• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.5
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• pp.1608-1615
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• 2010

In this paper, we proposed the method called "DoublePico"(Double Piconet) forovercoming low data transmission rate in a scatternet. This needs a new Ad-hoc network topology to transmit with high rate. Every node performs the function of the relay station. DoublePico has two bluetooth devices that should form two different poconets; every node can make a link between two different piconets. Two different piconets are linked in one node by the link with two bluetooth divices thereby forming the Ad-Hoc network. In this paper, we shows the method of DoublePico which supports about 457kbps of the maximum data transmission rate. This method supports a higher data transmission rate than the traditional bluetooth's Ad-Hoc topology by using analysis and comparison of existing algorithm of bluetooth specification and simulation results. Specifically, this paper focuses on the impact of intererence on the PER (Packet Error Rate), throughput performance, and the throughput improvement with SAW(Stop and Wait)-ARQ scheme in DoublePico.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.2A
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• pp.160-171
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• 2011

The one of the core technologies for ubiquitous computing is WSN. WSN detects the information from the environment around them based on the information perceived from the human and all things and manages the information by connecting to the network in realtime. In this environment, the existing research provides the mechanism that most of sensor nodes in the target area can set the transmission path using RGF. However, unrelated to the target area will be responsible for the energy consumption of nodes that are the problem. In this paper, we propose EEDCP protocol. It is designed to collect data from the specific region on sinks in WSN. EEDCP is the protocol that sets the transmission path for collection data inside the target area in WSN. And this paper is shown that the proposed scheme is more efficient in the energy efficiency and the occurrence rate of isolated nodes by comparison with the previous studies through simulation.

• Journal of the Korea Society of Computer and Information
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• v.16 no.3
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• pp.121-129
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• 2011

One of the major challenges of minimum energy consumption for wireless sensor networks(WSN) environment. LEACH protocol is hierarchical routing protocol that obtains energy efficiency by using clustering. However, LEACH protocol in each round, because the new cluster configuration, cluster configuration, whenever the energy consumed shorten the life of the network. Therefore in this paper, the cluster is formed in WSN environment in early stage and the problems with energy waste have been solved by selecting C-node. In the initial round of proposed model uses 26 percent more than traditional LEACH energy consumption. However, as the round is ongoing, it has been proved by the network simulation tool that the waste of energy could be diminished up to 35%.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.75-81
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• 2005

The GNUnet in P2P system have solved an anonymous(publisher, storer, demander); a service of condition equal for peer. The GNUnet for an anonymous has separated a file and dispersed to the network. But, the 1Kbyte block size of the GNUnet is a creation of many additional block. I and R block has created with indirect point of D block The waste of I and R block appeared to 4% of the original file and the additional network traffic for the block transmission. To resolve the problems, this paper proposes an new scheme of file splitting distribution using P2P networks with the new GNUnet protocol, The GNUnet support minimization of the additional block and for a network traffic. It proposed an efficiency improvement of encording block and routing algorithm.

• The KIPS Transactions:PartC
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• v.10C no.4
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• pp.463-470
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• 2003

Many types of switching fabrics have been proposed for use in ATM networks. Multistage Interconnection Networks (MINs) constitute a large class of ATM switching systems that are widely used in today´s internetworking. One of the most veil-known types of multistage networks is the banyan network. The banyan network is attractive for its simple routing scheme and low hardware complexity, but its throughput is very limited due to internal blocking and output contention. In this paper, we propose an input-buffered dual-banyan switch model with multiple switching fabric between switch input and output to avoid internal and Head-of Line blocking. By performance analysis and simulation, we show that our model has a lower ceil delay and 96% throughput which is much better than other banyan-type switch architecture.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.1
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• pp.97-105
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• 2015

Recently, due to an explosive growth of the internet traffic, the limitations of a current framework for a mobility management have been focused. The current centralized mobility management is prone to several problems and limitations: suboptimal routing, low scalability, signaling overhead, and a single point of failure. To overcome these problems and limitations, IETF is working about the distributed mobility management scheme that the centralized mobility functions of HA(Home Agents) are distributed to networks edges such as access routers. These distributions of mobility functions overcome the limitations of the centralized mobility managements and go with the trend of flat networks e.g. more simple network architecture. This paper analyzes the distributed mobility management based on Proxy Mobile IPv6 and demonstrates the performance superiority.

• Journal of KIISE:Computing Practices and Letters
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• v.15 no.8
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• pp.591-595
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• 2009

Most existing routing protocols for object detection and tracking in wireless sensor networks concentrate on finding ways to detect and track one and more individual objects, e.g. people, animals, and vehicles, but they do not be interested in detecting and tracking of continuous objects, e.g., poison gas and biochemical. Such continuous objects have quite different properties from the individual objects since the continuous objects are continuously distributed across a region and usually occupy a large area, Thus, the continuous objects could be detected by a number of sensor nodes so that sensing data are redundant and highly correlated. Therefore, an efficient data collection and report scheme for collecting and locally aggregating sensing data is needed, In this paper, we propose the Continuous Object Tracking Mechanism based on Dynamic Rectangle Zone for detecting, tracking, and monitoring the continuous objects taking into account their properties.

• The Journal of the Korea Contents Association
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• v.3 no.2
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• pp.65-72
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• 2003

In this paper, the new scheme using a Combined Cache(CC) that combing the Paging and Routing Cache(PRC) and an alternative handoff method according to the type of data transmission for achieving the efficient realtime communication. The PRC and quasi-soft handoff method reduce the path duplication. But they increase the network traffic load because of the handoff state packet of Mobile Host(MH). Moreover the use the same handoff method without differentiating the type of transmission data. Those problems are solved by operating U with a semi-soft handoff method for realtime data transmission and with a hard handoff method for non-realtime data transmission. As a result or simulation a better performance is obtained because of the reduction of the number of control packet in case that the number of cells are below 20. And the packet arrival time and loss of packet decreased significantly for realtime data transmission.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.7
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• pp.40-48
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• 2015

An optical network-on-chip(ONoC) architecture is emerging as a new paradigm for solving on-chip communication bottleneck. Recent studies on ONoC have been focusing on supporting the parallel transmission and avoiding path collisions using wavelength division multiplexing(WDM). However, since the maximum number of wavelengths, which a single waveguide can accommodate is limited by crosstalk and insertion loss. Therefore previous WDM studies based on incrementing the number of different wavelengths according to the number of nodes would be infeasible due to the implementation complexity. To solve such problems, we combined time division multiplexing(TDM) and wavelength-routed ONoC, along with an optimized channel allocation algorithm, which can minimize the number of extra wavelength channels and latency caused by combining TDM scheme.

• KIPS Transactions on Computer and Communication Systems
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• v.8 no.3
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• pp.73-78
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• 2019

Due to frequent topology changes in wireless networks, inter-node link disconnection and path re-establishment occur, causing problems such as overloading control messages in the network. In this paper, to solve the problems such as link disconnection and control message overload, we perform path setup in three steps of the neighbor node discovery process, the route discovery process, and the route management process in the wireless network environment. The link stability value is calculated using the information of the routing table. Then, when the zone master monitors the calculated link value and becomes less than the threshold value, it predicts the link disconnection and performs the path reset to the corresponding transmitting and receiving node. The proposed scheme shows a performance improvement over the existing OLSR protocol in terms of data throughput, average path setup time, and data throughput depending on the speed of the mobile node as the number of mobile nodes changes.