Machine Learning Techniques in Predicting Hot Deformation Behavior of Metallic Materials

In engineering practice,it is often necessary to determine functional relationships between dependent and independent variables.These relationships can be highly nonlinear,and classical regression approaches cannot always provide sufficiently reliable solutions.Nevertheless,Machine Learning(ML)techniques,which offer advanced regression tools to address complicated engineering issues,have been developed and widely explored.This study investigates the selected ML techniques to evaluate their suitability for application in the hot deformation behavior of metallic materials.The ML-based regression methods of Artificial Neural Networks(ANNs),Support Vector Machine(SVM),Decision Tree Regression(DTR),and Gaussian Process Regression(GPR)are applied to mathematically describe hot flow stress curve datasets acquired experimentally for a medium-carbon steel.Although the GPR method has not been used for such a regression task before,the results showed that its performance is the most favorable and practically unrivaled;neither the ANN method nor the other studied ML techniques provide such precise results of the solved regression analysis.

Prediction of Shear Bond Strength of Asphalt Concrete Pavement Using Machine Learning Models and Grid Search Optimization Technique

Determination of Shear Bond strength(SBS)at interlayer of double-layer asphalt concrete is crucial in flexible pavement structures.The study used three Machine Learning(ML)models,including K-Nearest Neighbors(KNN),Extra Trees(ET),and Light Gradient Boosting Machine(LGBM),to predict SBS based on easily determinable input parameters.Also,the Grid Search technique was employed for hyper-parameter tuning of the ML models,and cross-validation and learning curve analysis were used for training the models.The models were built on a database of 240 experimental results and three input variables:temperature,normal pressure,and tack coat rate.Model validation was performed using three statistical criteria:the coefficient of determination(R2),the Root Mean Square Error(RMSE),and the mean absolute error(MAE).Additionally,SHAP analysis was also used to validate the importance of the input variables in the prediction of the SBS.Results show that these models accurately predict SBS,with LGBM providing outstanding performance.SHAP(Shapley Additive explanation)analysis for LGBM indicates that temperature is the most influential factor on SBS.Consequently,the proposed ML models can quickly and accurately predict SBS between two layers of asphalt concrete,serving practical applications in flexible pavement structure design.

Congruent Feature Selection Method to Improve the Efficacy of Machine Learning-Based Classification in Medical Image Processing

Machine learning(ML)is increasingly applied for medical image processing with appropriate learning paradigms.These applications include analyzing images of various organs,such as the brain,lung,eye,etc.,to identify specific flaws/diseases for diagnosis.The primary concern of ML applications is the precise selection of flexible image features for pattern detection and region classification.Most of the extracted image features are irrelevant and lead to an increase in computation time.Therefore,this article uses an analytical learning paradigm to design a Congruent Feature Selection Method to select the most relevant image features.This process trains the learning paradigm using similarity and correlation-based features over different textural intensities and pixel distributions.The similarity between the pixels over the various distribution patterns with high indexes is recommended for disease diagnosis.Later,the correlation based on intensity and distribution is analyzed to improve the feature selection congruency.Therefore,the more congruent pixels are sorted in the descending order of the selection,which identifies better regions than the distribution.Now,the learning paradigm is trained using intensity and region-based similarity to maximize the chances of selection.Therefore,the probability of feature selection,regardless of the textures and medical image patterns,is improved.This process enhances the performance of ML applications for different medical image processing.The proposed method improves the accuracy,precision,and training rate by 13.19%,10.69%,and 11.06%,respectively,compared to other models for the selected dataset.The mean error and selection time is also reduced by 12.56%and 13.56%,respectively,compared to the same models and dataset.

