• Proceedings of the IEEK Conference
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• 2009.05a
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• pp.45-47
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• 2009

Wireless Sensor Network(WSN) has been very popular in unattended surveillance systems recently. For Applying WSN into Building Automation system(BAS), a novel hierarchial network structure and static routing algorithm which eliminates the scalability limitation of Zigbee are proposed in this paper. The static routing algorithm relying on the hierarchial network address reduces the computational complexity to a great extent and has a real-time performance which satisfies urgent applications well.

• Proceedings of the IEEK Conference
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• 2002.06e
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• pp.75-78
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• 2002

Since power failures in high-speed communication network, especially in HFC(Hybrid Fiber Coaxial cable) network are critical, microcontroller-based UPS(Uninterrupted Power Supply) are commonly used in the network. Hardware and software of UPS management system is designed and implemented to monitor and control UPS status to supply electric power to ONU and TBA in the HFC network. The result of laboratory tests and field tess of this system shows the scan rate to be 1 to 10 minutes to sufficiently monitor the status of UPS in the network.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2000.05a
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• pp.195-198
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• 2000

We propose a new wavelet neural network structure, for which we apply new recurrent nodes to the network, in this paper for the dynamic system identification and control. We will construct the wavelet neural network by using wavelet frame function. The function does not have the best approximation property, but it may be possible to apply some modification to the structure of the network because the constriction of orthogonality is loosened a little. This wavelet neural network we propose can obtain previous state information by its structure of the network without any addition of input, though the conventional wavelet network needs additional previous state input for the improvement of the dynamic performance. In numerical experience, the performance of the new wavelet neural network we propose in the nonlinear system with uncertainity of parameter Is equal to that of the wavelet network which used the additional previous information input, superior to that of the conventional wavelet network.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1051-1055
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• 2003

Policies are collections of general principles specifying the desired behavior and state of a system. Network management is mainly carried out by following policies about the behavior of the resources in the network. Policy-based (PB) network management supports to manage distributed system in a flexible and dynamic way. This paper focuses on configuration management based on Internet Engineering Task Force (IETF) standards. Network security approaches include the usage of intrusion detection system to detect the intrusion, building firewall to protect the internal systems and network. This paper presents how the policy-based framework is collaborated among the network security systems (intrusion detection system, firewall) and intrusion detection systems are cooperated to detect the intrusions.

• The Journal of Society for e-Business Studies
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• v.6 no.2
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• pp.25-38
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• 2001

ATM is the transport method for the broadband integrated services digital networks(B-ISDN). It may replace existing LAN, MAN and WAN technologies such as CSMA/CD, FDDI, Frame relay, X.25, etc. But it is more complicate than existing network technologies. One of the main difficulties in ATM network is performance management. Specifically, the problems are evaluating the performance and tuning the values of the performance parameters, The goal of this paper is to introduce a system architecture designed for ATM network performance management, The major ingredients of the system are generic performance parameters In be measured from ATM network, performance evaluation models and decision criteria concerning the network performance. In this paper, general requirements for performance management application in ATM network are discussed.

• Journal of Industrial Technology
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• v.27 no.A
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• pp.131-139
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• 2007

The recent advance in wireless network technologies has enabled the streaming media service on the mobile devices such as PDAs and cellular phones. Since the wireless network has low bandwidth channels and mobile devices are actually composed of limited hardware specifications, the transcoding technology is needed to adapt streaming media to given mobile devices. Futhermore owing to the diversity of bandwidth in the wireless network by reason of mobile users' movements and environments, it is difficult to provide stable QoS. In this paper, the autonomic multimedia transcoding system is proposed in order for users to provide network adaptive QoS. Our proposed system is based on the estimation of available bandwidth in wireless network for seamless multimedia streaming service. The proposed system is designed and implemented for various mobile clients. In experiments, we evaluate its seamless multimedia streaming and the adaptation transcoding bit rate according to the changes of bandwidth in wireless network.

• Proceedings of the Korea Society for Simulation Conference
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• 1994.10a
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• pp.12-12
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• 1994

Simulation output knowledge analysis is one of problem-solving and/or knowledge adquistion process by investgating the system behavior under study through simulation . This paper describes an approach to simulation outputknowldege analysis using fuzzy neural network model. A fuzzy neral network model is designed with fuzzy setsand membership functions for variables of simulation model. The relationship between input parameters and output performances of simulation model is captured as system behavior knowlege in a fuzzy neural networkmodel by training examples form simulation exepreiments. Backpropagation learning algorithms is used to encode the knowledge. The knowledge is utilized to solve problem through simulation such as system performance prodiction and goal-directed analysis. For explicit knowledge acquisition, production rules are extracted from the implicit neural network knowledge. These rules may assit in explaining the simulation results and providing knowledge base for an expert system. This approach thus enablesboth symbolic and numeric reasoning to solve problem througth simulation . We applied this approach to the design problem of broadband communication network.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.72-75
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• 2004

In this paper, the task assignment strategy considering communication delay and the priority of distributed tasks is proposed for the real-time network system in order to maximize the utilization of the system. For the task assignment strategy, the relationship among priority of tasks in network nodes, the calculation time of each task, and the end-to-end response time including the network delay is formulated firstly. Then, the task assignment strategy using the genetic algorithm is proposed to optimize the utilization of the system considering the LCM(Least Common Multiple) period. The effectiveness of proposed strategy is proven by the simulation for estimating the performance such as the utilization and the response time of the system in case of changing the number of tasks and the number of network nodes.

• Tribology and Lubricants
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• v.16 no.6
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• pp.461-468
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• 2000

In this study, a neural network based diagnostic system of a rotating spindle system supported by ball bearings was introduced. In order to create actual failure situations, two exemplary abnormal status were made. Out of several possible data source locations, ten measurement spots were chosen. In order to discriminate multiple abnormal status, a neural network system was introduced using back propagation algorithm updating connecting weight between each nodes. In order to find the optimal structure of the neural network system reducing the information sources, magnitude of the weight of the network was referred. Hinton diagram was used to visually inspect the least sensitive weight connecting between input and hidden layers. Number of input node was reduced from 10 to 7 and prediction rate was increased to 100%.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1581-1585
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• 2005

This paper describes the design and implementation of a XCP (Xeline Control Protocol) network system. XCP is an information oriented protocol which delivers information with high reliability according to the predefined rule. The XCP network system is implemented with partly hardware and partly software based on the power line communication(PLC) environment. A network management tool which interacts with devices is also developed. In order to verify the feasibility of the proposed architecture, the implemented XCP network system is evaluated using a lighting control system.