• Korean Journal of Agricultural and Forest Meteorology
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• v.25 no.1
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• pp.1-16
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• 2023

As the Intergovernmental Panel on Climate Change (IPCC) emphasized the transition to a carbon-neutral society globally by 205 0, major countries such as Korea, Japan, and Europe declared carbon-neutral goals. The agricultural sector is a carbon-absorbing sector, and its importance has increased as the General Assembly of the Parties to the Climate Change Convention (COP 26) held in the UK in November 2021 emphasized the role of agriculture to discuss climate change. However, GHG reduction projects in the agricultural sector are not properly monitored considering the domestic situation, and a system for quantitative evaluation of the effectiveness or basis of implementing the project program is not in place. Therefore, a priori study is needed to understand the current status of existing policies and to review matters that need to be improved in order to facilitate policy design, implementation, and monitoring for GHG reduction in the agricultural sector. The purpose of this study is to examine the opinions of stakeholders by applying a semi-structured interview method to diagnose the current status of Korea's GHG reduction policy in the agricultural sector and identify factors that hinder policy implementation. As a result of the semi-structured interview, this study presented factors that hinder the promotion of GHG reduction policies in the agricultural sector according to four types of data and technology, finance, institutions, and perceptions. Some stakeholders also stressed that the pilot project could be helpful as a way to comprehensively consider the implications of this study, such as securing technology data, establishing a system for verifying effectiveness, and providing incentives and promoting them. Rather than drawing specific conclusions, this study is an exploratory study that diagnoses and reviews the progress of GHG reduction policies, and it can be used as useful basic data if it secures enough interview respondents and balances the number of samples by group.

• Economic and Environmental Geology
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• v.56 no.2
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• pp.139-153
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• 2023

This study aimed to understand the spatiotemporal variations in nitrogen content in the Gyeongan stream along the main stream and at the discharge points of the sub-basins, and to identify the origin of the nitrogen. Field surveys and laboratory analyses, including chemical compositions and isotope ratios of nitrate and boron, were performed from November 2021 to November 2022. Based on the flow duration curve (FDC) derived for the Gyeongan stream, the dry season (mid-December 2021 to mid-June 2022) and wet season (mid-June to early November 2022) were established. In the dry season, most samples had the highest total nitrogen(T-N) concentrations, specifically in January and February, and the concentrations continued to decrease until May and June. However, after the flood season from July to September, the uppermost subbasin points (Group 1: MS-0, OS-0, GS-0) where T-N concentrations continually decreased were separated from the main stream and lower sub-basin points (Group 2: MS-1~8, OS-1, GS-1) where concentrations increased. Along the main stream, the T-N concentration showed an increasing trend from the upper to the lower reaches. However, it was affected by those of the Osan-cheon and Gonjiamcheon, the tributaries that flow into the main stream, resulting in respective increases or decreases in T-N concentration in the main stream. The nitrate and boron isotope ratios indicated that the nitrogen in all samples originated from manure. Mechanisms for nitrogen inflow from manure-related sources to the stream were suggested, including (1) manure from livestock wastes and rainfall runoff, (2) inflow through the discharge of wastewater treatment plants, and (3) inflow through the groundwater discharge (baseflow) of accumulated nitrogen during agricultural activities. Ultimately, water quality management of the Gyeongan stream basin requires pollution source management at the sub-basin level, including its tributaries, from a regional context. To manage the pollution load effectively, it is necessary to separate the hydrological components of the stream discharge and establish a monitoring system to track the flow and water quality of each component.

• The Journal of Engineering Geology
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• v.33 no.3
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• pp.371-388
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• 2023

