• Journal of Communications and Networks
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• v.12 no.4
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• pp.366-374
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• 2010

Coded cooperation is a promising user cooperation scheme. In this paper, we first propose a novel network-coding-based coded cooperation scheme. When a user decodes its partner's information correctly in the first frame, it transmits the combination of the partner's parity bits and its own parity bits through network coding in the second frame. This is distinct from the classical scheme, where the user only transmits the partner's parity bits during cooperation. We analyze the outage probability of the proposed scheme, and show that it achieves a full diversity order. Numerical evaluations reveal that the proposed scheme outperforms the classical scheme when the inter-user channel is poor, yet is worse when the inter-user channel is strong. Also, the results show that the proposed scheme always outperforms that of no cooperation in various channel conditions while the performance of classical scheme is worse than that of no cooperation with the poor inter-user channels. This means that the performance of the proposed scheme is more stable than the classical scheme and the proposed scheme is more tolerant to the poor inter-user channels. To combine the advantages of the proposed scheme and the classical scheme under different inter-user channel conditions, we propose an adaptive solution. This adaptive scheme enhances the system performance considerably in all channel conditions in spite of the inter-user channel quality, at the expense of only one acknowledgement or non-acknowledgement bit.

• Journal of electromagnetic engineering and science
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• v.10 no.2
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• pp.56-60
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• 2010

This paper proposes a new cooperative protocol in which Alamouti's scheme is applied to exploit the advantages of both coded cooperation and Alamouti's scheme. It not only has better than direct transmission but also coded cooperation at appropriate cooperation levels. Simulation results show that the proposed protocol can save approximately 6~7 dB of transmit power to achieve the target BER(Bit Error Rate) compared with coded cooperation. Furthermore, the performance of the proposed protocol does not significantly depend on the qualities of inter-user channels.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.609-610
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• 2005

Science and technology is the power of impelling the economic and social development. Promoting the international sci-tech communication and cooperation is one of the important ways of pulling the economic development of Northeast Asia area. Sci-tech communication and cooperation between the government and the folk are two wings of international sci-tech communication and cooperation. Both are supplemented mutually and indispensable. In order to promote the economic and social development of Northeast Asia area and further strength, some suggestions are put forward, i.e. fully exerting university the main roles in the sci-tech communication and cooperation of Northeast Asia area and fully exerting Liaoning province the important roles in the sci-tech communication and cooperation of Northeast Asia area.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.6
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• pp.1811-1817
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• 2008

According to development of electronic commerce, the university's curriculums related electronic commerce should be renewed and added some chapters. I researched on university curriculums of electronic commerce, which has required by enterprise. In particular, the electronic commerce consist of two parts; IT technology and business management. Therefore it is regarded as a convergence subject. I did a correlation analysis between management's performance of enterprise and importance of university curriculum on electronic commerce. The questionnaire includes demands of enterprise and e-business model on electronic commerce. The result of this research indicates a necessary of changing by correlation ratio. Based on this research result, I suggest extended curriculums for electronic commerce.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.09a
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• pp.114-117
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• 2003

Recently, the aging society is a serious problem; we paid attention to the welfare and a disaster prevention cyber city. In this research, we propose the validity of Safe Human Cooperation Mobility System in Collaboration with Cyber City, and show Vehicle Warehousing Support System as an example.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.5
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• pp.847-851
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• 2006

This paper presents a technology of information fusion between radar and electronic intelligence system. Radar can get range and direction information of targets and electronic intelligence system can get direction and electromagnetic information of targets which can be fused and identified together. We designed an information fusion unit in which information data is able to be added and compared and designed a display unit in which a fused information is totally displayed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.06a
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• pp.453-455
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• 1998

No Abstract, See Full-Text

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.35 no.6
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• pp.568-575
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• 2022

This paper is a study on frequency analysis and electronic noise reduction of energy storage system (ESS). We acquired 4 necessary data for about 2 minutes and 4 seconds using a sampling frequency of 10,000 Hz in ESS. Fast Fourier transform (FFT) was used for electronic noise analysis from the acquired data. As a result, it was confirmed that DC component, fundamental wave, second and higher harmonic component exist. For the attenuation of harmonics, low-pass filter (LPF) was applied. We confirmed that an attenuation of approximately 59.3% appears from the second harmonic. The presence of many harmonic components in the data of the ESS was expected to occur due to the insufficiency of optimization among the modules inside the ESS. Therefore, we propose that a national certification system for ESS should be introduced to settle down the issue properly.

• The Journal of Information Systems
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• v.16 no.2
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• pp.123-144
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• 2007

As the interest in the business-to-business electronic commerce is increasing, many companies are participating in the business-to-business e-marketplaces. As a result, it is important to develop understanding of behaviors of firms that use these e-marketplaces. For this purpose, e-marketplace usage company trust is proposed to affect commitment, long-term orientation and cooperation. This study, which used data from participating in the business-to-business e-marketplace companies, showed acceptable data-fit of proposed model and supported all of research hypotheses. The empirical results indicated that trust take significant effect on commitment, long-term orientation and cooperation, and the commitment affect long-term orientation and cooperation, and the commitment in turn have strong influence on long-term orientation and cooperation. It was confirmed that commitment variable is effective mediator linking trust and long-term orientation and cooperation.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.4
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• pp.1359-1375
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• 2015

Energy efficiency is critical for Wireless Sensor Networks (WSNs) since sensor nodes usually have very limited energy supply from battery. Sleep scheduling and nodes cooperation are two of the most efficient methods to achieve energy conservation in WSNs. In this paper, we propose an adaptive energy optimization approach for target tracking applications, called Energy-Efficient Node Coordination (EENC), which is based on the grid structure. EENC provides an unambiguous calculation and analysis for optimal the nodes cooperation theoretically. In EENC, the sleep schedule of sensor nodes is locally synchronized and globally unsynchronized. Locally in each grid, the sleep schedule of all nodes is synchronized by the grid head, while globally the sleep schedule of each grid is independent and is determined by the proposed scheme. For dynamic sleep scheduling in tracking state we propose a multi-level coordination algorithm to find an optimal nodes cooperation of the network to maximize the energy conservation while preserving the tracking performance. Experimental results show that EENC can achieve energy saving of at least 38.2% compared to state-of-the-art approaches.