Computing and Information Systems - Research Publications
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ItemAn effective and versatile distance measure for spatiotemporal trajectories(SPRINGER, 2019-05)The analysis of large-scale trajectory data has tremendous benefits for applications ranging from transportation planning to traffic management. A fundamental building block for the analysis of such data is the computation of similarity between trajectories. Existing work for similarity computation focuses mainly on the spatial aspects of trajectories, but more rarely takes into account time in conjunction with space. A key challenge when considering time is how to handle trajectories that are sampled asynchronously or at variable rates, which can lead to uncertainty. To tackle this problem, we quantify trajectory similarity as an interval, rather than a single value, to capture the uncertainty that can result from different sampling rates and asynchronous sampling. Based on this perspective, we develop a new trajectory similarity measure, Trajectory Interval Distance Estimation, which models similarity computation as a convex optimisation problem. Using two real datasets, we demonstrate that our proposed measure is extremely effective for assessing similarity in comparison to existing state of the art measures.
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ItemAn automated matrix profile for mining consecutive repeats in time series(Springer Nature, 2018-01-01)A key application of wearable sensors is remote patient monitoring, which facilitates clinicians to observe patients non-invasively, by examining the time series of sensor readings. For analysis of such time series, a recently proposed technique is Matrix Profile (MP). While being effective for certain time series mining tasks, MP depends on a key input parameter, the length of subsequences for which to search. We demonstrate that MP’s dependency on this input parameter impacts its effectiveness for finding patterns of interest. We focus on finding consecutive repeating patterns (CRPs), which represent human activities and exercises whilst tracked using wearable sensors. We demonstrate that MP cannot detect CRPs effectively and extend it by adding a locality preserving index. Our method automates the use of MP, and reduces the need for data labeling by experts. We demonstrate our algorithm’s effectiveness in detecting regions of CRPs through a number of real and synthetic datasets.
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ItemCharacteristics of Local Intrinsic Dimensionality (LID) in Subspaces: Local Neighbourhood Analysis(Springer, 2019-01-01)The local intrinsic dimensionality (LID) model enables assessment of the complexity of the local neighbourhood around a specific query object of interest. In this paper, we study variations in the LID of a query, with respect to different subspaces and local neighbourhoods. We illustrate the surprising phenomenon of how the LID of a query can substantially decrease as further features are included in a dataset. We identify the role of two key feature properties in influencing the LID for feature combinations: correlation and dominance. Our investigation provides new insights into the impact of different feature combinations on local regions of the data.
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ItemImproving the quality of explanations with local embedding perturbations(ACM, 2019-07-25)Classifier explanations have been identified as a crucial component of knowledge discovery. Local explanations evaluate the behavior of a classifier in the vicinity of a given instance. A key step in this approach is to generate synthetic neighbors of the given instance. This neighbor generation process is challenging and it has considerable impact on the quality of explanations. To assess quality of generated neighborhoods, we propose a local intrinsic dimensionality (LID) based locality constraint. Based on this, we then propose a new neighborhood generation method. Our method first fits a local embedding/subspace around a given instance using the LID of the test instance as the target dimensionality, then generates neighbors in the local embedding and projects them back to the original space. Experimental results show that our method generates more realistic neighborhoods and consequently better explanations. It can be used in combination with existing local explanation algorithms.
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ItemConceptual Model for the Use of Smart Glasses in Ubiquitous Teaching (u-teaching)(AISEL, 2019-12-09)Smart glasses, a wearable headset technology, currently trending provide hands-free and augmented reality features. This paper looks at the research around mediated-reality tools to improve the delivery of education. Despite its potential, it has not seen widespread use in education. A suitable implementation framework and pedagogy have been proposed so that smart glasses can be used towards creating digitally-mediated learning (DML) environments. Aurasma is recommended as the implementation framework after a comparison with other frameworks based on factors such as cost, ease-of-use, and accessibility among others. For a suitable pedagogy, new assessment strategies, content personalization, and the use of 3-D learning spaces are recommended. It is argued, that the recommended framework and the pedagogy approach have the potential to improve learning environments for teachers and students. However, there are privacy concerns due to the pervasive nature of Augmented Reality (AR). In the current research, the overall learning environment is considered.
