A hybrid inversion method of damped least squares with simulated annealing used for Rayleigh wave dispersion curve inversion

Surface wave methods are becoming increasingly popular in many geotechnical applications and in earthquake seismology due to their noninvasive characteristics.Inverse surface wave dispersion curves are a crucial step in most surface wave methods.Many inversion methods have been applied to surface wave dispersion curve inversion,including linearized inversion and nonlinearized inversion methods.In this study,a hybrid inversion method of Damped Least Squares(DLS) with Very Fast Simulated Annealing(VFSA) is developed for multi-mode Rayleigh wave dispersion curve inversion.Both synthetic and in situ fi eld data were used to verify the validity of the proposed method.The results show that the proposed method is superior to the conventional VFSA method in aiming at global minimum,especially when parameter searching space is adjacent to real values of the parameters.The advantage of the new method is that it retains both the merits of VFSA for global search and DLS for local search.At high temperatures,the global search dominates the runs,while at a low temperatures,the local search dominates the runs.Thus,at low temperatures,the proposed method can almost directly approach the actual model.

The Improved Simulated Annealing Algorithm and Application in the Surface Wave Dispersion Inversion

The velocity distribution of layers from surface wave dispersion curve is a severely nonlinear program. Base on the Metropolis rule,we improved the simulated annealing algorithm to simultaneously inverse the velocities and thicknesses using the dispersion data and identified the Moho and the bottom of lithosphere. The application to the numerical examples with 5% noise shows the velocity RMS is 1. 56% between the non-linear results and the original models when the condition of selecting method for temperature parameters and initial temperature are satisfied. Using the pure dispersions of Rayleigh wave,the nonlinear inversion has been carried out for S-wave velocities and thicknesses of the vertical profile crossing the Indian Plate,the Qinghai-Tibetan Plateau,and the Tarim Basin. It indicated that the crustal thickness is about 70 km in the Qiangtang block,while in the hinterland of the Qinghai-Tibetan Plateau the lithosphere is relatively thin(~ 130 km)from the velocity values and their offsets.

Revenue Optimization of Pipelines Construction and Operation Management Based on Quantum Genetic Algorithm and Simulated Annealing Algorithm

For the optimization of pipelines, most researchers are mainly concerned with designing the most reasonable section to meet the requirements of strength and stiffness, and at the same time reduce the cost as much as possible. It is undeniable that they do achieve this goal by using the lowest cost in design phase to achieve maximum benefits. However, for pipelines, the cost and incomes of operation management are far greater than those in design phase. Therefore, the novelty of this paper is to propose an optimization model that considers the costs and incomes of the construction and operation phases, and combines them into one model. By comparing three optimization algorithms (genetic algorithm, quantum genetic algorithm and simulated annealing algorithm), the same optimization problem is solved. Then the most suitable algorithm is selected and the optimal solution is obtained, which provides reference for construction and operation management during the whole life cycle of pipelines.

Near-surface velocity inversion from Rayleigh wave dispersion curves based on a differential evolution simulated annealing algorithm

The utilization of urban underground space in a smart city requires an accurate understanding of the underground structure.As an effective technique,Rayleigh wave exploration can accurately obtain information on the subsurface.In particular,Rayleigh wave dispersion curves can be used to determine the near-surface shear-wave velocity structure.This is a typical multiparameter,high-dimensional nonlinear inverse problem because the velocities and thickness of each layer must be inverted simultaneously.Nonlinear methods such as simulated annealing(SA)are commonly used to solve this inverse problem.However,SA controls the iterative process though temperature rather than the error,and the search direction is random;hence,SA always falls into a local optimum when the temperature setting is inaccurate.Specifically,for the inversion of Rayleigh wave dispersion curves,the inversion accuracy will decrease with an increasing number of layers due to the greater number of inversion parameters and large dimension.To solve the above problems,we convert the multiparameter,highdimensional inverse problem into multiple low-dimensional optimizations to improve the algorithm accuracy by incorporating the principle of block coordinate descent(BCD)into SA.Then,we convert the temperature control conditions in the original SA method into error control conditions.At the same time,we introduce the differential evolution(DE)method to ensure that the iterative error steadily decreases by correcting the iterative error direction in each iteration.Finally,the inversion stability is improved,and the proposed inversion method,the block coordinate descent differential evolution simulated annealing(BCDESA)algorithm,is implemented.The performance of BCDESA is validated by using both synthetic data and field data from western China.The results show that the BCDESA algorithm has stronger global optimization capabilities than SA,and the inversion results have higher stability and accuracy.In addition,synthetic data analysis also shows that BCDESA can avoid the problems of the conventional SA method,which assumes the S-wave velocity structure in advance.The robustness and adaptability of the algorithm are improved,and more accurate shear-wave velocity and thickness information can be extracted from Rayleigh wave dispersion curves.

