Adaptive Graph Learning Research Articles

Discriminative Label Relaxed Regression with Adaptive Graph Learning.

The traditional label relaxation regression (LRR) algorithm directly fits the original data without considering the local structure information of the data. While the label relaxation regression algorithm of graph regularization takes into account the local geometric information, the performance of the algorithm depends largely on the construction of graph. However, the traditional graph structures have two defects. First of all, it is largely influenced by the parameter values. Second, it relies on the original data when constructing the weight matrix, which usually contains a lot of noise. This makes the constructed graph to be often not optimal, which affects the subsequent work. Therefore, a discriminative label relaxation regression algorithm based on adaptive graph (DLRR_AG) is proposed for feature extraction. DLRR_AG combines manifold learning with label relaxation regression by constructing adaptive weight graph, which can well overcome the problem of label overfitting. Based on a large number of experiments, it can be proved that the proposed method is effective and feasible.

Co-Saliency Detection via a General Optimization Model and Adaptive Graph Learning

Co-saliency detection is an important research problem, and has been widely used in computer vision area. One main challenge for co-saliency detection problem is how to explore both interactive information among different images and individual salient information within each image simultaneously in co-saliency estimation. In this paper, we propose a novel general optimization framework with adaptive graph learning for co-saliency estimation problem. The proposed model integrates multiple cues including background, and foreground priors, structural information of images, and image feature representation together to obtain a uniform, and accurate co-saliency estimation. One main benefit of the proposed co-saliency method is that it conducts co-saliency propagation, and prediction across different images while maintains the individual salient information of each image, which ensures the consistency, and communication across different images effectively in co-saliency estimation. To improve the accuracy of co-saliency estimation, we adaptively learn a neighborhood, and structured graph to conduct co-saliency propagation among superpixels. An effective optimization algorithm has been designed to seek the optimal solution for the proposed co-saliency optimization model. Experimental results on several widely used datasets show that our method outperforms some other related co-saliency detection methods.

Supervised Graph Clustering for Cancer Subtyping Based on Survival Analysis and Integration of Multi-Omic Tumor Data.

Identifying cancer subtypes by integration of multi-omic data is beneficial to improve the understanding of disease progression, and provides more precise treatment for patients. Cancer subtypes identification is usually accomplished by clustering patients with unsupervised learning approaches. Thus, most existing integrative cancer subtyping methods are performed in an entirely unsupervised way. An integrative cancer subtyping approach can be improved to discover clinically more relevant cancer subtypes when considering the clinical survival response variables. In this study, we propose a Survival Supervised Graph Clustering (S2GC)for cancer subtyping by taking into consideration survival information. Specifically, we use a graph to represent similarity of patients, and develop a multi-omic survival analysis embedding with patient-to-patient similarity graph learning for cancer subtype identification. The multi-view (omic)survival analysis model and graph of patients are jointly learned in a unified way. The learned optimal graph can be unitized to cluster cancer subtypes directly. In the proposed model, the survival analysis model and adaptive graph learning could positively reinforce each other. Consequently, the survival time can be considered as supervised information to improve the quality of the similarity graph and explore clinically more relevant subgroups of patients. Experiments on several representative multi-omic cancer datasets demonstrate that the proposed method achieves better results than a number of state-of-the-art methods. The results also suggest that our method is able to identify biologically meaningful subgroups for different cancer types. (Our Matlab source code is available online at github: https://github.com/CLiu272/S2GC).

Latent multi-view semi-supervised classification by using graph learning

Multi-view learning is a hot research direction in the field of machine learning and pattern recognition, which is attracting more and more attention recently. In the real world, the available data commonly include a small number of labeled samples and a large number of unlabeled samples. In this paper, we propose a latent multi-view semi-supervised classification method by using graph learning. This work recovers a latent intact representation to utilize the complementary information of the multi-view data. In addition, an adaptive graph learning technique is adopted to explore the local structure of this latent intact representation. To fully use this latent intact representation to discover the label information of the unlabeled data, we consider to unify the procedures of computing the latent intact representation and the labels of unlabeled data as a whole. An alternating optimization algorithm is designed to effectively solve the optimization of the proposed method. Extensive experimental results demonstrate the effectiveness of our proposed method.

Robust SVM with adaptive graph learning

Support Vector Machine (SVM) has been widely applied in real application due to its efficient performance in the classification task so that a large number of SVM methods have been proposed. In this paper, we present a novel SVM method by taking the dynamic graph learning and the self-paced learning into account. To do this, we propose utilizing self-paced learning to assign important samples with large weights, learning a transformation matrix for conducting feature selection to remove redundant features, and learning a graph matrix from the low-dimensional data of original data to preserve the data structure. As a consequence, both the important samples and the useful features are used to select support vectors in the SVM framework. Experimental analysis on four synthetic and sixteen benchmark data sets demonstrated that our method outperformed state-of-the-art methods in terms of both binary classification and multi-class classification tasks.

