• Proceedings of the KIEE Conference
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• 2006.07d
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• pp.2009-2010
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• 2006

This paper presents an adaptive line coupler to match input impedance of the Power line Communication(PLC) modem between access impedance of the power line. This line coupler provides maximum signal power transmiting capability, high reliability. The structure of this coupler is simple and designed to make a easy and low cost. The proposed line coupler is suitable for Amplitude Shift Keying(ASK) or Phase Shift Keying(PSK) modem. To figure out our models, the analysis of the transmitting features of power line channel is performed in the time domain at the carrier frequency. As a result of this study, we present the values of capacitors in the capacitor bank and adaptive line coupler circuit.

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.1446-1448
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• 2004

Communication line used in the rail-road have different use from subscriber line in the public telecommunication. But, when an existing communication equipment is replaced, by applying new high-speed transfer technology, we can anticipate the increase of transmission rate and decrease of waiting time according to high-speed of communication line. cost reduction of infrastructure construction and maintenance/repair according to centralization of communication line and transmission equipment. In this study, the transmission scheme of several xDSL(Digital Subscriber Line) modems were compared and analyzed. The way of applying xDSL modem to the metal cable which is used in the JR(Japan Railroad) is analyzed. In addition, the result tested in railroad communication line was reviewed.

• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.557-560
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• 1998

In this paper, we presetn the WWW (world-wide-web) base dtelePACS, which uses the communication network as asymmetric satellite data communication system (ASDCS). Web-based telePACS is imple-mented with JAVA language. Through the internet, web-based TelePACS can make it possible for remote hospital or doctor to access PACS data and information easily and cheaply. The ASDCS uses receive-only satellite links for data delivery and PSTN (Public switched telephone Network) modem or N-ISDN (narrow band integrate services digital network) for communication. The satellite communication linking shows the very high-seed performance such as 10-30 times faster than the modem linking.To solve the speed limits of internet, JPEG and wavelet compression methods were adapted in WWW-based TelePACS and were evaluated by PSNR (peak signal-to-noise ratio) and by radiological experts that 10:1 or less JPEG and wavelet compression may be acceptable for diagnostic purposes. Consequently, we get the conslusion that our system is suitable for tele-radiology and telemedicine world widely.

• Information and Communications Magazine
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• v.19 no.9
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• pp.77-85
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• 2002

In this paper, we introduce an ADSRC(hdvanced DSRC) OFDM packet communication system which has been developed by ETRI. The ADSRC system is targeted to provide high terminal mobility, high data rate and seamless service in roadside environment for mobile office services. We discuss the requirements of the ADSRC communication system for mobile office services, and the system design specification to meet them with regard to air interface. The ADSRC packet communication systems consist of the MAC processor block, the OFDM packet modem block and the RF block. The MAC processor block handles medium access control and the test. The OFDM packet modem transmits data packets at up to 24Mbps adaptively and recovers the data from RF block. We describe the ADSRC packet communication system architecture and the ADSRC system protocol.

• Journal of the Korea Institute of Military Science and Technology
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• v.18 no.6
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• pp.755-761
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• 2015

Satellite Air-defence Warning System receives the aircraft/ballistic track information and air defense control command obtained from Master Control & Reporting Center (MCRC) and Air Missile Defence Cell (AMD Cell) Systems. It consists of terminal and control system to propagate track information and air defense control command control via the military satellite communications. In this paper, there were described track information, air defense control command, the frame structure of modem to transmit a voice information and modulation/demodulator design, network synchronization methods via the satellite network.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.162-164
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• 2010

Terrestrial trunked radio (TETRA) standard specifies shortened Reed-Muller (RM) codes as forward error correction means for control signals. In this paper, we compare decoding algorithms for RM codes in TETRA, in terms of performance and complexity trade-off. Belief propagation and majority logic decoding algorithms are selected for comparison.

• Proceedings of the KIEE Conference
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• 2001.11c
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• pp.280-283
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• 2001

Recently Many technologies of the Powerline communication are proposed these technologies used high carrier frequency for high speed and stability, but high carrier frequency is restricted by the low of electric wave. So we will propose electric monitoring system that used the commercial powerline communication modem, isn't restricted by the low. Our objects are, first, we compared the low in korea, EU(CENELEC), and USA(FCC). second, proposed a spec of the powerline communication modem. third, design that the electric monitoring system using commercial A/D converter control and manage the electric equipment.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.119.4-119
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• 2001

It is the advantage of PLC that digitalization and networking of existing facility can be organized at low price because there is no need further construction of communication line considering that home appliance, information device and various kind of control devices are digitalized at low price. Moreover, AMR(Automatic Meter Reading) is very attractive to utility company because not only does it reduce the cost of reading meter, but also it can control and monitor the demand for energy. So, it can solve the consumers problem best and easily. It also can be easily realized that the utilities can expand there areas to values-added service through existing network. The performance of the PLC modem which is being developed now is not moven enough and much more test for outdoor modem is needed especially. Therefore, we, KEPRI, concentrate our efforts on configuring AMR system for test and investigation of the actual performance of various kinds ...

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.11a
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• pp.53-54
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• 2005

This paper describes that send some signal from encoder attached to crankshaft of marine-engine to measuring instrument using power line modem(PLM) and display cylinder pressure, rpm and etc. on LCD. Conventional method that sends signal along the long signal line has some inconvenience from too long signal line length caused by huge volume of ship's engine. Power line modem can have short signal line from outlets to measuring instrument. Because it use exist power line for send signals, so it have low installation cost and could have good merits in job sites. Through this experiment, pressure in cylinder, engine rpm and etc. signals through PLM are well recognized at measuring instrument.

• The Journal of Korean Medicine
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• v.27 no.3 s.67
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• pp.132-144
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• 2006

Objectives: In order to improve our understanding of the meridian, it is necessary to analyze how meridian theory formed. In this regard, the primitive form of meridians requires further study. Methods: Data from the pre-Han and Han dynasties were used, as such data document primitive forms of the meridian. Results: 1. Some of the terminology of the primitive meridians did not include symmetrical terms such as hand, foot, yin and yang; instead, terms of travel area were used. 2. In the primitive meridians, most travel from the bottom to the top. 3. The twelve meridian system had not yet been introduced into the primitive system. 4. In the primitive meridians, only a few had branches. 5. In the primitive meridians, they did not have obvious connections with the five vital organs and the six viscera. Conclusions: Although the primitive meridian system differs from the modem, studying the primitive meridians may improve our understanding of the modem meridians.