parameter optimization

参数优化
  • 文章类型: Journal Article
    本研究探索了用于储层流入预测的机器学习算法,包括长短期记忆(LSTM),随机森林(RF),和元启发式优化模型。研究了离散小波变换(DWT)和XGBoost特征选择等特征工程技术的影响。LSTM显示出希望,LSTM-XGBoost在训练中表现出从179.81m3/sRMSE(均方根误差)到测试中的49.42m3/s的强泛化。RF-XGBoost和模型结合DWT,比如LSTM-DWT和RF-DWT,也表现得很好,强调特征工程的重要性。比较说明了DWT的增强:LSTM和RF在使用DWT时大大减少了训练和测试RMSE。MLP-ABC和LSSVR-PSO等元启发式模型也受益于DWT,LSSVR-PSO-DWT模型具有出色的预测准确性,培训中显示133.97m3/sRMSE,测试中显示47.08m3/sRMSE。该模型协同地结合了LSSVR,PSO,和DWT,通过有效捕获复杂的水库流入模式,成为表现最好的人。
    This research explores machine learning algorithms for reservoir inflow prediction, including long short-term memory (LSTM), random forest (RF), and metaheuristic-optimized models. The impact of feature engineering techniques such as discrete wavelet transform (DWT) and XGBoost feature selection is investigated. LSTM shows promise, with LSTM-XGBoost exhibiting strong generalization from 179.81 m3/s RMSE (root mean square error) in training to 49.42 m3/s in testing. The RF-XGBoost and models incorporating DWT, like LSTM-DWT and RF-DWT, also perform well, underscoring the significance of feature engineering. Comparisons illustrate enhancements with DWT: LSTM and RF reduce training and testing RMSE substantially when using DWT. Metaheuristic models like MLP-ABC and LSSVR-PSO benefit from DWT as well, with the LSSVR-PSO-DWT model demonstrating excellent predictive accuracy, showing 133.97 m3/s RMSE in training and 47.08 m3/s RMSE in testing. This model synergistically combines LSSVR, PSO, and DWT, emerging as the top performers by effectively capturing intricate reservoir inflow patterns.
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  • 文章类型: Journal Article
    负荷频率调节(LFR)是电力生产规划中不可缺少的方案,可靠和不间断的电源。面对复杂的电力系统(PS)结构和日益复杂的电力需求,新的控制器,不仅提供良好的性能,但在实践中也需要易于调试。为此,这项研究引入了指数PID(EXP-PID)控制器作为一种新的控制方案,以改善PS的LFR性能。该控制器设计简单,具有从两个可调指数函数继承的非线性特征,它们被放置在PID控制器前面,并分别作用于误差信号及其时间导数。为了实现最大的性能,EXP-PID控制器的参数由蛇形优化器(co-SO)的校正变体获得。为了验证提出的控制方案,在该区域中受到青睐的各种单/多区域单/多源PSs被视为测试台。与最先进的方法进行了彻底的比较,以揭示我们的建议的真正功效。在竞争对手中,协同调整EXP-PID控制器,尽管它很简单,发现在有效减轻频率和联络线功率偏差方面具有可靠和有希望的性能。
    Load frequency regulation (LFR) is an indispensable scheme in planning electrical power production to provide consumers with stable, reliable and uninterrupted power. In the face of complicated power system (PS) structures with increasing and intricate power demand, new controllers that offer not only good performance, but also easy commissioning in practice are required. To this end, this research introduces an exponential PID (EXP-PID) controller as a new control scheme to ameliorate the LFR performance of PSs. This controller is simple to design and has a nonlinear feature inherited from two tunable exponential functions, which are placed in front of the PID controller and act on the error signal and its time derivative individually. To achieve the utmost performance, the EXP-PID controller\'s parameters are procured by a corrected variant of the snake optimizer (co-SO). To validate the proposed control scheme, various single-/multi-area single-/multi-source PSs favored in the area are considered as test benches. A thorough comparison with the state-of-the-art approaches is performed to disclose the true efficacy of our proposal. Among the rivals, co-SO tuned EXP-PID controller, despite its simplicity, is found to render credible and promising performance in mitigating frequency and tie-line power deviations effectively.
