• 대한교통학회지
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• 제9권2호
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• pp.27-40
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• 1991

Delay is an widely-used tool for evaluating the operation of signalized intersections. This paper presents two mathematical models: a model converting stop delay into approach delay : and a model estimating delay at isolated signalized intersection. To develop the delay-conversion model, actual stop delay and approach delay experienced by individual vehicles were measured and then their relationship was formulated using ma-thematical procedure. the formula expressing the approach-delay to stop-delay ratio was a monotonously decreasing function of effective red time. New delay model was developed based on the following criteria; the fitness to measured delay for undersaturated traffic condition and the convergence to the deterministic overflow delay for oversaturated traffic condition. Performance of this model was better than those of other existing models based on the comparison study.

• Journal of information and communication convergence engineering
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• 제8권4호
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• pp.461-465
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• 2010

This paper describes the design method of Time-to-Digital Converter(TDC) to obtain the constant delay time and good reliability. The reliability property is described with delay elements. In TDC the time signal is converted to digital value which is based on delay elements for the time interpolation. To obtain the constant delay time, the first and the last delay elements have different structure compared to the middle delay elements. In the first and the last delay elements, the driving ability could be controlled for the different delay time. The delay element can be designed by analog and digital devices. The delay time of the element using analog devices is not sensitive to process parameters than that of the element using digital devices. And the TDC circuit by the elements using analog devices shows better reliability than that by the elements using digital devices also.

• 한국전자파학회논문지
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• 제15권3호
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• pp.265-270
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• 2004

본 논문에서는 group delay가 위성 통신 시스템에 미치는 영향을 분석한다. 일정한 상수가 아닌 group delay에서는 신호의 위상 왜곡이 발생한다. Group delay는 특성에 따라 linear, parabolic, cubic으로 모델링할 수 있다. 각각의 group delay 특성을 위성통신 시스템에 적용하여 BER(bit error rate)을 분석한다. Group delay는 신호의 대역폭이 커질수록 신호에 미치는 영향이 커지는 특성을 갖고 있으며, 위성 통신 시스템의 정보 전송속도가 1Mbps, 4Mbps, 8Mbps 의 세 가지인 경우에 대하여 BER을 분석한다. 이때 channel coding으로는 구속장이 7이고, code rate 1/2인 convolution coding과 7/8 punctured convolution coding 를 이용한다. BER = $10^{-5}$을 만족하는 요구 SNR을 관찰하였을 때, group delay의 영향을 받는 데이터는 group delay의 영향을 받지 않은 데이터에 비해 요구 SNR은 최소 0.3㏈에서 최대 4.4㏈으로 증가한다. 이들 중 group delay에 의한 영향이 가장 큰 경우는 group delay의 특성이 linear 특성이고 channel coding이 7/8 puncture convolution coding, 전송속도가 8 Mbps인 경우로서 이때 요구 SNR은 4.4㏈증가한다.

• Journal of information and communication convergence engineering
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• 제8권1호
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• pp.103-106
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• 2010

In this paper, the delay times were evaluated to develop highly reliable time-to-digital converter(TDC) in analog and digital delay element structures. The delay element can be designed by using current source or inverter. In case of using inverter, the number of inverter has to be controlled to adjust the delay time. And in case of using current source, the current for charging and discharging is controlled. When the current source is used the delay time of the delay element is not sensitive with varying the channel width of CMOS. However, when the inverter is used the delay time is directly related to the channel width of CMOS. Therefore to obtain good reliability in TDC circuit the delay element using current source is more stable compared to inverter in the viewpoint of the variation of fabrication process.

• Current Optics and Photonics
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• 제2권1호
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• pp.34-38
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• 2018

An X-band microwave photonic (MWP) filter using switch-based fiber-optic delay lines has been proposed and experimentally demonstrated. It is composed of two electro-optic modulators (EOMs) and $2{\times}2$ optical MEMS-switch-based fiber-optic delay lines. By changing time-delay difference and coefficients of each wavelength signal by using fiber-optic delay lines and an electro-optic modulator, respectively, a bandpass filter or a notch filter can be implemented. For an X-band MWP filter with four channel elements, fiber-optic delay lines with the unit time-delay of 50 ps have been experimentally realized and the frequency responses corresponding to the time-delays has been measured. The measured frequency response error at center frequency and the time-delay difference error were 180 MHz at 10 GHz and 3.2 ps, respectively, when the fiber-optic delay line has the time-delay difference of 50 ps.

