• Journal of the Institute of Electronics Engineers of Korea SC
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• v.42 no.2 s.302
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• pp.39-48
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• 2005

This paper proposes a novel approach to recognize nine kinds of motion for a multifunction myoelectric hand, acquiring four channel EMG signals from electrodes placed on the forearm. To analyze EMG with properties of nonstationary signal, time-frequency features are extracted by wavelet packet transform. For dimensionality reduction and nonlinear mapping of the features, we also propose a feature projection composed of PCA and SOFM. The dimensionality reduction by PCA simplifies the structure of the classifier, and reduces processing time for the pattern recognition. The nonlinear mapping by SOFM transforms the PCA-reduced features to a new feature space with high class separability. Finally a multilayer neural network is employed as the pattern classifier. From experimental results, we show that the proposed method enhances the recognition accuracy, and makes it possible to implement a real-time pattern recognition.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.9 s.339
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• pp.29-40
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• 2005

In this paper, we propose a Cluster-based Multicast Routing (CMR) suitable for mobile ad-hoc networks. The main features that our proposed method introduces are the following: a) mobility-based clustering and group based hierarchical structure in order to effectively support stability and scalability, b) group based mesh structure and forwarding tree concepts in order to support the robustness of the mesh topologies which provides limited redundancy and the efficiency of tree forwarding simultaneously, and c) combination of proactive and reactive concepts which provide low route acquisition delay and low overhead. The performance evaluation of the proposed protocol is achieved via modeling and simulation. The corresponding results demonstrate the Proposed multicast protocol's efficiency in terms of packet delivery ratio, scalability, control overhead, end-to-end delay, as a function of mobility, multicast group size, and number of senders.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.9 no.5
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• pp.589-602
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• 1998

While ATM technology results in considerable advantages(less overhead, increased throughput) in an optical networks, It causes severe problems(single and burst error) when ATM is transmitted over an error-prone channel, such as wireless link. In this paper we describe our investigation on ATM over wireless network. we first evaluate performance of ATM data transmission over a wireless link. Secondly we analyze performance improvements of Forward Error Correction(FEC) or ARQ(Automatic Repeat reQuest) scheme applied to wireless ATM link and provide performance comparison between FEC and ARQ through the use of packet error rate and throughput. Lastly we suggest error control architecture to overcome the impact of the bit error characteristics of a wireless link on wireless ATM network.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.25 no.3
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• pp.703-713
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• 2015

The linking system between the control system and the field devices in the existing EMS/SCADA, in order to increase the reliability of the data, and access control through the separation of external network. Currently, There is a tendency that the need for connection to an external network that takes into account the economic aspect, systematic management and efficiency of operations is increasing. Such is evolved linkage section, is to have more security vulnerabilities than in the past, Eventually communication EMS/SCADA linkage section requires special management method. In this paper, taking into account the domestic environment, were presented the security Certification and Accreditation technology that was applied to serial DNP3 and TCP/IP based DNP3 that are mainly used in EMS/SCADA linkage section. Presented to security of Certification and Accreditation technology, divided into Resource Robustness Test and Malicious Packet Test for evaluate the safety. Each of the security requirements and evaluation method in proposed technology, is an attempt to present the differentiation of the existing Certification and Accreditation technology.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.12
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• pp.2975-2981
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• 2014

Micro-magnetic detection system is used to detect small particles in an automatic transmission valve body, which signal noise and time-delay may occurs in process of signal transmitting and filtering. In this paper, we present the design and implement of a micro-magnetic detection system based on wireless sensor networks in conveyer belt. Micro-magnetic detection system consists of five modules which are magnetic sensor detector, signal processing unit, wireless sensor networks, system control unit and system monitoring unit. Our experimental results show that the proposed wireless micro-magnetic detection system improves both accuracy and time delay compared to the wired system; therefore, it may apply for wireless micro-magnetic detection system by analysis of packet reception rate.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.12
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• pp.2839-2846
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• 2014

