Content-Based Unsupervised Fake News Detection on Ukraine-Russia War

The Ukrainian-Russian war has garnered significant attention worldwide, with fake news obstructing the formation of public opinion and disseminating false information. This scholarly paper explores the use of unsupervised learning methods and the Bidirectional Encoder Representations from Transformers (BERT) to detect fake news in news articles from various sources. BERT topic modeling is applied to cluster news articles by their respective topics, followed by summarization to measure the similarity scores. The hypothesis posits that topics with larger variances are more likely to contain fake news. The proposed method was evaluated using a dataset of approximately 1000 labeled news articles related to the Syrian war. The study found that while unsupervised content clustering with topic similarity was insufficient to detect fake news, it demonstrated the prevalence of fake news content and its potential for clustering by topic

Enhancing extractive summarization with automatic post-processing

Tese de doutoramento, Informática (Ciência da Computação), Universidade de Lisboa, Faculdade de Ciências, 2015Any solution or device that may help people to optimize their time in doing productive work is of a great help. The steadily increasing amount of information that must be handled by each person everyday, either in their professional tasks or in their personal life, is becoming harder to be processed. By reducing the texts to be handled, automatic text summarization is a very useful procedure that can help to reduce significantly the amount of time people spend in many of their reading tasks. In the context of handling several texts, dealing with redundancy and focusing on relevant information the major problems to be addressed in automatic multi-document summarization. The most common approach to this task is to build a summary with sentences retrieved from the input texts. This approach is named extractive summarization. The main focus of current research on extractive summarization has been algorithm optimization, striving to enhance the selection of content. However, gains related to the increasing of algorithms complexity have not yet been proved, as the summaries remain difficult to be processed by humans in a satisfactory way. A text built fromdifferent documents by extracting sentences fromthemtends to form a textually fragile sequence of sentences, whose elements tend to be weakly related. In the present work, tasks that modify and relate the summary sentences are combined in a post-processing procedure. These tasks include sentence reduction, paragraph creation and insertion of discourse connectives, seeking to improve the textual quality of the final summary to be delivered to human users. Thus, this dissertation addresses automatic text summarization in a different perspective, by exploring the impact of the postprocessing of extraction-based summaries in order to build fluent and cohesive texts and improved summaries for human usage.Qualquer solução ou dispositivo que possa ajudar as pessoas a optimizar o seu tempo, de forma a realizar tarefas produtivas, é uma grande ajuda. A quantidade de informação que cada pessoa temque manipular, todos os dias, seja no trabalho ou na sua vida pessoal, é difícil de ser processada. Ao comprimir os textos a serem processados, a sumarização automática é uma tarefa muito útil, que pode reduzir significativamente a quantidade de tempo que as pessoas despendem em tarefas de leitura. Lidar com a redundância e focar na informação relevante num conjunto de textos são os principais objectivos da sumarização automática de vários documentos. A abordagem mais comum para esta tarefa consiste em construirse o resumo com frases obtidas a partir dos textos originais. Esta abordagem é conhecida como sumarização extractiva. O principal foco da investigação mais recente sobre sumarização extrativa é a optimização de algoritmos que visam obter o conteúdo relevante expresso nos textos originais. Porém, os ganhos relacionados com o aumento da complexidade destes algoritmos não foram ainda comprovados, já que os sumários continuam a ser difíceis de ler. É expectável que um texto, cujas frases foram extraídas de diferentes fontes, forme uma sequência frágil, sobretudo pela falta de interligação dos seus elementos. No contexto deste trabalho, tarefas que modificam e relacionam frases são combinadas numprocedimento denominado pós-processamento. Estas tarefas incluem a simplificação de frases, a criação de parágrafos e a inserção de conectores de discurso, que juntas procurammelhorar a qualidade do sumário final. Assim, esta dissertação aborda a sumarização automática numa perspectiva diferente, estudando o impacto do pós-processamento de um sumário extractivo, a fim de produzir um texto final fluente e coeso e em vista de se obter uma melhor qualidade textual.Fundação para a Ciência e a Tecnologia (FCT), SFRH/BD/45133/200

Theory and Applications for Advanced Text Mining

Due to the growth of computer technologies and web technologies, we can easily collect and store large amounts of text data. We can believe that the data include useful knowledge. Text mining techniques have been studied aggressively in order to extract the knowledge from the data since late 1990s. Even if many important techniques have been developed, the text mining research field continues to expand for the needs arising from various application fields. This book is composed of 9 chapters introducing advanced text mining techniques. They are various techniques from relation extraction to under or less resourced language. I believe that this book will give new knowledge in the text mining field and help many readers open their new research fields