• Journal of Drive and Control
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• v.17 no.4
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• pp.133-140
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• 2020

Traction performance of a tractor varies depending on soil conditions. Sinkage and slip of the driving wheel for tractor frequently occur in a reclaimed land. The objective of this study was to develop a tractor suitable for a reclaimed land. Traction performance was evaluated according to soil conditions of reclaimed land and paddy field. Field experiments were conducted at two test sites (Fields A: paddy field; and Field B: reclaimed land). The tractor load measurement system was composed of an axle rotation speed sensor, a torque meter, a six-component load cell, GPS, and a DAQ (Data Acquisition System). Soil properties including soil texture, water content, cone index, and electrical conductivity (EC) were measured. Referring to previous researches, the tractor traveling speed was set to B3 (7.05 km/h), which was frequently used in ridge plow tillage. Soil moisture contents were 33.2% and 48.6% in fields A and B, respectively. Cone index was 2.1 times higher in field A than in field B. When working in the reclaimed land, slip ratios were about 10.5% and 33.1% for fields A and B, respectively. The engine load was used almost 100% of all tractors under the two field conditions. Traction powers were 31.9 kW and 24.2 kW for fields A and B, respectively. Tractive efficiencies were 83.3% and 54.4% for fields A and B, respectively. As soil moisture increased by 16.4%, the tractive efficiency was lowered by about 28.9%. Traction performance of tractor was significantly different according to soil conditions of fields A and B. Therefore, it is necessary to improve the traction performance of tractor for smooth operations in all soil conditions including a reclaimed land by reflecting data of this study.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.1
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• pp.257-266
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• 2021

Urban areas can often suffer flood damage because of the more frequent catastrophic rainfall events from climate change. Flood mitigation measures consist of (1) structural and (2) non-structural measures. In this study, the proposed method focused on operating an urban drainage system among non-structural measures. The combined inland-river operation technique estimates the inflow of pump stations based on the water level obtained from a preselected monitoring point, and the pump station expels the stored rainwater to the riverside based on those estimates. In this study, the proposed method was applied to the Mokgam drainage watershed, where catastrophic rainfall events occurred (i.e., 2010- and 2011-years), and severe flood damage was recorded in Seoul. Using the proposed method, the efficiency of flood reduction from the two rainfall events was reduced by 34.9 % and 54.4 %, respectively, compared to the current operation method. Thus, the proposed method can minimize the flood damage in the Mokgam drainage watershed by reserving the additional storage space of a reservoir. In addition, flooding from catastrophic rainfall can be prevented, and citizens' lives and property in urban areas can be protected.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.32 no.6
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• pp.561-568
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• 2020

Wave measurements using X-band radar have many advantages compared to other wave gauges including wave-rider buoy, P-u-v gauge and Acoustic Doppler Current Profiler (ADCP), etc.. For example, radar system has no risk of loss/damage in bad weather conditions, low maintenance cost, and provides spatial distribution of waves from deep to shallow water. This paper presents new methods for estimating significant wave heights of X-band marine radar images using Artificial Neural Network (ANN). We compared the time series of estimated significant wave heights (Hs) using various estimation methods, such as signal-to-noise ratio (${\sqrt{SNR}}$), both and ${\sqrt{SNR}}$ the peak period (TP), and ANN with 3 parameters (${\sqrt{SNR}}$, TP, and Rval > k). The estimated significant wave heights of the X-band images were compared with wave measurement using ADCP(AWC: Acoustic Wave and Current Profiler) at Hujeong Beach, Uljin, Korea. Estimation of Hs using ANN with 3 parameters (${\sqrt{SNR}}$, TP, and Rval > k) yields best result.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.33 no.6
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• pp.217-225
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• 2021

In this study, wave spectrum data were calculated using the water surface elevation data observed at 5Hz intervals from the HeMOSU-2 meteorological tower installed on the west coast of Korea, and wave parameters were estimated using wave spectrum data. For all significant wave height ranges, the peak enhancement parameter (γ_opt) of the JONSWAP spectrum and the scale parameter (α) and shape parameter (β) of the modify BM spectrum were estimated based on the observed spectrum, and the distribution of each parameter was confirmed. As a result of the analysis, the peak enhancement parameter (γ_opt) of the JONSWAP spectrum was calculated to be 1.27, which is very low compared to the previously proposed 3.3. And in the range of all significant wave heights, the distribution of the peak enhancement parameter (γ_opt) was shown as a combined distribution of probability mass function (PMF) and probability density function (PDF). In addition, the scale parameter (α) and shape parameter (β) of the modify BM spectrum were estimated to be [0.245, -1.278], which are lower than the existing [0.300, -1.098], and the result of the linear correlation analysis between the two parameters was β = -3.86α.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.39 no.6
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• pp.429-435
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• 2021