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  • 文章类型: Journal Article
    厌氧消化(AD)具有处理有机废物的巨大潜力,取得了显著的效果。然而,这是很难建立一个准确的力学模型为这一过程。数据驱动建模技术为解决这一问题打开了新的大门。当样品组较小时,传统的数据驱动建模方法往往无能为力。在本文中,为小样本场景下的数据驱动高精度建模提供了一种有效的方法。首先利用时间序列生成对抗网络(TimeGAN)来增强在AD甲烷生产期间收集的原始高质量小样本数据。然后设计了一种新颖的混合内核极限学习机(HKELM),以形成更好的数据驱动模型结构,其正则化系数C0通过麻雀搜索算法(SSA)进行优化。最后,该半成品模型(SSA-HKELM)由增强数据训练,以形成AD甲烷生成过程的最终数学模型(TimeGAN-SSA-HKELM)。甲烷日产量预测误差对比实验验证了该方法的有效性,可以扩展到其他类似的小样本数据驱动建模场景。
    Anaerobic digestion (AD) has the great potential to treat organic waste and achieve remarkable results effectively. However, it is very tough to establish an accurate mechanistic model for this process. Data-driven modeling technology has opened a new door to solving this problem. While when the sample set is small, traditional data-driven modeling methods are often powerless. In this paper, an effective method is proposed for data-driven high-precision modeling in small sample scenarios. A time series generative adversarial network (TimeGAN) is first utilized to augment the original high-quality small-sample data collected during the AD methane production. A novel hybrid kernel extreme learning machine (HKELM) is then designed to form a better structure of the data-driven model, whose regularization coefficient C0 is optimized by the sparrow search algorithm (SSA). Finally, this semi-finished model (SSA-HKELM) is trained by the augmented data to form the final mathematical model (TimeGAN-SSA-HKELM) for the AD methane generation process. Comparative experiments of the methane daily production prediction error have verified the effectiveness of the method, which can be extended to other similar small sample data-driven modeling scenarios.
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  • 文章类型: Journal Article
    在本文中,一种新颖的飞蛾火焰优化(MFO)算法,即多改进策略增强的MFO算法(MISMFO)用于求解多核支持向量回归器(MKSVR)中的参数优化,并进一步采用MISMFO-MKSVR模型来处理软件工作量估计问题。在MISMFO,逻辑混沌映射用于增加初始种群多样性,同时进行了突变和火焰数分阶段减少机制,以提高搜索效率,以及自适应权重调整机制,以加速收敛和平衡探索和开发。在15个基准函数和CEC2020测试集上验证了MISMFO模型。结果表明,MISMFO在收敛速度和精度方面优于其他元启发式算法和MFO变体。此外,在5个软件工作量数据集上对MISMFO-MKSVR模型进行了仿真测试,结果表明该模型在软件工作量估计问题上具有更好的性能。MISMFO的Matlab代码可以在https://github.com/loadstar1997/MISMFO找到。
    In this paper, a novel Moth-Flame Optimization (MFO) algorithm, namely MFO algorithm enhanced by Multiple Improvement Strategies (MISMFO) is proposed for solving parameter optimization in Multi-Kernel Support Vector Regressor (MKSVR), and the MISMFO-MKSVR model is further employed to deal with the software effort estimation problems. In MISMFO, the logistic chaotic mapping is applied to increase initial population diversity, while the mutation and flame number phased reduction mechanisms are carried out to improve the search efficiency, as well the adaptive weight adjustment mechanism is used to accelerate convergence and balance exploration and exploitation. The MISMFO model is verified on fifteen benchmark functions and CEC 2020 test set. The results show that the MISMFO has advantages over other meta-heuristic algorithms and MFO variants in terms of convergence speed and accuracy. Additionally, the MISMFO-MKSVR model is tested by simulations on five software effort datasets and the results demonstrate that the proposed model has better performance in software effort estimation problem. The Matlab code of MISMFO can be found at https://github.com/loadstar1997/MISMFO .
