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陈伯舫 《地震地磁观测与研究》1994,15(5):18-21
本文分析了拉萨台长周期成分的感应尺度Ｃ值。周期范围从０．３－６７ｄ，超过两个量级。用Ｍｏｎｔｅ－Ｃａｒｌｏ法对所得的Ｃｒｅ（Ｔ）和Ｃｉｍ（Ｔ）结果进行反演计算，反演结果给出了深部电导率结构可能的多解范围和最佳拟合的电性模型。所谓最佳拟合是指目标函数值最小的一种拟合。 相似文献
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讨论了利用磷灰石裂变径迹资料反演热演化史的综合分析法．这一方法综合了Ｓｉｍｐｌｅｘ和ＭｏｎｔｅＣａｒｌｏ方法的特点．初值选择采用ＭｏｎｔｅＣａｒｌｏＢｏｘ选择法，而反演迭代则应用Ｓｉｍｐｌｅｘ方法．由于应用了ＭｏｎｔｅＣａｒｌｏＢｏｘ，从而保证了初值在某一限定区域内的随机性选择，避免了目标函数陷入局部极值区而使反演失真的情况．在地质条件约束下，它可以成功地获得目标函数极小值或极小值邻域内的极值以及它们对应的热史的解．应用理论模型，验证了本方法的有效性和稳定性．在初值偏离真值较远（２０－５０℃偏差）的情况下，本方法也可以获得满意的解．以中国东部某凹陷井中实测磷灰石裂变径迹长度分布和退火年龄资料为实例，进行了热史的反演计算模拟，结果清楚地解释了样品所处地区的构造和沉降史． 相似文献
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本文研究了地基土－桩－核岛辅助厂房结构相互作用体系在地震激励时的“平－扭”耦联动力响应，在分析中分别采用Ｍ．Ｎｏｖａｋ的近似理论，Ｍ．Ｎｏｖａｋ常数法，Ｍ法，常数法计算了桩基础的阻抗函数，并考虑了在同一基础上的安全壳和另一辅助厂房对所研究的辅助厂房动力响应的影响。 相似文献
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倾角时差校正（ＤＭＯ）方法对于复杂地质构造条件下的纵波反射波（Ｐ－Ｐ）的多次覆盖地震数据的叠加具有显著的提高信噪比的效果．对于转换反射波（Ｐ－ＳＶ）来说，进行倾角时差校正（ＤＭＯ）处理就更需要．本文首先对Ｐ－ＳＶ波的倾角时差校正（ＤＭＯ）的几何原理进行了分析，然后重点研究用波动方程进行ＤＭＯ的方法，即Ｐ－ＳＶ转换反射波的叠前部分偏移的波动方程法．这种方法也适用于Ｐ－Ｐ反射波的叠前部分偏移处理．研究结果表明，波动方程ＤＭＯ方法在振幅保真方面比几何原理的ＤＭＯ方法有显著改善． 相似文献
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选用十个随时间趋势性变化的函数作为零漂估计函数项，选用一系列不同周期的正、余弦函数作为周期变化的函数项，建立倾斜仪观测值中所含函数项的数学模型，给出了对上述两类函数按统一标准计算及挑选的方法。对漳州地震台ＳＱ－７０Ｂ倾斜仪资料的计算结果显示这一数学模型基本符合实际；周期等于５０天的振幅，与台湾Ｍｓ＞５．０级地震和福建省内ＭＬ≥４．０级地震对应较好。 相似文献
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云南是一个地震多发区。１６５２年至１９９４年间云南地区共发生６１３次破坏性地震，其中５．０—５．９级地震５５３次，６．０—６．９级地震４９次，７．０—７．９级地震１２次，８级地震１次。云南的破坏性地震除了直接造成人员伤亡和建（构）筑物破坏外，还在震区形成包括滚石、崩塌、滑坡、泥石流、地面沉陷和喷砂冒水等地面破坏现象，这些地面破坏造成人员伤亡，毁坏建筑物和农田，形成云南破坏性地震灾害特点。云南地区破坏性地震的人员伤亡和地面破坏主要集中发生在滇中、滇西北和滇西南地区。根据统计分析，云南地区破坏性地震的平均人员伤亡人数（Ｎ）与地震震级（Ｍ）的关系为：ｌｇＮ＝１．５Ｍ－７．４。人员伤亡数（Ｎ）与震中距Ｄ（ｋｍ）的关系为：ｌｇＮ＝０．８－０．０２７Ｄ（６．０—６．９级地震）和ｌｇＮ＝３．２－０．０５Ｄ（７级以上地震）。出现地面破坏现象的最大震中距离（Ｄｍａｘ）和震级的关系为：Ｄｍａｘ（ｋｍ）＝５２Ｍ－２９８（地表裂缝）；Ｄｍａｘ（ｋｍ）＝１８Ｍ－９３（崩塌滑坡）；Ｄｍａｘ（ｋｍ）＝５０Ｍ－２８１（滚石）。 相似文献
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为了解决有限地震断层破裂过程研究中的正演和反演问题，本文提出：（1）用广义反射、透射系数矩阵和广义射线理论计算上地幔及远场范围体波理论地震图的混合方法．同时采用格林函数的一种新的组合方式，可节约1／3计算机内存．（2）采用基于模拟退火的热浴算法进行全局搜索反演，不仅提高了在计算过程中新模型被接收的可能性，而且使得在时间域内目标函数的计算速度提高了近二个数量级．对1994年台湾海峡地震震源破裂过程的研究结果表明，这次地震的破裂过程相对比较简单．在前4．0s内地震断层的破裂相当剧烈，错动距离的平均值随着破裂时间增加而迅速减少．开始时破裂速度较高，前4．0s的平均值为3．1km／s，之后逐渐降至2．2km／s．错动方向随破裂的变化不大． 相似文献
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根据Ｂｒｕｎｅ（１９７０）提出的震源位错模式，用发生在滇西地震实验场区鹤庆ＭＳ＝５．３中强地震的地震数字化监测资料，计算了Ｓ波谱，测定了鹤庆地震序列的震源参数．在此基础上研究了地面运动峰值速度参数（ｒ．ｖ）对地震应力降Δσ的依赖性．由地震标定关系给出（ｒ．ｖ）∝Δσ２／３，导出了用峰值速度参数求地震应力降的３个关系：ｌｇ（ｒ．ｖ）＝ｄ１＋（１／３）ｌｇＭ０＋（２／３）ｌｇΔσ；ｌｇ（ｒ．ｖ）＝ｄ２＋（１／３）ＭＬ＋（２／３）ｌｇΔσ；ｌｇΔσ＝－１．０＋１．５ｌｇ（ｒ．ｖ）．假定对大小地震的平均应力降取３．０ＭＰａ，由鹤庆地震序列的观测资料定出常数ｄ１＝－３．８８和ｄ２＝－０．３８．序列震源参数测定结果给出，地震矩为１０１１～１０１５Ｎ·ｍ，破裂半径ａ＝２００～６００ｍ．根据峰值速度测定的应力降Δσ＝０．１～１０ＭＰａ，平均为３．７ＭＰａ．用这些标度关系求出的应力降结果与Ｂｒｕｎｅ模式求应力降的结果比较一致．本文的研究结果还表明，地面运动峰值速度参数对地震应力降的依赖性比对地震矩的依赖性更强． 相似文献
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Comparing the performances of four stochastic optimisation methods using analytic objective functions, 1D elastic full‐waveform inversion,and residual static computation 
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下载免费PDF全文 Angelo Sajeva Mattia Aleardi Bruno Galuzzi Eusebio Stucchi Emmanuel Spadavecchia Alfredo Mazzotti 《Geophysical Prospecting》2017,65(Z1):322-346
