• Journal of the Institute of Convergence Signal Processing
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• v.9 no.1
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• pp.31-38
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• 2008

Ad-Hoc network is a network architecture which has no backbone network and is deployed temporarily and rapidly in emergency or war without fixed mobile infrastructures. All communications between network entities are carried in ad-hoc networks over the wireless medium. Due to the radio communications being extremely vulnerable to propagation impairments, connectivity between network nodes is not guaranteed. Therefore, many new algorithms have been studied recently. This study proposes the secondary header approach to the cluster based routing protocol (CBRP). The primary header becomes abnormal status so that the primary header can not participate in the communications between network entities, the secondary header immediately replaces the primary header without selecting process of the new primary header. This improves the routing interruption problem that occurs when a header is moving out from a cluster or in the abnormal status. The performances of proposed algorithm ACBRP(Advanced Cluster Based Routing Protocol) are compared with CBRP. The cost of the primary header reelection of ACBRP is simulated. And results are presented in order to show the effectiveness of the algorithm.

• Food Science and Preservation
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• v.21 no.3
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• pp.412-420
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• 2014

This study was performed to investigate the effect of fermented Hovenia dulcis Thunb fruit water extract on biomarkers for acute (a) ethanol-induced hangover and chronic (c) ethanol-induced liver injury in rats. For acute ethanol-induced hangover, the rats were administered distilled water (D.W., 10 mL/kg body wt.), Hovenia dulcis Thunb fruit water extract (HWE, 400 mg/10 mL/kg body wt.) and fermented HWE (FHWE, 400 mg/10 mL/kg body wt.), respectively, before 40% ethanol (5 g/kg body wt.) was administered. For chronic ethanol-induced liver injury, the rats were randomly divided into the normal control (cNC), ethanol (cET), cET-HWE and cET-FHWE groups. The cNC and cET groups were administered D.W. (10 mL/kg body wt.) before 40% alcohol (5 g/kg body wt.) was administrered for 21 days. The cET-HWE and cET-FHWE groups were administered HWE (400 mg/10 mL/kg body wt.) and FHWE (400 mg/10 mL/kg body wt.), respectively before 40% ethanol (5 g/kg body wt.) administration for 21 days. For acute ethanol-induced hangover, the serum alcohol and acetaldehyde concentrations were more significantly reduced in the aHWE and aFHWE groups than in the aET group. Moreover, the effect of FHWE was greater than that of HWE. For chronic ethanol-induced liver injury, the serum ethanol, acetaldehyde, ${\gamma}$-glutamyl transpeptidase (${\gamma}$-GTP) levels and the hepatic lipids concentration more significantly dropped in the cET-HWE and cET-FHWE groups than in the cET group. The FHWE administration showed faster recovery of the serum glucose concentration than in the cET and cET-HWE groups. The body weight reduction tended to normalize in the cET-HWE and cET-FHWE groups, which is ideal for chronic ethanol administration. These results suggest that FHWE has a protective effect against ethanol-induced liver damage, as evidenced by its ability to lower the serum ethanol and acetaldehyde concentrations after alcohol administration, and by its ability to decrease the level of ${\gamma}$-GTP and hepatic lipids. FHWE also elevated serum glucose concentration. Therefore, FHWE is effective in reducing ethanol-induced hangover and can play a beneficial role in the treatment of ethanol-induced liver damage as well as body weight reduction.

• Journal of Digital Convergence
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• v.18 no.5
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• pp.179-186
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• 2020

The purposes of this paper were: 1) to identify the structural changes of the northeast Asia airport network caused by the pandemic of COVID-19 using social network analysis (SNA) and 2) to suggest proposals for improving airport competitiveness. In this respect, the entire international air routes in northeast Asia airport collected data of 4-10 March 2019 and 9-15 March 2020 through schedules analyzer database of OAG. We found that both the density and centrality have decreased since the spread of COVID-19. The government and airport authorities need active support such as a reduction of various fees and a moratorium on transportation rights to overcome the crisis in the air transport industry. When the COVID-19 situation calms down in the future, we hope that further research will be conducted to identify the structural changes in the SNA aspects through the vast data establishment in countries such as the EU and America.

