• Korean Journal of Veterinary Service
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• v.46 no.2
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• pp.147-156
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• 2023

Between February 2020 and September 2021, a total of 452 dairy calves with diarrhea were investigated across 17 dairy farms in Gyeonggi province, Korea, using a rapid diagnostic kit. The study aimed to examine the infection rates of major pathogens causing diarrhea in dairy calves, categorizing them by season, age, and birth month. Additionally, logistic regression analysis was conducted to investigate the factors affecting the infection rate. The infection rates of the major pathogens causing infectious diarrhea in dairy calves, including bovine rotavirus, bovine coronavirus, Cryptosporidium, and E. coli, are influenced by season, age, and birth month. Bovine coronavirus and Cryptosporidium showed variations in infection rates according to season, age, and birth month, while bovine coronavirus was influenced by age and birth month, and E. coli showed variations in infection rates based on age. Furthermore, in the analysis of risk factors influencing the infection rates of these pathogens, age and birth month were identified as risk factors for bovine rotavirus, bovine coronavirus, and Cryptosporidium.

• Journal of Applied Biological Chemistry
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• v.49 no.4
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• pp.143-147
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• 2006

A rapid PCR-based assay for detecting hepatitis B viral DNA(HBV DNA) in serum and plasma was developed using a new PCR instrument named GenSpector(TMC-1000, Samsung electronics). PCR was carried out using a chip-based platform, which enabled 50 PCR cycles with internal controls, and melting-curve analysis in 30 minutes. Verification of the amplified HBV DNA product and the internal control was based on specific melting temperatures(Tm) analysis, executed by the GenSpector software. Primers were designed within the region conserved through HBV genotypes A to F. The lower limit of detection was 840 copies/ml serum, conducted with serial dilutions of a HBV DNA positive control(ACCURUN 325 series 700, Boston Biomedica Inc.). The assay was also compared to another assay for HBV DNA(Versant HBV DNA 3.0 assay, Bayer HealthCare) for 200 samples(each 100 clinical negative and positive samples). The sensitivity and specificity were 100% matched. This rapid PCR-based assay is specific, reproducible, and enables qualitative detection of HBV DNA.

• The korean journal of orthodontics
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• v.49 no.3
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• pp.150-160
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• 2019

Objective: This study aimed to analyze the effect of changing various parameters of the bone-borne rapid palatal expander (RPE) using the finite element method (FEM). Methods: In eight experimental groups, we investigated the effect of the number, position, and length of miniscrews; positional changes of the expander; and changes in the hook length on maxillary expansion. In finite element analysis, we compared the magnitude and distribution of stress, and the displacement changes following expansion of the bone-borne RPE. Results: When we compared the number and position of miniscrews, placing miniscrews in the anterior and posterior sides was advantageous for maxillary expansion in terms of stress distribution and displacement changes. Miniscrew length did not significantly affect stress distribution and displacement changes. Furthermore, anteroposterior displacement of the expander did not significantly affect transverse maxillary expansion but had various effects on vertical changes of the maxilla. The maxilla rotated clockwise when the miniscrews were placed in the anterior region. The hook length of the expander did not show consistent results in terms of changes in stress distribution and magnitude or in displacement changes. Conclusions: The findings of this study suggest that changes in the location and length of the miniscrews and displacement of the bone-borne RPE could affect the pattern of the maxillary expansion, depending on the combination of these factors.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.34 no.6
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• pp.29-34
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• 2018

In this research, regarding the cement supplied to ready mixed concrete plant, the feasibility of rapid acquisition test for cement fineness using hydrometer which used for early strength evaluation of concrete was analyzed. Additionally, regarding the rapid test with hydrometer control factors were provided. As a result of analysis, quality control using hydrometer was possible with the regressive equation obtained in five minute between density of suspension and fineness of cement powder. As the control factors, dispersing admixture, replacing kerosene as a medium, and temperature of cement and water were evaluated. According to the control factor evaluation, the tap water was optimum as a medium and calibration of keeping the temperature of water to $20^{\circ}C$ or correction factor was needed for density results. Finally, it is considered that the suggested rapid quality evaluation method using hydrometer is cheaper and easier method than currently used Blaine test.

