• Korean Journal of Soil Science and Fertilizer
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• v.42 no.1
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• pp.58-64
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• 2009

The objectives of this study were to investigate the aggregate fragmentation in wet-sieving and to evaluate the relationship between the aggregate fragmentation fractal dimension and macro-porosity of upland soils, using three different textural types of soils including Gopyeng series (Fine, Typic Hapludalfs), Gyuam series (Fine silty over coarse silty, Fluvaquentic Eutrudepts), and Jungdong series (Coarse loamy, Typic Udifluvents) located in Gyeonggi province. Undisturbed soil samples with five replicates were seasonally sampled and used for measuring water stable aggregate, macropores, and physico-chemical properties of soils. The aggregate stability in wet-sieving was digitalized as three types of fragmentation fractal dimension ($D_f$), geometric mean diameter (GMD), and mean weight diameter (MWD). $D_f$ had higher correlation with GMD than with MWD. Seasonal aggregate stability showed the highest values in summer, and decreased in the order of spring and autumn. The macroporosity had higher in topsoil, in autumn, and in ridge, than in plow pan layer, in summer, and in row, respectively. The relationship between $D_f$ and macroporosity, especially more than 99 m, showed high correlation only in soils with $D_f$ less than 3.1, which means more aggregated soils compared to soils with $D_f$ more than 3.1. Besides, in the soils with the fractal dimension less than 3.1, the power function relation between saturated hydraulic conductivity and macroporosity more than 99 m had relatively high determinant coefficient, and vice versa. Therefore, it could be thought that fragmentation fractal dimension is available for confirming macroporosity induced from aggregation.

• Journal of Bio-Environment Control
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• v.30 no.4
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• pp.304-311
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• 2021

This Experiment was conducted to determine the effects of light shield materials when melon grown inside a plastic greenhouse in summer season. The average temperatures were 36.6℃, 34.5℃ and 34.0℃ respectively for the control(non-shield), coating agent, and the white net. The light transmittances were 69% and 75%, respectively inside the greenhouse treated with the coating agent and white net immediately after applicants, compared with that inside the control greenhouse. At the 40 and 80 days after treatment, the light transmittances for the coating agent were 92% and 98%, respectively, indicating it was slowly decomposed and removed, but there was no change in the transmittance for the white net. While the leaf number did not differ among the treatments, the plant height was higher in the white net and shading agent than in control. The weight of the leaves, fresh-weight and dry-weight were no different from that of shading, but it became heavier in the later stages. The marketable fruit yield was increased by 6% for white nets and 5% for the coating agent compared to control, there was no statistical significance. Therefore, coating agent is considered as an effective method to lower temperature during high temperature period, but it is preferable to use it in consideration of cultivation period, because the coating agent is gradually removed.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.3
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• pp.253-259
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• 2021

Plastic wastes generated from household waste are separated by mixed discharge with foreign substances, and recycling is relatively low. In this study, the effect of the ratio and content of mixed plastic waste coarse aggregate(MPWCA)s and mixed plastic waste fine aggregate(MPWFA)s filled with blast furnace slag fine powder on the slump and compressive strength of concrete was evaluated experimentally. The MPWCAs were found to have a similar fineness modulus, but have a single particle size distribution with a smaller particle size compared to coarse aggregates. However, the MPWFAs were found to have a single particle size distribution with a larger fineness modulus and particle size compared to fine aggregates. Meanwhile, the effect of improving the density and filling pores by the blast furnace slag fine power was found to be greater in the MPWFA compared to the MPWCA. As the amount of the mixed plastic waste aggregate(MPWA)s increased, the slump and compressive strength of concrete decreased. In particular, the lower the slump and compressive strength of concrete was found to decrease the greater the amount of MPWFA than MPWCA when the amount of MPWA was the same. This is because of the entrapped air and voids formed under the angular- and ROD-shaped aggregates among the MPWFAs. On the other hand, the addition of the admixture and the increase in the unit amount of cement were found to be effective in improving the compressive strength of the concrete with MPWAs.

