• Title/Summary/Keyword: phasing

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Phasing Procedure with Automatic Identification in the ARQ mode of the NBDP (NBDP시스템의 ARQ모드에 있어서 자동식별 위상동기)

  • 이흥기;김기문
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.2 no.1
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    • pp.79-85
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    • 1998
  • The 9-digit MMSI(Maritime Mobile Service Identity) in the NBDP is converted to the 7-digit identity signal, used to identify to the phase of and to synchronize to the clock of the ISS(Information Sending Station) automatically for phasing procedure between radio stations. In this paper, algorithms for the automatic identification phasing procedures and for conversions, calculations between 7-signals and 9-identity, those check-numbers in the phasing procedures for calling of the NBDP are discussed and designed. And a method of the faster locking and phasing for calling than that of recommended by ITU-R is suggested and implemented.

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An Analysis of Mid-Course Correction Maneuvers according to Launch-Vehicle Dispersion in Earth-Moon Phasing-Loop Trajectory (지구-달 위상전이궤적에서 발사체 투입오차가 중간경로수정기동에 미치는 영향 분석)

  • Choi, Su-Jin;Lee, Dong-Hun;Suk, Byong-Suk;Min, Seung-Yong;Rew, Dong-Young
    • Journal of Aerospace System Engineering
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    • v.10 no.4
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    • pp.35-40
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    • 2016
  • Mid-course correction maneuvers (MCCMs) are necessary to correct the launch-vehicle dispersion to go to the Moon. There were 3 or 4 MCCMs needed for a direct transfer trajectory. But the strategy for MCCMs of the phasing-loop trajectory is different, because it has a longer trans-lunar trajectory than direct transfer does. An orbiter using a phasing-loop trajectory has several rotations of the Earth, so the orbiter has several good places, such as perigee and apogee, to correct the launch-vehicle dispersion. Although launch dispersion is relatively high, the launch vehicle is not as accurate as we expected. A good MCCM strategy can overcome the high dispersion by using small-magnitude correction maneuvers. This paper describes the phasing-loops sequence and strategy to correct high launch-vehicle dispersions.

Measurement of the ICRH antenna phasing using antenna strap probe based diagnostic system in EAST tokamak

  • Liu, L.N.;Liang, Q.C.;Yang, H.;Zhang, X.J.;Yuan, S.;Mao, Y.Z.;Zhang, W.;Zhu, G.H.;Wang, L.;Qin, C.M.;Zhao, Y.P.;Cheng, Y.;Zhang, K.
    • Nuclear Engineering and Technology
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    • v.54 no.10
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    • pp.3614-3619
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    • 2022
  • To operate the ion cyclotron resonance heating (ICRH) antennas in a better heating state and produce relatively low impurities, it is necessary to control the antenna spectrum by changing the antenna phasing. As the electrical length of the antenna feeding transmission lines is changing as a matter of the standing wave pattern at the ceramic supports, 90° elbows, T-connectors and antenna loops, we chose to measure the current at the grounding points of the antenna loops by antenna strap probe. The voltage drops along a small, several millimeter-long paths at the end of the antenna loops give a signal that is proportional to the current in the antenna loop. Through the simulation of the antenna strap probe and the actual measurement of the antenna phasing under vacuum conditions, the reliability of the antenna strap probe based diagnostic system have been successfully proved. Moreover, this system was successfully applied to the ICRH daily experiments in the spring of 2021. In the near future, the active real-time feedback control of the antenna phasing system will be developed based on this diagnostic system in the EAST tokamak.

Effects of Hydrogen Ratio on Combustion and Emissions Characteristics of Hydrogen/Diesel Dual-Fuel Engine (수소의 혼합 비율에 따른 수소/디젤 혼소 엔진의 연소 및 배기 특성 파악)

  • Park, Hyunwook;Bae, Choongsik
    • 한국연소학회:학술대회논문집
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    • 2014.11a
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    • pp.103-106
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    • 2014
  • The effects of hydrogen ($H_2$) ratio on combustion and emission characteristics in a $H_2/diesel$ dual-fuel engine were investigated. Dual-fuel strategy was applied to improve the control of combustion phasing. The combustion phasing was retarded with increasing $H_2$ fraction. This can be explained by both reduced diesel concentration and chemical effect of $H_2$, which reduce the heat release rate during the low temperature reaction stage. Hydrocarbon and carbon monoxide emissions of the engine were decreased drastically when $H_2$ ratio was increased.

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A Program for Efficient Phasing of Three-Generation Trio SNP Genotype Data

  • Song, Sang-Hoon;Kim, Sang-Soo
    • Genomics & Informatics
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    • v.9 no.3
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    • pp.138-141
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    • 2011
  • Here, we report a computer program written in Python, which phases SNP genotypes and infers inherited deletions based on the pattern of Mendelian inheritance within a trio pedigree. When tiered trio genotypes that encompass three generations are available, it narrows a recombination event down to a region between two consecutive heterozygous markers. In addition, the phase information that is inferred from the upper trio that is formed by one of the parents and grandparents can be propagated to phase the genotypes of the lower trio that is formed by the parents and an offspring.

