Temporal Sentence Grounding in Video (TSGV) is troubled by dataset bias issue, which is caused by the uneven temporal distribution of the target moments for samples with similar semantic components in input videos or query texts. Existing methods resort to utilizing prior knowledge about bias to artificially break this uneven distribution, which only removes a limited amount of significant language biases. In this work, we propose the bias-conflict sample synthesis and adversarial removal debias strategy (BSSARD), which dynamically generates bias-conflict samples by explicitly leveraging potentially spurious correlations between single-modality features and the temporal position of the target moments. Through adversarial training, its bias generators continuously introduce biases and generate bias-conflict samples to deceive its grounding model. Meanwhile, the grounding model continuously eliminates the introduced biases, which requires it to model multi-modality alignment information. BSSARD will cover most kinds of coupling relationships and disrupt language and visual biases simultaneously. Extensive experiments on Charades-CD and ActivityNet-CD demonstrate the promising debiasing capability of BSSARD. Source codes are available at https://github.com/qzhb/BSSARD.

Temporal sentence grounding in video has witnessed significant advancements, but suffers from substantial dataset bias, which undermines its generalization ability. Existing debias approaches primarily concentrate on well-known distribution and linguistic biases, while overlooking the relationship among different biases, limiting their debias capability. In this work, we delve into the existence of visual bias and combinatorial bias in the widely used datasets, and introduce a collaborative debias structure that can be seamlessly integrated into present methods. It encompasses four low-capacity models, a re-label module, and a main model. Each biased model deliberately leverages bias as shortcut information to accurately perform grounding, achieved by customizing the appropriate model structure and input data format to align with the bias characteristics. During the training phase, the gradient descent direction for optimizing the main model should align with the negative gradient descent direction of the biased model that is optimized by utilizing ground truth labels. Subsequently, the re-label module introduces a gradient aggregation function, consolidating the gradient descent direction from these biased models and constructing new labels to compel the main model to effectively capture multi-modality alignment features instead of relying on shortcut contents for grounding. Finally, we design two debias structures, P-Debias and C-Debias, to exploit the independence and inclusion relationships between different types of biases. Extensive experiments on multiple span-based models over Charades-CD and ActivityNet-CD demonstrate the exceptional debias capability of our strategy (https://github.com/qzhb/CDS).

Seasonal influenza epidemics which annually cause substantial diseases and deaths in high-risk population groups are a major public health concern around the world. Considering the hysteresis of traditional flu surveillance systems, this work aims to present a methodology capable of forecasting influenza activity of a city in China precisely 1 week ahead of the official publication. To that end, exogenous information collected from different sources were separately tested with historical influenza-like illness reports for the ability of detecting influenza activity, including climate surveillance, Internet users’ search activity, twitter and health inquiry on an online health consultation platform. Moreover, an ensemble model combining a time series analysis model and a tree boosting model based on those multisource data was applied to improve the accuracy and generalizability of influenza forecasting, in which a model fusion method based on the Kalman Filter was proposed. The validation experiments in this work were performed on the influenza-like illness reports collected from Chongqing city over 4 influenza seasons within 2014–2017. The results show that the proposed model outperformed other tested models by not only taking the periodic law of influenza into consideration but also incorporating information from diverse data sources. The mean absolute percentage error of the validation data set decreased to about 10%. This work provides a viable suggestion for improving the influenza activity forecasting of a city at its early stage.