To provide effective services for intelligent transportation systems (ITS), such as optimizing ride services and recommending trips, it is important to predict the distributions of passenger flows from various origins to destinations. However, existing crowd flow prediction models have not sufficiently addressed this problem, and most methods have only focused on in and out flows of individual regions. The main challenges of origin-destination (OD) crowd flow prediction are diverse flow patterns across city networks and data sparsity. To solve these problems, we propose a Multi Attention 3D Residual Network (MAThR) to predict city-wide OD crowd flows. In particular, we develop a multi-component 3D residual structure with a novel global self-attention mechanism to dynamically aggregate the OD spatial-temporal dependencies, by modeling three components: contextual information of the region, and long and short term periodic crowd flows. For each component, we design a tensor criss-cross self-attention block, which can simultaneously discover the global and local correlation of spatial (where), temporal (when) and contextual (which) information between all OD pairs. Evaluation on real-world crowd flow data demonstrates the advantages of our MAThR method on prediction accuracy, compared to other existing state-of-the-art methods.

The problem of learning a discrimination aware model has recently received attention in the data mining community. Various methods and improved models have been proposed, with the main approach being the detection of a discrimination sensitive attribute. Once the discrimination sensitive attribute is identified, the methods aim to develop a strategy that will include the useful information from that attribute without causing any additional discrimination. Our work focuses on an aspect often overlooked in the discrimination aware classification - the scenario of an imbalanced dataset, where the number of samples from one class is disproportionate to the other. We also investigate a strategy that is directly minimizing discrimination and is independent of the class balance. Our empirical results indicate additional concerns that need to be considered when developing discrimination aware classifiers, and our proposed strategy shows promise in overcoming these concerns.

Support Vector Machines (SVMs) are a leading tool in machine learning and have been used with considerable success for the task of time series forecasting. However, a key challenge when using SVMs for time series is the question of how to deeply integrate time elements into the learning process. To address this challenge, we investigated the distribution of errors in the forecasts delivered by standard SVMs. Once we identified the samples that produced the largest errors, we observed their correlation with distribution shifts that occur in the time series. This motivated us to propose a time-dependent loss function which allows the inclusion of the information about the distribution shifts in the series directly into the SVM learning process. We present experimental results which indicate that using a time-dependent loss function is highly promising, reducing the overall variance of the errors, as well as delivering more accurate predictions.