The integrated underground space map shows the underground facility(water supply, sewage, gas, electric power, communication, heating), underground structures (subway, underpass, underground walkway, underground parking lot, underground shopping mall, common ward), ground(drilling, coffin, geology) refers to a map constructed so that a total of 15 types of underground information can be checked at a glance on a three-dimensional basis. The purpose of this study is to develop a technology to correct the problem of curved surface processing and the unevenness of underground facility pipelines that occur in converting 2D underground facility data into 3D-based underground space integrated map(3D underground facility model). do it with. To this end, we first investigated and reviewed the domestic and foreign status of technologies that generate data on underground facilities based on three dimensions, and developed a surface correction algorithm and an unevenness correction algorithm to solve practical problems. Algorithms to verify the developed algorithm This applied correction program was developed. Based on the above process, the three-dimensional model of the underground facility could be produced identically to reality. This study is judged to have significance as a basic study to improve the utilization of the underground spatial integration map.

• Journal of Ecology and Environment
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• v.45 no.4
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• pp.277-286
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• 2021

Background: As trade increases, the influx of various alien species and their spread to new regions are prevalent and no longer a special problem. Anthropogenic activities and climate changes have made the distribution of alien species out of their native range common. As a result, alien species can be easily found anywhere, and they have nothing but only a few differences in intensity. The prevalent distribution of alien species adversely affects the ecosystem, and a strategic management plan must be established to control them effectively. To this end, hot spots and cold spots were analyzed according to the degree of distribution of invasive alien plants, and major environmental factors related to hot spots were found. We analyzed the 10,287 distribution points of 126 species of alien plants collected through the national survey of alien species by the hierarchical model of species communities (HMSC) framework. Results: The explanatory and fourfold cross-validation predictive power of the model were 0.91 and 0.75 as AUC values, respectively. The hot spots of invasive plants were found in the Seoul metropolitan area, Daegu metropolitan city, Chungcheongbuk-do Province, southwest shore, and Jeju island. Generally, the hot spots were found where the higher maximum temperature of summer, precipitation of winter, and road density are observed, but temperature seasonality, annual temperature range, precipitation of the summer, and distance to river and sea were negatively related to the hot spots. According to the model, the functional traits accounted for 55% of the variance explained by the environmental factors. The species with higher specific leaf areas were more found where temperature seasonality was low. Taller species preferred the bigger annual temperature range. The heavier seed mass was only preferred when the max temperature of summer exceeded 29 ℃. Conclusions: In this study, hot spots were places where 2.1 times more alien plants were distributed on average than non-hot spots (33.5 vs 15.7 species). The hot spots of invasive plants were expected to appear in less stressful climate conditions, such as low fluctuation of temperature and precipitation. Also, the disturbance by anthropogenic factors or water flow had positive influences on the hot spots. These results were consistent with the previous reports about the ruderal or competitive strategies of invasive plants instead of the stress-tolerant strategy. The functional traits are closely related to the ecological strategies of plants by shaping the response of species to various environmental filters, and our result confirmed this. Therefore, in order to effectively control alien plants, it is judged that the occurrence of disturbed sites in which alien plants can grow in large quantities is minimized, and the river management of waterfronts is required.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.40 no.5
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• pp.413-419
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• 2022

As the development of the underground space becomes active, safety accidents related to the underground are frequently occurring in recent years. In this regard, the Ministry of Land, Infrastructure and Transport is enforcing the 『Special Act on Underground Safety Management』 (enforced on January 1, 2018, hereafter referred to as the Underground Safety Act). Among the core contents of the Underground Safety Act, underground facilities(water supply, sewage, gas, power, communication, heating) buried underground, underground structures(subway, underpass, underpass, underground parking lot, underground shopping mall, common area), ground (Drilling, wells, geology) of 15 types of underground information can be checked at a glance on a three-dimensional basis by constructing an integrated underground spatial map and using it. The purpose of this study is to develop a program that can quickly inspect the three-dimensional model after creating a three-dimensional underground structure data among the underground spatial integration maps. To this end, we first investigated and reviewed the domestic and foreign status of technology that generates and automatically inspects 3D underground structure data. A quality inspection program was developed. Through this study, it is judged that it will be meaningful as a basic research for improving the quality of underground structures on the integrated map of underground space by automating more than 98% of the 3D model inspection process, which is currently being conducted manually.