We compare the performances of four stochastic optimisation methods using four analytic objective functions and two highly non‐linear geophysical optimisation problems: one‐dimensional elastic full‐waveform inversion and residual static computation. The four methods we consider, namely, adaptive simulated annealing, genetic algorithm, neighbourhood algorithm, and particle swarm optimisation, are frequently employed for solving geophysical inverse problems. Because geophysical optimisations typically involve many unknown model parameters, we are particularly interested in comparing the performances of these stochastic methods as the number of unknown parameters increases. The four analytic functions we choose simulate common types of objective functions encountered in solving geophysical optimisations: a convex function, two multi‐minima functions that differ in the distribution of minima, and a nearly flat function. Similar to the analytic tests, the two seismic optimisation problems we analyse are characterised by very different objective functions. The first problem is a one‐dimensional elastic full‐waveform inversion, which is strongly ill‐conditioned and exhibits a nearly flat objective function, with a valley of minima extended along the density direction. The second problem is the residual static computation, which is characterised by a multi‐minima objective function produced by the so‐called cycle‐skipping phenomenon. According to the tests on the analytic functions and on the seismic data, genetic algorithm generally displays the best scaling with the number of parameters. It encounters problems only in the case of irregular distribution of minima, that is, when the global minimum is at the border of the search space and a number of important local minima are distant from the global minimum. The adaptive simulated annealing method is often the best‐performing method for low‐dimensional model spaces, but its performance worsens as the number of unknowns increases. The particle swarm optimisation is effective in finding the global minimum in the case of low‐dimensional model spaces with few local minima or in the case of a narrow flat valley. Finally, the neighbourhood algorithm method is competitive with the other methods only for low‐dimensional model spaces; its performance sensibly worsens in the case of multi‐minima objective functions. 相似文献
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Modified genetic algorithm with simulated annealing applied to optimal load dispatch of the Three Gorges Hydropower Plant in China 总被引：1，自引：0，他引：1
A method is presented for optimal load dispatch in large-scale hydropower plants using a genetic algorithm integrated with simulated annealing. The genetic algorithm overcomes dependence on an initial value and provides parallel processing and fast convergence, whereas simulated annealing prevents prematurity and retrieving of the local instead of the global optimum. Thus, the integrated genetic-simulated annealing algorithm improves efficiency and robustness to obtain solutions close to the global optimum. We evaluated the proposed algorithm to determine the optimal load dispatch of 32 units of the Three Gorges Hydropower Plant in China. Test results show that the minimum water consumption obtained using the proposed algorithm is similar to the optimum obtained from a previously proposed “improved” genetic algorithm when the total load of the plant is relatively high. However, for reduced load, the proposed algorithm clearly outperforms the “improved” genetic algorithm. 相似文献
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实验室声发射三维定位软件 总被引：5，自引：2，他引：5
简要介绍了地震动力学实验室新一代声发射定位软件的主要功能、定位算法的实现方案以及定位效果的评测结果。新软件配有多种通用数据库接口,具有与设备无关的处理能力。它除了可以进行三维定位之外,还可以进行面定位与线定位。定位时,可以给定样品的波速,也可以把波速当未知数求解。定位算法的主要改进有两个方面:1)以稳健的走时绝对偏差最小作为定位目标函数;2)方程组求解优化过程采用了模拟退火法直接搜索目标函数的全局最小值。新软件显著提高了定位的精度,同时提供了一个方便快捷的数据处理平台 相似文献
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Si-Yu Li Shu-Ming Wang Peng-Fei Wang Xiao-Lu Su Xin-Song Zhang Zhi-Hui Dong 《Acta Geophysica》2018,66(4):607-621
