• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.10
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• pp.1-7
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• 2008

This paper describes the proposal, design, and implementation of a novel WDMX controller which can provide versatile light effects with the increased capability of the mobility and the number of universes for LED lights. Both the algorithm for DMX protocol and how to implement the frame based on a 8bit micro-controller are explained. The conversion algorithm between the DMX frame and wireless LAN 802. 11b protocol stack is introduced and implemented. In final, some experiments are made to verily the interoperability of the developed WDMX controller with a commercial product of LED lights. 최대 9,999 staves with 30 refresh rate per second may have capability to show various light effects.

• Journal of Broadcast Engineering
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• v.8 no.4
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• pp.427-436
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• 2003

Many applications that are transport multimedia data through the networks should put existing network structure to practical use. Because the existing network structure and protocols are designed for static data transmission, multimedia applications with timing concept have limitations for using existence. In this paper, we present limitations of existing network structure for multimedia delivery, survey network element's characteristics in side view of multimedia application, present the streaming protocol for realtime multimedia traffic. Lastly, we consider a protocol stack for MPEG-21 Digital Item transmission using these existing protocols.

• Journal of Internet Computing and Services
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• v.14 no.5
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• pp.27-38
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• 2013

Currently a number of managers exist to manage heterogeneous networks, in this situation, the NETCONF protocol for efficient network management has been proposed as a new protocol. However, the standard NETCONF protocol stack continuous improvement since the establishment but in four layers still have some problems. Especially in situations where there are multiple administrators, problems are more highlighted in operation layer. In this paper, we focus on these issues and the Operation layer has improved the efficiency and flexibility of operations among NETCONF four layers. Additionally, for the inefficiency of updates improved the device settings based on improved operation techniques. In addition, standard protocol NETCONF did not proposed content layer data structure and we propose standard technique of content layer that can generate configuration structure of devices. Improved the three techniques are applied appropriately to the NETCONF, the proposed method and the existing NETCONF was performed experiment to compare with experimental four factors. Compare key factor are four kind as maintaining the probability of network function, the reaction performance about command, the number of control packets, performance of data creation in content layer. Such factors after performing the experiment, the proposed method in this paper is superior to the existing NETCONF and there was confirmed by analysis Experimental results.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.7A
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• pp.688-696
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• 2010

The Proxy Mobile IPv6 (PMIPv6) is a network localized mobility management protocol that is independent of global mobility management protocols. In a single mobility domain (LMD), the mobile node (MN) is not involved in any IP mobility-related signaling and uses only its PMIPv6 home address for all its communication. Subsequently, when the MN moves into another LMD, the MN must change its PMIPv6 home address. In such a circumstance, host-based mobility signaling is activated. Thus, the nature of the network-based mobility of the PMIPv6 cannot be retained. Additionally, if the MN does not support global mobility, it cannot maintain communication with its correspondent node (CN). In this paper, we propose a solution for global mobility support in PMIPv6 networks, called Global-PMIPv6 that allows current communication sessions of a MN without mobility protocol stacks to be maintained, even when the MN moves into another LMD. Thus, Global-PMIPv6 retains the advantages of the PMIPv6 for global mobility support. We then evaluate and compare network performance between our proposed solution and PMIPv6.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.2
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• pp.278-287
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• 2011

NMEA 2000 protocol known as IEC 61162-3 of Multi-talker, Multi-listener and Plug and Play network communication has been adopted as standard network for SOLAS(Safety of Life at Sea) ship by IMO. This paper focuses on the implementation of FPGA and MicroBlaze for NMEA 2000 based gateway, which is able to convert NMEA 2000 protocol into various types of network protocol such as Ethernet, UART and USB using Vertex4-based ML401 board. Each communication module and the stack of NMEA 2000 are mounted on FPGA. To be able to receive each communication data, ML401 board is configured to handle required communication speed. PC based NMEA 2000 monitoring program is developed to verify that data on different networks are correctly converted each other in real time.

