Wildfire Severity Mapping Using Sentinel Satellite Data Based on Machine Learning Approaches (Sentinel 위성영상과 기계학습을 이용한 국내산불 피해강도 탐지)
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- 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.
This study was conducted to determine effect of dietary reduced antibiotics supplementation on carcass characteristics and meat quality of finishing pigs fed stevia and charcoal. A total of 180 pigs (LYD) were randomly allocated into 3 treatments with 3 replications. Dietary treatments were 1) T1 (control, basal diet, no stevia and charcoal addition, antibiotics both in early and late fattening periods), 2) T2 (basal diet, 0.3% stevia + 0.3% charcoal, antibiotics both in early and late fattening periods), 3) T3 (basal diet, 0.3% stevia + 0.3% charcoal, antibiotics in early fattening period only). At each marketing day, pigs were conventionally slaughtered, examined the carcass characteristics and loin (Longissimus) muscles were removed for the meat quality traits. In the carcass characteristics, T3 group showed higher incidence of A carcass grade compared to the other treatments. Backfat thickness was higher in T2 group compared to the others (p<0.05). In the meat quality traits, pH was higher in T1 group than T3 group (p<0.05). Cooking loss was higher in T2 group than T1 group (p<0.05). However, WHC (water holding capacity), drip loss and shear force values did not show any significant differences among treatments. In the panel test, there were no significant differences in tenderness, juiciness, flavor, and total acceptability scores among treatments. As a result, dietary supplementation of reduced antibiotics to finishing pigs fed stevia and charcoal showed similar growth performance and meat quality traits compared to conventional method.
A feeding trial was carried out to investigate the effect of supplemental complex probiotics on performances, physio-chemica1 properties of meat and inetestinal microflora in broiler chicks. Four hundred eighty broiler chickens, one days old with mixed sexes were fed one of four diets containing 0, 0.1, 0.2 and 0.4% complex probiotics for 7 weeks. There were four replicates with thirty chicks per pen. Diet contained ME 3,100, 3,l00kcal/kg, and CP 22.0, 20.0% for starting and finishing period, respectively. Body Weight gain of chicks fed the complex probiotics tended to increase from the frist week and all complex probiotics higher than control from the 4th week. Chickens fed the diets containing 0.2% probiotics had higher(P<0.05) than those fed the other levels from the 4th week to 5th week. Feed conversion also improved significantly(P<0.05) in the supplemental 0.2% probiotics from the 4th week to 5th week. In physio-chemica1 properties of meat, carcass rate increased significantly(P<0.05) in the supplemental 0.4% probiotics compared to that of control at 7 weeks overall means and abdominal fat pad rate increased significantly(P< 0.05) in the supplemental 0.2% probiotics compared to that of control. Cooking loss decreased significantly(P<0.05) in the supplemental all probiotics. But shear force increased significantly(P<0.05) in the supplemental 0.4% probiotics. The number of ileum and cecum Lactobacillus spp. tended to increase in the supplemental complex probiotics at 7 week of age, but was not significantly different. As the result, supplemental complex probiotics increased performance and physio-chemica1 properties of meat and the number of intestinal Lactobacillus of broiler chicks.
In this research, the seismic connection details for two concrete-filled U-shape steel beam-to-H columns were proposed and cyclically tested under a full-scale cruciform configuration. The key connecting components included the U-shape steel section (450 and 550 mm deep for specimens A and B, respectively), a concrete floor slab with a ribbed deck (165 mm deep for both specimens), welded couplers and rebars for negative moment transfer, and shear studs for full composite action and strengthening plates. Considering the unique constructional nature of the proposed connection, the critical limit states, such as the weld fracture, anchorage failure of the welded coupler, local buckling, concrete crushing, and rebar buckling, were carefully addressed in the specimen design. The test results showed that the connection details and design methods proposed in this study can well control the critical limit states mentioned above. Especially, the proposed connection according to the strengthening strategy successfully pushed the plastic hinge to the tip of the strengthened zone, as intended in the design, and was very effective in protecting the more vulnerable beam-to-column welded joint. The maximum story drift capacities of 6.0 and 6.8% radians were achieved in specimens A and B, respectively, thus far exceeding the minimumlimit of 4% radians required of special moment frames. Low-cycle fatigue fracture across the beam bottom flange at a 6% drift level was the final failure mode of specimen A. Specimen B failed through the fracture of the top splice plate of the bolted splice at a very high drift ratio of 8.0% radian.
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.
