20 research outputs found

    A portfolio recommendation system based on machine learning and big data analytics

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    This research paper introduces a portfolio recommendation system that utilizes machine learning and big data analytics to offer a profitable stock portfolio and stock analytics via a web ap- plication. The system’s effectiveness was evaluated through backtesting and user evaluation studies, which consisted of two parts: user evaluation and performance evaluation. The findings indicate that the development of a machine learning-based portfolio recommendation system and big data analytics can effectively meet the expectations of the majority of users and enhance users’ financial knowledge. This study contributes to the growing body of research on utilizing advanced technologies for portfolio recommendation and highlights the potential of machine learning and big data analytics in the financial industry

    Multi-messenger observations of a binary neutron star merger

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    On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta

    Iron Behaving Badly: Inappropriate Iron Chelation as a Major Contributor to the Aetiology of Vascular and Other Progressive Inflammatory and Degenerative Diseases

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    The production of peroxide and superoxide is an inevitable consequence of aerobic metabolism, and while these particular "reactive oxygen species" (ROSs) can exhibit a number of biological effects, they are not of themselves excessively reactive and thus they are not especially damaging at physiological concentrations. However, their reactions with poorly liganded iron species can lead to the catalytic production of the very reactive and dangerous hydroxyl radical, which is exceptionally damaging, and a major cause of chronic inflammation. We review the considerable and wide-ranging evidence for the involvement of this combination of (su)peroxide and poorly liganded iron in a large number of physiological and indeed pathological processes and inflammatory disorders, especially those involving the progressive degradation of cellular and organismal performance. These diseases share a great many similarities and thus might be considered to have a common cause (i.e. iron-catalysed free radical and especially hydroxyl radical generation). The studies reviewed include those focused on a series of cardiovascular, metabolic and neurological diseases, where iron can be found at the sites of plaques and lesions, as well as studies showing the significance of iron to aging and longevity. The effective chelation of iron by natural or synthetic ligands is thus of major physiological (and potentially therapeutic) importance. As systems properties, we need to recognise that physiological observables have multiple molecular causes, and studying them in isolation leads to inconsistent patterns of apparent causality when it is the simultaneous combination of multiple factors that is responsible. This explains, for instance, the decidedly mixed effects of antioxidants that have been observed, etc...Comment: 159 pages, including 9 Figs and 2184 reference

    Multi-messenger Observations of a Binary Neutron Star Merger

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    On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ∼ 1.7 {{s}} with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of {40}-8+8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 {M}ȯ . An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ∼ 40 {{Mpc}}) less than 11 hours after the merger by the One-Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ∼10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ∼ 9 and ∼ 16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC 4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta.</p

    An analytical hierarchy process based procurement selection method

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    Procurement selection continues to be topical, and several advanced studies have been reported. One of the key concerns of procurement selection is how to enhance objectivity. A selection method developed using multi-attribute utility technology (MAUT) and the analytical hierarchy process (AHP) is proposed. With the input of industrial experts, critical procurement selection criteria and procurement strategies commonly used in Hong Kong were identified. Against these criteria, utility factors corresponding to various procurement strategies were then assigned by the experts to create a utility factor table. To cater for individual project characteristics, the relative importance weightings of the selection criteria were assessed using the analytical hierarchy process. Final selection was then based on the highest utility value derived from the procurement strategies, taking into account the relative importance of the selection criteria. The use of the model is illustrated with actual data.Multi-ATTRIBUTE Utility Technology Analytical Hierarchy Process Procurement Selection,

    An environmental chamber study of the characteristics of air pollutants released from environmental tobacco smoke

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    Environment tobacco smoke (ETS) is an important source of anthropogenic pollution in indoor environments. This research reports an environmental chamber study of pollutants released from ETS generated by smoking cigarettes in the chamber. Six cigarettes samples sold in Hong Kong and China were characterized. Gaseous pollutants: carbon monoxide (CO), sulphur dioxide (SO2), nitric oxide (NO), nitrogen dioxide (NO2), methane (CH4), non-methane hydrocarbon (NMHC), carbonyls and volatile organic compounds (VOCs); and particulate matter (PM), including organic carbon (OC), elemental carbon (EC) and total carbon (TC), were determined using online and offline analytical methods during smoking and post-smoking periods. Acetaldehyde, acetone and formaldehyde were the three most abundant carbonyls. A total of 18 aromatic and chlorinated VOCs were quantified. Among these, benzene and toluene were the two most abundant VOCs. OC was more dominant (\u3e 93% of TC) than EC. The amounts of tar and nicotine in the cigarettes could have a direct correlation with the PM emitted. Menthol, an additive in cigarettes, could also contribute to the ETS pollutants. The indoor ETS could be removed by a higher air exchange rate, which would also minimize secondary VOC formation

    A portfolio recommendation system based on machine learning and big data analytics

    No full text
    This research paper introduces a portfolio recommendation system that utilizes machine learning and big data analytics to offer a profitable stock portfolio and stock analytics via a web ap- plication. The system’s effectiveness was evaluated through backtesting and user evaluation studies, which consisted of two parts: user evaluation and performance evaluation. The findings indicate that the development of a machine learning-based portfolio recommendation system and big data analytics can effectively meet the expectations of the majority of users and enhance users’ financial knowledge. This study contributes to the growing body of research on utilizing advanced technologies for portfolio recommendation and highlights the potential of machine learning and big data analytics in the financial industry

    An Environmental Chamber Study of the Characteristics of Air Pollutants Released from Environmental Tobacco Smoke

    No full text
    Environment tobacco smoke (ETS) is an important source of anthropogenic pollution in indoor environments. This research reports an environmental chamber study of pollutants released from ETS generated by smoking cigarettes in the chamber. Six cigarettes samples sold in Hong Kong and China were characterized. Gaseous pollutants: carbon monoxide (CO), sulphur dioxide (SO2), nitric oxide (NO), nitrogen dioxide (NO2), methane (CH4), non-methane hydrocarbon (NMHC), carbonyls and volatile organic compounds (VOCs); and particulate matter (PM), including organic carbon (OC), elemental carbon (EC) and total carbon (TC), were determined using online and offline analytical methods during smoking and post-smoking periods. Acetaldehyde, acetone and formaldehyde were the three most abundant carbonyls. A total of 18 aromatic and chlorinated VOCs were quantified. Among these, benzene and toluene were the two most abundant VOCs. OC was more dominant (&gt; 93% of TC) than EC. The amounts of tar and nicotine in the cigarettes could have a direct correlation with the PM emitted. Menthol, an additive in cigarettes, could also contribute to the ETS pollutants. The indoor ETS could be removed by a higher air exchange rate, which would also minimize secondary VOC formation.</p
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