• Journal of the Korean Wood Science and Technology
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• v.47 no.3
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• pp.360-370
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• 2019

Woody crops cultivated in short-rotation coppices are attractive sources of lignocellulosic materials for bioethanol production, since they are some of the most abundant renewable resources. In this study, we evaluated the effects of the growth period on bioethanol production using short-rotation woody crops (Populus nigra ${\times}$ Populus maxiwiczii, Populus euramericana, Populus alba ${\times}$ Populus glandulosa, and Salix alba). The carbohydrate contents of 3-year-old and 12-year-old short-rotation woody crop branches were 62.1-68.5% and 64.0-67.1%, respectively. The chemical compositions of 3-year-old and 12-year-old short-rotation woody crop branches did not vary significantly depending upon the growth period. However, the 3-year-old short-rotation woody crop branches (glucose conversion: 26-40%) were hydrolyzed more easily than their 12-year-old counterparts (glucose conversion: 19-24%). Furthermore, following the fermentation of enzymatic hydrolysates from the crop branch samples (by Saccharomyces cerevisiae KCTC 7296) to ethanol, the ethanol concentration of short rotation coppice woody crops was found to be higher in the 3-year-old branch samples (~ 0.18 g/g dry matter) than in the 12-year-old branch samples (~ 0.14 g/g dry matter). These results suggest that immature wood (3-year-old branches) from short-rotation woody crops could be a promising feedstock for bioethanol production.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.4
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• pp.304-311
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• 1993

To find out suitable crops and their rotation years with rice for paddy-upland rotation, continuous rice cropping and rice with 1, 2 and 3 years cropping of upland crops(soybean, maize and job's tears) were tested for four years from 1989 to 1992. Rice yield, when averaged over rotation years for each crop, was increased ranging from 7% to 12% when compared with that of continuous rice cropping. With every crop, rice yield of 2 year upland rotation was higher than that of 1 year upland rotation, but rice quality seemed to deteriorate in paddy-upland rotation. When considering yields of the upland crops, 1 year rotation was the best condition for soybean and job's tears, with 3 years rotation being the best for maize. In paddy-upland rotation, number of weed species and its occurrence rates were reduced in paddy and upland condition and the reduction rates in paddy condition were higher than those in upland condition. Physical properties of soil were improved in paddy-upland rotation and airphase seemed to increase with increasing upland period.

• Korean Journal of Child Studies
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• v.20 no.3
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• pp.293-306
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• 1999

This study investigated children's spatial skills and short term memory ability based on their practice with computer games. The 40 four-year-old and 40 six-year-old subjects were divided by experimental and control groups. Spatial skills of children were assessed by visual speed, mental rotation, and spatial visualization tasks. Short term memory was measured with a digit span task. Results showed that computer game practice enhanced children's memory ability and spatial skills. Even 4-year-olds performed better on mental rotation and spatial visualization tasks after practice. The treatment effect was significant for visual speed of 6-year-olds, short term memory ability and mental rotation of 4-year-olds, and spatial visualization of both 4- and 6-year-olds.

• Korean Journal of Soil Science and Fertilizer
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• v.26 no.3
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• pp.181-188
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• 1993

The effects of paddy-upland rotation and cropping system on the mineralization of soil organic nitrigen, on the change of organic matter and available phosphorus content in the soil, and on the rice yield and nutrients absorption were studied in Seokcheon fine-sandy loam soil. 1. In the incubation test mineralzed soil nitrogen and the nitrogen extracted by pH 7 phosphate buffer solutions were higher in the soils from every and two year rotation systems than continuous rice cultivation. In terms of cropping system potato-chiness cabbage-rice increased them more than soybean-rice system. 2. The change of soil organic matter and available phosphorus contents were not much in continuous rice cultivation, while in rotation system they decreased as the paddy-upland rotation frequency decreased. In terms of cropping system they decresed more in potato-Chinese cabbage-rice system compared with soybean-rice systems. 3. The rice yield was higher in the paddy-upland rotation system than that of continuous rice cultivation. However, the effects were decreased gradually every year, as shown by 26~20, 17~5, and 5~4% yield increase for first, second, and third year, respectively, in potato-Chinese cabbage-rice and soybean-rice system compared with continuous rice cultivation. 4. All the absorbed nutrient contents increased in every and two year rotation system compared with continuous rice cultivation. In terms of cropping system potato-Chiness cabbage-rice system increased them more compared with soybean-rice system.

