• Korean Journal of Remote Sensing
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• v.36 no.5_3
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• pp.1109-1123
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• 2020

In South Korea with forest as a major land cover class (over 60% of the country), many wildfires occur every year. Wildfires weaken the shear strength of the soil, forming a layer of soil that is vulnerable to landslides. It is important to identify the severity of a wildfire as well as the burned area to sustainably manage the forest. Although satellite remote sensing has been widely used to map wildfire severity, it is often difficult to determine the severity using only the temporal change of satellite-derived indices such as Normalized Difference Vegetation Index (NDVI) and Normalized Burn Ratio (NBR). In this study, we proposed an approach for determining wildfire severity based on machine learning through the synergistic use of Sentinel-1A Synthetic Aperture Radar-C data and Sentinel-2A Multi Spectral Instrument data. Three wildfire cases-Samcheok in May 2017, Gangreung·Donghae in April 2019, and Gosung·Sokcho in April 2019-were used for developing wildfire severity mapping models with three machine learning algorithms (i.e., Random Forest, Logistic Regression, and Support Vector Machine). The results showed that the random forest model yielded the best performance, resulting in an overall accuracy of 82.3%. The cross-site validation to examine the spatiotemporal transferability of the machine learning models showed that the models were highly sensitive to temporal differences between the training and validation sites, especially in the early growing season. This implies that a more robust model with high spatiotemporal transferability can be developed when more wildfire cases with different seasons and areas are added in the future.

• Korean Journal of Weed Science
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• v.31 no.3
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• pp.260-270
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• 2011

This study was carried out to examine the effect of rice bran, barley bran, burned rice bran, and burned barley bran on the growth and yield of Chinese chive (Allium tuberosum Rottler), taro (Colocasia esculenta), and weed control. When the above 4 brans were examined 13, 27, 41 and 57 days respectively after application, the plant height of Chinese chive applied with burned barley bran was significantly higher than non-treated control, whereas the other brans did not have any distinct effect on the plant height or population number of Chinese chive. However, when examined 57 days after the application of the above 4 brans, all the plants applied with brans showed more than twice the improvement in shoot fresh weight compared with non-treated control. A chemical analysis of soil 57 days after the application of the above 4 brans showed that the soils were richer in available phosphate and organic matter. Shoot fresh weight of Chinese chive at 2 weeks after cutting was significantly higher in barely bran treated plot than in non-treated plot. In the case of taro, only taro plots transplanted when 10 cm tall and applied with barley bran showed an improvement in growth increment of both the underground and above parts. However, when sowed seeds after the application of the 4 brans, the yield of taro was reduced by the brans. Thus this research indicates that the effect of brans is differ based on the amount of bran application as well as crops. The effect of weed control on Echinochloa crus-galli, Digitaria clliaris, Chenopodium album, and Solanum nigrum as affected by brans was very low in pot conditions. Weed efficacy of the brans was also very low in field conditions. Growth of Chinese cabbage and garland chrysanthemum was inhibited 63% and 37% by rice bran at $4,000kg\;ha^{-1}$, respectively, but other crops such as maize, squash, cucumber, and Chinese chive were inhibited by 0-20%. These results were similar to that of barley bran except for Chinese cabbage.

• Journal of The Korean Society of Grassland and Forage Science
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• v.32 no.2
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• pp.149-156
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• 2012

