Bart Moelans

University of Antwerp | UA · Library Department

We study a decision problem, that emerges from the area of spatial reasoning. This decision problem concerns the description of polylines in the plane by means of their double-cross matrix. In such a matrix, the relative position of each pair of line segments in a polyline is expressed by means of a 4-tuple over . However, not any such matrix of 4-...

Location-aware devices can be used to record the positions of moving objects for further spatio-temporal data analysis. For instance, we can analyze the routes followed by a person or a group of people, to discover hidden patterns in trajectory data. Typically, the positions of moving objects are registered by GPS devices, and most of the time, the...

We study the double-cross matrix descriptions of polylines in the two-dimensional plane. The double-cross matrix is a qualitative description of polylines in which exact, quantitative information is given up in favour of directional information. First, we give an algebraic characterization of the double-cross matrix of a polyline and derive some pr...

Geographic Information Systems (GIS) have been extensively used in various application domains, ranging from economical, ecological and demographic analysis, to city and route planning. Nowadays, organizations need sophisticated GIS-based Decision Support System (DSS) to analyze their data with respect to geographic information, represented not onl...

Geographic Information Systems (GIS) have been extensively used in various application domains, ranging from economical, ecological and demographic analysis, to city and route planning. Nowadays, organizations need sophisticated GIS-based Decision Support System (DSS) to analyze their data with respect to geographic information, represented not onl...

Geographic Information Systems (GIS) have been extensively used in various application domains, ranging from economical, ecological and demographic analysis, to city and route planning. Nowadays, organizations need sophisticated GIS-based Decision Support System (DSS) to analyze their data with respect to geographic information, represented not onl...

Geographic Information Systems (GIS) have been extensively used in various application domains, ranging from economical, ecological and demographic analysis, to city and route planning. Nowadays, organizations need sophisticated GIS-based Decision Support System (DSS) to analyze their data with respect to geographic information, represented not onl...

A common problem in moving object databasesMOD) is the reconstruction of a trajectory from a trajectory sample �i.e., a finite sequence of time-space points). A typical solu- tion to this problem is linear interpolation. A more realistic model is based on the notion of uncertainty modelled by space-time prisms, which capture the positions where the...

Geographic Information Systems (GIS) have been extensively used in various application domains, ranging from economical, ecological and demographic analysis, to city and route planning. Nowadays, organizations need sophisticated GIS-based Decision Support System (DSS) to analyze their data with respect to geographic information, represented not onl...

A key issue in clustering data, regardless the algorithm used, is the definition of a distance function. In the case of trajectory data, different distance functions have been proposed, with different degrees of complexity. All these measures assume that trajectories are error-free, which is essentially not true. Uncertainty is present in trajector...

One of the formalisms to qualitatively describe polylines in the plane are double-cross matrices. In a double-cross matrix the relative position of any two line segments in a polyline is described with respect to a double cross based on their start points. Two polylines are called DC-similar if their double-cross matrices are identical. Although do...

This paper presents some approaches for geo-spatial analysis of movement behavior of visitors of recreational areas. The approaches are bases on the use of moving object databases containing Temporary Annotated Sequences (TAS). The TAS result from the use of GPS or mobile phones for tracking visitors. Two examples are presented for a case study...

We consider privacy preserving decision tree induction via ID3 in the case where the training data is horizontally or vertically distributed. Furthermore, we consider the same problem in the case where the data is both horizontally and vertically distributed, a situation we refer to as grid partitioned data. We give an algorithm for privacy preserv...

nformation and communication technologies (ICTs) touch many aspects of our lives. The integration of ICTs is enhanced by the advent of mobile, wireless, and ubiquitous technologies. ICTs are increasingly embedded in common services, such as mobile and wireless communication, Internet browsing, credit card e-transactions, and electronic health recor...

Due to inexpensive modern sensing technologies and extensive use of wireless communication, location information about moving objects is increasing rapidly. Some positioning technologies are based on GPS-equipped devices, while others utilize the infrastructure of the underlying communication network. This opens new opportunities for offering, moni...

In frequent geographic pattern mining a large amount of patterns can be non-novel and non-interesting. This problem has been addressed recently, and background knowledge is used to reduce well known geographic patterns. However, a large amount of meaningless patterns which is independent of domain knowledge is still extracted from geographic data....

The constant increase of moving object data imposes the need for modeling, processing, and mining tra- jectories, in order to nd and understand the pat- terns behind these data. Existing works have mainly focused on the geometric properties of trajectories, while the semantics and the background geographic information has rarely been addressed. We...

The collection of moving object data is becoming more and more common, and therefore there is an increasing need for the ecient analysis and knowledge extraction of these data in dierent application domains. Trajectory data are normally available as sample points, and do not carry se- mantic information, which is of fundamental importance for the c...

We present an algorithm for polyline (and polygon) simi- larity testing that is based on the double-cross formalism. To determine the degree of similarity between two polylines, the algorithm first computes their generalized polygons, that consist of almost equally long line segments and that approx- imate the length of the given polylines within a...