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296

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Introduction

**Skills and Expertise**

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May 1989 - present

## Publications

Publications (296)

This is a report on a workshop entitled "Languages of Spatial Relations", held in Goleta and Montecito, California, January15-19, 1989. The organizers wish to thank the management and staff of Casa di Maria (the conference site) for providing anexcellent environment for the meeting, and Sandy Glendenning, Phil Parent, and others at the NCGIA head o...

Topological relations are the predominant backbone of qualitative spatial reasoning, focusing to date mostly on objects that are embedded in ℝ 2. With the advent of ball-shaped screen technologies and the growing importance of globally situated data, the digital sphere, known as í µíµ 2 , becomes a viable embedding. While topological relations hav...

Artificial intelligence and satellites have brought spatial-image interpretation to the forefront. Over the past two decades, the literature has provided three distinct methods for identifying and classifying the boundary of raster objects: the digital Jordan curve, the hyper-raster, and a marginal approach. While each approach has its own merits a...

Andrew Frank, who retired in September 2016 from the chair of geoinformation position at the Vienna University of Technology that he had held for a quarter century, has had an extraordinary influence on our field. His curiosity and wide spanning intellectual interests enriched the field’s foundations and propelled it in many ways. To name just one...

A complete qualitative scene description should be such that it captures the essential details of a configuration so that a topologically correct depiction can be recreated. This paper models a spatial scene through sequences of point partitions, that is, how embedding space and objects are distributed around the intersections of the boundaries of...

This paper summarizes the discussions related to the panel “Contributions of GIScientists (or GIScience) over the past Twenty Years” at the 2015 Vespucci Institute. Reflections about the past not only provide an account of what occurred, but also may serve as a basis for comparison when in the future somehow related scenarios arise. Such histories...

Excel based Implementation of Image Analysis Technique for Dube, Barrett, Egenhofer - 2015

Spatial regions are a fundamental abstraction of geographic phenomena. While simple regions—disk-like and simply connected—prevail, in partitions complex configurations with holes and/or separations occur often as well. Swiss cantons are one highlighting example of these, bringing in addition variations of holes and separations with point contacts....

This paper considers the nineteen planar discrete topological relations that apply to regions bounded by a digital Jordan curve. Rather than modeling the topological relations with purely topological means, metrics are developed that determine the topological relations. Two sets of five such metrics are found to be minimal and sufficient to uniquel...

The field of spatial reasoning has provided a litany of formal models and reasoning systems aimed at providing users with information about spatial tasks and concepts, ranging from point-to-point distance measurements coming from sensors all the way to topological information coming from the interaction of multiple sensor readings. In this short pa...

Surrounds is a topological relation that can exist between two regions or between collections of regions in ℝ2. This paper provides an algebraic construction for surrounds within a partition and provides a complementary graph-theoretic approach for the detection of the surrounds conditions created by the operations within the algebra. These two app...

This paper defines the Field data type for big spatial data. Most big spatial data sets provide information about properties of real-ity in continuous way, which leads to their representation as fields. We develop a generic data type for fields that can represent di↵erent types of spatiotemporal data, such as trajectories, time series, remote sensi...

The typical phenomena in geographic space are 2-dimensional or 3-dimensional in nature, yet people often conceptualize some of them as 1-dimensional entities embedded in a 2-dimensional space—rivers have widths and depths, and extent across the surface of the Earth, but for some tasks they are thought of as linear objects; likewise, roads as travel...

Forerunner to Topological Augmentation papers to come

Spatial scenes are abstractions of some geographic reality, focusing on the spatial objects identified and their spatial relations. Such qualitative models of space enable spatial querying, computational comparisons for similarity, and the generation of verbal descriptions. A specific strength of spatial scenes is that they offer a focus on particu...

Klippel has recently identified topological relativity as an important question for geographic information theory. One way of looking at theimportance of topology in spatial reasoning and in spatial theory is to assess commonplace terms from natural language relative to conceptual neighborhood graphs, the alignment structures of choice for topologi...

This paper develops a method to determine consistenly the integration of spatial integrity specifications, particularly for the case when two constraints, c1 and c2, are applied between three classes A, B, C (i.e., A c1 B and B c2 C), as such scenarios give rise to an implied consistency constraint c3 that holds between A and C. To determine c3, th...

Two formalisms for binary topological spatial relations are compared for their expressive power. The 4-intersection considers the two objects' interiors and boundaries and analyzes the intersections of these four object parts for their content (i.e., emptiness and non-emptiness). The 9-intersection adds to the 4-intersection the intersections with...

