• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.7
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• pp.1874-1893
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• 2012

An approach to detect abnormal activities based on reputations created individually by each node is vulnerable to a false accusation since intrusion detection in ad-hoc networks is done in a distributed and cooperative manner. Detection of false accusation is considered important because the efficiency or survivability of the network can be degraded severely if normal nodes were excluded from the network by being considered as abnormal ones in the intrusion detection process. In this paper, we propose an improved reputation-based intrusion detection technique to efficiently detect and manage false accusations in ad-hoc networks. Additionally, we execute simulations of the proposed technique to analyze its performance and feasibility to be implemented in a real environment.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.07a
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• pp.169-169
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• 2004

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.3
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• pp.1260-1283
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• 2019

Low earth orbit (LEO) satellite broadband network is a crucial part of the space information network. LEO satellite constellation design is a top-level design, which plays a decisive role in the overall performance of the LEO satellite network. However, the existing works on constellation design mainly focus on the coverage criterion and rarely take network performance into the design process. In this article, we develop a unified framework for constellation optimization design in LEO satellite broadband networks. Several design criteria including network performance and coverage capability are combined into the design process. Firstly, the quality of service (QoS) metrics is presented to evaluate the performance of the LEO satellite broadband network. Also, we propose a network stability model for the rapid change of the satellite network topology. Besides, a mathematical model of constellation optimization design is formulated by considering the network cost-efficiency and stability. Then, an optimization algorithm based on non-dominated sorting genetic algorithm-II (NSGA-II) is provided for the problem of constellation design. Finally, the proposed method is further evaluated through numerical simulations. Simulation results validate the proposed method and show that it is an efficient and effective approach for solving the problem of constellation design in LEO satellite broadband networks.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.8
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• pp.3749-3768
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• 2018

As one of the most potential types of low-density parity-check (LDPC) codes, CPM-QC-LDPC code has considerable advantages but there still exist some limitations in practical application, for example, the existing decoding algorithm has a low convergence rate and a high decoding complexity. According to the structural property of this code, we propose a new method based on a CPM-RID decoding algorithm that decodes block-by-block with weights, which are obtained by neural network training. From the simulation results, we can conclude that our proposed method not only improves the bit error rate and frame error rate performance but also increases the convergence rate, when compared with the original CPM-RID decoding algorithm and scaled MSA algorithm.

• Journal of the Korea Society of Computer and Information
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• v.16 no.2
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• pp.257-266
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• 2011

Over the society the trial for several systems to be connected with Network has been continued to share information and to make it various. In accordance with such a change, the concept of military warfare conduction has been changing form platform centric warfare in separate combat system based on network centric warfare in network based. We have continuously made an effort that we try to get the goal with efficient system which is linked up with network, but such a study on that one in military system analysis is still slower than the study out of military until now. So this study is searching network influence factor by using military network with application of social network analysis method which is used broadly in the society and the science as well. At this time we search co-relationships between social network and the thing that we can analyse C2 time by effectiveness measurement means. By this study it has value of network influence factor identification for the growing network composition.

• International Journal of Contents
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• v.2 no.2
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• pp.6-9
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• 2006

The style of war in the $21^{st}$ century became digitalized cooperative union tactic, which relies heavily on the system providing real time information. Critical information is provided during the war from sensing to shooting. Therefore, epochal development in observation, reconnaissance (ISR), commanding (C4I) and precision strike (PGM) are necessary. Application of ubiquitous computing and network technologies in national defense is necessary for carrying out with various types of wars in the $21^{st}$ century. Therefore, the author wants to research core technology sector that can be developed and applied in preparation of ubiquitous national defense era. Also plans for applying recent u-Defense technology to the military sector had been suggested. Particularly, the author have suggested plans for utilizing combined future information technologies such as ad-hoc network, RFID for the logistic supply in construction of u-Defense system. By utilizing these information technologies, combat power and strategic capabilities of the military can be enhanced greatly.

• Journal of the Korea Society of Computer and Information
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• v.23 no.10
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• pp.181-188
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• 2018

In this paper, we tried to investigate whether the influence of 'I' in a heterogeneous network of physical network and virtual network can be quantitatively measurable. To do this, we used Networked Community(NC) methodology to devise a concrete model of influence assessment in heterogeneous network. In order to test the model, we conducted an experiment with Donald J. Trump and his surroundings to evaluate the effectiveness of this influence assessment model. Experimentation included the measurement of impacts on the physical and virtual networks, and the impact on the networked community. Using Trump's case, we found that analyzing only one of the two networks can not accurately analyze the impact on others.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.11
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• pp.5425-5448
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• 2018

Wireless sensor network has been widely used in Internet of Things (IoT) applications to support large and dense networks. As sensor nodes are usually tiny and provided with limited hardware resources, the existing multiple access methods, which involve high computational complexity to preserve the protocol performance, is not available under such a scenario. In this paper, we propose an intelligent Medium Access Control (MAC) protocol selection scheme based on machine learning in wireless sensor networks. We jointly consider the impact of inherent behavior and external environments to deal with the application limitation problem of the single type MAC protocol. This scheme can benefit from the combination of the competitive protocols and non-competitive protocols, and help the network nodes to select the MAC protocol that best suits the current network condition. Extensive simulation results validate our work, and it also proven that the accuracy of the proposed MAC protocol selection strategy is higher than the existing work.

• Proceedings of the Korean Information Science Society Conference
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• 2012.06b
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• pp.80-82
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• 2012

전쟁수행 패러다임이 변화하면서 NCW 환경에서 발생하는 네트워크 파워를 측정하려는 많은 연구들이 수행되고 있다. 그러나 기존의 연구는 현실의 전장환경내 구축되어 있는 C2 체계의 네트워크 구조와 각 시스템간의 상호운용성 요소를 평가에 반영하지 못하고 있다. 따라서 본 연구에서는 최근 다양한 분야에서 활용되고 있는 소셜 네트워크 분석 기법을 적용하여 다수의 지휘통제체계에 의해 구축되는 네트워크 구조를 평가할 수 있는 알고리즘을 제안한다. 제안한 알고리즘을 통해 진화하는 군 C2 체계의 네트워크 구조를 대상으로 평가 결과를 분석해보았으며, 연결성에 근거한 네트워크 구조에 상호운용성 가치를 반영함으로써 보다 실질적인 네트워크 파워를 제시함에 그 목적이 있다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.3
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• pp.916-937
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• 2023

Most of the existing Distributed Denial-of-Service mitigation schemes in Software-Defined Networking are only implemented in the network domain managed by a single controller. In fact, the zombies for attackers to launch large-scale DDoS attacks are actually not in the same network domain. Therefore, abnormal traffic of DDoS attack will affect multiple paths and network domains. A single defense method is difficult to deal with large-scale DDoS attacks. The cooperative defense of multiple domains becomes an important means to effectively solve cross-domain DDoS attacks. We propose an efficient multi-domain DDoS cooperative defense mechanism by integrating blockchain and SDN architecture. It includes attack traceability, inter-domain information sharing and attack mitigation. In order to reduce the length of the marking path and shorten the traceability time, we propose an AS-level packet traceability method called ASPM. We propose an information sharing method across multiple domains based on blockchain and smart contract. It effectively solves the impact of DDoS illegal traffic on multiple domains. According to the traceability results, we designed a DDoS attack mitigation method by replacing the ACL list with the IP address black/gray list. The experimental results show that our ASPM traceability method requires less data packets, high traceability precision and low overhead. And blockchain-based inter-domain sharing scheme has low cost, high scalability and high security. Attack mitigation measures can prevent illegal data flow in a timely and efficient manner.