12,798 research outputs found
Mining large-scale human mobility data for long-term crime prediction
Traditional crime prediction models based on census data are limited, as they
fail to capture the complexity and dynamics of human activity. With the rise of
ubiquitous computing, there is the opportunity to improve such models with data
that make for better proxies of human presence in cities. In this paper, we
leverage large human mobility data to craft an extensive set of features for
crime prediction, as informed by theories in criminology and urban studies. We
employ averaging and boosting ensemble techniques from machine learning, to
investigate their power in predicting yearly counts for different types of
crimes occurring in New York City at census tract level. Our study shows that
spatial and spatio-temporal features derived from Foursquare venues and
checkins, subway rides, and taxi rides, improve the baseline models relying on
census and POI data. The proposed models achieve absolute R^2 metrics of up to
65% (on a geographical out-of-sample test set) and up to 89% (on a temporal
out-of-sample test set). This proves that, next to the residential population
of an area, the ambient population there is strongly predictive of the area's
crime levels. We deep-dive into the main crime categories, and find that the
predictive gain of the human dynamics features varies across crime types: such
features bring the biggest boost in case of grand larcenies, whereas assaults
are already well predicted by the census features. Furthermore, we identify and
discuss top predictive features for the main crime categories. These results
offer valuable insights for those responsible for urban policy or law
enforcement
Geo-Adaptive Deep Spatio-Temporal predictive modeling for human mobility
Deep learning approaches for spatio-temporal prediction problems such as
crowd-flow prediction assumes data to be of fixed and regular shaped tensor and
face challenges of handling irregular, sparse data tensor. This poses
limitations in use-case scenarios such as predicting visit counts of
individuals' for a given spatial area at a particular temporal resolution using
raster/image format representation of the geographical region, since the
movement patterns of an individual can be largely restricted and localized to a
certain part of the raster. Additionally, current deep-learning approaches for
solving such problem doesn't account for the geographical awareness of a region
while modelling the spatio-temporal movement patterns of an individual. To
address these limitations, there is a need to develop a novel strategy and
modeling approach that can handle both sparse, irregular data while
incorporating geo-awareness in the model. In this paper, we make use of
quadtree as the data structure for representing the image and introduce a novel
geo-aware enabled deep learning layer, GA-ConvLSTM that performs the
convolution operation based on a novel geo-aware module based on quadtree data
structure for incorporating spatial dependencies while maintaining the
recurrent mechanism for accounting for temporal dependencies. We present this
approach in the context of the problem of predicting spatial behaviors of an
individual (e.g., frequent visits to specific locations) through deep-learning
based predictive model, GADST-Predict. Experimental results on two GPS based
trace data shows that the proposed method is effective in handling frequency
visits over different use-cases with considerable high accuracy
- …