• 한국정보통신설비학회:학술대회논문집
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• 2005.08a
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• pp.154-158
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• 2005

In this paper, we design optical receiver composed of CDR(clock and data recovery), SA(sense amp), TIA(transimpe dence amplifier), and decision circuit. The optical receiver can be classified to two main block, one is Deserializer composed of CDR and SA, another is PD receiver composed of preamplifier(샴), peak detector, etc. In this paper, we propose CDR using delayed data topology that could improve defects of existing CDR. The optical receiver that is proposed in this paper has the role of translation a 1.25 Gb/s optical signal to $10{\times}125 Mb/s$ array electric signals. This optical receiver is verified by simulator(hspice) using 0.35 um CMOS technology.

• Journal of IKEEE
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• v.17 no.4
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• pp.544-549
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• 2013

This paper describes a modified binary phase detector (Bang-Bang phase detector - BBPD) for jitter reduction in clock and data recovery (CDR) circuits. The proposed PD reduces ripples in the VCO control voltage resulting in reduced jitter for CDR circuits. A 2.5 Gbps CDR circuit with a proposed BBPD has been designed and verified using Dongbu $0.13{\mu}m$ CMOS technology. Simulation shows the CDR with proposed PD recovers data with peak-to-peak jitter of 10.96ps, rms jitter of 0.86ps, and consumes 16.9mW.

• Textile Coloration and Finishing
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• v.9 no.4
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• pp.39-46
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• 1997

In this study, Two types of polyester fabrics were hydrolysed with NaOH using the CDR m/c of pad-steam type and the Sofleena m/c of liquor-flow type to determine the alkali hydrolysis properties of polyester fabrics. The results were as follows: Under the same conditions, the weight loss of charmeuse was about 0.5% and 2~3% higher than that of pebble with CDR m/c and with Sofleena m/c, respectively. The weft density of pebble decreased about 14picks/inch with CDR m/c and 3picks/inch with Sofleena m/c comparing to the untreated sample at 18% of weight loss, while the weft density of charmeuse decreased about 5picks/inch with CDR m/c and 2picks/inch with Sofleena m/c at 20% of weight toss. K/S value decreased almost identically within about 11% weight loss of pebble and 8% of charmeuse processed with both CDR and Sofleena. However, in the above these weight losses, K/S value of the fabrics processed with Sofleena was higher than that of fabrics processed with CDR. The bending rigidity of warp direction of the fabrics ($2{\times}10^{-2}gf.cm^2 /cm$ higher for charmeuse and ($7{\times}10^{-3}gf.cm^2 /cm$ higher for pebble) processed with CDR m/c was higher than that of the fabrics processed with Sofleena m/c.

• Journal of IKEEE
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• v.13 no.2
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• pp.118-125
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• 2009

With recent advancement of high-speed, multi-gigabit data transmission capabilities, transmitters usually send data without clock signals for reduction of hardware complexity, power consumption, and cost. Therefore clock and data recovery circuits(CDR) become important to recover the clock and data signals and have been widely studied. This paper presents the design of 10Gbps CDR in 0.18$\mu$m CMOS process. A quarter-rate bang-bang phase detector is designed to reduce the power and circuit complexity, and a 4-stage LC-type VCO is used to improve the jitter characteristics. Simulation results show that the designed CDR consumes 80mW from a 1.8V supply, and exhibits a peak-to-peak jitter of 2.2ps in the recovered clock. The chip layout area excluding pads is 1.26mm$\times$1.05mm.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.2
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• pp.57-63
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• 2009

In this Paper, a novel 622Mbps burst-mode clock and data recovery (CDR) circuit is proposed for passive optical network (PON) applications. The CDR circuit is composed of CDR(Clock and Data Recovery) block and PLL(Phase Locked Loop) block. Lock dynamics is accomplished on the first data transition and data are sampled in the optimal point. The CDR circuit is realized in 0.35um CMOS process technology. With input pseudo-random bit sequences(PRBS) of $2^7-1$, the simulations show 17ps peak-to-peak retimed data jitter characteristics. The experimental results show that the proposed CDR circuits are operating as expected, recovering an incoming 622Mbps burst-mode input data without errors.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.39 no.5
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• pp.605-612
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• 2019

Traditionally, travel demand forecasts have been conducted based on the data collected by a survey of individual travel behavior, and their limitations such as the accuracy of travel demand forecasts have been also raised. In recent, advancements in information and communication technologies are enabling new datasets in travel demand forecasting research. Such datasets include data from global positioning system (GPS) devices, data from mobile phone signalling, and data from call detail record (CDR), and they are used for reducing the errors in travel demand forecasts. Based on these background, the objective of this study is to assess the feasibility of CDR as a base data for travel demand forecasts. To perform this objective, CDR data collected for Daegu Metropolitan area for four days in April including weekdays and weekend days, 2017, were used. Based on these data, we analyzed the correlation between CDR and travel demand by travel survey data. The result showed that there exists the correlation and the correlation tends to be higher in discretionary trips such as non-home based business, non-home based shopping, and non-home based other trips.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.46 no.1
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• pp.68-75
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• 2009