Revolutionizing diabetic retinopathy screening and management:The role of artificial intelligence and machine learning

Diabetic retinopathy(DR)remains a leading cause of vision impairment and blindness among individuals with diabetes,necessitating innovative approaches to screening and management.This editorial explores the transformative potential of artificial intelligence(AI)and machine learning(ML)in revolutionizing DR care.AI and ML technologies have demonstrated remarkable advancements in enhancing the accuracy,efficiency,and accessibility of DR screening,helping to overcome barriers to early detection.These technologies leverage vast datasets to identify patterns and predict disease progression with unprecedented precision,enabling clinicians to make more informed decisions.Furthermore,AI-driven solutions hold promise in personalizing management strategies for DR,incorpo-rating predictive analytics to tailor interventions and optimize treatment path-ways.By automating routine tasks,AI can reduce the burden on healthcare providers,allowing for a more focused allocation of resources towards complex patient care.This review aims to evaluate the current advancements and applic-ations of AI and ML in DR screening,and to discuss the potential of these techno-logies in developing personalized management strategies,ultimately aiming to improve patient outcomes and reduce the global burden of DR.The integration of AI and ML in DR care represents a paradigm shift,offering a glimpse into the future of ophthalmic healthcare.

Machine learning applications in healthcare clinical practice and research

Machine learning(ML)is a type of artificial intelligence that assists computers in the acquisition of knowledge through data analysis,thus creating machines that can complete tasks otherwise requiring human intelligence.Among its various applications,it has proven groundbreaking in healthcare as well,both in clinical practice and research.In this editorial,we succinctly introduce ML applications and present a study,featured in the latest issue of the World Journal of Clinical Cases.The authors of this study conducted an analysis using both multiple linear regression(MLR)and ML methods to investigate the significant factors that may impact the estimated glomerular filtration rate in healthy women with and without non-alcoholic fatty liver disease(NAFLD).Their results implicated age as the most important determining factor in both groups,followed by lactic dehydrogenase,uric acid,forced expiratory volume in one second,and albumin.In addition,for the NAFLD-group,the 5th and 6th most important impact factors were thyroid-stimulating hormone and systolic blood pressure,as compared to plasma calcium and body fat for the NAFLD+group.However,the study's distinctive contribution lies in its adoption of ML methodologies,showcasing their superiority over traditional statistical approaches(herein MLR),thereby highlighting the potential of ML to represent an invaluable advanced adjunct tool in clinical practice and research.

Machine learning in solid organ transplantation:Charting the evolving landscape

BACKGROUND Machine learning(ML),a major branch of artificial intelligence,has not only demonstrated the potential to significantly improve numerous sectors of healthcare but has also made significant contributions to the field of solid organ transplantation.ML provides revolutionary opportunities in areas such as donorrecipient matching,post-transplant monitoring,and patient care by automatically analyzing large amounts of data,identifying patterns,and forecasting outcomes.AIM To conduct a comprehensive bibliometric analysis of publications on the use of ML in transplantation to understand current research trends and their implications.METHODS On July 18,a thorough search strategy was used with the Web of Science database.ML and transplantation-related keywords were utilized.With the aid of the VOS viewer application,the identified articles were subjected to bibliometric variable analysis in order to determine publication counts,citation counts,contributing countries,and institutions,among other factors.RESULTS Of the 529 articles that were first identified,427 were deemed relevant for bibliometric analysis.A surge in publications was observed over the last four years,especially after 2018,signifying growing interest in this area.With 209 publications,the United States emerged as the top contributor.Notably,the"Journal of Heart and Lung Transplantation"and the"American Journal of Transplantation"emerged as the leading journals,publishing the highest number of relevant articles.Frequent keyword searches revealed that patient survival,mortality,outcomes,allocation,and risk assessment were significant themes of focus.CONCLUSION The growing body of pertinent publications highlights ML's growing presence in the field of solid organ transplantation.This bibliometric analysis highlights the growing importance of ML in transplant research and highlights its exciting potential to change medical practices and enhance patient outcomes.Encouraging collaboration between significant contributors can potentially fast-track advancements in this interdisciplinary domain.

