• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.1007-1008
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• 2009

• Transactions of Materials Processing
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• v.21 no.7
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• pp.441-446
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• 2012

A sequential coupled field analysis of electromagnetic free bulging was performed by using FEM. A 2D axi-symmetric electromagnetic model based on the magnetic vector potential is proposed for the calculation of magnetic field and Lorentz's forces. The Newmark integration method is used to calculate the transient dynamic plastic deformation of sheet during free bulging. In the finite element model, the effect of sheet deformation on the electromagnetic field analysis is taken into consideration. In order to confirm the sequential electromagnetic-mechanical coupling analysis, an experiment with an electromagnetic forming apparatus was conducted. The results showed that the final bulge height of the sheet predicted from the proposed method is in good agreement with experimentally measured height.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.7
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• pp.673-678
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• 2009

The efficiency of active sonar that is used underwater observation equipment is important for obtain the information of topography and trace for the objects. Sound wave transmitted from sonar are distorted by acoustic window which is to protect sonar. Making various sonar dome is impossible for experiment, because consumed unnecessary time and expense. So, the purpose of this study is to simulate and analyze the acoustic window propagated sound wave from sonar for designing model reduced insertion loss. Simulation is performed by transient analysis and fluid-structure interaction analysis. As a result, this study will give a opportunity for efficient design of sonar dome without high cost and time consumption.

• Knowledge Management Research
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• v.16 no.3
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• pp.81-102
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• 2015

With the rapid development of digital media, there has been a huge change in a way of communication, a process of information diffusion and a role of traditional media. Not like mass media, social media enables users to generate and tap into the opinions of a larger world. From that reason, social media is impacting marketing strategies. However, still social media marketing researches just focus on case study, analysis of users motivation or analysis of power user's usage pattern. Word-of-mouth has always been important especially in marketing area. In social media, word-of-mouth depends on each user that's why this research focuses on individual user's activity in SNS. I defined 4 factors (produce, diffusion, network size, activity of network size enlarge) that are effect on activity and verified hypothesis by multiple regression analysis, hierarchical regression analysis and moderated multiple regression.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.21 no.5
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• pp.393-399
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• 2011

An empirical formula proposed by Petersson and Plunt(PP's formula) and finite element analysis for impedance calculation of ship equipment foundations are investigated by comparing the analysis results with those of experimental results. The PP's formula well estimates resonant frequency of the foundations and impedance level except around the resonant region although the impedance level around the resonant frequency is heavily dependent upon the assumed loss factor. The results show that the PP's formula and finite element models can be complementarily used to estimate the impedance characteristics of various types of foundation of ships in design stage.

• Animal Systematics, Evolution and Diversity
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• v.34 no.3
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• pp.162-167
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• 2018

To confirm the genetic identification and phylogenetic relationships of unidentified 6 baleen whales by-caught from 2002 to 2016, a partial sequence of approximately 500 base pair (bp) of the mitochondrial DNA (mtDNA) control region was analyzed and compared to published sequence from Genbank. Our results indicated that the two individuals among 6 specimens are clustered with Omura's whale clade through phylogenetic analysis, which had only a single haplotype. Omura's whale was reclassified as a new species in 2003 and they had not been previously reported in Korean waters. This study firstly revealed existence of Omura's whale in Korean waters by molecular analysis based on mtDNA control region.

• Journal of Wellness
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• v.7 no.2
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• pp.25-37
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• 2012

The purpose of this study was to analyze the mass media's news framing on the elderly leisure. For this, researchers collected news articles from daily newspapers such as Chosun Ilbo, Hankyoreh, Kyunghyang Shinmun, and analysed the news framing of them through text-analytic approach. Total of 153 news the about elderly leisure between 1990 and 2010 were used for frame analysis. The Frame analyses were divided by formal frame and content frame. The formal frame was formed by deduction based on the classification method of Iyergar(1991) and the content frame was formed by induction according to the analysis of overall themes and titles of news. The main result could be summarized as follows: First, the analysis of formal frame showed that the episodic frame was predominantly high which focused on specific event or occurrences about elderly leisure. Second, it was found by content frame analysis that elderly leisure's facilities, health, serious leisure, policy frame were main subjects of news framing.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2006.05a
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• pp.304-307
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• 2006

A plane stress yield function YLD2000(Yoon et al., 2000) is applied to the finite element analysis S/W Z-Stamp because it is required to conduct proper consideration of aluminum alloy which has anomalous behavior. In the previous study, verification of the yield function and developed S/W is implemented. In this paper, two real parts of automobile body are additionally considered to verify the validity of Z-Stamp. The one is the benchmark problem #2 of Numisheet 2005 and the other is a small member part. In case of benchmark problem, formability simulation result and try-out result are compared with each other. In case of the small member part, formability analysis is implemented to predict the problem during the developing time.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.2 no.2
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• pp.142-154
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• 1990

A theoretical cycle analysis has been performed for a basic heat pump, charged with non-azeotropic refrigerant mixtures, R22/R114 and R13B1/R152a. At first, a procedure is introduced to calculate thermodynamic properties simply and correctly, and the advantages of using refrigerant mixtures are discussed through the cycle analysis. It is shown that by using refrigerant mixtures in the heat pump, several improvements can be made. In comparison with conventional pure refrigerants, the application of refrigerant mixtures results in high reliabilities caused by the extension of the application limit, energetic improvements, and a continuous capacity control. From generalizing various results, the optimum compositions in refrigerant mixtures are also determined. The 30%/70% and 40%/60% compositions are selected for R22/R114 and R13B1/R152a, respectively.

• Journal of the Korean Society for Library and Information Science
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• v.57 no.3
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• pp.351-379
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• 2023

The goal of this study is to investigate the domestic and international research trends on metaverse related researches. To achieve this goal, a set of 913 journal articles were collected from KCI (Korea Citation Index), 232 articles from WoS (Web of Science), and 277 articles from WoS-CPCI (Conference Proceeding Citation Index). A descriptive analysis shows the number of researches has been increased radically, and the mostly researched subject areas are interdisciplinary, computer science, and education in KCI, business and economics in WoS, and computer science in WoS-CPCI. The co-occurrence network analysis using author keywords revealed that technology related terms such as virtual reality and augmented reality showed high centrality measures in all of the databases, and the cluster analysis resulted in education and metaverse platform related keywords cluster from KCI, bibliometric analysis related keywords cluster from WoS, and all the metaverse technology related keywords cluster from WoS-CPCI.