• Journal of Korea Society of Digital Industry and Information Management
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• v.14 no.3
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• pp.77-85
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• 2018

Multi-User Multiple-Input Multiple-Output (MU-MIMO) is the core technology for improving the channel capacity compared to Single-User MIMO (SU-MIMO) by using multiuser gain and spatial diversity. Key problem for the MU-MIMO is the user selection which is the grouping the users optimally. To solve this problem, we adopt Extreme Value Theory (EVT) at the beginning of the proposed algorithm, which defines a primary user set instead of a single user that has maximum channel power according to a predetermined threshold. Each user in the primary set is then paired with all of the users in the system to define user groups. By comparing these user groups, the group that produces a maximum sum rate can be determined. Through computer simulations, we have found that the proposed method outperforms the conventional technique yielding a sum rate that is 0.81 bps/Hz higher when the transmit signal to noise ratio (SNR) is 30 dB and the total number of users is 100.

• Journal of Digital Convergence
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• v.6 no.4
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• pp.105-112
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• 2008

Even though, many enterprises began to use management information system, they were not able to attain remarkable outcome. Thus, a purpose for this research is to explore effect that characteristics of information technology and executive support have on its user's confrontation In order to verify this purpose, we selected Nong-hyup's CRM as an object for a proof of effect that characteristics of information technology and executive support have on its user's confrontation. According to this research's conclusion, characteristics of information systems have notable influence on user's confrontation, while executive support did not have significant influence on it. Yet, this research has its limits by considering characteristics of information technology and support from board of directors as only variables among many other possible reasons for user's confrontation. Thus, in the future, there should be another research that considers more various reasons for user's confrontation.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1992.04b
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• pp.433-433
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• 1992

• International Journal of Contents
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• v.11 no.4
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• pp.44-55
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• 2015

There has been a significant paradigm shift in the book industry from print to digital, with the increased use of electronic books (e-books) on e-book readers. The major online booksellers and publishers are devoting their energies to the growth of the e-book market, resulting in an upward spiral in e-book usage, and a resultant increase in the number of downloaded e-books in an e-book reader library. However, there are comparatively few features for e-book management and search in most e-book reader libraries, particularly in smartphone environments. In addition, the user interfaces of e-book management in e-book readers are highly diverse, which has led to major usability issues. In this paper, we analyze user preferences for e-book management and search in the libraries of the five most commonly used e-readers for the Android smartphone platform via a questionnaire survey. Then, we suggest ideal alternatives in addition to user-friendly features based on user preferences for managing e-book libraries, to allow users to more easily browse collections, thereby enhancing the usability of e-book readers.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.10
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• pp.897-907
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• 2020

The development of information technology and the demands of society on an application in an operating system, as well as increasing the specifications and sophistication of smartphones, require banks to make changes to their mobile banking applications. The transformation of the mobile banking application into a digital banking application conducted by banks has made users re-evaluate based on their preferences. This study presents the behavior of users of digital banking applications in Yogyakarta, Indonesia. The hypothesis model is based on Technology Acceptance Model (TAM) with additional factors of the social image, perceived risk and perceived trust adopted from Muñoz-Leiva et al. (2017). The methodology in this study includes data collection through questionnaires distributed online and data analysis using the Structural Equation Model. The results of this study illustrate that the perceived trust and perceived risk have a more dominant part in influencing user attitude and user intention to use digital banking. Meanwhile, social image, perceived ease-of-use and perceived usefulness are not significant in influencing user attitude and user intention to use digital banking. The implication of this research helps to determine the right communication and strategy so that more users with more benefits can utilize this digital banking application.

• Journal of Korea Society of Digital Industry and Information Management
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• v.4 no.2
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• pp.101-108
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• 2008

In this paper, we develop system to backup automatically personal data by real time based on ECA model. This system backups data that is changed in user PC using CDP technology based on ECA model. Proposed ECA model defines file's change such as file creation, update, remove etc. in user PC to event for synchronization between server and user PC. If event is detected about file, proposed system examines condition that is defined and backup the file to server. Backup data that is stored to server can recovery on point of time that user wants. The proposed system can be applied to data management system for business, personal data management system, high-capacity contents management system etc.

• Journal of Korea Society of Digital Industry and Information Management
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• v.8 no.4
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• pp.99-105
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• 2012

Recently, there are many user selection algorithms in multi user multiple-input multiple-output (MU-MIMO) systems. One of well-known user selection methods is Semi orthogonal user selection (SUS). It is an algorithm maximizing channel capacity. However, it is applicable only when user's antenna is one. We propose a generalized user selection algorithm regardless of the number of user's antennas. In the proposed scheme, Base station (Bs) selects the first user who has the highest determinant of channel and generates a user group that correlation with first user's channel is less than allowance of correlation. Then, each determinant of channels made up of first user's channel and a user's channel in the generated group is calculated and BS selects the next user who has the highest determinant of that. BS selects following users by repeating above procedure. In this paper, we get better performance because of selecting users who have the highest determinant of channel as well as allowance of correlation optimally calculated through matrix operations.

• Journal of Korea Society of Digital Industry and Information Management
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• v.5 no.3
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• pp.47-57
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• 2009

Computing environments are being more and more various due to the development of technologies. While existing computing environments used for fixed locations or particular purposes by requesting big scale monitors or complicate calculation performance, recent computing environments are used for a variety of locations and for a diversity of purposes by using various devices. Because of the needs, digital device convergence, which emphases portability and mobility, came out. However, almost researches for user interface are performed for big scale monitors or complicate calculation performance until now. By the reason, user interface on each small device is different from others, or is not appropriate for the purpose of small device. Therefore, this research is to design Zoomable User Interface (ZUI) that adapts for small devices by adding the existing user interface on small devices and haptic technologies, and to implement a user interface for PDA devices.

• Journal of the Korea Society of Computer and Information
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• v.29 no.7
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• pp.191-198
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• 2024

In this paper, we proposes a user management system for efficient operation of the combat system within naval ship. Recently, naval ships have seen performance enhancements through various sensors, features, and continuous system development. This progress in the system has led to an increase in multi-funstion consoles that can manipulate various sensors and features within naval ship, consequently increasing the number of operators for these consoles. Therefore, a user management system that can control and manage multi-function consoles and operators in real-time is necessary for efficient management within naval ship. This paper suggests a user management system that can effectively manage the real-time situation of users accessing multi-function consoles. Additionally, a parallelization method using GPUs to reduce the CPU workload in operating various functions of the combat system is proposed. The proposed user management system has shown a performance improvement where the response time decreased by approximately 82% and the occupancy reduced by approximately 20% compared to the method using CPUs.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1999.10a
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• pp.63-63
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• 1999