• Proceedings of the KIEE Conference
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• 1996.11a
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• pp.434-436
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• 1996

This paper deals with the signal communication system for MAGLEV which is indispensible to train control with safety and high speed operation. Therefore it is necessary for signal system to ensure high speed transmission. massive transmission, low error rate, and reliability of information. And the ensured information should be transmitted between ground and on-board for safety and high speed operation. For these reasons, we have considered the guaranteed reliability by applying FSK method and HDLC protocol. Because HDLC has the advantages of high efficiency, high reliability, low bit rate, and bit transparency. HDLC is the appropriate method for data transmission in MAGLEV.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.8A
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• pp.735-744
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• 2006

In this paper, the optimum pump light powers of optical phase conjugator(OPC) are numerically investigated as a function of amplifier spacing in 1,200 km $8{\times}40$ Gbps WDM systems with 0.1, 0.4, 0.8, or 1.6 ps/nm/km dispersion coefficient. It is confirmed that the variation of optimal pump light power dependence on amplifier spacing for NRZ transmission system is smaller than that for RZ transmission system through the evaluations and analysis of eye opening penalty(EOP) characteristics. And, in both cases of NRZ and RZ transmission, the variation of optimal pump light power is more increased as amplifier spacing becomes longer. Additionally, it is confirmed that the best amplifier spacing in NRZ and RZ transmission system is 50 km.

• Journal of information and communication convergence engineering
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• v.8 no.6
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• pp.677-681
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• 2010

This paper proposes a transmission probability control scheme for enhancing the performances of FSA-based RFID system. In order to maximize the system performance, the number of tags attempting to transmit their identifiers in a frame should be kept at a proper level. The reader calculates the transmission probability according to the number of tags within the identification range of reader and then broadcasts it to tags. Tags, in which their slot counter values reach to zero, attempt to transmit their identifiers with the received probability. Simulation results show that the proposed scheme can offer better throughput and delay performance than the conventional one regardless of the number of tags.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.1125-1126
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• 2015

A naval tactical video has utilized to implement network based remote C2 system, but it is difficult to transmit video intelligence data between tactical combat team and base-station due to the distance and sea condition. Threrfore, We first understand the naval tactical video transmission system and identify its limitations. Finally, we present an efficient method to increase transmission rate in the naval tactical video transmission system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.755-757
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• 2009

Since the research of advanced terrestrial digital multimedia broadcasting system is still in progress, and in our previous paper, in which we introduced how to combine one conventional transmitted symbol with two additional bits to form a new symbol transmission, the bit error performance of LP bits is not realizable, because even we implemented the turbo code to protect the LP bits transmission, to obtain a certain good bit error probability, the value of $E_b/N_0$ cost highly. In this paper, we modified the composition of low-priority symbol and high-priority symbol, and through the system presented in previous paper we get a better simulation result of the LP symbol transmission.

• The Transactions of the Korea Information Processing Society
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• v.6 no.11
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• pp.3060-3069
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• 1999

The existed transmissions have PDH and SDH transmission system, which are based on PSTN network. But as the future ATM network is going to be constructed, it is very necessary for ATM network to interwork with PSTN for telephony service. The international standardization organizations like ITU-T, ATM Forum offered CES, VTOA1, VTOA2 and so on for interworking with PSTN service, which spend many network resources and considerable transmission delay. So in this paper, new interworking PSTN for transmission will be proposed to lessen the transmission delay and the network resources.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.676-678
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• 2003

Recently, in according as rapid improvement of telecommunication markets and wireless internet technology, Location- Based Services (LBS) have been discussed as new 'Killer' application. The purpose of LBS is to determine location of user through mobile handset and to offer location information service to end-user. This paper has suggested an efficient transmission scheme of maps data as one of the important content services relating to data transmission of LBS in mobile environment. The basic system consists of three parts : (1) GIS (Geographic Information System) Server for storing, processing and handling map data, (2) Middleware Server for transmitting of map data by request of client, and (3) Client for requesting map data to Server and displaying them on handset. Also, in order to transmit map data, we are to expand WKB (Well Known Binary) in conformance to Simple Feature Specification of OGC (Open GIS Consortium), and increase efficiency of data transmission by developing trans mission data format to be able to transmit lightweight data and considering data compression technology.

• Proceedings of the IEEK Conference
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• 2003.07a
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• pp.53-56
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• 2003

In order to enhance the system capacity of multi rate IEEE 802.11 WLAN, we propose the transmission rate select method using the control frame in this paper. The transmission rate is selected dynamically based on the RSSI(Received Signal Strength Indicator) of received control frame. And we also propose the Enhanced NAV Update method for Fragmented MPDU burst transmission in multirate WLAN environment. This method can improve the system capacity by support the burst transmission of fragmented MPDU.

• Proceedings of the KIEE Conference
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• 2004.10a
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• pp.237-239
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• 2004

Sapporo subway sets up the integrated information system to be aim at the effective and automatic work from the first time. They are expanding integrated system by introducing IT into Serve system positively which developed for recent several years. To keep up with the big size and high speed of information according to integrated system,. the integrated transmission line system which is basic of the integrated system is changed into the system which apply the newest technology. Also, they are aimed at the next generation traffic system through the cooperation of the local administration, for example, test of the multipurpose card using non-contact IC card. This study reviewed the present state of Sapporo subway, the upgrade of information transmission system, and the function of each serve system those are the order of equipment, management of the running, management of the disaster presentation, signal protection, passenger management etc.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.8
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• pp.1780-1786
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• 2005

The phase error generated in the transmission system affects the performance of digital transmission signal. The phase error are generated by random phase noise and tracking phase error due to denier phenomenon. In the mobile satellite communication system that generates the doppler frequency, which is a system with a movement, the proper system phase noise spectrum should be designed based on analyses for phase noise and static phase error effects. Based on the analyses of the doppler frequency and the phase error for bilateral satellite communication system providing an asynchronous service, the phase noise spectrums for the mobile satellite communication are designed in this paper. Also, the available transmission services under the less doppler effect are proposed and the proper signal source units for a required transmission system can be designed under the proposed system phase noise spectrum.