• Convergence Security Journal
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• v.22 no.4
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• pp.25-34
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• 2022

This paper proposes a secret sharing based fast node authentication technique applicable to Flying Ad-Hoc Network (FANET) that can be used to construct self-organized communication network in multi drones and drone squadrons operations. Before deployment, each node stores an exponential share, exponential secret and a portion of PUF CRP table. After being deployed in the field, in the early-stage of network formation, each node broadcasts its ID, exponential share and a hash value of PUF Response and pseudo-random number. Then each node performs a reconstruction of the exponential secret using the exponential shares transmitted from neighboring nodes. When the exponential secret is reconstructed, simultaneous authentication is completed for all nodes that have transmitted the exponential share used in the reconstruction. A node that transmits an incorrect exponential share to disturb the reconstruction of the exponential secret during the authentication process can be detected before performing the reconstruction through the verification of the hash value, and will be excluded from the reconstruction.

• The Journal of the Korea Contents Association
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• v.22 no.5
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• pp.81-96
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• 2022

Covid-19 calls for minimizing gatherings of people in spaces such as offices. Organizations are encouraging information-sharing activities among employees by using online platform technology. Recently, Organizations are supporting their work using the metaverse. This study confirms the effect of metaverse presence on the intention to share knowledge by forming the intrinsic motivation of the employees and the moderating effect of the individual's digital technological competence. We presented research hypotheses through previous studies such as virtual reality and tested the hypotheses using 309 samples obtained through surveys. As a result, the social, tele, and self presence of the metaverse increased organizational-related intrinsic motivation(organizational identification, value congruence) and had a positive effect on the intention to share knowledge. In addition, digital technological competence moderated the relationship between value congruence and intention to share knowledge. This study suggests the importance of strategies to enhance the presence of metaverse for organizations to increase work productivity by using metaverse and the need to support individual digital competence reinforcement.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.6D
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• pp.935-943
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• 2006

Key factors affecting the mode share of Soul metro are investigated. The log-regression model, which can describe the elasticity of the factors with ease, is established rather than the conventional mode choice model is used. The log-regression model requires lower level of data availability for calibration and identifies the impact of the factors on mode share straightforwardly. As a result, it is found that the main reasons why the current mode share of railway is low are due to several problems such as winding lines, inconvenient transfers and unnecessary bypasses. The calibrated model is adopted to evaluate the network reshuffling alternatives. The network reshuffling is to rearrange the existing inefficient railway lines that have frequent transfers and many winding segments. The proposed network reshuffling, which includes straightening winding lines and changing grade separated transfers into cross-platform transfers, turned out to be a good measure to tackle the problems.

• Korea Trade Review
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• v.47 no.6
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• pp.247-267
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• 2022

Since the Korea-Vietnam FTA was signed in 2015, trade between the two countries has increased rapidly, accounting for 6.8% of Vietnam's exports and 17.9% of its imports in 2020. The two countries show differences in import and export items. Vietnam has a high export ratio of agri-food products or products with the low-middle level of technology, while Korea has a high export ratio of products with the upper-middle level. The purpose of this study is to present implications by analyzing changes in trade competitiveness between Vietnam and Korea by technology level (2002-2020). For this purpose, statistics from UN Comtrade were used, and methodologies such as market share, Export Market Share (EMS), Trade Specialization Index (TSI), Intra-Industrial Trade Index (IIT), Revealed Comparative Advantage (RCA), and BCG Matrix were used. The results of the study are as follows. First, when looking at Vietnam's trade structure with South Korea by technology level, it was analyzed that the trade deficit widened as it showed a competitive disadvantage in high-tech, ICT, middle- and low-level technology items, excluding low-end technology items. Second, in terms of market share, the market share of Vietnamese products in the Korean market is continuously increasing, while the Korean market share in Vietnam is gradually decreasing from 2017. Third, Vietnam's export competitiveness to Korea by technology level shows that low-level technologies are competitive, but they are inferior in competitiveness in all other technology level, and especially in areas with high technology level, the level of inferiority is high. In conclusion, the trade relationship between Vietnam and Korea has maintained a mutually complementary rather than competitive relationship, which is expected to continue in the future.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.30B no.1
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• pp.18-28
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• 1993

