• ETRI Journal
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• 제35권5호
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• pp.935-938
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• 2013

This letter presents an algorithm for selecting a low delay for the modified discrete cosine transform (MDCT) and inverse MDCT (IMDCT). The implementation of conventional MDCT and IMDCT requires a 50% overlap-add (OLA) for a perfect reconstruction. In the OLA process, an algorithmic delay in the frame length is employed. A reduced overlap window and MDCT/IMDCT phase shifting is used to reduce the algorithmic delay. The performance of the proposed algorithm is evaluated by applying the low-delay MDCT to the G.729.1 speech codec.

• 인터넷정보학회논문지
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• 제2권2호
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• pp.23-36
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• 2001

차별화 서비스(Differentiated Services) 망에서 실시간 멀티캐스트를 지원하기 위해서 EF(Expedite Forwarding) PHB(Per Hop Behavior)를 사용하여 전송한다면 EF PHB와 멀티캐스트 플로우의 특성 때문에 EF 멀티캐스트 플로우가 증가하게 될 경우 망의 관리나 자원 관리가 어렵다. 또한 LBE(Lower Than Best-effort) PHB를 이용한 멀티캐스트 전송은 전송지연을 보장할 수 없다는 단점이 있다. 이러한 문제를 해결하기 위하여 본 논문에서는 AF(Assured Forwarding) PHB를 이용하여, 허용 가능한 홉 당 지연시간 이내에서 처리를 해줄 수 있는 저지연 멀티캐스트(Low-delay Multicast)라는 새로운 PHB를 제안하고, 이를 위한 차별화 서비스 망에서의 핵심요소인 첫 흘 라우터. 내부 라우터. 경계 라우터들의 큐 구조를 설계하고 각 라우터들에서의 큐 관리 및 스케줄링 기법을 설계한다.

• 한국연소학회지
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• 제18권4호
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• pp.12-20
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• 2013

The ignition delay time is an important factor to understand the combustion characteristics of internal combustion engine. In this study, ignition delay times of cool and thermal flame were observed separately in homogeneous charge compression ignition(HCCI) engine. This study presents numerical investigation of ignition delay time of n-heptane and alcohol(ethanol and n-butanol) binary fuel. The $O_2$ concentration in the mixture was set 9-10% to simulate high exhaust gas recirculation(EGR) rate condition. The numerical study on the ignition delay time was performed using CHEMKIN codes with various blending ratios and EGR rates. The results revealed that the ignition delay time increased with increasing the alcohol fraction in the mixture due to a decrease of oxidation of n-heptane at the low temperature. From the numerical analysis, ethanol needed more radical and higher temperature than n-butanol for oxidation. In addition, thermal ignition delay time is sharply increasing with decreasing $O_2$ fraction, but cool flame ignition delay time changes negligibly for both binary fuels. Also, in high temperature regime, the ignition delay time showed similar tendency with both blends regardless of blending ratio and EGR rate.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 추계종합학술대회 논문집(2)
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• pp.91-94
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• 2000

This paper introduces the design of low-power, fast-locking delay locked-loop using complementary pass transistor logic(CPL). Low-power design has become one of the most important in the modem VLSI application. CPL has the advantage of fast speed, high density, and low power with signal buffering between stages. Based on this analysis, we concluded that the I/O performance can be beyond 500㎒, 2-poly, 2-metal 0.65$\mu\textrm{m}$, 3.3V supply.

• 한국음향학회지
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• 제32권6호
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• pp.525-531
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• 2013

본 논문은 파워 상호보완 윈도우를 이용한 지연 감소 알고리즘을 IntMDCT(Integer Modified Discreate Cosine Transform)에 적용하고자 제안한다. 기존에 사용하는 변환 방식인 MDCT는 정수 입력에 대해 실수 값을 출력하므로 데이터의 확장을 야기 시킨다. 이에 정수 대 정수 변환인 IntMDCT 기술이 등장했다. 하지만 IntMDCT는 MDCT(Modified Discreate Cosine Transform)처럼 알고리즘 지연을 갖는 문제점을 가지고 있다. 지연은 실시간 통신을 목표로 하는 환경에 있어 중요한 이슈로 자리 잡고 있다. 이러한 샘플의 지연을 최소화하기 위해 제안하는 알고리즘을 적용하고 성능을 평가한 결과, IntMDCT에서 발생하는 샘플 지연이 절반으로 감소하는 것을 확인 할 수 있었다.

