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Photonic microwave true time delays for phased array antennas using a 49  GHz FSR integrated optical micro-comb source [Invited]

We demonstrate significantly improved performance of a microwave true time delay line based on an integrated optical frequency comb source. The broadband micro-comb (over 100 nm wide) features a record low free spectral range (FSR) of 49 GHz, resulting in an unprecedented record high channel number (81 over the C band)—the highest number of channels for an integrated comb source used for microwave signal processing. We theoretically analyze the performance of a phased array antenna and show that this large channel count results in a high angular resolution and wide beam-steering tunable range. This demonstrates the feasibility of our approach as a competitive solution toward implementing integrated photonic true time delays in radar and communications systems.

Author: Xu, Xingyuan, Wu, Jiayang, Nguyen, Thach G., Moein, Tania, Chu, Sai T....
Publication year: 2018
Publication type: Journal article
Status: Live|Last updated:24 April 2018 4:31 PM
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Credit card fraud detection using AdaBoost and majority voting

Credit card fraud is a serious problem in financial services. Billions of dollars are lost due to credit card fraud every year. There is a lack of research studies on analyzing real-world credit card data owing to confidentiality issues. In this paper, machine learning algorithms are used to detect credit card fraud. Standard models are firstly used. Then, hybrid methods which use AdaBoost and majority voting methods are applied. To evaluate the model efficacy, a publicly available credit card data set is used. Then, a real-world credit card data set from a financial institution is analyzed. In addition, noise is added to the data samples to further assess the robustness of the algorithms. The experimental results positively indicate that the majority voting method achieves good accuracy rates in detecting fraud cases in credit cards.

Author: Randhawa, Kuldeep, Loo, Chu Kiong, Seera, Manjeevan, Lim, Chee Peng, N...
Publication year: 2018
Publication type: Journal article
Status: Live|Last updated:24 April 2018 4:29 PM
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‘Hope givers’? A scoping review of new media and mental health in 27 Australian Christian organisations

This article explains a range of conceptual and methodological innovations in the use of new media for the clinical practice and public communication of mental health. Building on two current contexts – the emerging research area of new media and mental health, and major reform of the mental health system in Australia – this article presents a scoping review of the online communication of Christian organisations that offer mental health care in Australia. This article compares the websites of 27 Australian Christian mental health organisations, analysing these organisations’ configurations of mainstream and religious modalities of mental health care, their discursive and visual communication strategies, as well as their use of social media platforms.

Author: Chin, Esther
Publication year: 2018
Publication type: Journal article
Status: Live|Last updated:24 April 2018 4:23 PM
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Returning history to the educational formation of health professionals in Australia

History has practically vanished from allied health professional education. We ask, what kind of problem does a ‘history of the professions’ pose for health sciences curriculum? What are the implications of graduates being unschooled in the history of their profession? Literature on knowledge in the curriculum, is used to interrogate how historical knowledge has come to be constituted in professional education fields. We develop a sketch of two particular health professions – occupational therapy and physiotherapy – and ask why it might be difficult to include a history of the profession in these curricula. Our view is that by helping students to cultivate an historical imagination, they can see how their experiences are framed by a fascinating collision of ideas, politics and practices. Furthermore, attention to history can help students better situate their own uncertainties about transitioning to practice enabling them to tackle professional quandaries with hindsight, foresight and insight.

Author: Peseta, Tai, Fortune, Tracy, Jones, Adrian, Barradell, Sarah, Kennedy-...
Publication year: 2018
Publication type: Journal article
Status: Live|Last updated:24 April 2018 4:20 PM
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Machine learning differential privacy with multifunctional aggregation in a fog computing architecture

Data aggregation plays an important role in the Internet of Things, and its study and analysis has resulted in a range of innovative services and benefits for people. However, the privacy issues associated with raw sensory data raise significant concerns due to the sensitive nature of the user information it often contains. Thus, numerous schemes have been proposed over the last few decades to preserve the privacy of users’ data. Most methods are based on encryption technology, which is computationally and communicationally expensive. In addition, most methods can only handle a single aggregation function. Therefore, in this paper, we propose a multifunctional data aggregation method with differential privacy. The method is based on machine learning and can support a wide range of statistical aggregation functions, including additive and non-additive aggregation. It operates within a fog computing architecture, which extends cloud computing to the edge of the network, alleviating much of the computational bur…

Author: Yang, Mengmeng, Zhu, Tianqing, Liu, Bo, Xiang, Yang, Zhou, Wanlei
Publication year: 2018
Publication type: Journal article
Status: Live|Last updated:24 April 2018 4:07 PM
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Density-based location preservation for mobile crowdsensing with differential privacy

In recent years, the widespread prevalence of smart devices has created a new class of mobile Internet of Thing (IoT) applications. Called mobile crowdsensing, these techniques use workers with mobile devices to collect data and send it to task requester for rewards. However, to ensure the optimal allocation of tasks, a centralized server needs to know the precise location of each user, but exposing the workers’ exact locations raises privacy concerns. In this paper, we propose a data release mechanism for crowdsensing techniques that satisfies differential privacy, providing rigorous protection of worker locations. The partitioning method is based on worker density and considers non-uniform worker distribution. In addition, we propose a geocast region selection method for task assignment that effectively balances the task assignment success rate with worker travel distances and system overheads. Extensive experiments prove that the proposed method not only provides a strict privacy guarantee but also signifi…

