• Journal of Advanced Navigation Technology
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• v.24 no.4
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• pp.299-304
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• 2020

This paper proposes the design of circular sector shaped power divider-combiner with a planar structure. This structure can be constructed in series, and due to the circular sector shape, it is possible to simplify circuit configuration and improve the amplitude and phase balanced characteristics of the output. It has a simple input matching circuit and an RC parallel circuit was inserted between the output ports to improve the reflection coefficient and isolation of the output. Since the designed divider-combiner are structurally designed in a symmetrical shape of a sector, even if the output ports are composed of two or four output ports, they have excellent characteristics with an amplitude balance of ± 0.1 dB and a phase balance of ± 1o between outputs. To prove these characteristics, it was confirmed that the characteristics of the planar power divider-combiner fabricated at an operating frequency of 2 GHz are in good agreement with the simulation.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.11
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• pp.2181-2188
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• 1992

Two-dimensional natural convection within a circular trapezoidal cavity with parallel cylindrical top and bottom walls at different temperatures and two adiabatic side walls has been solved by finite-difference methods. This study has been conducted to evaluate the effects of aspect ratio and inclination in the natural convection for various Rayleigh numbers. The minimum average Nusselt number occurs at the point of transition from a conductive heat transfer to a convective heat transfer. Numerical results are compared to experimental results with qualitatively good agreement.

• Journal of Korean Society of Forest Science
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• v.104 no.1
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• pp.60-66
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• 2015

This study was conducted to determine the effects of seed storage method ($-20^{\circ}C$, $2^{\circ}C$ dry, $2^{\circ}C$ wet 30 days, $2^{\circ}C$ wet 60 days, stratification and room temperature) and shading treatment(control, 50%, 80%) on seed germination, seedling growth of endangered species, Iris dichotoma and Iris setosa. As a result, seed germination rate of I. dichotoma was the highest at 75% when seed were stored at $2^{\circ}C$ wet 60 days and then sown under non-shading condition. The seed of I. dichotoma belong to intermediate seed. Seed germination rate of I. setosa was the highest at 95% when seed were stored at $2^{\circ}C$ wet 60 days and then sown under 80% shading condition. The seed of I. setosa belong to recalcitrant seed. Seedlings of I. dichotoma and I. setosa showed not only the best seedling quality but also seedling vigor index in seed stored at $2^{\circ}C$ wet 60 days under non-shading condition, with the growth characteristics of plant height (6.4, 7.2 cm), number of leaves (3, 4), leaf width (4.6, 3.2 mm), leaf length (5.7, 6.8 cm), fresh weight (aerial/root part; 144/260, 97/153 mg), dry weight (aerial/root; 31/20, 17/17 mg) and seedling vigor index and modified seedling vigor index (13,895/9,479, 13,256/8,668). In this research, I. dichotoma and I. setosa seed were stored at $2^{\circ}C$ wet 60 days, and then sown in non-shading condition, seed germination rate was more than 75%, 90%, respectively, and production of superior quality seedlings.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.3
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• pp.337-345
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• 2018

The purpose of this study is to analyze the relationship between the characteristics of Korean family firms and the impact of debt financing. The analysis period was 10 years from 2004 to 2013, and the sample consisted of 4,008 non-financial firms listed on the Korea Exchange. For the analysis, the unbalanced panel data with time - series, cross - section data were formed and analyzed using panel data regression analysis. The results are as follows. First, Korean family firms use relatively less debt than non - family firms. It can be understood that family firms in which the dominant family owns and dominates the corporation are less likely to increase their debt because the agent problem is alleviated and the need for the control effect of Jensen (1986) is lowered. Second, in the verification of the packing order theory using the model proposed by Shyam-Sunder and Myers (1999), family firms have higher compliance with the packing order theory than non-family firms do. When financing is needed, debt is preferred over equity issuance. However, for Korean family firms, 24.38% of the deficit funds are financed through the issuance of net debt, which is relatively low compared to the 75% shown in the analysis of Shyam-Sunder and Myers (1999). These results reveal the limit to the strong claim that the Korean family firms follow the packing order theory.

