• Journal of Convergence Society for SMB
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• v.5 no.1
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• pp.1-6
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• 2015

Recently the disease by eating of the modern prevention, management, and trends in the u-healthcare service that provides healthcare services including health promotion is changing rapidly. However, u-healthcare service is a healthcare information that provides users of the disease can not be analyzed even if the service is stored or not stored in the management server status is giving the inconvenience caused to users of the health services. In this paper, we propose a management method of health care services and a big data formation information that provides users of the disease to facilitate the users of health care services through the use magazine big data information regardless of time and place. The proposed method has the user's bio-information and the measured health information and transmits data through a wired or wireless communication to the medical institution and the user's health information data formation by the big user of the analysis of the health information and the disease of the user feedback to the user.

• The Journal of the Acoustical Society of Korea
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• v.35 no.4
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• pp.272-279
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• 2016

In this paper, the realization of a hearing aid adaptively cancelling feedback noise was considered. Conventional least mean square method in time domain was transformed into frequency domain in order to minimize computational burden. The adaptive filter algorithm was evaluated by Matlab (Matrix laboratory), and it was confirmed by CSR 8675 Bluetooth DSP IC (Digital Signal Processor Integrated Circuit) chip firmware realization. Some remote control features by a smart phone was added to the smart hearing aid for user interface easiness.

• 한국HCI학회:학술대회논문집
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• 2006.02a
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• pp.579-586
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• 2006

모바일 환경에서 휴대폰을 사용하다 보면 무의식적으로 전화를 받지 못하는(Missing call) 상황이 빈번하게 일어난다. 휴대폰에서는 기본적으로 시각 청각 촉각의 다중양식 피드백(Multimodal feedback)을 제공하고 있음에도 불구하고, 이렇게 Missing call 이 발생하는 현상에는 여러 가지 다양한 원인이 존재할 것이다. 본 연구에서는 이러한 원인을 찾기 위해 모바일 환경 내 휴대폰 사용자 행동연구를 실시하여 일반적인 휴대패턴을 분석하고, Missing call과 관련하여 주로 설정하는 수신모드와 휴대패턴의 상호영향을 연구하고자 하였다. 본 연구결과, 모바일 환경에서 휴대폰 수신 탐지능력에는 인지심리학적(감각과 주의관련), 환경적, 행동학적 요인이 영향을 미칠 수 있는 것으로 나타났다. 또한 모바일 환경에서 주로 사용하는 수신모드인 진동모드 설정시, 휴대폰 사용자가 속한 환경에 다른 요인들이 복합적으로 존재할 경우 휴대폰 수신에 대한 탐지만족도가 감소함을 확인할 수 있었다.

• Journal of KIISE:Software and Applications
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• v.31 no.8
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• pp.1062-1072
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• 2004

Collaborative filtering systems based on ｛user-document｝ matrix are effective in recommending web documents to user. But they have a shortcoming of decreasing the accuracy of recommendations by the first rater problem and the sparsity. This paper proposes the automatic preference rating method that generates user profile to solve the shortcoming. The profile in this paper is content-based collaborative user profile. The content-based collaborative user profile is generated by combining a content-based user profile with a collaborative user profile by mutual information method. Collaborative user profile is based on ｛user-document｝ matrix in collaborative filtering system, thus, content-based user profile is generated by relevance feedback in content-based filtering systems. After normalizing combined content-based collaborative user profiles, it automatically rates user preference by reflecting normalized profile in ｛user-document｝matrix of collaborative filtering systems. We evaluated our method on a large database of user ratings for web document and it was certified that was more efficient than existent methods.

• Korean journal of communication and information
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• v.32
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• pp.147-168
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• 2006

This study attempts to evaluate the Korean terrestrial television networks‘ internet site effectiveness, specifically in addressing user motivations and user evaluations and in gauging the broadcasters' feedback. The result shows that the primary motive for using a broadcaster's internet homepage was to obtain information. Overall, the users tended to be dissatisfied with the services, especially with regards to its navigational structure and design and with the insufficient number of appropriate content items. The reason cited highest for dissatisfaction was the fee-based services. Among the three networks, Seoul Broadcasting System, the sole commercial network, received the most complaints from the respondents in this respect. The study results reveal that broadcasters' feedback systems to users were deemed responsive and timely, but a true interactivity between the broadcasters and the viewers was lacking. In conclusion, network televisions' internet sites and increased content access through them have provided a platform for increased communication with their viewers, however, these sites are not yet being fully utilized as effective interactive communication feedback channels but more as a unidirectional information source. In addition, the network television services seem to be lacking in providing users with efficient navigational structure, good design, or adequate content level and quality. Thus, to better serve the public, it is recommended that they improve internet homepage usability by assessing and applying qualitative researches regarding the users.