• Applied Chemistry for Engineering
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• v.33 no.1
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• pp.28-37
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• 2022

The lignite and bituminous coal are mainly used in thermal power plant. They exhaust green house gas (GHG) such as CO₂, and become deplete, thus require alternative energy resources. To solve the problem, the hydrochar production from biomass is suggested. In this study, both hydrothermal carbonization (HTC) and solvothermal carbonization (STC) were used to produce high quality hydrochar. To improve the reactivity of water solvent process in HTC, STC process was conducted using ethanol solution. The experiments were carried out by varying the solid-liquid ratio (1:4, 1:8, 1:12), reaction temperature (150~300 ℃) and retention time (15~120 min) using kenaf. The characteristic of hydrochar was analyzed by EA, FT-IR, TGA and SEM. The carbon content of hydrochar increased up to 48.11%, while the volatile matter decreased up to 39.34%. Additionally, the fuel characteristic of hydrochar was enhanced by reaction temperature. The results showed that the kenaf converted to a fuel by HTC and STC process, which can be used as an alternative energy source of coal.

• The Korea Journal of Herbology
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• v.37 no.5
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• pp.63-74
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• 2022

Objective : Gastritis refers to an inflammatory disease of the gastric mucosa. Alcohol is one of the main aggression factors, causing bleeding and inflammation in the gastric mucosa and it is known to not only increase lipid peroxide levels, but also deplete key antioxidant factors. The purpose of this study was to determine the effect of Uncariae Ramulus et Uncus water extract (URW) in alcohol-induced gastritis. Methods : The total polyphenol and flavonoid contents of URW were confirmed through an in vitro experiment. Also, 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging activity and ferric reducing antioxidant power (FRAP) activity were confirmed. For in vivo experiments, mice were divided into 4 groups (n=8). Also, 1 hr after oral administration of each drug, 50% ethanol was orally administered to induce gastritis. Results : As a result of in vitro experiments, URW showed excellent antioxidant activity. In alcohol-induced gastritis, URW alleviated the damage to the gastric mucosa caused by alcohol. Also, URW decreased reactive oxygen species (ROS) and malondialdehyde (MDA) levels in serum and gastric tissues, and significantly decreased the expression of NADPH oxidases in gastric tissues. In addition, it significantly modulated the nuclear factor erythroid-derived 2-related factor 2 (Nrf2) and nuclear factor-𝜅B p65 (NF-𝜅B) pathways as well as significantly increased the expression of anti-inflammatory proteins. Conclusions : These results suggest that URW not only reduces oxidative stress through excellent antioxidant activity but also relieves gastric mucosal inflammation as a regulator of Nrf2 and NF-𝜅B pathways.

• Animal Bioscience
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• v.35 no.12
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• pp.1892-1903
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• 2022

Objective: A series of experiment were conducted to evaluate the effects of replacing a part of soybean meal (SBM) at 6% of broiler diets with fermented soybean meal (FSBM) obtained by single or two-stage fermentation by measuring growth performance, antioxidant activity in the jejunum and distal intestinal microflora. Methods: Soybean meal samples were prepared by single-stage fermentation using Bacillus velezensis (Bv) (FSBM_B), or Lactobacillus spp. (as commercial control) (FSBM_L). Additional SBM sample was prepared by two-stage fermentation using Bv and subsequently using Lactobacillus brevis ATCC 367 (Lb) (FSBM_B+L). Enzyme activity, chemical composition, trichloroethanoic acid-nitrogen solubility index (TCA-NSI) and antioxidant activity were measured. Then, in an in vivo study, 320 Ross308 broilers were divided into four groups with ad libitum supply of feed and water. Four groups were fed either a corn-soybean meal diet (SBM), or one of fermented SBM diets (FSBM_B+L, FSBM_B, and FSBM_L). Growth, serum characteristics, microflora, and the mRNA expression of selected genes were measured. Results: Compared to SBM, FSBM_B+L contained lower galacto-oligosaccharide, allergic protein, and trypsin inhibitor, and higher TCA-NSI by about three times (p<0.05). Reducing power and 1,1-diphenyl-2-picrylhydrazyl free radical scavenging ability correlated positively with the TCA-NSI content in FSBM. Growth performances were not significantly different among four groups. In jejunum of 35-day-old broilers, partial replacement of SBM by FSBM_B+L increased the activity of superoxide dismutase and catalase (CAT), and the FSBM_B group had the highest catalase activity (p<0.05). Partial replacement of SBM by FSBM increased relative mRNA expressions of nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), and peptide transporter 1 (PepT1) (p<0.05); however, FSBM_B+L increased CAT mRNA level to 5 times of the control (p<0.05). Conclusion: Using Bv- and Lb-processed SBM through two-stage fermentation to partially replace 6% of diets will improve the gut's antioxidant activity under commercial breeding in broilers.