A stratum with a complex composition and a distributed low-permeability soil layer is difficult to remediate quickly because the soil remediation does not proceed easily. For efficient purification, the permeability should be improved and the soil remediation agent (H₂O₂) should be injected into the contaminated section to make sufficient contact with the TPH (Total petroleum hydrocarbons). This study analyzed a method for crack formation and effective delivery of the soil remediation agent based on pneumatic fracturing, plasma blasting, and vacuum suction (the PPV method) and compared its improvement effect relative to chemical oxidation. A demonstration test confirmed the effective delivery of the soil remediation agent to a site contaminated with TPH. The injection amount and injection time were monitored to calculate the delivery characteristics and the range of influence, and electrical resistivity surveying qualitatively confirmed changes in the underground environment. Permeability tests also evaluated and compared the permeability changes for each method. The amount of soil remediation agent injected was increased by about 4.74 to 7.48 times in the experimental group (PPV method) compared with the control group (chemical oxidation); the PPV method allowed injection rates per unit time (L/min) about 5.00 to 7.54 times quicker than the control method. Electrical resistivity measurements assessed that in the PPV method, the diffusion of H₂O₂2 and other fluids to the surface soil layer reduced the low resistivity change ratio: the horizontal change ratio between the injection well and the extraction well decreased the resistivity by about 1.12 to 2.38 times. Quantitative evaluation of hydraulic conductivity at the end of the test found that the control group had 21.1% of the original hydraulic conductivity and the experimental group retained 81.3% of the initial value, close to the initial permeability coefficient. Calculated radii of influence based on the survey results showed that the results of the PPV method were improved by 220% on average compared with those of the control group.

• Journal of the Korea Organic Resources Recycling Association
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• v.31 no.3
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• pp.15-25
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• 2023

In this study, silicon sludge from semiconductor dicing process is recycled to fabricate silica nanoparticles, which are applied as dispersing materials for electro-responsive (ER) smart fluid. In specific, metal impurities are removed from silicon sludge by acid washing to obtain the high-purity silicon powder. And then, silica nanoparticles are synthesized by facile hydrothermal method employing the silicon powder as reactant material. To control the size of silica nanoparticles, the reaction time of hydrothermal method is varied as 8, 15, 20, and 30 hours are applied to control the size of silica nanoparticles. Sizes of silica nanoparticles are increased proportionally to the reaction time owing to the increased numbers of hydrolysis and condensation reactions. As-synthesized silica nanoparticles are prepared as electro-responsive smart fluids by dispersing into silicon oil. Silica nanoparticles synthesized by 30 hours of hydrothermal reaction (SiO₂-H30) exhibit the highest shear stress of 21.4 Pa under an applied electric field strength of 3.0kV mm^-1. Such enhancement in ER performance of SiO₂-H30 among various silica nanoparticles are attribute to the reinforcing effect originated from the mixed particle size, which allowing the formation of rigid chain-like structures. Accordingly, this study successfully propose a recycling method of silicon sludge to synthesize silica nanoparticles and their derived ER fluids, which may suggest new possibility to ESG management emphasizing the eco-friendliness.

• Journal of Korean Home Economics Education Association
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• v.35 no.2
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• pp.145-161
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• 2023

The purpose of this study is to develop a content system for the home economics curriculum that integrates Education for Sustainable Development(ESD) and provides basic material for ESD implementation in schools. In view of this, the content elements of the revised home economics curriculum for 2022 were analyzed, and a content system for the home economics curriculum, linked to ESD, was proposed based on the implications drawn from the analysis. The results are as follows. First, the three components of competencies, namely knowledge, values, and skills, were organized equally as a whole. However, the association between the content elements and key competencies in sustainability was found to be insufficient. Consequently, it is proposed that key competencies in sustainability should be cultivated integrally. Second, no content element was identified that can promote social participation. Therefore, it is proposed that solutions should be dealt with at the level of social participation. Third, the connection with Sustainable Development Goals(SDGs) was observed in only six of the 28 content elements. Wherever relevant, it is proposed to incorporate key issues related to SDGs. Fourth, the analysis confirmed that only the environmental dimension of sustainable development was considered. Therefore, it is proposed to pursue coexistence based on temporal and spatial relationship and consider the dimensions of environment, society, and economy in an integrated manner.

• Journal of the Daesoon Academy of Sciences
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• v.44
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• pp.141-175
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• 2023

