A Deep Learning-Based Computational Algorithm for Identifying Damage Load Condition: An Artificial Intelligence Inverse Problem Solution for Failure Analysis

In this work,we have developed a novel machine(deep)learning computational framework to determine and identify damage loading parameters(conditions)for structures and materials based on the permanent or residual plastic deformation distribution or damage state of the structure.We have shown that the developed machine learning algorithm can accurately and(practically)uniquely identify both prior static as well as impact loading conditions in an inverse manner,based on the residual plastic strain and plastic deformation as forensic signatures.The paper presents the detailed machine learning algorithm,data acquisition and learning processes,and validation/verification examples.This development may have significant impacts on forensic material analysis and structure failure analysis,and it provides a powerful tool for material and structure forensic diagnosis,determination,and identification of damage loading conditions in accidental failure events,such as car crashes and infrastructure or building structure collapses.

Bayesian machine learning-based method for prediction of slope failure time

The data-driven phenomenological models based on deformation measurements have been widely utilized to predict the slope failure time(SFT).The observational and model uncertainties could lead the predicted SFT calculated from the phenomenological models to deviate from the actual SFT.Currently,very limited study has been conducted on how to evaluate the effect of such uncertainties on SFT prediction.In this paper,a comprehensive slope failure database was compiled.A Bayesian machine learning(BML)-based method was developed to learn the model and observational uncertainties involved in SFT prediction,through which the probabilistic distribution of the SFT can be obtained.This method was illustrated in detail with an example.Verification studies show that the BML-based method is superior to the traditional inverse velocity method(INVM)and the maximum likelihood method for predicting SFT.The proposed method in this study provides an effective tool for SFT prediction.

Flap failure prediction in microvascular tissue reconstruction using machine learning algorithms

BACKGROUND Microvascular tissue reconstruction is a well-established,commonly used technique for a wide variety of the tissue defects.However,flap failure is associated with an additional hospital stay,medical cost burden,and mental stress.Therefore,understanding of the risk factors associated with this event is of utmost importance.AIM To develop machine learning-based predictive models for flap failure to identify the potential factors and screen out high-risk patients.METHODS Using the data set of 946 consecutive patients,who underwent microvascular tissue reconstruction of free flap reconstruction for head and neck,breast,back,and extremity,we established three machine learning models including random forest classifier,support vector machine,and gradient boosting.Model performances were evaluated by the indicators such as area under the curve of receiver operating characteristic curve,accuracy,precision,recall,and F1 score.A multivariable regression analysis was performed for the most critical variables in the random forest model.RESULTS Post-surgery,the flap failure event occurred in 34 patients(3.6%).The machine learning models based on various preoperative and intraoperative variables were successfully developed.Among them,the random forest classifier reached the best performance in receiver operating characteristic curve,with an area under the curve score of 0.770 in the test set.The top 10 variables in the random forest were age,body mass index,ischemia time,smoking,diabetes,experience,prior chemotherapy,hypertension,insulin,and obesity.Interestingly,only age,body mass index, and ischemic time were statistically associated with the outcomes.CONCLUSIONMachine learning-based algorithms, especially the random forest classifier, were very important incategorizing patients at high risk of flap failure. The occurrence of flap failure was a multifactordrivenevent and was identified with numerous factors that warrant further investigation.Importantly, the successful application of machine learning models may help the clinician indecision-making, understanding the underlying pathologic mechanisms of the disease, andimproving the long-term outcome of patients.

Machine Learning and Synthetic Minority Oversampling Techniques for Imbalanced Data: Improving Machine Failure Prediction