• Journal of Korean Neurosurgical Society
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• v.64 no.3
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• pp.437-446
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• 2021

Objective : To investigate the radiographic characteristics of the uppermost instrumented vertebrae (UIV) and UIV+1 compression fractures that are predictive of revision surgery following long-segment spinal fixation. Methods : A total 27 patients who presented newly developed compression fracture at UIV, UIV+1 after long segment spinal fixation (minimum 5 vertebral bodies, lowest instrumented vertebra of L5 or distal) were reviewed retrospectively. Patients were divided into two groups according to following management : revisional surgery (group A, n=13) and conservative care (group B, n=14). Pre- and postoperative images, and images taken shortly before and after the occurrence of fracture were evaluated for radiologic characteristics Results : Despite similar degrees of surgical correction of deformity, the fate of the two groups with proximal junctional compression fractures differed. Immediately after the fracture, the decrement of adjacent disc height in group A (32.3±7.6 mm to 23.7±8.4 mm, Δ=8.5±6.9 mm) was greater than group B (31.0±13.9 mm to 30.1±15.5 mm, Δ=0.9±2.9 mm, p=0.003). Pre-operative magnetic resonance imaging indicated that group A patients have a higher grade of disc degeneration adjacent to fractured vertebrae compared to group B (modified Pfirrmann grade, group A : 6.10±0.99, group B : 4.08±0.90, p=0.004). Binary logistic regression analysis indicated that decrement of disc height was the only associated risk factor for future revision surgery (odds ratio, 1.891; 95% confidence interval, 1.121-3.190; p=0.017). Conclusion : Proximal junctional vertebral compression fractures with greater early-stage decrement of adjacent disc height were associated with increased risk of future neurological deterioration and necessity of revision. The condition of adjacent disc degeneration should be considered regarding severity and revision rate of proximal junctional kyphosis/proximal junction failures.

• The Korean journal of internal medicine
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• v.33 no.6
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• pp.1111-1118
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• 2018

Background/Aims: Chest pain is an essential symptom in the diagnosis of acute coronary syndrome (ACS). One-third of patients with ACS present atypically, which can influence their receiving timely lifesaving therapy. Methods: A total of 617 NSTEMI patients from the Korea Acute MI Registry (KAMIR) and the Korea Working Group on MI (KorMI) databases were analyzed. The study population was divided into two groups by symptoms at presentation (typical symptoms group, 128; atypical symptoms groups, 128). Results: In this study population, 23% of patients presented without chest pain. After propensity score matching, the contact-to-device time ($2,618{\pm}381minutes$ vs. $1,739{\pm}241minutes$, p = 0.050), the symptoms-to-balloon time ($3,426{\pm}389minutes$ vs. $2,366{\pm}255minutes$, p = 0.024), and the door-to-balloon time ($2,339{\pm}380minutes$ vs. $1,544{\pm}244minutes$, p = 0.002) were significantly higher in the patients with atypical symptoms than in those with typical symptoms, respectively. Atypical symptoms were an independent predictor for 1-year mortality (hazard ratio, 2.820; 95% confidence interval, 1.058 to 7.515; p = 0.038). The Kaplan-Meier estimates showed higher risk for 12-month mortality in patients with atypical symptoms (p = 0.048) and no significant difference for 12-month major adverse cardiac events (p = 0.487). Conclusions: Acute myocardial infarction patients with atypical symptoms were not rare in clinical practice and showed a high risk of delayed reperfusion therapy. After imbalance between the groups was minimized by use of propensity score matching, patients who presented atypically had a high mortality rate.

• International Area Studies Review
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• v.22 no.4
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• pp.99-121
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• 2018

This study investigated the factors influencing the knowledge acquisition of Thai local partners from advanced foreign partners through international joint ventures(IJVs). For this purpose, this study initially identified three dimensions of characteristics in the context of IJVs that would influence local partners' knowledge acquisition - a local partners' own characteristic (absorptive capacity), a relationship characteristic with IJVs (proximity to the equal equity ownership), and a relationship characteristic with foreign partners (trust), and examined their effects on local partners' knowledge acquisition. The study further investigated the moderating effects of the tacitness of knowledge on the relationships between those characteristics and knowledge acquisition. Based on the data collected from Thai IJV local partners, results revealed that a local partners' own characteristic, absorptive capacity, and a relationship characteristic with IJVs, proximity to the equal equity ownership, had a strong positive effect on local partners' knowledge acquisition. Results further showed that the tacitness of knowledge strengthened the relationships between absorptive capacity and knowledge acquisition and between trust and knowledge acquisition, but not the relationship between proximity to the equal equity ownership and knowledge acquisition.