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ItemThe disposition of the destitute(Council to Homeless Persons, 2019)The final disposition is a term used by people in the funeral industry to refer to the burial or cremation of a dead person. The final disposition is a profoundly important event, not simply a pragmatic or material process, and its significance is expressed through ritualised performances. The disposition and its rituals are shared and communal, involving ceremonies attended by the deceased’s family, friends, and community, whilst less indirectly the disposition is shared by wider social norms and values around the proper treatment of the deceased body. Although the disposition is common to us all, then, it is also a personalised event in which the particularity of the life lived is recognised. Similarly, the place of interment, whether body or ashes, is named and marked to recognise the individual life of the deceased. Places of interment are thus not only identified, but are also accessible to family, friends and community, for the purpose of ongoing visitation and remembrance.
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ItemNo Preview Available‘Death by Twitter’: Understanding false death announcements on social media and the performance of platform cultural capital(University of Illinois Libraries, 2019)In this paper, we analyse false death announcements of public figures on social media and public responses to them. The analysis draws from a range of public sources to collect and categorise the volume of false death announcements on Twitter and undertakes a case study analysis of representative examples. We classify false death announcements according to five overarching types: accidental; misreported; misunderstood; hacked; and hoaxed. We identify patterns of user responses, which cycle through the sharing of the news, to personal grief, to a sense of uncertainty or disbelief. But we also identify more critical and cultural responses to such death announcements in relation to misinformation and the quality of digital news, or cultures of hoax and disinformation on social media. Here we see the performance of online identity through a form that we describe, following Bourdieu as ‘platform cultural capital’.
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ItemNavigating Online Down Under: International Students’ Digital Journeys in Australia(Rowman & Littlefield, 2018)Research focusing on the experiences of international students tends to centre directly on their educational experiences rather than their everyday lives outside study. Moreover, much of this research has concentrated almost exclusively on the various impacts of the physical, geographic mobility of international students as they move from one country to another, with very little exploration of their digital experiences. There also exists extensive research on the social media and information seeking experiences of young people in different regions of the world. Some of this research provides a comparison between different sources of information and uses of social media. However, there has been little research on what happens when young people move between regions or countries. Borrowing Chang and Gomes’ (2017a) concept of the digital journey, where in crossing transnational borders, migrants might also cross digital borders, this chapter provides some concrete examples of the digital experiences of international students as they transition––wholly or partly––to the Australian digital environment. How do international students transition from certain online environments into others that may be completely different, even alien, to what they have previously experienced? Referring to qualitative and quantitative data collected from three separate projects conducted between 2012 and 2017, this chapter shows that in making the digital journey, international students in Australia do not so much quit their original digital comfort zones as widen their digital horizons. Understanding international students’ digital journeys is particularly significant since it has implications for future research in international student well-being and the provision of support services for students.
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ItemNo Preview AvailableDesigning an App for Pregnancy Care for a Culturally and Linguistically Diverse Community(The Association for Computing Machinery, 2017)We report a study to design and evaluate an app to support pregnancy information provided to women through an Australian health service. As part of a larger project to provide prenatal resources for culturally and linguistically diverse groups, this study focused on the design and reception of an app with the local Vietnamese community and health professionals of a particular hospital. Our study had three stages: an initial design workshop with the hospital; prototype design and development; prototype-based interviews with health professionals and focus groups with Vietnamese women. We explore how an app of this sort must be designed for a range of different use scenarios, considering its use by consumers with a multiplicity of differing viewpoints about its nature and purpose in relation to pregnancy care.
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ItemNo Preview AvailableWhy Young Children Don’t Play: Parents’ Accounts of Non-engagement with Digital Games(Cambridge Scholars Publishing, 2019)Focusing on the digital lives of children aged eight and under, and paying attention to their parents and educators, this book showcases research findings from the UK, Denmark, Turkey, Indonesia and Australia.