Quantum control based on three forms of Lyapunov functions

This paper introduces the quantum control of Lyapunov functions based on the state distance, the mean of imaginary quantities and state errors.In this paper, the specific control laws under the three forms are given.Stability is analyzed by the La Salle invariance principle and the numerical simulation is carried out in a 2D test system.The calculation process for the Lyapunov function is based on a combination of the average of virtual mechanical quantities, the particle swarm algorithm and a simulated annealing algorithm.Finally, a unified form of the control laws under the three forms is given.

Prestack seismic stochastic inversion based on statistical characteristic parameters

In the conventional stochastic inversion method,the spatial structure information of underground strata is usually characterized by variograms.However,effectively characterizing the heterogeneity of complex strata is difficult.In this paper,multiple parameters are used to fully explore the underground formation information in the known seismic reflection and well log data.The spatial structure characteristics of complex underground reservoirs are described more comprehensively using multiple statistical characteristic parameters.We propose a prestack seismic stochastic inversion method based on prior information on statistical characteristic parameters.According to the random medium theory,this method obtains several statistical characteristic parameters from known seismic and logging data,constructs a prior information model that meets the spatial structure characteristics of the underground strata,and integrates multiparameter constraints into the likelihood function to construct the objective function.The very fast quantum annealing algorithm is used to optimize and update the objective function to obtain the fi nal inversion result.The model test shows that compared with the traditional prior information model construction method,the prior information model based on multiple parameters in this paper contains more detailed stratigraphic information,which can better describe complex underground reservoirs.A real data analysis shows that the stochastic inversion method proposed in this paper can effectively predict the geophysical characteristics of complex underground reservoirs and has a high resolution.

Performance comparison of several optimization algorithms in matched field inversion

Optimization efficiencies and mechanisms of simulated annealing, genetic algorithm, differential evolution and downhill simplex differential evolution are compared and analyzed. Simulated annealing and genetic algorithm use a directed random process to search the parameter space for an optimal solution. They include the ability to avoid local minima, but as no gradient information is used, searches may be relatively inefficient. Differential evolution uses information from a distance and azimuth between individuals of a population to search the parameter space, the initial search is effective, but the search speed decreases quickly because differential information between the individuals of population vanishes. Local downhill simplex and global differential evolution methods are developed separately, and combined to produce a hybrid downhill simplex differential evolution algorithm. The hybrid algorithm is sensitive to gradients of the object function and search of the parameter space is effective. These algorithms are applied to the matched field inversion with synthetic data. Optimal values of the parameters, the final values of object function and inversion time is presented and compared.

基于模拟退火量子遗传算法的焊接机器人轨迹规划

针对焊接机器人在焊接过程中经常出现的轨迹规划问题,以六自由度机械臂PUMA 560为研究对象,采用笛卡尔空间规划轨迹,并利用混合算法,以关节惯性力矩变化量最小为优化目标,对不同末端位置的各个关节惯性力矩进行优化,从而消除了机械臂焊接过程中的运行不稳定、关节运动不平稳等问题。克服了模拟退火算法收敛速度慢及量子遗传算法局部寻优能力差等问题,成功规划出机械臂关节惯性力矩最优轨迹。MATLAB仿真结果表明,模拟退火量子遗传算法收敛时间相比传统遗传算法缩短30.56%,并且优化了关节惯性力矩,验证了该算法的可行性,可为后续研究奠定基础。

