Xiaohong Zhang

Guowei Yin, Sheng Huang, Luwen Huangfu et al.

Feature quality is paramount for classification performance, particularly in few-shot scenarios. Contrastive learning, a widely adopted technique for enhancing feature quality, leverages sample relations to extract intrinsic features that capture semantic information and has achieved remarkable success in Few-Shot Learning (FSL). Nevertheless, current few-shot contrastive learning approaches often overlook the semantic similarity discrepancies at different granularities when employing the same modeling approach for different sample relations, which limits the potential of few-shot contrastive learning. In this paper, we introduce a straightforward yet effective contrastive learning approach, Multi-Grained Relation Contrastive Learning (MGRCL), as a pre-training feature learning model to boost few-shot learning by meticulously modeling sample relations at different granularities. MGRCL categorizes sample relations into three types: intra-sample relation of the same sample under different transformations, intra-class relation of homogenous samples, and inter-class relation of inhomogeneous samples. In MGRCL, we design Transformation Consistency Learning (TCL) to ensure the rigorous semantic consistency of a sample under different transformations by aligning predictions of input pairs. Furthermore, to preserve discriminative information, we employ Class Contrastive Learning (CCL) to ensure that a sample is always closer to its homogenous samples than its inhomogeneous ones, as homogenous samples share similar semantic content while inhomogeneous samples have different semantic content. Our method is assessed across four popular FSL benchmarks, showing that such a simple pre-training feature learning method surpasses a majority of leading FSL methods. Moreover, our method can be incorporated into other FSL methods as the pre-trained model and help them obtain significant performance gains.

Feng Zhu, Zihang Zhang, Kangcheng Teng et al.

High-precision navigation and positioning systems are critical for applications in autonomous vehicles and mobile mapping, where robust and continuous localization is essential. To test and enhance the performance of algorithms, some research institutions and companies have successively constructed and publicly released datasets. However, existing datasets still suffer from limitations in sensor diversity and environmental coverage. To address these shortcomings and advance development in related fields, the SmartPNT Multisource Integrated Navigation, Positioning, and Attitude Dataset has been developed. This dataset integrates data from multiple sensors, including Global Navigation Satellite Systems (GNSS), Inertial Measurement Units (IMU), optical cameras, and LiDAR, to provide a rich and versatile resource for research in multi-sensor fusion and high-precision navigation. The dataset construction process is thoroughly documented, encompassing sensor configurations, coordinate system definitions, and calibration procedures for both cameras and LiDAR. A standardized framework for data collection and processing ensures consistency and scalability, enabling large-scale analysis. Validation using state-of-the-art Simultaneous Localization and Mapping (SLAM) algorithms, such as VINS-Mono and LIO-SAM, demonstrates the dataset's applicability for advanced navigation research. Covering a wide range of real-world scenarios, including urban areas, campuses, tunnels, and suburban environments, the dataset offers a valuable tool for advancing navigation technologies and addressing challenges in complex environments. By providing a publicly accessible, high-quality dataset, this work aims to bridge gaps in sensor diversity, data accessibility, and environmental representation, fostering further innovation in the field.