In this paper, an efficient proposed CDR(Clock and Data Recovery Circuits) using 1/4-rate clock based on dual-interpolator is proposed. The CDR is aimed to overcome problems that using multi-phase clock to decrease the clock generator frequency causes side effects such as the increased power dissipation and hardware complexity, especially when the number of channels is high. To solve these problems, each recovery part generates needed additional clocks using only inverters, but not flip-flops while maintaining the number of clocks supplied from a clock generator the same as 1/2-rate clock method. Thus, the reduction of a clock generator frequency using 1/4-rate clocking helps relax the speed limitation and power dissipation when higher data rate transfer is demanded.

• Journal of the Korean GEO-environmental Society
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• v.20 no.6
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• pp.5-13
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• 2019

The international trend in soil nailed wall design has been evolved from the allowable stress design to limit state design and it is still currently ongoing. The design guidelines in Korea and Hong Kong still adopts the allowable stress design philosophy while those in others mostly do the limit state design. In this study, four soil nail design methods presented in the major design guidelines (U.S. FHWA GEC 7 (2015), Clouterre in France (1991), Soil nailing - best practice guidance in U.K. (CIRIA, 2005), Geoguide 7 in Hong Kong (2008) and Design standard for slope reinforcement work in Korea (KDS 11 70 15 f: 2016)) are described and analyzed in brief. The factor of safety and CDR (Capacity-to-Demand Ratio) which is used to measure the degree of conservatism of a design guide are obtained for the two cases. One is the design example presented in CIRIA (2005) and the other is in-situ loading test performed on the top of backfill of the soil nail wall to investigate the conservatism of design guidelines. It is revealed that the design method in overall stability of soil nail walls in domestic design method (CDR=0.78) is the most conservative and those by Clouterre (CDR=0.99, 1.09), Geoguide 7 (CDR=1.13, 0.97), U.S. FHWA (CDR=1.09, 1.07) and CIRIA (CDR=1.40, 1.16) in order from the second most conservative to the least conservative for the design example presented in CIRIA. For the in-situ loading test performed on the top of backfill of the soil nail wall, the order of conservatism is identical except that the places of Geoguide 7 (CDR=0.66, 0.72) and FHWA (CDR=0.73, 0.72) are changed. However, the results obtained among U.S. FHWA (2015) and Clouterre (1991) and Geoguide 7 (2008) are not so different.

• Therapeutic Science for Rehabilitation
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• v.11 no.2
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• pp.53-62
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• 2022

Objective : This study aimed to present basic data that could help in selecting or using evaluation tools in clinical settings. Methods : This study included 51 patients with stroke. The Cognitive Impairment Screening Test (CIST), Korean-Mini Mental State Examination, 2nd Edition (K-MMSE~2), and Clinical Dementia Rating (CDR) were used as evaluation tools. The correlation between evaluation tool scores was analyzed using Spearman's rank correlation coefficient, and the comparison of total scores between the CIST and K-MMSE~2 according to global CDR scores was analyzed using the Wilcoxon signed-rank test. Results : The correlation between the total CIST and K-MMSE~2 scores and global CDR scores was statistically significant (p<.01). The correlation between the sub-scores of the CIST and K-MMSE~2 showed a statistically significant correlation for all sub-scores (p<.01). The comparison of total scores between the CIST and K-MMSE~2 according to global CDR scores showed no statistically significant differences in all global CDR scores. Conclusion : This study showed that there was a correlation between CIST, K-MMSE~2, and CDR in patients with stroke. In the future, we hope that the results of this study will help to select or use cognitive function evaluation tools in clinical settings.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.27 no.2
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• pp.49-61
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• 1997

The purpose of this study was to compare E-speed film, CDR, and modified CDR images by means of observing some artificial defects of alveolar bone wall in the sound human dried mandibles. High diagnostic accuracy was shown in 1 wall and 4 wall defects by all 5 observers (2 Radiologists, 2 Periodontists, 1 General practitioner), but the diagnosis in 2 wall and 3 wall defects was inaccurate. Modified CDR images had the more diagnostic accuracy than E-speed film and CDR images, but there was no statistical difference among them. Finally, radiologist used modified CDR images more than others and used equalization effect more than the change in contrast and/or brightness.