A Self-Adapting and Efficient Dandelion Algorithm and Its Application to Feature Selection for Credit Card Fraud Detection

A dandelion algorithm(DA) is a recently developed intelligent optimization algorithm for function optimization problems. Many of its parameters need to be set by experience in DA,which might not be appropriate for all optimization problems. A self-adapting and efficient dandelion algorithm is proposed in this work to lower the number of DA's parameters and simplify DA's structure. Only the normal sowing operator is retained;while the other operators are discarded. An adaptive seeding radius strategy is designed for the core dandelion. The results show that the proposed algorithm achieves better performance on the standard test functions with less time consumption than its competitive peers. In addition, the proposed algorithm is applied to feature selection for credit card fraud detection(CCFD), and the results indicate that it can obtain higher classification and detection performance than the-state-of-the-art methods.

A Credit Card Fraud Model Prediction Method Based on Penalty Factor Optimization AWTadaboost

With the popularity of online payment, how to perform creditcard fraud detection more accurately has also become a hot issue. And withthe emergence of the adaptive boosting algorithm (Adaboost), credit cardfraud detection has started to use this method in large numbers, but thetraditional Adaboost is prone to overfitting in the presence of noisy samples.Therefore, in order to alleviate this phenomenon, this paper proposes a newidea: using the number of consecutive sample misclassifications to determinethe noisy samples, while constructing a penalty factor to reconstruct thesample weight assignment. Firstly, the theoretical analysis shows that thetraditional Adaboost method is overfitting in a noisy training set, which leadsto the degradation of classification accuracy. To this end, the penalty factorconstructed by the number of consecutive misclassifications of samples isused to reconstruct the sample weight assignment to prevent the classifierfrom over-focusing on noisy samples, and its reasonableness is demonstrated.Then, by comparing the penalty strength of the three different penalty factorsproposed in this paper, a more reasonable penalty factor is selected.Meanwhile, in order to make the constructed model more in line with theactual requirements on training time consumption, the Adaboost algorithmwith adaptive weight trimming (AWTAdaboost) is used in this paper, so thepenalty factor-based AWTAdaboost (PF_AWTAdaboost) is finally obtained.Finally, PF_AWTAdaboost is experimentally validated against other traditionalmachine learning algorithms on credit card fraud datasets and otherdatasets. The results show that the PF_AWTAdaboost method has betterperformance, including detection accuracy, model recall and robustness, thanother methods on the credit card fraud dataset. And the PF_AWTAdaboostmethod also shows excellent generalization performance on other datasets.From the experimental results, it is shown that the PF_AWTAdaboost algorithmhas better classification performance.

A Credit Card Fraud Detection Model Based on Multi-Feature Fusion and Generative Adversarial Network

Credit Card Fraud Detection(CCFD)is an essential technology for banking institutions to control fraud risks and safeguard their reputation.Class imbalance and insufficient representation of feature data relating to credit card transactions are two prevalent issues in the current study field of CCFD,which significantly impact classification models’performance.To address these issues,this research proposes a novel CCFD model based on Multifeature Fusion and Generative Adversarial Networks(MFGAN).The MFGAN model consists of two modules:a multi-feature fusion module for integrating static and dynamic behavior data of cardholders into a unified highdimensional feature space,and a balance module based on the generative adversarial network to decrease the class imbalance ratio.The effectiveness of theMFGAN model is validated on two actual credit card datasets.The impacts of different class balance ratios on the performance of the four resamplingmodels are analyzed,and the contribution of the two different modules to the performance of the MFGAN model is investigated via ablation experiments.Experimental results demonstrate that the proposed model does better than state-of-the-art models in terms of recall,F1,and Area Under the Curve(AUC)metrics,which means that the MFGAN model can help banks find more fraudulent transactions and reduce fraud losses.

