• Journal of Korea Society of Digital Industry and Information Management
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• v.12 no.4
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• pp.163-169
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• 2016

This study is to analyze factors affecting a growth of online community with perspectives of social network. Particularly this study tries to explore structural phenomenon built by interactions between users in a certain of free board belonging to the online community, in which focuses on one's writing a comments responding on those of others. With using SNA(Social Network Analysis), the social network data calculated from users' interaction shown as their comments were collected to draw out each individual's centrality value representing the structure of the online community and also we estimated duration time and the number of each comments as a proxy variable representing growth of the online community. And then cause-and-effect relationship between individual's centrality value and the duration time and the number of each comment were analyzed. As a result of the analysis, Core-Periphery, Centralization and Reciprocity have significant effects on the duration time and the number of each comment, therefore those significant values representing online structure will give an implication to manage, to promote the online community, to forecast its evolution path and to build critical policies.

• Journal of the Korean Society for Nondestructive Testing
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• v.20 no.2
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• pp.110-115
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• 2000

The electromechanical reciprocity identity is introduced to relate the voltage at the terminals of a transducer to the acoustic wavefields scattered from the specimen. The voltage at the terminals of the transducer is expressed as an integral equation in terms of the displacement and stress of the incident and scattered waves on the closed surface enclosing the scatterer. The equation is used to relate the voltage at the terminals of an acoustic microscope's transducer to the acoustic wavefields at the interface between the specimen and the coupling fluid. The voltage calculated using the integral equation is compared with the experimental result.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.2 no.5
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• pp.253-264
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• 2008

Cyclic delay diversity (CDD) is considered a simple approach to exploit the frequency diversity, to improve the system performance in orthogonal frequency division multiplexing (OFDM) systems. Also, the linear precoding technique can significantly improve the performance of communication systems by exploiting the channel state information (CSI). In order to achieve enhanced performance, we propose applying linear precoding to the conventional CDD-OFDM transmit diversity schemes over Rayleigh fading channels. The proposed scheme works effectively with the accurate CSI in time-division-duplex (TDD) OFDM systems with CDD, where the reciprocity is assumed instead of channel state feedback. For a BER of $10^{-4}$ and the mobility of 3 km/h, simulation results show that a gain of 6 dB is achieved by the proposed scheme over both flat fading and Pedestrian A (Ped A) channels, compared to the conventional CDD-OFDM system. On the other hand, for a mobility of 120 km/h, a gain of 2.7 dB and 3.8 dB is achieved in flat fading and Vehicular A (Veh A) channels, respectively.

• Health Policy and Management
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• v.24 no.3
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• pp.291-300
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• 2014

Background: The efficient knowledge management in hospital organization is generally known as the important activities relevant to employees' knowledge sharing behavior and work performance. This research examined factors affecting employees' knowledge sharing behavior and work performance in top 4 university hospitals. This study is based on individual factors such as incentives, reciprocity, behavioral control, and subjective norms. Also, there are organizational factors such as CEO support, learning climate, IT system, rewards system, and trust. Methods: Data was collected from employees who are working at 3 hospitals university in Seoul and 1 university hospital in Gyeonggi-Do through the self-administered questionnaires. A total of 779 questionnaires were analyzed by PASW SPSS ver. 18.0. (SPSS Inc., Chicago, IL, USA). Results: The significant variables affecting knowledge sharing behavior are behavioral control (in individual factor) and CEO, IT system, and trust (in organization factor). Also the significant variables affecting work performance are incentives, reciprocity, subjective norms, and behavioral control (in individual factor) and CEO support, IT system, reward system, and trust (in organization factor). Conclusion: The personality and organization characteristics factors is important to improve knowledge sharing behavior and work performance of hospital employees. Therefore, to make more efficient knowledge management is to build and system knowledge sharing culture, system, and leadership and to develop practical strategies.

