Advance in Moving Object Data Modeling under Geographic Network Environment

In recent years,along with the rapid development of location technologies such as GPS,RFID and wireless sensor networks as well as the widespread use of location-aware devices such as mobile phones and GPS receivers,large amounts of trajectories of moving objects can be easily acquired.By using moving objects databases,massive trajectories of moving objects can be manipulated and handled for various applications,which makes the study of moving objects databases more and more important.Among the most recent researches,the study space where moving objects travel can be mainly divided into two types,the Euclidean space and the geographic road networks.In Euclidean space,moving objects can move freely.However,under geographic network environment,moving objects are limited to geographic networks and must follow the road regulation.For the latter research branch is much more practical than the former one,this paper concerns the latter branch and focuses on modeling moving objects in geographic networks,which is the foundation of the study of moving objects databases.It has been a hot research topic in the field of moving objects database management and also provides key technology for many other areas such as transportation,location-based services,urban mobility and social computing.Although it is of great theoretical significance and application value,modeling moving object in geographic networks challenges the research community a lot due to network constraints.In this paper,firstly,most existent geographic network-constrained moving object data models over recent decades has been systematically reviewed and classified.The related literatures show that most geographic network-constrained models can be divided into four categories including edge-based network-constrained model,route-based network-constrained model,partition-based network-constrained model and spatial-temporal network-constrained model.Then model characteristics,advantages as well as limitations have been elaborately analyzed,based on which,finally some crucial points on modeling moving objects in geographic networks has been proposed and discussed.