• KOREAN JOURNAL OF CROP SCIENCE
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• v.31 no.3
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• pp.260-269
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• 1986

This experiment was conducted to investigate the effect of mulching materials on the emergence rate, root dry weight and grain weight of sesame using variety Poong Nyun Ggae and also their effects on physical properties of soil, evapotranspiration and weed growth on the respective plots were studied. The effect of soil water holding capacity at mulching with polyethylene film and straw increased 5.4%, 2.8% to non-mulched plot respectively. The maximum soil temperature was raised up to 4$^{\circ}C$ by applying clear film and was dropped down to 7$^{\circ}C$ by straw. The minimum soil temperature was raised up to 2$^{\circ}C$ by clear film and was dropped down to 3$^{\circ}C$ by straw. In the early stage, the soil physical properties of clear film mulching were better than those of non mulching, and so was in emergence rate. In the late stage, soil strength was high at non mulching, and soil porosity, soil aeration and water infiltration rate were high at film and straw mulchings. Total root dry weight was great at clear film mulching, and root dry weight was concentrated mainly in the upper 10 cm of soil profile. The amount of weeds collected was the least at black film mulching. There were of little difference in evapotranspiration among treatments. The grain yield of sesame was increased to 57% by polyethylene film and 25% by straw mulching.

• The Journal of the Convergence on Culture Technology
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• v.9 no.1
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• pp.539-544
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• 2023

The subject of this study is the Maae Buddha statue in granodiorite of the Mesozoic Cretaceous period, which is concerned about stability as a standing stone cultural property located in ◯◯-dong, Gyeongsangbuk-do. For stability analysis, three-dimensional face mapping, geological properties of joints, three-dimensional scanning, ultrasonic velocity, polarization microscopy, electron microscopy analysis and XRD analysis were performed. In addition, the safety factor of the Maaebul was calculated by analyzing the damage status investigation, stereographic projection analysis, rock classification, and limit equilibrium analysis. The types and scales of damage and possible collapse by section depend on the degree of weathering of the rock and the orientation and characteristics of the joints, but wedge-failure and toppling-failure are expected to be small-scale. The safety factor of Maaebul in dry and wet conditions is less than 1.2, so stability is concerned. The types of damage were mainly observed, such as exfoliation, cracking, granular decomposition, and vegetation growth. The Maaebul rock is granodiorite, and the surface discoloration materials are K, Fe, and Mg. The 4 sets of joints are developed, J1 is tensile joint and the others are shear joint. The uniaxial compressive strength estimated by ultrasonic exploration is 514kgf/cm2, which corresponds to most soft rocks and some weathered rocks. Rock classification(RMR) is estimated to be grade 5, very poor rock mass. These technique along with the existing methods of safety diagnosis of cultural properties are expected to be a reasonable tool for objective interpretation and stability review of stone cultural properties.

• Korean Journal of Environmental Biology
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• v.40 no.3
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• pp.341-351
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• 2022

Among various environmental stresses, humid stress lacks mechanisms and biochemical understanding compared to drought, low temperature, and high salt stresses. The aim of this study was to investigate enzyme activity of field crops under humidity stress. Results of this study could be used as basic data for understanding humidity stress and early diagnosis. Growth and enzyme activities of sesame, perilla, red beans, sorghum, and beans as major field crops in Korea when flooded were investigated. It was confirmed that growths of both shoots and roots were retarded. In plants, anaerobic fermentation occurred due to flooding stress, which increased the activity of alcohol dehydrogenase (ADH) compared to the control group. Increases of reactive oxygen species (ROS) were also observed. All flooded plants showed increased peroxidase (POD) activity and lipid peroxidation. Their dyeing strength was darker than that of the control group, even in 3,3'-diaminobenzidine (DAB) staining. Since enzyme activity changes in plants appear relatively faster than changes in phenotype at the ground level, they could be used as biomarkers for early diagnosis of humidity stress in crops.