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  • 文章类型: Journal Article
    果蔬新鲜度检测可以提高农产品管理效率,减少资源浪费和经济损失,在提高果蔬农产品附加值方面发挥着至关重要的作用。目前,果蔬新鲜度的检测主要依靠人工特征提取结合机器学习。然而,人工提取特征存在适应性差的问题,导致水果和蔬菜新鲜度检测效率低。尽管有一些研究引入了深度学习方法来自动学习表征水果和蔬菜新鲜度的深度特征,以应对复杂场景中的多样性和可变性。然而,这些果蔬新鲜度检测研究的性能有待进一步提高。基于此,本文提出了一种融合不同深度学习模型提取果蔬图像特征及图像中各区域间相关性的新方法,从而更客观准确地检测水果和蔬菜的新鲜度。首先,根据深度学习模型的输入要求,调整数据集中的图像大小。然后,融合深度学习模型提取了表征果蔬新鲜度的深层特征。最后,基于融合的深度学习模型的检测性能,优化融合模型的参数,并对果蔬新鲜度检测性能进行了评价。实验结果表明,CNN_BiLSTM深度学习模型,其中融合了卷积神经网络(CNN)和双向长短期记忆神经网络(BiLSTM),结合参数优化处理,在果蔬新鲜度检测中的准确率达到97.76%。研究结果表明,该方法有望提高果蔬新鲜度检测的性能。
    Fruit and vegetable freshness testing can improve the efficiency of agricultural product management, reduce resource waste and economic losses, and plays a vital role in increasing the added value of fruit and vegetable agricultural products. At present, the detection of fruit and vegetable freshness mainly relies on manual feature extraction combined with machine learning. However, manual extraction of features has the problem of poor adaptability, resulting in low efficiency in fruit and vegetable freshness detection. Although exist some studies that have introduced deep learning methods to automatically learn deep features that characterize the freshness of fruits and vegetables to cope with the diversity and variability in complex scenes. However, the performance of these studies on fruit and vegetable freshness detection needs to be further improved. Based on this, this paper proposes a novel method that fusion of different deep learning models to extract the features of fruit and vegetable images and the correlation between various areas in the image, so as to detect the freshness of fruits and vegetables more objectively and accurately. First, the image size in the dataset is resized to meet the input requirements of the deep learning model. Then, deep features characterizing the freshness of fruits and vegetables are extracted by the fused deep learning model. Finally, the parameters of the fusion model were optimized based on the detection performance of the fused deep learning model, and the performance of fruit and vegetable freshness detection was evaluated. Experimental results show that the CNN_BiLSTM deep learning model, which fusion convolutional neural network (CNN) and bidirectional long-short term memory neural network (BiLSTM), is combined with parameter optimization processing to achieve an accuracy of 97.76% in detecting the freshness of fruits and vegetables. The research results show that this method is promising to improve the performance of fruit and vegetable freshness detection.
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  • 文章类型: Journal Article
    本文讨论了针对体声波运动参数的新型固态传感器的优化设计和特性的科学技术问题,以提高信噪比和信息信号在其自身噪声和干扰背景下的可检测性。选择结构元件材料的标准,包括敏感元件的压电换能器,被识别;使用开发的程序进行了相应的数值模拟;并根据建议的方法进行了实验研究,以验证获得的分析和计算位置。实验结果揭示了所选择的设计参数和特性优化标准的正确性,证明了建模结果和现场研究结果之间的高度相关性,and,因此,证实了在高动态物体的导航和控制系统中使用这种新型的运动参数固态声学传感器的前景。
    The present paper discusses the scientific and technical problem of optimizing the design and characteristics of a new type of solid-state sensors for motion parameters on bulk acoustic waves in order to increase the signal-to-noise ratio and the detectability of an informative signal against the background of its own noise and interference. Criteria for choosing materials for structural elements, including piezoelectric transducers of the sensitive element, were identified; a corresponding numerical simulation was performed using the developed program; and experimental studies according to the suggested method were carried out to validate the obtained analytical and calculated positions. The experimental results revealed the correctness of the chosen criteria for the optimization of design parameters and characteristics, demonstrated the high correlation between the results of modeling and field studies, and, thus, confirmed the prospects of using this new type of solid-state acoustic sensors of motion parameters in the navigation and control systems of highly dynamic objects.
