The Thresholding Bandit (TB) problem is a popular sequential decision-making problem, which aims at identifying the systems whose means are greater than a threshold. Instead of working on the upper bound of a loss function, our approach stands out from conventional practices by directly minimizing the loss itself. Leveraging the large deviation theory, we firstly provide an asymptotically optimal allocation rule for the TB problem, and then propose a parameter-free Large Deviation (LD) algorithm to make the allocation rule implementable. Central limit theorem-based Large Deviation (CLD) algorithm is further proposed as a supplement to improve the computation efficiency using normal approximation. Extensive experiments are conducted to validate the superiority of our algorithms compared to existing methods, and demonstrate their broader applications to more general distributions and various kinds of loss functions.

Disinformation, often known as fake news, is a major issue that has received a lot of attention lately. Many researchers have proposed effective means of detecting and addressing it. Current machine and deep learning based methodologies for classification/detection of fake news are content-based, network (propagation) based, or multimodal methods that combine both textual and visual information. We introduce here a framework, called FNACSPM, based on sequential pattern mining (SPM), for fake news analysis and classification. In this framework, six publicly available datasets, containing a diverse range of fake and real news, and their combination, are first transformed into a proper format. Then, algorithms for SPM are applied to the transformed datasets to extract frequent patterns (and rules) of words, phrases, or linguistic features. The obtained patterns capture distinctive characteristics associated with fake or real news content, providing valuable insights into the underlying structures and commonalities of misinformation. Subsequently, the discovered frequent patterns are used as features for fake news classification. This framework is evaluated with eight classifiers, and their performance is assessed with various metrics. Extensive experiments were performed and obtained results show that FNACSPM outperformed other state-of-the-art approaches for fake news classification, and that it expedites the classification task with high accuracy.