• Journal of the Korea Convergence Society
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• v.10 no.9
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• pp.161-166
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• 2019

This study examines the flows near the different side mirrors by analyzing the flow due to air resistance at A, B and C models of automotive side mirrors. Model A is a square-shaped side-mirror. Model B is a triangular side-mirror and model C is an oval-shaped side-mirror. The air resistance of the side-mirror while driving is reduced and the automotive power can be reduced by changing the design of automotive side-mirror. As analysis result, as the pressure of air resistance against side mirror becomes larger, it can be seen that the air flow rate becomes great. Therefore, it can be estimated that the smaller the pressure of air resistance, the smaller the flow rate and the better the air flow. Therefore, it can be acknowledged that model B is the best model. As the design data of the automotive side mirror obtained on the basis of this study result are utilized, the esthetic sense can be shown while driving a car at real life.

• ETRI Journal
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• v.29 no.6
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• pp.808-810
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• 2007

We demonstrate 10 Gbps optical signal transmission via long-range surface plasmon polaritons (LR-SPPs) in a very thin metal strip-guided geometry. The LR-SPP waveguide was fabricated as a 14 nm thick, 2.5 ${\mu}m$ wide, and 4 cm long gold strip embedded in a polymer and pigtailed with single-mode fibers. The total insertion loss of 16 dB was achieved at a wavelength of 1.55 ${\mu}m$ as a carrier wave. In a 10 Gbps optical signal transmission experiment, the LR-SPP waveguide exhibits an excellent eye opening and a 2.2 dB power penalty at $10^{-12}$ bit error rate. We confirm, for the first time, that LR-SPPs can efficiently transfer data signals as well as the carrier light.

• 한국전산유체공학회:학술대회논문집
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• 2002.10a
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• pp.95-102
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• 2002

Studies of the numerical characteristics of implicit upwind schemes, such as upwind ADI, Line Gauss-Seidel(LGS) and Point Gauss-Seidel(LU) algorithms, for preconditioned Navier-Stokes equations ate performed. All the algorithms are expressed in approximate factorization form and Von Neumann stability analysis and convergence studies are made. Preconditioning is applied for efficient convergence at low Mach numbers and low Reynolds numbers. For high aspect ratio computations, the ADI and LGS algorithms show efficient and uniform convergence up to moderate aspect ratio if we adopt viscous preconditioning based on min- CFL/max- VNN time-step definition. The LU algorithm, on the other hand, shows serious deterioration in convergence rate as the grid aspect ratio increases. Computations for practical applications also verify these results.

• 한국전산유체공학회:학술대회논문집
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• 2003.08a
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• pp.49-55
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• 2003

A comprehensive study has been made for the investigation of the convergence characteristics of the LU scheme for the Euler equations using von Neumann stability analysis. The stability results indicate that the convergence rate is governed by a specific parameter combination. Based on this insight it is shown that the LU scheme will not suffer convergence deterioration at any grid aspect ration if the local time step is defined using appropriate parameter combination. The numerical results demonstrate that this time step definition gives uniform convergence for grid aspect ratios from one to $1\times10^4$.

• Journal of the Korea Convergence Society
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• v.6 no.6
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• pp.247-253
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• 2015

The purpose of this convergence study was to analysis the current status of the cancer screening and background healthcare systems in Korea and Japan. First, Cancer Screening Program is coordinated well with National Health Insurance Service(NHIS) under a unified insurer system in Korea. But in Japan, there are over 3,500 insurer and coordinating a comprehensive strategy for cancer screening promotion has been very difficult. Second, Rate of cancer screening is influenced by public healthcare system. In Korea public healthcare does not cover a wide rage of services. Almost free cancer screening provides high incentive to participation. It is very important to understand the impacts of each healthcare system when designing an efficient cancer screening system.

• ETRI Journal
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• v.33 no.2
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• pp.145-154
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• 2011

We present a novel video codec for supporting entertainment-quality video. It has new coding tools such as an intra prediction with offset, integer sine transform, and enhanced block-based adaptive loop filter. These tools are used adaptively in the processing of intra prediction, transform, and loop filtering. In our experiments, the proposed codec achieved an average reduction of 13.35% in BD-rate relative to H.264/AVC for 720p sequences.

• ETRI Journal
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• v.30 no.6
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• pp.859-861
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• 2008

This letter proposes a conditional access system (CAS) suitable for use in terrestrial digital multimedia broadcasting (T-DMB), based on an effective multiplexing method to provide encrypted T-DMB services. Specifically, the proposed multiplexing method for a CAS is designed to reduce the additional bit rate while assuring easy access to the designated encrypted services. Finally, the performance of the implemented CAS is confirmed through implementation and a broadcasting experiment under various service environments.

• Journal of the Korea Convergence Society
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• v.11 no.1
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• pp.77-82
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• 2020

In order to analyze the positive rate of hepatitis B surface antibody by age before and after hepatitis B vaccination, 13,855 serum specimens who were referred for the hepatitis B surface antibody test at the General Hospital of Jeju Hospital were examined by CMIA method. The positive rate of HBs Ab was 5,176 (37.36%). The positive rate according to gender was 40.13% for female and 34.77% for male. The age group with the highest HBs Ab average was in their 40's (399.86 mIU/mL), while the lowest age group was in the 90's (211.50 mIU/mL). It is remarkable that the age group with the highest HBs Ab positive rate is in the 30's, and that teenagers (age group of 10-20 years) had the lowest positive rate. Especially 15, 18, 19 years old was statistically significant. Consideration should be given to determining the titer of vaccination and to clarify the timing of vaccination.

• Journal of Convergence for Information Technology
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• v.10 no.1
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• pp.75-81
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• 2020

This study analyzed the annual difference of firm's book income, taxable income and BTD that before and after the 2009 corporate tax rate cut and 2018 corporate tax rate increase. ANOVA analysis was performed for each item by year, and post hoc was performed after homogeneity test of variance. The research results are as follows. First, the book income at corporate tax rate cut was higher than taxable income, and BTD in 2008 was significantly different from other years. Second, the book income at corporate tax rate increase was less than taxable income, and BTD in 2017 was also significantly different from other years. In other words, the firm is performing appropriate profit adjustments to reduce of tax burden when the corporate tax rate changes. Because of this, the BTD in the year immediately before the corporate tax rate change is different from other years.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.4_2
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• pp.615-621
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• 2023

In this study, flow analysis of single, double, and triple filter systems of cylindrical structures was performed to analyze the flow characteristics of each filter. As a result of the flow analysis of the filter system, the number of filters and the pressure drop rate tend to be proportional to each other. It was found that the area passing through the inside of the filter had almost the same pressure. The maximum pressure drop rate of the triple filter system was about 14.9% for the forward-flow and about 12.4% for the reverse-flow. It was determined that the performance of the filter was stable within 20% of the allowable pressure drop rate of the filter system, which is the standard presented to the Korea Water Technology Certification Institute(KWTCI). In the future, a study on the decompression characteristics of the filter system according to the effect of the arrangement interval and filter density of the triple filter will be conducted.