• Korean Journal of Breeding Science
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• v.42 no.4
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• pp.413-418
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• 2010

A total of 424 plants was regenerated from the seed-culture of a rice cultivar, 'Ilpum'. The regenerated plants were grown in a greenhouse. The 297 plants with high fertility were selected among 424 plants. The harvested seeds from each plant were planted to each line at experiment field in 2008 and 2009. The each line was evaluated for the agronomic and morphological traits, also. The 64 lines (21.5%) showed significant differences in agronomic and morphological traits from donor cultivar 'Ilpum' among 297 lines. The heading date different from donor cultivar 'Ilpum' showed highest frequency in 297 lines, and accounts for 9.1% (29 lines). The phenotype of opaque endosperm and rolling leaf account for 1.7% and 1.3% in 297 lines, respectively. The genetic segregation was observed in dwarf/semi-dwarf, rolling leaf and opaque endosperm at $S_1$ generation, but not in $S_2$ generation. These results suggest that the mutant derived from a tissue-culture will be one of the promising genetic resources, due to its wide variation and high frequency of mutation, comparatively.

• Korean Journal of Breeding Science
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• v.42 no.1
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• pp.56-60
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• 2010

This study was carried out to develop of macro-protocol and the biosafety guide Golden Rice, modified vitamin A at large scale GMO field. Commercialization of genetically modified (GM) plants will be required the assessment of risks associated with the release of GM plants that should include a detailed risk assessment of their impacts in the environment and human health. Prior to GM plant release, applicants should provide the information on GM crops for approval. A total of $4,700m^2$ GM field, each of Golden Rice and 'Nakdong' were used for further analysis on agronomic traits and pathogenesis. Generally plant growth and panicle number in the transgenic lines were lower than in the wild type under field condition. The major agronomic traits such as plant growth, grain quality in Golden Rice were similar than in 'Nakdong'. The yield difference was due to reduced ripened rate and the 1,000 grain weight. The grain shape was similar donor plant, however, color of brown rice was different from segregation. Also the difference of pathogenesis reaction was not significant in the leaf blast and sheath blight between Golden Rice and 'Nakdong'. These results provided the agronomic data and pathogenesis for risk assessment analysis of Golden Rice and suggested that the macro-protocol could be useful to detect GM plants.

• Korean Journal of Breeding Science
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• v.43 no.5
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• pp.470-478
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• 2011

This study was carried out to find major factors affecting the color of wheat flour and noodles and develop simple analysis method for the breeding of wheat cultivars suitable for producing flour and noodles with bright color which are preferred by consumers. Customers who buy white noodle or flour prefer bright-colored food to dark-colored products. We evaluated grains of 25 Korean wheat cultivars for chemical composition, grain characteristics, and color change of noodle dough sheets during storage. Polyphenol oxidase (PPO) has been connected to discoloration of white salted noodles and other wheat end products. The grain PPO activity was reduced as the 1,000 grain weight, grain ash content, and protein content decreased. The grain PPO activity was positively correlated with the total polyphenol content ($r=0.609^{**}$) and iron content ($r=0.655^{**}$). Lightness, protein, polyphenol and Fe content of flour were positively correlated with PPO activity of grain. Cultivars with higher grain PPO activity showed darker noodles and were more easily discolored during the storage (from 2 hr to 48 hr). Thus, PPO activity can be used as a selection index in a breeding program for wheat cultivars of bright-colored flour.

• Korean Journal of Breeding Science
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• v.40 no.2
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• pp.164-167
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• 2008

A rose cultivar "Haedoji" developed at the Jeollanamdo Agricultural Research and Extention Services (JARES) is a standard type with deep Red flower. From 2000, two cultivars 'Vital' and 'Cardinal' were examined for horticultural characteristics and were included in cross-combination in 2003. Cultivar 'Vital', a vigorous standard type, first preference with red flower, was used as a mother plant and cultivar 'Cardinal', a red flower standard type with light color, was used as a pollen-donor plant. seventeen six breeding lines were selected in 2004 based on flower shape, flower color and abundance of petal numbers on the first selection. two breeding lines were selected in 2004 based on powderly mildew and vigor on the second selection. For three years, from 2005 till 2007, one breeding lines were selected and examined for their productivity, and then cultivar "Haedoji" was developed because of distinctive characters such as light red color flower, upright stem, long vase-life and Resistance to the Powderly Mildew. A standard type with intermediate sized flower, cultivar "Haedoji" shows in average 9.2 cm flower diameter, 62.0 cm flower stem length, and 9.5 days vase-life. The average productivity for three years was $167.3stems{\cdot}m^{-2}$ per year and increased 2% compare to cultivar 'Tiamo' with $163.9stems{\cdot}m^{-2}$ per year.