• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.5
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• pp.983-987
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• 2004

Pilot symbol assisted modulation (PSAM) can be used for the channel estimation. However, imperfect channel estimates degrade the bit error rate (BER) performance. I derive the exact BER of 16-level quadrature amplitude modulated (16-QAM) orthogonal frequency division multiplexing (OFDM) systems with PSAM in time dispersive Rayleigh fading channels. In real system, there is 2.5 dB penalty in $\overline{\gamma_b}$for the same BER relative to ideal system with perfect channel estimation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.17 no.5
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• pp.433-441
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• 1992

The new synchronous hierarchy with abase signal near 150Mbit/s will become the international standards. An asynchronous video signal will be transmitted in the synchronous network with stuffing synchronization technique. In this study an estimate of power spectrum and effective values of the stuffing jitter signals under the influence of system parameters were obtained. The results show that the real stuffing jitter is greater than the ideal stuffing jitter.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.3
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• pp.370-377
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• 2003

MC-CDMA is a digital modulation technique where a single data symbol is transmitted at multiple subcarriers which are orthogonal to each other. With this technique, frequency diversity can be achieved. The performance of MC-CDMA systems is analyzed, when data is transmitted over multi-path and Doppler fading channel. The performance of this technique, gauged by the average bit error rate, is numerically analyzed for the system with the application of antenna diversity and error control coding.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.2
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• pp.390-396
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• 2009

MC-DS-CDMA is technique where a single data symbol is transmitted at multiple subcarriers which are orthogonal to each other. With this technique, frequency diversity can be achieved. The performance of PSAM MC-DS-CDMA system with the application of STBC antenna diversity is analyzed. The BER performance of this system over multipath fading environment is evaluated, considering the channel estimation ernr, carrier frequency offset, and the nonlinear high power amplifier.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.5
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• pp.980-987
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• 2009

A timing synchronization method is presented for IEEE 802.11a wireless OFDM system. First the signal detection is achieved by measuring the moving energy of the received OFDM signal in two consecutive windows. By measuring the correlation between the short training signal and received envelope signal, fine OFDM symbol synchronization can be acquired. The variance and average value of the correlation value is acquired. And the theoretical values are compared with computer simulation results.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.7A
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• pp.557-567
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• 2005

We evaluate the BER performance of OFDMA system for Wibro services in frequency selective Rayleigh fading channel, considering the carrier frequency offset and the nonlinear high power amplifier. In the uplink OFDMA, nonlinear amplifier and frequency offset introduce larger BER degradation than in the downlink. We explain the reason and obtain the required output back-off of the nonlinear amplifier and value of frequency offset for good BER performance.

• Korean Journal Plant Pathology
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• v.14 no.3
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• pp.223-228
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• 1998

Turnip mosaic virus)TuMV-Ca) was isolated from a Chinese cabbage showing severe mosaic and black necrotic spots symptoms in Korea. The virus was identified as a strain of TuMV by its host range test, particle morphology, serology, double stranded RNA analysis. For detection of the virus, reverse transcription and polymerase chain reaction(RT-PCR) was performed with a set of 18-mer TuMV-specific primers to amplify a 876 bp DNA fragment The virus was rapidly detected from total nucleic acids of virus infected tissues as well as native viral RNA of purified virion particles by RT-PCR. Detection limit of the viral RNA by RT-PCR was 10 fg.

• Proceedings of the Korea Contents Association Conference
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• 2005.11a
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• pp.81-87
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• 2005

Ecotourism is defined as a responsible form of tourism which provide minimum influence on the environment and regional society and maximizes economic benefits and satisfies tourists. So the goal of ecotourism are provide tourism, generate environmental conservation, and residents' economic benefits. The purposes of this study were to emamine visitors' characteristics and ecotourism goals which are providing tourism, environmental conservation, and regional economic benefits through 'Bonghwa Pine Mushroom Festival'.

• Proceedings of the Korea Contents Association Conference
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• 2004.05a
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• pp.94-108
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• 2004

The objective of this research is to define and explain the factors of destination chosen by travel consumers in Agricultural tourism. Their party size we, in general, smaller, and they tend to spend more time planning their trips and to book them further in advance. They also use different information sources when making travel decision. There is also a need to examine in greater depth the proposition that Agricutural Tourism are more compatiable with the principles of ecollogically sustainable tourism than Non Agricultural tourism formats.

• Proceedings of the Korea Contents Association Conference
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• 2005.05a
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• pp.252-260
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• 2005

For an successful performance of conference destination, assessment can be considered into two categories. The first is concerened with the meeting site's environment that covers a city's capability to host international meeting, while the second includes those criteria that deal with the meeting facility offering quality service. The purpose of this article is to contribute to this methodological literature by applying the environment factor and performance technique to the international meeting industry of Seoul.