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31.
本文运用双重Fourier级数分析了受横向均布载荷作用下两邻边铰支两邻边固支矩形板的非线性弯曲问题。利用该级数正交性,可以把非线性偏微分控制方程化为含级数系数的非线性代数方程组并通过迭代解出所有系数。最后给出了位移和应力的计算结果。 相似文献
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弹道跟踪系统的数据融合 总被引:3,自引:0,他引:3
本文应用近代时序分析方法、样条函数和非线性回归分析理论,研究了弹道参数、系统误差及测量随机误差统计特性参数的联合估计问题,给出了各类参数的高精度估计。理论分析和仿真计算表明:本文所建的模型准确,参数估计方法精度高,应用本文方法能明显提高弹道跟踪数据质量。 相似文献
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官晨 《华北航天工业学院学报》2011,(5):16-19
应用差分自回归滑动平均模型(ARIMA)模型对西藏拉萨地区1969年至2009年的年降水量资料进行建模分析。建立的模型通过了参数的显著性检验和模型的显著性检验。模型的实证分析表明在短期内模型具有较高的预测精度,ARIMA模型可以较好的应用于降水量的预测,对相关部门采取措施应对自然灾害提供了理论支持。 相似文献
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A. Hovhannisyan A. Chilingarian 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2011
Particle detectors of worldwide networks are continuously measuring various secondary particle fluxes incident on Earth surface. At the Aragats Space Environmental Center (ASEC), the data of 12 cosmic ray particle detectors with a total of ∼280 measuring channels (count rates of electrons, muons and neutrons channels) are sent each minute via wireless bridges to a MySQL database. These time series are used for the different tasks of off-line physical analysis and for online forewarning services. Usually long time series contain several types of errors (gaps due to failures of high or low voltage power supply, spurious spikes due to radio interferences, abrupt changes of mean values of several channels or/and slowly trends in mean values due to aging of electronics components, etc.). To avoid erroneous physical inference and false alarms of alerting systems we introduce offline and online filters to “purify” multiple time-series. In the presented paper we classify possible mistakes in time series and introduce median filtering algorithms for online and off-line “purification” of multiple time-series. 相似文献
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感应电能传输(CIPT)技术,是一种新型的电能传输方式,能实现无电气连接的电能传送.松耦合变压器的引入,使得耦合系数较常规变压器低,对系统损耗准确建模成为CIPT技术的关键问题.本文通过对CIPT各个元器件的功率损耗分析,研究各个功率模块损耗之间的耦合关系.以损耗关于原边线圈电流的泰勒展开式为基础,建立CIPT系统功率损耗模型及效率模型.为验证理论分析的正确性,设计制作了一个CIPT样机,通过对不同工况进行比较实验,证明了所建磁路模型、效率模型的正确性.提出的损耗分析方法能够用来指导CIPT系统的分析与设计. 相似文献
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Wei Wang Bin Zhao Qi Wang Shaomin Yang 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2012
The Crustal Movement Observation Network of China (CMONOC) is one of the major scientific infrastructures, mainly using Global Positioning System (GPS) measurements, to monitor crustal deformation in the Chinese mainland. In this paper, decade-long coordinate time series of 26 continuous GPS sites of CMONOC are analyzed for their noise content using maximum likelihood estimation (MLE). We study the noise properties of continuous GPS time series of CMONOC for the unfiltered, filtered solutions and also the common mode signals in terms of power law plus white noise model. In the spatial filtering, we remove for every time series a common mode error that was estimated from a modified stacking of position residuals from other sites within ∼1000 km of the selected site. We find that the common mode signal in our network has a combination of spatially correlated flicker noise and a common white noise with large spatial extent. We demonstrate that for the unfiltered solutions of CMONOC continuous GPS sites the main colored noise is a flicker process, with a mean spectral index of ∼1. For the filtered solutions, the main colored noise is a general power law process, indicating that a major number of the filtered regional solutions have a combination of noise sources or local effects. The velocity uncertainties from CMONOC continuous GPS coordinate time series may be underestimated by factors of 8–16 if a pure white noise model is assumed. In addition, using a white plus flicker noise model, the median values of velocity errors for the unfiltered solutions are 0.16 (north), 0.17 (east) and 0.58 (vertical) mm/yr, and the median values for the filtered solutions are 0.09 (north), 0.10 (east) and 0.40 (vertical) mm/yr. 相似文献
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P. Willis J.C. Ries N.P. Zelensky L. Soudarin H. Fagard E.C. Pavlis F.G. Lemoine 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2009
For Precise Orbit Determination of altimetry missions, we have computed a data set of DORIS station coordinates defined for specific time intervals called DPOD2005. This terrestrial reference set is an extension of ITRF2005. However, it includes all new DORIS stations and is more reliable, as we disregard stations with large velocity formal errors as they could contaminate POD computations in the near future. About 1/4 of the station coordinates need to be defined as they do not appear in the original ITRF2005 realization. These results were verified with available DORIS and GPS results, as the integrity of DPOD2005 is almost as critical as its accuracy. Besides station coordinates and velocities, we also provide additional information such as periods for which DORIS data should be disregarded for specific DORIS stations, and epochs of coordinate and velocity discontinuities (related to either geophysical events, equipment problem or human intervention). The DPOD model was tested for orbit determination for TOPEX/Poseidon (T/P), Jason-1 and Jason-2. Test results show DPOD2005 offers improvement over the original ITRF2005, improvement that rapidly and significantly increases after 2005. Improvement is also significant for the early T/P cycles indicating improved station velocities in the DPOD2005 model and a more complete station set. Following 2005 the radial accuracy and centering of the ITRF2005-original orbits rapidly degrades due to station loss. 相似文献