Processes in the real-time distributed control systems share a network medium to exchange their data. Performance of feedback control loops in the real-time distributed control systems is subject to the network-induced delays from sensor to controller, and from controller to actuator. The network-induced delays are directly dependent upon the data sampling times of control components which share a network medium. In this study, an algorithm of determining data sampling times is developed using the "window concept". where the sampling datafrom the control components dynamically share a limited number of windows. The scheduling algorithm is validated through the aimulation experiments.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.75-75
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• 2009

In this study, in order to develop lead-free share-mode ultrasonic motor, finite element method(FEM) simulation were executed using ATILA simulator and their results were investigated. Share mode ultrasonic motor models are made up stator and two ceramic disks and it simulated according to the different ceramic disk dimensions. The results shows optimum ceramic disk dimensions and design.

• Journal of Families and Better Life
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• v.18 no.2
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• pp.93-108
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• 2000

This study examines difference in expenditure patterns between working-wife families and nonworking-wife families. The data used in the study is 4,506 husband-wife families take National Survey of family Income and Expenditure in 1996. Of the sample, 42.3% are working-wife families. Consumption expenditure patterns are analyzed in two ways. One is the budget share of each given expenditure and the other is elasticity of those expenditure. The main results of this study are as follows: First, there are the differences between working-wife families and nonworking-wife families in the budget share of each given expenditure. In the budget shares of each given expenditure, nonworking-wife families share more than working wife families for food and medicine. And working-wife families allocated more on public transportation than their counterparts. Second, there are also differences between working-wife families and nonworking-wife families in income elasticities.

• Health Policy and Management
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• v.5 no.2
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• pp.18-34
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• 1995

To clarify the relationship between the medical supply(medical persons and goods) and the use of bed, the author has made comparison among OECD 24 countries. Per Capita Bed-days can be divided into Average Length of Stay and Admission Rate, and these three variables were regressed upon both In-patient Care Beds of all medical institutions including acute somatic, psychiatric, special, nursing homes and other long-term care and Share of Total Health Employment in Total Employment. The result of regression analysis shows a statistically significant positive relationship between In-patient Care Beds and Average Length of Stay, and negative relationship between Share of Total Health Employment and Admission Rate. In addition to Ordinary Least Square(OLS) estimation, amended Bounded Influence Estimation(BIE) was also made to adjust the influence of outliers. Japan shows a very large number of In-patient Care Beds and a very low Share of Total Health Employment, and this medical situation is judged to have close relation to her long Average Length of Stay and low Admission Rate.

• The Journal of Korean Medicine
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• v.28 no.3 s.71
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• pp.100-107
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• 2007

Objective : To build a basis of a research strategy for development of Korean ginseng as a global competitive medical product in the world market by Korean Oriental medicine group. Methods : Survey of all literature or analysis reports about market patterns related to ginseng or ginseng products in Korea and in other countries. Results : Korean ginseng and it products have rapidly decreased in share of the world market since the 1980s, with Korean ginseng occupying just 3% of the Hong Kong ginseng market in 2005. While Korean ginseng has been satisfied with consumption within the large Korean market itself, it now has only 1% of world market share. Conclusion : A systematic strategy is needed to strengthen global competitiveness of Korean ginseng based upon development of novel customer-tailored ginseng products. In addition, experience and science-based research in the Oriental medicine field should be involved in the process.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.11a
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• pp.7-10
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• 2003

After the launch of PCS in 1997, price competition between five mobile carriers was so severe that the Korean mobile telephony market achieved a remarkable subscriber base growth. But in that optimal pricing behavior depends on how each fm is likely to react to other frims'choice of price, it is very interesting to analyze competitive pricing behavior and understand market structure in terms of pricing competitiveness in the Korean mobile telecommunications market. In this paper, we use structural econometric models in New Empirical Industrial Organization (NEIO) framework. But previously used models in this framework generally assume that market size is fixed and that all firms maximize their profits. To fit in with the Korean mobile telephony market, we derive various models in using NML market share model under the assumptions that market size varies with industry's total attractions and that firms maximize their market share. In this paper, we find that the model under market share maximization with the assumption that market size varies with total attraction shows the best fitting results.