基于DTS的注水井吸水剖面解释方法

针对注水井分层注水量诊断技术难题,提出基于分布式光纤温度传感(Distributed Temperature Sensing,DTS)的注水井吸水剖面解释方法。建立考虑微量热效应的注水井温度剖面预测模型,模拟分析注水量、注水时间、储层导热系数等7个因素对温度剖面的影响规律。通过正交试验模拟分析,确定不同因素对注水井温度剖面的影响程度从强到弱分别为注入水温度、注水时间、注水量、井筒半径、储层导热系数、井筒倾斜角度、注水层渗透率,明确影响注水井温度剖面的主控因素为注入水温度、注水时间和注入量。采用模拟退火(Simulated Annealing,SA)算法建立注水井DTS数据反演模型,对一口注水井现场实测DTS数据进行反演,获得较为准确的吸水剖面,单层最大吸水量误差百分比14.25%,平均误差11.09%,验证该反演方法的可靠性。通过DTS数据反演可以实现注水井吸水剖面定量解释,为注水效果评价提供直接依据。

基于QUBO模型的信用卡最优获利组合规划

在银行信用卡或相关的贷款业务中,为最大化银行收益、方便银行对客户授信,针对不同信用卡设定不同阈值的情况下进行投资组合,对模拟数据进行归一化处理,建立信用卡最优投资组合二次无约束二值优化(QUBO)模型,使用模拟退火算法求解模型得到单一信用卡与三张信用卡的最大收益阈值组合。进一步通过量子降维方法优化二次无约束二值优化(QUBO)模型,最终得到信用卡选择与阈值的双重最优组合,得出最大收益,辅助提高银行的业务竞争能力。

量子退火反演的原理和实现

现有的非线性反演方法,大都存在着求解的局部收敛性和计算速度慢的问题.在与模拟退火方法进行比较的基础上,本文研究了基于量子跃迁过程中量子隧道效应的量子退火反演算法.数值试验结果表明,量子退火方法应用于地球物理反问题的求解是成功的,它适合于非线性、多极值的地球物理反演问题,与模拟退火反演相比,量子退火反演在退火收敛速度和避免陷入局部极小等方面有着一定的优势,该方法也适用于其他领域非线性最优化问题的求解,具有较强的普适性.

重力与地震资料的模拟退火约束联合反演

联合反演是综合地球物理研究的重要定量解释手段.本文在总结和分析重力与地震资料联合反演的研究现状基础上,利用改进的全局寻优的快速模拟退火算法,实现了重力和地震资料的约束同步联合反演.针对性地设计了密度和速度界面不完全一致的模型,理论模型的试验说明了方法的效果和适用性.结合最近完成的广东徐闻地区实际资料的处理和解释,表明该方法可准确确定复杂构造物性界面的密度和速度结构,在该地区的油气勘探中发挥了作用.在先验信息约束下,该联合反演方法要明显优于单独的重力反演.

大地电磁与地震资料仿真退火约束联合反演

在对仿真退火算法研究的基础上 ,将非常快速仿真退火的连续模型空间改为可变的离散化形式 ,理论模型试算表明 ,使用本文方法可提高工作效率 5— 1 0倍 .为适应联合反演的需要 ,对非常快速仿真退火的误差“单判断”检验准则改为误差“双判断”检验准则 ,避免Metropolis接受准则的判断失误 .在此基础上 ,实现了一维及二维起伏地形条件下大地电磁与地震资料多参量信息的联合反演 .

MT-重力模拟退火联合反演研究

为了合理互补不同地球物理场的优势和特点,本文研究了MT与重力模拟退火联合反演的技术.在分析MT与重力联合反演的必要性和可行性后,讨论并研究了主要技术难点及解决方法.重点解决了模型扰动、MT与重力界面不一致的处理、目标函数的加权联合问题,提出MT-重力模拟退火反演(MT-GSA)算法.在此基础上进行了理论模型试验和实际资料处理,取得了较好的效果.