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  • 文章类型: Journal Article
    局部共振超材料通常具有较窄的带隙,这极大地限制了它们在现实工程环境中的应用。在本文中,提出了一种基于遗传算法的优化方法,通过合并多个分离的带隙来扩大多谐振压电超材料的带隙。利用有效介质理论,首先得到了超材料板的等效抗弯刚度和色散关系。然后,提供并分析了在有阻尼和无阻尼两种情况下确定带隙范围的标准。此外,基于带隙合并现象,提出了一种基于遗传算法的带隙展宽优化方法。通过研究在没有阻尼和有阻尼的情况下的带隙加宽效应,发现,当没有阻尼时,带隙只能稍微加宽;而在传递函数中引入阻尼后,带隙可以显着加宽200%以上。通过与有限元仿真结果的对比,验证了带隙展宽效果。
    Locally resonant metamaterials usually have narrow bandgaps, which significantly limits their applications in realistic engineering environments. In this paper, an optimization method based on the genetic algorithm is proposed to broaden bandgaps in multi-resonant piezoelectric metamaterial through the merging of multiple separated bandgaps. Using the effective medium theory, the equivalent bending stiffness and dispersion relationship of a metamaterial plate are first obtained. Then, the criteria for determining the bandgap ranges for the two cases with and without damping are provided and analyzed. Furthermore, based on the bandgap merging phenomena, an optimization method for widening the bandgap is proposed based on the genetic algorithm. By investigating the bandgap widening effects in cases without and with damping, it is found that, when there is no damping, the bandgap can only be slightly widened; while after introducing damping into the transfer functions, the bandgap can be significantly widened by more than 200%. The bandgap widening effects are verified by comparing with finite element simulation results.
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  • 文章类型: Journal Article
    特征检测在非目标筛查(NTS)中起着至关重要的作用,需要仔细选择算法参数以最小化假阳性(FP)特征。在这项研究中,采用随机方法来优化用于处理高分辨率质谱数据的特征检测算法的参数设置.使用四种开源算法(OpenMS,SAFD,XCMS,和KPIC2)在patRoon软件平台内,用于处理饮用水样品中掺入46种全氟和多氟烷基物质(PFAS)的提取物。设计的方法基于随机策略,该策略涉及从变量空间中进行随机抽样,并使用Pearson相关性来评估每个参数对检测到的可疑分析物数量的影响。用我们的方法,在SAFD和XCMS的情况下,优化的参数通过增加可疑命中来提高算法性能,并减少检测到的特征的总数(即,最小化FP)用于OpenMS。这些改进在三个不同的饮用水样品作为测试数据集上进一步验证。与默认参数相比,优化参数导致较低的错误发现率(FDR%)。有效地增加了对真正特征的检测。这项工作还强调了在启动NTS之前进行算法参数优化以降低此类数据集的复杂性的必要性。
    Feature detection plays a crucial role in non-target screening (NTS), requiring careful selection of algorithm parameters to minimize false positive (FP) features. In this study, a stochastic approach was employed to optimize the parameter settings of feature detection algorithms used in processing high-resolution mass spectrometry data. This approach was demonstrated using four open-source algorithms (OpenMS, SAFD, XCMS, and KPIC2) within the patRoon software platform for processing extracts from drinking water samples spiked with 46 per- and polyfluoroalkyl substances (PFAS). The designed method is based on a stochastic strategy involving random sampling from variable space and the use of Pearson correlation to assess the impact of each parameter on the number of detected suspect analytes. Using our approach, the optimized parameters led to improvement in the algorithm performance by increasing suspect hits in case of SAFD and XCMS, and reducing the total number of detected features (i.e., minimizing FP) for OpenMS. These improvements were further validated on three different drinking water samples as test dataset. The optimized parameters resulted in a lower false discovery rate (FDR%) compared to the default parameters, effectively increasing the detection of true positive features. This work also highlights the necessity of algorithm parameter optimization prior to starting the NTS to reduce the complexity of such datasets.
