Stephen Marsland

• Professor (Full) at Victoria University of Wellington

Wetlands in arid or semiarid zones are vital for maintaining biodiversity but face growing threats. Flooding regime variability is a key driver of ecological dynamism in these systems, dictating primary productivity on a large spatial scale. The functional composition or diversity of wetland‐dependent bird species has been found to be sensitive to...

Kiwi are reliant on well-developed non-visual senses to forage and breed successfully in dense New Zealand forests at night. Analysis of post-mortem records at Massey University over the last two decades has shown increasing numbers of cases of mortality due to misadventure in kiwi of all ages. Drowning was found to be a common cause of death, and...

Sensor-based human activity recognition has been extensively studied. Systems learn from a set of training samples to classify actions into a pre-defined set of ground truth activities. However, human behaviours vary over time, and so a recognition system should ideally be able to continuously learn and adapt, while retaining the knowledge of previ...

We often wish to classify objects by their shapes. Indeed, the study of shapes is an important part of many scientific fields, such as evolutionary biology, structural biology, image processing and archaeology. However, mathematical shape spaces are rather complicated and nonlinear. The most widely used methods of shape analysis, geometric morphome...

A de Rham p -current can be viewed as a map (the current map) between the set of embeddings of a closed p -dimensional manifold into an ambient n -manifold and the set of linear functionals on differential p -forms. We demonstrate that, for suitably chosen Sobolev topologies on both the space of embeddings and the space of p -forms, the current map...

Sound recordings are used in various ecological studies, including wildlife monitoring by acoustic surveys. Such surveys often require automatic detection of target sound events in the large amount of data produced. However, current processing methods, especially those relying on sound intensity for detection, are severely impacted by wind, which c...

Human emotions are dynamic in nature. The intensity with which they are felt changes over time, and they have a natural timescale of expression, from onset to decay. Further, emotions shade from one to another, and many feelings are built up of blends of pure emotions. In order to represent this complex reality visually, a variety of models of the...

Many time series problems feature epidemic changes-segments where a parameter deviates from a background baseline. Detection of such changepoints can be improved by accounting for the epidemic structure, but this is currently difficult if the background level is unknown. Furthermore, in practical data the background often undergoes nuisance changes...

Bioacoustics has emerged as a useful method of data collection and analysis for diverse animals in a wide range of environments and has helped to describe, monitor, and conserve some of Africa’s species biodiversity. However, little is known about how much it contributes to the continent’s research corpus. We report results from a systematic review...

Acoustic playback is commonly used to study wild birds, with applications as diverse as investigating behaviours, ascertaining the presence of rare and elusive species, and attracting individuals to a location. The number of studies employing playback is growing larger every year because it is easy to apply, increasingly affordable and very effecti...

Sound recordings are used in various ecological studies, including acoustic wildlife monitoring. Such surveys require automatic detection of target sound events. However, current detectors, especially those relying on band-limited energy, are severely impacted by wind. The rapid dynamics of this noise invalidate standard noise estimators, and no sa...

Long-term soundscape recordings are useful for a variety of applications, most notably in bioacoustics. However, the processing of such data is currently limited by the ability to efficiently and reliably detect the target sounds, which are often sparse and overshadowed by environmental noise. This paper proposes a sound detector based on changepoi...

Passive acoustic surveys provide a convenient and cost-effective way to monitor animal populations, and methods for conducting and analysing such surveys are undergoing rapid development. However, no standard metric exists to evaluate the proposed changes. Furthermore, the metrics that are commonly used are specific to a single stage of the survey...

We often wish to classify objects by their shapes. Indeed, the study of shapes is an important part of many scientific fields such as evolutionary biology, structural biology, image processing, and archaeology. The most widely-used method of shape analysis, Geometric Morphometrics, assumes that that the mathematical space in which shapes are repres...

Acoustic recordings of birdsong are increasingly used to monitor our native bird populations. In order to estimate populations from call rates, it is necessary to either recognise individuals from their calls, or localise the calls. While call direction can be identified using time difference of arrival to the components of a microphone array, esti...

