Keyword spotting (KWS) based on deep neural networks (DNNs) has achieved massive success in voice control scenarios. However, training of such DNN-based KWS systems often requires significant data and hardware resources. Manufacturers often entrust this process to a third-party platform. This makes the training process uncontrollable, where attackers can implant backdoors in the model by manipulating third-party training data. An effective backdoor attack can force the model to make specified judgments under certain conditions, i.e., triggers. In this paper, we design a backdoor attack scheme based on Voiceprint Selection and Voice Conversion, abbreviated as VSVC. Experimental results demonstrated that VSVC is feasible to achieve an average attack success rate close to 97% in four victim models when poisoning less than 1% of the training data.

Continual Learning, also known as Lifelong or Incremental Learning, has recently gained renewed interest among the Artificial Intelligence research community. Recent research efforts have quickly led to the design of novel algorithms able to reduce the impact of the catastrophic forgetting phenomenon in deep neural networks. Due to this surge of interest in the field, many competitions have been held in recent years, as they are an excellent opportunity to stimulate research in promising directions. This paper summarizes the ideas, design choices, rules, and results of the challenge held at the 3rd Continual Learning in Computer Vision (CLVision) Workshop at CVPR 2022. The focus of this competition is the complex continual object detection task, which is still underexplored in literature compared to classification tasks. The challenge is based on the challenge version of the novel EgoObjects dataset, a large-scale egocentric object dataset explicitly designed to benchmark continual learning algorithms for egocentric category-/instance-level object understanding, which covers more than 1k unique main objects and 250+ categories in around 100k video frames.

Knowledge distillation is often used to transfer knowledge from a strong teacher model to a relatively weak student model. Traditional knowledge distillation methods include response-based methods and feature-based methods. Response-based methods are used the most widely but suffer from lower upper limit of model performance, while feature-based methods have constraints on the vocabularies and tokenizers. In this paper, we propose a tokenizer-free method liberal feature-based distillation (LEAD). LEAD aligns the distribution between teacher model and student model, which is effective, extendable, portable and has no requirements on vocabularies, tokenizer, or model architecture. Extensive experiments show the effectiveness of LEAD on several widely-used benchmarks, including MS MARCO Passage, TREC Passage 19, TREC Passage 20, MS MARCO Document, TREC Document 19 and TREC Document 20.

While many systems have been developed to train Graph Neural Networks (GNNs), efficient model inference and evaluation remain to be addressed. For instance, using the widely adopted node-wise approach, model evaluation can account for up to 94% of the time in the end-to-end training process due to neighbor explosion, which means that a node accesses its multi-hop neighbors. On the other hand, layer-wise inference avoids the neighbor explosion problem by conducting inference layer by layer such that the nodes only need their one-hop neighbors in each layer. However, implementing layer-wise inference requires substantial engineering efforts because users need to manually decompose a GNN model into layers for computation and split workload into batches to fit into device memory. In this paper, we develop Deep Graph Inference (DGI) -- a system for easy and efficient GNN model inference, which automatically translates the training code of a GNN model for layer-wise execution. DGI is general for various GNN models and different kinds of inference requests, and supports out-of-core execution on large graphs that cannot fit in CPU memory. Experimental results show that DGI consistently outperforms layer-wise inference across different datasets and hardware settings, and the speedup can be over 1,000x.

Aspect-based sentiment analysis (ABSA) aims at extracting opinionated aspect terms in review texts and determining their sentiment polarities, which is widely studied in both academia and industry. As a fine-grained classification task, the annotation cost is extremely high. Domain adaptation is a popular solution to alleviate the data deficiency issue in new domains by transferring common knowledge across domains. Most cross-domain ABSA studies are based on structure correspondence learning (SCL), and use pivot features to construct auxiliary tasks for narrowing down the gap between domains. However, their pivot-based auxiliary tasks can only transfer knowledge of aspect terms but not sentiment, limiting the performance of existing models. In this work, we propose a novel Syntax-guided Domain Adaptation Model, named SDAM, for more effective cross-domain ABSA. SDAM exploits syntactic structure similarities for building pseudo training instances, during which aspect terms of target domain are explicitly related to sentiment polarities. Besides, we propose a syntax-based BERT mask language model for further capturing domain-invariant features. Finally, to alleviate the sentiment inconsistency issue in multi-gram aspect terms, we introduce a span-based joint aspect term and sentiment analysis module into the cross-domain End2End ABSA. Experiments on five benchmark datasets show that our model consistently outperforms the state-of-the-art baselines with respect to Micro-F1 metric for the cross-domain End2End ABSA task.

