• Journal of Information Science Theory and Practice
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• v.8 no.3
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• pp.47-63
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• 2020

This study focuses on users of activity tracking technologies and their related information behavior. How useful is the provided information by the trackers? Do users understand all information and explanations? We conducted a web-based survey. All in all, 631 users of a tracking device filled out the survey. From the perspective of information science, this investigation aims to analyze information needs considering different types of the provided information by activity tracking technologies. Are users satisfied by using the information on their steps, heart rates, and sleep duration? How do users assess readability about heart rate zones and sleep stages? Additionally, we investigated if users understand how to reflect on and adapt their health behavior based on the received explanations. According to the results, users mainly agree that the received information (raw data as well as - to a lesser extent - aggregated data in the form of corresponding diagrams) is useful, that the explanations are easy to understand, and that they know how to use this obtained information. This investigation enables an in-depth insight into how users are applying the self-quantifying activity and health information and which information needs are satisfied.

• Journal of Communications and Networks
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• v.15 no.3
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• pp.283-291
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• 2013

In this paper, we propose new multiuser detectors (MUDs) based on compressed sensing approaches for the large-scale multiple antenna systems equipped with dozens of low-power antennas. We consider the scenarios where the number of receiver antennas is smaller than the total number of users, but the number of active users is relatively small. This prior information motivates sparsity-embracing MUDs such as sparsity-embracing linear/nonlinear MUDs where the detection of active users and their symbol detection are employed. In addition, sparsity-embracing MUDs with maximum a posteriori probability criterion (MAP-MUDs) are presented. They jointly detect active users and their symbols by exploiting the probability of user activity, and it can be solved efficiently by introducing convex relaxing senses. Furthermore, it is shown that sparsity-embracing MUDs exploiting common users' activity across multiple symbols, i.e., frame-by-frame, can be considered to improve performance. Also, in multiple multiple-input and multiple-output networks with aggressive frequency reuse, we propose the interference cancellation strategy for the proposed sparsity-embracing MUDs. That first cancels out the interference induced by adjacent networks and then recovers the desired users' information by exploiting the low user activity. In simulation studies for binary phase shift keying modulation, numerical evidences establish the effectiveness of our proposed MUDs exploiting low user activity, as compared with the conventional MUD.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.2
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• pp.505-513
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• 2017

In this study, we collected 200,578,703 geo-tweets and removed the twitter bots. Using the concept of activity radius, Twitter users are classified. Users are also divided first into domestic and overseas, and again domestic ones are divided into locals and non-locals. Statistical characteristics of activity strength and active area of Twitter users are described according to activity radius and home region, and the geographical distribution is presented visually. Through a case study of Las Vegas, we have identified the difference in activity strength and active area by the user's home residence. We expect to derive theories about human mobility by analyzing various cities with the method proposed in this study.

• International Journal of Contents
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• v.9 no.2
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• pp.14-21
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• 2013

Current smartphone authentication systems are deemed inconvenient and difficult for users on remembering their password as well as privacy issues on stolen or forged biometrics. New authentication system is demanded to be implicit to users with very minimum user involvement being. This idea aims towards a future model of authentication system for smartphones users without users realizing them being authenticated. We use the most frequent activity that users carry out with their smartphone, which is the calling activity. We derive two basics related interactions that are first factor being arm's flex (AF) action to pick a phone to be near ones' ears and then once getting near ear using second factor from ear shape image. Here, we combine behavior biometrics from AF in first factor and physical biometrics from ear image in second factor. Our study shows our dual-factor authentication system does not require explicit user interaction thereby improving convenience and alleviating burden from users from persistent necessity to remember password. These findings will augment development of novel implicit authentication system being transparent, easier, and unobtrusive for users.

• Journal of Communications and Networks
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• v.11 no.2
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• pp.175-186
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• 2009

A new medium access control (MAC) scheme embedding physical channels into multiband carrier sense multiple access/collision avoidance (CSMA/CA) networks is proposed to provide strict quality of service (QoS) guarantee to high priority users. In the proposed scheme, two priority classes of users, primary and secondary users, are supported. For primary users physical channels are provided to ensure strict QoS, whereas secondary users are provided with best-effort service using CSMA/CA modified for multiband operation. The performance of the proposed MAC scheme is investigated using a new multiband CSMA/CA Markov chain model capturing the primary user activity and the operation of secondary users in multiple bands. The throughput of secondary users is obtained as a function of the primary user activity and other CSMA/CA parameters. It is shown that the new MAC scheme yields larger throughput than the conventional single-band CSMA/CA when both schemes use the same bandwidth.

