Sisi Zlatanova

The Balance Between Geometry and Topology

The architecture of Geographic Information Systems (GISs) is changing: more and more systems are based on the integrated architecture, i.e. storing geometric data in the Data Base Management System (DBMS) together with administrative data. The first step in building a Geo-DBMS is by having data types and operators for simple features (i.e. geometric primitives): point, line and polygon. This has reached a level of standardisation and is now implemented in several commercial DBMSs. The next step is to have support for the topologically structured features in the DBMS, i.e. complex features. The DBMS can then check and guarantee consistency. In addition, complex operations can be executed within the DBMS. Despite the fact that topologically structured models are well known and that it is not difficult to store the topological references, it still remains an unresolved issue as to how to effectively implement these models within a relational DBMS. In this paper, we describe the design and implementation of a topologically structured management at the DBMS level. Our focus is to translate topological structures into geometric primitives. It is then possible to define a DBMS view on a topological primitive, which makes this appear as a geometric primitive. This process supports the best of both worlds: on the one hand there are advantages of the topological structure (no redundancy) and on the other hand the ease of explicit geometric primitives in querying, analysis and presentation is available.

Evacuation Route Calculation of Inner Buildings

Disastrous accidents (fire, chemical releases, earthquake, terrorist attacks, etc) in large public and residential buildings (discotheques, cafes, trade and industrial buildings) usually result in tragic consequences for people and environments. Such accidents have clearly showed that need for reliable systems supporting rescue operations is urgently appealing. Amongst all, giving appropriate information to the ordinary people in/around the affected area considering the disaster developments (available exists, assessable corridors, etc.) and the human factors (age, gender, disability) are of critical importance for the success of the rescue operation.

Review: 3D geo-database research: Retrospective and future directions

3D geo-database research is a promising field to support challenging applications such as 3D urban planning, environmental monitoring, infrastructure management, and early warning or disaster management and response. In these fields, interdisciplinary research in GIScience and related fields is needed to support the modelling, analysis, management, and integration of large geo-referenced data sets, which describe human activities and geophysical phenomena. Geo-databases may serve as platforms to integrate 2D maps, 3D geo-scientific models, and other geo-referenced data. However, current geo-databases do not provide sufficient 3D data modelling and data handling techniques. New 3D geo-databases are needed to handle surface and volume models. This article first presents a 25-year retrospective of geo-database research. Data modelling, standards, and indexing of geo-data are discussed in detail. New directions for the development of 3D geo-databases to open new fields for interdisciplinary research are addressed. Two scenarios in the fields of early warning and emergency response demonstrate the combined management of human and geophysical phenomena. The article concludes with a critical outlook on open research problems.

Towards Defining a Framework for Automatic Generation of Buildings in CityGML Using Building Information Models

Increased demand for tools that allow merging of Building Information Models with GIS models is observed in the last several years. Professionals from both domains are looking for solutions to seamlessly integrate such models for various purposes such as, building and construction analysis, urban planning, tourism, cadastre, homeland security, etc. Researchers suggested that the best approach for such integration is harmonised semantics, which will allow formal mappings between the design (BIM) and real world (GIS) models. Although many geometric models have been developed in both domains, the number of semantic models is relatively few. Two most prominent semantic models in the design and real worlds are currently IFC and CityGML. Several studies demonstrate the transfer of information from IFC models into the CityGML but the literature is lacking a formal and descriptive framework for automatic generation of buildings in CityGML using the IFC models. This paper presents preliminary ideas for defining a semantic mapping, which will allow automatic transformations between the two models.

A BIM-Oriented Model for supporting indoor navigation requirements

Abstract Existing indoor navigation approaches such as navigation based on 2D geometries and pre-defined routing remain insufficient for many applications such as emergency response, delivery, utility maintenance and facility management. The insufficiencies caused by existing navigation approaches can be overcome by making use of the advanced semantic and geometric information included in intelligent building models. A key example of such models is Building Information Models (BIMs) which contain detailed geometric and semantic information about buildings. In fact, the BIMs’ structure is very complex for facilitating navigation. This paper presents a new BIM Oriented Modeling methodology resulting in the definition of a new BIM based model (BO-IDM) dedicated for facilitating indoor navigation. The paper later describes the transformation of information from a standard BIM (IFC) into the new model (BO-IDM). The innovation aspects of BO-IDM can be summarized as follows: (i) it provides highly detailed semantic information for indoor navigation and (ii) it represents the non-geo-referenced structure and complex geometries of BIMs with ISO 19107 compliant representations. Therefore this model is well suited for indoor navigation.