Processes such as growth and atrophy cause changes through time that can be visible in a series of medical images, following the hypothesis that form follows function. As was hypothesised by D’Arcy Thompson more than 100 years ago, models of the changes inherent in these actions can aid understanding of the processes at work. We consider how image...

BACKGROUND: In object oriented (OO) software systems, class size has been acknowledged as having an indirect effect on the relationship between certain artifact characteristics, captured via metrics, and faultproneness, and therefore it is recommended to control for size when designing fault prediction models. AIM: To use robust statistical methods...

Passive acoustic surveys provide a convenient and cost-effective way to monitor animal populations. Methods for conducting and analysing such surveys, especially for performing automated call recognition from sound recordings, are undergoing rapid development. However, no standard metric exists to evaluate the proposed changes. Furthermore, most me...

Many time series problems feature epidemic changes - segments where a parameter deviates from a background baseline. The number and location of such changes can be estimated in a principled way by existing detection methods, providing that the background level is stable and known. However, practical data often contains nuisance changes in backgroun...

We study a class of general purpose linear multisymplectic integrators for Hamiltonian wave equations based on a diamond-shaped mesh. On each diamond, the PDE is discretized by a symplectic Runge--Kutta method. The scheme advances in time by filling in each diamond locally. We demonstrate that this leads to greater efficiency and parallelization an...

Ecoacoustics has the potential to provide a large amount of information about the abundance of many animal species at a relatively low cost. Acoustic recording units are widely used in field data collection, but the facilities to reliably process the data recorded – recognizing calls that are relatively infrequent, and often significantly degraded...

Classifying acoustic units is often a key step in studying repertoires and sequence structure in animal communication. Manual classification by eye and ear remains the primary method, but new tools and techniques are urgently needed to expedite the process for large, diverse datasets. Here we introduce Koe , an application for classifying and analy...

The nonlinear spaces of shapes (unparameterized immersed curves or submanifolds) are of interest for many applications in image analysis, such as the identification of shapes that are similar modulo the action of some group. In this paper we study a general representation of shapes that is based on linear spaces and is suitable for numerical discre...

The routine collection of long‐time acoustic recordings of animals in the field presents new challenges in data analysis. While many terabytes of data are collected annually, effective use of this noisy, highly variable data require skilled humans to manually identify calls. While computer programs to automatically analyse these recordings are beco...

Post-marital residence is a sex-biased dispersal defined by the place where a newly-wed couple lives after marriage. Common choices for this practice include patrilocal residence, where the couple lives with the man's family, and matrilocal residence, where they live with the woman's family. Deviations from accepted practice typically invoke strong...

Autonomous recording units are now routinely used to monitor birdsong, starting to supplement and potentially replace human listening methods. However, to date there has been very little systematic comparison of human and machine detection ability. We present an experiment based on broadcast calls of nocturnal New Zealand birds in an area of natura...

These are the proceedings of the workshop "Math in the Black Forest", which brought together researchers in shape analysis to discuss promising new directions. Shape analysis is an inter-disciplinary area of research with theoretical foundations in infinite-dimensional Riemannian geometry, geometric statistics, and geometric stochastics, and with a...

BACKGROUND: In object oriented (OO) software systems, class size has been acknowledged as having an indirect effect on the relationship between certain artifact characteristics, captured via metrics, and fault-proneness, and therefore it is recommended to control for size when designing fault prediction models. AIM: To use robust statistical metho...

An early step in bottom-up diagram recognition systems is grouping ink strokes into shapes. This paper gives an overview of the key literature on automatic grouping techniques in sketch recognition. In addition, we identify the major challenges in grouping ink into identifiable shapes, discuss the common solutions to these challenges based on curre...

Where a newly-married couple lives, termed post-marital residence, varies cross-culturally and changes over time. While many factors have been proposed as drivers of this change, among them general features of human societies like warfare, migration and gendered division of subsistence labour, little is known about whether changes in residence patt...