Credit Card Fraud Detection on Original European Credit Card Holder Dataset Using Ensemble Machine Learning Technique

The proliferation of digital payment methods facilitated by various online platforms and applications has led to a surge in financial fraud,particularly in credit card transactions.Advanced technologies such as machine learning have been widely employed to enhance the early detection and prevention of losses arising frompotentially fraudulent activities.However,a prevalent approach in existing literature involves the use of extensive data sampling and feature selection algorithms as a precursor to subsequent investigations.While sampling techniques can significantly reduce computational time,the resulting dataset relies on generated data and the accuracy of the pre-processing machine learning models employed.Such datasets often lack true representativeness of realworld data,potentially introducing secondary issues that affect the precision of the results.For instance,undersampling may result in the loss of critical information,while over-sampling can lead to overfitting machine learning models.In this paper,we proposed a classification study of credit card fraud using fundamental machine learning models without the application of any sampling techniques on all the features present in the original dataset.The results indicate that Support Vector Machine(SVM)consistently achieves classification performance exceeding 90%across various evaluation metrics.This discovery serves as a valuable reference for future research,encouraging comparative studies on original dataset without the reliance on sampling techniques.Furthermore,we explore hybrid machine learning techniques,such as ensemble learning constructed based on SVM,K-Nearest Neighbor(KNN)and decision tree,highlighting their potential advancements in the field.The study demonstrates that the proposed machine learning models yield promising results,suggesting that pre-processing the dataset with sampling algorithm or additional machine learning technique may not always be necessary.This research contributes to the field of credit card fraud detection by emphasizing the potential of employing machine learning models directly on original datasets,thereby simplifying the workflow and potentially improving the accuracy and efficiency of fraud detection systems.

Credit Card Fraud Detection Using Weighted Support Vector Machine

Credit card fraudulent data is highly imbalanced, and it has presented an overwhelmingly large portion of nonfraudulent transactions and a small portion of fraudulent transactions. The measures used to judge the veracity of the detection algorithms become critical to the deployment of a model that accurately scores fraudulent transactions taking into account case imbalance, and the cost of identifying a case as genuine when, in fact, the case is a fraudulent transaction. In this paper, a new criterion to judge classification algorithms, which considers the cost of misclassification, is proposed, and several undersampling techniques are compared by this new criterion. At the same time, a weighted support vector machine (SVM) algorithm considering the financial cost of misclassification is introduced, proving to be more practical for credit card fraud detection than traditional methodologies. This weighted SVM uses transaction balances as weights for fraudulent transactions, and a uniformed weight for nonfraudulent transactions. The results show this strategy greatly improve performance of credit card fraud detection.

Credit Card Fraud Detection Based on Machine Learning

In recent years,the rapid development of e-commerce exposes great vulnerabilities in online transactions for fraudsters to exploit.Credit card transactions take a salient role in nowadays’online transactions for its obvious advantages including discounts and earning credit card points.So credit card fraudulence has become a target of concern.In order to deal with the situation,credit card fraud detection based on machine learning is been studied recently.Yet,it is difficult to detect fraudulent transactions due to data imbalance(normal and fraudulent transactions),for which Smote algorithm is proposed in order to resolve data imbalance.The assessment of Light Gradient Boosting Machine model which proposed in the paper depends much on datasets collected from clients’daily transactions.Besides,to prove the new model’s superiority in detecting credit card fraudulence,Light Gradient Boosting Machine model is compared with Random Forest and Gradient Boosting Machine algorithm in the experiment.The results indicate that Light Gradient Boosting Machine model has a good performance.The experiment in credit card fraud detection based on Light Gradient Boosting Machine model achieved a total recall rate of 99%in real dataset and fast feedback,which proves the new model’s efficiency in detecting credit card fraudulence.

