Now showing 1 - 4 of 4
  • Publication
    Modeling micro-movement variability in mobility studies
    During the past years the interest in the exploitation of mobility information has increased significantly. Along with these interests, new demands on mobility data sets have been posed. One particular demand is the evaluation of movement data on a high level of spatial detail. The high dimensionality of geographic space, however, makes this requirement hard to fulfill. Even large mobility studies cannot guarantee to comprise all movement variation on a high level of detail. In this paper we present an approach to increase the variability of movement data on microscopic scale in order to achieve a better representation of population movement. Our approach consists of two steps. First, we perform a spatial aggregation of trajectory data in order to counteract sparseness and to preserve movement on macroscopic scale. Second, we disaggregate the data in geographic space based on traffic distribution knowledge using repeated simulation. Our approach is applied in a real-world business application for the Ger-man outdoor advertising industry to measure the performance of poster sites.
  • Publication
    Spatial data mining in practice
    Almost any data can be referenced in geographic space. Such data permit advanced analyses that utilize the position and relationships of objects in space as well as geographic background information. Even though spatial data mining is still a young research discipline, in the past years research advances have shown that the particular challenges of spatial data can be mastered and that the technology is ready for practical application when spatial aspects are treated as an integrated part of data mining and model building. In this chapter in particular, we give a detailed description of several customer projects that we have carried out and which all involve customized data mining solutions for business relevant tasks. The applications range from customer segmentation to the prediction of traffic frequencies and the analysis of GPS trajectories. They have been selected to demonstrate key challenges, to provide advanced solutions and to arouse further research questions.
  • Publication
    Sample bias due to missing data in mobility surveys
    A growing number of companies use mobility information in their day-to-day business. One requirement thereby is that inference about population-wide mobility patterns can be made. Therefore, it is not only important to find mobility patterns in a given data sample but also to assert their validity for the total population. This aspect of analysis has been largely neglected in mobility data mining research, which limits the applicability of the whole algorithmic field. In this paper we will analyze one aspect of sample bias due to incomplete mobility data. We will provide a systematic approach to detect dependencies between mobility behavior, socio-demography and missing data. Further, we apply the approach to a large GPS mobility survey in Switzerland and show that our concerns are justified and require attention in future research. We hope that our paper will raise the awareness that representativity of mobile behavior cannot be taken for granted in mobility surveys du e to missing data and is a research direction of utmost importance.
  • Publication
    A general pedestrian movement model for the evaluation of mixed indoor-outdoor poster campaigns
    Over the last few years new measurement technology has revolutionized the performance measurement in outdoor advertising. A handful of pioneer countries trace personal mobility now via GPS devices, which allows for precise performance results of arbitrarily positioned outdoor poster campaigns. However, GPS technology has the drawback that it cannot be applied indoors due to signal loss. In Switzerland and Germany many valuable posters are situated in public buildings such as train stations or shopping malls and their evaluation is of high interest. In this paper we therefore present a new approach for the evaluation of mixed indoor-outdoor campaigns. Our approach consists of a general pedestrian movement model in restricted spaces which can be integrated into standard trajectory evaluation. Our approach has been implemented for 27 major train stations in Switzerland.