Prediction of machine failure is challenging as the dataset is often imbalanced with a low failure rate.The common approach to han-dle classification involving imbalanced data is to balance the data using a sampling approach such as random undersampling,random oversampling,or Synthetic Minority Oversampling Technique(SMOTE)algorithms.This paper compared the classification performance of three popular classifiers(Logistic Regression,Gaussian Naïve Bayes,and Support Vector Machine)in predicting machine failure in the Oil and Gas industry.The original machine failure dataset consists of 20,473 hourly data and is imbalanced with 19945(97%)‘non-failure’and 528(3%)‘failure data’.The three independent variables to predict machine failure were pressure indicator,flow indicator,and level indicator.The accuracy of the classifiers is very high and close to 100%,but the sensitivity of all classifiers using the original dataset was close to zero.The performance of the three classifiers was then evaluated for data with different imbalance rates(10%to 50%)generated from the original data using SMOTE,SMOTE-Support Vector Machine(SMOTE-SVM)and SMOTE-Edited Nearest Neighbour(SMOTE-ENN).The classifiers were evaluated based on improvement in sensitivity and F-measure.Results showed that the sensitivity of all classifiers increases as the imbalance rate increases.SVM with radial basis function(RBF)kernel has the highest sensitivity when data is balanced(50:50)using SMOTE(Sensitivitytest=0.5686,Ftest=0.6927)compared to Naïve Bayes(Sensitivitytest=0.4033,Ftest=0.6218)and Logistic Regression(Sensitivitytest=0.4194,Ftest=0.621).Overall,the Gaussian Naïve Bayes model consistently improves sensitivity and F-measure as the imbalance ratio increases,but the sensitivity is below 50%.The classifiers performed better when data was balanced using SMOTE-SVM compared to SMOTE and SMOTE-ENN.

A Self-Learning Data-Driven Development of Failure Criteria of Unknown Anisotropic Ductile Materials with Deep Learning Neural Network

This paper first proposes a new self-learning data-driven methodology that can develop the failure criteria of unknown anisotropic ductile materials from the minimal number of experimental tests.Establishing failure criteria of anisotropic ductile materials requires time-consuming tests and manual data evaluation.The proposed method can overcome such practical challenges.The methodology is formalized by combining four ideas:1)The deep learning neural network(DLNN)-based material constitutive model,2)Self-learning inverse finite element(SELIFE)simulation,3)Algorithmic identification of failure points from the selflearned stress-strain curves and 4)Derivation of the failure criteria through symbolic regression of the genetic programming.Stress update and the algorithmic tangent operator were formulated in terms of DLNN parameters for nonlinear finite element analysis.Then,the SELIFE simulation algorithm gradually makes the DLNN model learn highly complex multi-axial stress and strain relationships,being guided by the experimental boundary measurements.Following the failure point identification,a self-learning data-driven failure criteria are eventually developed with the help of a reliable symbolic regression algorithm.The methodology and the self-learning data-driven failure criteria were verified by comparing with a reference failure criteria and simulating with different materials orientations,respectively.

Machine Learning and Artificial Neural Network for Predicting Heart Failure Risk

Heart failure is now widely spread throughout the world.Heart disease affects approximately 48%of the population.It is too expensive and also difficult to cure the disease.This research paper represents machine learning models to predict heart failure.The fundamental concept is to compare the correctness of various Machine Learning(ML)algorithms and boost algorithms to improve models’accuracy for prediction.Some supervised algorithms like K-Nearest Neighbor(KNN),Support Vector Machine(SVM),Decision Trees(DT),Random Forest(RF),Logistic Regression(LR)are considered to achieve the best results.Some boosting algorithms like Extreme Gradient Boosting(XGBoost)and Cat-Boost are also used to improve the prediction using Artificial Neural Networks(ANN).This research also focuses on data visualization to identify patterns,trends,and outliers in a massive data set.Python and Scikit-learns are used for ML.Tensor Flow and Keras,along with Python,are used for ANN model train-ing.The DT and RF algorithms achieved the highest accuracy of 95%among the classifiers.Meanwhile,KNN obtained a second height accuracy of 93.33%.XGBoost had a gratified accuracy of 91.67%,SVM,CATBoost,and ANN had an accuracy of 90%,and LR had 88.33%accuracy.

基于改进FMEA的E-learning系统质量失效模式风险排序

针对传统失效模式与效应分析(FMEA)方法的不足,构建结合区间二元语义和ELECTRE法的改进FMEA模型,以解决不确定语言环境下失效模式的风险排序问题。研究表明,该模型可以有效地将模糊语言表达转化为二元语义量化数据进行计算;通过对专家成员和风险因素设置权重,有效减少了极端偏见等对结果的影响;通过多准则决策ELECTRE方法对数据项间的越级关系分析,增强了模型的灵活性和适用性,提高了排序结果的准确性。研究结果表明,E-Learning系统质量失效模式风险指数最高的是效率性,企业在产品设计和质量改进时,应对与效率性相关的内容重点关注和优先考虑。