The use of automatic acoustic recorders is becoming a principal method to survey birds in their natural habitats, as it is relatively noninvasive while still being informative. As with any other sound, birdsong degrades in amplitude, frequency, and temporal structure as it propagates to the recorder through the environment. Knowing how different bi...

Conservationists are increasingly using autonomous acoustic recorders to determine the presence/absence and the abundance of bird species. Unlike humans, these recorders can be left in the field for extensive periods of time in any habitat. Although data acquisition is automated, manual processing of recordings is labour intensive, tedious, and pro...

en Bayesian networks are now pedagogically factorised in R with tremendous applications by Mario Scutari and Jean‐Baptiste Denis’ book.

There has been a variety of crossover operators proposed for Real-Coded Genetic Algorithms (RCGAs), which recombine values from the same location in pairs of strings. In this article we present a recombination operator for RC- GAs that selects the locations randomly in both parents, and compare it to mainstream crossover operators in a set of exper...

In machine learning, one often encounters data sets where a general pattern is violated by a relatively small number of exceptions (for example, a rule that says that all birds can fly is violated by examples such as penguins). This complicates the concept learning process and may lead to the rejection of some simple and expressive rules that cover...

The nonlinear spaces of shapes (unparameterized immersed curves or submanifolds) are of interest for many applications in image analysis, such as the identification of shapes that are similar modulo the action of some group. In this paper we study a general representation of shapes that is based on linear spaces and is suitable for numerical discre...

Registration of images parameterised by landmarks provides a useful method of describing shape variations by computing the minimum-energy time-dependent deformation field that flows one landmark set to the other. This is sometimes known as the geodesic interpolating spline and can be solved via a Hamiltonian boundary-value problem to give a diffeom...

Registration of images parameterised by landmarks provides a useful method of describing shape variations by computing the minimum-energy time-dependent deformation field that flows one landmark set to the other. This is sometimes known as the geodesic interpolating spline and can be solved via a Hamiltonian boundary-value problem to give a diffeom...

One application of Ambient Intelligence (AmI) that supports people in their daily activities is the smart home, which has become a popular topic for research over the past 10 years. The smart home can support the inhabitant in a variety of ways, such as watching for potential risks, detecting any abnormality, adapting the home for environmental con...

There has been a variety of crossover operators proposed for Real-Coded Genetic Algorithms (RCGAs), which recombine values from the same location in pairs of strings. In this article we present a recombination operator for RC- GAs that selects the locations randomly in both parents, and compare it to mainstream crossover operators in a set of exper...

Identifying when different images are of the same object despite changes caused by imaging technologies, or processes such as growth, has many applications in fields such as computer vision and biological image analysis. One approach to this problem is to identify the group of possible transformations of the object and to find invariants to the act...

Automatic recording of birdsong is becoming the preferred way to monitor and quantify bird populations worldwide. Programmable recorders allow recordings to be obtained at all times of day and year for extended periods of time. Consequently, there is a critical need for robust automated birdsong recognition. One prominent obstacle to achieving this...

Birdsong examples in Fig 10. (ZIP)

Bird call examples in Fig 8. (ZIP)

Overlapped birdsong examples in Fig 12. (ZIP)

North Island robin song example in Fig 13. (ZIP)

Identifying human behaviours in smart homes from sensor observations is an important research problem. The addition of contextual information about environmental circumstances and prior activities, as well as spatial and temporal data, can assist in both recognising particular behaviours and detecting abnormalities in these behaviours. In this pape...

One application of Ambient Intelligence (AmI) that supports people in their daily activities is the smart home, which has become a popular topic for research over the past 10 years. The smart home can support the occupant in a variety of ways: watching for potential risks, detecting any abnormality, adapting home for environmental conditions, induc...

The statistical analysis of data lying on a differentiable, locally Euclidean, manifold introduces a variety of challenges because the analogous measures to standard Euclidean statistics are local, that is only defined within a neighbourhood of each datapoint. This is because the curvature of the space means that the connection of Riemannian geomet...

