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Partially labeled and skewed datasets are common in many applications including healthcare, due to the high costs and time constraints of data collection and annotation. However, training machine learning classifiers on such data can undermine their prediction performances. In this paper, we propose a novel classifier to address this problem by focusing on the Area Under the Curve (AUC), which is widely recognized as a more robust performance metric for skewed datasets than other metrics such as accuracy and error rate. We introduce a new classifier called PSVM-AUC Maximizer (PSVM-AUCMax) which is based on Proximal Support Vector Machines (PSVM) and directly maximizes a new AUC-based metric in its learning objective. PSVM-AUCMax has several merits. First, by directly integrating the maximization of the proposed AUC-based metric, PSVM-AUCMax can be proved to have the enhanced generalization capability on the partially labeled and skewed dataset. Second, it simplifies the model selection process with fewer tuning hyperparameters. Third, PSVM-AUCMax's analytical solution remains the same form as traditional PSVM, preserving its advantages such as fast incremental updating in incremental learning scenarios. The efficacy of PSVM-AUCMax has been demonstrated through extensive experiments on several public datasets and a healthcare case study using data collected at the US Mayo Clinic. In the healthcare case study, we utilized PSVM-AUCMax to develop a clinical prediction model for forecasting composite outcomes in hospitalized COVID-19 patients which yielded promising results. [ABSTRACT FROM AUTHOR]

• A novel concept and framework is introduced to directly match 2D and 3D features. • The framework is used for 6-DOF pose estimation, and camera and visual localization. • Current techniques usually rely on Structure from Motion models for localization. • Proposed framework can be used for any type of 3D models and point clouds. • The method outperforms state-of-the-art techniques on benchmark datasets. This paper presents a novel approach for cross-domain descriptor matching between 2D and 3D modalities. The 2D-3D matching is applied to localize 2D images in 3D point clouds. Direct cross-domain matching allows our technique to localize images in any type of 3D point cloud without any constraints on the nature or mechanism by which it is obtained. We propose a learning based framework, called Desc-Matcher, to directly match features between the two modalities. A dataset of 2D and 3D features with corresponding locations in images and point clouds is generated to train the Desc-Matcher. To estimate the pose of an image in any 3D cloud, keypoints and feature descriptors are extracted from the query image and the point cloud. The trained Desc-Matcher is then used to match the features from the image and the point cloud. A robust pose estimator is used to predict the location and orientation of the query image from the corresponding positions of the matched 2D and 3D features. We carried out an extensive evaluation of the proposed method for indoor and outdoor scenarios and with different types of point clouds to verify the feasibility of our approach. Experimental results show that the proposed approach can reliably estimate the 6-DOF poses of query cameras in any type of 3D point cloud with high precision. We achieved average median errors of 1.09 c m / 0. 27 ∘ and 19 c m / 0. 39 ∘ on the Stanford and Cambridge datasets, respectively. [ABSTRACT FROM AUTHOR]

By introducing sign constraints on the weights, this paper proposes sign constrained rectifier networks (SCRNs), whose training can be solved efficiently by the well known majorization–minimization (MM) algorithms. We prove that the proposed two-hidden-layer SCRNs, which exhibit negative weights in the second hidden layer and negative weights in the output layer, are capable of separating any number of disjoint pattern sets. Furthermore, the proposed two-hidden-layer SCRNs can decompose the patterns of each class into several clusters so that each cluster is convexly separable from all the patterns from the other classes. This provides a means to learn the pattern structures and analyse the discriminant factors between different classes of patterns. Experimental results are provided to show the benefits of sign constraints in improving classification performance and the efficiency of the proposed MM algorithm. [ABSTRACT FROM AUTHOR]

Oceanographers rely on advanced digital imaging systems to assess the health of marine ecosystems. The majority of the imagery collected by these systems do not get annotated due to lack of resources. Consequently, the expert labeled data is not enough to train dedicated deep networks. Meanwhile, in the deep learning community, much focus is on how to use pre-trained deep networks to classify out-of-domain images and transfer learning. In this paper, we leverage these advances to evaluate how well features extracted from deep neural networks transfer to underwater image classification. We propose new image features (called ResFeats) extracted from the different convolutional layers of a deep residual network pre-trained on ImageNet. We further combine the ResFeats extracted from different layers to obtain compact and powerful deep features. Moreover, we show that ResFeats consistently perform better than their CNN counterparts. Experimental results are provided to show the effectiveness of ResFeats with state-of-the-art classification accuracies on MLC, Benthoz15, EILAT and RSMAS datasets. • Introduction of ResFeats (features extracted from deep residual network) • Application of ResFeats to underwater image classification • Combining ResFeats from different layers for improved performance • Superior classification performance over previous CNN features • State-of-the-art results on four marine datasets [ABSTRACT FROM AUTHOR]

Point clouds provide rich geometric information about a shape and a deep neural network can be used to learn effective and robust features. In this paper, we propose a novel local feature descriptor, which employs a Siamese network to directly learn robust features from the point clouds. We use a data representation based on the Mercator projection, then we use a Siamese network to map this projection into a 32-dimensional local descriptor. To validate the proposed method, we have compared it with seven state-of-the-art descriptor methods. Experimental results show the superiority of the proposed method compared to existing methods in terms of descriptiveness and robustness against noise and varying mesh resolutions. • This paper introduces a low complexity and low-dimensional local descriptor. • We learn a novel data representation based on the Mercator projection. • We achieve this using a Siamese network that directly learns from point clouds. • We report superior performance against noise and varying mesh resolutions. [ABSTRACT FROM AUTHOR]