Tunnel face reliability analysis using active learning Kriging model——Case of a two-layer soils

This paper is devoted to the probabilistic stability analysis of a tunnel face excavated in a two-layer soil. The interface of the soil layers is assumed to be positioned above the tunnel roof. In the framework of limit analysis, a rotational failure mechanism is adopted to describe the face failure considering different shear strength parameters in the two layers. The surrogate Kriging model is introduced to replace the actual performance function to perform a Monte Carlo simulation. An active learning function is used to train the Kriging model which can ensure an efficient tunnel face failure probability prediction without loss of accuracy. The deterministic stability analysis is given to validate the proposed tunnel face failure model. Subsequently, the number of initial sampling points, the correlation coefficient, the distribution type and the coefficient of variability of random variables are discussed to show their influences on the failure probability. The proposed approach is an advisable alternative for the tunnel face stability assessment and can provide guidance for tunnel design.

基于节点兴趣和Q-learning的P2P网络搜索机制

将智能手机设备加入基于非结构化P2P网络的资源共享系统中能够满足人们对资源共享的多样化、便利性、高频性、实时性、高效性等要求,但是该系统网络规模的扩张和网络节点互异性的加大,必将导致系统资源搜索效率的降低、冗余信息的剧增以及网络更加不稳定。为了解决这些问题,文中设计了一种改进的基于节点兴趣和Q-learning的资源搜索机制。首先将节点根据兴趣相似度进行兴趣聚类,划分兴趣集,然后根据兴趣集中节点的能力值构建兴趣树,该结构避免了消息环路的产生,极大地降低了冗余信息;在资源搜索中,兴趣树内采用洪泛算法转发消息,兴趣树之间采用基于Q-learning的消息转发机制,不断强化最可能获取目标资源的路径,查询消息优先在这些路径上传播。另外,针对“热点”资源问题,设计了自适应热点资源索引机制,减少了重复路径搜索,进一步减少了冗余消息量;针对节点失效的问题,给出了根节点冗余机制和捎带检测的策略方法,分别解决了根节点失效和普通节点失效导致的兴趣树的不完整性问题,分析表明该方法能够减少消息冗余量。仿真实验结果表明,与GBI-BI算法和Interest CN算法相比,所提搜索算法能够提高命中率,缩短响应时间,减少冗余信息,具有较好的综合性能,最终解决了由于智能手机设备加入P2P网络导致的资源搜索效率下降、网络流量开销大的问题。

A Study of Pragmatic Failures in Cross-Cultural Communication

This paper focuses on pragmatic failures in cross-cultural communication and explores the difficult meanings in cross-cultural pragmatics. Through exploring the differences in address, greeting, politeness and other cross-cultural aspects, the author explains the cross-cultural basis for pragmatics. The author first explains certain concepts, including culture, pragmatics, pragmatic failures and cross-cultural communication, and then illustrates some pragmatic failures in cross-cultural communication and discusses the causes of these failures. Finally, she gives some suggestions on improving competence in cross-cultural communication. This thesis is intended to remind English learners of the importance of learning cultures of English-speaking countries and facilitate cross-cultural communication.

Time series prediction of reservoir bank landslide failure probability considering the spatial variability of soil properties

Historically,landslides have been the primary type of geological disaster worldwide.Generally,the stability of reservoir banks is primarily affected by rainfall and reservoir water level fluctuations.Moreover,the stability of reservoir banks changes with the long-term dynamics of external disastercausing factors.Thus,assessing the time-varying reliability of reservoir landslides remains a challenge.In this paper,a machine learning(ML)based approach is proposed to analyze the long-term reliability of reservoir bank landslides in spatially variable soils through time series prediction.This study systematically investigated the prediction performances of three ML algorithms,i.e.multilayer perceptron(MLP),convolutional neural network(CNN),and long short-term memory(LSTM).Additionally,the effects of the data quantity and data ratio on the predictive power of deep learning models are considered.The results show that all three ML models can accurately depict the changes in the time-varying failure probability of reservoir landslides.The CNN model outperforms both the MLP and LSTM models in predicting the failure probability.Furthermore,selecting the right data ratio can improve the prediction accuracy of the failure probability obtained by ML models.

