A novel representation of bioacoustic events for content-based search in field audio data

Bioacoustic data can provide an important base for environmental monitoring. To explore a large amount of field recordings collected, an automated similarity search algorithm is presented in this paper. A region of an audio defined by frequency and time bounds is provided by a user; the content of the region is used to construct a query. In the retrieving process, our algorithm will automatically scan through recordings to search for similar regions. In detail, we present a feature extraction approach based on the visual content of vocalisations – in this case ridges, and develop a generic regional representation of vocalisations for indexing. Our feature extraction method works best for bird vocalisations showing ridge characteristics. The regional representation method allows the content of an arbitrary region of a continuous recording to be described in a compressed format.

Recognising facial expressions with noisy data

Techniques to improve the automated analysis of natural and spontaneous facial expressions have been developed. The outcome of the research has applications in several fields including national security (eg: expression invariant face recognition); education (eg: affect aware interfaces); mental and physical health (eg: depression and pain recognition).

Writing the oriental woman : an examination of the representation of Japanese women in contemporary Australian crime fiction

This study considers the challenges in representing women from other cultures in the crime fiction genre. The study is presented in two parts; an exegesis and a creative practice component consisting of a full length crime fiction novel, Batafurai. The exegesis examines the historical period of a section of the novel—post-war Japan—and how the area of research known as Occupation Studies provides an insight into the conditions of women during this period. The exegesis also examines selected postcolonial theory and its exposition of representations of the 'other' as a western construct designed to serve Eurocentric ends. The genre of crime fiction is reviewed, also, to determine how characters purportedly representing Oriental cultures are constricted by established stereotypes. Two case studies are examined to investigate whether these stereotypes are still apparent in contemporary Australian crime fiction. Finally, I discuss my own novel, Batafurai, to review how I represented people of Asian background, and whether my attempts to resist stereotype were successful. My conclusion illustrates how novels written in the crime fiction genre are reliant on strategies that are action-focused, rather than character-based, and thus often use easily recognizable types to quickly establish frameworks for their stories. As a sub-set of popular fiction, crime fiction has a tendency to replicate rather than challenge established stereotypes. Where it does challenge stereotypes, it reflects a territory that popular culture has already visited, such as the 'female', 'black' or 'gay' detective. Crime fiction also has, as one of its central concerns, an interest in examining and reinforcing the notion of societal order. It repeatedly demonstrates that crime either does not pay or should not pay. One of the ways it does this is to contrast what is 'good', known and understood with what is 'bad', unknown, foreign or beyond our normal comprehension. In western culture, the east has traditionally been employed as the site of difference, and has been constantly used as a setting of contrast, excitement or fear. Crime fiction conforms to this pattern, using the east to add a richness and depth to what otherwise might become a 'dry' tale. However, when used in such a way, what is variously eastern, 'other' or Oriental can never be paramount, always falling to secondary side of the binary opposites (good/evil, known/unknown, redeemed/doomed) at work. In an age of globalisation, the challenge for contemporary writers of popular fiction is to be responsive to an audience that demands respect for all cultures. Writers must demonstrate that they are sensitive to such concerns and can skillfully manage the tensions caused by the need to deliver work that operates within the parameters of the genre, and the desire to avoid offence to any cultural or ethnic group. In my work, my strategy to manage these tensions has been to create a back-story for my characters of Asian background, developing them above mere genre types, and to situate them with credibility in time and place through appropriate historical research.

Capturing the 'authentic voice' : challenges and opportunities for voice and self-representation in two ABC storytelling projects

In recent years there has been a noticeable move by various public institutions, such as public service broadcasters and community media organisations, to capture and disseminate the voices and viewpoints of ‘ordinary people’ through inviting them to share stories about their lives. One of the foremost objectives of many such projects is to provide under-represented individuals and groups with an opportunity to express and represent themselves; as such, the capture and broadcast of ‘authentic voices’ is a central value. This paper discusses the notion of ‘authentic voice’, and questions the framing role of public media organisations in storytelling projects that aim to provide individuals with space for self-expression and self-representation. It considers the ways in which tensions arise on multiple levels when individuals are asked to express and represent themselves within projects and spaces that are managed by institutions. This paper begins by discussing the challenges and opportunities that arise within storytelling projects that are facilitated by public institutions and community media arts organisations, and that aim to amplify the voices of “ordinary people” (Thumim, 2009). It examines ways in which ‘voice’ is facilitated, curated, broadcast and distributed within such projects, particularly questioning the ways in which project facilitation and the curation of stories for public broadcast can both help and hinder the amplification of ‘authentic voice’. Furthermore, we seek to discuss how ‘authentic voice’ is defined, and what is involved in the process of amplification. The paper moves on to discuss a case study in order to demonstrate some of the tensions that are evident within a storytelling project that is managed by a public institution – Australia’s national broadcaster – and the ways these tensions impact upon the capture and broadcast of an ‘authentic voice’ for project participants. The Australian Broadcasting Corporation’s (ABC) ‘Heywire’ project is a storytelling competition and website that aims to ‘give voice’ to 16-22 year olds who live in rural, regional and remote parts of Australia. Looking at tensions that exist on organisational, political and philosophical levels within the Heywire project reveals a number of conflicts of interest and objectives between the institution and project participants. This leads us to question whether institutionally-managed storytelling projects can effectively support individuals to have an ‘authentic voice’, and whether struggles of aims and objectives diminish the personal benefits that people may derive from expressing and representing themselves within such projects.

