共查询到20条相似文献，搜索用时 93 毫秒
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《测绘与空间地理信息》2020,(6)
小波分析和奇异谱分析都可以作为处理含有噪声数据的方法,这两种去噪方式都可以消除数据中的噪声。基于两种数据处理方法,RBF神经网络预测隧道地表沉降数据的组合预测比单个模型的预测精度高,可获得更好的预测效果,为隧道监测安全提供可靠的参考。 相似文献
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伍锡锈 《测绘与空间地理信息》2018,(7):212-214
利用时间序列分析方法中的二次移动平均法提取出沉降监测序列中的趋势项,并在此基础上建立固定维数的动态GM(1,1)灰色模型进行沉降预测,同时利用Kalman滤波方法进行沉降预测,结合实际算例结果表明,这两种模型均能够较好地进行预测,证明了这两种预测模型均具有一定的可行性和有效性,并对两种预测模型在沉降监测预报中的应用进行了比较和分析。 相似文献
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在一般滑坡区域危险性预测方法的基础上,考虑动态预测,添加了降雨、蓄水水位变化、植被三种动态因素对于滑坡的作用,并以三峡库区中的重庆市涪陵区为例将动态预测方法加以实现。 相似文献
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灰色预测理论在建筑物沉降中的应用研究 总被引：1，自引：0，他引：1
简要介绍灰色预测理论,并结合GM(1,1)模型介绍灰色预测在变形监测中的理论方法。以吉林市世纪广场北侧挡水墙为例,分析GM(1,1)模型在变形监测中的精度和可行性,以及特殊情况。 相似文献
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An Assessment of the Accuracy of Triangulated Irregular Networks (TINs) and Lattices in ARC/INFO 总被引：2，自引：0，他引：2
This paper evaluates the accuracy of triangulated irregular networks (TINs) and lattices in ARC/INFO. The results of an empirical comparison of the two models over two selected topographic sites are presented. Both vector and raster data were used to build the models. Three pairs of models were constructed based on 1,600, 4,000, and 9,000 sample points for the study area of the State Botanical Garden of Athens, Georgia, and 400, 800, and 1,600 sample points for the study area of Lake Lucerne of Wisconsin. The two models were assessed based on the same number of input sample points. Overall, TINs performed better than lattices. The quality of lattices decreased more dramatically than that of TINs when the number of sample points used for the construction of the models decreased. With an increase in the number of sample points used, the difference in performance between the two models decreased. The results of the evaluation directly depend on the comparison criteria and modeling algorithms. The evaluation is slightly sensitive to test indices used and the distribution of test points. The spatial pattern of residuals on spot heights was quite different from that on randomly selected test points. Users should choose models carefully based on the purpose of their application, the accuracy required, and the computer resources that are available. 相似文献
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针对欧洲中程天气预报中心实时大气数据中由于水平及垂直分辨率变化所引起的大气压跳跃,利用再分析大气数据（ERA-Interim）及去平滑球谐分析方法计算重力恢复与气候实验卫星（gravity recovery and climate experiment,GRACE）大气去混频模型,从谱域、空域角度及利用主成分分析方法比较其与标准大气与海洋去混频模型的差距,并采用星间距离变率残差作为标准衡量两种模型的优劣。结果表明:两种模型之间精度相近,用于计算时变重力场模型时其影响可忽略,但在用于计算下一代卫星重力场模型时,需考虑其影响。 相似文献
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介绍了用差分算子和时间序列分析法建立数字化过程随机误差估计模型中的粗差探测方法和抗差估计方案。 相似文献
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Abstract It has been well established that neural networks provide a reasonable and powerful alternative to conventional classifiers. During the past few years there has been a large and energetic upswing in research efforts aimed at synthesizing fuzzy logic with neural networks. This combination of fuzzy logic and neural networks seems natural because two approaches generally attack the design of “intelligent” systems from quite different angles. Neural networks provide algorithms for learning, classification, and optimization whereas fuzzy logic deals with issues such as reasoning on a higher (semantic or linguistic) level. Consequently the two technologies complement each other. In this paper we propose two novel fuzzy‐neural network models for supervised learning. The first model consists of three layers, and the second model consists of four layers. In both models, the first two layers implement fuzzy membership functions and the remaining layers implement the inference engine. Both models use the gradient decent technique for learning. As an illustration, we have analyzed two Thematic mapper images using these models. Results are presented in the paper. 相似文献
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All conventional Kalman filtering methods depend to a great extent on dynamic models for describing the motion state of vehicle.
However, low-cost GPS navigation systems do not provide velocity and acceleration measurements to construct dynamic models.
Therefore, it is rather difficult to establish reasonable dynamic models. A windowing-recursive approach (WRA) which employs
previous positions to predict the current position is proposed, and the transition matrix is modeled for transforming the
previous positions to the current one. Two typical transition matrices are constructed by numerical polynomial fitting and
extrapolation. A real vehicular GPS experiment is carried out to demonstrate the WRA performances in two relative positioning
scenarios. The data are processed by the least squares approach and by WRA using the two developed transition matrices. The
results show that the WRA performed excellently in a high sampling rate data. In case of a lower sampling rate, higher-order
polynomial fitting and extrapolation models work better than lower-order models for a given window. In addition, the extrapolation
models can alleviate the computation burdens significantly relative to the polynomial fitting models. 相似文献
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贾明海 《武汉大学学报(信息科学版)》1989,(2)
根据随机介质理论可以导出开采引起的地表动态变形表达式。本文利用该式建立了适合动态数据处理的两种滤波模型,并把变形表达式中各参数扩充为滤波模型中的状态向量同时进行估计。两种模型的动态预报精度均高于传统方法,其中自适应模型更能明显改善预报精度。 相似文献
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Landslides susceptibility maps were constructed in the Pyeong-Chang area, Korea, using the Random Forest and Boosted Tree models. Landslide locations were randomly selected in a 50/50 ratio for training and validation of the models. Seventeen landslide-related factors were extracted and constructed in a spatial database. The relationships between the observed landslide locations and these factors were identified by using the two models. The models were used to generate a landslide susceptibility map and the importance of the factors was calculated. Finally, the landslide susceptibility maps were validated. Finally, landslide susceptibility maps were generated. For the Random Forest model, the validation accuracy in regression and classification algorithms showed 79.34 and 79.18%, respectively, and for the Boosted Tree model, these were 84.87 and 85.98%, respectively. The two models showed satisfactory accuracies, and the Boosted Tree model showed better results than the Random Forest model. 相似文献
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地铁变形监测中曲线拟合与自回归模型的综合应用 总被引：3，自引：0，他引：3
曲线拟合与自回归是变形监测数据分析的常用方法。本文首先给出曲线拟合和自回归模型的模型形式以及模型正确性的检验方法,然后结合广州某地铁的部分实际监测资料,综合使用两种模型进行变形曲线的拟合与分析,结果表明:该综合模型对变形数据的处理有着显著的优越性。 相似文献