• Journal of the Korean Society of Propulsion Engineers
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• v.14 no.4
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• pp.32-38
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• 2010

Heat transfer coefficients in a dimpled channel, a ribbed channel, and a rip-dimple compound channel were measured by the transient liquid crystal technique. The channel aspect ratio, the rib height, the rip pitch, and the rib angle were 4:1, 6 mm, 60 mm and $60^{\circ}$, respectively. The dimple diameter and the center-to-center distance were 6mm and 7.2 mm, respectively, and the Reynolds number range was 30,000-50,000. Results showed that the heat transfer coefficients were increased by the angled rib. For the dimple-rib compound cooling cases, the heat transfer coefficients were further augmented and the thermal performance factor for the case was the highest.

• Solar Energy
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• v.14 no.2
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• pp.61-74
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• 1994

Since the atmospheric clearness index is main factor for evaluating atmosphere circumstance, it is necessary to estimate its characteristics all over the cities in Korea. We have began collecting clearness index data since 1982 at 16 different cities and considerable effort has been made for constructing a standard value from measured data at each city. The new clearness index data will be extensively used by evaluating atmospheric circumstance analysies as well as by solar application system designer or users. From the results, we can conclude that 1) Yearly mean 63% of the atmospheric clearness index was evaluated for clear day all veer 16 cities in Korea. 2) Atmospheric clearness index of spring and summer were 63% and 64% and for fall and winter their values wre 61% and 59% respectively. So, spring and summer were higher, and fall and winter were lower then the yearly value. 3) A significant difference of atomospheric clearness index is observed between $1982{\sim}1987$ and $1988{\sim}1993$ through 16 different cities in Korea.

• Journal of the Korea Society of Computer and Information
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• v.11 no.4 s.42
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• pp.77-85
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• 2006

There is the spatial correlation of the video sequence between the motion vector of current blocks. In this paper, we propose the enhanced fast block matching algorithm using the spatial correlation of the video sequence and the center-biased properly of motion vectors. The proposed algorithm determines an exact motion vector using the predicted motion vector from the adjacent macro blocks of the current frame and the Cross-Hexagonal search pattern. From the of experimental results, we can see that our proposed algorithm outperforms both the prediction search algorithm (NNS) and the fast block matching algorithm (CHS) in terms of the search speed and the coded video's quality. Using our algorithm, we can improve the search speed by up to $0.1{\sim}38%$ and also diminish the PSNR (Peak Signal Noise Ratio) by at nst $0.05{\sim}2.5dB$, thereby improving the video qualify.

• Journal of Digital Convergence
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• v.19 no.12
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• pp.641-648
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• 2021

This study examined the effects of irrational beliefs, impulsivity and happiness on problem gambling of Korean and Australian college students. Data were collected from 581 college students of Korea, and 100 college students of Cairns of Australia. As a result, The overall mean of the CPGI was significantly different between Koreans and Australians (t=-29.828**). As for classification of gamblers by sub-type of CPGI, the number of problem gamblers in Australians was 7.0% compared to 5.3% for Koreans, showing a significant difference. In Multiple regression analyses, irrational beliefs, happiness, and the frequency of gambling significantly predicted problem gambling of Koreans (R2 = 0.175 F = 23.441, p < .001). On the other hands, irrational beliefs and the frequency of gambling significantly predicted problem gambling of Australians(R2 = 0.368, F = 10.844, p < .001). Through this study, it was found that the factors affecting the problem gamblers of Korean and Australian are different. It is required to continue further education on gambling among young adults of Korea and Australia.

• Environmental and Resource Economics Review
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• v.30 no.3
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• pp.435-469
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• 2021

The main purpose of this study is to identify the determinants of electricity import and export in 26 European Union countries using the Spatial durbin model(SDM). In particular, we would like to mainly explain it based on the amount of power generated by each energy source. Not just the usual way of constructing a weighting matrix based on contiguity, we adopt a weighting method based on the proportion of trade among countries with connected electricity systems. Moreover, the electricity systems of European countries are directly and indirectly connected, which is reflected in the weighting matrix. According to the results, nuclear power has a positive effect on exports and a negative effect on imports, and an increase in wind and solar power has a positive effect on both exports and imports by increasing power system instability. While Korea is unable to trade electricity due to geopolitical conditions, the results of this study are expected to provide implications for energy policies.

