ripening period. The rates of occurrence of water core disorder were higher in the fruit whose weight was more than 300g or those located outside the tree canopy and thus exposed to stronger solar radiation. In terms of mitigating the water core occurrence, the application of spraying $CaCl_2$ four times from late July to August was effective. Furthermore, between 1 and 15 August when the rate of occurrence was high with $T_a$ (from 3:00 to 5:00 p.m.) >$30^{\circ}C$, the micro-water sprinkling for 30 minutes starting at 6:00 p.m. with a supplementary spray conducted two hours after the first application drastically reduced the water core occurrence.

• Korean Journal of Agricultural and Forest Meteorology
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• v.22 no.2
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• pp.92-101
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• 2020

To prevent and mitigate damage to farms due to heavy snowfall, snow weight information should be provided in addition to snow depth. This study reviews four formulae regarding snow density and weight used in extant studies and applies them in Suwon area to estimate snow weight in Korea. We investigated the observed snow depth of 94 meteorological stations and automatic weather stations (AWS) data over the past 30 years (1988-2017). Based on the spatial distribution of snow depth by area in Korea, much of the fresh snow cover, due to heavy snowfall, occurred in Jeollabuk-do and Gangwon-do. Record snowfalls occurred in Gyeongsangbuk-do and Gangwon-do. However, the most recent heavy snowfall in winter occurred in Gyeonggi-do, Gyeongsangbuk-do, and Jeollanam-do. This implies that even if the snow depth is high, there is no significant damage unless the snow weight is high. The estimation of snow weight in Suwon area yielded different results based on the calculation method of snow density. In general, high snow depth is associated with heavy snow weight. However, maximum snow weight and maximum snow depth do not necessarily occur on the same day. The result of this study can be utilized to estimate the snow weight at other locations in Korea and to carry out snow weight prediction based on a numerical model. Snow weight information is expected to aid in establishing standards for greenhouse design and to reduce the economic losses incurred by farms.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.5
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• pp.227-236
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• 2016

This study tested the effects of stress on smartphone addiction via depression and self-efficacy among college students, and the analysis results were as follows: setting mediator and extra variables significantly correlated with the criterion variable as covariates and applying the regression analysis and SPSS Macro as well as bootstrapping method, to verify the mediating effects of depression and self-efficacy in stress and smartphone addiction. This study analyzed the direct effects of stress on the depression, self-efficacy, and smartphone addiction of college students and found that stress had direct effects on their depression and self-efficacy and also indirect effects on their smartphone addiction via depression and self-efficacy. Both depression and self-efficacy had dual and partial mediating effects on the influences of stress on their smartphone addiction. Stress had significant dual mediating effects on their smartphone addiction via the indirect paths of depression and self-efficacy, and high stress also had significant direct effects on their smartphone addiction, thus validating the dual mediation model. These findings demonstrate the need to develop programs to mitigate the stress and depression of college students and enhance their self-efficacy in order to reduce their smartphone addiction.

• Journal of the Korean Institute of Landscape Architecture
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• v.43 no.2
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• pp.23-29
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• 2015

To fulfill the need for reuse indigenous tree to mitigate the elimination of nature forests due to road construction, one representative method for this reuse is to transplant them and re-establish in similar conditions. In order to investigate the transplant and establishment of indigenous tree, a correlation and regression analysis was conducted by species and tree size. Data were collected for 6 years(2008~2013) in 7 construction sites in cooperation with the Korea Expressway Corporation. Regarding the transplanted indigenous trees status, the success rate of transplant was 15,519(69%) of 22,521. The tree most transplanted was Pinus densiflora(15,562), followed by Quercus spp.(6,156), Prunus sargentii(235), and P. thunbergii(154). P. densiflora and P. thunbergii belong to the conifer group while Quercus spp., Prunus sargentii belong to the broadleaf group. As a result of a contrast test, the conifer group had a significantly lower success rate of transplant than the broadleaf group. In the relation of root collar diameter and success rate of transplant, there was the tendency that the larger the root collar diameter, the lower the success rate of transplant. This study demonstrated that there is a strong negative correlation between the two factors(r=-0.730, p>0.000). The predicted regression equation of the success rate of transplant was Y= -0.811X+88.627(X: root collar diameter, Y: success rate of transplant) and the $R^2$ value for the linear equation was 0.532.

• Journal of the Korean Institute of Landscape Architecture
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• v.43 no.2
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• pp.73-86
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• 2015

This study aimed to identify influencing factors such as job environment, job characteristics, and job competency as they are related to newcomer turnover intentions in the construction of landscape architecture, Korea. The results based on statistical analyses are follows as: The turnover experience of newcomers in the field of landscape architecture construction was 54.5%, about 1.6 times higher than in other fields. The influencing factors among newcomer turnover intentions in the construction of landscape architecture were workload(p<0.01), job suitability, and personal relations(p<0.01), while in job autonomy, work conditions, job competency, job identity, job variety, and job compensation were not statistically significant. This study found that key important factors of dependent variables that conceptually explain the influence of turnover intentions among newcomers differed between the construction of landscape architecture and other fields. The most important factors in turnover intention were workload>personal relationship>job suitability among independent factors. This study implied that efforts for improvement are needed in areas of workload, personal relations, and job suitability to mitigate newcomer turnover intentions so as to establish common and personal goals in the field of landscape architecture construction because turnover intention could lead losses in human resources, time, economy, and psychological health. In conclusion, this study suggested the importance of efforts for human resource management to reduce turnover intentions among newcomers in the field of landscape architecture construction.

• Journal of Navigation and Port Research
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• v.39 no.6
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• pp.529-538
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• 2015

This paper was intended to empirically identify problems with recreational sea fishing park facilities installed to help reinvigorate local economy of fishing villages in order to mitigate shortage of fishing facilities amid an increase in sea fishers and spur evolution of sea fishing into a marine leisure activity, on which basis this researcher presented direction for facility planning which is deemed necessary to map out the plan for sea fishing parks, along with measures designed to improve sea fishing park facilities. To analyze the problems related to sea fishing park facilities, we conducted a survey on facility operations involving 9 sea fishing parks and 2 sea ranches and had an investigative interview with facility manager. Moreover, a survey was conducted of fishers in 25 sea fishing places, including sea fishing park, fishing experience village, etc., in order to investigate their demand for facilities. The results of survey suggested that there was a significant demand for expansion of amenities such as safety facilities, toilets, lounge facilities, etc., which can accommodate the increase in the number of people fishing with family. Furthermore, the results showed that there was a huge demand for introduction of facilities aiding leisure activities in addition to facilities for fishing activities including education facilities such as fishing site at the corner exclusive for beginners, experiential facilities, camping site, seaside park, promenade, etc. Thus, sea fishing park should be the complex leisure space with a focus on fishing activities and requires facility configuration and facility planning suited to activity requirements within fishing park.