Computing and Information Systems - Research Publications
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ItemNo Preview AvailableModeling of microalgal shear-induced flocculation and sedimentation using a coupled CFD-population balance approach.(Wiley, 2018)In this study, shear-induced flocculation modeling of Chlorella sp. microalgae was conducted by combination of population balance modeling and CFD. The inhomogeneous Multiple Size Group (MUSIG) and the Euler-Euler two fluid models were coupled via Ansys-CFX-15 software package to achieve both fluid and particle dynamics during the flocculation. For the first time, a detailed model was proposed to calculate the collision frequency and breakage rate during the microalgae flocculation by means of the response surface methodology as a tool for optimization. The particle size distribution resulted from the model was in good agreement with that of the jar test experiment. Furthermore, the subsequent sedimentation step was also examined by removing the shear rate in both simulations and experiments. Consequently, variation in the shear rate and its effects on the flocculation behavior, sedimentation rate and recovery efficiency were evaluated. Results indicate that flocculation of Chlorella sp. microalgae under shear rates of 37, 182, and 387 s-1 is a promising method of pre-concentration which guarantees the cost efficiency of the subsequent harvesting process by recovering more than 90% of the biomass.
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ItemFinding Time for Tabletop: Board Game Play and Parenting(SAGE PUBLICATIONS INC, 2018)Hobby board gaming is a serious leisure pastime that entails large commitments of time and energy. When serious hobby board gamers become parents, their opportunities for engaging in the pastime are constrained by their new family responsibilities. Based on an ethnographic study of serious hobby board gamers, we investigate how play is constrained by parenting and how serious board gamers with these responsibilities create opportunities to continue to play board games by negotiating the context, time, location, and medium of play. We also examine how these changes influence the enjoyment players derive from board games across the key dimensions of sociality, intellectual challenge, variety, and materiality.
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ItemNo Preview AvailableMulti-objective short-term production scheduling for open-pit mines: a hierarchical decomposition-based algorithm(TAYLOR & FRANCIS LTD, 2018-12-02)This article presents a novel algorithm for solving a short-term open-pit production-scheduling problem in which several objectives, of varying priority, characterize the quality of each solution. A popular approach employs receding horizon control, dividing the horizon into N period-aggregates of increasing size (number of periods or span). An N-period mixed integer program (MIP) is solved for each period in the original horizon to incrementally construct a production schedule one period at a time. This article presents a new algorithm that, in contrast, decomposes the horizon into N period-aggregates of equal size. Given a schedule for these N periods, obtained by solving an N-period MIP, the first of these aggregates is itself decomposed into an N-period scheduling problem with guidance provided on what regions of the mine should be extracted. The performance of this hierarchical decomposition-based approach is compared with that of receding horizon control on a suite of data sets generated from an operating mine producing millions of tons of ore annually. As the number of objectives being optimized increases, the hierarchical decomposition-based algorithm outperforms receding horizon control, in a majority of instances.
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ItemAutomated human-level diagnosis of dysgraphia using a consumer tablet(NATURE PORTFOLIO, 2018-08-31)The academic and behavioral progress of children is associated with the timely development of reading and writing skills. Dysgraphia, characterized as a handwriting learning disability, is usually associated with dyslexia, developmental coordination disorder (dyspraxia), or attention deficit disorder, which are all neuro-developmental disorders. Dysgraphia can seriously impair children in their everyday life and require therapeutic care. Early detection of handwriting difficulties is, therefore, of great importance in pediatrics. Since the beginning of the 20th century, numerous handwriting scales have been developed to assess the quality of handwriting. However, these tests usually involve an expert investigating visually sentences written by a subject on paper, and, therefore, they are subjective, expensive, and scale poorly. Moreover, they ignore potentially important characteristics of motor control such as writing dynamics, pen pressure, or pen tilt. However, with the increasing availability of digital tablets, features to measure these ignored characteristics are now potentially available at scale and very low cost. In this work, we developed a diagnostic tool requiring only a commodity tablet. To this end, we modeled data of 298 children, including 56 with dysgraphia. Children performed the BHK test on a digital tablet covered with a sheet of paper. We extracted 53 handwriting features describing various aspects of handwriting, and used the Random Forest classifier to diagnose dysgraphia. Our method achieved 96.6% sensibility and 99.2% specificity. Given the intra-rater and inter-rater levels of agreement in the BHK test, our technique has comparable accuracy for experts and can be deployed directly as a diagnostics tool.
