• Journal of Korea Multimedia Society
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• v.19 no.6
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• pp.990-1002
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• 2016

In this paper, we propose a new compression method for the edge image by analyzing the characteristics and the distribution of pixel values of the edge image. The pixel values of the edge image have the Gaussian distribution around '0', and most of the pixel values are `0`. By these analyses we suggest the Zero-Based codec that expresses all values in a CU by a single bit flag. Also, in order to reduce the computational complexity of the proposed codec, the block partition and the intra-prediction techniques are proposed by using edge information like the number of each edge direction, the distribution and the amplitude of a major edge direction in the CU. Experimental results show that the proposed codec leads to a slighter distortion in Y domain than that of HEVC, but has far faster processing speed up to 53 times while it maintains the similar image quality compared to HEVC.

• Journal of Distribution Science
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• v.18 no.6
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• pp.47-55
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• 2020

Purpose: The issue of access to credit for private enterprises has been given an increased amount of attention given their crucial role in fueling economic growth. Vietnamese small and medium-sized businesses, however, face many obstacles in accessing financing for profitable investment opportunities, with up to 70% unable to access or obtain bank loans. This paper aims to address the factors affecting the credit accessibility of Vietnamese enterprises, and provide further insights of this issue under the new context of Basel II. Research design, data and methodology: We adopt a pooled sections approach to construct a sample of 155 firm observations before and after the implementation of Basel II accord in Vietnam and employing binary logistic regression and interaction terms for data analysis. Results: We find that firm characteristics (export participation, female ownership) and proxies for bank-borrower relationship (deposit, overdraft facility) have significant and positive effects on firm's access to credit. Notably, the sign of interaction coefficient shows that the implementation of Basel II tends to benefit small-sized firms in terms of credit accessibility. Conclusions: The finding further emphasizes the important role of relationship lending in Vietnam's credit market, which is even more critical for small firms when Basel II is universally applied as the new banking standards in the coming years.

• The KIPS Transactions:PartC
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• v.9C no.3
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• pp.331-336
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• 2002

In this paper, we propose a new distribution and renewal scheme for a group key suitable for secure mobile communications based on identification protocol, in which all members of the group can reshare the new group common key except revoked members by using a key distribution center (a trusted center). The security of this scheme is based on the difficulty of the discrete logarithm problem. The proposed scheme can be appropriately managed in case that terminal's capability of storage and computing power is relatively small and more than one caller are revoked. It also renews a group key easily when the center changes this key intervally for security.

• Progress in Superconductivity and Cryogenics
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• v.5 no.2
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• pp.41-45
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• 2003

Resistance distribution in thin film type SFCL elements of different shunt layer thickness was investigated. The 300 nm thick film of 2 inch diameter was coated with a gold layer and patterned into 2 mm wide meander lines. The shunt layer thickness was varied by ion milling the shunt layer with Ar ions, and also by having the shunt layer grown in different thickness. The SFCL element was subjected to simulated AC fault current for measurements. It was immersed in liquid nitrogenduring the experiment. The resistance distribution was not affected by the shunt layer thickness at applied voltages that brought the temperature of the elements to similar values. This result could be explained with the concept of heat transfer from the film to the surroundings. The resistance distribution was independent of the shunt layer thickness because thick sapphire substrates of high thermal conductivity dominated the thermal conductance of the elements.

• Journal of Positioning, Navigation, and Timing
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• v.3 no.2
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• pp.83-90
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• 2014

In this study, to improve an existing ground-wave based time broadcasting system, a study that predicts the field distribution and field strength of the transmitted signal of a new ground-wave based time broadcasting system was performed. The prediction area was assumed to be the Korean peninsula; and to reflect the mountainous terrain of the Korean peninsula in the prediction of the variations of field distribution and field strength, a new prediction method based on the Monteath model was proposed and utilized. As field distribution changes depending on the position of a transmitter station, potential sites for the transmitter station were selected considering the geographical characteristics. In this regard, the ground conductivity information of North Korea cannot be obtained, and thus, the ground conductivity of the North Korean region was reflected considering the geological characteristics of South Korea and North Korea. Based on this, the variations of field distribution and field strength were predicted by setting the Korean peninsula as the prediction area, and the prediction results depending on the position of the transmitter station were discussed.

