• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.2
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• pp.205-212
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• 2011

The high performance intelligent robots have become to use a lot of sensors, actuators and controllers which are connected via bus-type networks while the point to point connection was widely used in-robot networks of existing robots. The bus topology makes the robot system share data internally and it can also reduce the weight of the robot because of smaller wiring harness. The CAN is one of serial bus communication protocols typically used for in-vehicle networks and now it can also be used for in-robot networks because of its low cost and reliability. A performance evaluation system for this type of networked system is developed to analyze the real-time operation and the reliability of a serial-bus network, and the usefulness of the developed evaluation system is shown by some experiments for a network of many CAN nodes.

• Proceedings of the KIEE Conference
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• 1999.07g
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• pp.3249-3252
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• 1999

In this paper, we present the Tele-PACS of radiology, which uses the communication network as asymetric satellite data communication system. The asymetric satellite data communication system uses receive-only satellite links for data delivery and PSTN(Public Switched Telephone Network) modem or N-ISDN(Integrate Services Digital Network) for communication. The satellite communication linking shows the very high-speed performance than terrestial linking such as 28.8 kbps modem linking and 56Kbps linking. The satellite linking is 5 - 10 times faster than the 56Kbps linking. We conclude that 1) Satellite networking is currently the cheapest and fastest solution for internet access. 2) Web-based Image-Viewer enables small size hospitals in rural area to connect to central PACS easily and to retrieve the image data reliably. 3) The suggested teleradiology system using satellite networking could be adequate to fast telemedicine and telecare for rural hospitals especially located in geographically isolated areas such as islands.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.22 no.5
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• pp.1057-1068
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• 2012

According to advance on vehicle technology, many kinds of ECU(Electronic Control Unit) are equipped inside the vehicle. In-vehicle communication among ECUs is performed through CAN(Controller Area Networks). CAN have high reliability. However, it has many vulnerabilities because there is not any security mechanism for CAN. Recently, many papers proposed attacks of in-vehicle communication by using these vulnerabilities. In this paper, we propose an wireless attack model using a mobile radio communication network. We propose a secure authentication mechanism for in-vehicle network communication that assure confidentiality and integrity of data packets and also protect in-vehicle communication from the replay attack.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.5
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• pp.688-695
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• 2013

Networked Control Systems(NCS) contain the structure which controllers, actuators and sensors are connected to communication network. And they have been adopted in large and complicated plant area due to the advantages of mitigating computational bottleneck and maintenance. Although this structure provides many benefits, it brings in problems of unpredictable communication delay, data loss and corruption. This phenomena have to be considered in designing NCSs since it affects on overall control system stability. This paper introduces network traffic test method for ethernet based NCSs to find out maximum network usage which guarantee stable control operation. Test results shows this methods can be adopted in various types of NCSs and contributes economical system design and effective system operation.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.137-138
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• 2006

NEMO(Network MObility) is a complex model of mobile network which refers to a forming of Nested Mobile Network by a moving transportation like vessel, bus, or a train which then moves a Mobile Node, or by a movement of a PAN(Personal Area Network). In a Nested NEMO, pinball routing is the primary obstacle as exemplified by the IPv6 environment. This paper will focus on improving such models as RRH, RBU+ and MANET Approach, that attempted to solve pinball routing by route optimization.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.2
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• pp.114-119
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• 2010

Network technology has been developed rapidly for digital service in these days. ZigBee, one of the IEEE 802.15.4 protocols, supporting local communication has become the core technology in the wireless network area. In this paper we designed an integrated fire monitoring system using a mobile robot and the ZigBee sensor nodes which are deployed to monitor fires. When a fire breaks out, the image information of the scene of a fire is transmitted by an autonomous mobile robot and we also monitor the current position of the robot. Furthermore, the data around the place where the fire breaks out and the positions of the sensor nodes can be transmitted to a server via the multi-hop communication in the real time.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.1
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• pp.191-210
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• 2011

Topology management, which includes neighbor discovery, tracking and updating, is a key area that need to be dealt with appropriately to increase network performance. The use of directional antenna in Wireless Mesh Networks is beneficial in constructing backbone networks viewing the properties of directional antenna. The backbone links must be robust to obtain better network performance. In this paper, a simple yet effective topology protocol is presented that performs well compared to its predecessors. Our protocol constructs the topology with the constraints in the number of links per node. The full topology is constructed in two phases. The resultant topology is termed as Web-topology. The topology formed is robust, efficient, and scalable.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.6
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• pp.2583-2605
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• 2016

Fingerprint positioning is a main stream and key technique for seamless positioning systems. In this paper, we develop a performance evaluation testbed for fingerprint based Wireless Local Area Network (WLAN) positioning system. The testbed consists of positioning server, positioning terminal, Access Point (AP) units, positioning accuracy analysis system and testing scenarios. Different from other testbeds tended to focus on testing in same situation, in the proposed testbed, a couple of scenarios are set to test the positioning system including indoor and outdoor environments. Handset-side positioning mode and network-side positioning mode are provided simultaneously. Variety of motion models, such as static model, low-speed model and high-speed model are considered as well as different positioning algorithms. Finally, some implementation cases are analyzed to verify the credibility of the testbed.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.68.4-68
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• 2001

In the area of factory automation (FA), a lot of researches are being executed about intelligent system using network. Conventional industry controllers are implemented the connection with other controllers by using asynchronous serial communications. These methods of communication have an advantage of easy implementation but have disadvantages of lack of real-time characteristics needed in motion control, slow baud rate too low to exchange required data sufficiently and low integrity because of different communication protocol. Serial real-time communication system (SERCOS) provides international standard communication specifications (IEC 61491) for interfacing between control units and drives from different manufacturers, has real-time ...

• Journal of information and communication convergence engineering
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• v.11 no.4
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• pp.293-297
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• 2013

Delivery of high quality video over a wide area network with large number of users poses great challenges for the video communication system. To ensure video quality, multiple descriptions have recently attracted various attention as a way of encoding and visual information delivery over wireless network. We propose a new efficient multiple description coding (MDC) technique. Quincunx lattice sub-sampling is used for generating multiple descriptions of an image. In this paper, we propose the application of a directional discrete cosine transform (DCT) to a sub-sampled quincunx lattice to create an MDC representation. On the decoder side, the image is decoded from the received side information. If all the descriptions arrive successfully, the image is reconstructed by combining the descriptions. However, if only one side description is received, decoding is executed using an interpolation process. The experimental results show that such the directional DCT can achieve a better coding gain as well as energy packing efficiency than the conventional DCT with re-alignment.