• Proceedings of the KSR Conference
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• 한국철도학회 2003년도 춘계학술대회 논문집
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• pp.251-256
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• 2003

This study focuses on the development of the conceptual criteria which could be applied to the speed-up strategy of urban rail operation. Down town segment or not, and peak hour or not are the criteria. The author suggests that in the case of down town segment and peak hour urban rail should take the all-stop pattern, if down town segment and off peak hour, then skip-stop pattern, if not-down town segment and peak hour, the A, B skip-stop, and if not-down town segment and off peak hour, the A, B, C skip-stop. If side lines, three rail, or 2 double lines, then express train operation is recommended in the peak hour. Then this study recommends speed-up strategies of each 8 urban lines.

• Proceedings of the KSR Conference
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• 한국철도학회 2002년도 춘계학술대회 논문집
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• pp.135-141
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• 2002

Recently, in the metro railways, researches on the skip-stop operation and development of the double deck train-set are active, which is to improve the service quality through reducing the passenger travel time and suppling seating service. Constructing new line or reforming the existent line needs huge amount of budget. Therefore, previous to start these large scale projects, scrutiny on benefit improvement, cost reduction and those optimal trade-off is indispensable. In this paper, a quantitative analysis to determine the optimal train service patterns and train-sets necessary is proposed, under the skip-stop operation condition in the metro railways. The analysis models are formulated in mathematical programming model, and tested validity using the LINGO 7.0.

• Speech Sciences
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• 제13권3호
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• pp.19-33
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• 2006

This study explores whether Russian, known to have a process of syllable-final devoicing, reveals differences in vowel duration as a function of the underlying voicing of the coda stop. This paper also examines whether non-native speakers of Russian and English learn typical L2 values in vowel duration. The results indicate that vowels in Russian have a slightly longer mean duration before a voiced stop than before a voiceless stop (a mean difference of 9.52 ms), but in most cases the differences did not exhibit statistical significance. In English the mean difference was 60.05 ms, and the differences were in most cases statistically significant. All native Russian speakers of English produced larger absolute differences in vowel duration for English than for Russian, and all native English speakers of Russian produced smaller absolute differences for Russian than for English. More experienced learners seemed to achieve more native-like values of vowel duration than less experienced learners did, suggesting that learning occurs gradually as the learners gain more experience with the L2.

• Transactions of the Korean Society of Automotive Engineers
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• 제10권5호
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• pp.206-213
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• 2002

This paper proposes a vehicle trajectory prediction method for application to vehicle-to-vehicle distance control. This method is based on 2-dimensional kinematics and a Kalman filter has been used to estimate acceleration of the object vehicle. The simulation results using the proposed control method show that the relative distance characteristics can be improved via the trajectory prediction method compared to the customary vehicle stop and go cruise control systems which makes the vehicle remain at a safe distance from a preceding vehicle according to the driver's preference, automatically slow down and come to a full stop behind a preceding vehicle.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.557-560
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• 2000

Combination of SDB(Si-wafer Direct Bonding) and electrochemical etch-stop in TMAH anisotropic etchant can be used to create a variety of MEMS(Micro Electro Mechanical System). Especially, fabrication of SDB SOI structures using electrochemical etch-stop is accurate method to fabrication of 3D(three-dimensional) microstructures. This paper describes on the fabrication of SDB SOI structures with sealed cavity for MEMS applications and thickness control of active layer on the SDB SOI structure by electrochemical etch-stop. The flatness of fabricated SDB SOI structure is very uniform and can be improved by addition of TMAH to IPA and pyrazine.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 한국전기전자재료학회 2000년도 추계학술대회 논문집
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• pp.583-586
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• 2000

The non-selective method by polishing after grinding was used widely to thinning of SDB SOI structures. This method was very difficult to thickness control of thin film, and it was dependent on equipments. However electrochemical etch-stop, one of the selective methods, was able to accurately thickness control and etch equipment was very simple. Therefore, this paper described with the effect of leakage current and electrodes on electrochemical etch-stop. Consequentially, PP(passivation potential) was changed according to the kinds of contact and contact sizes, but OCP(open current potential) was not change with range of -1.5~-1.3V

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 한국전기전자재료학회 2000년도 추계학술대회 논문집
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• pp.579-582
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• 2000

This paper described on the fabrication of SOI(Si-on-insulator) structures with buried cavities by SDB technology and eletrochemical etch-stop. The cavity was fabricated the upper handling wafer by Si anisotropic etch technique. SDB process was performed to seal the fabricated cavity under vacuum condition at -760mmHg. In the SDB process, captured air and moisture inside of the cavities were removed by making channels towards outside. After annaling(100$0^{\circ}C$, 60 min.), the SDB SOI structure was thinned by electrochemical etch-stop. Finally, it was fabricated the SDB SOI structure with buried cavities as well as an accurate control and a good flatness.

• The Journal of the Society of Korean Medicine Diagnostics
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• 제14권2호
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• pp.1-12
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• 2010

The form of intermittent pulse(代脈) has three standards. The first is "The persistence of the pulse stop(止不能還)". This standard is extensively accepted to the medical scientists in every ages of after the . The second is "The replacement of the former pulses(更代)". This standard is very useful to explain the situations that the intermittent pulse(代脈) is regarded as a dead pulse(死脈). The third is "The regular inerval of the pulse stop(止有定數)". This standard is impractical and illogical to practical using of the intermittent pulse(代脈). The reason is misreading on the of Wang-Suk-Hwa(王淑和) and the inexact & expansive reproduction of medical men of the Myeong-Chung dynasty(明淸代).

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• 제13권5호
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• pp.431-436
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• 2000

This paper describes on the fabrication of a SOI substrate by SDB technology and electrochemical etch-stop. The surface of the thinned SDB SOI substrate is more uniform than that of grinding or polishing by mechanical method and this process was found to be a very accurate method for SOI thickness control. During electrochemical etch-stop leakage current versus voltage curves were measured for analysis of the open current potential(OCP) point the passivation potential(PP) point and anodic passivation potential. The surface roughness and the controlled thickness selectivity of the fabricated a SDB SOI substrate were evaluated by using AFM and SEM respectively.

• Phonetics and Speech Sciences
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• 제15권4호
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• pp.11-16
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• 2023

The present study examines how a cognitive attention affects Korean learners of English (L2) in perceiving the English stop voicing distinction (/d/-/t/). This study tested the effect of attentional distractor on primary and non-primary acoustic cues, focusing on the role of Voice Onset Time (VOT) and fundamental frequency (F0). Using the dual-task paradigm, 28 Korean adult learners of English participated in the stop identification task carried with (distractor) and without (no-distractor) arithmetic calculation. Results showed that when distracted, Korean learners' sensitivity to VOT decreased as priorly reported with native English speakers. Furthermore, as F0 is a primary cue for a L1 Korean stop laryngeal contrast, its role in L2 English voicing distinction was also affected by a distractor, without compensating for the reduced VOT sensitivity. These findings suggest that flexible use of multiple cues in L1 is not necessarily beneficial for L2 phonological processing when coping with a adverse listening condition.