• Journal of the Korean Society for Library and Information Science
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• v.39 no.3
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• pp.75-91
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• 2005

The popularization of the internet has produced an explosion in amount of the information. The importance of web personalization is being more and more increased. The personalization is realized by learning user's interest. User's interest is changing continuously and rapidly. We use user's profile to represent user's interest. User's profile is updated to reflect the change of user's interest. In this paper we present an adaptive learning algorithm that can be used to reflect user's interest that is changing with time. We propose the User's profile model. With this profile user's interest is learned based on user's feedback. This approach has applied to develop hybrid recommendation system.

• Journal of the Korea Society of Computer and Information
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• v.22 no.3
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• pp.53-60
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• 2017

The purpose of this study is to provide empirical and quantitative analysis on user's perceived privacy, security, and user satisfaction when providing visualization information about objects and service provider behaviors that users can not perceive in internet service process. Through previous research, we have examined the importance of privacy and security factors as a key factor to be considered for the characteristics of the Internet of things and the Internet of things. In addition, service blueprint, which is one of the service design methodologies to examine the flow of service usage in providing Internet service of things, was examined. In the flow of things internet service utilization, it is found that the things that are out of the user's cognitive area and the behavior of the service provider take up a large part. Therefore, the hypothesis that the trust of the Internet service security and the satisfaction of the user experience can be improved by providing the security visualization information about the behavior of the object and the invisible service provider in the non-contact aspect of the user and the object. In order to verify the hypothesis, we conducted experiments and questionnaires on the use of virtual objects' internet environment and conducted statistical analysis based on them. As a result, it was analyzed that visual information feedback on non - contact and invisible objects and service provider's behaviors had a positive effect on user's perceived privacy, security, and satisfaction. In addition, we conclude that it can be used as a service design evaluation tool to eliminate psychological anxiety about security and to improve satisfaction in internet service design. We hope that this research will be a great help for the research on application method of service design method in Internet environment of objects.

• Journal of information and communication convergence engineering
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• v.9 no.2
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• pp.193-196
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• 2011

Transmit antenna selection techniques are prominent since they exploit the spatial selectivity at the transmitter side. In the literature, antenna selection techniques assume full knowledge of the channel state information (CSI). In this paper, we consider that the CSI is not perfectly known at the transmitter; however, a quantized version of the channel coefficients is fed back by the users. We employ the non-uniform Lloyd-Max quantization algorithm which takes into consideration the distribution of the channel coefficients. Simulation results show that the degradation in the BER of the system with imperfect CSI at the transmitter is tolerable, especially when the transmit diversity order is high.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.3
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• pp.1156-1173
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• 2021

In this paper, we propose a new joint precoder and postcoder design strategy to support multiple streams per user in multiuser multiple-input multiple-output (MIMO) systems. We propose two step precoding strategies using equal channel gain decomposition and block diagonalization at the transmitter. With the proposed precoder, the multiuser MIMO channel can be decomposed into multiple parallel channels with equal channel gain per user. After applying receive postcoder which is generated and sent by the transmitter, we can use ML based decoder per stream to achieve full receive diversity. Achievable sum rate bound and diversity performance of the proposed algorithm are presented with feedback signaling design and quantitative complexity analysis. Simulation results show that the proposed algorithm asymptotically approaches to the sum rate capacity of the MIMO broadcast channel while maintaining full diversity order.

• Journal of Information Technology Applications and Management
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• v.31 no.1
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• pp.163-175
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• 2024

This study conducts topic modeling analysis on four electric scooter sharing platforms: Alpaca, SingSing, Kickgoing, and Beam. Using user review data, the study aims to identify key topics and issues associated with each platform, as well as uncover common themes across platforms. The analysis reveals that users primarily express concerns and preferences related to application usability, service mobility, and parking/accessibility. Additionally, each platform exhibits unique characteristics and challenges. Alpaca users generally appreciate convenience and enjoyment but express concerns about safety and service areas. SingSing faces issues with application functionality, while Kickgoing users encounter connectivity problems and device usability issues. Beam receives overall positive feedback, but users express dissatisfaction with application usability and parking. Based on these findings, scooter sharing service providers should focus on enhancing application features, stability, and expanding service coverage to meet user expectations and improve customer satisfaction. Furthermore, highlighting platform-specific strengths and providing tailored services can enhance competitiveness and foster continuous service growth and development.