Wei, Kai
Toward Equitable Access: Leveraging Crowdsourced Reviews to Investigate Public Perceptions of Health Resource Accessibility
Xue, Zhaoqian, Liu, Guanhong, Wei, Kai, Zhang, Chong, Zeng, Qingcheng, Hu, Songhua, Hua, Wenyue, Fan, Lizhou, Zhang, Yongfeng, Li, Lingyao
Access to health resources is a critical determinant of public well-being and societal resilience, particularly during public health crises when demand for medical services and preventive care surges. However, disparities in accessibility persist across demographic and geographic groups, raising concerns about equity. Traditional survey methods often fall short due to limitations in coverage, cost, and timeliness. This study leverages crowdsourced data from Google Maps reviews, applying advanced natural language processing techniques, specifically ModernBERT, to extract insights on public perceptions of health resource accessibility in the United States during the COVID-19 pandemic. Additionally, we employ Partial Least Squares regression to examine the relationship between accessibility perceptions and key socioeconomic and demographic factors including political affiliation, racial composition, and educational attainment. Our findings reveal that public perceptions of health resource accessibility varied significantly across the U.S., with disparities peaking during the pandemic and slightly easing post-crisis. Political affiliation, racial demographics, and education levels emerged as key factors shaping these perceptions. These findings underscore the need for targeted interventions and policy measures to address inequities, fostering a more inclusive healthcare infrastructure that can better withstand future public health challenges.
End-to-end spoken language understanding using joint CTC loss and self-supervised, pretrained acoustic encoders
Wang, Jixuan, Radfar, Martin, Wei, Kai, Chung, Clement
It is challenging to extract semantic meanings directly from The limitation of the above approaches is that they cannot audio signals in spoken language understanding (SLU), due be used for sequence labeling tasks, like slot filling. To address to the lack of textual information. Popular end-to-end (E2E) this issue, another stream of works build unified models, SLU models utilize sequence-to-sequence automatic speech which can be trained end-to-end and used for both intent recognition (ASR) models to extract textual embeddings as classification and slot filling. One way to achieve E2E training input to infer semantics, which, however, require computationally is to re-frame SLU as a sequence-to-sequence task, where expensive auto-regressive decoding. In this work, semantic labels are treated as another sequence of output labels we leverage self-supervised acoustic encoders fine-tuned besides the transcript [9-12]. Another way is to unify with Connectionist Temporal Classification (CTC) to extract ASR and NLU models and train them together via differentiable textual embeddings and use joint CTC and SLU losses for neural interfaces [13-16]. One commonly used neural utterance-level SLU tasks. Experiments show that our model interface is to feed the token level hidden representations from achieves 4% absolute improvement over the the state-of-theart ASR as input to the NLU model [13-16].
Dialog act guided contextual adapter for personalized speech recognition
Chang, Feng-Ju, Muniyappa, Thejaswi, Sathyendra, Kanthashree Mysore, Wei, Kai, Strimel, Grant P., McGowan, Ross
Personalization in multi-turn dialogs has been a long standing challenge for end-to-end automatic speech recognition (E2E ASR) models. Recent work on contextual adapters has tackled rare word recognition using user catalogs. This adaptation, however, does not incorporate an important cue, the dialog act, which is available in a multi-turn dialog scenario. In this work, we propose a dialog act guided contextual adapter network. Specifically, it leverages dialog acts to select the most relevant user catalogs and creates queries based on both -- the audio as well as the semantic relationship between the carrier phrase and user catalogs to better guide the contextual biasing. On industrial voice assistant datasets, our model outperforms both the baselines - dialog act encoder-only model, and the contextual adaptation, leading to the most improvement over the no-context model: 58% average relative word error rate reduction (WERR) in the multi-turn dialog scenario, in comparison to the prior-art contextual adapter, which has achieved 39% WERR over the no-context model.
Attentive Contextual Carryover for Multi-Turn End-to-End Spoken Language Understanding
Wei, Kai, Tran, Thanh, Chang, Feng-Ju, Sathyendra, Kanthashree Mysore, Muniyappa, Thejaswi, Liu, Jing, Raju, Anirudh, McGowan, Ross, Susanj, Nathan, Rastrow, Ariya, Strimel, Grant P.
