• ETRI Journal
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• 제30권4호
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• pp.495-505
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• 2008

This paper presents a parallel processing searcher structure for the initial synchronization of a direct sequence ultra-wideband (DS-UWB) system, which is suitable for the digital implementation of baseband functionalities with a 1.32 Gsample/s chip rate analog-to-digital converter. An initial timing acquisition algorithm and a data demodulation method are also studied. The proposed searcher effectively acquires initial symbol and frame timing during the preamble transmission period. A hardware efficient receiver structure using 24 parallel digital correlators for binary phase-shift keying DS-UWB transmission is presented. The proposed correlator structure operating at 55 MHz is shared for correlation operations in a searcher, a channel estimator, and the demodulator of a RAKE receiver. We also present a pseudo-random noise sequence generated with a primitive polynomial, $1+x^2+x^5$, for packet detection, automatic gain control, and initial timing acquisition. Simulation results show that the performance of the proposed parallel processing searcher employing the presented pseudo-random noise sequence outperforms that employing a preamble sequence in the IEEE 802.15.3a DS-UWB proposal.

• 정보처리학회논문지D
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• 제17D권5호
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• pp.337-346
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• 2010

Timing diagram은 시간에 따른 시스템의 행동을 표현하기 용이하고 표현된 행동을 쉽게 인식할 수 있는다는 장점 때문에 널리 사용되고 있다. Timing diagram으로 기술된 시스템을 테스트 하기 위해서는 여러 기술이 필요하다. 그 중의 하나는 테스트 케이스 목표들이 존재할 때, 시스템 모델이 원하는 상태에 도달하도록 하기 위해 입력 값들의 시퀀스를 생성하는 기술이다. 본 논문은 Timing diagram모델에 대한 테스트 케이스 목표로부터 테스트 입력 시퀀스를 자동으로 생성하는 방법을 제안한다. Timing diagram에서 테스트 입력 시퀀스를 자동으로 생성하기 위해서는 입력 waveform과 시간 제약으로 이루어진 시점의 전이 조건을 만족시키는 적절한 입력 집합을 필요로 한다. 이와 같은 문제를 해결하기 위해, 본 논문에서는 선형 계획법을 이용한 접근 방식을 택하였는데, 해결과정은 다음과 같다. 1) Timing diagram 모델을 입력으로 받아 이를 선형 계획 문제로 변형한다. 2)변형된 선형 계획 문제를 선형 문제 해결 도구를 사용하여 해결한다. 3) 선형 계획 문제의 해답으로부터 Timing diagram모델의 테스트 입력 시퀀스를 생성한다. 본 논문에서는 임의의 Timing diagram 모델에 대해 이를 선형 계획법으로 모델링 하는 방법을 형식적으로 기술하였고, 증명을 통해 본 논문의 접근 방법의 타당성을 보였으며, 또한 도구를 구현하여 Timing diagram 예제 모델로부터 테스트 입력 시퀀스를 생성함으로써 본 논문의 유용성을 입증하였다.

• 한국경영과학회지
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• 제24권2호
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• pp.69-80
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• 1999

A genetic algorithm to determine the optimal signal sequence and double cycle pattern is described. The signal sequence and double cycle pattern are used as the input for TRANSYT to find optimal signal timing at each junction in the area traffic networks, In the genetic process, the partially matched crossover and simple crossover operators are used for evolution of signal sequence and double cycle pattern respectively. A special conversion algorithm is devised to convert the signal sequence into the link-stage assignment for TRANSYT. Results from tests using data from an area traffic network in Leicester region R are given.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2007년도 하계종합학술대회 논문집
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• pp.53-54
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• 2007

As Cable Network is developing for 2-way high speed data service, it should be developed to transfer high speed data using limited bandwidth. If QAM is using for this, synchronization algorithms become important system parameters. In this paper, we present two methods of coarse timing recovery using CAZAC sequence for cable modem uplink.

• Imaging Science in Dentistry
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• 제40권3호
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• pp.131-135
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• 2010

Purpose : The aim of this study was to investigate the timing and sequence of eruption of permanent canine and premolars, and to evaluate tooth calcification stage on emergence in Korean children. Materials and Methods : The sample was comprised of 1,266 children (male 720, female 546) aged from 7-13 years. Tooth eruption and calcification stages were determined through oral and panoramic radiographic examination, respectively. Probit analysis was used to calculate the timing of tooth eruption and tooth calcification stage from these cross-sectional data. Results : In both males and females, eruption occurred around the time when one third of tooth root or more was formed. The sequence was as follows: first premolar, canine, and second premolar in maxilla, and canine, first premolar and second premolar in mandible. Tooth eruption occurred earlier in girls compared with boys, averaging 0.63 years. Conclusions : Eruption sequence is identical in males and females with a trend for females to erupt earlier than males. Tooth eruption becomes earlier over the past decades in Korean children.