Engineering performance-critical systems often requires manual, expensive fine-tuning of critical application parts such as start-up routines, authentication sequences and transactions. It is highly desirable to protect this investment by regression tests that indicate when performance characteristics such as memory usage or thread allocation chang...

It is well known that many real-world networks (‘complex’ networks), such as social, biological and communication networks, have distinctive topological features. However, in general, it is an open question whether or not these features can provide any algorithmic benefits. In this paper, we introduce ideas from the area of parametrized complexity...

A Proven, Hands-On Approach for Students without a Strong Statistical Foundation Since the best-selling first edition was published, there have been several prominent developments in the field of machine learning, including the increasing work on the statistical interpretations of machine learning algorithms. Unfortunately, computer science student...

The main way birds communicate is acoustically using calls or songs. Generally, bird call/song serves as species specific signature that enables other birds and humans to identify which species generated the song providing enough information to detect and monitor bird species effectively. However, automated bird song recognition is still at a primi...

HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et a la...

Circular dependencies between software artefacts are widely considered as problematic. However, empirical studies of Java programs have shown that most programs are riddled with circular dependencies. This seems to imply that not all circular dependencies are as detrimental to software quality as previously thought. Clearly, a better understanding...

We develop a framework for deriving governing partial differential equations for variational problems on spaces of conformal mappings. The main motivation is to obtain differential equations for the conformal motion of free boundary continua, of interest in image and shape registration. A fundamental tool in the paper, the Hodge─Morrey─Friedrichs d...

Variants of malware and exploits are emerging globally at an ever-increasing rate. There is a need to automate their detection by observing their footprints over network streams, but signature-based intrusion detection systems alone cannot cope with the dynamic nature of modern security threats. In this paper, we approach intrusion detection as a c...

The recognition of human behaviour from sensor observations is an important area of research in smart homes and ambient intelligence. In this chapter, the authors introduce the idea of spatio-temporal footprints, which are local patterns in space and time that should be similar across repeated occurrences of the same behaviour. They discuss the spa...

It is well known that many real-world networks (`complex' networks), such as social, biological, and communication networks, have distinctive topological features. However, in general, it is an open question whether or not these features can provide any algorithmic benefits. In this paper we introduce ideas from the area of parameterized complexity...

Many real networks exhibit strongly-skewed, heavy-tailed degree distributions, one of the indicators of so-called 'complex' networks, and there is a lot of current research in this area. Much of this research requires the generation of random graphs with the same degree distribution as one another, and it is important that these random graphs shoul...

There has been a lot of research interest in research smart homes for behaviour recognition and related tasks supporting the elderly living alone. Amongst the many challenges of such research are the selection of sensors and the secure storage of data. However, there are other important issues such as reliable data collection, acceptance of sensor...

The recognition of basic human emotions based on facial points has been studied extensively for many years. Since complex emotions are comprised of a number of the basic emotions, in order to identify them some way to interpolate between known basic emotions must be identified. In this paper, we introduce a finite mixture model to recognise complex...

Emotions are dynamic. They vary continuously with regard to intensity, duration, persistence with time, and other attributes. In addition, their appearance on the face of subjects varies, and the transition in facial expressions is based on both the change in emotion and physiological constraints. In this paper, we examine the trajectories between...

The recognition of basic human emotions based on facial points has been studied extensively for many years. Since complex emotions are comprised of a number of the basic emotions, in order to identify them some way to interpolate between known basic emotions must be identified. In this paper, we introduce a finite mixture model to recognise complex...

Although web page and computer interface developers generally have little experience in generating effective colour schemes, colour selection appears rarely in user interface design literature, and there are few tools available to assist in appropriate choice of colours. This article describes an algorithmic technique for applying colour harmony ru...

Although webpage and computer interface designers generally have little experience at generating effective colour schemes, colour selection appears only rarely in user interface design literature. This article describes the experimental evaluation of an algorithmic technique that applies colour harmony rules to the selection of colour schemes for c...

