• ETRI Journal
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• v.38 no.6
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• pp.1153-1162
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• 2016

This paper addresses the resource allocation (RA) problem in multi-cell cognitive radio networks. Besides the interference power threshold to limit the interference on primary users PUs caused by cognitive users CUs, a proportional fairness constraint is used to guarantee fairness among multiple cognitive cells and the impact of imperfect spectrum sensing is taken into account. Additional constraints in typical real communication scenarios are also considered-such as a transmission power constraint of the cognitive base stations, unique subcarrier allocation to at most one CU, and others. The resulting RA problem belongs to the class of NP-hard problems. A computationally efficient optimal algorithm cannot therefore be found. Consequently, we propose a suboptimal RA algorithm composed of two modules: a subcarrier allocation module implemented by the immune algorithm, and a power control module using an improved sub-gradient method. To further enhance algorithm performance, these two modules are executed successively, and the sequence is repeated twice. We conduct extensive simulation experiments, which demonstrate that our proposed algorithm outperforms existing algorithms.

• Journal of Advanced Navigation Technology
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• v.10 no.1
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• pp.34-40
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• 2006

Multiple wireless devices in wired and wireless heterogeneous networks communicate with counterparts via a single Access Point (AP). In this case, the AP becomes a bottleneck of the network, therefore buffer overflows occur frequently and result in TCP performance degradation. In this paper, the new algorithm that prevents buffer overflows at AP and enhances TCP fairness is proposed. Depending on the buffer usage of AP, the new algorithm adaptively controls each TCP senders' transmission rate, prevents buffer overflows and thus guarantees improved TCP fairness. It is proved that the algorithm makes better of TCP throughput and fairness by preventing buffer overflows.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.5
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• pp.826-832
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• 2015

In wireless networks, it is important to guarantee the energy efficiency and receiver fairness for satisfying service provider and customer at the same time. In this paper, we propose a resource allocation algorithm which improves energy efficiency as well as receiver fairness based on optimization techniques. In the proposed algorithm, subchannel and power are allocated to receivers iteratively in the consideration of channel state information, amount of dissipated power, and receiver rate, in order to improve energy efficiency and receiver fairness. Through simulation, we show the effectiveness and superiority of the proposed algorithm in terms of energy efficiency and receiver fairness.

• Journal of the Korean Society of Clothing and Textiles
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• v.45 no.5
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• pp.892-906
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• 2021

This study explores the effects of providing information on the price fairness perception and intention of continuous use in an online fashion platform, given a price difference due to AI algorithm pricing. We investigated the moderating roles of price inequality (loss vs. gain) and technology insecurity. The experiments used four stimuli based on price inequality (loss vs. gain) and information provision (provided or not) on price inequality. We developed a mock website and offered a scenario on the product presentation based on an AI algorithm pricing. Participants in their 20s and 30s were randomly allocated to one of the stimuli. To test the hypotheses, a total of 257 responses were analyzed using Process Macro 3.4. According to the results, price fairness perception mediated between information provision and continuous use intention when consumers saw the price inequality as a gain. When the consumers perceived high technology insecurity, information provision affected the intention of continuous use mediated by price fairness perception.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.3A
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• pp.247-260
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• 2007

This paper solves the problem of finding a suitable sub-channel and power joint allocation method for multiple users in 802.16e OFDMA/TDD cellular systems. The joint allocation is thatfirstly the sub-channel is allocated to the users and then suitable power is allocated. We propose a FASA (Fairness insured Aggressive Sub-channel Allocation) algorithm which is a dynamic channel allocation algorithm considering all users' channel state information conditionally to maximize fairness and throughput. The improved CHC algorithm, which is dynamic power allocation algorithm, is also proposed in this paper The Improved CHC algorithm collects the extra of the downlink transmit power and then re-allocates it to other users. Simulation results show that the proposed improved CHC algorithm additionally increases the fairness and sector throughput.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.3 no.4
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• pp.385-398
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• 2009