• Korean Journal of Medicinal Crop Science
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• v.24 no.4
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• pp.294-302
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• 2016

Background: Crop rotation plays an important role in improving soil chemical properties, minimizing the presence of disease pathogens, and assists in neutralizing autotoxic effects associated with allelochemicals. Methods and Results: Five rotation crops of sudan grass, soybean, peanut, sweet potato, and perilla were cultivated for one year with an aim to reduce yield losses caused by repeated cropping of ginseng. In 2-year-old ginseng grown in the same soil as a previous ginseng crop, stem length and leaf area were reduced by 30%, and root weight per plant was reduced by 56%. Crop rotation resulted in a significant decrease in electrical conductivity, $NO_3$, and $P_2O_5$ content of the soil, whereas organic matter, Ca, Mg, Fe, Cu, and Zn content remained-unchanged. Soil K content was increased following crop rotation with sudan grass and peanut only. Rotation with all alternate crops increased subsequent ginseng aerial plant biomass, whereas root weight per plant significantly increased following crop rotation with perilla only. A significant positive correlation was observed between root rot ration and soil K content, and a significant negative correlation was observed between ginseng root yield and the abundance of actinomycetes. Crop rotation affected the soil microbial community by increasing gram negative microbes, the ratio of aerobic microbes, and total microbial biomass whereas decreases were observed in actinomycetes and the ration of saturated fatty acids. Conclusions: In soil exhibiting crop failure following replanting, crop rotation for one year promoted both soil microbial activity and subsequent ginseng aerial plant biomass, but did not ameliorate the occurrence of root rot disease.

• Journal of Korean Society of Forest Science
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• v.105 no.1
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• pp.103-107
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• 2016

This study aims to select the most appropriate poplar clones for planting on short rotation coppice poplar plantations in a riparian area. The research investigated biomass production, nitrogen and carbon absorption with 2-year-old poplar (Populus spp.) clones including P. euramericana clone Eco28, P. deltoides hybrid clone 97-18, and P. alba ${\times}$ P. glandulosa hybrid clone 72-30. The average number of stems per stump was five and P. euramericana clone Eco28 had the greatest average number of live stems per stump with 5.9. The average stem diameter was 23.2 mm, and P. deltoides hybrid clone 97-18 achieved the largest average diameter with 25.4 mm. The average annual above-ground biomass production of Populus deltoides hybrid clone 97-18 was 16.1 ton/ha/year, followed by P. alba ${\times}$ P. glandulosa hybrid clone 72-30 and P. euramericana clone Eco28, 12.3 and 5.4 ton/ha/year, respectively. The average annual nitrogen uptake of poplar clones was 46.5 kg/ha/year. P. alba ${\times}$ P. glandulosa hybrid clone 72-30 had the highest average, 63.1 kg/ha/year. The average of annual carbon absorption was estimated 5.3 ton/ha/year and Populus deltoides hybrid clone 97-18 showed the best results with 7.7 ton/ha/year. Based on the results given above, P. deltoides hybrid aspen clone 97-18 is considered as the most suitable poplar clones for wood biomass production on riparian areas.

• Applied Biological Chemistry
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• v.40 no.5
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• pp.438-441
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• 1997

The relatedness of naturalized Bradyhizobium japonitum populations with soil physico-chemical characteristics as affected by paddy rice-upland soybean rotation cropping with conventional and none fertilization in Chilgog clay loam soils were determined as follows. The populations of B. japonicum in soils were increased from about $10^1$ in continuous paddy upto $10^1cells/g.soil$ only in one-year rotation of upland use with soybean cropping. Compared to the densities in plots of conventional fertilization, those in none fertilization were high ranging from 1.9 to 10 fold in 2-year upland use rotation and both in 3-year upland use rotation and 4-year upland use, respectively. The populations were positively correlated with soil organic matter $contents(r=0.83^*),\;Ca/K(r=0.74^*),\;and(Ca+Mg)/K(r=0.72^*)$ and were negatively correlated with soil $hardness(r=-0.73^*)$. And the soil populations increased by paddy-upland rotation resulted in superior symbiotic potentials to those in continuous paddy use in terms of nodule mass, nitrogenase activity, and soy-bean shoot dry weight.