• ETRI Journal
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• 제37권2호
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• pp.406-416
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• 2015

Timing plays a key role in expressing the qualitative aspects of a character's motion; that is, conveying emotional state, personality, and character role, all potentially without changing spatial positions. Temporal editing of locomotion style is particularly difficult for a novice animator since observers are not well attuned to the sense of weight and energy displayed through motion timing; and the interface for adjusting timing is far less intuitive to use than that for adjusting pose. In this paper, we propose an editing system that effectively captures the timing variations in an example locomotion set and utilizes them for style transfer from one motion to another via both global and upper-body timing transfers. The global timing transfer focuses on matching the input motion to the body speed of the selected example motion, while the upper-body timing transfer propagates the sense of movement flow - succession - through the torso and arms. Our transfer process is based on key times detected from the example set and transferring the relative changes of angle rotation in the upper body joints from a timing source to an input target motion. We demonstrate that our approach is practical in an interactive application such that a set of short locomotion cycles can be applied to generate a longer sequence with continuously varied timings.

• 디지털콘텐츠학회 논문지
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• 제6권1호
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• pp.41-48
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• 2005

잡음환경이 열악하고 대역폭이 부족한 HFC 망 상향채널에서 보다 나은 대칭형 멀티미디어 서비스를 제공할 수 있는 S-DMT 방식의 상향 채널 케이블모뎀을 위한 심볼 타이밍 복원 알고리즘을 제안하고 그에 대한 성능을 평가하였다. 타이밍 복원 알고리즘은 시간 영역에 PN 시퀀스를 삽입하는 방식을 제안하였으며 AWGN, ISI, 및 임펄스 잡음 환경에서 시뮬레이션을 통해 성능을 평가 하였다. 성능 평가 결과, PN 시퀀스 삽입 알고리즘에 의한 타이밍 복원방식은 잡음 환경에 따라 타이밍 추정 성능이 매우 달라지며, 동일한 샘플링 클럭 오프셋에서 AWGN, ISI, 및 임펄스 잡음이 함께 존재하는 채널일 경우가 임펄스 잡음 채널 경우보다 타이밍 실패 확률이 $10^3$일 때의 Eb/No가 10dB 이상 열화되나 초기부터 샘플링 클럭 오프셋을 보정하여 최적화한 경우 잡음환경에 의한 성능차이가 있으나 비교적 양호한 타이밍 추정 성능을 보임을 확인 하였다.

• 음성과학
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• 제12권4호
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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.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권11호
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• pp.4268-4289
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• 2020

Advanced traffic signal timing method plays very important role in reducing road congestion and air pollution. Reinforcement learning is considered as superior approach to build traffic light timing scheme by many recent studies. It fulfills real adaptive control by the means of taking real-time traffic information as state, and adjusting traffic light scheme as action. However, existing works behave inefficient in complex intersections and they are lack of feasibility because most of them adopt traffic light scheme whose phase sequence is flexible. To address these issues, a novel adaptive traffic signal timing scheme is proposed. It's based on actor-critic reinforcement learning algorithm, and advanced techniques proximal policy optimization and generalized advantage estimation are integrated. In particular, a new kind of reward function and a simplified form of state representation are carefully defined, and they facilitate to improve the learning efficiency and reduce the computational complexity, respectively. Meanwhile, a fixed phase sequence signal scheme is derived, and constraint on the variations of successive phase durations is introduced, which enhances its feasibility and robustness in field applications. The proposed scheme is verified through field-data-based experiments in both medium and high traffic density scenarios. Simulation results exhibit remarkable improvement in traffic performance as well as the learning efficiency comparing with the existing reinforcement learning-based methods such as 3DQN and DDQN.

• 한국운동역학회지
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• 제13권2호
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• pp.139-160
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• 2003

The purpose of this study was to suggest the guideline for scientific and quantitative skill acquisition methods of badminton smashing so that the novice could learn the motions of badminton smashing efficiently. The subject participated consisted of total 6 middle school students of the stilled(3) and the unskilled(3). The cinematographical experimental & Analysis equipments used in the study were composed of two Model D-5100 Video Cameras, a control point, a synchronization timer and Kwon3d motion analysis system. The conclusions obtained were as follows, 1. It was necessary for the unskilled to learn the smashing impact phase in situation of max. velocity of COG in order to minimize the timing loss phase. 2. Particularly. The power from segments of Power Zone must participate in utilization in sequence of order of trunk-upper arm- forearm-hand-racket segment in both the skilled and the unskilled.. 3. Therefore it was necessary for the unskilled to do smashing practice for cumulated sum of absolute & relative velocity transfer into shuttle cock after adjusting anterior-posterior tilting angle and max timing, in sequence of segment recruited.