Matt Duckham

Matt Duckham
RMIT University | RMIT · School of Science

PhD, University of Glasgow
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About

155
Publications
21,984
Reads
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4,251
Citations
Citations since 2017
21 Research Items
1461 Citations
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2017201820192020202120222023050100150200250
2017201820192020202120222023050100150200250

Publications

Publications (155)
Conference Paper
Full-text available
Although geospatial question answering systems have received increasing attention in recent years, existing prototype systems struggle to properly answer qualitative spatial questions. In this work, we propose a unique framework for answering qualitative spatial questions, which comprises three main components: a geoparser that takes the input ques...
Chapter
Indoor navigation systems help people to navigate through indoor environments. Conventional models of indoor navigation commonly assume that a navigator’s location can be precisely determined. However, the limitations of indoor positioning systems as well as personal privacy constraints mean it is not always possible to determine individual’s posit...
Article
Understanding urban areas of interest (AOIs) is essential in many real-life scenarios, and such AOIs can be computed based on the geographic points that satisfy user queries. In this article, we study the problem of efficient and effective visualization of user-defined urban AOIs in an interactive manner. In particular, we first define the problem...
Conference Paper
Full-text available
Designing a Geospatial Question Answering (GeoQA) system that takes a user’s GIS-related domain question, understands how to gather the required data, how to analyse it, and how to present the results in a suitable format is arguably among the most important “moonshots” in the GeoAI field. In this study, we focus specifically on answering geo-event...
Article
Full-text available
Computing trajectory similarity is a fundamental operation in movement analytics, required in search, clustering, and classification of trajectories, for example. Yet the range of different but interrelated trajectory similarity measures can be bewildering for researchers and practitioners alike. This paper describes a systematic comparison and met...
Article
Full-text available
This paper explores a class of qualitative-geometric relations between disjoint regions, embedded in the surface of a sphere or in the plane. These relations combine topological information about the configuration of the regions themselves as well as of the geometric Voronoi regions surrounding them. The method uses maptrees to construct a rigorous...
Article
Full-text available
Spatial information science has given rise to a set of concepts, tools, and techniques for understanding our geographic world. In turn, the technologies built on this body of knowledge embed certain ways of knowing." This vision paper traces the roots and impacts of those embeddings and explores how they can sometimes be inherently at odds with or...
Article
Indigenous knowledge of place is not well‐served by today's digital geospatial technologies, such as spatial data, maps, spatial databases, and GIS. This paper aims to identify and explore new connections between Indigenous knowledge of place and digital geospatial technologies. Our analysis is structured around three key gaps in past work: (a) the...
Article
Full-text available
The inherent complexity of environmental models is frequently a limiting factor in their usefulness and practical applicability. This paper aims to demonstrate how scientific workflows can increase the reproducibility of environmental models by better managing this complexity. Specifically, through the example of Solar Analyst solar radiation model...
Technical Report
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Concept Paper exploring how land and geospatial professionals can start to understand the impact of the Victorian treaty process and work to support this.
Article
This paper reports on a controlled experiment evaluating how different cartographic representations of risk affect participants’ performance on a complex spatial decision task: route planning. The specific experimental scenario used is oriented towards emergency route-planning during flood response. The experiment compared six common abstract and m...
Article
Full-text available
Reproducibility is widely regarded as crucial for scientific studies, yet there is still a lack of reproducibility in geospatial research. New sources of crowdsourced geoinformation provide new opportunities, but also complicate the reproducibility situation. Consequently, there is untapped potential in the domain of disaster response to reuse scie...
Article
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The proliferation of digital data and internet-based research technologies is transforming the research landscape, and researchers and research ethics communities are struggling to respond to the ethical issues being raised. This paper discusses the findings from a collaborative project that explored emerging ethical issues associated with the expa...
Article
This article concerns the definition and identification of qualitative spatial relationships for the full and partial enclosure of spatial regions. The article precisely defines three relationships between regions—“surrounds,” “engulfs,” and “envelops”—highlighting the correspondence to similar definitions in the literature. An efficient algorithm...
Article
This article concerns the opportunities for analysis of data about movement past spatial checkpoints. Checkpoint data are generated by an object’s movement past fixed sensors (‘checkpoints’) distributed throughout geographic space. Example sources of checkpoint data include road-toll gantries, social media check-ins, WiFi hotspots, access swipe car...
Conference Paper
Redundancy checking is an important task in AI subfields such as knowledge representation and constraint solving. This paper considers redundant topological constraints, defined in the region connection calculus RCC8. We say a constraint in a set C of RCC8 constraints is redundant if it is entailed by the rest of C. A prime subnetwork of C is a sub...
