• Journal of Communications and Networks
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• 제12권4호
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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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• 제10권2호
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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.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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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.

• 한국산학기술학회논문지
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• 제9권6호
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• pp.1811-1817
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• 2008

기업이 요구하는 대학의 전자상거래 교과과정을 연구하였다. 전자상거래 발전과 함께 교과과정의 변화도 필요하다. 특히 전자상거래시스템은 기술과 경영 분야가 모두 중요하므로 교과과정이 융합 학문(경영학, 공학)이라고 할 수 있다. 본 연구에서는 전자상거래 e-비즈니스 모델과 기업의 실무적 요구를 반영한 대학의 효과과정 개발을 위해 기업의 경영성과와 교과과목의 중요성을 조사하여 상관분석을 시도하였다. 상관도에 따라서 교과과정의 변화의 필요성을 제시하였다. 결과적으로 경영 분야의 교과과정 확대가 필요하다고 분석되었다.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2003년도 ISIS 2003
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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.

• 한국산학기술학회논문지
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• 제7권5호
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• pp.847-851
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• 2006

본 논문에서는 레이더와 전자정보 장비를 사용해서 획득한 각각의 정보를 종합해서 레이더에서 획득한 표적신호와 전자정보에서 획득한 전자파 정보를 융합하는 기술을 제시한다. 레이더와 전자정보 장비를 융합하면 표적을 정확하게 확인할 수 있기 때문에 레이더의 탐지 오차율이 줄어들고 표적에 대한 상세 정보를 확보할 수 있으며, 정보융합 모듈에서 융합한 내용을 종합표시기에서 통합된 정보를 표시할 때 장비의 성능을 향상시킬 수 있으며 표적식별이나 목표물 선정에 사용할 수 있다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1998년도 춘계학술대회 논문집
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• pp.453-455
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• 1998

No Abstract, See Full-Text

• 한국전기전자재료학회논문지
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• 제35권6호
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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.

• 한국정보시스템학회지:정보시스템연구
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• 제16권2호
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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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• 제9권4호
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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.