• Journal of Distribution Research
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• v.12 no.3
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• pp.69-90
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• 2007

This study is set out to investigate the factors that influence customers' behavior of choice and switching between online and offline channels, separating the purchase decision into two stages, i.e., information search and purchase. Factors influencing channel choice are found to differ from stage to stage. The main results of this study are as follows. At the information search stage, customers' channel knowledge had impacts on the choice of the channel. Customers are more likely to visit offline bookstores when they have hedonic shopping orientation and higher involvement level with books. On the contrary, customers are more apt to search online when they have a lot of online shopping experiences. At the purchase stage, the results varied according to the search channel. When customers search for information online, the following variables lead to online purchases: online shopping experiences with books, price-focused shopping orientation, and time availability for shopping. Perceived risk made customers purchase offline even though they searched online. In case of offline searching, customers with more convenience-focused, hedonic-focused shopping orientation and less tim availability purchased offline.

• Proceedings of the KIEE Conference
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• 1999.07d
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• pp.1836-1838
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• 1999

다결정 실리콘 박막 트랜지스터(TFT)의 누설전류를 줄이기 위하여 채널의 중간에 선택적으로 도핑된 영역을 가진 새로운 다결정 실리콘 TFT를 제안한다. 제안된 TFT에서는 채널의 일부가 선택적으로 도핑되어 채널 전체에 걸리는 전기장이 재분배된다. 제안된 n-채널 TFT는 $V_{GS}$<0, $V_{DS}$>0인 조건에서, 대부분의 전기장이 드레인 접합에 형성되는 공핍영역과, 도핑된 영역 중 소오스 쪽과 도핑되지 않은 채널 사이에 형성되는 공핍영역에 각각 나뉘어 걸린다. 기존의 다결정 실리콘 TFT와 비교할 때 드레인 접합에서 걸리는 전기장은 1/2로 감소하였고, 이에 따라 드레인 접합에서 생성되는 전자-홀 쌍도 현저히 감소하였다. 더구나 제안된 TFT의 온-전류는 기존의 TFT와 비교했을 때 거의 같거나 약간 감소하였으며 이에 따른 온/오프 전류비가 현저히 향상되었음을 실험을 통해 확인할 수 있었다.

• Journal of Digital Convergence
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• v.18 no.6
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• pp.255-269
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• 2020

This paper aims to analyze the factors influencing consumer's choice of smartphone purchase channel in multichannel environments. Recently, smartphone purchase channels are becoming more complex and diverse. A smartphone with a short purchase cycle is a product applying advanced technology, the research of this topic would be significant. The major findings of this study are as follows. First, depending on the consumer's shopping orientation, the consumer group was classified into three groups of preference 1. Active shopping, 2. Convenient shopping, and 3. Rational shopping. Second, it was analyzed that the consumer's shopping orientation influenced the decisions of the information search channel and the purchase channel. Third, there was a significant difference between the search and purchase channels in the three groups. Finally, in the channel experience, there was a significant difference in price satisfaction by group. The results of these studies are expected to provide practical implications for establishing a customized multi-channel strategy. This study provides a desirable model for research on smartphone purchase channels.

• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.6
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• pp.774-779
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• 2012

Brain-computer interface based on motor imagery is a system that transforms a subject's intention into a control signal by classifying EEG signals obtained from the imagination of movement of a subject's limbs. For the new paradigm, we do not know which positions are activated or not. A simple approach is to use as many channels as possible. The problem is that using many channels causes other problems. When applying a common spatial pattern (CSP), which is an EEG extraction method, many channels cause an overfit problem, in addition there is difficulty using this technique for medical analysis. To overcome these problems, we suggest a binary particle swarm optimization with channel impact factor in order to select channels close to the most important channels as channel selection method. This paper examines whether or not channel impact factor can improve accuracy by Support Vector Machine(SVM).