This paper revisits conceptual neighborhood graphs for the topological relations between two regions, in order to bridge from the A-B-C neighborhoods defined for interval relations in R1 to region relations in R2 and on the sphere S2. A categorization of deformation types - built from same and different positions, orientations, sizes, and shapes -...

Qualitative spatial relations are symbol abstractions of geometric representations, which allow computational analyses independent of, but consistent with, graphical depictions. This paper compiles some of the most commonly used sets of qualitative spatial relations and their logical inference mechanisms. The abstract representation of the relation...

A current trend in the development of spatial-relation ontologies is to capture more and more details about the geometries of the spatial objects that are related, primarily by topological relations. In an effort to bridge between often disparate approaches, a reference system for topological relations between compound spatial objects is introduced...

Naive Geography's premise "Topology matters, metric refines" calls for metric properties that provide opportunities for finergrained distinctions than the purely qualitative topological relations. This paper defines a comprehensive set of eleven metric refinements that apply to the eight coarse topological relations between two regions that the 9-i...

Relation models have treated multi-holed regions relations either the same as hole-free regions relations, loosing this way
the peculiarities of the holed topology, or with methods dependent on the number of holes. This paper discusses a model of
relations between a hole-free and a multi-holed region that departs from past approaches by using the f...

Within the Geospatial Semantic Web, selecting a different ontology for a spatial data set will enable that data's analysis in a different context. Analyses of multiple data sets, each based on a different ontology, require appropriate bridges across the ontologies. This paper focuses on establishing such a bridge across two topological-relation ont...

Behavioural monitoring often concerns the interpretation of the motion of an agent with respect to an area of interest. Geometrically, the trajectory of the agent is represented by a directed line segment (DLine) around/over a region. Topological relations between a DLine and a region concern how the DLine intersect with the region and, therefore,...

People often sketch diagrams to facilitate their communication. If computers understood such diagrams, people could interact with information systems more intuitively using similar multimodal dialogs that include sketched diagrams. It remains a challenging problem, however, to make computers interpret arrow symbols, which are a frequent and versati...

Assessing spatial scenes for similarity is difficult from a cognitive and computational perspective. Solutions to spatial-scene similarity assessments are sensible only if corresponding elements in the compared scenes are identified correctly. This matching process becomes increasingly complex and error-prone for large spatial scenes as it is quest...

The discontinuities in boundaries and exteriors that regions with holes expose offer opportunities for inferences that are
impossible for regions without holes. A systematic study of the binary relations between single-holed regions shows not only
an increase in the number of feasible relations (from eight between two regions without holes to 152 f...

Computational similarity assessments over spatial objects are typically decomposed into similarity comparisons of geometric and non-geometric attribute values. Psychological findings have suggested that different types of aggregation functions—for the conversions from the attributes’ similarity values to the objects’ similarity values—should be use...

An automated extraction of regions from sketches can be of great value for multi-modal user interfaces and for interpreting spatial data. This paper develops the Perceptual Sketch Interpretation algorithm, which employs the theory of topological relations from spatial reasoning as well as good continuity from gestalt theory in order to model people...

Conceptual neighborhood graphs form the foundation for qualitative spatial-relation reasoning as they capture the relations’
similarity. This paper derives the graphs for the thirty-three topological relations between two crisp, undirected lines and
for the seventy-seven topological relations between two lines with uncertain boundaries. The analysi...

Cavities in spatial phenomena require geometric representations of regions with holes. Existing models for reasoning over
topological relations either exclude such specialized regions (9-intersection) or treat them indistinguishably from regions
without holes (RCC-8). This paper highlights that inferences over a region with a hole need to be made s...

Forty-four relations are found between an interval and an interval with a gap ( r<sub>II</sub> <sub>g</sub>), capturing semantics that are distinct from those of the sets of constituting intervals and at a higher semantic level than pure point-based models. The relations' conceptual neighborhood graph evolves as a refinement of the graph of Allen's...

The advent of wireless technology, such as cellphones, PDAs, tablet PCs, and sub-notebooks, allows transferring portions of traditional, desktop-based GIS technology to mobile environments. This paper introduces Geo-Mobile Query-by-Sketch, a sketch-based spatial querying system for mobile GIS environments that combines,techniques for spatial queryi...

Many real and artificial entities in geographic space, such as transportation networks and trajectories of movement, are typically modelled as lines in geographic information systems. In a similar fashion, people also perceive such objects as lines and communicate about them accordingly as evidence from research on sketching habits suggests. To fac...

