• Journal of Korea Multimedia Society
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• v.10 no.10
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• pp.1295-1309
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• 2007

A wireless access point is used for all communications in the infrastructure mode wireless home networking, including communication between mobile nodes in the same service area. When a mobile station in the infrastructure mode wireless home networking moves into a dead zone, the communication between the mobile station and the access point is disconnected. To solve this problem, the existing wireless home network platforms focus on the ad hoc mode wireless home networking. However, the performance of an ad hoc network is poorly decreased when the number of mobile participating in the ad hoc network increases. In addition, although the ad hoc routing technique is necessary to support seamless communication of mobile nodes, the existing routing protocols, such as AODV and DSR, do not consider that a wireless channel state could affect performance significantly. Therefore, we propose a wireless home networking platform based on the ESCOD (End-to-end Seamless multi-hop COnnection based on Dual network mode) technique incorporating the VLR (Virtual Link Routing) scheme that supports end-to-end seamless connections. Extensive experiments show that the proposed wireless home networking platform incorporating the VLR scheme outperforms wireless home networking platforms based on the AODV and the DSR routing protocols respectively in terms of low packet transmission failure rate, fast packet transmission time, high TCP performance, and a wider coverage area of wireless home networks.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.16 no.12
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• pp.1348-1356
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• 1991

The need for MAN(Metropolitan Area Network)has been increased by demands for high performance comuter communication. According to the definition of MAN by IEEE 802.6 MANs have diameter of about 50km, bandwidth of more than 1Mbps, and limited delay, Because optical fibers have unique characteristics that make them attractive for the implementation of MANs several fiber optic networks suitable for MAN application have been proposed. Those networks have drawbacks such as unlimited delay, many processing nodes and limited number of stations. Also IEEE 802.6 proposals and oters improved networks were proposed, but they have complicated access procedures and data buffering and difficulties in implementation. This paper descrives the design of Fiber Optic Metropolitan Area Network in Seoul(Seoul FOMAN) to overcome the drawback, Seoul FOMAN is hierarchical MAN and designed based on the topology of 43 end offices in Seoul. We propose MAN topology, proper access protocol and analyze the performance.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.464-467
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• 2000

In this paper we introduce the network based multi-motors control system using CAN(Controller Area Network) The traditional multi-motors control system has many problems in the view of reliability and economy because of the amount and complexity of wiring noise and maintenance problems etc, These problems are serious especially when the motor controllers are separated widely CAN is generally applied in car networking in order to reduce the complexity of the related wiring harnesses. These traditional CAN application techniques are modified to achieve the real time communication for the multi-motor control system. And also the position synchronization technique is developed and the proposed methods are verified experimentally.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.4
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• pp.632-638
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• 2012

ZigBee network, based on PHY, MAC layer provides a specification for a suite of high level communication protocols using small, low-power digital radio based on an IEEE 802.15.4 standard. Meshing is a type of daisy chaining from one device to another. This technique allows the short range of an individual node to be expanded and multiplied, covering a much larger area. Each wireless technology that makes it to market serves a special purpose or function. Zigbee provides short-range connectivity in what is called a personal-area network (PAN). Within ZigBee PAN coordinator as manages an entire ZigBee network, the short range of frequency band was only selected because the technology allows typically less than 100 kbp or ZigBee troubles in retransmission processing and delaying data tranmission works to create unproductive condition of work. This research was proposed the method, based on short range frequency of zigBee nodes enable to long range of remote data transmission with specific algorithm tools.