波阻抗反演正则参数估计

为了解决用正则化方法能够将波阻抗反演的病态问题转为良态问题 ,通过统计方法合理地选择正则参数的初值 ,在反演过程中用极大似然 (ML)方法实时进行正则参数值估计 ,提高反演收敛速度 ,改善反演结果 .同时 ,在具体反演中将正则化方法与快速模拟退火算法相结合 ,充分发挥正则参数作用 ,可以获得全局最优解 ,取得了好的实际应用效果 .

基于宽范围岩石物性约束的大地电磁和地震联合反演

岩石物性约束是地球物理联合反演重要的实现方式.在以往联合反演研究中,这种约束通常以点对点的映射方式出现,要求经验性的岩石物性关联是相对精确的,无形中提高了岩石物性约束应用于联合反演的条件.基于此,本文结合全局寻优的模拟退火算法,提出了宽范围岩石物性约束技术.该技术将岩石物性约束与模拟退火模型扰动、模型接受准则相结合,实现了空间对空间的映射,将电阻率和速度耦合在一起.文章以MT和地震正则化同步联合反演为例,检验了不同的先验信息条件下的宽范围岩石物性约束技术的适用性.模型试验表明:新技术容易实现,容错性高,可降低"不精确"岩石物性关联信息引入带来的风险,提高岩石物性约束应用的灵活性.

基于L1范数的瞬变电磁非线性反演

瞬变电磁反演存在高度的非线性特征,常用的最小二乘等线性反演方法往往对初始模型高度依赖,并且极易陷入局部最优解.本文基于观测数据与模拟数据的L1范数建立目标函数,采用模拟退火非线性全局最优化方法实现瞬变电磁一维反演.初始模型完全随机产生,通过指数函数退温机制模拟系统能量最小实现迭代,通过接收概率函数评价当前模型,实现局部最优解的跳出,最终实现全局最优化求解.通过数值算例发现,无论给定的反演层数等于还是大于设计模型,都可以获得较好的反演效果,因而可以在反演初始就设计较多的层数,实现反演模型的自动拟合;同时,利用含噪声数据反演进一步验证算法的稳定性.最后,对实测数据进行了反演测试,结果与钻孔编录基本一致,表明提出的基于L1范数的模拟退火反演可用于实测数据处理.

大地电磁与地震正则化同步联合反演

文中在于鹏等提出的电阻率和速度随机分布的大地电磁与地震联合反演方法的基础上,将Tikhonov正则化思想引入到联合反演中,加入先验信息进行模型约束,以最小模型为稳定器,采用L曲线方法来确定近似最佳的正则化因子。考虑到线性寻优算法容易陷入局部极小,文中采用非线性的模拟退火方法来实现大地电磁与地震的同步联合反演。通过模型试验的对比分析,我们认为加入有效模型约束的正则化联合反演可以比单纯考虑数据拟合的联合反演和单独反演方法更有效地提高解的稳定性和计算效率,获得更接近实际而且稳定的解。

波阻抗反演技术的研究现状及发展

波阻抗信息是联系地质和地球物理的一座桥梁,而波阻抗反演在地震反演中具有特殊的地位。介绍了波阻抗反演技术的研究现状,对各种反演方法进行了分类,总结出各类方法的特点,并指出弹性波阻抗反演的出现将成为反演进一步发展的方向之一,地震反演正走向常规波阻抗反演和弹性波阻抗反演相结合的道路。

航天飞机极化干涉雷达数据反演地表植被参数

利用基于极化干涉测量的基本原理和相干散射模型,提出了基于模拟加温-退火算法的极化干涉雷 达数据地表植被参数的反演算法。首先,对极化干涉测量的基本原理和一个考虑了地表和植被散射的二层相 干散射模型进行了阐述。接着,对模拟退火算法的基本理论和基于模拟加温-退火算法的地表植被参数反演 模型进行了论述。最后,利用和田地区1994年10月9日和10日的航天飞机SIR-C L波段单视散射矩阵复数 据进行了地表植被参数反演的计算,将反演结果与实测数据比较,表明该反演算法能以较好的精度获取地表 植被的高度。