• Journal of Korean Society of Transportation
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• v.29 no.1
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• pp.81-93
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• 2011

This research deals with the multi-modal continuous network design problem to resolve the transportation policy problems for constructing and operating transportation facilities with considering the mutual decision-making process between transportation operator and user in the multi-modal network. Particularly, in the consideration of changes in travel pattern between transport modes due to the changes in transportation policy, road network for passenger car and transit network for public transportation are considered together. In the development of network design model, more rational Stackelberg equilibrium(cooperative game) rather than more general Nash equilibrium(non-cooperative game) approach is used and sensitivity analysis considering transport mode is used. A multi-modal continuous network design model in this study is developed for the arbitrary continuous network design parameters(${\epsilon},\hat{\epsilon},p$) of transportation policy decisions. As examples of application and evaluation for these design parameters, the developed model is applied to calculate 1)the optimal capacity of road link in the road transport policy, 2)the optimal frequency of transit line in public transport policy and 3)the optimal modal split in transport modal share policy.

• Journal of Communications and Networks
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• v.11 no.2
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• pp.196-206
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• 2009

Over the last five years, relaying or multihop techniques have been intensively researched as means for potentially improving link performance of wireless networks. However, the data rates of relays are often limited because they cannot transmit and receive on the same frequency simultaneously. This limitation has come to the attention of researchers, and recently a number of relay techniques have been proposed specifically to improve the data efficiency of relaying protocols. This paper surveys transmission protocols that employ first single relays, then multiple relays and finally multiple antenna relays. A common feature of these techniques is that novel signal processing techniques are required in the relay network to support increased data rates. This paper presents results and discussion that highlight the advantages of these approaches.

• 한국정보통신설비학회:학술대회논문집
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• 2009.08a
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• pp.337-343
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• 2009

Information theory is one field of the applied mathematics quantitating the data in order to store data as many as in the medium or communicate through channel. it was released on the Shannon's paper, in 1948. With basis on this paper, It has been achieved dramatically development for communication, signal processing, and date procedure and transmission in the network In this paper, the basic concept of information theory is described through dealing with contents about meaning of information, entropy, and channel capacity. It is also handled how information theory is applied to the fields of sensor network, relay channel, MIMO system, and others.

• Journal of the Korean housing association
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• v.18 no.1
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• pp.103-112
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• 2007

This paper attempts to solve the problems what is Making Livable City for and how to implement their scheme in the future. The purpose of this article is two. First, it is a examination of the background and main concept of Making Liviable City that was proposed last year end and compare with similar urban development strategies. Second, it is proposed direction and scheme that is workable to implement in local community level especially, throuth the participants' role for Making Livable City. It is concluded that is needed to develop indicator for Livable City, reinforcement of administrative capacity, formation of political mood for paticipation, and enactment of Act of Making Livable City. Impications are discussed for significance of mutual cooperative endeavour and partnerships between participants in decision-making.

• Journal of Communications and Networks
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• v.10 no.2
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• pp.127-136
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• 2008

For mobile wireless systems with full frequency reuse, co-channel interference near the cell coverage boundaries has a significant impact on the signal reception performance. This paper addresses an approach to efficiently mitigate the effect of downlink co-channel interference when multi-antenna terminals are used in cellular environments, by proposing a signal detection strategy combined with a system-level coordination for dynamic frequency reuse. We demonstrate the utilization of multi-antennas to perform spatial demultiplexing of both the desired signal and interfering signals from adjacent cells results in significant improvement of spectral efficiency compared to the maximal ratio combining (MRC) performance, especially when an appropriate frequency reuse based on the traffic loading condition is coordinated among cells. Both analytic expressions for the capacity and experimental results using the adaptive modulation and coding (AMC) are used to confirm the performance gain. The robustness of the proposed scheme against varying operational conditions such as the channel estimation error and shadowing effects are also verified by simulation results.

• Proceedings of the KIEE Conference
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• 2000.11a
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• pp.3-5
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• 2000

It has been the paradigm of game theory that more than two utilities compete and determine the price and amount of dispatch. In order for this theory to be available on real power system, it is necessary to consider the transmission costs as well as the generation costs. In addition Independent System Operator(ISO) should be able to mitigate the congestion, recover the transmission costs and provide information for long-term capacity investment by devising reasonable pricing schemes for the transmission services. Generators also have to take the transmission costs into account when building the bidding strategies. This paper proposes an approach to analyzing the profit maximizing game considering the transmission cost in a competitive electricity market.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.6
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• pp.2649-2669
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• 2020

In this paper, we analyze the secrecy performance of single-input multiple-output (SIMO) relay systems over κ-μ shadowed fading channels. Based on considering relay model employing decode-and-forward (DF) protocol, two security evaluation metrics, namely, secure outage probability (SOP) and probability of strictly positive secrecy capacity (SPSC) are studied, for which closed-form analytical expressions are derived. In addition, Monte Carlo results prove the validity of the theoretical derivation. The simulation results confirm that the factors that enhance the security include large ratio of (μ_D, μ_E), (m_D, m_E), (L_D, L_E) and small ratio of (k_D, k_E) under the high signal-to-noise ratio regime.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.1
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• pp.260-279
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• 2015

In this paper, we investigate physical layer security for multiple decode-and-forward (DF) relaying underlay cognitive radio networks (CRNs) with fixed transmit power at the secondary network against passive eavesdropping attacks. We propose a simple relay selection scheme to improve wireless transmission security based on the instantaneous channel information of all legitimate users and the statistical information about the eavesdropper channels. The closed-form expressions of the probability of non-zero secrecy capacity and the secrecy outage probability (SOP) are derived over independent and non-identically distributed Rayleigh fading environments. Furthermore, we conduct the asymptotic analysis to evaluate the secrecy diversity order performance and prove that full diversity is achieved by using the proposed relay selection. Finally, numerical results are presented to verify the theoretical analysis and depict that primary interference constrain has a significant impact on the secure performance and a proper transmit power for the second transmitters is preferred to be energy-efficient and improve the secure performance.

• Journal of IKEEE
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• v.22 no.3
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• pp.570-577
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• 2018

With the increasing number of network nodes, traditional client/server node selection mechanisms are under tremendous pressure. In order to select efficient cooperative nodes in a highly dynamic P2P network topology, this article uses greedy algorithm to translate the overall optimization into multiple local optimal problems, and to quickly select service nodes. Therefore, the service node with the largest comprehensive capacity is selected to reduce the transmission delay and improve the throughput of the service node. The final simulation results show that the node selection strategy based on greedy algorithm can effectively improve the overall performance of P2P streaming media system.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.67 no.1
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• pp.37-41
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• 2018

In this paper, the ESS(Energy Storage System) is interconnected in order to reduce the maximum load in the distribution system and the target location of the ESS is set to be close to the rated voltage. We also applied the weights to nodes with large capacity and number of customers in the system. In the future, the interconnected location of the ESS was determined until 2029 in consideration of the load increase rated of the system. We propose a cooperative decision algorithm of interconnected location of ESS for Power Distribution System.