Video super-resolution is one of the most popular tasks on mobile devices, being widely used for an automatic improvement of low-bitrate and low-resolution video streams. While numerous solutions have been proposed for this problem, they are usually quite computationally demanding, demonstrating low FPS rates and power efficiency on mobile devices. In this Mobile AI challenge, we address this problem and propose the participants to design an end-to-end real-time video super-resolution solution for mobile NPUs optimized for low energy consumption. The participants were provided with the REDS training dataset containing video sequences for a 4X video upscaling task. The runtime and power efficiency of all models was evaluated on the powerful MediaTek Dimensity 9000 platform with a dedicated AI processing unit capable of accelerating floating-point and quantized neural networks. All proposed solutions are fully compatible with the above NPU, demonstrating an up to 500 FPS rate and 0.2 [Watt / 30 FPS] power consumption. A detailed description of all models developed in the challenge is provided in this paper.

Deep learning methods have contributed substantially to the rapid advancement of medical image segmentation, the quality of which relies on the suitable design of loss functions. Popular loss functions, including the cross-entropy and dice losses, often fall short of boundary detection, thereby limiting high-resolution downstream applications such as automated diagnoses and procedures. We developed a novel loss function that is tailored to reflect the boundary information to enhance the boundary detection. As the contrast between segmentation and background regions along the classification boundary naturally induces heterogeneity over the pixels, we propose the piece-wise two-sample t-test augmented (PTA) loss that is infused with the statistical test for such heterogeneity. We demonstrate the improved boundary detection power of the PTA loss compared to benchmark losses without a t-test component.

卷积神经网络可以在语义细分任务中实现出色的性能。但是，这种神经网络方法在很大程度上依赖于昂贵的像素级注释。半监督学习是解决这个问题的有前途的决议，但其表现仍然远远落后于完全受监督的对手。这项工作提出了一个带有三个模块的跨教师培训框架，可显着改善传统的半监督学习方法。核心是跨教师模块，可以同时减少同伴网络之间的耦合以及教师和学生网络之间的错误积累。此外，我们提出了两个互补的对比学习模块。高级模块可以将高质量的知识从标记的数据传输到未标记的数据，并在特征空间中促进类之间的分离。低级模块可以鼓励从同伴网络中的高质量功能学习的低质量功能。在实验中，跨教师模块显着提高了传统的学生教师方法的性能，而我们的框架在基准数据集上的表现优于现行方法。我们的CTT源代码将发布。

作为第一个会话级的中文数据集，Chase包含两个单独的部分，即从Scratch（Chase-C）手动构建的2,003个会话，以及从英语SPARC（Chase-T）翻译的3,456个会话。我们发现这两个部分是高度差异，并且作为培训和评估数据不兼容。在这项工作中，我们介绍了SESQL，这是中文的另一个大规模会话级文本到SQL数据集，由5,028个会话组成，所有课程都是从Scratch手动构建的。为了保证数据质量，我们采用迭代注释工作流程，以促进对先前的自然语言（NL）问题和SQL查询的紧张和及时审查。此外，通过完成所有与上下文有关的NL问题，我们获得了27,012个独立的问题/SQL对，允许SESQL用作单轮多DB文本到SQL解析的最大数据集。我们通过使用三个竞争性会话级解析器，并提供详细的分析，对SESQL进行基准测试级文本到SQL解析实验。

我们提出了一个新颖的范式，该范式是通过单眼视频输入来构建可动画的3D人类代表，以便可以以任何看不见的姿势和观点呈现。我们的方法基于由基于网格的参数3D人类模型操纵的动态神经辐射场（NERF），该模型用作几何代理。以前的方法通常依靠多视频视频或准确的3D几何信息作为其他输入；此外，大多数方法在概括地看不见的姿势时会降解质量。我们确定概括的关键是查询动态NERF的良好输入嵌入：良好的输入嵌入应定义完整量化空间中的注入映射，并在姿势变化下表面网格变形引导。基于此观察结果，我们建议将输入查询嵌入其与局部表面区域的关系，并在网格顶点上跨越一组地球的最近邻居跨越。通过包括位置和相对距离信息，我们的嵌入式定义了距离保存的变形映射，并可以很好地概括为看不见的姿势。为了减少对其他输入的依赖性，我们首先使用现成的工具初始化人均3D网格，然后提出一条管道以共同优化NERF并完善初始网格。广泛的实验表明，我们的方法可以在看不见的姿势和观点下合成合理的人类渲染结果。