• Journal of Internet Computing and Services
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• v.22 no.5
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• pp.1-8
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• 2021

Small-cells in heterogeneous networks are one of the important technologies to increase the coverage and capacity in 5G cellular networks. However, due to the randomly arranged small-cells, co-tier and cross-tier interference increase, deteriorating the system performance of the network. In order to manage the interference, some channel management methods use fractional frequency reuse(FFR) that divides the cell coverage into the inner region(IR) and outer region(OR) based on the distance from the macro base station(MBS). However, since it is impossible to properly measure the distance in the method with FFR, we propose a new interference aware FFR(IA-FFR) method to enhance the system performance. That is, the proposed IA-FFR method divides the MUEs and SBSs into the IR and OR groups based on the signal to interference plus noise ratio(SINR) of macro user equipments(MUEs) and received signals strength of small-cell base stations(SBSs) from the MBS, respectively, and then dynamically assigns subchannels to MUEs and small-cell user equipments. As a result, the proposed IA-FFR method outperforms other methods in terms of the system capacity and outage probability.

• Journal of the Korean Society of Food Culture
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• v.36 no.6
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• pp.542-554
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• 2021

Institutional foodservice is a type of meal provided to workers in industry and affects the health and psychological wellbeing of workers and productivity. Thus, research on customer satisfaction with institutional foodservice is important. In addition to food industry and food culture developments, the requirements of institutional foodservice customers are diversifying due to COVID-19. Therefore, the purpose of this study was to identify factors that affect customer satisfaction with institutional foodservice using a user-based approach. In this study, the quality of institutional foodservice was defined using customer satisfaction or dissatisfaction, and by using in-depth interview and open coding (a qualitative research method), we derived qualities of institutional foodservice from the user's perspective and compared these with those of previous studies. This study is meaningful as the quality of institutional foodservice was analyzed using a user-based approach, in-depth interview, and open coding and compares results with those of previous studies.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.31 no.3
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• pp.341-351
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• 2021

Recently, user-driven privacy control technology, such as distributed ID management, has been gaining attention. However, the existing blockchain-based access control studies have not provided a sufficient level of privacy control method to users. This paper proposes a method that combines permissioned blockchain technology and a recent privacy control standard. To allow users to participate in privacy control, a token-based user access control service that conforms to the UMA2 standard was applied to the blockchain dApp. By combining the blockchain and UMA2, the proposed method provides a user-centered privacy control function that the existing blockchain could not provide. In addition, we solved the problem of privacy, security, and availability of entities, which are the disadvantages of UMA2.

• Knowledge Management Research
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• v.23 no.2
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• pp.83-98
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• 2022

The current study investigated the effect of user interface design on metaverse user's objective task performance, perceived usefulness, presence, and enjoyment. Using a 2 × 2 within-subject repeated measure experimental design, we found that users perceived the interface to be significantly more useful when additional visual cues existed and performed better for the given task. Additionally, a repeated-measure mediation analysis revealed that the effect of richer information in the interface on users' enjoyment as a function of need satisfaction was mediated by perceived usefulness. Theoretical and practical implication are derived from the result of the current study.

• Information Systems Review
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• v.22 no.2
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• pp.77-99
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• 2020

Smart speaker is a device that provides an interactive voice-based service that can search and use various information and contents such as music, calendar, weather, and merchandise using artificial intelligence. Since AI technology provides more sophisticated and optimized services to users by accumulating data, early smart speaker manufacturers tried to build a platform through aggressive marketing. However, the frequency of using smart speakers is less than once a month, accounting for more than one third of the total, and user satisfaction is only 49%. Accordingly, the necessity of strengthening the user experience of smart speakers has emerged in order to acquire a large number of users and to enable continuous use. Therefore, this study analyzes the user experience of the smart speaker and proposes a method for enhancing the user experience of the smart speaker. Based on the analysis results in two stages, we propose ways to enhance the user experience of smart speakers by model. The existing research on the user experience of the smart speaker was mainly conducted by survey and interview-based research, whereas this study collected the actual review data written by the user. Also, this study interpreted the analysis result based on the smart speaker user experience dimension. There is an academic significance in interpreting the text mining results by developing the smart speaker user experience dimension. Based on the results of this study, we can suggest strategies for enhancing the user experience to smart speaker manufacturers.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.1
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• pp.119-131
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• 2013

With the explosive growth of computer networks, many remote service providing servers and multi-server network architecture are provided and it is extremely inconvenient for users to remember numerous different identities and passwords. Therefore, it is important to provide a mechanism for a remote user to use single identity and password to access multi-server network architecture without repetitive registration and various multi-server authentication schemes have been proposed in recent years. Recently, Tsaur et al. proposed an efficient and secure smart card based user authentication and key agreement scheme for multi-server environments. They claimed that their scheme satisfies all of the requirements needed for achieving secure password authentication in multi-server environments and gives the formal proof on the execution of the proposed authenticated key agreement scheme. However, we find that Tsaur et al.'s scheme is still vulnerable to impersonation attack and many logged-in users' attack. We propose an extended scheme that not only removes the aforementioned weaknesses on their scheme but also achieves user anonymity for hiding login user's real identity. Compared with other previous related schemes, our proposed scheme keeps the efficiency and security and is more suitable for the practical applications.