基于参数优化VMD和改进LSSVM的道岔故障诊断方法

为了解决道岔设备智能故障诊断中特征指标难以提取以及模型训练时间较长的问题,以ZDJ9型转辙机带动的道岔设备为研究对象,以转辙机功率曲线为数据基础,提出一种基于参数优化变分模态分解(Variational Mode Decomposition,VMD)和改进最小二乘支持向量机(Least Squares Support Vector Machines,LSSVM)的道岔故障诊断方法。首先,采用鲸鱼优化算法(Whale Optimization Algorithm,WOA)优化VMD参数,得到模态(Intrinsic Mode Functions,IMF)分量个数和惩罚因子的最优参数组合。其次,计算IMF分量与功率曲线的相关系数,优选相关性较大的前3阶IMF分量,并计算功率谱熵、模糊熵及包络熵值,建立多特征融合样本数据库。最后,针对麻雀搜索算法(Sparrow Search Algorithm,SSA)易陷入局部最优的问题,通过改进Tent混沌映射初始化策略随机生成种群,正余弦算法(Sine Cosine Algorithm,SCA)更新追随者的位置,并采用改进SSA优化LSSVM算法的惩罚因子和核函数方差,构建基于TSSSA-LSSVM的道岔故障诊断模型。实验结果表明:所提道岔故障诊断方法是可行的,采用多特征融合能够更加全面地提取道岔典型故障特征,反映道岔的真实运行状态,提高了故障诊断准确率,而且较TSSSA-SVM,PSO-LSSVM,GWO-LSSVM以及SSA-LSSVM等方法具有较高的故障诊断准确率、召回率以及较低的漏报率,减少了模型训练时间,完全满足现场道岔故障导向安全的原则,具有更好的故障诊断性能,对现场道岔设备的故障维修具有一定的指导意义。

基于DBO-LSSVM的空气质量指数预测

针对当下空气质量指数预测的模型精度不高的问题,提出一种基于蜣螂优化(DBO)算法,优化最小二乘支持向量机(LSSVM)的空气质量指数预测模型。该模型利用蜣螂优化算法对最小二乘支持向量机的两项参数进行寻优,提高预测速度和精度。并与传统最小二乘支持向量机、灰狼优化最小二乘支持向量机模型进行比对,通过实验仿真结果表明,蜣螂优化算法优化最小二乘支持向量机预测模型的均方误差、平均绝对误差及决定系数均为最优值,可以为空气质量指数预测提供更准确的支持。

基于改进LSSVM算法的柔性飞机起落架智能半主动控制技术

提出了基于改进LSSVM算法的柔性飞机起落架智能半主动控制技术。充分考虑柔性飞机结构振动模态,构建飞机起落架智能半主动控制力学模型。根据半主动控制起落架结构,采用剪枝算法构造最小二乘支持向量机优化函数,使控制过程具有稀疏性。计算双气室缓冲器的气体弹力、油孔液压阻尼力和轮胎压力,分析飞机落下、滑跑在动力学模型中的非线性动力学特征。构造起落架二次型性能指标函数,用线性二次型调节器设计起落架最优控制结构,导出最优控制律。由实验结果可知:该技术在缓冲距离为0.25 m时功量达到最大为0.9×10^(5)N,与实际着陆功量控制效果一致;最大位移为0.47 m,仅与实际存在最大为0.01 m的误差,使飞机在平衡位置减少振动响应,保持飞机起落稳定。

基于IPOA-LSSVM模型的高压直流输电线路故障定位

故障定位在长距离高压直流输电系统中起着至关重要的作用.针对线路衰减系数计算不准和二次波头难以捕捉的问题,提出了一种改进鹈鹕优化算法(IPOA)优化最小二乘支持向量(LSSVM)的故障定位模型.根据行波衰减原理,推导故障距离和线路两端线模分量模极大值比的计算公式,发现二者具有非线性关系.使用LSSVM泛化二者之间的关系,将改进后的POA算法对LSSVM的关键参数进行寻优,建立IPOA-LSSVM故障定位模型.通过在两端采集故障信号,对其进行小波变换得到首波头幅值比作为模型的输入量,故障距离作为输出量进行仿真验证.仿真结果表明,该模型不受过渡电阻和故障类型的影响,能够可靠准确地定位.

