• Journal of KIISE:Computing Practices and Letters
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• v.16 no.12
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• pp.1224-1228
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• 2010

The existing cluster-based routing protocols have some problems. Firstly, because of selecting cluster head at random, they occur a node concentration problem. Secondly, they have a low reliability for data communication due to the less consideration of node communication range. Finally, data communication overhead is greatly increased because of sending all sensor node information to sink node for constructing clusters. To solve these problems, we in this paper, propose a cluster-based routing protocol using message reception success rate. Firstly, to solve the node concentration problem, we design a cluster head selection algorithm based on node connectivity and devise cluster spliting/merging algorithms. Secondly, to guarantee data communication reliability, we use message reception success rate. Finally, to reduce data communication overhead, we use only neighbor nodes information at both cluster construction and cluster head selection.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.11B
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• pp.956-966
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• 2004

Nowadays, NGN(Next Generation Network) is evolving into network with packet based QoS.\ulcorner This paper presents the recovery method as a selecting way of more efficient path in MPLS network that reduces the service interruption time. In order to increase the efficiency of usage of recovering resource which is one of major functions of disorder recovering, it opens the state information of each Node both to fault detector and bandwidth broker so that it reduces message transmission time for recovery when functional disorder occurs. in addition, by effective management and adjustment of required bandwidth of entire network depending on the changes of traffic load, it improves the efficiency of bandwidth usage. and in MPLS network supporting priority selection function, it allocates domains depending on the traffic relating to priority order to the entire network so that\ulcorner it efficiently allocates proper resources to the restoring process between the entry and the end for the traffic of high priority and for low priority traffic, it restores path oかy inside disordered domain. by doing this, it reduces resetting time and unnecessary massage transmission.

• Journal of KIISE:Information Networking
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• v.31 no.2
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• pp.196-206
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• 2004

In the Next Generation Internet(NGI) backbone network, a Dense Wavelength Division Multiplexing (DWDM) technology has been more and more highlighted to cover the increasing subscribers and bandwidth requirement. For such a DWDM network, Routine and Wavelength Assignment (RWA) is the essential problem to establish the optimal path and assign a wavelength efficiently to the selected path in resource utilization. However, the existing RWA algorithms do not consider the congestion in the network so that the performance of then is so limited. To solve this problem, in this paper, we introduce a new RWA algorithm, called Multi Wavelength-Minimum Interference path Routing (MW-MIPR) that establishes a routing path to minimize the interference for many potential future connection setup request. And then, we also propose a wavelength-routed QoS routing scheme based on differentiated QoS classes with applying MW-MIPR algorithm. Simulation results are also given to prove the efficiency of the proposed algorithms.

• Spatial Information Research
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• v.17 no.3
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• pp.251-259
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• 2009

As a result of the current trend towards promoting conservation of the ecosystem, there have been various studies conducted to determine ways to establish an ecological network. The development of analytical methods and an environmental database of GIS has made the creation of this network more efficient. This study focuses on the development of an urban spatial decision support system based on 'Landscape Ecology Theory'. The spatial decision support system suggested in this study consists of four stages. First, landscape patch for the core areas, which are major structures of the ecological network, was determined using the GIS overlay method. Second, a forest habitat was investigated to determine connectivity assessment. Using the gravity model, connectivity assessment at the habitat forest was conducted to select the needed connecting area. Third, the most suitable corridor routes for the eco-network were presented using the least-cost path analysis. Finally, a brief investigation was conducted to determine the conflict areas between the study result and landuse. The results of this study can be applied to urban green network planning. Moreover, the method developed in this study can be utilized to control urban sprawl, promote biodiversity.

• The KIPS Transactions:PartA
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• v.11A no.4
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• pp.277-284
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• 2004

This paper presents a facial expression control method of 3D avatar that enables the user to select a sequence of facial frames from the facial expression space, whose level of details the user can select hierarchically. Our system creates the facial expression spare from about 2,400 captured facial frames. But because there are too many facial expressions to select from, the user faces difficulty in navigating the space. So, we visualize the space hierarchically. To partition the space into a hierarchy of subspaces, we use fuzzy clustering. In the beginning, the system creates about 11 clusters from the space of 2,400 facial expressions. The cluster centers are displayed on 2D screen and are used as candidate key frames for key frame animation. When the user zooms in (zoom is discrete), it means that the user wants to see mort details. So, the system creates more clusters for the new level of zoom-in. Every time the level of zoom-in increases, the system doubles the number of clusters. The user selects new key frames along the navigation path of the previous level. At the maximum zoom-in, the user completes facial expression control specification. At the maximum, the user can go back to previous level by zooming out, and update the navigation path. We let users use the system to control facial expression of 3D avatar, and evaluate the system based on the results.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.11 no.6
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• pp.757-763
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• 2018