• Journal of Institute of Control, Robotics and Systems
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• v.11 no.8
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• pp.709-716
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• 2005

As a way to build more efficient and intelligent container cranes for todays hub ports, communication networks are used to interconnect numerous sensors, actuators, controllers, and operator switches and consoles that are spatially distributed over a crane. Various signals such as sensor values and operator's commands are digitized and broadcast on the network instead of using separate wiring cables. This not only makes the design and manufacturing of a crane more efficient, but also easier implementation of intelligent control algorithms. This paper presents the performance evaluation of CAN(Controller Area Network), TTP(Time Triggered Protocol) and Byteflight that can be used for cranes. Through discrete event simulation, several important quantitative performance factors such as the probability of a transmission failure, average system delay (data latency) and maximum system delay have been evaluated.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.1 no.2
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• pp.137-143
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• 1997

From now on, the network is being developed into PSTN(public switched telephone network) and PDN(public data network), that is depend on the form of data. The former one pursues sending voice, and the latter one pursues sending data. But it causes big loss of the economy and efficiency. So, ISDN, processing voice and data at same time, gives a big profit to user. To enlarge the ISDN at the narrow area, it is necessary that study to send the mixture form of voice and data in LAN environment. So, this paper proposes the algorithm about the mixture form of voice and data in ethernet and token-ring. that is widely used in these days.

• ETRI Journal
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• v.37 no.2
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• pp.262-272
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• 2015

In particular, for a practical mobile robot team to perform such a task as that of carrying out a search and rescue mission in a disaster area, the network connectivity and localization have to be guaranteed even in an environment where the network infrastructure is destroyed or a Global Positioning System is unavailable. This paper proposes the new collective intelligence network management architecture of multiple mobile robots supporting seamless network connectivity and cooperative localization. The proposed architecture includes a resource manager that makes the robots move around and not disconnect from the network link by considering the strength of the network signal and link quality. The location manager in the architecture supports localizing robots seamlessly by finding the relative locations of the robots as they move from a global outdoor environment to a local indoor position. The proposed schemes assuring network connectivity and localization were validated through numerical simulations and applied to a search and rescue robot team.

• International Journal of Contents
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• v.5 no.1
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• pp.21-26
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• 2009

Peer to Peer (P2P) utilizes the resources of an offered service without the need for a central server or preexistent server-client, making it a desirable network environment for data exchange based on direct connection between peers. Proposed by Sun Microsystems. JXTA(Juxtapose) is a typical P2P system and distributed computing model that does not require central service resources and is flexible to deal with various network configuration changes. Meanwhile. Mobile Ad-hoc NETwork(MANET) is a typical wireless network configured with mobile nodes and without an infrastructure. where a network is established by direct connection or through other peers in the propagation area. Thus, MANET maintains the latest path information by establishing paths and changing path information for communication between peers in a highly mobile wireless network. Accordingly. this article proposes the JXTAMANET method for wireless networks to enable JXTA to be applied to MANET. NS2 is used to evaluate the performance and the proposed architecture is shown to produce better results than a conventional flooding method.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2014.06a
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• pp.144-145
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• 2014

IoT (Internet of Things) is connected to all things Internet-based people and things, things and objects that communicate information between said intelligent technologies and services. Shipping each of a variety of devices that act independently from each other, but, it is actively interlock with each other is not easy practically days. Ship it within the means of communication, the communication between the ship, the communication between ship and shore configuration, SAN (Ship Area Network), RFID/USN, broadband communications, satellite communications and IT technology to a variety of marine environments for the safe navigation the ship's safety management system for the configuration you want to discuss the plan.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.5
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• pp.47-57
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• 2006

This paper presents a network-based traction control system(TCS), where several electric control units (ECUs) are connected by a controller area network(CAN) communication system. The control system consists of four ECUs: the electricthrottle controller, the transmission controller, the engine controller and the traction controller. In order to validate the traction control algorithm of the network-based TCS and evaluate its performance, a Hardware-In-the-Loop Simulation(HILS) environment was developed. Herein we propose a new concept of the HILS environment called the network-based HILS(Net-HILS) for the development and validation of network-based control systems which include smart sensors or actuators. In this study, we report that we have designed a network-based TCS, validated its algorithm and evaluated its performance using Net-HILS.