Real-world applications always contain complex data objects with multiple semantics. The machine learning tasks generalized from these applications can be formulated as multi-instance multi-label learning (MIML) problems. Each object is represented by a bag of multiple instances and can be associated with multiple labels simultaneously. Extensive studies on the MIML have been conducted during the past few years. However, many of them do not consider local label correlations, which is critical in multi-label scenario. To address this problem, we propose the multi-instance multi-label learning based on parallel attention and local label manifold correlation (MIML-LLMC) algorithm. First, parallel multiple attention mechanisms convert each bag into a number of fusion vectors, one for each label. They are also utilized to find out which instances in the bag trigger respective labels to improve explanability. Second, local label manifold correlation vectors (LLMCs) are constructed based on label manifold generation and clustering. They provide a high level of representation of the label vectors. Third, each fusion vector is concatenated to the LLMC to predict each label independently. With the utilization of attention and LLMCs, MIML-LLMC is able to discover instance-label relations and exploit local label correlations simultaneously. Experiments reveal that our approach is highly competitive to the state-of-the-art MIML algorithms and yields reasonable results in understanding the relations between input patterns and output label semantics.

Multi-instance learning (MIL) is more general and challenging than traditional supervised learning in that labels are given at the bag level. The popular feature mapping approaches convert each bag into an instance in the new feature space. However, most of them hardly maintain the distinguishability of bags, and the MIL model does not support self-reinforcement. In this article, we propose the multi-instance ensemble learning with discriminative bags (ELDB) algorithm with two new techniques. The bag selection technique obtains a discriminative bag set (dBagSet) according to two parts. First, considering the space and label distribution of the data, the bag selection process is optimized through discriminative analysis to obtain the basic dBagSet. Second, with the state and action transfer strategy, a dBagSet with better distinguishability is obtained through self-reinforcement. The ensemble technique trains a series of classifiers with these dBagSets and obtains the final weighted model. The experimental results show that ELDB is superior to the state-of-the-art MIL mapping solutions.