• Proceedings of KHEA Conference
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• 2003.10a
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• pp.142-142
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• 2003

• Proceedings of the Zoological Society Korea Conference
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• 1996.04a
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• pp.52.1-52
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• 1996

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.3
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• pp.316-322
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• 2002

The Orthogonal Frequency Division Multiplexing(OFDM) is a special case of multicarrier transmission, where a single data stream is divided into many subcarriers and transferred in a parallel way. It reduces the necessary bandwidth using the orthogonality between the subcarriers. Therefore it requires the transmission channel which has stable characteristic. When the delay spread of the channel exceed the guard interval, then the orthogonality of the subcarriers cannot maintain and as a result the system performance degrade. In this paper, the XCP-OFDM(OFDM using cross-handed Circular Polarization) system is newly proposed. This system divides the channel in order to eliminate the overlapping of subcarrier's spectrum by using cross-handed circular polarization. Therefore, the proposed XCP-OFDM system can improve the performance without increasing the guard interval. Both theoretical analysis and simulation results are described.

• The Journal of shipping and logistics
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• v.34 no.4
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• pp.615-635
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• 2018

Using data from 2008 to 2017, this study analyzed the financial characteristics of offshore freight shipping companies in Korea, categorized by vessel type, and their impact on business performance. The analysis showed an upward trend in the overall debt ratio of offshore freight transport companies and differences in the financial characteristics of each vessel type as well as the major factors affecting business performance. In particular, the significant factors affecting the ROA performance of the business are the size of business and debt ratio in the LPG line; the growth rate in the bulk line; the size of business, debt ratio, and year in the general freight line; and the size of business, growth rate, entertainment expense rate, debt ratio, and year in the full container line. Therefore, each shipping company needs to recognize differences in key financial factors affecting its performance based on vessel type, implement proactive measures, and diversify its vessel portfolio.

• Journal of Korea Entertainment Industry Association
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• v.14 no.5
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• pp.87-102
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• 2020

The purpose of this study was to develop regional dance contents in order to receive attention from the region and re-illuminate the peacock fan, the intangible cultural property of Seocheon, Chungnam, which has been preserved in history and has been preserved in the face of rapid urbanization and modernization. The representative four series are composed of one-person dance, two-person dance, military dance, and creative dance. The titles of each piece are basic dance , male and female love dance , military dance , and finally Korean creative dance . The commonality of the four series is the traditional dance using peacock fan, and each dance showed unique emotion and atmosphere through different themes and music, costumes, and stages. It was found that the development of regional dance contents re-created reflecting the characteristics of regional cultural heritage should create an environment that can be steadily revitalized through modernization. Through this study, it was found that the intangible cultural properties, which are our traditional cultural resources, have unlimited potential to contribute to enhancing regional and national competitiveness along with the growth potential of regional differentiation. Through such research, if existing cultural resources are preserved for globalization and produced as contents that can be easily accessed by the public, various contents besides regional dance using regional unique culture can be developed and utilized.

• KDI Journal of Economic Policy
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• v.32 no.4
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• pp.1-34
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• 2010

We conduct a comprehensive risk analysis of household debt in Korea for the first time using the whole sample credit bureau (CB) data of 2.2 million individual debtors. After analysing debt service capacity profiles of debtor groups classified by the borrower characteristics such as income, age, occupation, credit scoring, and the type of creditor business companies, we investigate the impact of interest rate and income changes on debt service-to-income ratios (DTIs) and default rates of respective debtor groups. Empirical results indicate that debt service burdens are relatively high for low income wage earners, high income self-employed, low income capital and card loan holders, and high income mutual savings loan holders. We also find that debtors from multiple financial companies are particularly weak in their debt service capacity. The scenario analysis indicates that financial companies, with the current level of capital buffers, may be able to absorb negative consequences arising from the increase in DTIs and loan default rates if the interest rate and income changes remain modest. However, the negative consequences may fall disproportionately on non-bank financial companies such as capital, credit card, and mutual savings banks, whose debtors' DTIs are already high. We also find that the refinancing risk of household debt is relatively high in Korea as more than half of household mortgage debts are bullet loans. As the DTIs of mortgage loan holders are already high, under the current DTI regulation, mortgage loans may not be readily refinanced especially when the interest rate rises. Disruptions in mortgage loan refinancing may put downward pressure on housing prices, which may in turn magnify refinancing risk under the current loan-to-value (LTV) regulation. Overall our analysis suggests that, for more effective monitoring of household debt risk, it is necessary to combine existing surveillance schemes based on macro aggregate indicators with more comprehensive and detailed risk analyses based on micro individual data.