his experiment was carried out to evaluate the effects of nitrogen top dressing levels on the growth, feed value, and anthocyanin content for developing functional feed of colored barley. A colored barley cultivar, Boanchalbori, was tested in this experiment. Nitrogen top dressing levels was six (0, 20, 40, 60, 80, 100%) and top dressing time was a regeneration time. In case of productivity, heading data was get behind and dry matter rate was significant decreased with higher nitrogen top dressing levels (p<0.05). Fresh yield, dry matter yield and TDN yield was increased with higher nitrogen top dressing levels, but not significant. In case of feed value, crude protein content was significant increased with higher nitrogen top dressing levels (p<0.05), and higher in the order of spike, whole and leaf culme of the plant. Percent NDF and ADF was decreased with higher nitrogen top dressing levels in leaf culme, but no difference in spike and whole (p<0.05), and higher in the order of leaf culme, whole and spike of the plant. TDN was increased with higher nitrogen top dressing levels in leaf culme, but no difference in spike and whole (p<0.05), and higher in the order of spike, whole and leaf culme of the plant. Total anthocyanin content was significant decreased with higher nitrogen top dressing levels in leaf culme and whole (p<0.05), and higher in the order of leaf culme, whole and spike of the plant. Specially, cyanidin-3-glucoside (C3G), delphinidin (Del), malvidin-3-glucoside (M3G) and malvidin (Mal) show a significant decrease. So there are an accumulation of anthocyanin in the culm, and standard nitrogen top dressing levels dressing on the regeneration time for produces high anthocyanin content of the colored barley.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.32 no.1
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• pp.16-22
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• 2023

Esthetic factors are very important in the success of maxillary anterior implant restoration. However, achieving esthetic results is difficult, especially in cases where periodontitis has resulted in severe alveolar bone loss. In the case of maxillary anterior teeth, the alveolar ridge resorption that begins immediately after tooth extraction interferes with the esthetic implant restoration. Therefore immediate implant placement can be performed to minimize the alveolar ridge resorption. However, in severe bone loss cases, immediate implant placement could result in esthetic failure, and this result might cause irreparable problems. We can also perform alveolar ridge preservation and then place implants later. On JCP published in 2019, there is the consensus of European academy of periodontology on the extraction socket management and the timing of implant placement. This consensus states that alveolar ridge preservation should be considered when there is severe labial bone loss in an esthetically important area such as maxillary anterior region. On performing the alveolar ridge preservation, we cannot obtain the primary wound closure, so secondary wound healing is induced with open membrane technique or soft tissue grafting should be performed for primary wound closure. However, the secondary wound healing can have a negative impact on bone regeneration, and soft tissue grafting such as FGG or CT graft can be burdensome for both patients and dentists. On the other hand, by using the granulation tissue in the extraction socket, primary closure can be achieved without soft tissue grafting. Also some studies have shown that granulation tissue in periodontal defects contains stem cells that may help in tissue regeneration. Based on this, implant restorations were performed on maxillary anterior teeth with severe alveolar bone loss by alveolar ridge preservation using granulation tissue. In spite of the severe bone defect of the extraction socket, relatively esthetic results could be obtained in implant restorations.

• Journal of Korean Society of Forest Science
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• v.76 no.2
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• pp.109-118
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• 1987

The purpose of this study was to investigate the inhabiting ecology of wild birds using artificial nests in Gyeongnam province. The sort of birds, the utilization of artificial nests by the materials, by the sites and by the forest type, and other inhabiting ecology of birds were investigated from 1984 to 1986. The results obtained were as follows; 1. Wild birds in surveyed areas were classified into 20 families and 35 species. Among them the birds inhabiting the artificial nests were 6 species and those using them most frequently were Parus ater (17.2%), P. major (16.7%) and P. palustris (12.2%). 2. The artificial nests installed on the top and at the toot of the mountain were chiefly utilized by P. ater and P. major, but the artificial nests in park area were mostly used by Passer montanus and Sturnus cineraceus. 3. Sixty-one percent of the artificial nests were utilized by the birds; 45.5% were used for breeding and 15.6% were inhabitation only. 4. When different nest materials and shapes were tested, mixed nests (sawdust and cement) were used most frequently, and C type. (Diamond shape) of wood nests was used more frequently compared with the A (Roof shape) and B (Box shape) types of wood nests. Meanwhile, the birds prefered the 3cm hole size (81.1% of utilization) to 4cm of hole (57.8%) and 5cm of hole (24.4%). 5. The artificial nests constructed in mixed forest were more frequently inhabited (73.3%) by the birds than coniferous forest (68.3%) and broad-leaved forest (63.3%). 6. The period of egg-laying in Parus species was from late April to early May, while Eophona migratoria, Lanius bucephalus, Motacilla alba and Passer montanus laid eggs generally in the middle of May. 7. Parus species, Passer montanus and Motacilla alba laid one egg every day for 5-10days, but Eopphona migratoria laied 4 eggs in 7 days and Lanius bucephalus laid 5 eggs in 4 days. The incubation period of Parus species was 16-18 days, while the others were about 11 to 14 days. 8. Thirteen days after the hatch of Parus major, chicks reached 13.9g of body weight, 72.0mm of wing-length and 20.9mm of tarsus length. P. montanus chicks reached 20.3g of weight, 66.2mm of wing-length and 20.2mm of tarsus length during the same period. 9. Food item of feeding chicks almost consisted of creatures (98.2%) with following composition; 55.2% of insect larvae, 37.2% adult insects, 2.8% of pupae and 2.8% of spiders. Vegetable items were 2% only. Among those creature food items, 95.2% were insect pests to forest.