It is very difficult to achieve sufficient data rate and required quality of service due to the time-varying nature of the radio channel and various jammers such as path loss, delay, Doppler, shadowing and interference. Especially, the propagation path between the transmitting antenna and the tracking antenna mounted on the fuselage during the test and evaluation of the projectile system considered in this paper is based on the rapid movement of the projectile, the interference due to multipath fading due to the terrain, The propagation path may be blocked. In order to effectively improve the multipath fading occurring in the wireless communication system, a diversity combiner technique is required. In this paper, to derive the design and improvement schemes for the space diversity combiner technique among the diversity combiner schemes, the BER performance of maximum ratio combining (MRC) and selection combining (SC) In an adaptive SC / MRC diversity combiner that operates with MRC when it is lower than the specified threshold criterion when comparing the SNR between two signals received from the channel and operates with SC at high and combines the two received signals The BER performance of the system was compared and analyzed.

• Journal of Digital Convergence
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• v.18 no.12
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• pp.47-57
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• 2020

This paper aims to show the development pattern of the impact of artificial intelligence on the arts and culture according to the scenario analysis, and suggests the direction of the arts and culture content industry in the future. We assume four scenarios based on creativity of artificial intelligence beyond humans and controllability for them, then explore the path leading to each scenario. In addition, for the most ideal route to coexist with artificial intelligence, we propose the provision of safety system for human and artificial intelligence, innovation of the education system, and preemptive investment from now on.

• Journal of KIISE:Information Networking
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• v.31 no.2
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• pp.233-241
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• 2004

In this paper, we propose a packet-lossless fast rerouting scheme at a link/node fault in MPLS (Multiprotocol Label Switching) network with minimized accumulated buffer delay problem at ingress node. The proposed scheme uses a predefined, alternative LSP (Label Switched Path) In order to restore user traffic. We propose two restoration approaches. In the first approach, an alternative LSP is initially allocated with more bandwidth than the protected working LSP during the failure recovery phase. After the failure recovery, the excessively allocated bandwidth of the alternative LSP is readjusted to the bandwidth of the working LSP. In the second approach, we reduce the length of protected working LSP by using segment-based restoration. The proposed approaches have merits of (ⅰ) no buffer delay problem after failure recovery at ingress node, and (ⅱ) the smaller required buffer size at the ingress node than the previous approach.

• Journal of Korea Multimedia Society
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• v.12 no.11
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• pp.1593-1608
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• 2009

If a certain relay node in multi-hop wireless networks might become a malicious node that does not cooperate with other nodes or a selfish node, network throughput will be dramatically decreased. Most of existing ad hoc routing protocols assuming that the nodes will fully cooperate with other nodes do not resolve the problem of network performance degradation due to malicious and selfish nodes. This paper presents the CARE (Cooperative Ad hoc routing protocol based REputation) scheme incorporating the reputation management that can achieve a multi-hop wireless network with high throughput performance. The proposed scheme provides the horizontal cross-layer approach which can identify misbehaving malicious, selfish nodes dropped out of the hop-by-hop based packet processing in the network and then set up an optimal packet routing path that will detour misbehaving nodes. And the vertical cross-layer approach contained in the CARE scheme attempts to improve the quality of routing paths by exploiting the quality of link information received from the MAC layer. Besides, it provides high TCP throughput by exploiting the reputation values of nodes acquired from the network layer into the transport layer. A case study on experiments and simulations shows that the CARE scheme incorporating vertical and horizontal cross-layer approaches yields better performance in terms of the low rate of packet loss, fast average packet delivery time, and high TCP throughput between end-to-end nodes.

• Convergence Security Journal
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• v.12 no.1
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• pp.3-8
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• 2012

MANET composed wireless nodes without fixed infrastructure provides high flexibility, but it has weak disadvantage to various attack. It has big weakness to DDoS attack because every node perform packet forwarding especially. In this paper, packet transmission information control technique is proposed to reduce damage of DDoS attack in MANET and search location of attacker when DDoS attacks occur. Hierarchical structure using gateway node is adopted for protect a target of attack in this study. Gateway node in cluster is included like destination nodes surely when source nodes route path to destination nodes and it protects destination nodes. We confirmed efficiency by comparing proposed method in this study with CUSUM and measured the quantity consumed memory of cluster head to evaluate efficiency of information control using to location tracing.