• Food Science and Preservation
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• v.30 no.5
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• pp.811-821
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• 2023

This study investigated the storability of onions according to manual and mechanical harvesting. Moreover, we simulated the onion-to-onion impact during the mechanical harvesting process and investigated the storability after artificially subjecting the onions to impact treatment. The onion harvesting methods included hand plucking + manual collection, digger + manual, and digger + mechanical collection. The maximum impact height during the mechanical harvesting process was 0.5 m. Immediately after harvesting, no significant difference in the bruise and wound rate among the harvesting methods was observed. Any increased bruise or wound rate because of mechanical harvesting was presumed to be influenced by soil conditions, such as the presence of gravel, and machine operation factors. Furthermore, the storability during the 8.5 months storage showed no significant difference according to the harvesting methods. In treatments by simulating the impacts during the mechanical harvesting process, the impact heights were 0.0 m (0.0 J), 0.25 m (0.86 J), 0.5 m (1.72 J), and 0.75 m (2.57 J), each performed once, and four times at the same position (3.43 J) and four times at different positions (3.43 J) at 0.25 m. Throughout all the treatments, there were no significant differences in the storability during the 8.5 months storage period.

• Korean Journal of Environment and Ecology
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• v.34 no.4
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• pp.345-354
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• 2020

The purpose of this study was to investigate the effects of soil amendment treatments, such as hydroball, and active carbon, and planting Pennisetum alopecuroides for reducing calcium chloride (CaCl₂) of soil leachate and the growth of Pennisetum alopecuroides. The experiment planted Pennisetum alopecuroides in a plastic pot with a diameter of 10 cm and a height of 9 cm in a greenhouse April-October 2018. The experimental group comprised six treatments, including Non-treatment (Cont.), Hydroball (H), Active carbon (AC), planting Pennisetum alopecuroides (P), hydroball + planting Pennisetum alopecuroides (H + P), and active carbon + planting Pennisetum alopecuroides (AC + P). The dissolution of the CaCl₂ concentration 200ml of 10g/L was irrigated once every two weeks. We measured the growth (plant height, leaf length, leaf width, number of leaves), EC, pH, and exchangeable cations (K⁺, Ca²⁺, Na⁺, and Mg²⁺) according to the high concentration of CaCl₂ in the plant and soil leachate. In a treatment with the 'hydroball' amendment, the soil leachate electrical conductivity (EC), and the cation exchangeable were decreased more than those of the control, while the growth of Pennisetum alopecuroides relative growth rate(RGR) increased. Overall, application with the hydroball amendment added the planting of Pennisetum alopecuroides improved the salt reduction effect more than the control group. These results indicate that the application of the soil amendment agent hydroball was suitable soil amendments in accordance with the high concentration of calcium chloride (CaCl₂). Also, Planting Pennisetum alopecuroides is expected to be appropriate for salt-tolerant plant for soil affected by deicing salt agents.

• Transactions of the Korean hydrogen and new energy society
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• v.31 no.4
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• pp.387-394
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• 2020

A parametric study of a 2.5 kW class propeller type micro hydraulic turbine was performed. In order to analyze the internal flow characteristics in the hydraulic turbine, three dimensional Reynolds-averaged Navier-Stokes equations with shear stress transport turbulence model were used and the hexahedral grid system was used to construct computational domain. To secure the reliability of the numerical analysis, the grid dependency test was performed using the grid convergence index method based on the Richardson extrapolation, and the grid dependency was removed when about 1.7 million nodes were used. For the parametric study, the axial distance at shroud span (L) between the inlet guide vane and the runner, and the inlet and outlet blade angles (β₁, β₂) of the runner were selected as the geometric parameters. The inlet and outlet angles of the runner were defined in the 3 spans from the hub to tip, and a total of 7 geometric parameters were investigated. It was confirmed that the outlet angles of the runner had the most sensitive effect on the power and efficiency of the micro hydraulic turbine.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.3
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• pp.148-154
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• 2018

When shooting small arms, the inner surface temperature is heated up to about $700{\sim}1,000^{\circ}C$ by the friction of the bullet and the inner wall of the barrel and the combustion of propellant. High-temperature propellant gas and high-speed movement of the bullet cause corrosion of the inner wall, which is noticeable immediately in front of the chamber. In this study, the mechanical properties of Cr-Mo-V steel, which is the base material, were tested using Taguchi experimental design to find the best nitriding treatment conditions. For the nitriding process, the working time, salt bath temperature, and salt concentration were combined as three conditions and placed in the $L_9(3^4)$, orthogonal array table. The thicknesses of the white layer and the nitrogen diffusion layer were measured after nitriding under each condition in a salt bath furnace. Durability was evaluated by measuring the degree of dispersion through actual shooting because it was difficult to evaluate the mechanical properties of the cylinder inner structure. As a result, it was confirmed that the durability was optimal at $565^{\circ}C$, 1 hour, 0.5%. These optimal conditions were selected by the statistical analysis of the Minitab program(ver.17).

