Research on classification method of high myopic maculopathy based on retinal fundus images and optimized ALFA-Mix active learning algorithm

AIM:To conduct a classification study of high myopic maculopathy(HMM)using limited datasets,including tessellated fundus,diffuse chorioretinal atrophy,patchy chorioretinal atrophy,and macular atrophy,and minimize annotation costs,and to optimize the ALFA-Mix active learning algorithm and apply it to HMM classification.METHODS:The optimized ALFA-Mix algorithm(ALFAMix+)was compared with five algorithms,including ALFA-Mix.Four models,including Res Net18,were established.Each algorithm was combined with four models for experiments on the HMM dataset.Each experiment consisted of 20 active learning rounds,with 100 images selected per round.The algorithm was evaluated by comparing the number of rounds in which ALFA-Mix+outperformed other algorithms.Finally,this study employed six models,including Efficient Former,to classify HMM.The best-performing model among these models was selected as the baseline model and combined with the ALFA-Mix+algorithm to achieve satisfactor y classification results with a small dataset.RESULTS:ALFA-Mix+outperforms other algorithms with an average superiority of 16.6,14.75,16.8,and 16.7 rounds in terms of accuracy,sensitivity,specificity,and Kappa value,respectively.This study conducted experiments on classifying HMM using several advanced deep learning models with a complete training set of 4252 images.The Efficient Former achieved the best results with an accuracy,sensitivity,specificity,and Kappa value of 0.8821,0.8334,0.9693,and 0.8339,respectively.Therefore,by combining ALFA-Mix+with Efficient Former,this study achieved results with an accuracy,sensitivity,specificity,and Kappa value of 0.8964,0.8643,0.9721,and 0.8537,respectively.CONCLUSION:The ALFA-Mix+algorithm reduces the required samples without compromising accuracy.Compared to other algorithms,ALFA-Mix+outperforms in more rounds of experiments.It effectively selects valuable samples compared to other algorithms.In HMM classification,combining ALFA-Mix+with Efficient Former enhances model performance,further demonstrating the effectiveness of ALFA-Mix+.

Semi-supervised kernel FCM algorithm for remote sensing image classification

These problems of nonlinearity, fuzziness and few labeled data were rarely considered in traditional remote sensing image classification. A semi-supervised kernel fuzzy C-means （SSKFCM） algorithm is proposed to overcome these disadvantages of remote sensing image classification in this paper. The SSKFCM algorithm is achieved by introducing a kernel method and semi-supervised learning technique into the standard fuzzy C-means （FCM） algorithm. A set of Beijing-1 micro-satellite＇s multispectral images are adopted to be classified by several algorithms, such as FCM, kernel FCM （KFCM）, semi-supervised FCM （SSFCM） and SSKFCM. The classification results are estimated by corresponding indexes. The results indicate that the SSKFCM algorithm significantly improves the classification accuracy of remote sensing images compared with the others.

Ensemble enhanced active learning mixture discriminant analysis model and its application for semi-supervised fault classification

As an indispensable part of process monitoring, the performance of fault classification relies heavily on the sufficiency of process knowledge. However, data labels are always difficult to acquire because of the limited sampling condition or expensive laboratory analysis, which may lead to deterioration of classification performance.To handle this dilemma, a new semi-supervised fault classification strategy is performed in which enhanced active learning is employed to evaluate the value of each unlabeled sample with respect to a specific labeled dataset.Unlabeled samples with large values will serve as supplementary information for the training dataset. In addition,we introduce several reasonable indexes and criteria, and thus human labeling interference is greatly reduced. Finally,the fault classification effectiveness of the proposed method is evaluated using a numerical example and the Tennessee Eastman process.

Combining Committee-Based Semi-Supervised Learning and Active Learning

Many data mining applications have a large amount of data but labeling data is usually difficult, expensive, or time consuming, as it requires human experts for annotation. Semi-supervised learning addresses this problem by using unlabeled data together with labeled data in the training process. Co-Training is a popular semi-supervised learning algorithm that has the assumptions that each example is represented by multiple sets of features （views） and these views are sufficient for learning and independent given the class. However, these assumptions axe strong and are not satisfied in many real-world domains. In this paper, a single-view variant of Co-Training, called Co-Training by Committee （CoBC） is proposed, in which an ensemble of diverse classifiers is used instead of redundant and independent views. We introduce a new labeling confidence measure for unlabeled examples based on estimating the local accuracy of the committee members on its neighborhood. Then we introduce two new learning algorithms, QBC-then-CoBC and QBC-with-CoBC, which combine the merits of committee-based semi-supervised learning and active learning. The random subspace method is applied on both C4.5 decision trees and 1-nearest neighbor classifiers to construct the diverse ensembles used for semi-supervised learning and active learning. Experiments show that these two combinations can outperform other non committee-based ones.

Multi-layer collaborative optimization fusion for semi-supervised learning

Recently,the Cooperative Training Algorithm(CTA),a well-known Semi-Supervised Learning(SSL)technique,has garnered significant attention in the field of image classification.However,traditional CTA approaches face challenges such as high computational complexity and low classification accuracy.To overcome these limitations,we present a novel approach called Weighted fusion based Cooperative Training Algorithm(W-CTA),which leverages the cooperative training technique and unlabeled data to enhance classification performance.Moreover,we introduce the K-means Cooperative Training Algorithm(km-CTA)to prevent the occurrence of local optima during the training phase.Finally,we conduct various experiments to verify the performance of the proposed methods.Experimental results show that W-CTA and km-CTA are effective and efficient on CIFAR-10 dataset.

