Self-Distillation Network with Ensemble Prototypes: Learning Robust Speaker Representations without Supervision

Training speaker-discriminative and robust speaker verification systems without speaker labels is still challenging and worthwhile to explore. Previous studies have noted a substantial performance disparity between self-supervised and fully supervised approaches. In this paper, we propose an effective Self-Distillation network with Ensemble Prototypes (SDEP) to facilitate self-supervised speaker representation learning. A range of experiments conducted on the VoxCeleb datasets demonstrate the superiority of the SDEP framework in speaker verification. SDEP achieves a new SOTA on Voxceleb1 speaker verification evaluation benchmark ( i.e., equal error rate 1.94\%, 1.99\%, and 3.77\% for trial Vox1-O, Vox1-E and Vox1-H , respectively), discarding any speaker labels in the training phase. Code will be publicly available at https://github.com/alibaba-damo-academy/3D-Speaker.Comment: arXiv admin note: text overlap with arXiv:2211.0416

Small-scale assessment of corrosion-induced damage in hardmetals

In this work, the effect of corrosion-induced damage on the mechanical response of hardmetals was evaluated at small-scale level by means of nanoindentation and nanoscratch. Damage was introduced in a controlled way through immersion in acidic solution. It is found that surface degradation associated with corrosion leads to a strong reduction of hardness and elastic modulus, as compared to non-corroded samples. Similarly, significant differences are observed in nanoscratch response, regarding not only width and depth of tracks but also deformation mechanisms developed as contact load is progressively increased. Damage was already evidenced in corroded surfaces at scratching loads one order of magnitude lower than for virgin specimens. Cracking and fragmentation of individual WC grains, together with chipping of at the track edges were the main deformation and fracture micromechanisms identified. Changes in nanoindentation and nanoscratch response and damage scenario are discussed on the basis of the corrosion-induced changes within the intrinsic microstructural assemblage of hardmetals.Postprint (published version

3D-Speaker: A Large-Scale Multi-Device, Multi-Distance, and Multi-Dialect Corpus for Speech Representation Disentanglement

Disentangling uncorrelated information in speech utterances is a crucial research topic within speech community. Different speech-related tasks focus on extracting distinct speech representations while minimizing the affects of other uncorrelated information. We present a large-scale speech corpus to facilitate the research of speech representation disentanglement. 3D-Speaker contains over 10,000 speakers, each of whom are simultaneously recorded by multiple Devices, locating at different Distances, and some speakers are speaking multiple Dialects. The controlled combinations of multi-dimensional audio data yield a matrix of a diverse blend of speech representation entanglement, thereby motivating intriguing methods to untangle them. The multi-domain nature of 3D-Speaker also makes it a suitable resource to evaluate large universal speech models and experiment methods of out-of-domain learning and self-supervised learning. https://3dspeaker.github.io

Pushing the limits of self-supervised speaker verification using regularized distillation framework

Training robust speaker verification systems without speaker labels has long been a challenging task. Previous studies observed a large performance gap between self-supervised and fully supervised methods. In this paper, we apply a non-contrastive self-supervised learning framework called DIstillation with NO labels (DINO) and propose two regularization terms applied to embeddings in DINO. One regularization term guarantees the diversity of the embeddings, while the other regularization term decorrelates the variables of each embedding. The effectiveness of various data augmentation techniques are explored, on both time and frequency domain. A range of experiments conducted on the VoxCeleb datasets demonstrate the superiority of the regularized DINO framework in speaker verification. Our method achieves the state-of-the-art speaker verification performance under a single-stage self-supervised setting on VoxCeleb. The codes will be made publicly-available

Using polysaccharides for the enhancement of functionality of foods: A review

peer-reviewedBackground: Flavor, taste and functional ingredients are important ingredients of food, but they are easily lost or react during heating and are not stable. Carbohydrate-carbohydrate interactions (CCIs) and carbohydrate-protein interactions (CPIs) are involved in a variety of regulatory biological processes in nature, including cell differentiation, proliferation, adhesion, inflammation and immune responses. Polysaccharides have high molecular weights and many intramolecular hydrogen bonds, can be easily modified chemically and biochemically to enhance bioadhesive and biostability of tissues. Therefore, polysaccharides are the foundation for building complex and stable biosystems that are non-toxic with highydrophilicity and easily biodegradable. Scope and approach: In this review, we summarize the principles and applications of polysaccharide delivery systems in a variety of foods. Key findings and conclusions: This review focuses on the self-assembly of carbohydrates with complex structures and discusses the latest advances in self-assembly systems. The host-guest complexes formed by polyvalent sugar conjugates have the potential to provide, control or target delivery or release systems. They can also extend the shelf life of food and prevent oxidation and isomerization during food storage. Moreover, very few studies have outlined a comprehensive overview of the use of various types of food polysaccharide matrixes for the assembly and protection of food ingredients, which is a very important area for further study

