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With the continuous expansion of software scale, software update andmaintenance have become more and more important. However, frequent software code updates will make the software more likely to introduce new defects. So how to predict the defects quickly and accurately on the software change has become an important problem for software developers. Current defect prediction methods often cannot reflect the featureinformation of the defect comprehensively, and the detection effect is not ideal enough.Therefore, we propose a novel defect prediction model named ITNB (Improved TransferNaive Bayes) based on improved transfer Naive Bayesian algorithm in this paper, whichmainly considers the following two aspects: (1) Considering that the edge data of the testset may affect the similarity calculation and final prediction result, we remove the edge dataof the test set when calculating the data similarity between the training set and the test set;(2) Considering that each feature dimension has different effects on defect prediction, weconstruct the calculation formula of training data weight based on feature dimension weightand data gravity, and then calculate the prior probability and the conditional probability oftraining data from the weight information, so as to construct the weighted bayesian classifier for software defect prediction. To evaluate the performance of the ITNB model, we use six datasets from large open source projects, namely Bugzilla, Columba, Mozilla, JDT, Platform and PostgreSQL. We compare the ITNB model with the transfer Naive Bayesian (TNB) model. The experimental results show that our ITNB model can achieve better results than the TNB model in terms of accurary, precision and pd for within-project and cross-project defect prediction. 相似文献
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Lanyan Xue;Wenjun Zhang;Lizheng Lu;Yunsheng Chen;Kaibin Li; 《International journal of imaging systems and technology》2024,34(5):e23151
Automatic segmentation of the fundus retinal vessels and accurate classification of the arterial and venous vessels play an important role in clinical diagnosis. This article proposes a fundus retinal vascular segmentation and arteriovenous classification network that combines the adversarial training and attention mechanism to address the issues of fundus retinal arteriovenous classification error and ambiguous segmentation of fine blood vessels. It consists of three core components: discriminator, generator, and segmenter. In order to address the domain shift issue, U-Net is employed as a discriminator, and data samples for arterial and venous vessels are generated with a generator using an unsupervised domain adaption (UDA) approach. The classification of retinal arterial and venous vessels (A/V) as well as the segmentation of fine vessels is improved by adding a self-attention mechanism to improve attention to vessel edge features and the terminal fine vessels. Non-strided convolution and non-pooled downsampling methods are also used to avoid losing fine-grained information and learning less effective feature representations. The performance of multi-class blood vessel segmentation is as follows, per test results on the DRIVE dataset: F1-score (F1) has a value of 0.7496 and an accuracy of 0.9820. The accuracy of A/V categorization has increased by 1.35% when compared to AU-Net. The outcomes demonstrate that by enhancing the baseline U-Net, the strategy we suggested enhances the automated classification and segmentation of blood vessels. 相似文献
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基于深度学习的故障诊断方法被广泛应用于以轴承为代表的机械关键部件故障诊断,其取得理想效果的前提是有足量故障样本且训练集、测试集满足同分布要求.然而,在实际工况下数据分布会发生变化,进而使原有工况下的诊断模型很难适用于新工况.为此,域适应类迁移学习方法被用于解决训练集、测试集分布不同的问题,其重点在于实现数据分布适应,即度量数据分布差异,并利用度量结果对模型训练进行指导,从而提升学习效率和诊断准确率.在此基础上,提出了一种基于对抗学习的域适应方法,该方法的核心是将提出的指数调节策略与对抗网络相结合,使得网络在故障诊断过程中更有针对性地适应目标域的数据分布.该网络由特征提取器、分类器、一个全局域鉴别器和多个局部域鉴别器组成,利用对抗策略和适应性矩估计算法对模型进行优化,并通过基于指数调节策略设定的指数自适应因子对模型中的边缘分布和条件分布重要性进行调节,使得模型可以稳定、高效地进行故障诊断.在跨转速、跨负载和同时跨转速和负载的轴承诊断案例中对提出的方法进行验证,结果表明本文方法的诊断效果优于其他域适应方法,并具有较好的稳定性. 相似文献
