• Archives of Plastic Surgery
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• v.47 no.2
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• pp.178-181
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• 2020

In this report, we present a case in which good results were achieved by treatment using a free jejunal patch graft with virtual endoscopy (VE) assistance in a patient whose swallowing had failed to improve for 40 years after he mistakenly swallowed sulfuric acid, despite pectoralis major myocutaneous flap grafting and frequent balloon dilatation surgery. During the last 20 years, virtual computed tomography imaging has improved remarkably and continues to be used to address new challenges. For reconstructive surgeons, the greatest advantage of VE is that it is a noninvasive modality capable of visualizing areas inaccessible to a flexible endoscope. Using VE findings, we were able to visualize the 3-dimensional shape beyond the stenosis. VE can also help predict the area of the defect after contracture release.

• Journal of the Korea Society of Computer and Information
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• v.11 no.5 s.43
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• pp.195-201
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• 2006

In multicarrier code division multiple access(MC-CDMA), the total system bandwidth is divided into a number of sub-bands, where each subband may use direct-sequence(DS) spreading and each subband signal is transmitted using a subcarrier frequency. In this paper, the system performance analysis of MC-CDMA using to gain combining(EGC) and maximal ratio combining(MRC) method over frequency selective Nakagami-m fading channel is analyzed. In the proposed system, a data sequence is serial-to-parallel converted, and MC-CDMA is used on each of the parallel data streams. The data streams are spread at both the symbol fraction level and at the chip level by the transmitter. In this paper, the compare to analysis,two standard diversity combining techniques, EGC and MRC, The good performance of system using to MRC more than EGC

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.4
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• pp.539-549
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• 1999

In this paper, the bit error rare (BER) performance of DS/CDMA DQPSK communication system in the presence of multi access interference, impulsive noise and Nakagami fading is investigated. The DS/CDMA DQPSK communication system adopts Maximum Ratio Combining (MRC) diversity reception and error correcting BCH code technique to enhance system performance. Using the derived error probability equation, the error rate performance of DS/CDMA DQPSK communication system has been evaluated and shown in figures to discuss as a function of impulsive index(A), Gaussian noise to impulsive noise power ratio($\Gamma$'), multi access interference(Κ), Nakagami fading parameter(m), the number of diversity branch (Ｌ), the number of error correction symbol (t), PN code sequence length(N) and $E_b/N_0$. The error performance of DS/CDMA-MDPSK signals improve by adopting MRC diversity and BCH(15,7) coding technique in the environment of impulsive noise plus Nagakami fading. From the results, we known that proposed system is affected by multi access interference, impulsive noise and Nakagami fading in radio communication system environment. Also, BER performance of DS/CDMA DQPSK communication system cam be improved increasing either the power of desired signal or the value of Gaussian noise to impulsive noise power ratio. And BCH(15,7) code technique is more effective to restrain the affection of multi access, interference, impulsive noise and Nakagami fading in DS/CDMA DQPSK communication system than MRC diversity reception technique.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1995.10a
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• pp.7-10
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• 1995

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1995.10a
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• pp.3-6
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• 1995

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1996.10a
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• pp.104-107
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• 1996

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1995.06a
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• pp.18-21
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• 1995

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1995.06a
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• pp.151-154
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• 1995

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.7
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• pp.1202-1207
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• 2006

In this paper we analyze the performance improvement of the M-ary FSK systems for low power and low data rate applications. This contribution presents a unified analysis of its MRC diversity, uncoded and performance in A WGN, m=2, m=3, Rayleigh and one sided Gaussian fading channels using optimum noncoherent demodulation with Reed-Solomon(RS) codes. The results of this paper should be useful as benchmarks of obtainable performance and as a reference for validating the results of simulation studies when slow fading models are applicable.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.1
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• pp.52-60
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• 2001

In this paper proposes a multi-carrier MFSK-DPSK/DS-CDMA combined modulation techniques in Nakagami fading environment. Also, multi-carrier DS-CDMA combined system is a promising technique for mobile communications systems, since it has a strong immunity to multipath fading and increasing bandwidth efficiency. The modulations under consideration are noncoherent M-ary frequency shift keying (MFSK)and an MFSK based joint frequency phase modulation utilizing differential phase shift keying (DPSK). With the result, performance improvement of power efficiency and bandwidth efficiency combined system in multi-carrier MFSK-DPSK/DS-CDMA are better then conventional communication system.