The grey wolf optimizer (GWO) is a novel bionics algorithm inspired by the social rank and prey-seeking behaviors of grey wolves. The GWO algorithm is easy to implement because of its basic concept, simple formula, and small number of parameters. This paper develops a GWO algorithm with a nonlinear convergence factor and an adaptive location updating strategy and applies this improved grey wolf optimizer (improved grey wolf optimizer, IGWO) algorithm to geophysical inversion problems using magnetotelluric (MT), DC resistivity and induced polarization (IP) methods. Numerical tests in MATLAB 2010b for the forward modeling data and the observed data show that the IGWO algorithm can find the global minimum and rarely sinks to the local minima. For further study, inverted results using the IGWO are contrasted with particle swarm optimization (PSO) and the simulated annealing (SA) algorithm. The outcomes of the comparison reveal that the IGWO and PSO similarly perform better in counterpoising exploration and exploitation with a given number of iterations than the SA. 相似文献
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针对地震静校正存在的非线性和多参数性等问题，本文提出了一种全局优化的剩余静校正方法.在模型更新规则上，把模拟退火方法和均匀优化设计方法结合在一起，使模型的更新更为合理，从而加快了搜寻全局最优解的速度.同时提出了模型的不同分量的温度参数和退火过程的选取方式，把温度参数的选取与地震剖面的能量联系起来，使温度参数的选取具有自适应的特点.该方法克服了常规模拟退火方法所具有的寻优空间不均匀以及退火参数需通过多次试验选取的缺陷.通过实际地震资料的计算证明，本文提出的方法对地震静校正问题合理而有效. 相似文献
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Adaptive hybrid global inversion algorithm 总被引：2，自引：0，他引：2
Most geophysical inversions can be regarded as multiparameter, nonlinear, and multiminimum discontinuous optimization problems.
An adaptive hybrid global inversion algorithm based on simulated annealing, downhill simplex method, uniform design, and adaptive
annealing rule is formulated. Numeral test and model computation show that this algorithm has very fast speed and high efficiency
in searching for global minimum.
Project sponsored by the National Natural Science Foundation of China (Grant No. 49474232) and Special Foundation under the
auspices of president of Chinese Academy of Sciences. 相似文献
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Linearized residual statics estimation will often fail when large static corrections are needed. Cycle skipping may easily occur and the consequence may be that the solution is trapped in a local maximum of the stack-power function. In order to find the global solution, Monte Carlo optimization in terms of simulated annealing has been applied in the stack-power maximization technique. However, a major problem when using simulated annealing is to determine a critical parameter known as the temperature. An efficient solution to this difficulty was provided by Nulton and Salamon (1988) and Andresen et al. (1988), who used statistical information about the problem, acquired during the optimization itself, to compute near optimal annealing schedules. Although theoretically solved, the problem of finding the Nulton–Salamon temperature schedule often referred to as the schedule at constant thermodynamic speed, may itself be computationally heavy. Many extra iterations are needed to establish the schedule. For an important geophysical inverse problem, the residual statics problem of reflection seismology, we suggest a strategy to avoid the many extra iterations. Based on an analysis of a few residual statics problems we compute approximations to Nulton–Salamon schedules for almost arbitrary residual statics problems. The performance of the approximated schedules is evaluated on synthetic and real data. 相似文献