New VHF band for use in VDE is determined by WRC-12 due to the overload of AIS VDL, and the system characteristics of the VDE is recommended as ITU-R M. 1842-1. CS-TDMA, a multiple access method of AIS class B, is recommended as that of the VDE. It is inefficient for CS-TDMA just applying the report interval used in AIS class B to transmit high speed data with higher payload in the aspect of efficiency. In this paper, a simulation is executed in order to determine adequate report interval according to the number of active ships that affects directly network traffic. To this end, the performance of CS-TDMA, which includes the number of received packets, reception success rate, channel utilization, and collision rate, is investigated via a simulation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.794-797
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• 2015

As the interest in VANET is increased, a study on the beacon message transmission between vehicles is actively being made. IEEE 802.11p/1609.4 standard is based on a multichannel system consisting of multiple service channels (SCH) and a control channel (CCH). Multiple SCHs are defined for nonsafety data transfer, while the CCH is used to broadcast safety messages called beacons and control messages (i.e., service advertisement messages). However, most messages broadcast in the only one CCH belong to safety application that must be contested in dense vehicular network. This paper suggests safety message transfer algorithm in dense vehicular congestion. The proposed algorithm is that the priority of safety messages is decided by decision tree and messages are stored in proper queues according to their priorities. Then, safety messages with higher priorities are sent in turn by CCH in the assigned time. The proposed algorithm decreases the beacon transmission delay and increase on the probability of a successful beacon reception in an IEEE 802.11p/1609.4-based network.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.4C
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• pp.338-346
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• 2012

Wireless sensor network (WSN) technology provides a variety of medical and healthcare solutions to assist detection and communication of body conditions. However, data reliability inside WSN might be influenced to healthcare routing protocol due to limited hardware resources of computer, storage, and communication bandwidth. For this reason, we have conducted various wireless communication experiments between nodes using parameters such as RF strength, battery status, and deployment status to get a optimal performance of mobile healthcare routing protocol. This experiment may also extend the life time of the nodes. Performance analysis is done to obtain some important parameters in terms of distance and reception rate between the nodes. Our experiment results show optimal distance between nodes according to battery status and RF strength, or deployment status and RF strength. The packet reception rate according to deployment status and RF strength of nodes was also checked. Based on this performance evaluation, the optimized sensor node battery and deployment in the developed our mobile healthcare routing protocol were proposed.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.46 no.5
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• pp.37-43
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• 2009

Streaming video service over wireless and mobile communication networks has received significant interests from both academia and industry recently. Specifically, mobile WiMAX (IEEE 802.16e) is capable of providing high data rate and flexible Quality of Service (QoS) mechanisms, supporting mobile streaming very attractive. However, we need to note that streaming videos can be partially deteriorated in their macroblocks and/or slices owing to errors on OFDMA subcarriers, as we consider that compressed video sequence is generally sensitive to the error-prone channel status of the wireless and mobile network. In this paper, we introduce an OFDMA subcarrier-adaptive mobile streaming server based on cross-layer design. This streaming server system is substantially efficient to reduce the deterioration of streaming video transferred on the subcarriers of low power strength without any modifications of the existing schedulers, packet ordering/reassembly, and subcarrier allocation strategies in the base station.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.48 no.4
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• pp.40-46
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• 2011

Wireless Sensor Networks(WSNs) have shown a lot of good outcomes in providing a various functions depending on industrial expectations by deploying ad-hoc networking with helps of light loaded and battery powered sensor nodes. In particular, it is strongly requested to develop an algorithm of cross-layer control between 2-layer and 3-layer to deriver the sensing data from the end node to the sink node on time. In this paper, based on the above observation we have proposed an IEEE802.15.4 based self priority routing scheme under UC Berkely TinyOS platform. The proposed beacon based priority routing (BPR) algorithm scheme utilizes beacon periods in sending message with embedding the high priority data and thus provides high quality of service(QoS) in the given criteria. The performance measures are the packet Throughput, delivery, latency, total energy consumption. Simulation results under TinyOS Simulator(TOSSIM) have shown the proposed scheme outcome the conventional Ad hoc On-Demand Distance Vector(AODV) Routing.