Semi-binary based video features for activity representation

Efficient and effective feature detection and representation is an important consideration when processing videos, and a large number of applications such as motion analysis, 3D scene understanding, tracking etc. depend on this. Amongst several feature description methods, local features are becoming increasingly popular for representing videos because of their simplicity and efficiency. While they achieve state-of-the-art performance with low computational complexity, their performance is still too limited for real world applications. Furthermore, rapid increases in the uptake of mobile devices has increased the demand for algorithms that can run with reduced memory and computational requirements. In this paper we propose a semi binary based feature detectordescriptor based on the BRISK detector, which can detect and represent videos with significantly reduced computational requirements, while achieving comparable performance to the state of the art spatio-temporal feature descriptors. First, the BRISK feature detector is applied on a frame by frame basis to detect interest points, then the detected key points are compared against consecutive frames for significant motion. Key points with significant motion are encoded with the BRISK descriptor in the spatial domain and Motion Boundary Histogram in the temporal domain. This descriptor is not only lightweight but also has lower memory requirements because of the binary nature of the BRISK descriptor, allowing the possibility of applications using hand held devices.We evaluate the combination of detectordescriptor performance in the context of action classification with a standard, popular bag-of-features with SVM framework. Experiments are carried out on two popular datasets with varying complexity and we demonstrate comparable performance with other descriptors with reduced computational complexity.

Capturing the ‘authentic voice’ : challenges and opportunities for voice and self-representation in two ABC storytelling projects

This paper discusses the opportunities and challenges that arise within storytelling projects that are facilitated by public service broadcasters and that aim to amplify the voices of ‘ordinary people’. In particular, it focuses on two of the Australian Broadcasting Corporation’s current life storytelling projects: ABC Open and Heywire.

Reflexive Dwelling: The body as representation of wall

In a play-within-a-play, the Mechanicals' production within William Shakespeare's A Midsummer Night's Dream, the character Snout announces his transformation to play the character of Wall. Snout's portrayal of Wall is both comical and menacing as he represents the forces that separate the lovers Pyramus and Thisbe. Wall becomes a subject in a manner no different from the lovers that he separates; his influence on their situation is brought to life. The unbecoming nature of walls to demarcate, separate, intimidate, influence and control is a relationship most can relate to in their experiences with architecture. It is in these moments that architecture leaps from the sphere of object into the realm of subject; where we might be involved in some intense struggle with the placement of a wall, the wall that might separate us from a lover, justice, freedom, power or privacy. This study investigates how this struggle is portrayed through the human body as representation of walls in performance.

Dictionary learning and sparse coding on Grassmann manifolds : an extrinsic solution

Recent advances in computer vision and machine learning suggest that a wide range of problems can be addressed more appropriately by considering non-Euclidean geometry. In this paper we explore sparse dictionary learning over the space of linear subspaces, which form Riemannian structures known as Grassmann manifolds. To this end, we propose to embed Grassmann manifolds into the space of symmetric matrices by an isometric mapping, which enables us to devise a closed-form solution for updating a Grassmann dictionary, atom by atom. Furthermore, to handle non-linearity in data, we propose a kernelised version of the dictionary learning algorithm. Experiments on several classification tasks (face recognition, action recognition, dynamic texture classification) show that the proposed approach achieves considerable improvements in discrimination accuracy, in comparison to state-of-the-art methods such as kernelised Affine Hull Method and graph-embedding Grassmann discriminant analysis.

