• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.3A
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• pp.406-411
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• 2000

In wireless ATM system, powerful FEC code is required for highly reliable data transmission. In this paper, we propose an adaptive hybrid ARQ scheme using RCPSCCC for WATM system. The code rate of RCPSCC is adjusted to match channel conditions and data types. By using only the effective free distances of outer and inner encoders, we derive upper bounds of the bit and word error probabilities over Rayleigh and Rician fading channels. By applying RCPSCC to the adaptive hybrid ARQ protocol, highly reliable data transmission can be achieved.

• Journal of the Korea Institute of Building Construction
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• v.6 no.3 s.21
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• pp.59-66
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• 2006

This study aims to estimate strength approximate to actual concrete strength by presenting appropriate non-destructive strength estimation expression with admixtures such as fly ash, blast furnace slag and silica fume which are used as cement substitute and owing to theirs of cement owing to their equal conditions to blending characteristics of concrete used for domestic structures and their recyclable properties. As a result of comparing error rate of existing expressions and this estimation expression, error rate of this estimation is reduced compared to existing expressions and has higher reliability. When conventional concrete expression is applied to admixture concrete, error rate occurs and then this study suggests the following estimation expressions depending on types of admixture concrete.

• Journal of the Ergonomics Society of Korea
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• v.19 no.2
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• pp.33-45
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• 2000

Present study was performed to compare different types of teleoperation performance measures. A modified Cooper-Harper rating scale and a distance measure were newly introduced and compared to two traditional measures, the error rate and time-to-completion. Participants performed a simulated telerobotic task with varying visual display interfaces. The results of correlation analyses revealed that the modified Cooper-Harper ratings had a close association with the error rate measure. The distance measure also appeared to be a consistent performance measure, which accounted for both the error rate and time-to-completion. A further analysis, however, showed that the effectiveness of each performance measure varied with the level of task difficulty. The results imply that the choice of performance measure should be made based on the task difficulty as well as the particular task being studied. The results revealed here also have implication for performance measures of various display and control systems including aircraft navigation displays and tactical displays.

• ETRI Journal
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• v.35 no.1
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• pp.166-169
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• 2013

In this letter, we propose a data randomization scheme for endurance and interference mitigation of deeply-scaled multilevel flash memory. We address the relationships between data patterns and the raw bit error rate. An on-chip pseudorandom generator composed of an address-based seed location decoder is developed and evaluated with respect to uniformity. Experiments performed with 2x-nm and 4x-nm NAND flash memory devices illustrate the effectiveness of our scheme. The results show that the error rate is reduced up to 86% compared to that of a conventional cycling scheme. Accordingly, the endurance phenomenon can be mitigated through analysis of interference that causes tech shrinkage.

• Proceedings of the IEEK Conference
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• 2004.06a
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• pp.11-14
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• 2004

Digital Video Broadcasting - Satellite (DVB-S) [1] (EN 300 421(bibliography)) was introduced as a standard in 1994. However, by combing with higher order modulation, promise more powerful alternatives to the DVB-S / DVB-DSNG coding and modulation schemes. Variable rate coding and modulation (VCM) may employed to provide different levels of error protection to different service components. Adaptive coding and modulation (ACM) provides more exact channel protection and dynamic link adaptation to propagation conditions, targeting each individual receiving terminal. By these reasons, DVB-S2 introduced. This paper derives exact symbol error rate(SER) of 16-Amplitude Phase Shift Keying(APSK) modulation by using Craig's formula. 16-APSK modulation is used in DVB-S2. The difference between Union Bound and Craig's formula is 1.26dB in low SNR and 0.1dB in high SNR.

• Proceedings of the KIEE Conference
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• 1987.07b
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• pp.869-873
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• 1987

In this study, we have examined the multi-level QPRS system in point of error rate, which requires narrow bandwidth and has Little ISI. The generalized error rate equations of multi-level QPRS signal have been derived in the presence of Gaussian noise and co-channel CW interference. And the error rate performance of 9, 49, 225 QPRS system is investigated as parameters of carrier power-to-noise power, carrier power-to -interference power. Also, we have investigated the effect of carrier offset.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.7
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• pp.15-22
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• 1996

In the soliton transmission system for a long-length and high bit rate data transmission systme using the nonlinear/dispersive optical fibers, the improtant problem is the loss characteristics and is the limited transmission rate by interaction forces. In this paper, It is explained the reasons of moved time position for the soliton peak value due to interaction force sof adjacent solitons. And for the analysis of interaction force affection level in the losslessmedia, we define the percent parameter of error rate due to the interaction forces and propose the optimum time distance of adjacent solitons by peak value tracking methods. With the results, initial percent of error is approximately 50% when itme difference between adjacent solitons is 5 times of funddametnal soliton pulse width. And it is confirmed that maximum transmission length of th esolitons is approximately 38 times of fundamental soliton period, which the maximum allowable percoent of error is 50%.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39A no.2
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• pp.86-91
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• 2014

Holographic data storage (HDS) has a number of advantages, including a high transmission rate through the use of a charge coupled device array for reading two-dimensional (2D) pixel image data, and a high density capacity. HDS also has disadvantages, including 2d intersymbol interference by neighboring pixels and interpage interference by multiple pages stored in the same holographic volume. These problems can be eliminated by modulation codes. We propose a 7/9 error-correcting modulation code that exploits a Viterbi-trellis algorithm and has a code rate larger (about 0.778) than that of the conventional 6/8 balanced modulation code. We show improved performance of the bit error rate with the proposed scheme compared to that of the simple 7/9 code without the trellis scheme and the 6/8 balanced modulation code.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.2
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• pp.32-39
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• 1996

Hybrid decision decoding for the extended hamming codes without retransmission, which is a combination of hard and soft decision decoding, is proposed and its performance is analyzed in this paper. As results, hybsrid decision decoding shows a little bit higher residual bit error rate than soft decision decoding. However, as the size of the extended hamming code increases, the difference of th enumber of comparisons increases further. In addition, hybrid decision decoding shows almost same residual bit error rate as hard decision decoding with retrassmission and shows much lower residual bit error rate than hard decision decoding without retransmission.

• MALSORI
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• no.53
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• pp.103-118
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• 2005

The performance of speech recognition system is degraded by mismatch between training and test environments. Recently, Stereo-based Piecewise LInear Compensation for Environments (SPLICE) was introduced to overcome environmental mismatch using stereo data. In this paper, we propose several methods to improve the conventional SPLICE and evaluate them in the Aurora2 task. We generalize SPLICE to compensate for covariance matrix as well as mean vector in the feature space, and thereby yielding the error rate reduction of 48.93%. We also employ the weighted sum of correction vectors using posterior probabilities of all Gaussians, and the error rate reduction of 48.62% is achieved. With the combination of the above two methods, the error rate is reduced by 49.61% from the Aurora2 baseline system.