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  • 文章类型: Journal Article
    数据无关采集(DIA)技术如所有理论质谱(SWATH)采集的顺序窗口采集已经成为蛋白质组分析的优选策略。我们的研究使用窄隔离窗口放置方法优化了SWATH-DIA方法,提高其蛋白质组学性能。我们优化了ZenoTOF7600(Sciex)上具有不同宽度(1.9和2.9Da)的窄隔离窗口的采集参数组合;使用DIA-NN(版本1.8.1)分析获得的数据。窄SWATH(nSWATH)在消化的肽上鉴定了5916和7719蛋白质组,对应于来自小鼠肝脏和HEK293T细胞的400ng蛋白质,分别,识别率提高7.52%和4.99%,分别,与传统的SWATH相比。定量值的中值变异系数小于6%。我们进一步分析了200ng的基准样品,包括来自已知比例的大肠杆菌的肽,酵母,和使用nSWATH的人肽。因此,它达到了与传统SWATH相当的准确性和精密度,在三个基准样本中平均鉴定了95,456个前体和9342个蛋白质组,与传统SWATH相比,分别提高了12.6%和9.63%的识别率。nSWATH方法改进了各种加载量基准样品的识别,在25ng时鉴定出40.7%以上的蛋白质组。这些结果表明,nSWATH的性能得到了改善,有助于从复杂的生物样品中获得更深的蛋白质组数据。
    Data-independent acquisition (DIA) techniques such as sequential window acquisition of all theoretical mass spectra (SWATH) acquisition have emerged as the preferred strategies for proteomic analyses. Our study optimized the SWATH-DIA method using a narrow isolation window placement approach, improving its proteomic performance. We optimized the acquisition parameter combinations of narrow isolation windows with different widths (1.9 and 2.9 Da) on a ZenoTOF 7600 (Sciex); the acquired data were analyzed using DIA-NN (version 1.8.1). Narrow SWATH (nSWATH) identified 5916 and 7719 protein groups on the digested peptides, corresponding to 400 ng of protein from mouse liver and HEK293T cells, respectively, improving identification by 7.52 and 4.99%, respectively, compared to conventional SWATH. The median coefficient of variation of the quantified values was less than 6%. We further analyzed 200 ng of benchmark samples comprising peptides from known ratios ofEscherichia coli, yeast, and human peptides using nSWATH. Consequently, it achieved accuracy and precision comparable to those of conventional SWATH, identifying an average of 95,456 precursors and 9342 protein groups across three benchmark samples, representing 12.6 and 9.63% improved identification compared to conventional SWATH. The nSWATH method improved identification at various loading amounts of benchmark samples, identifying 40.7% more protein groups at 25 ng. These results demonstrate the improved performance of nSWATH, contributing to the acquisition of deeper proteomic data from complex biological samples.
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  • 文章类型: Journal Article
    在不同类型的高速逆流色谱(HSCCC)中,使用磺丁基醚-β-环糊精(SBE-β-CD)作为手性选择剂,开发了一种连续分离伏立康唑对映体的有效方法。使用由正己烷/乙酸乙酯/100mmol/L磷酸盐缓冲溶液(pH=3.0,含有50mmol/LSBE-β-CD)(1.5:0.5:2,v/v/v)组成的两相溶剂系统进行分离。使用分析DEHSCCC仪器实现了快速且可预测的放大过程。随后将优化的参数应用于制备型TautoHSCCC仪器,导致一致的分离时间和对映体纯度,吞吐量提高了11倍。制备HSCCC成功分离出506mg的外消旋体,提供超过99%纯度的对映异构体,如高效液相色谱分析所证实。这项研究提供了一种有效的方法来预测HSCCC的放大过程并实现手性药物的连续分离。
    An efficient method for the continuous separation of Voriconazole enantiomers was developed using sulfobutyl ether-β-cyclodextrin (SBE-β-CD) as a chiral selector in high-speed countercurrent chromatography (HSCCC) with different types. The separation was performed using a two-phase solvent system consisting of n-hexane/ethyl acetate/100 mmol/L phosphate buffer solution (pH = 3.0, containing 50 mmol/L SBE-β-CD) (1.5:0.5:2, v/v/v). A fast and predictable scale-up process was achieved using an analytical DE HSCCC instrument. The optimized parameters were subsequently applied to a preparative Tauto HSCCC instrument, resulting in consistent separation time and enantiomeric purity, with throughput boosted by a remarkable 11-fold. Preparative HSCCC successfully separated 506 mg of the racemate, delivering enantiomers exceeding 99% purity as confirmed by high-performance liquid chromatography analysis. This investigation presents an effective methodology for forecasting the HSCCC scale-up process and attaining continuous separation of chiral drugs.
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