This comparative study combines the methodologies of comparative research and literature review to examine Daesoon Thought. Comparative religious analysis in the social sciences, does not presuppose an a priori framework of the essence of religion because it targets various aspects of religion which are revealed within a historical field. However, it does not decompose and return to psychological or social phenomena like social sciences. In addition, with the emergence of religious pluralism, the climate of focusing on similarities between religions has already been accomplished to some degree. Furthermore, it is worth noting that many spiritual movements in modern spirituality reveal mixed or amorphous characteristics without being restricted by specific religious membership. It is time to overcome instrumentation and restore the transcendence of its original appearance even in secular humanist reasoning. It can be said that this reveals the perception that the ills and crises of modern civilization should be overcome in connection with the opening of the acquired world of Daesoon Thought. It could further be said that the main culprit of evil behavior is instrumental reason or degenerated reason rather than spirituality. Religion is the intellectual crystalline body of humankind and aims at human perfection and salvation. However, extremists in previous times amplified conflicts between religions and formed ideas suitable for their specific regions through different experiences. This generated mental rifts that proved greatly influential. At the time of initial inception, each religion confronted and fought other ideologies, but when the era of religious pluralism began, the necessity for inter-spiritual communication became urgent. It could be said that happiness is the realization of human spirituality by exploring the vision of humanism. In that case, the combined methodologies of comparative research and literature review reveal that the spirituality of Daesoon Thought would enable a humanism based on human dignity. This would be a path for seeking spirituality through human life and living as a true human being. Spiritual humanism as discussed through this study aims to share the problems of modern civilization and provide a critical view of modern civilization that shows the roots of prevailing thought are stuck in a Cartesian dualistic view of humanity and the world. The type of spiritual humanism to examined here focuses on a cosmotheandric vision by considering the spiritual return to Daoism via Daesoon Thought. This would treat human beings like heaven in alignment with Donghak ideology and honor the human dignity proposed by Daesoon Thought. It would also deliver sentient beings from suffering and to bliss in accordance with the aims of faith in Maitreya Buddha, and it would implement the Resolution of Grievances for Mutual Beneficence in fulfillment of Daesoon Thought.

• Korean Journal of Environment and Ecology
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• v.37 no.4
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• pp.259-272
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• 2023

This study set up 49 survey areas with an area of about 400 square meters in Abies koreana natural habitat to identify the species composition and vegetation structure of the A. koreana forest in the Mt. Jiri Nation Park, conducted field surveys using phytosociological methods, and performed the cluster analysis using the Two-Way Indicator Species Analysis (TWINSPAN) and Table manipulation. Subsequently, species composition analysis using the importance value, species diversity analysis, DBH analysis, sapling analysis, and similarity analysis was conducted by each cluster type. The cluster analysis classified the A. koreana forest in Mt. Jiri into five clusters, A, B, C, D, and E. The forest was divided into two clusters, Magnolia sieboldii-Dryopteris crassirhizoma-Sasa borealis and Betula ermanii-Solidago virgaurea-Calamagrostis arundinacea. The former was classified as type A and B by Cornus controversa-Hydrangea macrophylla, and the latter was classified as type E, a typical community, and a Sorbus commixta-Rhododendron mucronulatum cluster. And the S. commixta-R. mucronulatum cluster was divided into C type and D type by Picea jezoensis-Ligularia fischeri and Ainsliaea acerifolia. Through vegetation analysis, the importance value of A. koreana, Quercus mongolica, Acer pseudosieboldianum, Fraxinus sieboldiana, and B. ermanii was highly expressed in the A. koreana forest in Mt. Jiri. Regarding species diversity, the results were similar to those reported in other studies of A. koreana forests in Mt. Jiri. The analysis of diameter at breast height (DBH) showed that A. koreana dominated all layers, and the growth of saplings was also good, indicating that the dominance of A. koreana is expected to continue for a while. However, when considering the value of biodiversity that is expected to increase and threats caused by climate change, systematic preservation and management are required to respond to various threats based on continuous monitoring.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.5
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• pp.417-426
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• 2023

Rapid climate change has resulted in glacial retreat and increased meltwater inputs in the Antarctic Peninsula, including King George Island where Marian Cove is located. Consequently, these phenomena are expected to induce changes in the water column light properties, which in turn will affect phytoplankton communities. To comprehend the effects of glacial retreat on the marine ecosystem in Marian Cove, we investigated on phytoplankton biomass (chlorophyll-a, chl-a) and various environment parameters in this area in December 2021 and January 2022. The average temperature at the euphotic depth in January 2022 (1.41 ± 0.13 ℃) was higher than that in December 2021 (0.87 ± 0.17 ℃). Contrastingly, the average salinity was lower in January 2022 (33.9 ± 0.10 psu) than in December 2021 (34.1 ± 0.12 psu). Major nutrients, including dissolved inorganic nitrogen, phosphate, and silicate, were sufficiently high, and thus, did not act as limiting factors for phytoplankton biomass. In December 2021 and January 2022, the mean chl-a concentrations were 1.03 ± 0.64 and 0.66 ± 0.15㎍ L^-1, respectively. The mean concentration of suspended particulate matter (SPM) was 24.9 ± 3.54 mgL^-1 during the study period, with elevated values observed in the vicinity of the inner glacier. However, relative lower chl-a concentrations were observed near the inner glacier, possibly due to high SPM load from the glacier, resulting in reduced light attenuation by SPM shading. Furthermore, the proportion of nanophytoplankton exceeded 70% in the inner cove, contributing to elevated mean fractions of nanophytoplankton in the glacier retreat marine ecosystem. Overall, our study indicated that freshwater and SPM inputs from glacial meltwater may possibly act as main factors controlling the dynamics of phytoplankton communities in glacier retreat areas. The findings may also serve as fundamental data for better understanding the carbon cycle in Marian Cove.