• Journal of the Korean Society of International Agriculture
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• v.31 no.2
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• pp.178-182
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• 2019

'Muha' is a new strawberry (Fragaria x ananassa Duch.) cultivar, which was released by the Highland Agriculture Research Institute in 2015. The 'Muha' cultivar originated from a cross between 'Maehyang' and 'Selva' that showed excellent ever-bearing characteristics, including continuous flowering habit and high soluble-solid content under long-day and high temperature conditions in 2010. This cultivar was initially named 'Saebong No. 7' after examining its characteristics and productivity in summer culture from 2011 to 2014. After regional adaptability tests in 2015, 'Muha' was selected from Saebong No. 7 as an elite cultivar. The general characteristics of 'Muha' include semispreading type, elliptical leaf, and strength vigor in growth. The fruits are conical in shape, red in color. 'Muha' plants have 18.7 flower clusters, 8.7 more than 'Flamenco' plants. The fruit hardness of 'Muha' and Flamenco' was about the same. The number of fruits of 'Muha' was 37.2, which was 20 higher than that of 'Flamenco'. The marketable yield was 23,981 kg·ha^-1, 159% higher than 'Flamenco'. 'Muha' is suitable for north and highland area of the Southeast Asia as a high hardness and yield cultivar, because it showed continuous flowering habit under long-day and high temperature conditions.

• Journal of The Korean Association For Science Education
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• v.27 no.9
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• pp.907-918
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• 2007

This study was conducted to explore key factors of expertise development of talented scientists who achieved outstanding research performance according to the stages of expertise development and dimensions of individual-domain-field. To fulfill the research purpose, 31 domestic scientists who were awarded major prizes in the field of science were interviewed in-depth from March to September, 2007. Stages of expertise development were analyzed in light of Csikszentmihalyi's IDFI (individual-domain-field interaction) model. Self-directed learning, multiple interests and finding strength, academic and liberal home environment, and meaningful encounter were major factors affecting expertise development in the exploration stage. In the beginner stage, independence, basic knowledge on major, and thirst for knowledge at university affected expertise development. Task commitment, finding flow, finding their field of interest and lifelong research topic, and mentor in formal education were the affecting factors in the competent stage. Finally, placing priority, communication skills, pioneering new domain, expansion of the domain, and evaluation and support system affected talented scientists' expertise development in the leading stage. The meaning of major patterns of expertise development were analyzed and described. Based on these analyses, educational implications for nurturing scientists were suggested.

• Clean Technology
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• v.30 no.2
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• pp.145-156
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• 2024

Carbon has a large specific area and excellent chemical stability, so research on its use as a catalyst support is actively conducted. When using carbon as a support, the pretreatment process is essential. Through pretreatment of carbon, the growth of metal nanoparticles can be controlled and the bonding strength between the support and metal particles can be improved. In this study, carbon was pretreated for surface modification and 5 wt% Pd/C catalysts were synthesized using it as a support. Catalytic activity was evaluated through phenol hydrogenation. To compare with nitric acid, which is commonly used in carbon pretreatment, carbon pretreatment was performed using organic acid. Pd/C treated with gluconic acid showed the highest activity, with 94.93% phenol conversion and 92.76% cyclohexanone selectivity. Therefore, it is expected that pretreatment of the carbon support using organic acid will not only overcome the disadvantages of inorganic acid treatment but also improve catalyst performance.

• Convergence Security Journal
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• v.24 no.2
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• pp.181-188
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• 2024

Amid global geopolitical crises that are heightening tensions worldwide, the importance of national security is being reevaluated. Consequently, South Korea is gaining attention in the global defense market due to its superior technology, competitive pricing, and rapid delivery capabilities. The increasing international demand for defense materials offers opportunities for the development of the domestic defense industry and has the potential to lead to long-term defense strategies and an expansion of exports. In particular, the development of future advanced weapons systems and the expansion of defense exports are likely to be possible through a deep understanding of the international political and economic situation and proactive defense diplomacy. This study analyzes the impact of current global geopolitical crises on Korea's defense industry and presents effective strategies based on these findings, including innovative improvements to defense acquisition systems and the discovery of overseas defense cooperation partners to strengthen defense exports. This strategic approach aims to balance domestic consumption with exports, enhance military strength, and improve the country's standing in the international community. Therefore, efforts are needed to ensure the sustainable growth of the defense industry, enabling South Korea to achieve economies of scale and play a pivotal role in the global defense industry.