Real-Time Fraud Detection Using Machine Learning

Credit card fraud remains a significant challenge, with financial losses and consumer protection at stake. This study addresses the need for practical, real-time fraud detection methodologies. Using a Kaggle credit card dataset, I tackle class imbalance using the Synthetic Minority Oversampling Technique (SMOTE) to enhance modeling efficiency. I compare several machine learning algorithms, including Logistic Regression, Linear Discriminant Analysis, K-nearest Neighbors, Classification and Regression Tree, Naive Bayes, Support Vector, Random Forest, XGBoost, and Light Gradient-Boosting Machine to classify transactions as fraud or genuine. Rigorous evaluation metrics, such as AUC, PRAUC, F1, KS, Recall, and Precision, identify the Random Forest as the best performer in detecting fraudulent activities. The Random Forest model successfully identifies approximately 92% of transactions scoring 90 and above as fraudulent, equating to a detection rate of over 70% for all fraudulent transactions in the test dataset. Moreover, the model captures more than half of the fraud in each bin of the test dataset. SHAP values provide model explainability, with the SHAP summary plot highlighting the global importance of individual features, such as “V12” and “V14”. SHAP force plots offer local interpretability, revealing the impact of specific features on individual predictions. This study demonstrates the potential of machine learning, particularly the Random Forest model, for real-time credit card fraud detection, offering a promising approach to mitigate financial losses and protect consumers.

Predicting Credit Card Transaction Fraud Using Machine Learning Algorithms

Credit card fraud is a wide-ranging issue for financial institutions, involving theft and fraud committed using a payment card. In this paper, we explore the application of linear and nonlinear statistical modeling and machine learning models on real credit card transaction data. The models built are supervised fraud models that attempt to identify which transactions are most likely fraudulent. We discuss the processes of data exploration, data cleaning, variable creation, feature selection, model algorithms, and results. Five different supervised models are explored and compared including logistic regression, neural networks, random forest, boosted tree and support vector machines. The boosted tree model shows the best fraud detection result (FDR = 49.83%) for this particular data set. The resulting model can be utilized in a credit card fraud detection system. A similar model development process can be performed in related business domains such as insurance and telecommunications, to avoid or detect fraudulent activity.

Intelligent Financial Fraud Detection Using Artificial Bee Colony Optimization Based Recurrent Neural Network

Frauds don’t follow any recurring patterns.They require the use of unsupervised learning since their behaviour is continually changing.Fraud-sters have access to the most recent technology,which gives them the ability to defraud people through online transactions.Fraudsters make assumptions about consumers’routine behaviour,and fraud develops swiftly.Unsupervised learning must be used by fraud detection systems to recognize online payments since some fraudsters start out using online channels before moving on to other techniques.Building a deep convolutional neural network model to identify anomalies from conventional competitive swarm optimization pat-terns with a focus on fraud situations that cannot be identified using historical data or supervised learning is the aim of this paper Artificial Bee Colony(ABC).Using real-time data and other datasets that are readily available,the ABC-Recurrent Neural Network(RNN)categorizes fraud behaviour and compares it to the current algorithms.When compared to the current approach,the findings demonstrate that the accuracy is high and the training error is minimal in ABC_RNN.In this paper,we measure the Accuracy,F1 score,Mean Square Error(MSE)and Mean Absolute Error(MAE).Our system achieves 97%accuracy,92%precision rate and F1 score 97%.Also we compare the simulation results with existing methods.

aLMGAN-信用卡欺诈检测方法

针对信用卡交易数据的不平衡重叠问题,提出一种基于生成对抗网络的端到端一类分类方法。提出一种基于PCA和T_SNE的混合数据降维方法,对清洗后的数据进行特征降维;将降维后的数据送入所提出的基于LSTM和aMLP的生成对抗网络(aLMGAN),提出一种基于闵可夫斯基距离(Minkowski distance)的损失函数(Min-loss)代替原始生成对抗网络中的交叉熵损失函数,对正常交易数据进行单类稳定训练,形成一种特殊特征模式,区分不属于该特征的异常数据。通过使用kaggle上两个真实的公共信用卡交易数据集进行实验,验证了aLMGAN算法的有效性。

