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

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.40 no.9
• /
• pp.1808-1818
• /
• 2015

Recently, the wind power has experienced great attentions and growths among many renewable energy sources. To increase the power generation performance and economic feasibility, the size of wind turbine (WT) is getting bigger and most of wind power plants are being constructed on offshore. Therefore, the maintenance cost is relatively high because boats or helicopters are needed operators to reach the WT. In order to combat this kind of problem, remote monitoring and control system for the WT is needed. In this paper, the small-scale WT monitoring and control system is implemented using wireless sensor network technologies. To do this, sensor devices are installed to measure and send the WT status and control device is installed to receive control message for specific operation. The WT is managed by control center through graphic user interface (GUI) based monitoring and control software. Also, smart device based web-program is implemented to make the remote monitoring of the WT possible even though operators are not in control room.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.19 no.2
• /
• pp.185-190
• /
• 2009

In this paper, an observer-based intelligent controller for the nonlinear networked control systems with packet loss is proposed for wireless sensor network. For the intelligent control of the nonlinear system, it uses the fuzzy system with Takagi-Sugeno (T-S) fuzzy model. The observer is designed for the fuzzy networked control system, and the output feedback controller is proposed for the stability of estimates and errors. The stability condition of the closed-loop system with the proposed controller is represented to the linear matrix inequality (LMI) form, and the observer and control gain are obtained by LMI. An example is given to show the verification discussed throughout the paper.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.40 no.7
• /
• pp.1354-1362
• /
• 2015

Heterogeneous network technology is expected to be a core technology for 5G mobile communications. 5G mobile network would be composed of many base stations even have mobility, then the operator should connect base stations through the wireless backhaul technology. This paper presents Ultra Wide Area Wireless Backhaul Network System with massive array antenna. We conducted link budget analysis for Ultra Wide Area Wireless Backhaul Network and performance analysis of massive array antenna system through the transmission simulator based on beamforming technology. In wide area ($10km^2$) wireless backhaul system composed of massive antenna, we achieved 5 bps/Hz average spectral efficiency with 1 W transmission power per beam.

• Proceedings of the Korean Institute of Intelligent Systems Conference
• /
• 2005.11a
• /
• pp.87-90
• /
• 2005

The Intelligent Home provides convenient and comfortable living environment by performing automatic control, heating and air-conditioning, ventilation, home appliances control, home robot control, energy management, visitor management security management, internet, heath state monitoring, etc. through wired/ wireless network and device in the household. Along with the presentation of the features of economical broadband power line communication in the network configuration for new and old houses, its improvement method is proposed.

• Journal of KIISE:Computing Practices and Letters
• /
• v.16 no.7
• /
• pp.804-808
• /
• 2010

In this paper, we propose Restricted Angle-control Flooding considered density network of sensor nodes and node‘s limit energy. Restricted Angle-control Flooding, increase energy efficiency by reducing unnecessary candidate nodes involved in forwarding closer to the destination. And The Hole when faced with our proposal to raise rates data through Hole Detection which is sender‘s forwarding area is extended or broadcast to the entire network. Compared to the traditional flooding, we show the superiority at the node’s energy consumption, data rate and network lifetime through the performance.

• Journal of Institute of Control, Robotics and Systems
• /
• v.13 no.12
• /
• pp.1198-1206
• /
• 2007

It is common to use PC or Digital picture frame in stand-alone fashion to view images, movies, or to listen MP3 musics which are considered as multimedia contents, However, such existing methods have weakness for expanding network requirements or augmenting extra data, in such case inevitably requiring external devices. With keeping in mind for such expansion, in this study, we have suggested a new concepts of network module which may utilize an image server for data transmission, in the proposed module, data alarm packet was defined for alerting incoming data from the image server and it became possible to synchronize between the image server and device not only in wired but also in wireless environments through UART. The method consists of a control module for an image server and a synchronization module between the server and the device. We have also tested the feasibility for future commercial usages such as advertisements through performance evaluations.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.10 no.2
• /
• pp.289-296
• /
• 2015

Wireless multimedia sensor network senses and transfers mass multimedia data. Also, it is sensitive to latency. This thesis proposes a routing technique based on traffic priority in order to improve the network efficiency by minimizing latency. In addition, it proposes a congestion control mechanism that uses packet service time, packet inter-arrival time, buffer usage, etc. In this thesis, we verified the reduction of packet latency in accordance with the quality level of packet as a result of the performance analysis through the simulation method. Also, we verified that the proposed mechanism maintained a reliable network state by preventing packet loss due to network overload.

• 제어로봇시스템학회:학술대회논문집
• /
• 2003.10a
• /
• pp.1300-1304
• /
• 2003

The following paper deals with a control problem of a mobile robot in home network environment. The home network causes the mobile robot to communicate with sensors to get the sensor measurements and to be adapted to the environment changes. To get the improved performance of control of a mobile robot in spite of the change in home network environment, we use the fuzzy inference system with multiple reward reinforcement learning. The multiple reward reinforcement learning enables the mobile robot to consider the multiple control objectives and adapt itself to the change in home network environment. Multiple reward fuzzy Q-learning method is proposed for the multiple reward reinforcement learning. Multiple Q-values are considered and max-min optimization is applied to get the improved fuzzy rule. To show the effectiveness of the proposed method, some simulation results are given, which are performed in home network environment, i.e., LAN, wireless LAN, etc.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.15 no.10
• /
• pp.6310-6316
• /
• 2014

The increase in the Internet and smart device users requires high-level network security. Network security consists of Web Firewall, Network Firewall, IPS, DDoS system, UTM (Unified Treat Management), VPN, NAC (Network Access Control), Wireless security, Mobile security, and Virtualization. Most network security solutions running on IPv4, and IPv6 network services are not sufficiently ready. Therefore, in this paper, this study designed and implemented important functions of Network Access Control (NAC), which include IPv6 host detection, isolation, blocking and domain assignment for the IPv6 network. In particular, domain assignment function makes 128 bits IPv6 address management easy. This system was implemented on a KISA IPv6 test-bed using well known devices. Finally, the test result showed that all IPv6 based wired and wireless devices were well-controlled (detection, blocking, isolation and domain assignment).