共查询到10条相似文献，搜索用时 109 毫秒
1.
电磁波和弹性波的复反射函数无论从数学表达形式上,还是从物理意义上都有一定的相似性。通过对拟地震解释法中反射系数qn的求取,将频率测深曲线转换成vp－t0曲线及时间剖面,并对均匀介质及2层、3层、4层断面的理论模型和实例做了正反演计算。结果表明,频率测深拟地震解释法作为一种新的解释手段具有较好的应用前景。 相似文献
2.
V.V. Plotkin 《Russian Geology and Geophysics》2018,59(3):324-333
The paper presents the results of a joint inversion of magnetotelluric sounding (MTS) curves taken at several stations without preliminary selection and normalization and distorted by the presence of lateral electrical-conductivity inhomogeneities in the medium. In the calculations, we used synthetic MTS data for a three-dimensional model. Preparation and interpretation of data are carried out by the Trefftz method using a numerical model of the field and MTS curve distortions. To solve the inverse problem and optimize the subsurface model, we used a nonlinear least-squares method and an iterative process with calculation of the sensitivity matrix and its singular decomposition. The target functional is determined by the discrepancies between the model and synthetic experimental apparent-resistivity curves corresponding to the elements of the impedance tensors on the lateral diagonal. The reliability of the reconstructed subsurface model is characterized by the dispersion of the deviations of its parameters from the parameters of the known model used for the preparation of synthetic experimental data. The joint consideration of distorted apparent-resistivity curves at several stations increases the reliability of interpretation results. The obtained solution to the inverse problem is approximate and can be used as a starting model for more complex algorithms and programs. 相似文献
3.
巷道空间对矿井电测曲线影响的模型实验研究 总被引：6，自引：0，他引：6
在物理模型实验的基础上,以巷道顶、底板电测深法和矿井高密度电阻率法为例,对巷道影响规律进行了研究,确定了表征巷道空间对矿井电测结果影响的经验公式。 相似文献
4.
激发极化法测深曲线解释中的快速反演法 总被引：2，自引：0，他引：2
本文根据“直流电阻率测率深曲线解释中的直接反演法”一文,利用塞格尔的极化率模型,首先给出了在激发极化法测深曲线解释中的直接反演方法,在此基础上,又结合Ｏｌｄｅｎｂｕｒｇ,Ｚｏｈｄｙ等人的工作,使用对比迭代反演方法来提高反演精度,文章对几条理论测深曲线进行反演检验,结果表明效果很好。 相似文献
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J. P. Fernández Alvarez J. L. Fernández Martínez C. O. Menéndez Pérez 《Mathematical Geosciences》2008,40(4):375-408
DC resistivity inverse problems are ill-posed. For the Vertical Electrical Sounding method the acceptable solutions lie in
very narrow elongated-shape regions in the model space. To characterize this ensemble of solutions is a central question.
In a Bayesian framework this issue is solved adopting as solution the so-called model posterior probability distribution.
However, due to the nonlinearity of the problem, this distribution is not explicitly known, or it is difficult to calculate.
Therefore, algorithms that efficiently sample the model space according to it (importance sampling) are very desirable. The
main goal of this paper is to numerically explore the performance of binary genetic algorithms as posterior importance sampling
strategies. Their behavior will be firstly analyzed using 2D synthetic posterior test functions bearing the relevant properties
of the real geo-electrical inverse problem. The conclusions will be again checked through the histogram reconstruction of
parameters in a synthetic VES case, and eventually, in a real, higher dimensional, sea-water coastal intrusion problem, by
comparing the results with those obtained with a theoretically correct Metropolis-Hasting importance sampler (simulated annealing
without cooling). Percentile curves are introduced as an effective tool for risk assessment. We show that binary genetic algorithms
perform well under very general assumptions. When the roulette wheel is the selection method used, mutation is over 10%, and
the algorithm does not incorporate elitism. The results do not depend on the values of the remaining tuning parameters. Finally,
to improve the efficiency of the sampling strategy, we introduce a binary genetic algorithm with oriented search space. This
is done with the help of linearization of the forward operator and singular value decomposition around the maximum posterior
estimate. It is shown, also, that the logarithmic model parameterization is adequate for this task. 相似文献
7.
巷道层测深理论曲线数值模拟及资料解释方法 总被引：3，自引：4，他引：3
建立了层测深理论曲线正常规模拟的数学模型，结合三层和四层地电模型层测深视电阻及视电阻率理论曲线的正演计算，研究了层测深曲线特征和解释方法，同时介绍了煤矿井下层测深法的应用实例。 相似文献
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在这篇文章中，分析了一个具有井眼的非均匀介质中似稳电流场的边值问题。采用了三维有限元的直接解法求解三维似稳电流场；给出了微侧向测井仪器的电极表面电流分布、假几何因子以及８英寸井眼的泥饼校正曲线；求出了在具有倾斜地层条件下，微侧向测井仪器对界面的响应。数值结果与发表的文献非常吻合，从而证明了这种方法的正确性。因此，它为新的仪器研制和微侧向测井解释提供了可靠的数据和理论依据。 相似文献
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