共查询到17条相似文献，搜索用时 62 毫秒
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无线传感器网络中基于时钟漂移补偿的时间同步技术 总被引：4，自引：0，他引：4
在分析和总结现有时间同步算法的特点及其存在问题的基础上,提出了一种在无线传感器网络的时间同步协议（TPSN）中同时考虑节点时钟偏移和频率漂移率的改进算法。该算法利用连续两次同步过程中所记录的时间信息来估算节点时钟的偏移和频率漂移率,并进行补偿。同传统算法相比,此算法通讯成本较低、精度较高。最后通过数学分析和仿真的方法对所提出的改进算法进行了验证。 相似文献
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胡锦伦 《中国科学院上海天文台年刊》1989,(10):255-263
本介绍了1985年国际搬钟时间同步实验和1987年国内搬钟时间同步实验中使用双混频时差（DMTD）测量技术的结果。实验结果表明：DMTD测量技术在搬钟时间同步实验中，对于确定钟速和同步精度以及严密监视钟的相位、频率跳变等方面是很有用的。它与秒脉冲（1PPS）时差测量技术可同时使用和相互补充。 相似文献
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共视法和综合法的GPS时间同步精度比较 总被引：1，自引：0，他引：1
胡锦伦 《中国科学院上海天文台年刊》2000,12(21):140-143
对共视法和综合法的GPS时间比对对得到的两地协调世界的时间同步精度进行了比较,两种方法各有特点,都有实用价值,严格共视的GPS时间同步精度为5－10ns,不严格共视的GPS的时间同步精度为10－20ns,综合的GPS时间同步精度为6－12ns. 相似文献
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The problem of clock synchronization: A relativistic approach 总被引：2，自引：0，他引：2
Sergei A Klioner 《Celestial Mechanics and Dynamical Astronomy》1992,53(1):81-109
The problem of synchronization of the Earth-based clocks has been discussed in the framework of General Relativity Theory. The synchronization is considered as the transformation of the observers' proper time scales to the coordinate time scale of local inertial geocentric reference system, which is single for all the observers. The formulas for the relativistic corrections occurring in some methods of Earth-based clock synchronization (transported clock, duplex communication via geostationary satellite and meteor-burst link, LASSO experiments) have been derived enabling one to attain the accuracy of 0.1 ns. 相似文献
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一种双向测距与时间同步系统的设计与分析 总被引：1，自引：0，他引：1
在研究双向单程伪距测量原理的基础上,设计了双向测距与时间同步（DRTS）终端系统总体构架,阐述了在系统中使用的技术,并搭建了基于DSP＋FPGA的双向测距与时间同步系统软硬件平台。实验结果表明,此系统的码速率为5MHz、中心频率为15MI-Iz时,测距和时间同步的分辨率可达0．15cm和5ps（@1S）,采用不同频率源时测距和时间同步的精度分别为1．038m和3．46ns,采用相同频率源时分别为0．28cm和9．43ps（参考频率稳定度1×10^-10／d量级）。与国外同类产品相比具有测量精度优势,但考虑通用性,此系统的硬件仍需进一步优化,软件上需要做到码速率可调。 相似文献
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Osamu Kaburaki 《Astrophysics and Space Science》1986,119(1):85-88
A new mechanism is proposed for the explanation of synchronous rotations in AM Herculis-type binaries. In contrast to the resistive mechanism of Josset al. (1979), our model predicts that an asynchronous rotation, if it is present, damps exponentially and the damping time is inversely proportional to the electrical conductivity. It is shown by using the parameters which fit for AM Herculis that a typical damping time is very short compared with the lifetime of the system.Paper presented at the I.A.U. Third Asian-Pacific Regional Meeting, held in Kyoto, Japan, between 30 September–6 October, 1984. 相似文献
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M. Takeuti 《Astrophysics and Space Science》1985,109(1):99-109
The coupled self-exciting oscillator model is investigated in the non-resonant case and applied to classical cepheids. The modal selection in these models is explained as the result of the synchronization caused by the mutual interaction between different modes. By using linear adiabatic coupling coefficients, it is shown that the fundamental mode suppresses the first overtone mode marginally in short-period classical cepheids. The double periodicity of several cepheids is expected as the result of a small change of physical state in the outer envelopes of these stars. 相似文献
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Simple models of nonlinear stellar pulsation, whose temporal behavior may reproduce some of the observed features of different classes of variable stars, have been studied. The temporal behavior of dynamical variables of these models exhibits a cascade of period doubling chaos, depending on the specific values of the various control parameters. A multifractal detrended fluctuation analysis (MFDFA) method is further used to identify the scaling behavior of such synthetic time series. The MFDFA of the considered time series, for various models of nonlinear stellar pulsation, shows that the observed multifractal nature is due to long-range correlations. The pulsating star with increased nonadiabaticity and the star with increased convective luminosity, as represented by the simulated data, is shown to possess a strange attractor with noninteger correlation dimension that lies between 2–3. Also the problem of synchronization in coupled nonlinear pulsation models has been investigated using permutation entropy—a complexity measure of the system. The computed order parameter, Γ, representing the correlation of computed permutation entropy for different segments of the simulated time series of displacement of two nonidentical oscillators, has been further used to find the critical coupling parameter for general synchronization of the oscillators. 相似文献