Model-agnostic explanation methods are essential for interpreting machine learning models, but suffer from prohibitive computational costs that scale with the number of baselines. Existing acceleration approaches either lack a theoretical base or provide no principled guidance for baseline selection. To address this gap, we present ABSQR (Amortized Baseline Selection via Rank-Revealing QR). This framework exploits the low-rank structure of value matrices to accelerate multi-baseline attribution methods. Our approach combines deterministic baseline selection via SVD-guided QR decomposition with an amortized inference mechanism that utilizes cluster-based retrieval. We reduce computational complexity from O (m • 2d) to O (k • 2d), where k ≪ m. Experiments demonstrate that ABSQR achieves a 91.2% agreement rate with full baseline methods while providing 8.5× speedup across diverse datasets. As the first acceleration approach that preserves explanation error guarantees under computational speedup, ABSQR makes the practical deployment of interpretable AI systems feasible at scale.

In this paper, we propose an effective multi-stage neural audio coding algorithm that encodes full-band audio signals (up to 20 kHz) using an end-to-end training criterion. By predefining several dyadic subband signals as training targets, we progressively encode input audio signals in each stage such that deeper stages of the network encode the residual error terms from the previous encoding stage. Our proposed audio codec successfully decodes full-band audio signals by using an effective multi-stage vector quantization scheme to represent key encoding features extracted in the latent space. Subjective listening tests show that the decoded outputs of the proposed audio codec achieve almost transparent quality at an average bitrate of 132 kbps.

In this paper, we propose a discriminator design scheme for generative adversarial network-based audio signal generation. Unlike conventional discriminators that take an entire signal as input, our discriminator separates the audio signal into harmonic and percussive components and analyzes each component independently. The rationale behind this idea is that conventional discriminators cannot reliably capture subtle distortions in audio signals, which have complicated time-frequency characteristics. By considering the time-frequency resolution of audio signals, our proposed method encourages the generator to better reconstruct harmonic and percussive features, both of which are critical for the quality of the generated signals. Listening tests show that our framework significantly enhances the stability of pitches and generates clearer piano samples compared to a baseline.

We consider the problem of tensor estimation from noisy observations with possibly missing entries. A nonparametric approach to tensor completion is developed based on a new model which we coin as sign representable tensors. The model represents the signal tensor of interest using a series of structured sign tensors. Unlike earlier methods, the sign series representation effectively addresses both low- and high-rank signals, while encompassing many existing tensor models---including CP models, Tucker models, single index models, structured tensors with repeating entries---as special cases. We provably reduce the tensor estimation problem to a series of structured classification tasks, and we develop a learning reduction machinery to empower existing low-rank tensor algorithms for more challenging high-rank estimation. Excess risk bounds, estimation errors, and sample complexities are established. We demonstrate the outperformance of our approach over previous methods on two datasets, one on human brain connectivity networks and the other on topic data mining.

Higher-order tensors arise frequently in applications such as neuroimaging, recommendation system, and social network analysis. We consider the problem of low-rank tensor estimation from possibly incomplete, ordinal-valued observations. Two related problems are studied, one on tensor denoising and another on tensor completion. We propose a multi-linear cumulative link model, develop a rank-constrained M-estimator, and obtain theoretical accuracy guarantees. Our mean squared error bound enjoys a faster convergence rate than previous results, and we show that the proposed estimator is minimax optimal under the class of low-rank models. Furthermore, the procedure developed serves as an efficient completion method which guarantees consistent recovery of an order-K (d,...,d)-dimensional low-rank tensor using only O(Kd) noisy, quantized observations. We demonstrate the outperformance of our approach over previous methods on the tasks of clustering and collaborative filtering.