基于IDBO-LSSVM的输电线路覆冰厚度预测模型

针对输电线路受多种气象因素影响导致覆冰厚度预测精度低的问题,提出基于改进蜣螂优化(improved dung beetle optimizer,IDBO)算法优化最小二乘支持向量机(least square support vector machine,LSSVM)的输电线路覆冰厚度预测模型。首先,使用皮尔逊相关系数(Pearson correlation coefficient,PCC)计算输电线路覆冰厚度与不同气象因素之间的相关性,选择具有高相关性的气象因素以确定输入变量;其次,通过引入Halton序列、Levy飞行策略和T分布扰动来改进蜣螂优化(dung beetle optimizer,DBO)算法;最后,使用IDBO算法寻优LSSVM参数:调节因子、核函数宽度,提高模型预测精度。以某地输电线路历史监测数据为样本,将IDBO-LSSVM的输电线路预测结果与其他7种预测模型进行比较,发现平均绝对误差分别降低了约27%、36%、25%、23%、24%、44%和39%。该研究证实了基于IDBO-LSSVM的输电线路覆冰厚度预测模型可以有效提高预测精度。

基于KPCA-LSSVM的回采工作面瓦斯涌出量的预测

为了提高瓦斯涌出量预测精度,针对瓦斯涌出量影响因素具有线性重叠、高维非线性等问题,提出使用核主成分分析法(KPCA)对影响因素进行非线性降维。选取沈阳某矿30组样本数据,以前24组数据作为训练集,后6组数据作为测试集,将确定后的核主成分作为最小二乘支持向量机(LSSVM)的输入变量,建立KPCA-LSSVM预测模型,将预测结果与PCA-LSSVM、LSSVM、多元非线性回归、KPCA-BP神经网络、PCA-BP神经网络以及BP神经网络预测结果进行对比。以最大相对误差绝对值作为模型预测精度的评价指标。研究结果表明:当选取前4个核主成分时,即达到模型训练要求。KPCA-LSSVM模型的预测最大相对误差绝对值为5.89%,预测精度均优于其他6种对比模型。研究结果可为实现瓦斯涌出量高精度预测提供参考。

基于AOA-LSSVM模型的枢纽城市物流需求量预测

传统的LSSVM难以全面反映物流需求的变化规律,会导致预测效果不佳。首先利用灰色关联分析(GRA)得到物流需求的主要影响因素;将主要影响因素作为LSSVM的输入变量,构建物流需求预测模型;通过阿基米德算法(AOA)对最小二乘支持向量机的正则化参数(γ)和核参数(σ)进行迭代寻优,以减少参数选择的盲目性;构建AOA算法优化最小二乘支持向量机(LSSVM)的智能预测模型AOA-LSSVM,经过验证该模型可以提高预测精度。运用AOA-LSSVM模型对西部陆海新通道的重要枢纽城市——重庆、成都、贵阳和南宁的物流需求进行实证分析,结果表明:该模型与LSSVM模型相比取得较高的预测精度,其均方根误差、平均绝对误差、以及异方差调整的均方根误差、异方差调整的平均绝对误差分别降低了1946.4,1206.1,0.0284,0.0397。

基于VMD-BOA-LSSVM-AdaBoost的短期风电功率预测

针对风电信号具有间歇性、非线性、波动性、非平稳性和不确定性等特征,建立一种基于变分模态分解(VMD)和蝴蝶优化算法(BOA)优化最小二乘支持向量机(LSSVM)的风电功率短期预测模型,为提高预测精度,引入自适应校正算法(AdaBoost)。首先,利用变分模态分解将原始功率信号数据分解多个子序列。其次,利用蝴蝶优化算法优化最小二乘支持向量机组合预测模型对每个子序列进行预测。最后通过自适应校正算法将多个分量预测值重构得到最终的预测值,结合西北某一风电场提供的风电功率数据为例验证模型的有效性。结果验证了建立的组合预测模型能够较好地对短期风电功率进行预测,并具有较好的预测精度。

Application of Least Square Support Vector Machine (LSSVM) for Determination of Evaporation Losses in Reservoirs

This article adopts Least Square Support Vector Machine (LSSVM) for prediction of Evaporation Losses (EL) in reservoirs. LSSVM is firmly based on the theory of statistical learning, uses regression technique. The input of LSSVM model is Mean air temperature (T) (?C), Average wind speed (WS)(m/sec), Sunshine hours (SH)(hrs/day), and Mean relative humidity(RH)(%). LSSVM has been used to compute error barn of predicted data. An equation has been developed for the determination of EL. Sensitivity analysis has been also performed to investigate the importance of each of the input parameters. A comparative study has been presented between LSSVM and artificial neural network (ANN) models. This study shows that LSSVM is a powerful tool for determination EL in reservoirs.