• Journal of KIISE:Information Networking
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• v.31 no.3
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• pp.314-326
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• 2004

Bluetooth has been reputed as a wireless ad-hoc networking technology supplying scalable and extensible networks between digital devices. For that kind of networks, scatternet is a most essential part in bluetooth. But past researches on bluetooth scatternet has proposed only possibilities of scatternet algorithm based on simulation results. And many of the researches failed in guaranteeing extensibility and flexibility and had many difficulties in real hardware implementation. In this paper, we proposed node ring scatternet(NRS) algorithm guaranteeing extensible and flexible networks. NRS algorithm is designed for hardware implementation using real commercial bluetooth module. That algorithm is divided into initial formation and reformation. For initial formation, we proposed limited SEEK/SCAN algorithm. For reformation, we proposed DIAC algorithm and Reserved Recovery Node algorithm. And we proposed SFMP(Scatternet Formation ＆ Management Protocol) in protocol stack for real implementation. NRS algorithm is operated in SFMP. Finally, we performed real hardware experiments and evaluated the proposed algorithm. In that experiments, we succeeded in forming scatternet up to 20 nodes. In comparison with other similar algorithm, proposed algorithm have the improvement in scatternet formation delay and success rate.

• Journal of KIISE:Computer Systems and Theory
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• v.36 no.5
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• pp.351-359
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• 2009

Recently with increase of data in the Internet, platform technologies that can process huge data effectively such as Google platform and Hadoop are regarded as worthy of notice. In this kind of platform, there exist network I/O overheads to send task outputs due to the MapReduce operation which is a programming model to support parallel computation in the large cluster system. In this paper, we suggest applying of TIPC (Transparent Inter-Process Communication) protocol for reducing network I/O overheads and increasing network performance in the distributed computing environments. TIPC has a lightweight protocol stack and it spends relatively less CPU time than TCP because of its simple connection establishment and logical addressing. In this paper, we analyze main features of the Hadoop-based distributed computing system, and we build an experimental model which can be used for experiments to compare the performance of various protocols. In the experimental result, TIPC has a higher bandwidth and lower CPU overheads than other protocols.

• Journal of KIISE:Computing Practices and Letters
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• v.9 no.1
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• pp.47-59
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• 2003

The Internet telephony service is one of the commercially successful Internet application services. VoIP technology makes the service come true. VoIP deploys H.323 or SIP as the standard protocol for the distributed multimedia services over the Internet in which QoS is not guaranteed. VoIP carries the packetized voice over the RTP/UDP/IP protocol stack. The data transmission trouble is caused by UDP when the service is provided in private networks and some ISP-provided Internet access networks in the private address space. The Internet telephony users in such networks cannot listen the voices of the other parties in the public Internet or PSTN. Making the problem more difficult, the Internet telephony service considered in this paper gets the incoming voice packets of every session through only one UDP port number. In this paper, three schemes including the terminal proxy, the gateway proxy, and the protocol translation are suggested to solve the problems. The design and implementation of the NAT proxy server based on gateway proxy scheme are described in detail.

• Proceedings of the KIEE Conference
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• 1998.07g
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• pp.2373-2376
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• 1998

This paper describes the development of the SCADA(Supervisory Control and Data Acquisition) system which can be controlled via the Internet. In this paper, the SCADA system is composed of a number of microprocessor-based RTU(Remote Terminal Unit)s, a MMI(Man Machine Interface) host, a SCADA server, and SCADA clients. There are two protocols used in the system. Each RTU and the MMI host are connected by a RS-485 line and CSMA/CD(Carrier Sense Multiple Access / Collision Detection) protocol is used to communicate with each other. TCP/IP(Transmission Control Protocol/Internet Protocol) is used among the MMI host, the SCADA server, and SCADA clients. The equipments installed in the field are controlled by a number of RTUs. The function of the MMI host is to acquire real-time data from RTUs and control them. The SCADA server supports data transfer between the networked MMI host and the SCADA client on the web-server through TCP/lP. Data transfer is possible regardless of the type of network only if there are TCP/lP Winsock-compatible stack driver. The SCADA client is implemented as the shape of web-page by means of JAVA language. Therefore, it runs on a web-browser such as Netscape and Explorer, and allows a number of users to access this SCADA system.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.350-353
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• 2004

The increasing use of Ethernet-TCP/IP network in industry has led to the growing interest in its reliability in real-time applications such as automated manufacturing systems and process control systems. However, stochastic behavior of its medium access scheme makes it inadequate for time-critical applications. In order to guarantee hard real-time communication service in Ethernet-TCP/IP network, we proposed an algorithm running over TCP/IP protocol stack without modification of protocols. In this paper, we consider communication services guaranteeing deadlines of periodic real-time messages over MAC protocols that have unbounded medium access time. We propose a centralized token scheduling scheme for multiple access networks. The token is used to allow a station to transmit its message during the time amount that is appended to the token. The real-time performance of the proposed algorithm has been described.