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The majority of big data analytics applied to transportation datasets suffer from being too domain-specific, that is, they draw conclusions for a dataset based on analytics on the same dataset. This makes models trained from one domain (e.g. taxi data) applies badly to a different domain (e.g. Uber data). To achieve accurate analyses on a new domain, substantial amounts of data must be available, which limits practical applications. To remedy this, we propose to use semi-supervised and active learning of big data to accomplish the domain adaptation task: Selectively choosing a small amount of datapoints from a new domain while achieving comparable performances to using all the datapoints. We choose the New York City (NYC) transportation data of taxi and Uber as our dataset, simulating different domains with 90% as the source data domain for training and the remaining 10% as the target data domain for evaluation. We propose semi-supervised and active learning strategies and apply it to the source domain for selecting datapoints. Experimental results show that our adaptation achieves a comparable performance of using all datapoints while using only a fraction of them, substantially reducing the amount of data required. Our approach has two major advantages: It can make accurate analytics and predictions when big datasets are not available, and even if big datasets are available, our approach chooses the most informative datapoints out of the dataset, making the process much more efficient without having to process huge amounts of data. 相似文献
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故障数据的缺失一直是制约设备故障诊断发展的重要因素,现有研究通过刻意损坏设备的方法来采集故障数据。为实现座椅电机的无损故障诊断,文章对座椅电机的故障机理进行分析,确定可能发生的故障类型,通过在座椅电机表面粘贴微型喇叭并播放故障声音,来模拟故障的发生。在自编码器系统的基础上,引入卷积操作,使用卷积层代替全连接层,通过输入数据维度、卷积核的尺寸和数量以及池化、正则化等操作对模型结构进行调整。采用IDMT Isa Electric Engine数据集作为源域数据,对模型进行预训练。使用迁移学习方法将源域中已经学习到的数据分布迁移到座椅电机故障诊断任务中,并与各类模型检测结果进行对比。结果显示,文中方法在召回率保持1.00的情况下,曲线下面积达到0.86,检测结果可靠,具有实际应用价值。 相似文献
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Haiwen Chen Guang Yu Fang Liu Zhiping Cai Anfeng Liu Shuhui Chen Hongbin Huang Chak Fong Cheang 《计算机、材料和连续体(英文)》2020,62(2):917-927
For many Internet companies, a huge amount of KPIs (e.g., server CPU usage, network usage, business monitoring data) will be generated every day. How to closely monitor various KPIs, and then quickly and accurately detect anomalies in such huge data for troubleshooting and recovering business is a great challenge, especially for unlabeled data. The generated KPIs can be detected by supervised learning with labeled data, but the current problem is that most KPIs are unlabeled. That is a time-consuming and laborious work to label anomaly for company engineers. Build an unsupervised model to detect unlabeled data is an urgent need at present. In this paper, unsupervised learning DBSCAN combined with feature extraction of data has been used, and for some KPIs, its best F-Score can reach about 0.9, which is quite good for solving the current problem. 相似文献
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Ru Zhang;Fangmin Sheng;Lei Wang;Weiming Zeng; 《International journal of imaging systems and technology》2024,34(3):e23110
Autism Spectrum Disorder (ASD) is a complex neurodevelopmental disorder, and structural magnetic resonance imaging (sMRI) and functional magnetic resonance imaging (fMRI) provide information about brain structure and function, aiding in objective ASD diagnosis. However, existing ASD classification methods face challenges such as sample scarcity, inter-imaging center variations, insufficient single-modality information, and inconsistent feature dimensions. This study introduced a method based on the Local Global Multimodal Domain Adaptation (LGMDA)-Sparse Adaptive Prior Coupled Dictionary Learning (SACDL) framework. Initially, the LGMDA method was introduced to achieve multi-source DA. By minimizing differences between different data domains while maximizing inter-class differences within the same domain, it expands the sample size of multi-modal data, addressing the issues of sample scarcity and heterogeneity in ASD data. Subsequently, the SACDL method was employed for multimodal fusion. It initialized dictionaries using the ATGP algorithm, combined sMRI and fMRI data for dictionary learning, adaptively adjusted sparsity parameters, and integrated ASD phenotype data for constrained optimization. It enables joint learning of shared and modality-specific features, balancing differences in feature dimensions. Experimental results show that this model effectively utilizes multi-center, multi-modal information to achieve better auxiliary diagnosis than single-modal small samples. This method has the potential to provide effective solutions for ASD multi-source and multi-modal classification problems, which are significant for ASD research and clinical diagnosis. 相似文献
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文章基于多示例学习的跟踪框架,引入改进型的分布场特征并融合目标时间维度信息,提出了一种新的跟踪算法。新的特征能够更为有效地描述目标的空间结构信息,对于目标模糊、局部遮挡以及细微形变有良好的鲁棒性。加入的目标时间维度信息融合方法,包含了目标的历史信息,同时也能响应目标的外观变化,提高了跟踪器从跟踪异常中恢复的能力。通过对比新算法与其他先进算法在多组测试视频上的跟踪结果,可以发现本文提出的算法具有更为优异的性能,能够在各种复杂情况下对目标进行稳定的跟踪。 相似文献