Author: Yang, Mengmeng, Zhu, Tianqing, Xiang, Yang, Zhou, Wanlei
Publication year: 2018
Publication type: Journal article
Status: Live|Last updated:24 April 2018 4:05 PM
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Standard restrictive sternal precautions and modified sternal precautions had similar effects in people after cardiac surgery via median sternotomy (‘SMART’ Trial): a randomised trial

Question: In people who have undergone cardiac surgery via median sternotomy, does modifying usual sternal precautions to make them less restrictive improve physical function, pain, kinesiophobia and health-related quality of life? Design: Two-centre, randomised, controlled trial with concealed allocation, blinded assessors and intention-to-treat analysis. Participants: Seventy-two adults who had undergone cardiac surgery via a median sternotomy were included. Intervention: Participants were randomly allocated to one of two groups at 4 (SD 1) days after surgery. The control group received the usual advice to restrict their upper limb use for 4 to 6 weeks (ie, restrictive sternal precautions). The experimental group received advice to use pain and discomfort as the safe limits for their upper limb use during daily activities (ie, less restrictive precautions) for the same period. Both groups received postoperative individualised education in hospital and via weekly telephone calls for 6 weeks. Outcome measures…

Author: Katijjahbe, Md Ali, Granger, Catherine L, Denehy, Linda, Royse, Alista...
Publication year: 2018
Publication type: Journal article
Status: Live|Last updated:24 April 2018 4:01 PM
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Where is population II?

The use of roman numerals for stellar populations represents a classification approach to galaxy formation which is now well behind us. Nevertheless, the concept of a pristine generation of stars, followed by a protogalactic era, and finally the mainstream stellar population is a plausible starting point for testing our physical understanding of early star formation. This will be observationally driven as never before in the coming decade. In this paper, we search out observational tests of an idealised coeval and homogeneous distribution of population II stars. We examine the spatial distribution of quasars, globular clusters, and the integrated free electron density of the intergalactic medium, in order to test the assumption of homogeneity. Any real inhomogeneity implies a population II that is not coeval.

Author: Mould, J., Bianchini, F., Forbes, Duncan A., Reichardt, C. L.
Publication year: 2018
Publication type: Journal article
Status: Live|Last updated:24 April 2018 3:49 PM
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Ultra-thin MoO3 film goes wafer-scaled nano-architectonics by atomic layer deposition

From the technical and design points of view, it is quite difficult to maintain the integrity of nano-films during the deposition process to fabricate practical devices based on ultra-thin semiconductor films. Thus, defect-free wafer-scaled development of ultra-thin quasi two-dimensional (2D) oxide semiconductor films represents serious challenges. Plasma-enhanced atomic layer deposition (PE-ALD) made it possible to fabricate ultra-thin MoO3 nano-films (4.6 nm) over the wafer-scaled granular Au electrode. The detailed ALD recipe for ultra-thin MoO3 film was established and verified. The C12H30N4Mo and O2 plasma were used as Mo precursor and oxygen source, respectively. The growth of crystalline phases was observed when the ALD temperature of 250 °C was employed. Higher ALD temperature resulted in an increase of growth rate over Au substrate (1.21 Ǻ/cycle). The precise recipe design enabled the scalable fabrication of environmental sensors based on ultra-thin MoO3 films with precise thickness controllability. …

Author: Xu, Hongyan, Akbari, Mohammad Karbalaei, Hai, Zhenyin, Wei, Zihan, Hyd...
Publication year: 2018
Publication type: Journal article
Status: Live|Last updated:24 April 2018 3:48 PM
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Carbon and non-carbon support materials for platinum-based catalysts in fuel cells

Carbon and other platinum-supporting materials have been studied as electrode catalyst component of low-temperature fuel cells. Platinum (Pt) is commonly used as the catalyst due to its high electro-catalytic activity. Current research is now focusing on using either modified carbon-based or non-carbon-based materials as catalyst supports to enhance the catalytic performance of Pt. In recent years, Pt and Pt-alloy catalysts supported on modified carbon-based and non-carbon-based materials have received remarkable interests due to their significant properties that can contribute to the excellent fuel cell performance. Thus, it is timely to review this topic, focusing on various modified carbon-based supports and their advantages, limitations and future prospects. Non-carbon-based support for Pt and Pt-alloy catalysts will also be discussed. Firstly, this review summarises the progress to date in the development of these catalyst support materials; from carbon black to the widely explored catalyst support, grap…

Author: Samad, Shuaiba, Loh, Kee Shyuan, Wong, Wai Yin, Lee, Tian Khoon, Sunar...
Publication year: 2018
Publication type: Journal article
Status: Live|Last updated:24 April 2018 3:45 PM
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