Improving the text classification using clustering and a novel HMM to reduce the dimensionality

Using hidden Markov model to predict recurrence of breast cancer based on sequential patterns in gene expression profiles

A new approach is presented to predict breast cancer recurrence through gene expression profiles using hidden Markov models (HMM). In this regard, 322 genes were selected from 44 published gene lists related to breast cancer prognosis. Afterwards, using gene set enrichment analysis, 922 gene sets were found from subsets of genes with the same biological meaning. In order to extract the sequential patterns from gene expression data, we ranked the gene sets using appropriate criteria and used HMM in which the ranked gene sets considered as observation sequences and hidden states represented priority of gene sets for discriminating between expression profiles. In this experiment, seven publicly available microarray datasets, including 1271 breast tumor samples, were used to classify cancer patients into two groups according to risk of recurrence. Our experiments indicated the greater performance and more robustness of the proposed model compared with other widely used classification methods.

"I will never go to Hong Kong again!" How the secondary crisis communication of "Occupy Central" on Weibo shifted to a tourism boycott

Social media, an open space for the public's opinion and expression, has become an increasingly essential issue in crisis events, leading to secondary crisis communication. Realizing the potential risk of that, this study took the "Occupy Central" spreading on Weibo as a case, and applied topic clustering and sentiment analysis to examine the sequential characteristics of secondary crisis communication on social media in topics and emotions. Results show that the topics Weibo users discussed shifted from a political event to tourism boycott, with emotions turning increasingly negative. The turning point of such a transfer was aroused group conflicts and negative emotions elicited between people from mainland China and Hong Kong. The results indicate the necessity of emphasizing secondary crisis communication during a crisis due to the dynamic and sequential change of topics and public's emotions, which may result in new crises impacting the tourism destination where the initial crisis occurs.