Ismail Rakip Karas, "Evaluating Topological Relationships of the
Objects in 3D GIS and Network Analysis", PhD Thesis, 2007

(A 3DGIS Prototype Development for Network Analyses: Automatic Data
Extraction/Generation, Network Analyses, Simulation, and Navigation)

ABSTRACT

Keywords: Geographic information system (GIS), 3D GIS, automatic feature extraction,
network analysis, topology, simulation, navigation

In this study, it is aimed that to design a conceptual model and develop a 3D GIS application
for indoors which can be performed efficient network analysis. A functional and analysis
based GIS prototype was implemented based on modeling fundamentals and mathematical
infrastructure of 3D network analysis applications. The system consists of four components;
Automatic Data Generation, Network Analysis, Simulation, and Navigation.

A new method, MUSCLE (Multidirectional Scanning for Line Extraction) Model was
developed for Automatic Data Generation. By using this method, it is possible to efficiently
and automatically generate 3D Building and Network Models based on the floor plans of the
building. Therefore, the method is basically an image processing method and can be used for
automatic vectorization of raster images in general.

Network Analysis component has two functions; analysis and visualization. By using analysis
function, the users can select two entities in the building and optimum path between them is
calculated. By using visualization function, it is possible to view and navigate the 3D Models
and optimum path on the screen. In this application, it was indicated that the 3D network
analysis -which is the one of the most important analysis for indoors- can be performed
efficiently.

Simulation component was developed for modeling the movements of a person in the
building. In this application, navigation of the person is simulated as audible and visual.
In the navigation component, by using a user interactive positioning method, it was indicated
that a person can be reached his target without any problem. The areas such as evacuation and
address finding, etc. are the subjects of this kind of applications.
The thesis consists of four sections.

In the first section, the 3D GIS concept is explained and the difficulties in realizing 3D GIS or
3D geo-spatial systems are evaluated. The problem and the aim of thesis are defined. Then,
the scope is revealed and subjects of the thesis such as emergency services, transportation,
security, visitor guiding, service organization etc. are detailed. The overview and
methodology are also the part of the first section.

In the second section, the fundamentals of the 3D Network Analysis are investigated. Types
of the network analysis and topology concept are explained. Mathematical infrastructure of
the network analysis, Graph Theory, is described on a vast scale. Shortest path algorithms are
presented using detailed examples.

In the third section, developed system is introduced. Conceptual and logical design processes
explained. Mathematical and algorithmic fundamentals of the system are described in detail.
The fourth section includes the results and suggestions.