Predicting depression in patients with heart failure based on a stacking model

BACKGROUND There is a lack of literature discussing the utilization of the stacking ensemble algorithm for predicting depression in patients with heart failure(HF).AIM To create a stacking model for predicting depression in patients with HF.METHODS This study analyzed data on 1084 HF patients from the National Health and Nutrition Examination Survey database spanning from 2005 to 2018.Through univariate analysis and the use of an artificial neural network algorithm,predictors significantly linked to depression were identified.These predictors were utilized to create a stacking model employing tree-based learners.The performances of both the individual models and the stacking model were assessed by using the test dataset.Furthermore,the SHapley additive exPlanations(SHAP)model was applied to interpret the stacking model.RESULTS The models included five predictors.Among these models,the stacking model demonstrated the highest performance,achieving an area under the curve of 0.77(95%CI:0.71-0.84),a sensitivity of 0.71,and a specificity of 0.68.The calibration curve supported the reliability of the models,and decision curve analysis confirmed their clinical value.The SHAP plot demonstrated that age had the most significant impact on the stacking model's output.CONCLUSION The stacking model demonstrated strong predictive performance.Clinicians can utilize this model to identify highrisk depression patients with HF,thus enabling early provision of psychological interventions.

改进的GAN和迁移学习的轴承故障诊断方法

针对实际设备运行中轴承故障样本往往比较匮乏,传统的人工智能算法越来越难以满足实际情况故障诊断需要的问题,提出了一种改进的生成对抗神经网络模型,并结合迁移学习提出了一种智能故障诊断方法。该方法将机械故障时所采集的原始数据与大量源域数据通过生成对抗网络中得到大量与原始数据相似的新样本数据,然后从新样本数据中学习特征优化神经网络的参数,并通过样本的分布相应的调节神经网络的结构,最后,将部分原始故障数据输入已训练好的神经网络,得到诊断结果。实验结果表明,所提方法较传统的深度学习和迁移学习在诊断准确率上分别提高了28.10%和24.42%,能够为实际制造中轴承故障诊断任务提供可行的解决方案。

基于格拉姆角场和PCNN-GRU的换相失败诊断方法

高压直流输电作为一种高效的电力传输技术,其运行中的换相失败会导致直流电流迅速增加、直流电压急剧下降,对电网的安全稳定运行造成重大影响。针对换相失败,提出一种结合格拉姆角场(Gramian angular field,GAF)与并行卷积神经网络–门控循环单元(Parallel convolutional neural network-gated recurrent unit,PCNN-GRU)的换相失败诊断方法。利用GAF将一维时间序列信号转换为二维图像特征图,保留信号的时序信息。再利用PCNN-GRU模型的卷积神经网络的特征提取能力和门控循环单元的时序特征处理能力,使模型学习更多的故障特征,提高模型的诊断性能。以永富直流输电系统为对象,实验结果表明该方法诊断精度为99.33%,有较强的多特征提取能力和时序特性分析能力,诊断性能强,响应及识别换相失败快速。

电动机故障诊断联邦学习模型研究及技术应用

文中提出了一种基于深度学习以及联邦学习的电动机故障诊断模型。使用Transformer模型对电动机的运行数据进行分析以及故障诊断分类,在此基础上使用FedProx联邦学习算法,在多个客户端上使用不同的数据训练模型,并将训练后的模型上传到中央服务器进行聚合,使用聚合后的模型对设备进行故障诊断。实验结果表明,所提出的模型具有良好的性能,对数据的故障分类准确率满足电动机故障诊断的要求,同时联邦学习的方法有助于模型获得更多的数据特征,使得模型可以更好地进行故障诊断,同时对保护数据隐私也有一定作用。

LEARNS模式在心力衰竭患者门诊随访健康教育中的应用

目的:分析LEARNS模式在心衰患者门诊随访健康教育中的应用效果。方法:2019年6月至2020年10月,采用随机数字表法将100例北京市某三级甲等医院门诊随访的心衰患者随机分为干预组和对照组,各50例,进行为期3个月的干预,对照组接受常规心衰门诊随访健康教育,干预组接受基于LEARNS模式的健康教育。在干预前、干预3个月后分别对两组患者进行Atlanta心衰知识问卷、欧洲心衰自我护理行为量表和心衰疾病相关指标的评价。结果:干预3个月后,干预组患者心衰相关知识、自我护理行为、B型利钠肽水平较对照组改善明显(P<0.05),NYHA心功能分级Ⅰ级所占比例高于对照组(P<0.05)。结论:基于LEARNS模式的健康教育可改善心衰患者的疾病相关知识、自我护理行为情况,以及NYHA心功能分级和B型利钠肽水平。