• Journal of The Korean Society of Grassland and Forage Science
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• v.3 no.2
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• pp.100-111
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• 1983

The research results reported herein had the objectives to understand and analyze the present problems of saemaeul woodland joint cattle grazing system in Kang Won Do and to take steps of improvement. The study results on actual management conditions, problems analyzed and improvement plan of total 208 joint cattle grazing area which was established 105 area in 1981 and 103 area in 1982 were summarized as follows: 1. the effectiveness of joint cattle grazing projects 1) Average daily weight gain of cattle during joint cattle grazing period was 0.4kg, showing higher daily than the conventional feeding of 0.33kg. 2) Increase of total farm income over the conventional feeding system were \1,031,357,320 during the grazing period from May to October in 1982 by adapting the 208 joint cattle grazing system, of which effectiveness of weight gain was \293,075,300 and labor saving was \543,838,750. 3) According to the results of questionaire investigation from 208 joint cattle grazing area, effectiveness of joint cattle grazing system over the conventional system were (1) labor saving, (2) feed cost saving, (3) reduced diseases, (4) increase of number of feeding, (5) inspiration of joint endeavor, (6) effect of more gain, (7) easiness of feeding and feed cost savings. 2. Problems of joint cattle grazing system. 1) Shortages of grass were a problem at second year of joint cattle grazing period due to the low regrowth rate of wild grass. 2) Proper land for woodland joint cattle grazing is belonging to land of Government ownership and it is very hard to get the permission from office of forestry for cattle grazing purpose. 3) It is also difficult to find a proper time of breeding in grazing area by the difficulty of estrus detection. 4) There are a difficulty to give a proper vaccination and medical examination for the grazing cattle. 3. Improvement plans for woodland joint cattle grazing projects. 1) Obtain sufficient roughages by hoof cultivation and oversowing pasture from the second year of joint cattle grazing period. 2) In order to increase the beef production and to use for a calf production area, Government should arrange that all proper grazing land of Government owned in Kang Won Do convert into woodland joint cattle grazing area. 3) Make a good reproductive record by mixed grazing with a excellent breeding cow in a remote area. And carry out the collective artificial insemination with synchronous puberty induced by injection of puberty stimulation hormone. 4) Make a preventive injection for blackleg, twice medication of fasciola hepatica in a year, and spray and medication of tick insecticide. 4. A policy towards upbringing of woodland joint cattle grazing area. 1) Government should thoroughly investigate about a proper land for woodland joint cattle grazing from all forests. 2) When the area is suitable for the woodland joint cattle grazing, though it is national forest or restricted area, government should make it possible to establish a grazing area. 3) On the proper land foe joint cattle grazing in the remote place, Government should support for the road construction and electric fence equipments by using of national funds. 4) There should be an administrative consideration for well promotion of the project that make woodland joint cattle grazing suitable to the characteristics of Kang Won Do. 5) In order to improve the reproduction record, Government should reform the insufficiency of artificial insemination in the joint cattle grazing area. 6) In order to maintain a proper price of cow, Government should carry out the price plan. 7) When there is any request for grassland formation in the woodland joint cattle grazing area, Government should permit it with preference.