• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.6
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• pp.1029-1036
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• 2021

Recently it has been proposed that lossless 2-user non-orthogonal multiple access (NOMA) can be implemented without successive interference cancellation (SIC) via correlated superposition coding (CSC). However only the 2-user case was considered. Thus this paper proposes a lossless 3-user non-SIC NOMA scheme. This can be achieved via the 3-user CSC scheme. Simulations show that the lossless 3-user non-SIC NOMA scheme can be implemented over power allocation ranges of user-fairness.

• 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.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.12A
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• pp.1291-1297
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• 2004

In this paper, the new scheduling algorithm that supports the maximization of system throughput and the proportional fairness among non-real time traffic users is proposed in OFDMA wireless mobile communication systems. The concept of the proposed algorithm is based on the proportional fairness algorithm, which is deployed in 3GPP2, and sorting method. The proportional fairness algorithm is adapted to allocate the number of subcarrier per user. A sorting method is contributed to the maximization of system throughput in the practical allocation of subcarrier per user. Simulation results show that new algorithm had better performance than the max rate rule in case of fairness, higher throughput than the scheduling algorithm without sorting method. Even though the system throughput of the proposed algorithm is almost same with the iteration scheme using subcarrier swapping method between users, the computational time of the former is reduced up to 3 times than the latter.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.7B
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• pp.613-627
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• 2004

In this paper, we propose an Aggregate Fairness Maker (ARM) required for an Edge router to improve fairness of throughput among the flows of Assured Service in DiffServ with different round trip time (RTT) and we propose a user flow Three Color Marker (uf-TCM) as a flow marker that marks packets from the flow as green, yellow, or red. A yellow packet is the packet that consumes loss token in uf-TCM as well as that is demoted green packet in AM due to disobey the aggregate traffic profile. The proposed AFH promotes yellow packet to green packet or demotes green packet to yellow packet through the fair method without per-flow management, and it improves the feirness of throughput among the flows as well as link utilization. A yellow packet and a red packet have the same drop precedence at Core Router in our scheme. So we can use the RIO buffer management scheme. We evaluated the performance of our proposed AFM and the REDP Marker that was proposed to improve fairness without per-flow management. Simulation results show that, compared with the REDP marker, proposed AFM can improve performance of throughput fairness among the flows with different RTT and link utilization under the over-provisioning, exact-provisioning, and under-provisioning network environments at Multiple DiffServ domains as well as at Single DiffServ domain.

• Journal of Electrical Engineering and Technology
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• v.10 no.6
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• pp.2406-2412
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• 2015

Multi-user multi-input multi-output (MU-MIMO) system has attracted the 4^th generation wireless network as one of core technique for performance enrichment. In this system rate control is a challenging problem and another problem is optimization. Proper scheduling can resolve these problems by deciding which set of user and at which rate the users send their data. This paper proposes a new multi-parameter based scheduling (MPS) for downlink multi-user multiple-input multiple-output (MU-MIMO) system under space-time block coding (STBC) transmissions. Goal of this MPS scheme is to offer improved link level performance in terms of a low average bit error rate (BER), high packet delivery ratio (PDR) with improved resource utilization and service fairness among the user. This scheme allows the set of users to send data based on their channel quality and their demand rates. Simulation compares the MPS performance with other scheduling scheme such as fair scheduling (FS), normalized priority scheduling (NPS) and threshold based fair scheduling (TFS). The results obtained prove that MPS has significant improvement in average BER performance with improved resource utilization and fairness as compared to the other scheduling scheme.

• Journal of Advanced Navigation Technology
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• v.7 no.1
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• pp.59-71
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• 2003

The channel scheduler is suggested the radio resource management method in order to provide service with guaranteeing fairness and throughput to the users who use limited wireless channel. Proportional fairness scheduling algorithm is the channel scheduler used in the AMC(Adaptive Modulation and Coding)/TDM system, and this algorithm increases the throughput considering the user's time fairness. In this paper is suggested the channel scheduler combining CDM scheme available in AMC/TDM/CDM system. Unlike the system which only uses TDM which provide the only one user at the same slot, this scheduler can service a lot of users since this uses the CDM scheme with multi-cord channel. At every moment, allocation of transmission power to multi-channel users is problematic because of CDM scheme. In this paper, we propose a water-filling scheduling algorithm to solve the problem. Water-filling fairness(WF2) scheduling algorithm watches the average channel environment. So, this modified method guarantees fairness for each user in terms of power and service time.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.1
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• pp.37-44
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• 2016

It is important that using of efficient radio resource because of deficiency spectrum problem, so that related to this problem many researches are have proceeded. To solve this problem, Cognitive Radio(CR) was suggested. The channels are allocated to the secondary users when the primary users don't use the channels, and unfairness of secondary users can be serious problem and channel quality of multichannel can be different due to the different traffic pattern of primary users. In this paper, we propose MAC prtocol both of the user's fairness and channel quality in CR networks. Simulation results show the comparison with CR MAC protocols.

• The Journal of Information Systems
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• v.17 no.1
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• pp.1-22
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• 2008

As National Education Information Systems (NEIS) is supposed to broadly introduced all over the country, we need to understand factors that would affect its successful use. Studies regarding the NEIS have been made in terms of a social issue according to its introduction and use, however there has been only little research made in terms of the use of the system so far. Therefore, this study aims to investigate the factors that would have effect on a successful use of the NEIS. A research model of the study is based on the extended DeLone and McLean's information systems success model with two characteristics of computer self-efficacy and perceived fairness. Based on the survey data from 168 subjects, the present study performs SEM analysis with PLS. The results show that perceived usefulness and computer self-efficacy improves the user satisfaction. However, the user' satisfaction does not cause system characteristics- system quality, information quality, service quality -and perceived fairness not effect. The study provides characteristics which can effectively and smoothly introduce the NEIS for its successful use on the upcoming full scale execution on the NEIS.

• Journal of the Korea Safety Management & Science
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• v.12 no.2
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• pp.89-97
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• 2010

The most important concern in the internet service organizations in competitive market circumstances is to focus on formation and maintenance of continuous relationship with customers. The purpose of this study is to verify the effect of perception of the fairness - procedural fairness for recovery, interactional fairness, fairness for reward on customer's satisfaction and trust, behavior when the internet service company failed to service such as disclosure of personal information. This study aims to apply justice theories to service recovery. As a result, first, the customer's perceived justice had a significant effect on the customer satisfaction and trust in service recovery. Second, the customer's satisfaction positive effect on trust. Third, customer's satisfaction formed by service recovery had a effect on the customer's behavior such as continuous usage intention. Therefore, this study was reveal how the extent of justice perception felt by customers in the service recovery process, causes positive causation relationship which affect customer behavior intention.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.4
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• pp.794-799
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• 2015

To manage cell outage problem in indoor wireless communication systems, we should resolve the problem of abrupt network failure quickly. In this paper, we propose a near-optimal cell outage management (NoCOM) scheme to support seamless services to users. In consideration of system throughput, user fairness, and the guarantee of QoS simultaneously, the NoCOM scheme finds the solution of subchannel and power allocations using a non-convex optimization technique and allocates radio resources to users iteratively. Through intensive simulations, we verify the outstanding performances of the proposed NoCOM scheme with respect to the average cell capacity, user fairness, and computational complexity.