This paper aims to find a suitable solution to joint allocation of sub-channel and transmit power for multiple users in an IEEE 802.16e OFDMA/TDD cellular system. We propose the FASA (Fairness insured Aggressive Sub-channel Allocation) algorithm, which is a dynamic channel allocation algorithm that considers all of the users' channel state information conditionally in order to maximize throughput while taking into account fairness. A dynamic power allocation algorithm, i.e., an improved CHC algorithm, is also proposed in combination with the FASA algorithm. It collects the extra downlink transmit power and re-allocates it to other potential users. Simulation results show that the joint allocation scheme with the improved CHC power allocation algorithm provides an additional increase of sector throughput while simultaneously enhancing fairness. Four frames of time delay for CQI feedback and scheduling are considered. Furthermore, by addressing the difference between uplink and downlink scheduling in an IEEE 802.16e OFDMA TDD system, we can employ the uplink channel information directly via channel sounding, resulting in more accurate uplink dynamic resource allocation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.6B
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• pp.586-592
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• 2002

In this paper, new channel scheduling algorithms which reduce transmission delay caused by wireless network are proposed in AMC/TDM wireless data communication. The concept of the Proposed algorithms is based on the proportional fairness, M-LWDF, and performance-guaranteeing algorithm proposed by Xin Liu. The proposed algorithm can be applied to QoS guaranteeing services as well as best-effort services. Simulation results show that new algorithm reduced transmission delay upto 11.5% in case of proportional fairness algorithm and also decreased transmission delay unto 9% in case of M-LWBF algorithm.

• ETRI Journal
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• v.31 no.5
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• pp.481-488
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• 2009

This paper proposes a new multiuser scheduling algorithm that can simultaneously support a variety of different quality-of-service (QoS) user groups while satisfying fairness among users in the same QoS group in MIMO broadcast channels. Toward this goal, the proposed algorithm consists of two parts: a QoS-aware fair (QF) scheduling within a QoS group and an antenna trade-off scheme between different QoS groups. The proposed QF scheduling algorithm finds a user set from a certain QoS group which can satisfy the fairness among users in terms of throughput or delay. The antenna trade-off scheme can minimize the QoS violations of a higher priority user group by trading off the number of transmit antennas allocated to different QoS groups. Numerical results demonstrate that the proposed QF scheduling method satisfies different types of fairness among users and can adjust the degree of fairness among them. The antenna trade-off scheme combined with QF scheduling can improve the probability of QoS-guaranteed transmission when supporting different QoS groups.

• Journal of KIISE:Information Networking
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• v.29 no.5
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• pp.524-532
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• 2002

With the recent rapid progress of Internet, the higher speed network is needed to support the exploration of ambient information from text-based to multimedia-based information. Also, demands for additional Layer 3 routing technique, such as Network Address Translator (NAT) and Firewall, are required to solve a limitation of a current Internet address space and to protect the interior network from the exterior network. However, current router-based algorithms do not provide mechanisms to solve the congestion and fairness problems, while supporting the multimedia services and satisfying the user requirements. In this paper, to solve these problems, a new active queue management, called MFRED (Multiple Fairness RED) algorithm, is proposed. This algorithm can efficiently reduce the congestion in a router or gateway based on the Layer 3 routing technique, such as NAT. This algorithm can improve the fairness among TCP-like flows and unresponsive flows. It also works well in fairly protecting congestion-sensitive flows, i.e. fragile TCP, from congestion-insensitive or congestion-causing flows, i.e. robust TCP.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.39 no.4
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• pp.188-200
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• 2002

The WRR scheduling algorithm is widely used in ATM networks due to its simplicity and the low cost of hardware implementation. It guarantees minimum cell rate according to the weight of each queue. The fairness is a important factor for ABR service. That is, scheduling algorithm allocates network resources fairly to each VC. However, WRR algorithm shows worse performance on bursty traffic. Because it schedules input traffics according to predetermined weight, it can not satisfies fairness criteria, MCR plus equal share and Maximum of MCR or Max-Min share, defined by ATM Forum TM 4.1 specification. The Nabeshima et al algorithm is not adapt to network status rapidly because it is not compensate the weights of unused bandwidth to VCs and assign the unused bandwidth to VCs by RR method. In this paper, we propose a scheduling algorithm for satisfying the two fairness criteria, MCR plus equal share and Maximum of MCR or Max-Min share, among the six criteria defined by ATM Forum TM 4.1 specification. The WRR, Nabeshima et al, and the proposed scheduling algorithms are compared with respect to fairness and convergence time throughout experimental simulation. According to the simulation results, the proposed algorithm shows higher fairness and more rapid convergence than other algorithms.