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Software defect prediction is a research hotspot in the field of software engineering. However, due to the limitations of current machine learning algorithms, we can’t achieve good effect for defect prediction by only using machine learning algorithms. In previous studies, some researchers used extreme learning machine (ELM) to conduct defect prediction. However, the initial weights and biases of the ELM are determined randomly, which reduces the prediction performance of ELM. Motivated by the idea of search based software engineering, we propose a novel software defect prediction model named KAEA based on kernel principal component analysis (KPCA), adaptive genetic algorithm, extreme learning machine and Adaboost algorithm, which has three main advantages: (1) KPCA can extract optimal representative features by leveraging a nonlinear mapping function; (2) We leverage adaptive genetic algorithm to optimize the initial weights and biases of ELM, so as to improve the generalization ability and prediction capacity of ELM; (3) We use the Adaboost algorithm to integrate multiple ELM basic predictors optimized by adaptive genetic algorithm into a strong predictor, which can further improve the effect of defect prediction. To effectively evaluate the performance of KAEA, we use eleven datasets from large open source projects, and compare the KAEA with four machine learning basic classifiers, ELM and its three variants. The experimental results show that KAEA is superior to these baseline models in most cases. 相似文献
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Software defect prediction plays a very important role in software quality assurance, which aims to inspect as many potentially defect-prone software modules as possible. However, the performance of the prediction model is susceptible to high dimensionality of the dataset that contains irrelevant and redundant features. In addition, software metrics for software defect prediction are almost entirely traditional features compared to the deep semantic feature representation from deep learning techniques. To address these two issues, we propose the following two solutions in this paper: (1) We leverage a novel non-linear manifold learning method - SOINN Landmark Isomap (SLIsomap) to extract the representative features by selecting automatically the reasonable number and position of landmarks, which can reveal the complex intrinsic structure hidden behind the defect data. (2) We propose a novel defect prediction model named DLDD based on hybrid deep learning techniques, which leverages denoising autoencoder to learn true input features that are not contaminated by noise, and utilizes deep neural network to learn the abstract deep semantic features. We combine the squared error loss function of denoising autoencoder with the cross entropy loss function of deep neural network to achieve the best prediction performance by adjusting a hyperparameter. We compare the SL-Isomap with seven state-of-the-art feature extraction methods and compare the DLDD model with six baseline models across 20 open source software projects. The experimental results verify that the superiority of SL-Isomap and DLDD on four evaluation indicators. 相似文献
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This study presents a hybrid learning neural fuzzy system for accurately predicting system reliability. Neural fuzzy system learning with and without supervision has been successfully applied in control systems and pattern recognition problems. This investigation modifies the hybrid learning fuzzy systems to accept time series data and therefore examines the feasibility of reliability prediction. Two neural network systems are developed for solving different reliability prediction problems. Additionally, a scaled conjugate gradient learning method is applied to accelerate the training in the supervised learning phase. Several existing approaches, including feed‐forward multilayer perceptron (MLP) networks, radial basis function (RBF) neural networks and Box–Jenkins autoregressive integrated moving average (ARIMA) models, are used to compare the performance of the reliability prediction. The numerical results demonstrate that the neural fuzzy systems have higher prediction accuracy than the other methods. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
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无监督行人重识别因其广泛的实际应用前景而受到越来越多的关注。大多数基于聚类的对比学习方法将每个集群视为一个伪身份类,忽略了由相机风格差异造成的类内差异。一些方法引入了相机感知对比学习,根据相机视角将单一集群划分为多个子集群,但它们容易受到噪声伪标签的误导。为解决这一问题,本文首先基于实例在特征空间中的相似性,采用最近邻的预测标签和原始聚类结果的加权组合细化伪标签。然后,采用细化伪标签动态地关联实例可能属于的类别中心,同时剔除可能存在的假阴性样本。这一方法改进了相机感知对比学习中正负样本的选择机制,有效地减轻了噪声伪标签对对比学习任务的误导。在Market-1501、MSMT17、Personx数据集上mAP/Rank-1分别达到了85.2%/94.4%、44.3%/74.1%、88.7%/95.9%。 相似文献