基于ISSA-HKLSSVM的浮选精矿品位预测方法

针对浮选过程变量滞后、耦合特征及建模样本数量少所导致精矿品位难以准确预测的问题,提出了一种基于改进麻雀搜索算法(Improved Sparrow Search Algorithm,ISSA)优化混核最小二乘支持向量机(Hybrid Kernel Least Squares Support Vector Machine,HKLSSVM)的浮选过程精矿品位预测方法.首先采集浮选现场载流X荧光品位分析仪数据作为建模变量并进行预处理,建立基于最小二乘支持向量机(Least Squares Support Vector Machine,LSSVM)的预测模型,以此构建新型混合核函数,将输入空间映射至高维特征空间,再引入改进麻雀搜索算法对模型参数进行优化,提出基于ISSA-HKLSSVM方法实现精矿品位预测,最后开发基于LabVIEW的浮选精矿品位预测系统对本文提出方法实际验证.实验结果表明,本文提出方法对于浮选过程小样本建模具有良好拟合能力,相比现有方法提高了预测准确率,可实现精矿品位的准确在线预测,为浮选过程的智能调控提供实时可靠的精矿品位反馈信息.

短期风电功率CEEMDAN-SMA-LSSVM预测模型研究

为了提高风力发电功率预测的准确性,建立了基于CEEMDAN分解的SMA算法优化LSSVM的短期风电功率组合预测模型。首先,采用完全集合经验模态分解(CEEMDAN)对原始风电功率数据进行分解与重构。随后,为了进一步优化最小二乘向量支持机模型(LSSVM)的参数,引入了黏菌算法(SMA)优化,通过调整惩罚参数和核参数来提高模型性能,最后,构建多种对比模型对比分析表明CEEMDAN-SMA-LSSVM模型预测精度最高,预测结果更接近真实值。研究可用于风电场短期风电功率预测使用。

Analysis of Ammonia Nitrogen Content in Water Based on Weighted Least Squares Support Vector Machine (WLSSVM) Algorithm

Determination of ammonia nitrogen content in water is the basic item of the environmental water pollution, and is the key index to evaluate the water quality. This article designs a water quality monitoring system based on the on-line automatic ammonia nitrogen monitoring system, and establishes a forecasting model based on the weighted least squares support vector machine algorithm. The weighted least squares support vector machine algorithm increases the weight parameter setting, improves the speed and accuracy of prediction learning, and improves the robustness. In this article, a comparison between neural network model and weighted least square support vector machine model is made, which shows that the weighted least squares support vector machine model has better prediction accuracy.

基于ANFIS-LSSVM的计算颜色恒常性算法研究

计算颜色恒常性是指消除场景光源的影响从而再现物体真实颜色的能力。目前,深度神经网络的应用使颜色恒常性精度显著提高,但大多数深度学习算法训练时间长、计算复杂度高,且需要大量的训练样本。针对此问题,提出了一种结合自适应神经模糊推理系统(ANFIS)和最小二乘支持向量机(LSSVM)的简单有效的方法。该方法分为训练和预测两个阶段:在训练阶段,首先提取图像特征分别训练ANFIS、LSSVM两种初始光源估计模型,接着利用核函数变换将两种模型融合,然后利用预留训练样本进一步训练得到多元线性回归光源估计模型;在预测阶段,提取测试图像特征后,直接由训练所得模型预测得到该测试图像最终的场景光源颜色值。实验结果表明,与深度学习方法相比,本文所提方法计算复杂度较低,即使在小训练样本中也能有很好的光源估计性能。

基于CNN-LSSVM的电力系统虚假数据攻击检测

新型信息物理电力系统是实现双碳目标的关键环节,但针对状态估计的新型虚假数据攻击可以欺骗现有安全检测机制,给电力系统安全运行带来巨大挑战。为检测状态估计中虚假数据,以电网交流模型为研究对象分析恶意攻击的欺骗特性,结合CNN(卷积神经网络)提取数据的空间特征优势和LSSVM(最小二乘支持向量机)的数据分类能力,构建了基于CNN-LSSVM的攻击检测模型。基于IEEE 14总线电力系统数据验证了所提出的CNN-LSSVM检测模型的有效性,其检测准确率达到94.6%。