• Convergence Security Journal
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• v.13 no.1
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• pp.19-24
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• 2013

MANET has a highly dynamic topology because it consists of only mobile nodes. Various attacks using these characteristics exist. Among them, damage of the attacks based flooding such as DoS or DDos is large and traceback of the attack node is not easy. It is because route information by moving of intermediate nodes which pass the data changes frequently. In this paper, we propose table-based traceback technique to perform efficient traceback although route information by moving of nodes changes frequently. Cluster head manages route management table in order to form cluster status table and network topology snapshot for storing the location information of mobile nodes when cluster member nodes change. Also, bloom filter is used to reduce the amount of storing route information. The performance of the proposed technique is confirmed through experiment.

• The KIPS Transactions:PartC
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• v.14C no.4
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• pp.359-364
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• 2007

Current researches on the overlay multicast mechanism in the mobile ad hoc network (MANET) maintain the network topology information of the dynamically changing MANET, which may cause severe overhead. In this paper, we propose a new overlay multicast mechanism, the region-based overlay multicast in MANET(ROME), using the geometric locations of group members. In ROME, the physical topology is divided into small regions and the scope of location updates of group members is limited to a single region. ROME provides scalability by using the coordinate of the center point of a destination region as the destination of a data packet instead of the list of member addresses of that region. Our simulation results show that ROME gives better performance in terms of the packet overhead than other schemes.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.5
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• pp.709-716
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• 2011

Recently, there are many difficult for maintenance in the power in established sensor networks. In order to solve this problems, the power development has been interested using vibration in MEMS that insert the MEMS oscillator. In this paper, we propose the MEMS system with Duffing equation to generate vibration signal that can be use power signal in MEMS and confirm and verify the chaotic behaviors in vibration signal of MEMS by computer simulation. As a verification methods, we confirm the existence of period motion and chaotic motion by parameter variation through the time series, phase portrait, power spectrum and poincare map.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.11
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• pp.4543-4552
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• 2010

A leader is a special process who roles as the coordinator within multiple processes of a group. In a distributed system, leader election is the procedure of electing a coordinator. This is a very important issue for building fault-tolerant distributed systems. When two normal mobile ad hoc networks are merged, there are two leaders. This violates the safety property, so a mechanism to detect and handle are required. In mobile ad hoc distributed computing system, we propose a leader competition protocol and to prove the temporal logic to it. This solution is based on the group membership detection algorithm.

• Convergence Security Journal
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• v.18 no.1
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• pp.3-11
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• 2018

The emerging field of Science of Security (SoS) is a new paradigm that emerged in the field of security as a research field that applied the scientific approach to cyber security. It is a direction to study the formal model and automation field to secure the security of such a network environment in the present that dynamic change of complex, large scale network environment and a lot of protocol and mechanism environment exists. Therefore, this study analyzes the latest cyber security research trends such as SoS and examines the research trends of advanced countries to examine a new approach to cyber security development direction in Korea. We also analyze the current state of domestic scientific research on the scientific security research methods for various cyber security paradigms and present directions for revitalizing domestic cyber security.

• Proceedings of the Korea Contents Association Conference
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• 2007.11a
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• pp.60-64
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• 2007

Increasing using multimedia services as VoIP, Video conference, DMB, IPTV, etc, it is necessary to increase network traffics and develop the mechanism about a flow control for real time traffic transmission. In order to transfer realtime multimedia data, the transfer rate can be control on network state data measuring packet losses of a receiver and delay time of packets through getting periodical feedback RTP/RTCP packet. This paper describes using efficiant flow control on multicast that can reduce errors according to getting feedback tranfer delay and proposes the mechanism that can adapt dynamic change of network. In simulation, the transfer rate can efficiently be control on dynamic change of network and it makes the maximum of the use of a bandwidth and the minimum of packet losses.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.11B
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• pp.772-783
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• 2005

In this paper, we propose an effective multicasting protocol in wireless ad-hoc networks. Conventional wired and wireless network multicast protocols do not perform well in wireless ad hoc networks because they were designed without consideration of ad hoc environments such as node mobility, limited bandwidth, high error probability. To solve this problem, some multicasting protocols for ad hoc network have been proposed in the literature. However, these protocols can not provide high packet delivery ratio, low control packet overhead and low expended bandwidth at the same time. Therefore, in this paper, we propose RTMA that improves multicasting performance in wireless ad hoc networks. RTMA calculates its current region from its position information by using GPS in order to make tree among the multicast group nodes in the same region. The proposed region-based tree method is for high packet delivery ratio, low control packet overhead when many senders send data packets. RTMA makes a reliable tree by using speed information to fill a gap of the weak points of the tree structure. When searching the routing path, RTMA selects the reliable path excluding high speed nodes.

• KIISE Transactions on Computing Practices
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• v.22 no.2
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• pp.101-106
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• 2016

A femtocell network has been attracting attention as a promising solution for providing high data rate transmission over the conventional cellular network in an indoor environment. In this paper, we propose a distributed power control algorithm considering both indoor coverage and data load balancing in the femtocell network. As data traffic varies by time and location according to user distribution, each femto base station suffers from an unbalanced data load, which may degrade network performance. To distribute the data load, the base stations are required to adjust their transmission power dynamically. Since there are a number of base stations in practice, we propose a distributed power control algorithm. In addition, we propose the simple algorithm to detect the faulty base station and to recover coverage. We also explain how to insert a new base station into a deployed network. We present the simulation results to evaluate the proposed algorithms.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.2
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• pp.295-303
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• 2004

In this Paper, we discuss an active TCP link of unsynchronized transmission mode network in two-way traffic and the Improvement of its traffic patron thorough the network pathway of protocol is shown. This is because the traffic pattern is performed on the basis of existing windows which are distributing information in several periods of time in the way of interfacing LTS control module, which is controlling by an information of exceeding the time limit of feedback loop determined by RTP, with TCP. The simulation to utilize this efficiently is performed with the circumstance of bench mark based on physical modeling of the self-similarity traffic in the performance of TCP. In this paper, we use a methodology to understand and evaluate the effect of change of transmitting protocol in sticks under the condition of the self-similar traffic in two-way network and it is shown that an improvement of congestion control by self-similarity under a heavy condition.

• Journal of Internet Computing and Services
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• v.11 no.1
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• pp.1-13
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• 2010

It is not easy to set RED(Random Early Detection) parameter according to environment in managing Network Device. Especially, it is more difficult to set parameter in the case of maintaining the constant service rate according to the change of environment. In this paper, we hypothesize the router that has Multi-core CPU in output queue and propose AI RED(Artificial Intelligence RED), which directly induces Genetic Algorithm of Artificial Intelligence in the output queue that is appropriate to the optimization of parameter according to RED environment, which is automatically adaptive to workload. As a result, AI RED Is simpler and finer than FuRED(Fuzzy-Logic-based RED), and RED parameter that AI RED searches through simulations is more adaptive to environment than standard RED parameter, providing the effective service. Consequently, the automation of management of RED parameter can provide a manager with the enhancement of efficiency in Network management.