基于中心对齐多核学习的稀疏多元逻辑回归算法

稀疏多元逻辑回归(SMLR)作为一种广义的线性模型被广泛地应用于各种多分类任务场景中。SMLR通过将拉普拉斯先验引入多元逻辑回归(MLR)中使其解具有稀疏性，这使得该分类器可以在进行分类的过程中嵌入特征选择。为了使分类器能够解决非线性数据分类的问题，该文通过核技巧对SMLR进行核化扩充后得到了核稀疏多元逻辑回归(KSMLR)。KSMLR能够将非线性特征数据通过核函数映射到高维甚至无穷维的特征空间中，使其特征能够充分地表达并最终能进行有效的分类。此外，该文还利用了基于中心对齐的多核学习算法，通过不同的核函数对数据进行不同维度的映射，并用中心对齐相似度来灵活地选取多核学习权重系数，使得分类器具有更好的泛化能力。实验结果表明，该文提出的基于中心对齐多核学习的稀疏多元逻辑回归算法在分类的准确率指标上都优于目前常规的分类算法。

Sparse Multinomial Logistic Regression Algorithm Based on Centered Alignment Multiple Kernels Learning

As a generalized linear model, Sparse Multinomial Logistic Regression (SMLR) is widely used in various multi-class task scenarios. SMLR introduces Laplace priori into Multinomial Logistic Regression (MLR) to make its solution sparse, which allows the classifier to embed feature selection in the process of classification. In order to solve the problem of non-linear data classification, Kernel Sparse Multinomial Logistic Regression (KSMLR) is obtained by kernel trick. KSMLR can map nonlinear feature data into high-dimensional and even infinite-dimensional feature spaces through kernel functions, so that its features can be fully expressed and eventually classified effectively. In addition, the multi-kernel learning algorithm based on centered alignment is used to map the data in different dimensions through different kernel functions. Then center-aligned similarity can be used to select flexibly multi-kernel learning weight coefficients, so that the classifier has better generalization ability. The experimental results show that the sparse multinomial logistic regression algorithm based on center-aligned multi-kernel learning is superior to the conventional classification algorithm in classification accuracy.