Semantic mapping of static environments has become a hot topic in robotics. The aim of the Mermaid project was to investigate the transfer of a sensor data interpretation approach for mapping to the problem of activity recognition in smart home applications such as elderly care. The basic structure of the semantic mapping approach, i.e., to assembl...

The ubiquitous nature of miniature wireless sensors and rapid developments in the wireless network technology have revolutionized home monitoring and surveillance systems. The new means and methods of collecting data efficiently and have led to novel applications for indoor wireless sensor networks. The applications are not limited to solely monito...

In spatio-temporal reasoning, granularity is one of the factors to be considered when aiming at an effective and efficient representation of space and time. There is a large body of work which addresses the issue of granularity by representing space and time on a qualitative level. Other approaches use a predefined scale which implicitly determines...

The problem of behaviour recognition based on data from sensors is essentially an inverse problem: given a set of sensor observations, identify the sequence of behaviours that gave rise to them. In a smart home, the behaviours are likely to be the standard human behaviours of living, and the observations will depend upon the sensors that the house...

The chapter describes the sociological perspective of monitoring technologies and debates its method for analysing social implications of scientific and technical developments. It is articulated in five sections dedicated to social and privacy aspects involved in social analysis of technologies. Particular attention is devoted to social network ana...

In this chapter, the authors propose an approach to indoor human daily activity recognition that combines motion data and location information. One inertial sensor is worn on the thigh of a human subject to provide motion data while a motion capture system is used to record the human location information. Such a combination has the advantage of sig...

The authors describe a generic framework for model-based behaviour interpretation and its application to monitoring aircraft service activities. Behaviour models are represented in a standardised conceptual knowledge base using OWL-DL for concept definitions and the extension SWRL for constraints. The conceptual knowledge base is automatically conv...

Once a smart home system moves to a multi-resident situation, it becomes significantly more important that individuals are tracked in some manner. By tracking individuals, the events received from the sensor platform can then be separated into different streams and acted on independently by other tools within the smart home system. This process imp...

Having computers recognise emotions has benefits for human-computer interaction, psychology, and behavioural analysis. Unfortunately it is a very difficult problem, partly because humans can, to some extent, control the appearance of an emotion on their faces. In this paper we show that building statistical shape models of different parts of the fa...

We propose a Parallel Class Expression Learning algorithm that is inspired by the OWL Class Expression Learner (OCEL) and its extension --- Class Expression Learning for Ontology Engineering (CELOE) --- proposed by Lehmann et al. in the DL-Learner framework. Our algorithm separates the computation of partial definitions from the aggregation of thos...

Metrics on shape space are used to describe deformations that take one shape to another, and to determine a distance between them. We study a family of metrics on the space of curves, that includes several recently proposed metrics, for which the metrics are characterised by mappings into vector spaces where geodesics can be easily computed. This f...

We consider the problem of constructing a discrete differential geometry defined on nonplanar quadrilateral meshes. Physical models on discrete nonflat spaces are of inherent interest, as well as being used in applications such as computation for electromagnetism, fluid mechanics, and image analysis. However, the majority of analysis has focused on...

In this paper we describe context awareness for a smart home using previously collected qualitative data. Based on this, context experts estimate to what extent a behavior is likely to occur in the given situation. The experts' estimations are then combined using Dempster-Shafer Theory. The result can be used to (a) predict the most likely behavior...

In this article a tool for the analysis of population-based EAs is used to derive asymptotic upper bounds on the optimization time of the algorithm solving Royal Roads problem, a test function with plateaus of fitness. In addition to this, limiting distribution of a certain subset of the population is approximated.

The main result is the identification of the orthogonal complement of the subalgebra of conformal vector field inside the algebra of all vector fields of a compact flat 2-manifold. As a fundamental tool, the complete Hodge decomposition for manifold with boundary is used. The identification allows the derivation of governing differential equations...

In recent years there has been considerable interest in methods for diffeomorphic warping of images, with applications e.g.\ in medical imaging and evolutionary biology. The original work generally cited is that of the evolutionary biologist D'Arcy Wentworth Thompson, who demonstrated warps to deform images of one species into another. However, unl...