• Health Policy and Management
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• v.20 no.4
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• pp.126-138
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• 2010

Objectives : The purpose of this study is to evaluate the effects of assistive products usage on activity of daily living for the beneficiary older adults people in Korean long-term care insurance system. The study subjects were divided to assistive products users and non-users among the beneficiary older adults based on Korean long-term care insurance system to compare function improvement of the activity of daily living. Methods : In national wide 12 community elderly care center enrolled the National Health Insurance Corporation, The numbers of 281 beneficiary older adults(long-term care Grade I: 66, Grade II: 58, Grade III: 157) participated in this study. This survey assessment tool for activity of daily living was used the long-term care assessment instrument of the physical functions in the law of Korean long-term care insurance. The function items of Activity of daily living were included in clothing, washing, tooth brushing, bathing, eating, posture converting, stand sitting, move sitting, out of room, using toilet, controlling of stool, controlling of urine, washing hair. According to independence to complete dependence functioning level, remarks pointed 1 to 3 points. The data were analyzed by chi-square, two-way anova using SPSS V. 12.0. Results : The results appeared that the mean score of the functions in activity of daily living of assistive products users was a 27.60, and that of non-users was a 30.66. Assistive products were not effected in Grade I and II recipients, but that effected in Grade III recipients. Conclusion : Preparing for activation of assistive products based Korean long-term care insurance system, the result application as follows is possible. The usage of assistive products could improve the function of daily living activity in older adults. Related to Grade III beneficiary elderly people were improved function in activity of daily living by using assistive products, it is necessary to extend coverage the non-eligible elderly people in Korean long-term care insurance system.

• Journal of Information Technology Services
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• v.13 no.4
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• pp.397-410
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• 2014

For mobile service organizations, it is one of the most important tasks to reflect users' opinions rapidly and accurately. In this study, the process is defined to elicit requirements of software/system improvement for mobile application by extracting and refining from users' opinion in mobile app, and detailed activities procession method in this processing are also proposed. The process consists of 3 activities to get requirements of software/system improvement for mobile app. First activity is to transform mobile app to software structure and define term dictionary. Second activity is to elicit simple sentences based on software from users' opinion and refine them. The last activity is to integrate and adjust refined requirements. To verify the usability and validity of the proposed process and the methods, the outputs of manual processing and semi-automated processing were compared. As a result, efficiency and improvement possibility of the process were confirmed through extraction ratio of requirements, comparison of execution time, and analysis of agreement ratio.

• Korean journal of communication and information
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• v.36
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• pp.348-373
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• 2006

In the era of digital media, one of the most distinctive characteristics is the activity what audience play. This characteristic can be particularly demonstrated in the case of PPV(Pay-Per-View) use. Since this service is related with payment by audience according to each behaviour of their own media use. In doing so, this paper explores the characteristics and behavioral pattern in PPV use. In particular, the study tries to predict from the result that which trait of characteristic can explain the adoption of PPV. The analytical result shows that PPV users are much more active in gathering information as well as achieving the diversity in terms of program choice compared to non PPV users. At the same time, PPV users are prone to be unsatisfied against the other media and naturally willing to adopt the new media. PPV users are much more keen to use toward age related programme classification system in order to protect their children from inappropriate programmes. The variable of participational behaviour is the most relevant variable to predict the degree of PPV use, however, it fails to predict to distinguish the PPV users group from non PPV users group. It maybe given as a conclusion that PPV users are much more active in not only choosing their own program they like to watch but also planning ahead for maximising their pleasure from viewing.

• Journal of the Korean Society for information Management
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• v.38 no.4
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• pp.83-112
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• 2021

This study aims to examine how the specialty of librarians links between users' library experience and their resulting perception of the library in public libraries. After reviewing theoretical background studies, a questionnaire survey was conducted at six public libraries in Seoul and Gyeonggi Province. The analysis of the survey results showed that the perception of librarians' specialty had a mediation effect on the relationship between cultural, educational activity and library perception. However, information activity was not linked by the perception of librarians' specialty and only directly influenced on the library perception. Accordingly, the result raised a question of a discrepancy between the areas where the users gain the value of the library and where the librarians' specialty is perceived and some implications were suggested. This research is meaningful in integrating the users' library experience, librarians' specialty, and the library performance by external point of view on the specialty, traditionally regarded as an internal characteristic of the librarianship.

• International Journal of Advanced Culture Technology
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• v.8 no.1
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• pp.218-225
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• 2020

Purpose Wearable devices are widely used in our daily life. The purpose of this study is to investigate the relationship between persuasive designs of fitness trackers and users' physical activity behavior. Methods To test the research model, data was collected from a web-based survey in China, resulting in an effective sample of 166 usable questionnaires. The survey was restricted only to respondents who wear a fitness tracker. Results The sample surveyed in this study indicated that half of the respondents had been wearing a smart fitness tracker shorter than one year, and only 27% were long-time users (longer than two years). Dialogue support and social support strategies were both proved to be effective in increasing users' workout behavior intention. Social support strategies had a greater effect on behavior change than dialogue support strategies. Conclusion The findings from this study make several contributions to the practice. Wearable devices developers can employ the result from this study to help them design devices, which can persuade people to do more exercises and preserve a healthier life.