• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.9
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• pp.1241-1244
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• 2020

In this paper, we consider a downlink non-orthogonal multiple access system with a base station and N mobile stations, where we assume that instantaneous channel state information (CSI) is available at the base station. A power allocation scheme is proposed to achieve perfect fairness, which means equal data rates for all mobile stations. However, the power allocation scheme using full CSI requires high complexity. Hence, a simple power allocation scheme with low complexity is proposed by using high signal-to-noise power ratio (SNR) approximation. The simple power allocation scheme can achieve perfect fairness only for high SNR. However, it needs only the best CSI and the simple procedure to obtain power allocation coefficients. From simulation results, we show that the simple power allocation scheme provides remarkable fairness performance at high SNR.

• Proceedings of the Korea Technology Innovation Society Conference
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• 2000.05a
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• pp.483-492
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• 2000

In this paper, we explore the economic principle behind the revenue-sharing rule for interconnection charges. First, we assert that firms can collude by splitting tile revenues equally i.e., choosing the revenue-sharing ratio equal to l/2. Also, we characterize the optimal revenue-sharing ratio in a model of horizontal interconnection and discuss the relation between the optimal ratio and the optimal access price.

• Proceedings of the IEEK Conference
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• 2003.07a
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• pp.597-600
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• 2003

Wireless Internet access shows an early-stage market that is entering a period of strong and sustained growth., reaching almost $40 billion in combined related equipment services by 2008 with equipment and services of nearly equal proportion. This explosive development is possible due to the continued growth of two of the most successful markets in history, the internet and mobile telephony. The number of global wireless internet users will incense from approximately 1.9million in 2001 to 1.3billion by 2006. Technological changes are the main factor in the emergence of what is being called the fourth generation of mobile communications.

• Journal of Korea Multimedia Society
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• v.12 no.11
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• pp.1521-1529
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• 2009

There is a serious unfairness problem between upstream and downstream flows of AP in IEEE 802.11 Wireless LAN. This problem is because Wireless LAN's DCF MAC protocol provides AP with equal channel access priority to mobile noded. Also, it makes this problem worse that the TCP's Data segment loss is more effective on throughput than the TCP's ACK segment. In this paper, we first make several simulations to analysis the unfairness in the various point of view and to find reasons of the unfairness. Also, this paper presents AP's scheduling scheme to alleviate the unfairness problem and evaluate the scheme through ns2 simulator.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.10
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• pp.3887-3907
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• 2015

This paper introduces a full duplex single secondary user multiple-input multiple-output (FD-SSU-MIMO) cognitive radio network, where secondary user (SU) opportunistically accesses the authorized spectrum unoccupied by primary user (PU) and transmits data based on FD-MIMO mode. Then we study the network achievable average sum-rate maximization problem under sum transmit power budget constraint at SU communication nodes. In order to solve the trade-off problem between SU's sensing time and data transmission time based on opportunistic spectrum access (OSA) and the power allocation problem based on FD-MIMO transmit mode, we propose a simple trisection algorithm to obtain the optimal sensing time and apply an alternating optimization (AO) algorithm to tackle the FD-MIMO based network achievable sum-rate maximization problem. Simulation results show that our proposed sensing time optimization and AO-based optimal power allocation strategies obtain a higher achievable average sum-rate than sequential convex approximations for matrix-variable programming (SCAMP)-based power allocation for the FD transmission mode, as well as equal power allocation for the half duplex (HD) transmission mode.

• The KIPS Transactions:PartC
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• v.10C no.6
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• pp.793-798
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• 2003

The P2P service is a technology that can share their information with each other who is able to be connected ith a relating program without passing by a server. Since all personal compiters that linked to the internet under the P2P service can opetate as server or a client, they can provide and share both their information and services through the direct connection. Currently, the P2P service is giving an equal privilege to all users for sharing their resources,.Under this situation, a lot of vulnerability against the various sttacks through the Unternet is possoble, more sophisticated security services are necessary. In this paper, We propose and access control schemae using SPKI(Simple Public Key Infrastructure). The scheme designates and access and acces control by providing the certificate to users who request a connection for resource sharing and limits the resource usage of information provider according to the access right that is given to their own rights.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.9
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• pp.1-7
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• 2009

LTE-A (long term evolution advanced) uplink selected SC-FDMA (single carrier frequency division multiple access) to maintain low PAPR for a low price and tiny terminal. Recently, the application of codebook-based preceding to LIE-A uplink is discussed. This paper shows that PAPR can be increased when various preceding schems are applied to the SC-FDMA as an LTE-A uplink. When, considering nonlinear power amplifier model to the transmitter, BER performances of preceded schemes degrade. But equal gain transmission scheme does show very low PAPR. So the link-level performance of EGT is superior to those of any other preceding schemes. Computer simulations also confirm the anticipated link-level performances.

• Ocean and Polar Research
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• v.29 no.1
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• pp.43-53
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• 2007

Recently, controversy over intellectual property rights for protecting genetic resources and traditional knowledge has been emerging. Very active debates and global discussions are being carried out in various international organizations for possible approaches to be taken for these properties, and for the fair and equal sharing of the benefits from these intellectual properties. There is a need to evaluate adopting a sui generis system which is being pushed by developing nations, or adopting a policy which will guaranteee benefit sharing such as sharing royalties from marketing final products, technical transfers, capacity building, and participating in research activities. Also, it is very important to examine the legal issues concerning genetic resources based on Convention on Biological Diversity for the fair and equal sharing of the benefits with developing nations, at the same time assuring developed nations of access to genetic resources.

• Journal of Navigation and Port Research
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• v.45 no.2
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• pp.42-53
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• 2021

The port space can be considered to be the space in which the characteristics of the port city are best expressed. Also, since it acts as a representative gateway along with the airport, it can have a direct impact on the image of the region and country. However, the harbor hinterland has been a refuge during the war in the past, and it has been concentrating on development related to the port industry; hence, it has a poorer residential environment. Therefore, in this study, in order to ensure equal development in space and equal access to basic urban services, urban design directions were suggested for the harbor hinterland based on the concept of an inclusive city'. To this end, through factor analysis, urban planning elements that can be applied to urban design were derived, and through PLS(Partial Least Square)regression analysis, based on the opinions of residents and experts, urban design directions for the port hinterland were presented. The study site was Gamcheon Port, one of the Busan Ports in Korea, the hinterland of Gamcheon Port was a high slope, and the residential environment was relatively poor due to the dense concentration of older residential areas.

• The KIPS Transactions:PartC
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• v.11C no.2
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• pp.219-228
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• 2004

Wireless LAN(wireless Local Area Network) is constructed network environment by radio in indoors or outdoors environment and that to use electric wave or light instead of wire to client such as PC(Personal Computer), notebook, PDA in hub(Hub) in technological side. Now, among IEEE 802.11 WG(Working Group), there is TGf(Task Group F) that develop standard protocol between AP's(Access Point). In this group, proposed IAPP(Inter Access Point Protocol) to secure interoperability between AP producing in different manufacturer, this offers seamless connectivity between STA by sharing Security Context information or Layer 2 forwarding information between AP without passing through re-authentication process when STAs(Station) move by protocol to secure mobility between AP that differ in equal serve network. In this paper, I wish to suggest method that change avenue of communication of message to block information leakage that can occur at security message or WEP Key transmission between above AP, and uses public key to offer wireless area security little more.