深度学习在心力衰竭检测中的应用综述

随着生物医学技术的发展,利用生物信号进行心力衰竭的早期诊断已成为提高患者生存率和降低治疗成本的关键策略。在此背景下,深度学习技术的迅猛发展为心力衰竭检测开辟了新路径。系统地综述了深度学习在心力衰竭检测中的最新进展和应用。概述了心力衰竭检测涉及的主要生物医学信号和公开数据集。详细分析了深度学习在心力衰竭诊断领域的应用及其发展,特别是对卷积神经网络和长短期记忆网络处理心电图、心率变异性、心音等关键生物医学信号的能力进行了深入分析,总结了这些技术的优势、局限性,并对各类模型性能进行了比较。探讨了通过融合多种人工智能技术所构建的混合模型在提升检测精度和模型泛化能力方面的潜力,以及如何利用模型的可解释性来增加检测过程的透明度,提升医生的信任度。最后总结了当前研究存在的不足,并对未来研究方向提出展望,强调了跨学科合作在推动心力衰竭检测技术进步中的重要性。

面向异构社交网络的空-频域自适应图神经网络

传统GNN基于同构性假设对近邻节点实现低通滤波功能完成邻域相似信息的聚合嵌入。但在异构图中分属不同类别的节点彼此多建立联系,而相同类别的节点在图拓扑位置上距离较远。这一特点给注重近端邻域信息聚合的传统GNN带来“远端节点信息聚合缺失”与“同构性假设失灵”的问题。因此设计融合空域与频域自适应嵌入机制的异构图神经网络(DA-HGNN)以解决上述问题。针对问题一,设计“远端空域嵌入模块”,旨在通过高阶随机游走迁移概率筛选并聚合远端相似节点,补充“消息传递的跨邻域自适应性”;针对问题二,设计“近端频域嵌入模块”,构建滤波器分离节点高频与低频信号,并设计频域导向型注意力机制对上述信息进行频域偏好的自适应融合,从而减少“同构性假设失灵”所引入的噪声。在四个公开异构图数据集中取得最优实验结果,准确率上平均提高6.41个百分点。在灵敏度分析和消融实验中阐述了超参数的选择机制和各模块的实际性能,并验证了在异构网络中“节点结构相似性”“节点属性向量相似性”以及“节点同构性”三者之间仍呈现正相关关系这一结论。在异构真实数据集中验证了欺诈检测效果,AUC指标提升4.4个百分点。

基于CLD-COA-ELM的光伏阵列故障诊断方法研究

为提升光伏阵列故障诊断的准确率,提出一种基于改进长鼻浣熊优化算法优化极限学习机的光伏阵列故障诊断方法。首先,分析阵列中光伏组件在发生故障时的输出特性,选择合适的故障特征;其次,针对极限学习机在光伏阵列故障分类时初始权值和阈值的随机性问题,采用长鼻浣熊优化算法求解最优的初始权重和阈值;进一步地,针对长鼻浣熊算法初始参数的随机性和全局搜索能力的局限性问题,通过Circle混沌映射、莱维飞行和动态折射反向学习对该算法进行优化,提高寻优精度和速度;最后,结合光伏阵列故障实验数据,验证故障诊断模型的分类效果。结果表明,对于训练集和测试集数据,该诊断模型提高了故障分类精度,诊断率分别达到100%和98.33%,优于传统极限学习机、BP神经网络、支持向量机和卷积神经网络故障诊断的准确率。

Application of Radial Basis Function Network in Sensor Failure Detection

Aim To detect sensor failure in control system using a single sensor signal. Methods A neural predictor was designed based on a radial basis function network(RBFN), and the neural predictor learned the sensor signal on line with a hybrid algorithm composed of n means clustering and Kalman filter and then gave the estimation of the sensor signal at the next step. If the difference between the estimation and the actural values of the sensor signal exceeded a threshold, the sensor could be declared to have a failure. The choice of the failure detection threshold depends on the noise variance and the possible prediction error of neural predictor. Results and Conclusion\ The computer simulation results show the proposed method can detect sensor failure correctly for a gyro in an automotive engine.