Semi-supervised learning via manifold regularization

This paper proposes a novel graph-based transductive learning algorithm based on manifold regularization. First, the manifold regularization was introduced to probabilistic discriminant model for semi-supervised classification task. And then a variation of the expectation maximization （EM） algorithm was derived to solve the optimization problem, which leads to an iterative algorithm. Although our method is developed in probabilistic framework, there is no need to make assumption about the specific form of data distribution. Besides, the crucial updating formula has closed form. This method was evaluated for text categorization on two standard datasets, 20 news group and Reuters-21578. Experiments show that our approach outperforms the state-of-the-art graph-based transductive learning methods.

基于拉普拉斯回归主动学习的大数据流分类算法

实时数据流中标记样本所占比例较小,并且存在大量的噪声数据和冗余数据,导致数据流的实时分类准确率较低。针对这种情况,提出基于拉普拉斯回归主动学习的大数据流分类算法。为分类器设计相对支持度差异函数作为分类的决策方法,通过阈值判断当前数据流的标记样本量。设计基于约束规则的半监督主动学习算法,从无标记样本集选择信息量最丰富的样本。采用拉普拉斯正则最小二乘回归模型作为半监督学习的回归模型,迭代地扩展数据流的标记样本量。仿真结果表明,该算法有效地提高了数据流的分类准确率,并且满足实时性的需求。

融合主动学习的高光谱图像半监督分类

针对高光谱数据维数高、有标签样本少等特点,采用半监督分类利用未标记样本信息提高高光谱图像分类精度。主动学习研究训练样本的选择方法,以少量的标记样本得到尽可能好的泛化能力。本文提出了一种结合主动学习算法的半监督分类算法。该方法使用支持向量机作为基本的学习模型,通过主动学习方法选取训练样本,以伪标记的形式加入到分类器的训练中,结合验证分类器迭代选出置信度较高的伪标记样本,通过差分进化算法交叉变异伪标记样本扩充标记样本群。在两个数据集上进行仿真实验,与传统分类算法相比,所提算法的总体分类精度分别提高了1.97%、0.49%,表明该算法能够有效地提升主动学习样本选择的效率,在有限带标记样本情况下提高了分类器精度。

基于激活漏洞能力条件的软件漏洞自动分类框架

针对软件系统安全缺陷与漏洞问题,提出一种基于激活漏洞条件的自动漏洞分类框架。从文本报告和漏洞代码修复中提取特征,采用不同的机器学习算法(随机森林、用C4.5决策树、Logistic回归和朴素贝叶斯)构建静态模型,选择具有最高F值的模型识别不可见漏洞的类别。通过分析Firefox项目的580项软件安全缺陷来评估分类的有效性。实验结果表明:在所构建框架下,C4.5决策树在几种分类器中具有最优F值来识别不可见漏洞类别。在RedhatBugzilla数据集上将本算法与其他算法进行比较,结果表明本算法对软件漏洞缺陷的分类性能更优,证明了算法的有效性。

基于多级神经元的神经网络及其在分类中的应用

为了提高前向神经网络的分类能力,该文将多级神经元扩展使用到多层感知器的输出层和隐含层中,并提出了量子神经网络的学习算法。通过一个实际的分类问题实验验证了该方法的有效性。实验表明,无论输出层或隐含采用多级神经元,都可以带来分类能力的提高。而当输出层采用多级神经元时,还可以导致连接的减少和训练速度的加快。

基于主动学习的图半监督分类算法

为抑制噪声数据对分类结果的影响,将噪声处理算法与高斯随机域算法相结合,提出一种带噪声系数的高斯随机域学习算法;针对样本集不平衡性数据分类问题,考虑主动学习在样本不平衡问题中的应用,将主动学习与图半监督算法相结合,提出一种鲁棒性强的主动学习图半监督分类算法。利用基于样本划分的主动学习方法,对正类的近邻样本集中样本与特定类样本形成的新样本集做总体散度排序,筛选出能使新样本集中总体散度最小的样本,代替正类的近邻样本集中所有样本,形成平衡类。在UCI标准数据集上的实验结果表明,与标准的图半监督算法相比,该算法的分类精度更高、泛化能力更强。

群体主动学习算法的移动电力交易行为研究

移动端电力交易信息服务提升发电企业、售电公司、购电用户的业务规模,市场成员多边交易,实现多品类交易供需互补。分析移动端电力市场成员的交易行为,提出基于群体主动学习的KNN算法。群体主动学习策略有效构造训练集,首先随机分组选择未标记样本构成候选集,其次计算未标记分组样本的个体距离累加平均值的偏差,接着筛选满足偏差支持度的候选集,加入训练集中,最后给出相应的算法步骤。结合移动端电力市场交易数据进行算例分析,计算电力用户满意度、地域、时间、成交电价综合特征的皮尔逊相关系数,分类出相似购电用户。多种算法实验进行对比和性能分析,结果表明:群体主动学习KNN算法的时间和精确度达到预期要求,具有较好的分类效果,适用于移动端电力市场交易行为分析和供需决策。

基于平衡度调整策略的Ba-AL主动学习算法

提出一种面向不平衡数据的主动学习算法Balance adjustment Active Learning(简称Ba-AL).每次迭代结束检查训练集样本平衡度,对不平衡训练集进行聚类并剔除冗余样本,保持训练集的平衡,从而提高分类效果.UCI数据集及真实的遥感影像数据集仿真结果表明,该方法可以获得较好的分类效果,达到目标正确率所需的最少训练样本数更少,算法效率更高,数据利用指标更优越.