Article
Overviews of spatiotemporal data are acknowledged to play an important role in visualization in initiating and supporting geovisualization and exploratory data analysis (EDA). However, relatively little research has focused on the visual overviews themselves, and their potential impacts on EDA outcomes. In a user study, we evaluated the influence o...
Article
Full-text available
This paper examines the current state of three of the key areas of geospatial science in Australia: positioning; earth observation (EO); and spatial infrastructures. The paper discusses the limitations and challenges that will shape the development of these three areas of geospatial science over the next decade and then profiles what each may look...
Poster
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Objective This project will build a small demonstrator tool to show the capabilities and benefits of adopting open scientific workflow models for spatial analytics.
Conference Paper
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Movement data comes in various forms, including trajectory data and checkpoint data. While trajectories give detailed information about the movement of individual entities, checkpoint data in its simplest form does not give identities, just counts at checkpoints. However, checkpoint data is of increasing interest since it is readily available due t...
Article
Full-text available
Several algorithms have been proposed to generate a polygonal ‘footprint’ to characterize the shape of a set of points in the plane. One widely used type of footprint is the χ-shape. Based on the Delaunay triangulation (DT), χ-shapes guaranteed to be simple (Jordan) polygons. This paper presents for the first time an incremental χ-shape algorithm,...
Article
Full-text available
Many spatial analyses involve constructing possibly non-convex polygons, also called “footprints,” that characterize the shape of a set of points in the plane. In cases where the point set contains pronounced clusters and outliers, footprints consisting of disconnected shapes and excluding outliers are desirable. This paper develops and tests a new...
Article
Full-text available
Real-time information about the spatial extents of evolving natural disasters, such as wildfire or flood perimeters, can assist both emergency responders and the general public during an emergency. However, authoritative information sources can suffer from bottlenecks and delays, while user-generated social media data usually lacks the necessary st...
Article
Full-text available
Ordinary Kriging is widely used for geospatial interpolation and estimation. Due to the time complexity of solving the system of linear equations, ordinary Kriging for a large set of source points is computationally intensive. Conducting real-time Kriging interpolation over continuously varying spatiotemporal data streams can therefore be especiall...
Article
The paper investigates whether the methods chosen for representing uncertain geographic information aid or impair decision-making in the context of wildfire hazard. Through a series of three human subject experiments, utilizing 180 subjects and employing increasingly difficult tasks, this research evaluates the effect of five different visualizatio...
Research
Full-text available
Short communication on the SPATIAL 2015 conference, held at UCSB, December 9-11, 2015.
Article
This article describes research into the design and analysis of decentralized algorithms for computing convoy patterns (a density-based movement pattern amongst moving point objects, previously formalized and computed in a centralized manner). A series of decentralized algorithms are presented and discussed (naïve, tree-based, and further devolved...
Article
Full-text available
This paper develops a new mechanism to efficiently compute and compactly store qualitative spatial relations between spatial objects, focusing on topological and directional relations for large datasets of region objects. The central idea is to use minimum bounding rectangles (MBRs) to approximately represent region objects with arbitrary shape and...
Article
Full-text available
This research investigates the performance of graphical dot arrays designed to make discrimination of relative numerosity as effortless as possible at the same time as making absolute (quantitative) numerosity estimation as effortful as possible. Comparing regular, random, and hybrid (randomized regular) configurations of dots, the results indicate...
Conference Paper
This paper is concerned with the problem of detecting causality in spatiotemporal data. In contrast to most previous work on causality, we adopt a logical rather than a probabilistic approach. By defining the logical form of the desired causal rules, the algorithm developed in this paper searches for instances of rules of that form that explain as...
Article
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Over recent years considerable research effort has focused on developing decentralized algorithms for highly distributed computing environments, such as wireless geosensor networks. There are several putative advantages of decentralization, including scalability, energy efficiency, and operational latency. However, decentralized algorithms today ar...
Article
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This paper describes an efficient, decentralized algorithm to monitor qualitative spatial events in a dynamic scalar field. The events of interest involve changes to the critical points (i.e., peak, pits and passes) and edges of the surface network derived from the field. Four fundamental types of event (appearance, disappearance, movement and swit...
Conference Paper
Increasingly, various services are deployed and orchestrated in the cloud to form global, large-scale systems. The global distribution, high complexity, and physical separation pose new challenges into the quality assurance of such complex services. One major challenge is that they are intricately connected with the spatial and temporal characteris...
Article
Full-text available
This paper concerns the theoretical foundations of movement informatics. We discuss general frameworks in which models of spatial movement may be developed. In particular, the paper considers the object-field and Lagrangian-Eulerian dichotomies, and the SNAP/SPAN ontologies of the dynamic world, and classifies the variety of informatic structures a...