• Journal of Korea Port Economic Association
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• v.37 no.2
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• pp.119-131
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• 2021

Energy is an essential element in economic activity and people's lives, an important resource used by various industries, and the financialization of commodity markets has led to the growing importance of crude oil turning into the same asset as other assets. Accordingly, studies analyzing the correlation between energy prices and investor sentiment explain that investor sentiment affects oil prices through economic factors and speculation. In this study, we wanted to analyze whether the impact of the most representative changes in oil prices affects investor decision making, affecting investor sentiment, and applying wavelet consistency analysis to determine how energy prices relate to investor sentiment. Studies show that policies should be focused on policy and market changes because energy prices differ by time scale and investment sentiment should be more influential in the long term than in the short term.

• Journal of Korea Port Economic Association
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• v.36 no.4
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• pp.75-92
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• 2020

Currently, shipping and port industries are mainly concerned with securing a competitive advantage through scale expansion. Reflecting this trend, domestic ports and container terminals also emphasize efficiency through dock integration. This study identified factors that facilitate cooperation between container terminal operators, as the smallest unit of port operation, and analyzed their effects. These factors included sharing of resources, clarity of purpose, mutual trust, and influence of government policies. In addition, factors related to effectiveness included operational effectiveness of the terminal, improved service to shippers and shipping companies, and bargaining power with the government. The empirical analysis revealed that, among the factors that facilitate cooperation, sharing and purpose affected operational effectiveness, while sharing of resources affected service improvement of shippers and shipping companies. Finally, policy factors affected port bargaining power.

• International Area Studies Review
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• v.22 no.2
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• pp.93-119
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• 2018

During the period from 2004 to 2013, the China's automobile consumer protection policy-making reflected interest articulation and aggregation among consumers, manufacturers, car dealership and repair companies. In particular, consumers has succeeded in articulating their interests in spite of their dispersed situation by making the efforts to present regulation's revision agenda through the China Consumers Association. And the car dealers put the right to blame the car manufacturers for unexpected vehicle defects into the final regulation through the China Automobile Distribution Association. Finally, due to the active interest articulation of automobile companies, policy making process was delayed or policies that were expected to benefit consumers were promoted to some extend. Therefore, it can be seen that there is a limit to define state-society relations in China simply as state corporatism, and rather it is more important to understand state-society relations in China as between state corporatism and societal corporatism including bottom-up interest articulations and aggregations and policy modification activities of various private or societal organizations.

• International Area Studies Review
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• v.14 no.3
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• pp.502-523
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• 2010

A federal system speaks for a political system that the principle of the common sovereignty among the local governments is applied. The basic purpose of the system is to make institutional devices capable of striving for the mutual cooperation in a greater political unit, reflecting a minority race's right and demand by decentralizing a state authority into the individual region. The basic purpose for formation of a federal system is realized when a form for the supplement of political elite personnels has a autonomous nature by the subject of a federal structure. During from B.Yeltsin to V.Putin, a form for the supplement of political elite personnels into the local governments has changed by a political purpose of a central government, In company with this change, the character of federalism in Russia has been also changed. Accordingly, this study has treated a subject about how the political elite personnels of local assembly men, governors of a state, assemblymen of both Houses, and the president of Russia are suppled, and also how such a form for the supplement of political elite personnels has changed the character of federalism in Russia.

• International Area Studies Review
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• v.15 no.2
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• pp.51-76
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• 2011

Since Japanese government took reformative measures of public investment in the period of 2000s, this paper investigates how the economic effects of public investments has improved in the period of 2000s. The empirical findings do not show that the output elasticity with respect to public capital has been higher in the 2000s than that of 1990s. Rather, some output elasticity estimates for 2000s has lowered after the advent of year 2000. In addition, the impact of public capital on the productivity of private capital has not improved in the 2000s compared with that of 1990s in Japan. Another major finding shows that the crowding-out effect of public investment has been stronger in the 2000s than before. Those findings imply that the reforms done by Japanese government in the 2000s regarding public investment do not spread out into the private aggregate production and investment.