Recent years have seen significant advances in end-to-end (E2E) spoken language understanding (SLU) systems, which directly predict intents and slots from spoken audio. While dialogue history has been exploited to improve conventional text-based natural language understanding systems, current E2E SLU approaches have not yet incorporated such critical contextual signals in multi-turn and task-oriented dialogues. In this work, we propose a contextual E2E SLU model architecture that uses a multi-head attention mechanism over encoded previous utterances and dialogue acts (actions taken by the voice assistant) of a multi-turn dialogue. We detail alternative methods to integrate these contexts into the state-ofthe-art recurrent and transformer-based models. When applied to a large de-identified dataset of utterances collected by a voice assistant, our method reduces average word and semantic error rates by 10.8% and 12.6%, respectively. We also present results on a publicly available dataset and show that our method significantly improves performance over a noncontextual baseline
Encoding Syntactic Knowledge in Transformer Encoder for Intent Detection and Slot Filling
Wang, Jixuan, Wei, Kai, Radfar, Martin, Zhang, Weiwei, Chung, Clement
We propose a novel Transformer encoder-based architecture with syntactical knowledge encoded for intent detection and slot filling. Specifically, we encode syntactic knowledge into the Transformer encoder by jointly training it to predict syntactic parse ancestors and part-of-speech of each token via multi-task learning. Our model is based on self-attention and feed-forward layers and does not require external syntactic information to be available at inference time. Experiments show that on two benchmark datasets, our models with only two Transformer encoder layers achieve state-of-the-art results. Compared to the previously best performed model without pre-training, our models achieve absolute F1 score and accuracy improvement of 1.59% and 0.85% for slot filling and intent detection on the SNIPS dataset, respectively. Our models also achieve absolute F1 score and accuracy improvement of 0.1% and 0.34% for slot filling and intent detection on the ATIS dataset, respectively, over the previously best performed model. Furthermore, the visualization of the self-attention weights illustrates the benefits of incorporating syntactic information during training.
Jensen: An Easily-Extensible C++ Toolkit for Production-Level Machine Learning and Convex Optimization
Iyer, Rishabh, Halloran, John T., Wei, Kai
This paper introduces Jensen, an easily extensible and scalable toolkit for production-level machine learning and convex optimization. Jensen implements a framework of convex (or loss) functions, convex optimization algorithms (including Gradient Descent, L-BFGS, Stochastic Gradient Descent, Conjugate Gradient, etc.), and a family of machine learning classifiers and regressors (Logistic Regression, SVMs, Least Square Regression, etc.). This framework makes it possible to deploy and train models with a few lines of code, and also extend and build upon this by integrating new loss functions and optimization algorithms.
Modeling and Simultaneously Removing Bias via Adversarial Neural Networks
Moore, John, Pfeiffer, Joel, Wei, Kai, Iyer, Rishabh, Charles, Denis, Gilad-Bachrach, Ran, Boyles, Levi, Manavoglu, Eren
In real world systems, the predictions of deployed Machine Learned models affect the training data available to build subsequent models. This introduces a bias in the training data that needs to be addressed. Existing solutions to this problem attempt to resolve the problem by either casting this in the reinforcement learning framework or by quantifying the bias and re-weighting the loss functions. In this work, we develop a novel Adversarial Neural Network (ANN) model, an alternative approach which creates a representation of the data that is invariant to the bias. We take the Paid Search auction as our working example and ad display position features as the confounding features for this setting. We show the success of this approach empirically on both synthetic data as well as real world paid search auction data from a major search engine.
Mixed Robust/Average Submodular Partitioning: Fast Algorithms, Guarantees, and Applications
Wei, Kai, Iyer, Rishabh K., Wang, Shengjie, Bai, Wenruo, Bilmes, Jeff A.
We investigate two novel mixed robust/average-case submodular data partitioning problems that we collectively call Submodular Partitioning. These problems generalize purelyrobust instances of the problem, namely max-min submodular fair allocation (SFA) [12] and min-max submodular load balancing (SLB) [25], and also average-case instances, that is the submodular welfare problem (SWP) [26] and submodular multiway partition (SMP) [5]. While the robust versions have been studied in the theory community [11, 12, 16, 25, 26], existing work has focused on tight approximation guarantees, and the resultant algorithms are not generally scalable to large real-world applications. This is in contrast to the average case, where most of the algorithms are scalable. In the present paper, we bridge this gap, by proposing several new algorithms (including greedy, majorization-minimization, minorization-maximization, and relaxation algorithms) that not only scale to large datasets but that also achieve theoretical approximation guarantees comparable to the state-of-the-art. We moreover provide new scalable algorithms that apply to additive combinations of the robust and average-case objectives. We show that these problems have many applications in machine learning (ML), including data partitioning and load balancing for distributed ML, data clustering, and image segmentation. Weempirically demonstrate the efficacy of our algorithms on real-world problems involving data partitioning for distributed optimization (of convex and deep neural network objectives), and also purely unsupervised image segmentation.