• Journal of Hydrogen and New Energy
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• v.28 no.6
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• pp.704-711
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• 2017

Korea, which has a high dependency on energy imports, is greatly affected by fluctuations in international oil prices. In order to offset these effects, various policies such as 'diversification of energy sources' and 'energy mix' are being pursued. Renewable Fuel Standard (RFS) is a policy promoted for this purpose, and a compulsory mixing system is applied only to the diesel. In order to reduce dependence on fossil fuels in various countries, they are concentrating on the dissemination of bio-alcohol as well as bio-diesel, and commercialization through various verification. In this study, evaluation of domestic materials and vehicles was carried out to promote domestic bio alcohol fuel. We analyzed the fuel characteristics of domestic quality standard items by mixing them with gasoline of automobile at a certain mixing ratio (0%, 3%, 6%, and 10%).

• Journal of Hydrogen and New Energy
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• v.28 no.5
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• pp.584-599
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• 2017

Biodiesel is renewable, eco-friendly, clean burning diesel replacement that is consisted of short chain alkyl ester. Biodiesel is derived from the transesterification of vegetables oils or animal fats with alcohol. The process has some technical problems that must be resolved to reduce the high operation cost. Eco-friendly physical technologies by using microwave have successfully improved the transesterification for biodiesel production. This paper attempts to extensively review microwave-assisted technology for biodiesel production. Additionally, different types of catalyst for biodiesel production have been summarized. It is concluded that the microwave-assisted technique improves the reaction rate significantly in comparison with conventional methods. Therefore it can be a suitable method of reducing the reaction time and can also decreases the cost of biodiesel production.

• Journal of Arbitration Studies
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• v.28 no.2
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• pp.165-178
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• 2018

Exchanging information with a person without credentials over the Internet does not pose any problems. A decentralized system based on blockchain technology enables the user to exchange new value(currency) with other uncredited users. The blockchain technology creates a new paradigm in which the distribution system can be founded on trust. Various applied distribution systems are being developed based on this paradigm. This study analyzed the problems between an institute's grading system and the central administration system. The limitations of an institute's current central management system were presented through actual cases. To improve the problem, a decentralized system based on block chain technology was presented in order to overcome the fundamental limitations by utilizing blockchain technology, peer-to-peer network, and the distribution system. In the central system, a malicious moderator could create a malicious edit that becomes the cause of a dispute, but in a decentralized system, a problem cannot be created even if there were to be a malicious moderator. However, it is difficult for a single college institute to create a distribution system in order to actualize an effective system. Comparatively, it would be possible to create a decentralized system in which all educational institutes in Korea (elementary schools, middle schools, high schools, colleges) took part in. The application of a decentralized system would improve the public transparency and reliability of educational institutes.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.3
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• pp.69-77
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• 2006

This paper presents the service restoration in electric power distribution systems. The aim of the service restoration is to control an emergency taken place in distribution systems and to restore out-of service areas as soon as possible when a fault occurs in distribution systems. For this reason, new service restoration strategies in multi-outage area are suggested in this paper. The suggested algorithm consist of two schemes. One is an individual restoration scheme, the other is an integrated restoration scheme. The former determines a restoration order of outage areas based on a restoration index. Unless the former scheme can generate a feasible restoration plan, the latter one will try to find out a new configuration without an overloaded section through tie exchange method.

• Nuclear Engineering and Technology
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• v.49 no.5
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• pp.905-913
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• 2017

Advanced reactor designs often feature longer operating cycles between refueling and new concepts of operation beyond traditional baseload electricity production. Owing to this increased complexity, traditional proportional-integral control may not be sufficient across all potential operating regimes. The prototypical advanced reactor (PAR) design features two independent reactor modules, each connected to a single dedicated steam generator that feeds a common balance of plant for electricity generation and process heat applications. In the current research, the PAR is expected to operate in a load-following manner to produce electricity to meet grid demand over a 24-hour period. Over the operational lifetime of the PAR system, primary and intermediate sodium pumps are expected to degrade in performance. The independent operation of the two reactor modules in the PAR may allow the system to continue operating under degraded pump performance by shifting the power production between reactor modules in order to meet overall load demands. This paper proposes a Takagi-Sugeno (T-S) fuzzy logic-based power distribution system. Two T-S fuzzy power distribution controllers have been designed and tested. Simulation shows that the devised T-S fuzzy controllers provide improved performance over traditional controls during daily load-following operation under different levels of pump degradation.