• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.3B
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• pp.493-502
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• 2010

In this paper we propose a scalable sensor network system that makes mesh network among the sink nodes to solve the scalability problem of existing sensor network which is caused by multi-hop networking between the sensor nodes. In the proposed system, the sink nodes have the wireless networking ability to communicate with another sink nodes in mesh fashion, and with the monitoring nodes which is located in the local area or internet area. Especially, the system includes L4(Application Layer) routing mechanism that provides subscribe/publish service to serve selective transmission of sensor data to the specific monitoring nodes. The collected sensor data is transmitted to the monitoring nodes when the sensor data is matched with the monitoring node's interesting value.

• Journal of Digital Convergence
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• v.13 no.7
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• pp.207-212
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• 2015

The sensor network that is component of the Internet of Things require a lot of research to select the best route to send information to the anchor node, to collect a number of environment and cost efficient for communication between the sensor life. On the sensor network in one of the components of IOT's environment, sensor nodes are an extension device with low power low capacity. For routing method for data transmission between the sensor nodes, the connection between the anchor and the node must be accurate with in adjacent areas relatively. Localization CA (Centroid Algorithm) is often used although an error frequently occurs. In this paper, we propose a range-free localization method between sensor nodes based on the Radical Line in order to solve this problem.

• Journal of the Society of Naval Architects of Korea
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• v.57 no.4
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• pp.221-229
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• 2020

Naval ships could be seriously damaged by enemy attacks in battle. Moreover, this damage could be spread and deteriorated into a secondary accident. Secondary accidents that have adverse effects on naval ship's survivability, such as fire, flood, smoke extension, and patient occurrence, are defined as casualties. These casualties sharply degrade the survivability of naval ships. Furthermore, naval ships could be burned-out and sunk by casualties in isolated sea. Therefore, damage control and rapid suppression of the casualties in the naval ships is essential. This study was conducted in the establishment of suppression paths according to the characteristics of each casualty so that the developed system can support the rapid suppression in an emergency and even the training situation on a regular state. To establish the suppression paths, the two-dimensional numerical map is designed by converting the three-dimensional features of the naval ships, and the well known algorithms are compared to present the appropriate one for path finding problem on the naval ships. Finally, we devised a specific routing algorithm that fits the characteristics of each casualty in accordance with the Korean Navy's doctrines and handbooks of casualty suppression.

• Journal of the Korea Society of Computer and Information
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• v.11 no.1 s.39
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• pp.157-165
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• 2006

This paper proposes a new output-buffered multicast ATM switch with tandem crosspoints switching fabric, named the MTCOS(Multicast Tandem Crosspoint Output-buffered Switch). The MTCOS consists of multiple simple crosspoint switch fabrics, named TCSF(Tandem Crosspoint Switch Fabric) , and concentrated output buffers for efficient multicasting. The TCSF resolves the cell delay deviation problem which the self-routing crossbar switches inherently have. Further, it offers multiple concurrent pathes from one input to multiple output ports. It also provides multi-channel switching by easy software configuration and has several desirable characteristics such as scalability, high Performance, and modularity. A shared traffic concentration and output queuing strategies of the MTCOS results in lower cell loss as well as lower cell delay time over a wide range of multicast traffic. Furthermore, it has lower hardware complexity than that of the SCOQ and Knockout multicast switch to achieve the same Knockout concentration rate as the conventional switches. It is shown that the proposed switch can be easily applied to design high performance for any multicast traffic by analytic analysis and computer simulation.

• Journal of Korea Society of Industrial Information Systems
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• v.11 no.3
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• pp.47-58
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• 2006

Address Auto-configuration capability is one of important advantages of IPv6 protocol This function enables the IPv6 hosts to configure IPv6 networks automatically, while IPv6 routers still have to be configured manually. To solve this problem, we propose RACP(Router Auto-Configuration Protocol), a new address auto-configuration protocol which configures all routers of a small network consisting of several routers and sub-networks automatically. The RACP protocol can automatically create and deliver IPv6 prefixes and routing informations of all routers on the network by using the network's prefix assigned by ISP. The proposed RACP can be used to set up network automatically for a small IPv6 site such as a small office network, a home network without the assistance of network administrator.