Article
This article concerns the identification of the expertise that GI scientists have in common. Rather than attempt to be exhaustive, the approach is to identify a minimal set of expert topics shared across GI science. In this article, a set of five expert topics is proposed for this purpose: structure, uncertainty, dynamism, language and cognition, a...
Conference Paper
Full-text available
Managing the data generated by emerging spatiotemporal data sources, such as geosensor networks, presents a growing challenge to traditional, offline GIS architectures. This paper explores the development of an end-to-end system for near real-time monitoring of environmental variables related to wildfire hazard, called RISER. The system is built up...
Article
Full-text available
Storing, querying, and analyzing trajectories is becoming increasingly important, as the availability and volumes of trajectory data increases. One important class of trajectory analysis is computing trajectory similarity. This paper introduces and compares four of the most common measures of trajectory similarity: longest common subsequence (LCSS)...
Article
The Region Connection Calculus (RCC) is a well-known calculus for representing part-whole and topological relations. It plays an important role in qualitative spatial reasoning, geographical information science, and ontology. The computational complexity of reasoning with RCC has been investigated in depth in the literature. Most of these works foc...
Article
Full-text available
In many applications, the environmental context for and drivers of movement patterns are just as important as the patterns themselves. This article adapts standard data mining techniques, combined with a foundational ontology of causation, with the objective of helping domain experts identify candidate causal relationships between movement patterns...
Article
Full-text available
This paper provides a decentralized and coordinate-free algorithm, called DGraF (decentralized gradient field) to identify critical points (peaks, pits, and passes) and the topological structure of the surface network connecting those critical points. Algorithms that can operate in the network without cen-tralized control and without coordinates ar...
Conference Paper
This paper proposes an in-network, decentralized algorithm for determining the qualitative spatial structure of complex a real objects, which may have multiple disconnected components. The algorithm determines both the containment relations between region components and the adjacency relations between Voronoi regions of those components. Combining...
Conference Paper
Full-text available
How does complex spatiotemporal behavior arise from, and from which, spatiotemporal knowledge? In an attempt to answer this question, we extend Valentino Braitenberg's thought experiment [3] by describing and implementing vehicles with explicit, and increasingly sophisticated, spatiotemporal knowledge. We then observe the corresponding spatiotempor...
Conference Paper
This paper proposes a decentralized and coordinate-free algorithm to monitor spatial events in a dynamic scalar field. The events that are the focus of this paper are the appearance, disappearance, and movement of “peaks” (local maxima). However, ongoing work is extending the approach to monitor the full set of critical points (peaks, pits, and pas...
Conference Paper
Event detection concerns identifying occurrence of interesting events which are meaningful and understandable. In dynamic fields, as time passes the attribute of phenomenon varies in spatial locations. Detecting events in dynamic fields requires an approach to deal with the highly granular data arriving in real time. This paper proposes a spatiotem...
Article
Full-text available
Current representations of spatial data quality (SDQ) do not adequately represent the spatial variation of SDQ. For example, a user who wants to know the positional accuracy of a feature usually has to rely on metadata statements, which usually refer to the entire data set. In reality, SDQ varies spatially; quality may be higher in some locations a...
Chapter
This chapter looks in detail at the process of decentralized algorithm simulation, and at how to validate experimentally the efficiency of an algorithm. The chapter introduces the simulation system used to implement all the protocols in this book, NetLogo. The NetLogo system is used to construct basic scalability experiments. By revisiting many of...
Article
Full-text available
Sensornetzwerke ermöglichen Umweltmonitoring in höchster räumlicher und zeitlicher Auflösung. Raum-zeitliches Data Mining bietet ein geeignetes Analysewerkzeug, um die in derartigen Messnetzen entstehenden grossen Datenmengen hinsichtlich interessanter Zusammenhänge und Muster zu untersuchen. Dieser Artikel berichtet über den Einsatz von Sequenzana...
Book
Computing increasingly happens somewhere, with that geographic location important to the computational process itself. Many new and evolving spatial technologies, such as geosensor networks and smartphones, embody this trend. Conventional approaches to spatial computing are centralized, and do not account for the inherently decentralized nature of...
Chapter
Full-text available
The procedures by which we capture and compute with spatial information are changing. This chapter sets the scene for these changes, focusing on three questions: what? why? and how? What is changing is the location where computing with spatial information occurs. Spatial information has traditionally been stored and processed in physical locations...
Chapter
This chapter presents a technique for designing decentralized spatial computing algorithms, based on the combination and extension of some conventional algorithm design tools. First, the chapter sets out a language for specifying decentralized spatial algorithms, based on the specification of local protocols for individual node behavior, rather tha...