• Journal of Digital Convergence
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• v.10 no.3
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• pp.105-111
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• 2012

Internet Protocol Television (IPTV) through broadband cable network is a subscriber-based system which consists of software and set-top box. However, a weakness for the current IPTV system is the lack of security between users and CAS. This paper proposes a user authentication protocol at STB, which limits the service by the user-valued attribute to prevent illegal IPTV users. User attribute values change the order with bit form according to the certain rule, and apply to one-way hash function and Diffie-Hellman's elliptic curve key-exchange algorithm. The proposed protocol is able to improve on user authentication and computation. Also, each user generates an authentication message by smart card and receives various services based on the user-valued attribute.

• The Journal of Information Systems
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• v.27 no.3
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• pp.161-180
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• 2018

Purpose One of the success factors of information system projects is to reduce requirements uncertainty through user engagement. So, in many recent IS development environment, a business analyst or business analysts are positioned between users and developers to drive user engagement to reduce requirements uncertainty. But, there are few studies that research about the competencies of business analysts for training and staffing. So, this study analyzed which underlying and practical competencies that positively influence user engagement are required. Design/methodology/approach The level of underlying and practical competencies required for business analysts and the level of user enagement in the IS development environment are collected through the survey. And, the causal relationship between the construct concepts which are underlying competencies, practical competencies and the user participation is analzed through the PLS analysis. Findings The results of this study show that the practial competencies of business analysts that positively have a significant impact on user engaement were studied as requirements development skills. Additionally, the underlying competencies of business analysts which have a significant impact on requirements development skills were examined as business knowledge and interaction skills rather than technical knowledge and communication skills.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.10
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• pp.5100-5119
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• 2018

Most of existing privacy-preserving multi-authorities attribute-based encryption schemes (PP-MA-ABE) only considers the privacy of the user identity (ID). However, in many occasions information leakage is caused by the disclosing of his/her some sensitive attributes. In this paper, we propose a collusion-resisting ciphertext-policy PP-MA-ABE (CRPP-MACP-ABE) scheme with hiding both user's ID and attributes in the cloud storage system. We present a method to depict anonymous users and introduce a managerial role denoted by IDM for the management of user's anonymous identity certificate ($AID_{Cred}$). The scheme uses $AID_{Cred}$ to realize privacy-preserving of the user, namely, by verifying which attribute authorities (AAs) obtain the blinded public attribute keys, pseudonyms involved in the $AID_{Cred}$ and then distributes corresponding private keys for the user. We use different pseudonyms of the user to resist the collusion attack launched by viciousAAs. In addition, we utilize IDM to cooperate with multiple authorities in producing consistent private key for the user to avoid the collusion attack launched by vicious users. The proposed CRPP-MACP-ABE scheme is proved secure. Some computation and communication costs in our scheme are finished in preparation phase (i.e. user registration). Compared with the existing schemes, our scheme is more efficient.

• Journal of Information Technology Applications and Management
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• v.31 no.3
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• pp.93-104
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• 2024

This study conducts an in-depth analysis of user reviews from three leading metaverse platforms - Minecraft, Roblox, and Zepeto - using advanced topic modeling techniques to uncover key factors for business success. By examining a substantial dataset of user feedback, we identified and categorized the main themes and concerns expressed by users. Our analysis revealed that common issues across all platforms include technical functionality problems, user engagement and interest, payment concerns, and connection difficulties. Specifically, Minecraft users highlighted the importance of adventure and creativity, Roblox users expressed significant concerns about security and fraud, and Zepeto users focused heavily on the fairness of the in-game economy. The findings suggest that for metaverse platforms to achieve sustained success, they must prioritize the resolution of technical issues, enhance features that foster user engagement, ensure reliable connectivity, and address platform-specific concerns such as security for Roblox and payment fairness for Zepeto. These insights provide valuable guidance for developers and business strategists, emphasizing the need for robust technical infrastructure, engaging and diverse content, seamless user access, and transparent and fair economic systems. By addressing these key areas, metaverse platforms can improve user satisfaction, build a loyal user base, and secure long-term success in an increasingly competitive market.