Demand-feeding and Locomotor Circadian Rhythms in the Red sea bream, Pagrus major

  • Choe Yong-Gwon;Choi Jae-Eun;Roh Duk-Whan;Choi Cheol-Young
    • Fisheries and Aquatic Sciences
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    • v.4 no.3
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    • pp.130-137
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    • 2001
  • In the present study, the locomotor and feeding activities of single red sea bream, Pagrus major were simultaneously investigated to examine the existence of such dual behaviour. Seven red sea bream of 13cm body length on average were placed individually in 35L tanks equipped with an infrared sensor and a newly developed demand-feeding device. Fish were exposed to a light: dark 12: 12h cycle and constant darkness (DD) to study endogenous rhythmicity. Under LD 12: 12 h, the daily pattern of behaviour differed between individual fish; some red sea bream were diurnal and others were nocturnal. Futhermore, some of them displayed an extraordinary flexibility in phasing because they were dark active but light feeding, and vice versa. Under DD, red sea bream showed free-running rhythms for locomotor activity and feeding. These results indicate that the type of phasing of locomotor activity did not necessarily decide the feeding phase; much of this is explained by the fact that red sea bream were demand-fed. Flexibility in phasing and a certain degree of independence between locomotor and feeding activities could be seen as an adaptative response of the highly adaptable circadian rhythms of fish.

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Mission Design and Analysis based on SEM Angle by Using Variable Coast During 3.5 Earth-Moon Phasing Loop Transfer (Variable Coast를 이용하는 3.5 지구-달 위상전이궤적에서 SEM 각도에 따른 임무설계 및 해석)

  • Choi, Su-Jin;Lee, Donghun;Lim, Seong-Bin;Choi, Suk-Won
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.46 no.1
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    • pp.68-77
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    • 2018
  • In order to analyze the overall characteristics of the lunar orbiter, the Variable Coast method, which can be launched everyday, is applied to the 3.5 phasing loop transfer trajectory. The mission scenario for the entire process from launching to entering the lunar orbit is set up and performed simulation by selecting the launch pad and launch vehicle. In particular, the SEM(Satellite-Earth-Moon) angle defined in Earth-Moon rotating frame is an important constraint to comprehensively evaluate the 3.5 phasing loop transfer trajectory. The simulation using SEM angle is analyzed from various viewpoints such as launch epoch, coast duration, perigee altitude and ${\Delta}V$ not only trans-lunar trajectory but lunar orbit insertions and the optimum SEM angle is suggested in this study. It is expected that this results will be helpful to evaluate the characteristics of the 3.5 phasing loop transfer trajectory according to the launch vehicle selection by comparison with Fixed Coast analysis results in the future.

Comparison of Capacities at an Intersection with Lagging or Leading Left Turn Green Phase (직진(直進)과 좌회전(左回轉) 신호순서(信號順序)에 따른 교차로(交叉路) 용량분석(容量分析)과 신호시간(信號時間) 연구(硏究))

  • Do, Cheol Ung
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.3 no.3
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    • pp.19-26
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    • 1983
  • Through traffic utilization of left turn lane constitutes an unique traffic operation at an intersection. Consequently, due to the provision as of current practice, conventional methods which estimate traffic volume and intersection capacity by lane would not be valid for design of signal timings. Through traffic utilization factor of left turn lane is affected by left turn volume and signal timings. The primary purpose of this study is to compare the results from leading left turn green phasing scheme with those from previously studied lagging left turn green phasing scheme in terms of utilization factor and intersection capacity by various left turn volume and signal timings, and thereby optimum signal timing to maximize the capacity at given left turn volume. Leading left turn green phasing increases capacity by 10~15 % as compared with that for current lagging left turn green phasing scheme. The range of optimum cycle length for left turn volume about 150 vph is 180~200 second. This cycle length range and left turn interval are longer than those for the lagging left turn green phasing scheme.

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Performance Analysis of the UPC/NPC Algorithm for Guaranteed QoS in ATM Networks

  • Kim, Yong-Jin;Kim, Jang-Kyung;Lee, Young-Hee;Park, Chee-Hang
    • ETRI Journal
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    • v.20 no.3
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    • pp.251-271
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    • 1998
  • It is well known that if usage parameter control/network parameter control (UPC/NPC) functions are used together with a cell loss priority control scheme in ATM networks, the measurement phasing problem can occur. This makes it difficult for a network provider to define and commit the cell loss ratio as a QoS parameter. To solve the problem, we propose a new UPC/NPC algorithm. By using the proposed UPC/NPC algorithm, we can define the cell loss ratios for CLP = 0 and CLP = 0+1 cell streams without the measurement phasing problem under any conditions. We analyzed the performance of the proposed UPC/NPC algorithm. Using a discrete time model for the UPC/NPC architecture with a discrete-time semi-Markov process (DSMP) input model, we obtained the cell discarding probabilities of CLP = 0 and CLP = 0+1 cells streams and showed that more CLP = 0 cells are accepted compared to what was proposed in ITU-T.

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Combustion Characteristics of a Small Diesel Engine Converted to Spark Ignition Operation and Fuelled with Natural Gas (디젤 기관을 개조한 소형 전기점화식 천연가스기관의 연소 특성 연구)

  • Park, S.;.Thomas, D. G.
    • Transactions of the Korean Society of Automotive Engineers
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    • v.4 no.6
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    • pp.65-77
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    • 1996
  • A small-sized industrial diesel engine was converted to a spark ignited engine and then adapted for fuelling with natural gas. After conversion work, general combustion characteristics of the gas engine(such as ignition delay, main and total combustion durations, and heat release characteristics) were studied as a functio of major engine operating variables such as air to fuel ratio, spark timing, and spark plug type. Some other studies on cyclic variation characteristics in IMEP, Pmax and (dp/dφ)max, and also optimum combustion phasing angle were performed.

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