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.7
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• pp.55-61
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• 2004

This paper proposes an antenna selection and switching system between spatial multiplexing and diversity techniques. The proposed system overcomes spatial correlation by using antenna selection method and improve bit error performance with switching encoding nudes between a spatial multipexing encoder and a diversity encoder. Therefore, in a 4 transmit and 2 receive antenna system first, the proposed system selects 2 transmit antennas, and next, switches encoding modes between Space-Time Transmit Diversity and BLAST according to instantaneous channel information. Computer simulations showed that the proposed system improves about 2 or 3 ㏈ SNR in low correlated channel and about 3 ㏈ SNR in highly correlated channel rather than a 2 by 2 antenna switching system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.3
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• pp.459-468
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• 2015

In this paper, we consider an uplink multiuser hybrid beamforming system where an access point (AP) communicates with multiple users simultaneously. The performance of the uplink multiuser hybrid beamforming system depends on the effective channel which is given by the product of the channel matrix and the analog beams. Therefore, to maximize the performance, we need to obtain the channel information and then select the analog beams appropriately by using the acquired channel information. In this paper, we propose the channel estimation method and low complexity analog beam selection algorithm for the uplink multiuser hybrid beamforming system. Additionally, our analysis shows that the proposed low complexity analog beam selection algorithm provides much less complexity than the optimum analog beam selection algorithm. From the numerical results, we confirm that the proposed low complexity analog beam selection algorithm has little performance degradation in spite of much less complexity than the optimum analog beam selection algorithm under the equal system configuration.

• Journal of Broadcast Engineering
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• v.7 no.2
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• pp.88-95
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• 2002

According to an evolution of digital broadcasting, it is possible that terrestrial and satellite broadcasting media provide multi-channel services. CATV and satellite media have been also extended to hundreds of channels. As the result of channel expanding, viewers came to select lots of channels. But it is difficult that they select the favorite channel among hundreds of channels. In this paper, we propose an efficient automatic method to recommend channels and programs on a viewer's preference in a multi-channel broadcasting receiver like a Set ToP Box(STB). The proposed algorithm selects channels based on the following method. It makes and saves user history data by using MPEG-7 MDS based on the program information a viewer had watched. It recommends programs similar to a viewer's preference based on user history data. It selects the channel in the recommended genre based on the viewer's channel preference. The experimental result shows that the proposed scheme is efficient to select the user preference channel.

• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.116-120
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• 2008

The conventional channel selection method for a ZigBee communication network basically detects the energy values in all channels. In the ISM band, no license is required to use channels in this band, so there may exist various interference factors in this band. It is well known that WLAN is the major interference factor degrading the performance of ZigBee in the ISM band. In this paper, we propose an efficient channel selection algorithm which uses the pattern of WLAN channel uses as the a priori information. By using the proposed algorithm, we may save the time required to select channels for the ZigBee communications.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.909-914
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• 2005

This paper proposes an efficient antenna selection scheme for PRT (Personal Rapid Transit) remote control in a wireless MIMO-OFDM systems. Using high correlation among neighboring sub-carriers, transmit antennas are selected by calculation based on the channel response of the center sub-carrier in each subgroup. This scheme reduces complexity of selection algorithm and significantly reduces the feedback channel information with small performance degradation. Especially, when feedback channel rate between a control base and a train is fixed, the proposed scheme can provide a significant advantage in high mobility.

• Proceedings of the Korean Information Science Society Conference
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• 2012.06b
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• pp.72-74
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• 2012

본 논문은 미래 군에서 CR (Cognitive Radio) 기술을 적용한 전투무선망에서의 효율적인 주파수 사용을 위한 정책기반 동적 채널 선정 구조를 제안한다. 전투무선망에서는 상용의 기지국과 같은 Coordinator가 존재하지 않기 때문에 효율적인 채널 사용을 위해서 각 상황마다 어떻게 대응할 것인가에 대한 고려사항이 있다. 이에 대한 해결책으로 정책기반의 동적 채널 선택 구조를 제안하며, 이는 각 상황에 따른 규칙이나 행동을 사전에 정책으로 정의하여 특정 Coordinator가 없더라도 해당 상황이 발생하면 사전 정의된 정책에 의해서 동적 채널 선택을 하는 것이다. 즉, 전투무선망에서 작전상황이나 전술통신환경의 변화에 따라 PU (Primary User)나 SU (Secondary User)를 동적으로 할당하는 것을 의미한다. 모의 실험결과 별도의 정책 없이 Random하게 동적 채널을 선택하는 기존기법보다 정책기반의 기법이 월등한 성능향상을 보였다.