This paper develops a formal model of topological relations between a directed line segment (DLine) and a region in a two-dimensional space. Such model forms a foundation for characterizing movement patterns of an agent with respect to a region. The DLine-region relations are captured by the 9- intersection for line-region relations with further di...

During the last two decades the topic of constraint databases has evolved into a mature area of computer science with sound mathematical foundations and with a profound theoretical understanding of the expressive power of a variety of query languages. Constraint databases are especially suited for applications in which possibly infinite sets of con...

From 20.05. to 25.05., the Dagstuhl Seminar 07212 ``Constraint Databases, Geometric Elimination and Geographic Information Systems'' was held
in the International Conference and Research Center (IBFI),
Schloss Dagstuhl.
During the seminar, several participants presented their current
research, and ongoing work and open problems were discussed. Abst...

The assessment of semantic similarity among objects is a basic requirement for semantic interoperability. This paper presents
an innovative approach to semantic similarity assessment by combining the advantages of two different strategies: feature-matching
process and semantic distance calculation. The model involves a knowledge base of spatial con...

Directed line segments are fundamental geometric elements used to model through their spatial relations such concepts as divergence,
confluence, and interference. A new model is developed that captures spatial relations between pairs of directed line segments
through the intersections of the segments’ heads, bodies, and tails. This head-body-tail i...

This paper presents two models for determining the uncertainty in the topological relations between two lines. One model considers the uncertainty associated with the position of the line, while the other model captures the uncertainty associated with the position of the nodes. The first case considers a region of uncertainty surrounding the entire...

Illustrating a dynamic process with an arrow-containing diagram is a widespread convention in people's daily communications. In order to build a basis for capturing the structure and semantics of such diagrams, this paper formalizes the topological relations between two arrow symbols and discusses the influence of these topological relations on the...

Current geographic information systems (GISs) have been designed for querying and maintaining static databases representing static phenomena and give little support to those users who wish to represent dynamic information or incorporate temporality into their studies. In order to integrate phenomena that change over space and time in GISs, a better...

This paper addresses changes in topological relations as they occur when splitting a region into two. It derives systematically
what qualitative inferences can be made about binary topological relations when one region is cut into two pieces. The new
insights about the possible topological relations obtained after splitting regions form a foundatio...

Arrow symbols are an essential tool for visual communications. Although arrow symbols look familiar and intuitive, diagram readers have to interpret the semantic role of each arrow symbol in the diagram, since arrow symbols are versatile and often used multi-purposely without specification. This paper reveals that such interpretation requires backg...

Traditional GIS tools are well suited for desktop workstations, but need to be adapted in order to satisfy the requirements of mobility. We propose a concept for sketch-based spatial querying in mobile GIS environments. This concept combines newest techniques for spatial querying and mobile technologies. Such a combination is beneficial because it...

Arrows are major components of diagrams, where they are typically used to facilitate the communication of spatial and temporal knowledge. An automated interpretation of arrow diagrams would be highly desirable in pen-based interfaces. This paper develops a method for deducing possible interpretations of arrow diagrams, which is composed of a uni-di...

Different users of geospatial information have different requirements of that information. Matching information to users’ requirements demands an understanding of the ontological aspects of geospatial data. In this paper, we present an ontology-driven map generalization algorithm, called DMin, that can be tailored to particular users and users’ tas...

As location-based applications become part of our everyday life, ranging from traffic prediction systems to services over mobile phones providing us with information about our surroundings, the call for more semantics and accurate services is emerging. In this work, we analyze and register the data semantics of Location-based Services (LBS). Initia...

Arrows illustrate a large variety of semantics in diagrams. An automated interpretation of arrows would be highly desirable in pen-based interfaces. This paper formalizes the structural patterns of arrows, and identifies three structural properties that contribute to the interpretation of arrows: (1) the assignment of components to three slots, (2)...

For present purposes, the opposition between 1 and 2 is especially important. Ontology in the first sense can also be characterized as a conception of ontology as a theory of reality, by analogy with any other scientific theory, though specializing primarily in the preparation of taxonomies of the types of entities existing in a given domain (inclu...

A representation is a means to communicate geographic information, and is also a binary structure in a computer or electronic storage medium that corresponds with an object, measurement, or phenomenon in the world. The representation chosen for a geographic phenomenon has a profound impact on interpretation and analysis. The selection of informatio...

Spatial and temporal database systems, both in theory and in practice, have developed dramatically over the past two decades to the point where usable commercial systems, underpinned by a robust theoretical foundation, are now starting to appear. While much remains to be done, topics for research must be chosen carefully to avoid embarking on impra...

