Jung-Rae Hwang

Spatio-temporal similarity analysis between trajectories on road networks

In order to analyze the behavior of moving objects, a measure for determining the similarity of trajectories needs to be defined. Although research has been conducted that retrieved similar trajectories of moving objects in Euclidean space, very little research has been conducted on moving objects in the space defined by road networks. In terms of real applications, most moving objects are located in road network space rather than in Euclidean space. In this paper, we investigate the properties of similar trajectories in road network space. And we propose a method to retrieve similar trajectories based on this observation and similarity measure between trajectories on road network space. Experimental results show that this method provides not only a practical method for searching for similar trajectories but also a clustering method for trajectories.

Trajectory Analysis for Soccer Players

In order to make good strategies, soccer coaches analyze the archives of matches, which can be effectively considered as a set of trajectories. We can extract several useful information by analyzing the trajectories of moving objects, which consist of 22 players and a ball. Since each moving object interacts with others and produces a trajectory, its trajectory has a certain number of relationships with others, which are a basic type of information to make soccer strategies. In this paper, we propose a model to quantitatively express the performance of soccer players. This model is based on the relationships between trajectories of 22 players and a ball and allows to evaluate the performance of several players in quantitative way

Searching for similar trajectories on road networks using spatio-temporal similarity

In order to search similar moving object trajectories, the previously used methods focused on Euclidean distance and considered only spatial similarity. Euclidean distance is not appropriate for road network space, where the distance is limited to the space adjacent to the roads. In this paper, we consider the properties of moving objects in road network space and define temporal similarity as well as spatio-temporal similarity between trajectories based on POI (Points of Interest) and TOI (Times of Interest) on road networks. Based on these definitions, we propose methods for searching for similar trajectories in road network space. Experimental results show the accuracy of our methods and the average search time in query processing.

Query transformation method by delaunay triangulation for multi-source distributed spatial database systems

One of the difficulties in building a distributed GIS comes from the heterogeneity of spatial databases. In particular, positional mismatches between spatial databases arise due to several reasons, such as different scales, or different ground control points. They result in unreliable outputs of query processing. One simple solution is to correct positional data in spatial databases at each site, according to the most accurate one. This solution is however not practical in most of the cases where the autonomy of each database should be respected. In this paper, we propose a spatial query processing method without correcting positional data in each spatial database. Instead of correcting positional data, we dynamically transform a given query region or position onto each space where spatial objects of each site are located. Our method is based on an elastic transformation method by delaunay triangulation.

Effective Determination of Optimal Regularization Parameter in Rational Polynomial Coefficients Derivation

Recently, massive archives of ground information are provided by imagery from new sensors. To establish the functional relationship between image and ground space, sensor models are required. The rational functional model (RFM), which is used as an alternative to rigorous sensor model, becomes attractive due to its generality and simplicity. To get a rational polynomial coefficients (RPC) in RFM, we encounter the problem for obtaining a stable solution, because design matrix for solutions usually ill-conditioned in the experiments. To solve such an unstable problem, regularization techniques are generally used. In this paper, we describe the determination of optimal regularization parameter in the regularization technique during RPC derivation. A brief mathematical background of RFM is presented, followed by numerical approaches for automatic determination of optimal regularization parameter with the Euler Method. Experiments are carried out; assuming tilted aerial image is taken with known rigorous sensor model.

Implementation of prototype for interoperability between BIM and GIS: Demonstration paper

Recently, researches for correlation and integration between BIM (Building Information Modeling) and GIS (Geographic Information System) have been attempted at home and abroad. However, it is difficult to connect and integrate the two data models because characteristics and domains between BIM and GIS data models are very different. In this research, we implemented a prototype to secure the interoperability between BIM and GIS by efficient systemic approach.

Development of an editor and a viewer for IndoorGML

With the growth of building complexity, spatial information services in indoor space is now increasing as important application area of GIS as outdoor space. Based upon this, many studies have been started to research representation methods for 3-D indoor space and connection method between indoor and outdoor. In this research, we developed the editor and viewer based on IndoorGML which defined with international standardization process.

A study on the correlation analysis for connection between IFC and CityGML

Recently, various researches have been attempted to integrate between the building information handling BIM and the spatial information handling GIS. Particularly, some of the researches were progressed to convert the data model between the BIM standard model IFC and the GIS standard model CityGML. However, because characteristics and domains of between the two data models are very different, it is hard to utilize the previous research results yet. Accordingly, in order to obtain the interoperability between BIM and GIS, the characteristics and correlations between IFC and CityGML objects of each LOD were analyzed in this research. Thereupon, with these analysis results as the background, from view point of building information, a correlation mapping was performed between objects of IFC and CityGML. In the future, there are plans to continue this research in order to derive a standard model for the data conversion between the IFC and CityGML.