This study describes the successful synthesize strategy for the silica nanoparticles utilizing various water sources, including tap, industrial, and stream waters without using deionized water. Also, as-synthesized silica nanoparticles are employed as dispersive materials for the electro-responsive smart fluid application. Specifically, homogeneous silica nanoparticles with sizes of 500-700nm are successfully prepared in large scale at once (ca. 12.0 g) with the described experimental method and showing similar structural and chemical characteristics with silica nanoparticles synthesized using the deionized water. The size of silica nanoparticles are varied according to the ion conductivity differences of tap, industrial, stream water, and deionized water. The size of silica nanoparticles decresed with the increased ion conductivity, indicating the ion suppression of growth of silica nanoparticles. Moreover, as-synthesized silica nanoparticles from various water sources of electro-responsive characteristic are investigated by the smart fluid application. The smart fluids containing silica nanoparticles synthesized by tap, industrial, and stream water exhibited higher shear stress compared to the deionized water, owing to the more rigid fibril-like structures formed by the smaller silica nanoparticles. Conclusively, uniform silica nanoparticles from various water sources without any purification are able to successfully prepared without usage of deionized water and resulting silica nanoparticles manifested higher electro-responsive performance.
This study used leaves and stems of 'Tongchaeru', one of the sweet potato varieties, to investigate broiler productivity, meat quality, blood properties, growth hormones, and immune factor levels according to drying method and amount added to feed. For this experiment, a total of 720 1-day-old male Ross 308 broilers were used. Treatments were assigned with 3 replicates per treatment and 20 birds were assigned to each replicate. The treatment group was designed into 12 treatments according to the type of natural product (leaves (L), stems (S)), drying type (natural (N), hot air (H), freeze (F)) and amount added (0.1%, 0.3%). The test was conducted for a total of 5 weeks. In this study, there was no significant difference in productivity depending on the type and amount of additives added (P>0.05). The FS 0.3% group showed high pH and WHC levels, and the shear force was lowest at HL 0.1% group (P<0.05). Blood cell and serum biochemical components were similar in all treatments, and growth hormone IGF-1 was highest in FS 0.1% group (P<0.05). There was no significant difference in IFN-γ, but the highest level of IL-6 was seen in the HS 0.1% group (P<0.05). In conclusion, the meat quality and the level of growth hormone and immune factors in the body were different depending on the type and amount of dried leaves and stems of sweet potato 'Tongchaeru', further study is needed to compare the selected additives and amounts added with those without additions.
The wall shear stress in the vicinity of end-to end anastomoses under steady flow conditions was measured using a flush-mounted hot-film anemometer(FMHFA) probe. The experimental measurements were in good agreement with numerical results except in flow with low Reynolds numbers. The wall shear stress increased proximal to the anastomosis in flow from the Penrose tubing (simulating an artery) to the PTFE: graft. In flow from the PTFE graft to the Penrose tubing, low wall shear stress was observed distal to the anastomosis. Abnormal distributions of wall shear stress in the vicinity of the anastomosis, resulting from the compliance mismatch between the graft and the host artery, might be an important factor of ANFH formation and the graft failure. The present study suggests a correlation between regions of the low wall shear stress and the development of anastomotic neointimal fibrous hyperplasia(ANPH) in end-to-end anastomoses. 30523 T00401030523 ^x Air pressure decay(APD) rate and ultrafiltration rate(UFR) tests were performed on new and saline rinsed dialyzers as well as those roused in patients several times. C-DAK 4000 (Cordis Dow) and CF IS-11 (Baxter Travenol) reused dialyzers obtained from the dialysis clinic were used in the present study. The new dialyzers exhibited a relatively flat APD, whereas saline rinsed and reused dialyzers showed considerable amount of decay. C-DAH dialyzers had a larger APD(11.70
The wall shear stress in the vicinity of end-to end anastomoses under steady flow conditions was measured using a flush-mounted hot-film anemometer(FMHFA) probe. The experimental measurements were in good agreement with numerical results except in flow with low Reynolds numbers. The wall shear stress increased proximal to the anastomosis in flow from the Penrose tubing (simulating an artery) to the PTFE: graft. In flow from the PTFE graft to the Penrose tubing, low wall shear stress was observed distal to the anastomosis. Abnormal distributions of wall shear stress in the vicinity of the anastomosis, resulting from the compliance mismatch between the graft and the host artery, might be an important factor of ANFH formation and the graft failure. The present study suggests a correlation between regions of the low wall shear stress and the development of anastomotic neointimal fibrous hyperplasia(ANPH) in end-to-end anastomoses. 30523 T00401030523 ^x Air pressure decay(APD) rate and ultrafiltration rate(UFR) tests were performed on new and saline rinsed dialyzers as well as those roused in patients several times. C-DAK 4000 (Cordis Dow) and CF IS-11 (Baxter Travenol) reused dialyzers obtained from the dialysis clinic were used in the present study. The new dialyzers exhibited a relatively flat APD, whereas saline rinsed and reused dialyzers showed considerable amount of decay. C-DAH dialyzers had a larger APD(11.70