Locality Sensitive Discriminative Unsupervised Dimensionality Reduction

Graph-based embedding methods receive much attention due to the use of graph and manifold information. However, conventional graph-based embedding methods may not always be effective if the data have high dimensions and have complex distributions. First, the similarity matrix only considers local distance measurement in the original space, which cannot reflect a wide variety of data structures. Second, separation of graph construction and dimensionality reduction leads to the similarity matrix not being fully relied on because the original data usually contain lots of noise samples and features. In this paper, we address these problems by constructing two adjacency graphs to stand for the original structure featuring similarity and diversity of the data, and then impose a rank constraint on the corresponding Laplacian matrix to build a novel adaptive graph learning method, namely locality sensitive discriminative unsupervised dimensionality reduction (LSDUDR). As a result, the learned graph shows a clear block diagonal structure so that the clustering structure of data can be preserved. Experimental results on synthetic datasets and real-world benchmark data sets demonstrate the effectiveness of our approach.

Person Reidentification via Multi-Feature Fusion With Adaptive Graph Learning.

The goal of person reidentification (Re-ID) is to identify a given pedestrian from a network of nonoverlapping surveillance cameras. Most existing works follow the supervised learning paradigm which requires pairwise labeled training data for each pair of cameras. However, this limits their scalability to real-world applications where abundant unlabeled data are available. To address this issue, we propose a multi-feature fusion with adaptive graph learning model for unsupervised Re-ID. Our model aims to negotiate comprehensive assessment on the consistent graph structure of pedestrians with the help of special information of feature descriptors. Specifically, we incorporate multi-feature dictionary learning and adaptive multi-feature graph learning into a unified learning model such that the learned dictionaries are discriminative and the subsequent graph structure learning is accurate. An alternating optimization algorithm with proved convergence is developed to solve the final optimization objective. Extensive experiments on four benchmark data sets demonstrate the superiority and effectiveness of the proposed method.

Adaptive graph learning and low-rank constraint for supervised spectral feature selection

Spectral feature selection (SFS) effectively improves performance of feature selection by introducing a graph matrix to preserve information of data. However, conventional SFS (1) generally preserves either global structure or local structure of data in selected subset, which is not capable of providing comprehensive information for model to output a robust result; (2) constructs graph matrix by original data, which usually lead to a suboptimal graph matrix because of redundant information; (3) conducts feature selection task depending on the fixed graph matrix, which is easily trapped in local optimization. Thus, we have proposed a novel SFS to (1) preserve both local information and global information of original data in feature-selected subset to provide comprehensive information for learning model; (2) integrate graph construction and feature selection to propose a robust spectral feature selection easily obtaining global optimization of feature selection. Besides, for the proposed problem, we further provide a optimization algorithm to effectively tackle the problem with a fast convergence. The extensive experimental results showed that our proposed method outperforms state-of-the-art feature selection methods, in terms of classification performance.

Incomplete Multiview Spectral Clustering With Adaptive Graph Learning.

In this paper, we propose a general framework for incomplete multiview clustering. The proposed method is the first work that exploits the graph learning and spectral clustering techniques to learn the common representation for incomplete multiview clustering. First, owing to the good performance of low-rank representation in discovering the intrinsic subspace structure of data, we adopt it to adaptively construct the graph of each view. Second, a spectral constraint is used to achieve the low-dimensional representation of each view based on the spectral clustering. Third, we further introduce a co-regularization term to learn the common representation of samples for all views, and then use the k -means to partition the data into their respective groups. An efficient iterative algorithm is provided to optimize the model. Experimental results conducted on seven incomplete multiview datasets show that the proposed method achieves the best performance in comparison with some state-of-the-art methods, which proves the effectiveness of the proposed method in incomplete multiview clustering.

Semi-Supervised Ridge Regression with Adaptive Graph-Based Label Propagation

In order to overcome the drawbacks of the ridge regression and label propagation algorithms, we propose a new semi-supervised classification method named semi-supervised ridge regression with adaptive graph-based label propagation (SSRR-AGLP). Firstly, we present a new adaptive graph-learning scheme and integrate it into the procedure of label propagation, in which the locality and sparsity of samples are considered simultaneously. Then, we introduce the ridge regression algorithm into label propagation to solve the “out of sample” problem. As a consequence, the proposed SSSRR-AGLP integrates adaptive graph learning, label propagation and ridge regression into a unified framework. Finally, an effective iterative updating algorithm is designed for solving the algorithm, and the convergence analysis is also provided. Extensive experiments are conducted on five databases. Through comparing the results with some well-known algorithms, the effectiveness and superiority of the proposed algorithm are demonstrated.

An adaptive graph learning method based on dual data representations for clustering

Adaptive graph learning methods for clustering, which adjust a data similarity matrix while taking into account its clustering capability, have drawn increasing attention in recent years due to their promising clustering performance. Existing adaptive graph learning methods are based on either original data or linearly projected data and thus rely on the assumption that either representation is a good indicator of the underlying data structure. However, this assumption is sometimes not met in high dimensional data. Studies have shown that high-dimensional data in many problems tend to lie on an embedded nonlinear manifold structure. Motivated by this observation, in this paper, we develop dual data representations, i.e., original data and a nonlinear embedding of the data obtained via an Extreme Learning Machine (ELM)-based neural network, and propose to use them as the more reliable basis for graph learning. The resulting algorithm based on ELM and Constrained Laplacian Rank (ELM-CLR) further improves the clustering capability and robustness, while retaining the advantages of adaptive graph learning, such as not requiring any post-processing to extract cluster indicators. The empirical study shows that the proposed algorithm outperforms the state-of-the-art graph-based clustering methods on a broad range of benchmark datasets.