• Archives of Plastic Surgery
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• v.39 no.3
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• pp.244-248
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• 2012

Many types of upper lip reconstruction have been introduced to treat defects after a tumor excision or trauma. The authors treated two cases of upper lip defects. A 35-year-old woman presented with a squamous cell carcinoma of the left upper lip that had invaded the corner of the mouth. After resecting the tumor, the defect was $3.7{\times}3.5cm$ in size. A 52-year-old woman presented with a dog bite of the right upper lip. The defect measured $4.0{\times}2.2cm$ in size. The two cases were reconstructed by combined rotation and advancement of a cheek flap. This technique produced a good functional outcome that allowed for oral competence and created an opening of adequate size. A combination of rotation and an advancement flap can be used to treat upper lip defects in a single-stage procedure. This approach produces a good functional and cosmetic outcome.

• Journal of Korean Society of Forest Science
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• v.55 no.1
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• pp.30-36
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• 1982

Wood biomass production at 1-year, 2-year, and 3-year rotations on both low and upper hills at 2m 2m spacing (25,000 trees/ha) was studied for a six-year period with following 12 species; Lespedeza cyrtobotrya Amorpha fruticosa. Robinia pseudoacacia, Acer saccharinum, Platanus orientalis Populus alba ${\times}$ P. glandulosa $F_1$, Salix alba, Pinus rigida, Alnus hirsuta var. sibirica, A. inokumai A. gultinosa, and A. incana. In One-year rotation, Lespedeza cyrtobotrya produced largest amoung of biomass (2.6 t/ha/year, fresh weight) and Populus alba ${\times}$ P. glandulosa $F_1$ the second largest (2.2 t/ha/year) on low hill. In two-year rotation, the latter produced the largest amount (4.8 t/ha/year) and Alnus hirsuta var. sibirica second largest (2.8 t/ha/year) on low hill. In three-year rotation, the largest weight (11.2 t/ha/year) was produced by Robinia pseudoacacia and the second largest (6.2 t/ha/year) by Alnus hirsuta var. sibirica on low hill Amorpha fruticosa, Acer saccharinum, Platanus orientalis and Salix alba were not suitable for biomass or fuelwood productio due to poor growth. Biomass yield on upper hill was reduced considerably for all tewlve species, with less than 4 t/year at maximum Only nitrogen fixing species (Robinia and Alnus species) are recommended on upper hill for biomass production wood sprouting ability of species was generally associated with good biomass production. Calori values of ovendry wood ranged from 4,485 cal/g for Salix alba to 5,125 cal/g for Alnus glutinosa. For maximum biomass production a three-year ratation with coppice is preferred to one-year and two-year roataions The best species appeared to be Robinia pseudoacacia and Alnus hirsuta var sibirica.

• Research in Plant Disease
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• v.15 no.3
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• pp.242-247
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• 2009

To select rotation crops for control of clubroot of Chinese cabbage, potato, corn, soybean, onion and groundsel were planted in the field infected with clubroot pathogen (Plasmodiophora brassicae) in highland area in 2000. In comparison of economical efficiency among rotation crops, potato and onion gained about 16.9 and 14.9 times higher, respectively, than successive cultivation of Chinese cabbage. Resting spore densities of Plasmodiophora brassicae after harvesting rotation crops were in the range of $0.3{\sim}1.2{\times}10^3/g$ soil in all cultivated soils with rotation crops while that of successive Chinese cabbage cultivation soil was very high as much as $89.3{\times}10^3/g$ soil. And disease severity of Chinese cabbage clubroot was 4.9, 20.2, 24.4, 25.1 and 27.8% in onion, soybean, potato, corn, and groundsel cultivation plot, respectively, while that of successive Chinese cabbage cultivation plot was very high as 77.8%. Effect of rotation period of onion, potato, soybean on disease control was investigated from 2002 to 2005. Resting spore densities of Plasmodiophora brassicae after cultivating rotation crops were decreased until $2^{nd}$ year and maintained low density at $3^{rd}$ year in all plots, while that of successive Chinese cabbage cultivation plot was increased 2.6 to 23.6 times for three years. When Chinese cabbage was rotation-cultivated with potato, soybean and onion for three years, disease severities of Chinese cabbage clubroot decreased 92 to 4.4%, 72 to 10.4% and 72 to 12.2%, respectively, while that of successive Chinese cabbage cultivation plot maintained 100%. As the rotation period increased, the yields of Chinese cabbage increased, while that of successive Chinese cabbage cultivation plot decreased. At $3^{rd}$ year, Chinese cabbage with high quality could be much more produced 2,205, 2,493 and 2,476 g in potato, soybean and onion cultivation plot, respectively, than 95 g in successive Chinese cabbage cultivation plot.