Chapter
Evaluating efficiency helps us understand how much of a system’s resources will be consumed by an algorithm. But efficient algorithms must also be robust: able to reliably generate useful information under a range of different circumstances. Most algorithms must strike a balance between efficiency and robustness; it is frequently possible to increa...
Chapter
This chapter sets out a precise model of decentralized spatial information systems, like geosensor networks. The model has three main levels, each of which builds on structures in the previous level. First, a minimal, neighborhood-based model of geosensor networks provides the most fundamental structures for sensing and communicating information ab...
Chapter
Monitoring change is essential for many practical applications of decentralized spatial computing, because the world around us is highly dynamic. The neighborhood- and location-based algorithms discussed in the previous two chapters do not consider change in the monitored environment. Nor do they account for change in the decentralized spatial info...
Chapter
This chapter introduces the most basic type of decentralized spatial algorithm: neighborhood-based algorithms. In a neighborhood-based algorithm, nodes are assumed to have access only to minimal spatial information: the identities of their neighbors. Despite this simplicity, neighborhood-based algorithms can provide a range of important functionali...
Chapter
The coming years will no doubt yield numerous technological advances that will help to make decentralized spatial computing more commonplace. This chapter addresses a selection of important, ongoing challenges that arise from the increasing ubiquity of geosensor networks and decentralized spatial computing environments. Some of these are challenges...
Chapter
Neighborhood-based algorithms have access to only the most basic spatial information. Location-based algorithms, however, relax this restriction and assume access to a broader range of spatial information, such as the coordinate locations of nodes. As a result, location-based algorithms can provide a much broader range of functionality, including g...
Chapter
In this chapter, the author raises a number of issues surrounding the ever-growing capabilities of geoinformatics. Location privacy can be defined as the claim of individuals to determine for themselves when, how, and to what extent information about their geographic location is communicated to others. Location privacy has become an especially impo...
Article
Full-text available
Geosensor networks present unique resource constraints to spatial computation, including limited battery power, communication constraints, and frequently a lack of coordinate positioning systems. As a result, there is a need for new algorithms that can efficiently satisfy basic spatial queries within those resource constraints. This paper explores...
Article
Qualitative information about topological events, like the merging or splitting of spatial regions, has many important applications in environmental monitoring. Examples of such applications include detecting the emergence of ‘hot spots’ in sea temperature around a coral reef; or the break up and dispersion of an environmental pollution spill. This...
Article
This paper examines efficient and decentralized monitoring of objects moving in a transportation network. Previous work in moving object monitoring has focused primarily on centralized information systems, like moving object databases and GIS. By contrast, in this paper monitoring is in-network, requiring no centralized control and allowing for sub...
Article
Full-text available
Technologies for capturing large amounts of real-time and high-detail data about the environment have advanced rapidly; our ability to use this data for understanding the monitored settings for decision-making has not. Visual analytics, creating suitable tools and interfaces that combine computational powers with the human’s capabilities for visual...
Conference Paper
With the development of miniaturized sensor and communication technologies, there is an ever-growing demand for algorithms to derive high-level spatiotemporal events from large amounts of sensed data. Our previous work has already defined a decentralized, in-network approach to identifying topological relation changes between continuously evolving...
Article
Full-text available
The capability to query the topology of spatial regions is fundamental to today's centralized spatial computing systems, like spatial databases and GIS. By contrast, this paper explores decentralized algorithms for computing the topology of spatial regions in wireless sensor networks. The approach generates global topological information about regi...
Article
Location-based services require a mobile device that is able to detect the user's current position in order to return the service required. Hence, this makes the area of location privacy a growing area of social concern. Navigation systems are one example of location-aware services that track users' location information over time in order to genera...
Article
Full-text available
This article presents an algorithm for decentralized (in-network) data mining of the movement pattern flock among mobile geosensor nodes. The algorithm DDIG (Deferred Decentralized Information Grazing) allows roaming sensor nodes to ‘graze’ over time more information than they could access through their spatially limited perception range alone. The...
Article
Full-text available
The capability to query the topology of spatial regions is fundamental to today's centralized spatial computing systems, like spatial databases and GIS. By contrast, this paper explores decentralized algorithms for computing the topology of spatial regions in wireless sensor networks. The approach generates global topological information about regi...
Conference Paper
Full-text available
A key challenge facing many applications of new geosensor networks technology is to derive meaningful spatial knowledge from low-level sensed data. This paper presents a formal model for representing and computing topological relationship changes between continuously evolving regions monitored by a geosensor network. The definition of "continuity"...
Conference Paper
Full-text available
Regions which evolve over time are a significant aspect of many phenomena in the natural sciences and especially in geographic information science. Examples include areas in which a measured value (e.g. temperature, salinity, height, etc.) exceeds some threshold, as well as moving crowds of people or animals. There is already a well-developed theor...