In eld seismic data acquisition,seismic traces are often aected by substantial data gaps and strong noise interference due to environmental and instrumental factors,thus degrading the resolution and signalto-noise rat...In eld seismic data acquisition,seismic traces are often aected by substantial data gaps and strong noise interference due to environmental and instrumental factors,thus degrading the resolution and signalto-noise ratio(SNR)of the seismic profiles.Effective seismic data reconstruction and noise suppression techniques are therefore essential to recover missing signals and improve data quality.In this study,a fast projection onto convex sets(FPOCS)algorithm is proposed by incorporating an inertial parameter that involves a linear combination of the two preceding iterations based on the traditional projection onto convex sets(POCS)algorithm.Then,a weighting factor is introduced to achieve simultaneous data reconstruction and noise suppression using the weighted fast projection onto convex sets(WFPOCS)algorithm.To further suppress residual random noise in the updated solution,an optimization strategy is adopted by swapping the order of the iterative hard thresholding operator and the projection operator.The nal algorithm,termed the improved weighted fast projection onto convex sets(IWFPOCS),achieves high-efciency reconstruction and effective noise suppression.Compared with WFPOCS,the proposed method maintains fast reconstruction speed while demonstrating superior denoising performance on irregularly missing and noisy datasets.Field data experiments conrm that the proposed method signicantly improves the SNR and resolution of seismic data,oering strong practical potential for subsequent processing and interpretation.展开更多
High-temperature rockbursts pose a critical challenge in deep underground engineering and resource exploitation.Consequently,predicting high-geothermal rockbursts has become a key scientific objective.In this paper,a ...High-temperature rockbursts pose a critical challenge in deep underground engineering and resource exploitation.Consequently,predicting high-geothermal rockbursts has become a key scientific objective.In this paper,a genetic projection pursuit algorithm(GPPA)is proposed for the prediction of high-geothermal rockbursts by introducing the coefficient K,and utilizing multiple empirical criteria(Wet index,σc/σt,σθ/σc,andσ1/σc).Four empirical criteria were statistically analyzed for 147 sets of rockburst cases,yielding accuracies of 40%,39%,46%and 29%,respectively.After the implantation of optimal segmentation,there was an enhancement in accuracy by 12%,9%,6%,and 19%,respectively.Theσθ/σc criterion exhibited superior performance,with a baseline accuracy of 46%.The GPPA model was tested and validated using four characteristic parameters(Wet index,σc/σt,σθ/σc,andσ1/σc)as inputs,revealing that the error ranged between 0.07 and 0.41.Successful validation was performed in the Sangzhuling Tunnel(four slight rockbursts)and Qirehataer Diversion Tunnel(one moderate rockburst),which matched field observations.Consequently,the proposed model offers guidance for predicting high-geothermal rockburst hazards.展开更多
针对永磁同步电机单矢量模型预测控制在一个周期内只有一个基本电压矢量作用于逆变器,从而造成电流和转矩波动较大,尽管双矢量模型预测控制在一定程度能够改善该问题,但其电压矢量通过遍历法选择,存在计算量大、实时性差等问题,因此提...针对永磁同步电机单矢量模型预测控制在一个周期内只有一个基本电压矢量作用于逆变器,从而造成电流和转矩波动较大,尽管双矢量模型预测控制在一定程度能够改善该问题,但其电压矢量通过遍历法选择,存在计算量大、实时性差等问题,因此提出了一种基于灰狼算法(Grey Wolf Optimizer,GWO)优化BP(Back Propagation,BP)神经网络的永磁同步电机控制方法。将原系统选择最优电压矢量过程看作是一种神经网络分类任务,通过原系统产生的大量离散数据离线训练网络,并利用GWO算法优化BP神经网络的初始权值和偏置,加快神经网络的训练速度和精度,训练好的网络代替模型预测控制,避免矢量遍历选择。最后仿真验证了该控制策略的可行性,有效的减小了电流和转矩的波动,提高了系统控制性能。展开更多
基金supported in part by the Foundation of National Key Laboratory of Uranium Resources Exploration-Mining and Nuclear Remote Sensing under Grant 2024QZ-TD-13in part by the National Natural Science Foundation of China under Grant 42564006+1 种基金in part by the Natural Science Foundation of Jiangxi Province under Grant 20242BAB26051in part by the Open Fund of SINOPEC Key Laboratory of Geophysics,and in part by support the plan of Ganpo Juncai under Grant 20243BCE51012.