• 전자공학회논문지 IE
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• v.44 no.1
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• pp.20-26
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• 2007

Most researches on the mobile ad hoc network (MANET) have been focused on routing protocols, but for the real service provision DNS(Domain Name System) has to be supported first. Due to the inherent characteristics of the mobile ad hoc network, the DNS of the wired network is assumed to be not good for the MANET environment. The approach of distributed DNSs can easily adapt to the node mobility, but incurs the name conflict resolution overhead. On the other hand, the centralized approach performs the name resolution based on the unicast communication without causing the name conflict resolution overhead. The most important issue of the centralized approach is to provide the seamless name resolution service under server mobility. Therefore, in this paper, we propose a new centralized DNS, Manet DNS, which works efficiently on name allocation and management and solves the network merging and partitioning problem as well as providing the seamless name resolution service.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.12A
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• pp.994-1005
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• 2011

In this paper, we propose a novel approach to optimize the movement of mobile sink node, called AMSP(Adaptive Mobile Sink Path) for mobile sensor network environments. Currently available studies usually suffer from unnecessary data transmission resulting from random way point approach. To address the problem, we propose a method which uses the Hilbert curve to create a path. The proposed method guarantees shorten transmission distance between the sink node and each sensor node by assigning orders of the curve according to sensor node density. Furthermore, The schedule of the sink node is informed to all of the sensing nodes so that the Duty Cycle helps the network be more energy efficient. In our experiments, the proposed method outperforms the existing works such as TTDD and CBPER by up to 80% in energy consumption.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.103-109
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• 2005

Research about P2P system have recently a lot of attention in connection of form that pass early Centralized P2P and is Decentralized P2P. Specially, Structured P2P System of DHT base have a attention to scalability and systematic search and high search efficiency by routing. But, Structured P2P System of DHT base have problem, file can be located only their unique File IDs that although user may wish to search for files using a set descriptive keyword or do not have the exact File ID of the files. This paper propose extended-CAN mechanism that creates File ID of Contents base and use KID and CKD for commonness keyword processing to support keyword search in P2P System of DHT base.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.11
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• pp.1071-1075
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• 2010

Because a sensor node in wireless sensor networks(WSNs) has limited resources, such as battery capacity and memory, data aggregation techniques have been studied to manage the limited resources efficiently. Because sensor network uses wireless communication, a data can be disclosed by attacker. Thus, the study on data protection schemes for data aggregation is essential in WSNs. But the existing data aggregation methods require both a large number of computation and communication, in case of network construction and data aggregation processing. To solve the problem, we propose a data protection scheme based on Hilbert-curve for data aggregation. Our scheme can minimizes communications among neighboring sensor nodes by using tree-based routing. Moreover, it can protect the data from attacker by doing encryption through a Hilbert-curve technique based on a private seed, Finally, we show that our scheme outperforms the existing methods in terms of message transmission and average sensor node lifetime.

• Journal of KIISE:Information Networking
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• v.36 no.4
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• pp.309-321
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• 2009

Nowadays, requests of connecting to the Internet while moving are increasing more and more, and various technologies have been developed for satisfying those requests. The IETF nemo WG standardized "Network Mobility Basic Support Protocol" for supporting mobile network through extending existing MIPv6 protocol for supporting host mobility. But, mobile networks can be nested while they are changing their location. And if they are multi -level nested, that causes some problems because of protocol characteristic. In this paper, we try to solve the problem that is complicated routing path caused by multi-level nesting of mobile networks with our limited prefix delegation method. We give a little modification to the standard protocol and add some functions to mobile router. With results from analysis, we could say that our method has better performance than other proposed methods.