Within the geographic domain, an important class of problems relies on geometric abstractions in the form of lines where, for instance, transportation networks and trajectories of movements are typically perceived or modeled at such a generalized geometric level. To support querying and computational comparisons, oftentimes multi-resolution models...

Semantic similarity plays an important role in geographic information systems as it supports the identification of objects that are conceptually close, but not identical. Similarity assessments are particularly important for retrieval of geospatial data in such settings as digital libraries, heterogeneous databases, and the World Wide Web. Although...

Introduction Advances in sensor technology and deployment strategies are revolutionizing the way that geospatial information is collected and analyzed. For example, cameras and GPS sensors on-board static or mobile platforms have the ability to provide continuous streams of geospatially-rich information. Furthermore, with the advent of nano-technol...

This book constitutes the refereed proceedings of the Third International Conference on Geographic Information Science, GIScience 2004, held in Adelphi, MD, USA in October 2004.
The 25 revised full papers presented were carefully reviewed and selected from many submissions. Among the topics addressed are knowledge mapping, geo-self-organizing maps,...

Semantic similarity plays an important role in geographic information systems as it supports the identification of objects that are conceptually close, but not identical. Similarity assessments are particularly important for retrieval of geospatial data in such settings as digital libraries, heterogeneous databases, and the World Wide Web. Although...

In current dynamic data models for VR environments, the focus has been the graphical presentation of objects and an efficient running of animations. In such models the objects’ semantics are almost always assumed by the observer and derived from the context of the application. In this paper we introduce a model to represent the evolution of VR Obje...

To travel successfully in a dynamic space-time setting, wayfinders must project the impact of a changing environment onto future travel choices. When making decisions, however, people often fail to consider the impact of future changes. They instead overly rely on current system states. In addition, spatial information systems designed for wayfinde...

The scope of this paper is a qualitative description of terrain features that can be characterized using the silhouette of a terrain. The silhouette is a profile of a landform seen from a particular observer's perspective. We develop a terrain language as a formal framework to capture terrain features. The horizon of a terrain silhouette is represe...

This paper derives and compares two strategies for minimizing topological constraints in a query expressed by a visual example: (1) elimination of topological relations that are implied uniquely by composition and (2) restriction to topological relations that relate near-neighbor objects, as determined by a Delaunay triangulation. In both cases, th...

Traditional spatial querying assumes that a user specifies exactly the constraints of valid results, and that the result set contains only those items that fulfill exactly the query constraints. The nature of spatial data, however, makes it difficult for a user to always guess correctly the values stored, while exhaustive enumerations of acceptable...

This paper derives and compares two strategies for minimizing topological constraints in a query expressed by a visual example: (1) elimination of topological relations that are implied uniquely by composition and (2) restriction to topological relations that relate near-neighbor objects, as determined by a Delaunay triangulation. In both cases, th...

Semantic similarity measures play an important role in information retrieval and information integration. Traditional approaches to modeling semantic similarity compute the semantic distance between definitions within a single ontology. This single ontology is either a domain-independent ontology or the result of the integration of existing ontolog...

We use an example from information retrieval to explore Web-based semantics, which can be presented in different ways and carried by different bearers of the information retrieval process. We describe four presentations of semantics: natural language with minimal markup, simple metadata, basic data models, and logical semantics. Each presentation o...

We present a conceptualization of an animation data model for exploration of multi-dimensional environments. Specifically, we present the dynamic and temporal parts of a framework for exploratory analysis of animations in VR settings. The proposed model is tailored for both modelers and non-expert users to manipulate and analyze the output of a sim...

Semantic processing of spatial data is an emerging area of Geomatics that focuses on representation and use of knowledge to support (semi) automatic Geographic Information Systems (GIS). Due to the growing demand for both interactive an d automatic intelligent GIS, the field of semantic processing of spatial dat a has an exciting and promising futu...

Like people who casually assess similarity between spatial scenes in their routine activities, users of pictorial databases are often interested in retrieving scenes that are similar to a given scene, and ranking them according to degrees of their match. For example, a town architect would like to query a database for the towns that have a landscap...

that currently available methods for finding and using information on the web are often insufficient. In order to move the Web from a data repository to an information resource, a totally new way of organizing information is needed. The advent of the Semantic Web promises better retrieval methods by incorporating the data's semantics and exploiting...

This paper introduces a model to represent the evolution of VR objects over time. Based on this model a new classification of virtual reality objects is proposed and the semantics associated with each class of object are described. This paper also presents a rationale for modifying object semantics under manipulations by an observer of the object b...