With the prevalence of voice devices in our daily life, speech data is accumulated at an unprecedented speed, forming an invaluable database for security surveillance and financial risk management. In these applications, a key task is given a querying speech snippet to retrieve all speech snippets that are uttered by the same speaker as the querying one, namely Identity-Oriented Speech Retrieval (IO-SR). In this paper, we propose an accuracy and scalable system for IO-SR, which seamlessly integrates speaker modeling and deep indexing techniques. Evaluations on an industrial dataset containing millions of speech snippets show that our system achieves superior performance compared with the state-of-the-art methods.

In order to mine latent semantics from text data, word embedding and topic modeling are two major methodologies in industry. From a pragmatic perspective, each of these two lines of semantic models faces increasing challenges from real-life applications. However, modern text mining tasks typically require a panoramic view of the latent semantics. Hence, discovering heterogeneous semantics (e.g., heterogeneous types of latent topics) is critical for the performance of these tasks, and it is necessary to design a model that meets this demand. Furthermore, with the arrival of the big data era and the increasing awareness of data privacy, it is necessary to study the issues of mining heterogeneous semantics with high efficiency while avoiding compromising data privacy. In this work, we develop a novel method called Heterogeneous Latent Topic Discovery (HLTD) which seamlessly integrates topic modeling with word embedding to discover heterogeneous latent topics. By coupling parameter-server architecture with new private sampling algorithms, HLTD can be efficiently trained with effective protection of underlying data privacy. We evaluate HLTD through a wide range of qualitative and quantitative metrics in industry. Extensive experiments demonstrates the superiority of HLTD over the state-of-the-arts.

Since data regulations such as the European Union's General Data Protection Regulation (GDPR) have taken effect, the traditional two-step Automatic Speech Recognition (ASR) optimization strategy (i.e., training a one-size-fits-all model with vendor's centralized data and fine-tuning the model with clients' private data) has become infeasible. To meet these privacy requirements, TFE, a novel GDPR-compliant ASR ecosystem, has been proposed by us to incorporate transfer learning, federated learning, and evolutionary learning towards effective ASR model optimization. In this demonstration, we further design and implement a novel platform to promote the deployment and applicability of TFE. Our proposed platform allows enterprises to easily conduct the ASR optimization task using TFE across organizations.

We demonstrate a health-friendly speaker verification system for voice-based identity verification on mobile devices. The system is built upon a speech processing module, a ResNet-based local acoustic feature extractor and a multi-head attention-based embedding layer, and is optimized under an additive margin softmax loss for discriminative speaker verification. It is shown that the system achieves superior performance no matter whether there is mask wearing or not. This characteristic is important for speaker verification services operating in regions affected by the raging coronavirus pneumonia. With this demonstration, the audience will have an in-depth experience of how the accuracy of bio-metric verification and the personal health are simultaneously ensured. We wish that this demonstration would boost the development of next-generation bio-metric verification technologies.

Probabilistic topic modeling has been applied in a variety of industrial applications. Training a high-quality model usually requires a massive amount of data to provide comprehensive co-occurrence information for the model to learn. However, industrial data such as medical or financial records are often proprietary or sensitive, which precludes uploading to data centers. Hence, training topic models in industrial scenarios using conventional approaches faces a dilemma: A party (i.e., a company or institute) has to either tolerate data scarcity or sacrifice data privacy. In this article, we propose a framework named Industrial Federated Topic Modeling (iFTM), in which multiple parties collaboratively train a high-quality topic model by simultaneously alleviating data scarcity and maintaining immunity to privacy adversaries. iFTM is inspired by federated learning, supports two representative topic models (i.e., Latent Dirichlet Allocation and SentenceLDA) in industrial applications, and consists of novel techniques such as private Metropolis-Hastings, topic-wise normalization, and heterogeneous model integration. We conduct quantitative evaluations to verify the effectiveness of iFTM and deploy iFTM in two real-life applications to demonstrate its utility. Experimental results verify iFTM’s superiority over conventional topic modeling.

In this paper, a novel Generation-Evaluation framework is developed for multi-turn conversations with the objective of letting both participants know more about each other.For the sake of rational knowledge utilization and coherent conversation flow, a dialogue strategy which controls knowledge selection is instantiated and continuously adapted via reinforcement learning.Under the deployed strategy, knowledge grounded conversations are conducted with two dialogue agents.The generated dialogues are comprehensively evaluated on aspects like informativeness and coherence, which are aligned with our objective and human instinct.These assessments are integrated as a compound reward to guide the evolution of dialogue strategy via policy gradient.Comprehensive experiments have been carried out on the publicly available dataset, demonstrating that the proposed method outperforms the other state-of-the-art approaches significantly.

Though great progress has been made for human-machine conversation, current dialogue system is still in its infancy: it usually converses passively and utters words more as a matter of response, rather than on its own initiatives. In this paper, we take a radical step towards building a human-like conversational agent: endowing it with the ability of proactively leading the conversation (introducing a new topic or maintaining the current topic). To facilitate the development of such conversation systems, we create a new dataset named Konv where one acts as a conversation leader and the other acts as the follower. The leader is provided with a knowledge graph and asked to sequentially change the discussion topics, following the given conversation goal, and meanwhile keep the dialogue as natural and engaging as possible. Konv enables a very challenging task as the model needs to both understand dialogue and plan over the given knowledge graph. We establish baseline results on this dataset (about 270K utterances and 30k dialogues) using several state-of-the-art models. Experimental results show that dialogue models that plan over the knowledge graph can make full use of related knowledge to generate more diverse multi-turn conversations. The baseline systems along with the dataset are publicly available.

End-to-end neural models for intelligent dialogue systems suffer from the problem of generating uninformative responses. Various methods were proposed to generate more informative responses by leveraging external knowledge. However, few previous work has focused on selecting appropriate knowledge in the learning process. The inappropriate selection of knowledge could prohibit the model from learning to make full use of the knowledge. Motivated by this, we propose an end-to-end neural model which employs a novel knowledge selection mechanism where both prior and posterior distributions over knowledge are used to facilitate knowledge selection. Specifically, a posterior distribution over knowledge is inferred from both utterances and responses, and it ensures the appropriate selection of knowledge during the training process. Meanwhile, a prior distribution, which is inferred from utterances only, is used to approximate the posterior distribution so that appropriate knowledge can be selected even without responses during the inference process. Compared with the previous work, our model can better incorporate appropriate knowledge in response generation. Experiments on both automatic and human evaluation verify the superiority of our model over previous baselines.

Topic modeling and word embedding are two important techniques for deriving latent semantics from data. General-purpose topic models typically work in coarse granularity by capturing word co-occurrence at the document/sentence level. In contrast, word embedding models usually work in much finer granularity by modeling word co-occurrence within small sliding windows. With the aim of deriving latent semantics by considering word co-occurrence at different levels of granularity, we propose a novel model named Latent Topic Embedding (LTE), which seamlessly integrates topic generation and embedding learning in one unified framework. We further propose an efficient Monte Carlo EM algorithm to estimate the parameters of interest. By retaining the individual advantages of topic modeling and word embedding, LTE results in better latent topics and word embedding. Extensive experiments verify the superiority of LTE over the state-of-the-arts.