Advances in 3D Geoinformation Systems

This unique book focuses on comparing several types of 3D models. Due to the rapid developments in sensor techniques a vast amount of 3D data is available. Effective algorithms for (semi) automatic object reconstruction are required. Integration of existing 2D objects with height data is a non-trivial process and needs further research. The resulting 3D models can be maintained in several types of 3D models: TEN (Tetrahedral Network), Constructive Solid Geometry (CSG) models, Regular Polytopes, TIN Boundary representation and 3D volume quad edge structure, layered/topology models, voxel based models, 3D models used in urban planning/polyhedrons, and n-dimensional models including time. 3D analysis and 3D simulation techniques explore and extend the possibilities in spatial applications.

Ontologies for Disaster Management Response

Increasing numbers of natural disasters and man-made disasters, such as earthquakes, tsunamis, floods, air crashes, etc., have posed a challenge to the public and demonstrated the importance of disaster management. The success of disaster management, amongst all, largely depends on finding and successfully integrating related information to make decisions during the response phase. This information ranges from existing data to operational data. Most of this information is geographically related and therefore when discussing integration of information for disaster management response, we often refer to the integration of geo-information. Current efforts to integrate geo-information have been restricted to keyword-basedmatching Spatial Information Infrastructure (SII, may also known as Spatial Data Infrastructure). However, the semantic interoperability challenge is still underestimated. One possible way to deal with the problem is the use of ontology to reveal the implicit and hidden knowledge. This paper presents an approach for ontology development and ontology architecture, which can be used for emergency response.

Initial Investigations for Modeling Interior Utilities Within 3D Geo Context: Transforming IFC-Interior Utility to CityGML/UtilityNetworkADE

3D City models have so far neglected utility networks in built environments, both interior and exterior. Many urban applications, e.g. emergency response or maintenance operations, are looking for such an integration of interior and exterior utility. Interior utility is usually created and maintained using Building Information Model (BIM) systems, while exterior utility is stored, managed and analyzed using GIS. Researchers have suggested that the best approach for BIM/GIS integration is harmonized semantics, which allow formal mapping between the BIM and real world GIS. This paper provides preliminary ideas and directions for how to acquire information from BIM/Industry Foundation Class (IFC) and map it to CityGML utility network Application Domain Extension (ADE). The investigation points out that, in most cases, there is a direct one-to-one mapping between IFC schema and UtilityNetworkADE schema, and only in one case there is one-to-many mapping; related to logical connectivity since there is no exact concept to represent the case in UtilityNetworkADE. Many examples are shown of partial IFC files and their possible translation in order to be represented in UtilityNetworkADE classes.

Establishing a national standard for 3D topographic data compliant to CityGML

This article describes a research project that realised a national standard for 3D geo-information. The standard was developed as part of a pilot in which more than 65 private, public and scientific organisations collaborated to analyse and push 3D developments in the Netherlands (run between March 2010 and June 2011). The 3D standard was established through several steps. First, a comparison between the existing 3D computer-aided design and GIS standards was carried out that selected the Open Geospatial Consortium (OGC) standard CityGML as the optimal 3D standard to align to. Second, the equivalent concepts in CityGML and the existing national standard for large-scale topography (Information Model Geography [IMGeo]) were identified. Third, IMGeo was extended to 3D following the principles of CityGML Application Domain Extensions. The model was tested by applying it to real data. Based on the experiences of this pilot, this article proposes a framework of guidelines and principles for extending CityGML for national purposes, deduced from the modelling experiences. This is a unique contribution since experiences on extending CityGML are new and not well described in the OGC CityGML specifications. Finally, this article presents the change requests (CRs) which have been submitted to OGC to make the CityGML standard more suited for integration with existing 2D topographic information models. The CRs were formulated based on experiences from developing this nationwide 3D standard.

Indoor Pedestrian Navigation Using Foot-Mounted IMU and Portable Ultrasound Range Sensors

Many solutions have been proposed for indoor pedestrian navigation. Some rely on pre-installed sensor networks, which offer good accuracy but are limited to areas that have been prepared for that purpose, thus requiring an expensive and possibly time-consuming process. Such methods are therefore inappropriate for navigation in emergency situations since the power supply may be disturbed. Other types of solutions track the user without requiring a prepared environment. However, they may have low accuracy. Offline tracking has been proposed to increase accuracy, however this prevents users from knowing their position in real time. This paper describes a real time indoor navigation system that does not require prepared building environments and provides tracking accuracy superior to previously described tracking methods. The system uses a combination of four techniques: foot-mounted IMU (Inertial Motion Unit), ultrasonic ranging, particle filtering and model-based navigation. The very purpose of the project is to combine these four well-known techniques in a novel way to provide better indoor tracking results for pedestrians.