• Journal of the Korea institute for structural maintenance and inspection
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• v.11 no.2
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• pp.69-76
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• 2007

As amount of waste matter rapidly increases with fast growth of cities and industry, how to dispose them has arisen as an important problem. Current policy of the government on disposal of waste is repressing generation of waste itself and in case of already generated waste, resource cycle waste management system that recycles waste after proper environmental process is getting established. Therefore recycling of waste and industrial by-products is rising hugely. One of largely wasted matters is waste gypsum, which was categorized as designated waste but changed to general since 1994. Due to disposal cost and lack of impurities removal technology, recycling of it was quite low. However, as impurities removal technology using semi-dried desulfurization process is developed lately, study on recycling of waste gypsum is going on lively. This study examines possibility of utilizing waste gypsum as alternative for concrete cement and analyzed attributes of waste gypsum before and after ball mill process to find out proper alternation ratio, and conducted strength and property tests on concrete subject whose percentage of cement use is substituted with 0, 5.0, 7.5, 10.0 and 12.5% of waste gypsum.

• Journal of Korean Society of Forest Science
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• v.102 no.3
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• pp.315-322
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• 2013

This study was carried out to establish a management program and soil restoration plan through analysis of soil properties and visitor questionnaires in Songrim in Hadong, Korea. Soil bulk density in Songrim was slightly higher in the closed-woodlands ($1.31g/cm^3$) than in the open-woodlands ($1.39g/cm^3$). Soil bulk density in the closed-woodlands was higher in walking trails ($1.74g/cm^3$) than in forest areas ($1.39g/cm^3$), while the rates of pore space were lower in walking trails (42.6%) than in forest areas (50.5%). The soil porosity were lower in the closed-woodlands (34.6%) than in the open-woodlands (42.6%). Soil strength in surface soil was slightly lower in the open-woodlands ($8.5kgf/cm^2$) than in the closed-woodlands ($10.5kgf/cm^2$). The content of organic matter, total nitrogen and exchangeable cations of the woodlands was low compared with the optimum nutrient content for tree growth in Korea forest soil. According to the survey, the objective of visiting in Songrim was to enjoy recreation and landscape views. To conserve pine forest ecosystems in Songrim, the respondents said that it needs to the implement of closed-woodland periods, the establishment of smoking free zone, and the prohibition of garbage throwing and alcohol including disciplinary rules and education. Also the respondents said that pine forest ecosystem in Songrim is relatively sound, but the woodlands require the intensive management to the ecosystem and the introduction of native understory vegetation, such as grasses under pine forest ecosystem. It is recommended to designate the rest-year forest for a proper period in all woodlands to restore the Songrim soil rather than the alternation application between the rest-year for three years or non-rest-year trails, and to open partially the walking trails across the woodlands after the period. In addition, the forest within the woodland is need to designate a long-term rest-year.

• Korean Journal of Weed Science
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• v.32 no.2
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• pp.85-97
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• 2012

To investigate the usefulness of freshwater alga Water-net (Hydrodictyon reticulatum, HR) as resources for production of fermentable sugars, the easiness of enzymatic saccharification was evaluated at first. When 6 plant materials (HR, Spirulina, Chlorella, Scenedesmus, Cladophora, Corn stover) were enzymatically hydrolyzed with 2% solid loading at the same condition, HR showed the highest ratio of saccharification based on glucose production. No milled HR was also completely saccharified at the amounts of optimal enzyme mixture. Glucose yield was not changed though the citrate buffer strength for saccharification was decreased from 0.1 M to 0.1 mM. Only about 10% yield reduction was observed compared to that of $120^{\circ}C$ treatment when HR was enzymatically hydrolyzed at room temperature. The saccharification was normally occurred at $37^{\circ}C$ and pH 6.5 which is general growth condition of fermentable microrganisms, suggesting that HR have a biomass characteristics applicable for the simultaneous saccharification and fermentation. The saccharification was occurred by more than 70~80% of one of the best condition although the supplied enzyme amounts was reduced to 1/10 volume. And the glucose yield by enzymatic hydrolysis was not decreased by 10% HR solid loading and began to decrease at more than 15% solid contents. Above these results show that HR is an interesting algal biomass which is relatively easy to be saccharified by hydrolyzing enzymes. In addition, HR is a flilamentous alga and very easy to be collected. Therefore, HR seems to be an useful and valuable resources in the economical production of fermentable sugars for manufacture of bio-chemical products.