• Progress in Superconductivity
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• v.7 no.1
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• pp.36-40
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• 2005

The problem of fluctuation-induced digital errors in a rapid single flux quantum (RSFQ) circuit has been a very important issue. In this work, we calculated the bit error rate of an RSFQ switch used in superconductive arithmetic logic unit (ALU). RSFQ switch should have a very low error rate in the optimal bias. Theoretical estimates of the RSFQ error rate are on the order of $10^{-50}$ per bit operation. In this experiment, we prepared two identical circuits placed in parallel. Each circuit was composed of 10 Josephson transmission lines (JTLs) connected in series with an RSFQ switch placed in the middle of the 10 JTLs. We used a splitter to feed the same input signal to both circuits. The outputs of the two circuits were compared with an RSFQ exclusive OR (XOR) to measure the bit error rate of the RSFQ switch. By using a computerized bit-error-rate test setup, we measured the bit error rate of $2.18{\times}10^{-12}$ when the bias to the RSFQ switch was 0.398 mA that was quite off from the optimum bias of 0.6 mA.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.05a
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• pp.210-216
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• 2000

The features of bit error rate (BER) are discussed, how to analyze statistics of the bit error rate. How many will the BER be improved after correcting one single-error in the block\ulcorner The answer is satisfactory in this paper.

• Journal of the Korean Magnetics Society
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• v.8 no.6
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• pp.395-399
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• 1998

평면 실리콘 헤드를 사용한 디스크 드라이브(hard disk:HDD) 시스템의 average bit error rate(ABER)를 계산하였다. ABER을 구하기 위해 3차원 유한 요소법을 사용하여 헤드 자장 분포를 구하고 error rate response surface(ERRS)를 구하엿다. 다음에 track misregistration(TMR)과 계산되어진 ERRS를 컨볼루션하여 ABER을 시뮬레이션 하였다. 허용할 수 잇는 에러 율이 10-6이라 하고 트랙 피치가 3.7$\mu$m일 때, 요구되는 TMR은 0.36$\mu$m이었다. 이는 트랙 피치의 9.7이었다.

• Progress in Superconductivity and Cryogenics
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• v.7 no.1
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• pp.21-24
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• 2005

The problem of fluctuation-induced digital errors in a rapid single flux quantum (RSFQ) circuit has been very important issue. So in this experiment, we calculated error rate of RSFQ switch in superconductiyity ALU, The RSFQ switch should have a very low error rate in the optimal bias. We prepared two circuits Placed in parallel. One was a 10 Josephson transmission lines (JTLs) connected in series, and the other was the same circuit but with an RSFQ switch placed in the middle of the 10 JTLs. We used a splitter to feed the same input signal to the both circuits. The outputs of the two circuits were compared with an RSFQ XOR to measure the error rate of the RSFQ switch. By using a computerized bit error rate test setup, we measured the bit error rate of 2.18$\times$$10^{12}$ when the bias to the RSFQ switch was 0.398mh that was quite off from the optimum bias of 0.6mA.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.4
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• pp.97-105
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• 1994

Transform image coding using DCT is proved to be efficient in the absence of channel error but its performance degrades rapidly over noisy channel. In this paper, in the case of appling bit selcetive error correction coding that protects some significant bits in a codeword, an efficient allocation method of imformation bits and additive redundancy bits used for quantization and error correction coding respectively under constant transmission bit rate is proposed, and its performance is analyzed. As a result, without increasing trasmission bit rate, PSNR can be improved up to 7~8 [dB] below bit error rate $10^2$ and the image without blocking effect caused by bit error resulted from channel noise can be recostructed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.4B
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• pp.208-216
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• 2007

Wireless Sensor Networks (WSNs) are characterized by low capacity on each nodes and links. Wireless links have high bit error rate (BER) parameter that changes frequently due to the changes on network topology, interference, etc. To guarantee reliability in an error-prone environment, a retransmission mechanism can be used. In this mechanism, the number of retransmissions is used as a parameter that controls reliability requirement level. In this paper, we propose an Error Adaptive Transport Protocol (EATP) for WSNs that updates the number of retransmissions regularly to guarantee reliability during bit error rate changes as well as to utilize energy effectively. The said algorithm uses local information, thus, it does not create overhead problem.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1355-1359
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• 2004

The two way subscriber transmission systems have tendency to spread its carrier frequency bandwidth or information bit rate and average bit error rate according to popularization of high speed information through the digital communication system, transmission medium and the Internet. This fact is an important incentive to realize new systems. These two way subscriber transmission systems usually use same cable or same carrier frequency bandwidth for up stream channel and down stream channel. In the systems, the disturbances of noise, crosstalk or fading affect the characteristics. Specifically, these disturbances cause the decrease of information bit rate and degradation of transmission quality. This paper proposes the improved method of their degradations using the particular feature of two way subscriber transmission systems and it makes clear proposed method is effective by theoretically and some numerical examples.

• Proceedings of the Korean Magnestics Society Conference
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• 1997.11a
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• pp.96-97
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• 1997

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.38 no.2
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• pp.87-94
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• 2001

A soft error rate for DRAM was predicted in connection with the leakage current in cell capacitor. The charge in cell capacitor was decreased during the DRAM operation, and soft error retes due to the leakage current were calculated in various operation mode of DRAM. It was found that the soft error rate of the /bit mode was dominant with small leakage current, but as increasing the leakage current memory mode shown the dominant effect on soft error rate. Using the 256M grade DRAM structure it was predicted that the soft error rate was influenced by the change of the cell capacitance, bit line capacitance, and the input voltage sensitivity of sense amplifier, and these results can be used to the design of the optimum cells in the next generation DRAM development.

• Journal of the Optical Society of Korea
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• v.14 no.1
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• pp.22-27
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• 2010

Bit error rate (BER) monitoring is the ultimate goal of performance monitoring in all digital transmission systems as well as optical fiber transmission systems. To achieve this goal, optimization of the decision threshold must also be considered because BER is dependent on the level of decision threshold. In this paper, we analyze a pseudo-error counting scheme and propose an algorithm to achieve both BER monitoring and adaptive decision threshold optimization in optical fiber transmission systems. To verify the effectiveness of the proposed algorithm, we conduct computer simulations in both Gaussian and non-Gaussian distribution cases. According to the simulation results, BER and the optimum decision threshold can be estimated with the errors of < 20% and < 10 mV, respectively, within 0.1-s processing time in > 40-Gb/s transmission systems.