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ItemExploring Physician Attitudes Regarding Electronic Documentation of E-cigarette Use: A Qualitative Study.(SAGE Publications, 2018)BACKGROUND: In this article, we present qualitative work designed to explore physicians' attitudes toward and knowledge of electronic cigarettes (or Electronic Nicotine Delivery Systems-ENDS), particularly focusing on personal attitudes held by physicians regarding ENDS use, physician beliefs regarding the relative safety of ENDS, attitudes regarding the efficacy of ENDS as a smoking cessation tool, and how physicians' document ENDS use in the electronic health record (EHR). METHODS: We completed a total of 17 semistructured qualitative interviews with physicians in 4 different outpatient clinic locations. Clinics were selected with the goal of reaching patient panels across a diversity of socioeconomic and local geographic locations. RESULTS: The findings from our qualitative analysis suggest that physicians feel uninformed about the long-term health risks of ENDS and believe that they lack the critical medical knowledge required for discussing ENDS with their patients who smoke. Although physician responses did not endorse the view that ENDS use is a safer alternative to combustible tobacco use, approximately one-third of our physician sample did not hold strong objections to ENDS usage. Physicians placed varying degrees of importance on the issue of ENDS documentation practices. DISCUSSION: Three overarching themes were revealed from our analysis. These themes included (1) physicians' attitudes regarding the use of ENDS for smoking cessation, (2) physicians' guidance and advisement to patients in the use of ENDS for smoking cessation, and (3) current practices of clinical documentation of ENDS use in an EHR. Our qualitative results indicate that physicians in our study rarely screen patients for ENDS use, even for those patients who are both documented smokers and recipients of physician-led tobacco cessation counseling. However, most physicians agreed that the prospect of creating a structured data field specifically for the documentation of ENDS use within the EHR would result in the likelihood of increased screening and documentation of ENDS use patterns.
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ItemNo Preview AvailableTechnological Seduction and Self-Radicalization(CAMBRIDGE UNIV PRESS, 2018-09-01)Abstract Many scholars agree that the Internet plays a pivotal role in self-radicalization, which can lead to behaviors ranging from lone-wolf terrorism to participation in white nationalist rallies to mundane bigotry and voting for extremist candidates. However, the mechanisms by which the Internet facilitates self-radicalization are disputed; some fault the individuals who end up self-radicalized, while others lay the blame on the technology itself. In this paper, we explore the role played by technological design decisions in online self-radicalization in its myriad guises, encompassing extreme as well as more mundane forms. We begin by characterizing the phenomenon of technological seduction. Next, we distinguish between top-down seduction and bottom-up seduction. We then situate both forms of technological seduction within the theoretical model of dynamical systems theory. We conclude by articulating strategies for combating online self-radicalization.
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Item"Power to the people!": Social media discourse on regional energy issues in Australia(Australian Journal of Information Systems, 2018-01-01)Social media provides people from all socio-economic sectors with the opportunity to voice their opinions. Platforms such as Twitter provide the means to share one’s opinion with little effort and cost. But do these media empower everyday people to make their voice heard? In this research, we introduce a novel approach for investigating the voice of different Twitter groups on social media platforms, by combining text clustering and an analysis of cliques in the resulting network. We focus on a case study using Twitter interactions with respect to energy issues, in particular the closure of coal-fired power stations such as Hazelwood. Implications from this study will benefit stakeholders from governments to industry to the ‘common man’, in understanding how discourse on social media reflects public consumer sentiment.
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ItemSpectral-based fault localization using hyperbolic function(WILEY, 2018-03)Summary Debugging is crucial for producing reliable software. One of the effective bug localization techniques is spectral‐based fault localization. It tries to locate a buggy statement by applying an evaluation metric to program spectra and ranking program components on the basis of the score it computes. Here, we propose a restricted class of “hyperbolic” metrics, with a small number of numeric parameters. This class of functions is based on past theoretical and empirical results. We show that optimization methods such as genetic programming and simulated annealing can reliably discover effective metrics over a wide range of data sets of program spectra. We evaluate the performance for both real programs and model programs with single bugs, multiple bugs, “deterministic” bugs, and nondeterministic bugs and find that the proposed class of metrics performs as well as or better than the previous best‐performing metrics over a broad range of data.
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ItemThe Moral Depth of Human Dignity(WILEY, 2018-01)Abstract In 1971, Herbert Spiegelberg challenged philosophers to refine and deepen the vivid idea of human dignity to prevent its degeneration. Although philosophers, including Michael Rosen and Jeremy Waldron, have responded with valuable insights, the full moral depth of dignity has remained philosophically elusive. Furthermore, many philosophers still think human dignity a limited ethical concept. By integrating important alienable and inalienable dimensions of human dignity, this essay attempts to do justice to our vivid contemporary experience of dignity's moral depth. It seeks to illuminate the profound, universal worth of all humans, and the ethical force of human rights protections.
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ItemExtracting Audio Summaries to Support Effective Spoken Document Search(WILEY, 2017-09)We address the challenge of extracting query biased audio summaries from podcasts to support users in making relevance decisions in spoken document search via an audio‐only communication channel. We performed a crowdsourced experiment that demonstrates that transcripts of spoken documents created using Automated Speech Recognition (ASR), even with significant errors, are effective sources of document summaries or “snippets” for supporting users in making relevance judgments against a query. In particular, the results show that summaries generated from ASR transcripts are comparable, in utility and user‐judged preference, to spoken summaries generated from error‐free manual transcripts of the same collection. We also observed that content‐based audio summaries are at least as preferred as synthesized summaries obtained from manually curated metadata, such as title and description. We describe a methodology for constructing a new test collection, which we have made publicly available.