The 21^st ACM SIGSPATIAL Conference on Advances in Geographic Information Systems (GIS) was held in November of 2013 in Orlando, Florida. Following the success of last year's event, we organized the second programming contest associated with the ...

The ACM SIGSPATIAL Cup 2013 is about geo-fencing, a problem of determining whether sampled location points fall inside or within a certain distance from virtual perimeters for real-world geographic areas. This paper describes one of the winning ...

Geo-fencing is a promising technique for emerging location-based services. Its two basic spatial predicates, INSIDE and WITHIN pairings between points and polygons, can be addressed by state-of-the-art methods such as the crossing number algorithm. In ...

This paper describes a point-polygon query program we submitted to the ACM SIGSPATIAL Cup 2013. Point-polygon topological relationship query is one of the core functions for commercial spatial databases, and also an active research topic in academia. ...

A typical online GPS tracking system uses a cellular uplink to report the location of a device to a central server, and in a study based on 1.6 billion location updates we find at least 90% are sent with a fixed 1--300 second period. Through experiments ...

Hidden Markov Models (HMMs) based map matching - that matches a sequence of location samples to a road network - has received a lot of traction in recent years. In this paper we revisit the basic assumption underlying HMM-based map matching algorithms, ...

The positioning datasets that underpin route prediction models arrive as time series or point process logs. However, their use for prediction requires them to be split into meaningful segments, conceptualised as travelling periods or 'journeys', to form ...

Finding the hotspots in large indoor spaces is very important for getting overloaded locations, security, crowd management, indoor navigation and guidance. The tracking data coming from indoor tracking are huge in volume and not readily available for ...

In the last few years the amount of available spatial data has increased both in volume and in heterogeneity, so that dealing with this huge amount of information has become an interesting new research challenge. In particular, spatial data are usually ...

The Radio Frequency Identification (RFID) emerges to be one of the key technologies to modernize object tracking and monitoring systems in indoor environments, e.g., airport baggage tracking. Although RFID has advantages over alternative identification ...

Ordinary navigation systems compute the cost-optimal way to a given destination. However, it is often not possible to directly park the car at the destination of a route. Since parking possibilities are often limited, drivers have to locate a free ...

The process of map matching takes a sequence of possibly noisy GPS coordinates from a vehicle trace and estimates the actual road positions---a crucial first step needed by many GPS applications. There has been a plethora of methods for map matching ...

To a large degree, the attraction of Big Data lies in the variety of its heterogeneous multi-thematic and multi-dimensional data sources and not merely its volume. To fully exploit this variety, however, requires conflation. This is a two step process. ...

Trajectories are used to represent objects' movement and spatio-temporal aggregation of trajectories is commonly used in knowledge discovery. Based on a general workflow to extract knowledge, we identify relevant factors that propagate uncertainty in ...

Monitoring user location updates has important applications in public safety, national security, etc. However, sensitive information can be derived from movement patterns, so user locations must be disclosed only when some condition is met, for instance ...

Most multimedia contain location information whether they are implicit or explicit, and they are very useful for several purposes. In particular, we may use location information in defining query conditions to retrieve relevant multimedia. For this ...

In an effort to bridge the gap between public and personal transportation shared cabs are becoming attractive option, especially in large metropolitan areas. Places that see an aggregation of passengers such as airports and railway stations are well ...

Given a set of points of interest (POIs), the spatial skyline query for a set of locations returns the POIs that are close to all locations. Answering spatial skyline query can find many applications in Geographical Information Systems. In this paper, ...

The general use of mobile sensors equipped with video, GPS, and compass is gaining momentum. These sensors continuously stream geo-referenced videos, which provide enormous amounts of data. Efficiently searching through these long-duration video ...