• Exercise Science
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• v.21 no.2
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• pp.183-190
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• 2012

This study is to evaluate the availability of cardiorespiratory fitness measurement by 20 m shuttle run test based upon energy contribution rates of elite athletes in different sports type. Sixty-seven elite athletes attending K national university participated in this study. They were divided by three groups based upon sports type, composed of Anaerobic Group (sprint, jumps, weightlifting, throw; n=35), Aerobic Group (medium-long distance; n=9), and Combat Sport Group (judo; n=23). 20 m shuttle run test was conducted by Leger et al.(1982) method and calculating acceleration using measured shuttle run repetitions was conducted by Brewer et al.(1988) method. To test the usefulness of VO₂max, graded exercise treadmill test was conducted and standing long jump and 50 m run were measured as power fitness factors. Z-jump was used for measuring power, agility, and muscular endurance. Standing long jump and 50 m run of Anaerobic Group (AnG) was significantly higher than that of Aerobic Group (AeG) and Combat Sport Group (CG) (p<0.05). However, Z-jump of CG was significantly higher than that of AnG and AeG(p<.05). There was a higher correlation of 20 m shuttle run test and VO₂max in AnG(r= 0.577, p<.0001) and CG(r= 0.760, p<.0001). Otherwise, there was a low correlation of 20 m shuttle run test and VO₂max in AeG. There was no significant group difference to test the availability of 20 m shuttle run test and there was a reduced error when converting 20 m shuttle run results into VO₂max. This study examined the usefulness of 20 m shuttle run test by converting 20 m shuttle run repetition results into VO₂max calculation, which showed reduced error. Therefore, this study confirmed that it would be needed to convert 20 m shuttle run results into VO₂max for universal and practical use in the field without dividing sports type.

• Journal of Practical Agriculture & Fisheries Research
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• v.15 no.1
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• pp.95-105
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• 2013

This study has been conducted to investigate the effect of Urea and K₂SO₄ treatment at stone hardening stage and 20 days before harvest on soil chemical properties, mineral nutrient concentration and quality of 'Mibaekdo' fruit peach. K concentration after Urea and K₂SO₄ treatment in soil was increased significantly by Urea 162g+K₂SO₄ 188g/tree(standard amount) treatment at stone hardening stage, K₂SO₄ 1.0% tree-spray, Urea 81g+K₂SO₄ 94g/tree(half amount), Urea 162g+K₂SO₄ 188g/tree and Urea 324g+K₂SO₄ 376g/tree(double amount) soil treatment before harvest 20 days compared to control. T-N, K and Ca concentration in leaf was increased significantly by all treatment. but Na concentration in leaf was increased by Urea 0.5% and K₂SO₄ 1.0% tree-spray treatment before harvest 20 days. T-N concentration in fruit skin was increased significantly by standard amount soil treatment, which decreased by K₂SO₄ 1.0% tree-spray and half amount soil treatment. T-N, K and Ca concentration in fruit flesh(1~10mm depth flesh from peel) were increased markedly by all treatment excepted Urea 0.5% tree-spray. The leaf weight at harvest was increased markedly by Urea 0.5% tree-spray, standard amount and double amount treatment before harvest 20 days. Fruit weight was increased significantly by standard amount compared to all treatment. Red fruit skin(Hunter a value) progress was effective by K₂SO₄ tree-spray, half amount and double amount treatment before harvest 20 days. Fruit SSC was increased significantly by Urea 0.5% and K₂SO₄ tree-spray before harvest 20 days, standard amount treatment at stone hardening stage compared to control.