• Proceedings of the KIEE Conference
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• 2002.11c
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• pp.601-604
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• 2002

In this paper, the timing do-skew modeling for a high speed logic tester channels is developed. The time delay of each channel in a logic tester are different from other channels and it can produce timing error in a test. To get the best timing accuracy in the test with a logic tester, the timing skew must be compensated. The timing skew of channels is due to the difference of time delay of pin-electronics devices composing channels and length of metal line placed on PCB. The expected timing difference of channels can be calculated according to the specifications of pin electronics devices and strip line modeling of PCB. With the calculated delay time, the timing skew compensation circuit has been designed. With the timing skew compensation circuit, the timing calibration of a logic tester can be peformed easily and automatically without other time measuring instruments. The calibration method can then be directly applied to logic testers in mass production lines.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.2
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• pp.46-54
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• 2007

In this paper, we introduce the performance of improved symbol timing detection by the superposed difference type symbol timing detection method in the OFDM system. Also, we represent the maximum detection probability of symbol synchronization timing at each received delay signal in multipath channel delay profile in the correlation and difference type symbol timing detection methods. The computer simulation results show that the correlation symbol timing detection method have maximum detection probability at the lead of the nth received delay signal of highest amplitude, but the difference type symbol timing detection method always have maximum detection probability at the lead of the first received delay signal in the channel delay spread of $70nsec{\sim}217nsec$. The simulation results indicate the possibility of the perfect detection of OFDM symbol synchronization timing and it fit well with the results of improved S/N to the eb/n0 and the performance of symbol timing detection of the proposed method.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.2
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• pp.55-61
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• 2007

In this paper, we represent the maximum detection probability formulas of symbol synchronization timing at each received delay signal in multipath channel delay profile in the multiplied correlation and difference type correlated symbol synchronization timing detection method. The computer simulation results show that the correlation symbol timing detection method have maximum detection probability at the lead of received delay signal of highest amplitude, but the difference type of correlation symbol timing detection method always have maximum detection probability at the lead of first received delay signal in the multipath channel models. Using this results, we show the BER characteristics difference between the IEEE802.11a OFDM signals which is obtained in case of the symbol synchronization timing is taken at zero error(perfect) timing position and at -1 sample error symbol timing position from perfect timing position in the multipath channel models regardless the length of channel delay spread.

• Journal of Advanced Marine Engineering and Technology
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• v.27 no.1
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• pp.117-123
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• 2003

In a bi-fuel engine using gasoline and LPG fuel, with the current ignition timing for gasoline being used, the effective performance could not be taken in LPG fuel supply mode. The ignition timing in LPG fuel mode must be advanced much more than that of gasoline mode for the compensation of its lower flame speed, due to engine torque drop. This study aims to develop the control system for ignition spark timing conversion which is composed of hardwares and control algorithm for gasoline/LPG engine. We propose the control system which can advance the ignition spark timing in LPG fuel mode more than used in gasoline fuel mode. The advance of ignition timing is achieved by change of the ignition dwell time of coil igniter. The engine torque and F/E(Fuel-Economy) in LPG fuel mode are measured to evaluate the difference of engine performance between before and alter changing ignition spark timings. The engine torque and F/E are increased respectively, which proves the developed control system is effective so much for gasoline and LPG bi-fuel engine.

• Speech Sciences
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• v.12 no.4
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• pp.95-112
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• 2005

We investigate Korean learners' speech-timing of English before and after instruction in comparison with native speech, in an attempt to resolve disagreements in the literature as to whether speech-timing is measurable (Lehiste, 1977; Roach, 1982; Dauer, 1983 vs. Low et al., 2000; Yun 2002; Jian, 2004). We measured the pair-wise variability between the adjacent stressed and unstressed syllables within a foot as well as that among adjacent feet in approximately 555 English sentences, which were read by 29 native speakers and 41 Korean learners in the intermediate proficiency level. The results show that in comparison with native American English, Korean learner speech is before instruction significantly (p<.001) smaller for the pair-wise variability between the adjacent stressed and unstressed syllables within a foot; and significantly (p=.01) bigger for the variability among adjacent feet within the utterance. The learner speech after instruction showed significant (p=.01) improvement in the pair-wise variability of syllable sequence toward native speech values. The variability among adjacent feet was progressively smaller for learner speech before and after instruction and for native speech (p=.03). We thus conclude that the speech timing difference between Korean English and American English is measurable in terms of the duration. of stressed and unstressed syllables and that the latter is stress-timed and the former is syllable-timing interfered.