摘要In eld seismic data acquisition,seismic traces are often aected by substantial data gaps and strong noise interference due to environmental and instrumental factors,thus degrading the resolution and signalto-noise ratio(SNR)of the seismic profiles.Effective seismic data reconstruction and noise suppression techniques are therefore essential to recover missing signals and improve data quality.In this study,a fast projection onto convex sets(FPOCS)algorithm is proposed by incorporating an inertial parameter that involves a linear combination of the two preceding iterations based on the traditional projection onto convex sets(POCS)algorithm.Then,a weighting factor is introduced to achieve simultaneous data reconstruction and noise suppression using the weighted fast projection onto convex sets(WFPOCS)algorithm.To further suppress residual random noise in the updated solution,an optimization strategy is adopted by swapping the order of the iterative hard thresholding operator and the projection operator.The nal algorithm,termed the improved weighted fast projection onto convex sets(IWFPOCS),achieves high-efciency reconstruction and effective noise suppression.Compared with WFPOCS,the proposed method maintains fast reconstruction speed while demonstrating superior denoising performance on irregularly missing and noisy datasets.Field data experiments conrm that the proposed method signicantly improves the SNR and resolution of seismic data,oering strong practical potential for subsequent processing and interpretation.
基金supported by the National Natural Science Foundation of China(Grant No.42130719)the Opening Foundation of Key Laboratory of Landslide Risk Early-warning and Control,Ministry of Emergency Management(Chengdu University of Technology)(Grant No.KLLREC2022K003)the Humanities and Social Sciences Youth Foundation,Ministry of Education(Grant No.23YJCZH051).
摘要High-temperature rockbursts pose a critical challenge in deep underground engineering and resource exploitation.Consequently,predicting high-geothermal rockbursts has become a key scientific objective.In this paper,a genetic projection pursuit algorithm(GPPA)is proposed for the prediction of high-geothermal rockbursts by introducing the coefficient K,and utilizing multiple empirical criteria(Wet index,σc/σt,σθ/σc,andσ1/σc).Four empirical criteria were statistically analyzed for 147 sets of rockburst cases,yielding accuracies of 40%,39%,46%and 29%,respectively.After the implantation of optimal segmentation,there was an enhancement in accuracy by 12%,9%,6%,and 19%,respectively.Theσθ/σc criterion exhibited superior performance,with a baseline accuracy of 46%.The GPPA model was tested and validated using four characteristic parameters(Wet index,σc/σt,σθ/σc,andσ1/σc)as inputs,revealing that the error ranged between 0.07 and 0.41.Successful validation was performed in the Sangzhuling Tunnel(four slight rockbursts)and Qirehataer Diversion Tunnel(one moderate rockburst),which matched field observations.Consequently,the proposed model offers guidance for predicting high-geothermal rockburst hazards.
摘要针对现有变电站碳排放量预测模型存在考虑指标较少、数据更新慢等问题,本文提出一种基于改进萤火虫算法(improved firefly algorithm,IFA)优化反向传播(back propagation,BP)神经网络的变电站碳排放预测模型。首先,针对萤火虫算法(firefly algorithm,FA)收敛速度过慢以及易陷入局部最优等问题,引入教与学因子,修改萤火虫位置更新过程,以提高群体适应度。其次,引入IFA算法对BP神经网络模型进行超参数寻优,并构建IFA-BP神经网络预测模型。然后,基于CRITIC法筛选预测模型输入层的关键碳排放指标。最后,利用训练集数据训练预测模型,基于训练好的模型对变电站的碳排放量进行预测。仿真结果表明,相较于3种对比方案,本文IFA-BP神经网络预测模型分别在均方根误差(root mean square error,RMSE)上降低59.61%、15.77%和26.65%,在决定系数(coefficient of determination,R2)上提高5.66%、1.46%和1.15%,充分验证了本文所提变电站碳排放预测模型的可行性与优越性。
摘要针对永磁同步电机单矢量模型预测控制在一个周期内只有一个基本电压矢量作用于逆变器,从而造成电流和转矩波动较大,尽管双矢量模型预测控制在一定程度能够改善该问题,但其电压矢量通过遍历法选择,存在计算量大、实时性差等问题,因此提出了一种基于灰狼算法(Grey Wolf Optimizer,GWO)优化BP(Back Propagation,BP)神经网络的永磁同步电机控制方法。将原系统选择最优电压矢量过程看作是一种神经网络分类任务,通过原系统产生的大量离散数据离线训练网络,并利用GWO算法优化BP神经网络的初始权值和偏置,加快神经网络的训练速度和精度,训练好的网络代替模型预测控制,避免矢量遍历选择。最后仿真验证了该控制策略的可行性,有效的减小了电流和转矩的波动,提高了系统控制性能。