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针对无监督域自适应行人重识别中存在的感受野不足、全局特征与局部特征联系不紧密等问题,提出了一种多尺度特征交互的无监督域自适应行人重识别方法。首先利用特征压缩注意力机制对图像特征进行压缩并输入到网络以增强丰富的局部信息。其次,设计了残差特征交互模块,通过特征交互的方式将全局信息编码到特征中,同时增大模型感受野,强化网络对行人特征信息的提取能力。最后,采用基于部分卷积的瓶颈层模块在部分输入通道上进行卷积运算以减少冗余计算,提高空间特征提取效率。实验结果显示,该方法在三个适应性数据集上mAP分别达到了82.9%、68.7%、26.6%,Rank-1分别达到了93.7%、82.7%、54.7%,Rank-5分别达到了97.4%、89.9%、67.5%。表明所提方法能够使行人特征得到更好的表达,识别精度得到提高。 相似文献
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Software defect prediction plays an important role in software quality assurance. However, the performance of the prediction model is susceptible to the irrelevant and redundant features. In addition, previous studies mostly regard software defect prediction as a single objective optimization problem, and multi-objective software defect prediction has not been thoroughly investigated. For the above two reasons, we propose the following solutions in this paper: (1) we leverage an advanced deep neural network—StackedContractive AutoEncoder (SCAE) to extract the robust deep semantic features from the original defect features, which has stronger discrimination capacity for different classes (defective or non-defective). (2) we propose a novel multi-objective defect prediction model named SMONGE that utilizes the Multi-Objective NSGAII algorithm to optimizethe advanced neural network—Extreme learning machine (ELM) based on state-of-the-art Pareto optimal solutions according to the features extracted by SCAE. We mainly consider two objectives. One objective is to maximize the performance of ELM, which refers to the benefit of the SMONGE model. Another objective is to minimize the output weight normof ELM, which is related to the cost of the SMONGE model. We compare the SCAE with six state-of-the-art feature extraction methods and compare the SMONGE model with multiple baseline models that contain four classic defect predictors and the MONGE modelwithout SCAE across 20 open source software projects. The experimental results verify that the superiority of SCAE and SMONGE on seven evaluation metrics. 相似文献
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卫星云图能从多角度展示各类云系特征及其演变过程,实现基于内容的云图检索在天气实况监测、气候研究等方面具有重要意义。为了优化云图的组合特征,增强其组合特征的泛化能力,本文提出一种结合稀疏表示和子空间投影的特征优化方法。首先分别提取云图的颜色、纹理以及形状三种特征,并对其组合特征进行转换分块;然后对每一块的特征进行稀疏表示,根据不同原子的方差来分组特征,得到显著特征和非显著特征;最后由分组特征的能量来计算得到子空间投影矩阵,将初始的组合特征在投影矩阵上进行投影,得到优化后的云图特征。实验结果表明,本文优化云图特征的方法在查准率、查全率上均优于常用的降维方法和云图检索技术,对组合特征具有较强的优化能力,在实时检索过程中时间复杂度低,是一种全新的检索方法。 相似文献
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粉末高温合金缺陷特性及寿命预测方法研究进展和思考 总被引:1,自引:0,他引:1
系统分析了国内外在粉末高温合金缺陷特性及寿命预测方法方面的研究进展,如缺陷的来源及对寿命的影响,缺陷对裂纹萌生和扩展的影响,粉末高温合金寿命预测方法和模型.在研究目前国内外寿命预测方法的基础上,结合我国粉末高温合金寿命预测存在的问题,指出必须考虑缺陷特性并对缺陷进行定量表征,建立反映粉末高温合金特点和缺陷特性的寿命预测方法. 相似文献
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Antoine Benady;Emmanuel Baranger;Ludovic Chamoin; 《International journal for numerical methods in engineering》2024,125(8):e7439
This article proposes a new approach to train physics-augmented neural networks with observable data to represent mechanical constitutive laws. To train the neural network and learn thermodynamics potentials, the proposed method does not rely on strain-stress or strain-free energy pairs but needs only partial strain or displacement measurements inside the structure. The neural network is trained thanks to an unsupervised procedure in which the modified constitutive relation error (mCRE) is minimized. The mCRE functional provides a bias-aware data assimilation framework with a rich physical sense as the constitutive relation error (CRE) part can be interpreted as a modeling error continuously defined over the structure, and can be used as a prediction quality in the inference phase. This article also extends previous works on the mCRE by introducing a new minimization procedure in the case of nonlinear state laws. As typical structural health monitoring applications may require that the neural networks should be trained online, an important focus is thus made on automatic and adaptive tuning of sensitive hyperparameters (learning rate, weighting between losses, number of epochs and initialization). It is shown that when the training database is rich enough with respect to the loading cases, the proposed method achieves remarkable performance regarding the quality of the learned model, noise robustness, and low sensitivity to user-defined hyperparameters. The method is evaluated on two test cases: a non-quadratic potential in the small strain regime with synthetic optic fiber measurements, and a Mooney–Rivlin model in the hyperelastic case with synthetic digital image correlation observations. 相似文献