基于图注意力Transformer神经网络的信用卡欺诈检测模型

针对现有模型无法精准识别复杂多变的团伙诈骗模式的问题,提出一种新型实用的基于复杂交易图谱的信用卡反欺诈检测模型。首先,利用用户原始的交易信息构造关联交易图谱;随后,使用图自注意力Transformer神经网络模块直接从交易网络中挖掘团伙欺诈特征,无需构建繁冗的特征工程;最后,通过欺诈预测网络联合优化图谱中的拓扑模式和时序交易模式,实现对欺诈交易的高精度检测。在信用卡交易数据上的反欺诈实验结果表明,所提模型在全部评价指标上均优于7个对比的基线模型:在交易欺诈检测任务中,平均精度(AP)比基准图注意力神经网络(GAT)提升了20%,ROC曲线下方面积(AUC)平均提升了2.7%,验证了所提模型在信用卡欺诈交易检测中的有效性。

基于注意力机制优化的WGAN-BiLSTM信用卡欺诈检测方法

信用卡欺诈是银行操作风险的主要来源之一,对信用卡诈骗交易进行准确的检测对于减少银行经济损失具有重要意义。针对信用卡欺诈检测中存在的数据类别不平衡和数据漂移的问题,提出一种基于注意力机制优化的WGAN-BiLSTM信用卡欺诈检测方法。首先引入Wasserstein距离改进生成对抗网络(GAN),将信用卡数据输入至WGAN(Wasserstein GAN)中,在生成器和判别器相互博弈训练下,得到符合目标分布的欺诈样本;然后,构建结合注意力机制的双向长短期记忆(BiLSTM)网络,在正反两个方向上提取信用卡数据的长时依赖关系;最后,通过Softmax层输出分类结果。在欧洲持卡人数据集上的实验结果表明,所提方法能有效提升信用卡欺诈检测效果。

基于改进SMOTE算法和深度学习集成框架的信用卡欺诈检测

当前机器学习(ML)算法已经被广泛用于信用卡欺诈检测。然而持卡人线上购物的动态性,以及正常和欺诈交易数据严重不平衡问题,影响了分类器的检测精度。为此,提出了基于深度学习集成框架的信用卡欺诈检测方法。首先,通过改进的合成少数类过采样(SMOTE)算法,解决信用卡数据集中欺诈交易和正常交易数量严重不平衡问题。其次,构建堆栈式深度学习集成框架,使用双向长短时记忆网络(Bi-LSTM)和门控循环单元(GRU)作为基础分类器,并通过多层感知机(MLP)作为元分类器,结合集成学习和深度学习的优点提高信用卡欺诈检测率。在公开数据集上的实验结果表明,所提深度学习集成方法与改进SMOTE算法相结合,分别实现了99.57%和99.82%的灵敏度和特异性结果,优于其他先进的信用卡欺诈检测算法。

基于XGBoost与LR融合模型的信用卡欺诈检测

随着银行卡业务的不断发展,各种各样的信用卡欺诈方式已经给金融机构带来严重的威胁,使得信用卡欺诈检测成为一个十分紧迫的任务。为解决此问题,提出一种XGBoost与LR融合模型。该模型首先运用XGBoost算法自动进行特征组合和离散化,然后将新构造的特征向量运用在逻辑回归LR模型上,通过XGBoost与LR融合模型进行分类预测。实验结果表明,与经典传统算法相比,提出的XGBoost与LR融合模型具有更好的欺诈检测性能,提高了信用卡欺诈检测的准确率。

电信网络诈骗非法提供两卡行为司法治理研究

当前法律规范下,大量为电信网络诈骗非法提供两卡行为被以帮助信息网络犯罪活动罪认定并处之以刑罚,不仅难以实现刑法惩罚与保护的目的,反而可能影响社会秩序的稳定,造成刑事司法资源的浪费。对其中形式上符合犯罪构成要件但实质上不需要判处刑罚的案件,在司法裁判中作出罪处理不仅具有必要性,还能够从损害可弥补、被侵害的法益可修复等角度找到理论支撑,在我国现行实体、程序法框架中也是有据可依的。非法提供两卡构成犯罪案件,如果行为人的人身危险性和再犯罪可能性低、行为本身危害性小、行为人事后认罪悔罪并积极退赔退赃或有其他轻微情节,可以考虑在司法裁判时免予刑事处罚。

