Geewook Kim, Hodong Lee, Daehee Kim, Haeji Jung, Sanghee Park, Yoonsik Kim, Sangdoo Yun, Taeho Kil, Bado Lee, Seunghyun Park. Proceedings of the 2023 Conference on Empirical Methods in Natural Language Processing. 2023.

Inspired by the great success of language model (LM)-based pre-training, recent studies in visual document understanding have explored LM-based pre-training methods for modeling text within document images. Among them, pre-training that reads all text from an image has shown promise, but often exhibits instability and even fails when applied to broader domains, such as those involving both visual documents and scene text images. This is a substantial limitation for real-world scenarios, where the processing of text image inputs in diverse domains is essential. In this paper, we investigate effective pre-training tasks in the broader domains and also propose a novel pre-training method called SCOB that leverages character-wise supervised contrastive learning with online text rendering to effectively pre-train document and scene text domains by bridging the domain gap. Moreover, SCOB enables weakly supervised learning, significantly reducing annotation costs. Extensive benchmarks demonstrate that SCOB generally improves vanilla pre-training methods and achieves comparable performance to state-of-the-art methods. Our findings suggest that SCOB can be served generally and effectively for read-type pre-training methods. The code will be available at https://github.com/naver-ai/scob.

With the steady growth of the aging population, there has been increasing interest in the health of elderly people. In particular, a physical fall can be fatal for the elderly or result in complications that cause more serious physical and mental damage than the cause of the falls. For this reason, it is important to accurately predict the occurrence of abnormal behavior in advance. Although existing methods can be used to analyze general behavioral characteristics, personalized and customized behavioral prediction remains challenging. In this paper, we propose a customized pre-prediction method using sensor wearers’ biometric information as well as behavioral data reflecting the wearers’ unique behavioral characteristics. The technique is based on a temporal fusion transformers method [1] that can be effectively applied to multi-horizon forecasting. A performance evaluation was made to compare the effects of including and excluding biometric information to quantitatively evaluate the enhancement achieved by extending the prediction model. The use of additional biometric information enabled superior performance with 0.9702, 0.9702, 0.9702, 0.9883 in F-1 score, precision, recall respectively, which is all evaluation indicators. The code for the experiments can be found at the following GitHub address: https://github.com/IKKIM00/Fall_Detection_using_multihorizon_forecasting.

In general, an experimental environment for deep learning assumes that the training and the test dataset are sampled from the same distribution. However, in real-world situations, a difference in the distribution between two datasets, i.e. domain shift, may occur, which becomes a major factor impeding the generalization performance of the model. The research field to solve this problem is called domain generalization, and it alleviates the domain shift problem by extracting domain-invariant features explicitly or implicitly. In recent studies, contrastive learning-based domain generalization approaches have been proposed and achieved high performance. These approaches require sampling of the negative data pair. However, the performance of contrastive learning fundamentally depends on quality and quantity of negative data pairs. To address this issue, we propose a new regularization method for domain generalization based on contrastive learning, called self-supervised contrastive regularization (SelfReg). The proposed approach use only positive data pairs, thus it resolves various problems caused by negative pair sampling. Moreover, we propose a class-specific domain perturbation layer (CDPL), which makes it possible to effectively apply mixup augmentation even when only positive data pairs are used. The experimental results show that the techniques incorporated by SelfReg contributed to the performance in a compatible manner. In the recent benchmark, DomainBed, the proposed method shows comparable performance to the conventional state-of-the-art alternatives.