• Journal of Industrial Convergence
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• v.17 no.4
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• pp.9-14
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• 2019

This paper presents several problems that can occur in the development of the ultra-compact LED package of less than 1.0mm and introduces the solution to them. In the existing mold structure, since the upper and lower core parts are integrated, various errors have occurred due to the roughness of EDM in the small model, which is a limiting factor in further reducing the mold size. As a countermeasure, the prefabricated model was presented in an earlier study to overcome the obstacles to the development of a ultra-compact LED package. In this paper, several problems have been found during the fabrication of prototypes as a starting work to produce the results for the presented model. The types are suggested and the solutions are discussed. And by changing the existing 2-row structure to 3-row structure in the same size lead frame, the aspect of efficient production is considered. The experimental procedure verifies the proposed solution and conducts a test to produce a prototype to confirm that a good product can be produced.

• Journal of the Korean Society of Food Culture
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• v.37 no.1
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• pp.73-80
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• 2022

The purpose of this study was to evaluate cookies prepared with five different quantities (0, 5, 10, 15, and 20%) of watermelon powder (WP). This study analyzed quality characteristics, consumer liking, and CATA (check-all-that-apply) of the samples. The density and pH of the cookie dough and the L-value of the cookies tended to decrease as the amount of watermelon powder increased (p<0.05), whereas the spread factor, a-value, and hardness of the cookies tended to increase as the amount of watermelon powder increased (p<0.001). The b-value tended to increase up to WP10, but it tended to decrease from WP15 (p<0.001). The results of the evaluation of consumer liking showed that overall liking was the highest for WP5 and lowest for WP20 (p<0.05). In the analysis of the CATA survey, the main reasons for liking for all the samples were 'Appearance', 'Color', 'Sweet taste', 'Nutty odor/flavor', 'Crispiness', and 'Familiarity'. WP5 showed the most diverse reasons for being liked. The common reason for disliking samples with the addition of watermelon powder was 'Residual feel in the mouth'. In the correspondence analysis, attributes of 'Stale taste', 'Clean taste', 'Softness', 'Familiarity', 'Moistness', 'Color', 'Blandness' were detected in the WP0 and WP5. The results indicate that WP5 with a 5% supplementation of watermelon powder is appropriate for improving the quality and consumer acceptability of the cookies.

• Journal of Veterinary Clinics
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• v.41 no.1
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• pp.8-17
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• 2024

This study was conducted to explore the efficacy of bee venom as a treatment for mastitis and to determine the optimal dosage and treatment period. When 6 mg or 12 mg of bee venom was administered to each experimental quarter of mastitis in dairy cow, the clinical symptoms in the 12 mg quarter were noticeably improved compared to those in the 6 mg quarter. There was no significant difference in the somatic cell count (SCC) in the milk between normal and mastitis quarters between the 6 and 12 mg doses, but there was a steady decrease in the 12 mg-treated quarter (p = 0.34). To determine the treatment period, bee venom was administered for 2, 4, and 7 days. After administering 12 mg of bee venom for 7 days, the SCC in the milk was compared before 6 days and after 7 days, and the SCC was significantly decreased to less than 100,000 SC/mL after 7 days (p = 0.01). In addition, to investigate the efficacy of bee venom, the minimum inhibitory concentration for S. aureus, E. coli, and coagulase negative staphylococci was measured, and the results showed that Gram-positive bacteria were more sensitive to bee venom than Gram-negative bacteria, and treatment for Gram-negative bacteria was limited. As a result of this study, it was confirmed that a dose of 12 mg of bee venom and a treatment period of more than 7 days were required to treat mastitis, and that treatment with bee venom alone against Gram-negative bacteria was negative.