As a compromise between supervised and unsupervised learning, semi-supervised learning (SSL) harnesses both labeled and unlabeled data to enhance learning performance. Graph-based semi-supervised learning (GSSL) has emerged as a prominent approach owing to its versatility in representing sample interdependencies via graph structures. However, traditional GSSL methods face high time cost when computing matrix inverses, making them inefficient for large datasets. To address this, some researchers have introduced anchors as a bridge to accelerate the process. Nevertheless, most anchor-based models suffer from one or more of the following issues: (1) The anchor graph-based construction of the adjacency matrix has limitations; (2) The objective functions are typically non-convex, leading to local optima and requiring multiple runs to achieve good performance. To tackle these challenges, we develop a probability-driven approach to build the adjacency matrix, defining sample similarity as the probability of sharing the same anchor. Based on this strategy, we design a model (CFSL) with a strictly convex objective function, guaranteeing a globally optimal solution without iterative optimization. Experiments on multiple datasets indicate that our algorithm yields strong performance.

A robust and efficient pyramid signal Transformer model, called SigFormer for automatic modulation recognition was proposed in this paper. In SigFormer, a pyramid Transformer architecture is introduced to encode the relationship between the internal features of modulated signals. Specifically, a dual-attention block composed of self-attention layer and scaling-attention layer is proposed for simultaneous global feature repre-sentation and noise resistance learning for modulated signals, and small-kernel convolution layers embedded to dual-attention block and feed-forward block is proposed for fine-grained modulation recognition as well. Experiments on RML2018.01a, RML2016.10a and RML2016.10b show that the SigFormer outperformed most other deep learning models on recognition accuracy, and it is more parameter-efficient than most other models and more robust on low signal-to-noise ratio (SNR) signals.

Demand for high-volume 3D scanning of real objects is rapidly growing in a wide range of applications, including online retailing, quality-control for manufacturing, stop motion capture for 3D animation, and archaeological documentation and reconstruction. Although mature technologies exist for high-fidelity 3D model acquisition, deploying them at scale continues to require non-trivial manual labor. We describe a system that allows non-expert users to scan large numbers of physical objects within a reasonable amount of time, and with greater ease. Our system uses novel view- and path-planning algorithms to control a structured-light scanner mounted on a calibrated motorized positioning system. We demonstrate the ability of our prototype to safely, robustly, and automatically acquire 3D models for large collections of small objects.

We propose an approach to enhance rough 3D geometry with fine details obtained from multiple normal maps. We begin with unaligned 2D normal maps and rough geometry, and automatically optimize the alignments through 2-step iterative registration algorithm. We then map the normals onto the surface, correcting and seamlessly blending them together. Finally, we optimize the geometry to produce high-quality 3D models that incorporate the high-frequency details from the normal maps. We demonstrate that our algorithm improves upon the results produced by some well-known algorithms: Poisson surface reconstruction [1] and the algorithm proposed by Nehab et al. [2].