• International Journal of Human Ecology
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• 제1권1호
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• pp.59-77
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• 2000

The purpose of this study was to extend our understanding of the developmental antecedents of delay of gratification in infancy. The first goal was to examine direct effects of one feature of an infants’ temperament and of positive and negative parenting assumed at age one on children’s delay of gratification six months later. The second goal of the study was to test the interactive effect of early infant temperament and parenting on children’s delay of gratification. It was hypothesized that 1) less negative infants at 12 months would delay gratification longer six months later, 2) children of parents who provided more positive and sensitive feedback would delay gratification longer than children with parents who were more negative and less sensitive, and 3) there would be differential prediction of parenting for children who scored high and low in negative emotionality as infants. Toward this end, 81 infants were observed interacting at one year of age with their mothers and fathers during laboratory assessments to obtain measures of parenting and infant negative emotionality. At 18 months of age, the child’s capacity to delay touching attractive objects was measured. The main effects of infant negative emotionality and of mothering on children’s delay of gratification were not detected at standard levels of significance. Differential effects of parenting on children’s delay of gratification for infants with low or high negative emotionality, too, were not detected. However, the anticipated effect of fathering on delay of gratification was found in some analyses, indicating that the more positive fathering children received, the longer they could delay gratification in the laboratory six months later.

• 한국정보전자통신기술학회논문지
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• 제16권2호
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• pp.69-76
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• 2023

MDCT/IMDCT 과정을 사용하는 고품질 오디오/음성 코덱은 이전 프레임 과의 중첩-합(Overlap-add) 과정을 통해 현재 프레임을 완벽 복원 가능하다. 중첩-합 과정에서 프레임 길이 만큼의 알고리즘 지연이 발생하게 된다. 본 논문에서는 알고리즘 지연을 줄이기 위해 MDCT/IMDCT에 가변적인 위상변이를 사용하여 알고리즘 지연을 줄인 MDCT/IMDCT 과정을 제안한다. 가변 지연 MDCT/IMDCT알고리즘을 ITU-T 표준 코덱 G.729.1 코덱에 적용하여 저지연 오디오/음성 코덱을 제안하였다. MDCT/IMDCT 과정에서의 알고리즘 지연은 기존 20 ms에서 1.25ms 까지 감소시킬 수 있다. 저지연 MDCT/IMDCT를 적용한 오디오/음성 코덱의 복호화된 출력신호는 객관적 음질 시험 방법인 PESQ 시험을 통해 성능 평가하였다. 전송 지연이 감소 됨에도 불구하고 기존 방법과 음질 차이가 없음을 확인할 수 있었다.

• 대한원격탐사학회지
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• 제30권2호
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• pp.331-339
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• 2014

지상기반 전리층모델로 계산한 전리층 지연값을 저궤도에서의 전리층 지연값으로 변환하기 위해서는 전리층 변환 배율 적용해야 하는데, 이러한 배율을 IRI 전리층모델을 사용하여 결정하는 기법을 제안하였다. IGS 전리층모델에 전리층 배율을 적용하여 계산한 전리층 지연값을 NASA GRACE 위성의 관측값과 비교하였다. 약 480 km 고도에서 2004년 평균 배율은 0.25이며, 표준편차는 0.01이다. 전리층 배율은 주간에 비해 야간에 상대적으로 증가하며, 계절적으로는 봄, 가을에 높은 값을 가진다. IGS모델에 전리층배율을 결합해서 추정한 저궤도 전리층 지연값 추정 오차 평균은 3.50 TECU이다.

• 한국자동차공학회논문집
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• 제1권1호
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• pp.50-58
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• 1993

The ignition delay of diesel oil and fish oil blended with diesel oils was investigated at various pressure and temperature conditions in a constant volume combustion bomb. The evaporation and combustion duration of diesel oil and fish oil blended with diesel oils were respectively different in high and low temperature. The dependence of ignition delay on the temperature was different in high and low temperature ranges which were divided at the 773K. The dependence of ignition delay on the pressure was almost linear, regardless of the test fuels at the constant temperature(863K). The ignition delay became longer as the blending rate of fish oil increased at the constant temperature and pressure, but it was especially short with 20% fish oil blended with diesel oils.

• Journal of information and communication convergence engineering
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• 제3권3호
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• pp.119-121
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• 2005

This paper aims to estimate the delay time of multiple signals in a multi-path environment. It also seeks to carry out a comparative analysis with the existing delay time under the proposed algorithm to develop a new algorithm that applies the space average method in a MUSIC algorithm. Unlike the existing delay time estimation algorithm, the developed algorithm was able to estimate the delay time in 5ns low. Therefore, the algorithm proposed in this paper improved the existing delay time estimated algorithm.