• Proceedings of the KIEE Conference
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• 1987.07b
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• pp.950-953
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• 1987

A wave difference method(WDH) phase detector for timing recovery is designed in the digital subscriber loop receiver. This paper describes the architecture and experimental results of the WDM, tankless timing extraction PLL. The results show that the designed WDM timing extraction circuit have stable jitter performance without the use of high precision LC tank circuit.

• Management & Information Systems Review
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• v.33 no.2
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• pp.225-239
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• 2014

An effect of reward program related to promotional activity has the limitation of being concentrated on a short-term performance or of inducing temporary re-purchase. Accordingly, this study verified the influence of reward method upon consumers' response recovery centering on interactive effects of reward timing and reward intensity, in order to expand a research of dissatisfaction situation. As for the objective of this study, first, the aim is to verify the difference in the influence of economic, non-economic, and combined rewards, which are reward methods of dissatisfaction situation, upon consumers' cognitive response recovery and emotional response recovery. Second, the aim is to confirm a moderating role of reward timing and reward intensity in the effect of consumers' response recovery according to reward methods. To design a research, the perfect factor design between subjects in 3X2X2 was used. As a result of major research, first, there was a difference in the influence upon consumers' response recovery depending on reward methods. Second, the influence of reward method upon consumers' response recovery had a difference depending on reward timing. Third, the influence of reward method upon consumers' response recovery had a difference depending on reward intensity. Consumers' response recovery level was confirmed to have the greatest influence in the combined reward. This study has a significance in newly applying the reward timing, in the dissatisfaction situation which is addressed in the general reward program. Through this study, the aim was to support the empirically analytical results of prior researches and to expand its role in several angles.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.11A
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• pp.1864-1871
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• 2001

In this paper, new symbol timing recovery algorithm is proposed, which is suitable for the digital communication system with Multi-level PAM signals. In the newly proposed symbol timing recovery algorithm, the timing error function is derived by compensating the several difference values between sampled symbol and neighboring symbol every symbol period with mid samples and decided symbol values. Conventional symbol timing recovery methods did not work well in Multi-level PAM signals, but the newly proposed method can be applied to Multi-level PAM signals as well as QPSK. For the performance analysis, the derived variance of the timing error function and the timing error characteristics of S-curve show that the proposed method has better performance than Gardner method and the modified Gardner method.

• Journal of Korean Neurosurgical Society
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• v.66 no.4
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• pp.438-445
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• 2023

Objective : Preoperative transarterial embolization (TAE) of tumor feeders in hypervascular spine metastasis is known to reduce intraoperative estimated blood loss (EBL) during surgery. The effect of TAE varies for several reasons, and one controllable factor is the timing between embolization and surgery. However, the adequate timing remains unclear. This study aimed to evaluate the timing and other factors that reduce EBL in spinal metastasis surgery through a meta-analysis. Methods : A comprehensive database search was performed to identify direct comparative studies of EBL stratified by the timing of surgery after TAE for spinal metastasis. EBL was analyzed according to the timing of surgery and other factors. Subgroup analyses were also performed. The difference in EBL was calculated as the mean difference (MD) and 95% confidence interval (CI). Results : Among seven studies, 196 and 194 patients underwent early and late surgery after TAE, respectively. The early surgery was defined as within 1-2 days after TAE, while the late surgery group received surgery later. Overall, the MD in EBL was not different according to the timing of surgery (MD, 86.3 mL; 95% CI, -95.5 to 268.1 mL; p=0.35). A subgroup analysis of the complete embolization group demonstrated that patients who underwent early surgery within 24 hours after TAE had significantly less bleeding (MD, 233.3 mL; 95% CI, 76.0 to 390.5 mL; p=0.004). In cases of partial embolization, EBL was not significantly different regardless of the time interval. Conclusion : Complete embolization followed by early spinal surgery within 24 hours may reduce intraoperative bleeding for the patients with hypervascular spinal metastasis.

• Journal of Korean Physical Therapy Science
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• v.7 no.2
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• pp.607-613
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• 2000

Objective: This study is designed to examine how an application of a kinesio taping to the foot drop of a hemiplegic patient affects the functional recovery of a gait. Method: The patient was a man with left hemiplegia of about 11 months' duration. a single subject design (ABAB design) was used to investigate the timing difference at a stance phase between an unaffected side and an affected side in the gait ability of the hemiplegic patient by using the kinesio taping. The study was divided into four phase: an initial base-line, an experimental, a second base-line, and second experimental phase. Result: The timing difference at a stance phase between an unaffected side and an affected side in the gait was decreased in the case of the affected side by following the result of applying the kinesio taping to a lower extremity. Conclusion: The kinesio taping applied to the foot drop of a hemiplegic patient affects the improvement of the gait ability.