涉第三方支付平台信用卡冒用行为的司法定性

随着电商平台成为人们日常生活的组成部分,涉第三方支付平台侵财案件时有发生。此类案件主要有两种类型:一是行为人通过诈骗的方式获得他人的第三方支付平台账号密码,再以他人的身份登录该平台实施侵财行为;二是行为人虽未通过违法或犯罪的方式获取他人第三方支付平台账号密码,但仍以他人的名义登录该平台实施侵财行为。在实务界,在第三方支付平台冒用他人信用卡行为被认定为冒用型信用卡盗窃罪或诈骗罪。文章认为,随着第三方支付平台的发展,实务界逐步承认平台用户被骗的可能性;在第三方支付平台上冒用他人信用卡的行为并不因第三方支付平台的介入而影响信用卡诈骗罪的认定,只是由于行为人最终是否掌控财产而存在犯罪形态的差异。

BP神经网络在信用卡欺诈检测中的应用研究

当前,金融领域正面临着信用卡欺诈的严峻挑战。鉴于信用卡的刷卡数据存在不均衡的情况,本研究采用了BP(Back Propagation)神经网络等人工智能技术,其能够在数量庞大的交易下完成欺诈交易的辨识与剔除。基于BP神经网络的欺诈侦察技术,通过对客户的行为数据进行训练,能够构建出一个多层次的神经网络欺诈侦察模型。本文经实验验证了BP神经网络的可行性。

基于图分析算法的信用卡交易欺诈检测

当前,在线信用卡交易欺诈案件快速增加,作案手段和方法更加多变,信用卡交易欺诈检测已成为银行风险防控的重点内容。文章依托近年人工智能领域热门的图分析理论与算法,将信用卡交易数据转化为图结构数据,从而分析信用卡交易欺诈图的社区信息。在此基础上,应用图表示学习算法Deepwalk和机器学习分类器,构建信用卡交易欺诈检测模型,用于预测欺诈行为。实验结果表示,该模型对欺诈行为的检测准确率达70%。

基于三阶段集成学习的信用卡欺诈检测研究

信用卡欺诈是银行业面临的严峻问题,全球每年因信用卡欺诈造成的损失高达数十亿美元。然而信用卡交易数据存在特征冗余和样本不平衡的问题,这无疑增加了模型对少数欺诈交易的检测难度。针对以上问题,本文提出了三阶段集成学习模型“FS-IFKK-Stacking”:基于FS方法的特征选择、基于IFKK方法的不平衡数据处理和基于Stacking方法的异构模型集成。该模型同时解决了由于特征冗余和样本不均衡性导致的过拟合问题,能够更加准确地检测信用卡欺诈交易。基于Kaggle欧洲信用卡交易数据的实验表明:本文提出的“FS-IFKK-Stacking”模型对信用卡欺诈的检测效果明显优于基于原始样本训练的单类模型:在AUC提升0.44%的同时,对欺诈交易的召回率提升了3.27%。

基于VAE-GWO-LightGBM的信用卡欺诈检测方法

针对信用卡欺诈检测中样本数据规模大、计算复杂程度高、数据分布极度不平衡等问题,提出一种结合变分自编码器(VAE)、灰狼算法(GWO)和轻量级梯度提升机(LightGBM)的信用卡欺诈检测(VAE-GWO-LightGBM)方法.对原始数据进行预处理,考虑到数据的不平衡性,采用VAE处理训练样本的数据不平衡问题.在扩充后的平衡数据集上,利用LightGBM作为分类器,并通过智能优化算法(GWO算法)对分类器参数进行寻优,进而获得最优分类器,提高欺诈检测性能.最后在信用卡欺诈数据和其他不平衡数据集上进行对比实验验证.结果表明,基于VAE-GWO-LightGBM的融合模型从整体上大大提高了信用卡欺诈检测的识别率.