598 research outputs found
LightGrad: Lightweight Diffusion Probabilistic Model for Text-to-Speech
Recent advances in neural text-to-speech (TTS) models bring thousands of TTS
applications into daily life, where models are deployed in cloud to provide
services for customs. Among these models are diffusion probabilistic models
(DPMs), which can be stably trained and are more parameter-efficient compared
with other generative models. As transmitting data between customs and the
cloud introduces high latency and the risk of exposing private data, deploying
TTS models on edge devices is preferred. When implementing DPMs onto edge
devices, there are two practical problems. First, current DPMs are not
lightweight enough for resource-constrained devices. Second, DPMs require many
denoising steps in inference, which increases latency. In this work, we present
LightGrad, a lightweight DPM for TTS. LightGrad is equipped with a lightweight
U-Net diffusion decoder and a training-free fast sampling technique, reducing
both model parameters and inference latency. Streaming inference is also
implemented in LightGrad to reduce latency further. Compared with Grad-TTS,
LightGrad achieves 62.2% reduction in paramters, 65.7% reduction in latency,
while preserving comparable speech quality on both Chinese Mandarin and English
in 4 denoising steps.Comment: Accepted by ICASSP 202
ZeroPrompt: Streaming Acoustic Encoders are Zero-Shot Masked LMs
In this paper, we present ZeroPrompt (Figure 1-(a)) and the corresponding
Prompt-and-Refine strategy (Figure 3), two simple but effective
\textbf{training-free} methods to decrease the Token Display Time (TDT) of
streaming ASR models \textbf{without any accuracy loss}. The core idea of
ZeroPrompt is to append zeroed content to each chunk during inference, which
acts like a prompt to encourage the model to predict future tokens even before
they were spoken. We argue that streaming acoustic encoders naturally have the
modeling ability of Masked Language Models and our experiments demonstrate that
ZeroPrompt is engineering cheap and can be applied to streaming acoustic
encoders on any dataset without any accuracy loss. Specifically, compared with
our baseline models, we achieve 350 700ms reduction on First Token
Display Time (TDT-F) and 100 400ms reduction on Last Token Display Time
(TDT-L), with theoretically and experimentally equal WER on both Aishell-1 and
Librispeech datasets.Comment: accepted by interspeech 202
CB-Conformer: Contextual biasing Conformer for biased word recognition
Due to the mismatch between the source and target domains, how to better
utilize the biased word information to improve the performance of the automatic
speech recognition model in the target domain becomes a hot research topic.
Previous approaches either decode with a fixed external language model or
introduce a sizeable biasing module, which leads to poor adaptability and slow
inference. In this work, we propose CB-Conformer to improve biased word
recognition by introducing the Contextual Biasing Module and the Self-Adaptive
Language Model to vanilla Conformer. The Contextual Biasing Module combines
audio fragments and contextual information, with only 0.2% model parameters of
the original Conformer. The Self-Adaptive Language Model modifies the internal
weights of biased words based on their recall and precision, resulting in a
greater focus on biased words and more successful integration with the
automatic speech recognition model than the standard fixed language model. In
addition, we construct and release an open-source Mandarin biased-word dataset
based on WenetSpeech. Experiments indicate that our proposed method brings a
15.34% character error rate reduction, a 14.13% biased word recall increase,
and a 6.80% biased word F1-score increase compared with the base Conformer
Fast-U2++: Fast and Accurate End-to-End Speech Recognition in Joint CTC/Attention Frames
Recently, the unified streaming and non-streaming two-pass (U2/U2++)
end-to-end model for speech recognition has shown great performance in terms of
streaming capability, accuracy and latency. In this paper, we present
fast-U2++, an enhanced version of U2++ to further reduce partial latency. The
core idea of fast-U2++ is to output partial results of the bottom layers in its
encoder with a small chunk, while using a large chunk in the top layers of its
encoder to compensate the performance degradation caused by the small chunk.
Moreover, we use knowledge distillation method to reduce the token emission
latency. We present extensive experiments on Aishell-1 dataset. Experiments and
ablation studies show that compared to U2++, fast-U2++ reduces model latency
from 320ms to 80ms, and achieves a character error rate (CER) of 5.06% with a
streaming setup.Comment: 5 pages, 3 figure
TrimTail: Low-Latency Streaming ASR with Simple but Effective Spectrogram-Level Length Penalty
In this paper, we present TrimTail, a simple but effective emission
regularization method to improve the latency of streaming ASR models. The core
idea of TrimTail is to apply length penalty (i.e., by trimming trailing frames,
see Fig. 1-(b)) directly on the spectrogram of input utterances, which does not
require any alignment. We demonstrate that TrimTail is computationally cheap
and can be applied online and optimized with any training loss or any model
architecture on any dataset without any extra effort by applying it on various
end-to-end streaming ASR networks either trained with CTC loss [1] or
Transducer loss [2]. We achieve 100 200ms latency reduction with equal
or even better accuracy on both Aishell-1 and Librispeech. Moreover, by using
TrimTail, we can achieve a 400ms algorithmic improvement of User Sensitive
Delay (USD) with an accuracy loss of less than 0.2.Comment: submitted to ICASSP 202
Taxonomic Distribution of FosB in Human-Microbiota and Activity Comparison of Fosfomycin Resistance
FosB, a Mg2+ dependent thioltransferase, confers antibiotic resistance to fosfomycin through enzymatic drug inactivation. Among all antibiotic resistant proteins in the Antibiotic Resistance Genes Database and the Comprehensive Antibiotic Resistance Database, FosB is within 5% of the most number of ARPs identified in Human Microbiome Project reference database but mainly distributed in limited genera, i.e., 122 of total 133 FosB homologues are found from Bacillus and Staphylococcus. Furthermore, these FosB sequences could be divided into three clusters based on their phylogenetic relationship, i.e., two groups of FosB were mainly from Bacillus, and another was mainly from Staphylococcus. Finally, we confirmed that FosB from the group of Staphylococcus presented the highest resistance ability to fosfomycin by in silico and in vitro comparisons. In summary, this study elaborates the specific taxonomic characteristics and resistant abilities of FosB in human microbiota, which might help in developing more promising fosfomycin-like antibiotics
Bond-Selective Intensity Diffraction Tomography
Recovering molecular information remains a grand challenge in the widely used
holographic and computational imaging technologies. To address this challenge,
we developed a computational mid-infrared photothermal microscope, termed
Bond-selective Intensity Diffraction Tomography (BS-IDT). Based on a low-cost
brightfield microscope with an add-on pulsed light source, BS-IDT recovers both
infrared spectra and bond-selective 3D refractive index maps from
intensity-only measurements. High-fidelity infrared fingerprint spectra
extraction is validated. Volumetric chemical imaging of biological cells is
demonstrated at a speed of ~20 seconds per volume, with a lateral and axial
resolution of ~350 nm and ~1.1 micron, respectively. BS-IDT's application
potential is investigated by chemically quantifying lipids stored in cancer
cells and volumetric chemical imaging on Caenorhabditis elegans with a large
field of view (~100 micron X 100 micron)
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