• Journal of Korea Game Society
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• v.12 no.4
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• pp.3-12
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• 2012

This study discusses how players make the mutually cooperative mechanism in Social Games. In SNG, many players exchange helps each other. That mechanism is not only one-off but also repetitive process. In the perspective of reciprocity in Evolutionary psychology and Mythology, this study analyzes mutual cooperation in several game texts most well known in the SNG field. According to the field study results, four cooperative mechanisms were extracted. These 4 principles apply to every digital game design for emerging of cooperative storytelling among players.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.20 no.4
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• pp.338-347
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• 2010

Heunginjimun designated as a Treasure No.1 is a two-story wooden structure with 5 bay and 2 bay in its front and side views, respectively. This paper presents an investigation on vibration characteristics of Heunginjimun through both ambient vibration and impact hammer tests. Ambient vibration test was performed to identify the natural frequency of Heunginjimun from the spectrum analysis of time history. Impact hammer test was undertaken to find the frequency of Heunginjimun which is affected by the surrounding traffics and to verify the reciprocal principle for the wooden structural system. Ambient vibration test results of Heunginjimun showed that the natural frequencies in two principal axes 1.5 Hz and 1.1 Hz, respectively. It was confirmed from impact hammer tests for a ground that the frequency of 4.2 Hz is caused by the traffics surrounding Heunginjimun. It was also observed that from the impact hammer test results between two locations in Heunginjimun that the transfer functions measured from two corresponding locations coincided well with each other. This result shows that the wooden structural system is globally linear, and the reciprocal principle is established.

• The Journal of Information Systems
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• v.25 no.1
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• pp.135-158
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• 2016

Purpose Virtual communities change the way people communicate and share information. The purpose of this paper is to find how internet social capital and individual motivations influence the information sharing in virtual communities. This study considers the social capital theory, individual motivations, information sharing, and community promotion to construct a theoretical model. Design/methodology/approach Social capital focuses on three dimensions that include 6 factors: social interaction ties, centrality, shared language, shared vision, trust and reciprocity. Individual motivations include 2 factors: reputation and enjoy helping. To confirm the research model and the hypotheses, 426 effective questionnaires were used for the final analysis. Findings The result of data analysis demonstrates that social interaction ties, centrality, shared language, trust, and reciprocity were significant in affecting information sharing behaviors. However, reputation, enjoy helping, and shared vision does not appear to have a significant influence on information sharing behaviors. The information sharing was positively related to community promotion.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.5A
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• pp.542-548
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• 2008

This paper proposes a handover scheme using uplink and downlink signals in IEEE 802.16e systems. Exploiting the channel reciprocity in TDD systems, the proposed scheme triggers handover initiation process using uplink signal. In addition, it exploits the uplink and downlink hysteresis to determine the handover direction. Simulation results show that the proposed algorithm with joint hysteresis reduces the outage probability by about 10% compared with the mobile assisted handover in IEEE 802.16e.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.10 s.89
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• pp.1005-1010
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• 2004

An analysis method of slot-coupled microstripline to waveguide transition is presented to developed a simple but accurate equivalent circuit model. The equivalent circuit consists of an ideal transformer, microstrip open stub, and admittance elements looking into a waveguide and a half space of feed side from a slot center. The related circuit element values are calculated by applying the reciprocity theorem, the Fourier transform and series representation, the complex power concept, and the spectral-domain immittance approach. The computed scattering parameters are compared with the measured, and good agreement validates the simplicity and accuracy of the proposed equivalent circuit model.

• Journal of the Korean Society for Library and Information Science
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• v.43 no.3
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• pp.297-312
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• 2009

This study examined the intrinsic and extrinsic motivational factors affecting the intention to contribute knowledge to online communities. It examined enjoyment, knowledge self-efficacy, and commitment as the intrinsic motivational factors, and anticipated reciprocity, image, and subjective norm as the extrinsic motivational factors. The results showed that intrinsic motivational factors, enjoyment and knowledge self-efficacy were found to have significant influences on attitudes towards knowledge contribution to online communities, but commitment was not. Of the extrinsic motivational factors, anticipated reciprocity was found to have a significant influence on attitudes toward knowledge contribution to online communities, but image and subjective norm were not.