• Journal of the Korean Geotechnical Society
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• v.39 no.10
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• pp.27-39
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• 2023

To effectively manage flood risk, it is crucial to assess the stability of flood defense structures like levees under extreme flood conditions. This study focuses on the time-dependent probabilistic assessment of embankment slope stability when subjected to rapid water level drops. We integrate seepage analysis results from finite element analysis with slope stability analysis and employ Monte Carlo simulations to investigate the time-dependent behavior of the slope during rapid drawdown. The resulting probability of failure is used to develop fragility curves for the levee slope. Notably, the probability of slope failure remains low up to a specific water level, sharply increasing beyond that threshold. Furthermore, the fragility curves are strongly influenced by the rate of drawdown, which is determined through hydraulic analysis based on flood scenarios. Climate change has a significant impact on the stability of the water-side slope of the embankment due to water level fluctuations.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.9
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• pp.28-35
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• 1999

In this study, investigation of transient knock characteristics in a spark-ignition engine has been carried out. The universal knock threshold values were found by a DFDD method and a NSDBP method which is a non-dimensional version of the SDBP method. Also modified NSDBP method could be used for transient knock detection. In a commercial ECU , spark timing was retarded from the steady -state spark timing during rapid throttle opening to avoid uncomfortable feeling and knock. Knock usually occurred just after the start of rapid throttle opening when spark timing was set, as values for the steady state condition. We found that air/fuel ratio deeply involved with the knock during transient condition. Due to the difference of initial heat release rate, knock occurred more easily at rich air/fuel ratio than at lean air/fuel ratio.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.339-343
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• 2000

Rapid prototyping for welding and milling is a hybrid approach that makes use of welding as additive and conventional milling as subtractive technique. For two years this concept has been used to verify manufacturing mold and mechanical parts successfully. In latest new fabrication methods. For example, manufacturing mold for two sort of materials and shell fabrication, have been applied to the concept in KIST. This methods will be an alternative proposal in rapid prototyping. Metal deposition for welding causes the part to deform. It is a handicap in our proceeding. To overcome this problem, in this paper, we represent an optimal welding path for FEM analysis. Eight paths are tried to this and the value of deformation is average and standard deviation in four points'. Then we can compare with eight cases and select the optimal path.

• International Journal of Highway Engineering
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• v.16 no.4
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• pp.11-19
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• 2014

PURPOSES: This study is to suggest the improvement for bus rapid transit system in Seoul METHODS: The maintenance cost for bus lane damages and plastic deformations are increased by bus passing speed, heavy bus weight, and climate change (localized torrential downpour, subtropical climate) and the accident risk has been increased. RESULTS: Recent analysis of pavement damage indicates that bus lane damage caused by heavy weight is overwhelming and it is urgent to prepare countermeasures. CONCLUSIONS : Pavement data of bus rapid transit system, bus transit numbers and pavement damage elements were analyzed. By analyzing pavement maintenance, design and construction, the countermeasures for the improvement of bus lane pavement and effective maintenance were suggested.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11a
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• pp.504-511
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• 2001

In this research, we developed a computer program that designs a centrifugal impeller and diffuser, and predicts the far-field noise from the impeller. To design the impeller optimally, the TEIS model, which was originally developed by Japkise(1985), and the mean-line analysis are combined to predict the performance and design the optimal impeller simultaneously. The geometric configurations are provided by a GUI software (iDesignComp). The noise from impeller can be computed by the rapid loading procedure, which generates a surface between two blades and calculates the pressure distributions on the suction and pressure sides. The steady loading noise is computed by the rotating dipole source distribution via Ffowcs Williams & Hawkings equation.

• Journal of Korea Foundry Society
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• v.2 no.1
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• pp.12-18
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• 1982

The present investigation was made to abtain a fine distribution of Pb Particles in AL - Pb binary alloys , which have a broad miscibility gap and large specific difference, by means of rapid Cooling of the molten alloys. Al-2.4% Pb, Al-5.5wt% Pb and Al-8.0wt % Pb alloy were used. The rapid cooling operation was performed by free falling of homogeneous liquid Al-Ph alloys into the water-cooled copper mold, and thermal analysis was made. Microstructures were observed, and variations of size and number of Pb particles were analysicle analyzer. By the result of examination with the varing cooling rates 100 to $210^{\circ}C/sec$ fine distributions of Pb particles were obtained with high cooling rate. Under same cooling condition, the best rapid cooling effect was recognized in Al-5.5wt% Pb alloy.