• Journal of Electrical Engineering and information Science
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• 제2권3호
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• pp.14-21
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• 1997

In delay-optimized designs, timing failures due to manufacturing delay defects are more likely to occur because the average timing slacks of paths decrease and the system becomes more sensitive to smaller delay defect sizes. In this paper, the impact of delay optimized logic circuits on delay fault testing will be discussed and compared to the case for non-optimized designs. First, we provide a timing optimization procedure and show that the resultant density function of path delays is a delta function. Next we also discuss the impact of timing optimization on the yield of a manufacturing process and the defect level for delay faults. Finally, we will give some recommendations on the determination of the system clock time so that the delay-optimized design will have the same manufacturing yield as the non-optimized design and on the determination of delay fault coverage in the delay-optimized design in order to have the same defect-level for delay faults as the non-optimized design, while the system clock time is the same for both designs.

• Journal of electromagnetic engineering and science
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• 제12권2호
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• pp.166-170
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• 2012

This paper presents a tunable composite right/left-handed (CRLH) delay line for a delay line discriminator that linearizes modulated frequency sweep in a frequency modulated continuous wave (FMCW) radar transmitter. The tunable delay line consists of 8 cascaded unit cells with series varactor diodes and shunt inductors. The reverse bias voltage of the varactor diode controlled the group delay through its junction capacitance. The measured results demonstrate a group delay of 8.12 ns and an insertion loss of 4.5 dB at 250 MHz, while a control voltage can be used to adjust the group delay by approximately 15 ns. A group delay per unit cell of approximately 1 ns was obtained, which is very large when compared with previously published results. This group delay can be used effectively in FMCW radar transmitters.

• 한국정보과학회논문지:시스템및이론
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• 제29권6호
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• pp.354-360
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• 2002

지연시간 계산은 지연시간을 고려한 배치 단계에서 백만 번 이상도 수행되므로 효과적이면서 간단해야 한다. 본 논문에서는 계산은 매우 빠르고 간단하지만 수 백%의 오차를 가질 수 있는 Elmore delay를 개선하기 위해 Elmore delay와 SPICE 결과의 비율을 보상값으로 이용하는 방법을 제안한다. 제안한 새로운 방법은 resistance shielding effects를 고려하여 실험적으로 지연시간을 보상하여 그 오차를 크게 줄이며, 계산 복잡도는 Elmore delay와 같은 정도로 간단하다. Elmore delay가 31.6 ~ 145.2% 오차를 갖는 RC 트리에 대하여 실험한 결과, 보상된 delay의 오차는 2.5 ~ 22.7%로 크게 줄었다.

• 가정과삶의질연구
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• 제24권3호
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• pp.15-25
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• 2006

This study has been performed to identify intelligent ability, reward choice in assumed situation of delay of gratification, and delay of gratification ability. The subjects for this study were 100 preschoolers between the ages of 4 and 5, their mothers, and 15 teachers of three day-care centers in Seoul. T-test, F-test, Correlation analysis and multiple regression analysis were used for data analysis. The main results of this study were as follows: First, preschoolers' delay of gratification ability by mothers' educational background was significant and delay of gratification ability by sex was significant. This means that mothers who had a higher educational background were positively related to preschoolers' delay of gratification ability. Second, in an assumed situation of delay of gratification, preschoolers' delay of gratification ability by reward choice was not significant. Third, delay of gratification by intelligent ability was significant. Fourth, the correlation among intelligent ability, reward choice in assumed situation of delay of gratification and delay of gratification ability were significant. Finally, preschoolers' delay of gratification ability was significantly influenced by two factors: reward choice in assumed situation of delay of gratification and preschoolers' intelligent ability.

• 한국건축시공학회지
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• 제9권1호
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• pp.89-94
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• 2009

A study was performed the analysis for the schedule delay of the public housing. To perform this study, the first study existing research literature on the cause of the schedule delay was considered. The based on existing study, this study selected the cause of schedule delay. For check of the schedule delay, this study was compared the monthly schedule and the work diary. Survey was conducted for using the selected cause of schedule delay. And the importance was calculated for using the AHP method. In a case site, the cause of the schedule delay was analyzed. The last, the delay cause was presented the map of cause of effect the based on the delay cause of a case site.