Automatic human activity recognition systems aim to capture the state of the user and its environment by exploiting heterogeneous sensors attached to the subject's body and permit continuous monitoring of numerous physiological signals reflecting the state of human actions. Successful identification of human activities can be immensely useful in healthcare applications for Ambient Assisted Livi...

We go beyond the notion of pairwise similarity and look into search problems with k-way similarity functions. In this paper, we focus on problems related to 3-way Jaccard similarity: R = |S1∩S2∩S3| |S1∪S2∪S3| , S1, S2, S3 ∈ C, where C is a size n collection of sets (or binary vectors). We show that approximate R similarity search problems admit fast algorithms with provable guarantees, analogou...

Data variety, as one of the three Vs of the Big Data, is man-ifested by a growing number of complex data types such asdocuments, sequences, trees, graphs and high dimensionalvectors. To perform similarity search on these data, exist-ing works mainly choose to create customized indexes fordifferent data types. Due to the diversity of customized in-dexes, it is hard to dev...

A identificação de relações semânticas, expressas entre entidades mencionadas em textos, é um passo importante para a extracção automática de conhecimento a partir de grandes colecções de documentos, tais como a Web. Vários trabalhos anteriores abordaram esta tarefa para o caso da ĺıngua inglesa, usando técnicas de aprendizagem automática supervisionada para classificação de relações, sendo que...