A comparison of spatially explicit landscape representation methods and their relationship to stream condition

1. Biodiversity, water quality and ecosystem processes in streams are known to be influenced by the terrestrial landscape over a range of spatial and temporal scales. Lumped attributes (i.e. per cent land use) are often used to characterise the condition of the catchment; however, they are not spatially explicit and do not account for the disproportionate influence of land located near the stream or connected by overland flow. 2. We compared seven landscape representation metrics to determine whether accounting for the spatial proximity and hydrological effects of land use can be used to account for additional variability in indicators of stream ecosystem health. The landscape metrics included the following: a lumped metric, four inverse-distance-weighted (IDW) metrics based on distance to the stream or survey site and two modified IDW metrics that also accounted for the level of hydrologic activity (HA-IDW). Ecosystem health data were obtained from the Ecological Health Monitoring Programme in Southeast Queensland, Australia and included measures of fish, invertebrates, physicochemistry and nutrients collected during two seasons over 4 years. Linear models were fitted to the stream indicators and landscape metrics, by season, and compared using an information-theoretic approach. 3. Although no single metric was most suitable for modelling all stream indicators, lumped metrics rarely performed as well as other metric types. Metrics based on proximity to the stream (IDW and HA-IDW) were more suitable for modelling fish indicators, while the HA-IDW metric based on proximity to the survey site generally outperformed others for invertebrates, irrespective of season. There was consistent support for metrics based on proximity to the survey site (IDW or HA-IDW) for all physicochemical indicators during the dry season, while a HA-IDW metric based on proximity to the stream was suitable for five of the six physicochemical indicators in the post-wet season. Only one nutrient indicator was tested and results showed that catchment area had a significant effect on the relationship between land use metrics and algal stable isotope ratios in both seasons. 4. Spatially explicit methods of landscape representation can clearly improve the predictive ability of many empirical models currently used to study the relationship between landscape, habitat and stream condition. A comparison of different metrics may provide clues about causal pathways and mechanistic processes behind correlative relationships and could be used to target restoration efforts strategically.

A sparse hybrid map for vision-guided mobile robots

This paper introduces a minimalistic approach to produce a visual hybrid map of a mobile robot’s working environment. The proposed system uses omnidirectional images along with odometry information to build an initial dense posegraph map. Then a two level hybrid map is extracted from the dense graph. The hybrid map consists of global and local levels. The global level contains a sparse topological map extracted from the initial graph using a dual clustering approach. The local level contains a spherical view stored at each node of the global level. The spherical views provide both an appearance signature for the nodes, which the robot uses to localize itself in the environment, and heading information when the robot uses the map for visual navigation. In order to show the usefulness of the map, an experiment was conducted where the map was used for multiple visual navigation tasks inside an office workplace.

Integrating object locations in the memory representation of a spatial layout

The present study investigated how object locations learned separately are integrated and represented as a single spatial layout in memory. Two experiments were conducted in which participants learned a room-sized spatial layout that was divided into two sets of five objects. Results suggested that integration across sets was performed efficiently when it was done during initial encoding of the environment but entailed cost in accuracy when it was attempted at the time of memory retrieval. These findings suggest that, once formed, spatial representations in memory generally remain independent and integrating them into a single representation requires additional cognitive processes.

Predicting movie ratings from audience behaviors

We propose a method of representing audience behavior through facial and body motions from a single video stream, and use these features to predict the rating for feature-length movies. This is a very challenging problem as: i) the movie viewing environment is dark and contains views of people at different scales and viewpoints; ii) the duration of feature-length movies is long (80-120 mins) so tracking people uninterrupted for this length of time is still an unsolved problem, and; iii) expressions and motions of audience members are subtle, short and sparse making labeling of activities unreliable. To circumvent these issues, we use an infrared illuminated test-bed to obtain a visually uniform input. We then utilize motion-history features which capture the subtle movements of a person within a pre-defined volume, and then form a group representation of the audience by a histogram of pair-wise correlations over a small-window of time. Using this group representation, we learn our movie rating classifier from crowd-sourced ratings collected by rottentomatoes.com and show our prediction capability on audiences from 30 movies across 250 subjects (> 50 hrs).

An adaptive spherical view representation for navigation in changing environments

Real-world environments such as houses and offices change over time, meaning that a mobile robot’s map will become out of date. In previous work we introduced a method to update the reference views in a topological map so that a mobile robot could continue to localize itself in a changing environment using omni-directional vision. In this work we extend this longterm updating mechanism to incorporate a spherical metric representation of the observed visual features for each node in the topological map. Using multi-view geometry we are then able to estimate the heading of the robot, in order to enable navigation between the nodes of the map, and to simultaneously adapt the spherical view representation in response to environmental changes. The results demonstrate the persistent performance of the proposed system in a long-term experiment.