A Novel Diffusion-Permutation Image Encryption Scheme Based on Spatiotemporal Chaos

The spatiotemporal chaos possesses better properties than simple chaotic system, which has attracted more and more attention by the researchers in the image encryption field. This paper presents a novel image encryption scheme based on spatiotemporal chaos. The algorithm uses the spatiotemporal chaos to diffuse plain image and an Arnold map shuffle the positions of pixels. Test results and security analysis not only show that the scheme is characteristic of excellent sensitivity to the original image and keys, large secret key space and high expansibility, but also has excellent effective encryption and strong anti-attacking performance

Corrosion-induced changes on Hertzian contact damage in cemented carbides

In this study, the influence of corrosion on the mechanical response and damage induced under Hertzian indentation is assessed for three cemented carbides with metallic binders of different chemical nature. Corrosion degradation is introduced in a controlled way, before subsequent spherical indentation testing, by immersing specimens in a stirred acidic medium. Results reveal quite strong corrosion effects on indentation stress-strain response and contact damage scenario. Such detrimental influence is found to be dependent on both the ratio between indentation depth and thickness of the corroded layer as well as chemical nature of the binder. In this regard, critical loads for emergence and evolution of specific damage events (i.e. ring and radial cracks, and even specimen failure) are proposed as figures of merit for material selection under the combined action of corrosion and contact loads. Within this context, the hardmetal grade with Co-base binder and addition of Cr is found to be the best option, among the three cemented carbides studied in this investigation. It points out the consideration of the synergic interaction between corrosion resistance and hardness/toughness correlation for microstructural design optimization of hardmetals under service-like conditions. These statements are supported by the relevant corrosion-induced changes also observed, by means of advanced characterization techniques, in terms of deformation/failure micromechanisms at both surface and subsurface levels.Peer ReviewedPostprint (author's final draft

Improving Speaker Diarization using Semantic Information: Joint Pairwise Constraints Propagation

Speaker diarization has gained considerable attention within speech processing research community. Mainstream speaker diarization rely primarily on speakers' voice characteristics extracted from acoustic signals and often overlook the potential of semantic information. Considering the fact that speech signals can efficiently convey the content of a speech, it is of our interest to fully exploit these semantic cues utilizing language models. In this work we propose a novel approach to effectively leverage semantic information in clustering-based speaker diarization systems. Firstly, we introduce spoken language understanding modules to extract speaker-related semantic information and utilize these information to construct pairwise constraints. Secondly, we present a novel framework to integrate these constraints into the speaker diarization pipeline, enhancing the performance of the entire system. Extensive experiments conducted on the public dataset demonstrate the consistent superiority of our proposed approach over acoustic-only speaker diarization systems.Comment: Submitted to ICASSP 202

Production of Squalene in Bacillus subtilis by Squalene Synthase Screening and Metabolic Engineering

Squalene synthase (SQS) catalyzes the conversion of two farnesyl pyrophosphates to squalene, an important intermediate in between isoprene and valuable triterpenoids. In this study, we have constructed a novel biosynthesis pathway for squalene in Bacillus subtilis and performed metabolic engineering aiming at facilitating further exploitation and production of squalene-derived triterpenoids. Therefore, systematic studies and analysis were performed including selection of multiple SQS candidates from various organisms, comparison of expression vectors, optimization of cultivation temperatures, and examination of rate-limiting factors within the synthetic pathway. We were, for the first time, able to obtain squalene synthesis in B. subtilis. Furthermore, we achieved a 29-fold increase of squalene yield (0.26-7.5 mg/L) by expressing SQS from Bacillus megaterium and eliminating bottlenecks within the upstream methylerythritol-phosphate pathway. Moreover, our findings showed that also ispA could positively affect the production of squalene

Influence of corrosion-induced damage on mechanical integrity and load-bearing capability of cemented carbides

Tungsten carbide based cemented carbides, often simply termed hardmetals, are established forefront materials for tools, structural components, and wear parts with stringent requirements. Several of the technological applications in which they are used include exposure to chemically aggressive media. Under these conditions, failure induced under applied load may be accelerated; and consequently, the service life may be decreased. Within this context, this work addresses the influence of corrosion-induced damage on the mechanical integrity and load-bearing capability of hardmetals at different length scales, i.e., from 100s nanometers to 1000s microns. Experimental data acquired by means of nanoindentation, pyramidal, and spherical indentation, as well as sliding contact (micro- and nanoscratch) techniques, are presented. The attained results allow for identifying guidelines for the microstructural design of these materials under combined consideration of corrosion and mechanical contact as service-like conditions. Discussion of the reported findings includes a critical analysis of corrosion effects on the evolution of microstructure-property-performance interrelations for the materials under consideration.Peer ReviewedPostprint (published version